Apparatus mixing, filtering, reacting and drying materials

Information

  • Patent Grant
  • 6290383
  • Patent Number
    6,290,383
  • Date Filed
    Wednesday, June 24, 1998
    26 years ago
  • Date Issued
    Tuesday, September 18, 2001
    23 years ago
Abstract
The present invention is an apparatus for processing material having a chamber (100), a rotatably driven shaft (104) extending within the chamber to which is attached at least one element (110) which engages the material (102) in the chamber during rotation thereof and a drive mechanism (150, 170, 200 and 250) for rotating the driven shaft. The process includes (a) driving the driven shaft in one direction while the chamber contains the material in a liquid form while at least one of heat or a vacuum is applied to the chamber from a source 101 to reduce an amount of liquid present in the liquid material; (b) after step (a) driving the driven shaft while at least heat or vacuum is applied to the chamber to reduce an amount of liquid in the material in a first direction to cause the at least one element to engage the material through an angular rotation which lifts the material upward in the chamber while at least heat or vacuum is applied to the chamber to reduce an amount of liquid vehicle in the material in a second direction, opposite to the first direction, to cause the at least one element to engage the material through an angular rotation which lifts the material upward in the chamber; and after step (b), driving the driven shaft in one direction while at least heat or vacuum is applied to the chamber to reduce an amount of liquid to particularize the material.
Description




TECHNICAL FIELD




The present invention relates to methods and apparatus for processing materials including mixing, drying, reacting and filtering.




BACKGROUND ART





FIGS. 1

illustrates an apparatus


10


which is disclosed in the Assignee's U.S. Pat. No. 5,275,484 which is incorporated herein by this reference in its entirety. The apparatus


10


continually processes liquids and/or solids (materials) including mixing, drying or reacting. A chamber


12


is used for processing of materials. The chamber


12


is comprised of a plurality of zones


14


,


16


,


18


which may be varied in number and dimension depending upon the particular application and the degree of processing required. The apparatus is supported by a stand


19


. The zones


14


,


16


,


18


are defined by an inner wall


20


of the chamber


12


and weir


22


which is disposed at a boundary between zones within the chamber. An opening


24


extends vertically upward from the weir


22


between adjacent zones within the chamber


12


for permitting the materials to pass from one zone to an adjacent zone. The opening may be produced by a manually adjustable gate


26


which slides horizontally to permit adjustment of the opening


24


. A shaft


32


is driven by a motor and gear box (prime mover)


34


for rotating a series of elements


36


which are connected to the shaft by radially extending members


38


. The shaft


32


is rotatably supported by bearings


33


. The elements


36


contact the material within the zones


14


,


16


,


18


to promote mixing, drying, and reacting, etc., of the materials within the zones. The elements


36


may have differing shapes promoting agitation, mixing, drying and reactions by moving material contacted by moving elements


36


. The design, number and orientation of the mixing elements within each of the zones


14


,


16


,


18


is varied to control retention time of the matter within the zones. Contacting of the elements


36


with the materials within the zones controls the rate of movement of the material through the opening


24


between the zones and axially within a zone. Each of the elements


36


typically will have substantial surface area


37


which is inclined with respect to the axis of rotation of the shaft


32


to provide a plow-like function to move the material axially within the zone toward the opening


24


.




Increasing of the rate of rotation of the shaft imparts additional energy to the materials within each of the zones


14


,


16


,


18


which increases the rate of movement of the materials through the opening


24


between the zones and decreasing the rate of rotation Decreases the rate of movement of materials through the opening. Additionally, the opening


24


between adjacent zones may be adjusted to be larger to increase the rate of movement of materials through the opening and may be adjusted to be smaller to decrease the rate of movement of materials through the opening.




A programmed controller


40


, having an electrical control and logic panel, which may be in the form of a programmed control logic, controls the operation of the various components in the system including the rate of rotation of the shaft


32


produced by the prime mover


34


. The programmed controller


40


may be programmed to control a rate of rotating of the shaft by the prime mover


34


to produce programmed contact of the elements


36


with the materials within the zones


14


,


16


,


18


, a programmed rate of movement of the materials through the opening


24


between the zones and axially within a zone and a programmed dwell time of materials within each zone. The controller is programmable to cause the prime mover


34


rotating the shaft


32


for a first time interval at a lower speed to provide a lower rate of movement of the materials through the opening


24


between zones


14


,


16


,


18


, a longer dwell time of a processing of the materials within the zones and to rotate the shaft for a second time interval at a higher speed than the lower speed to provide a higher rate of movement of the materials through the opening between the zones and a shorter dwell time of processing of materials within the zone. Alternatively, the controller


40


is programmable to cause the prime mover to rotate the shaft at a set speed to provide a continuous rate of processing and movement of materials through the opening between zones. The controller


40


may be implemented in any programmable device including a microprocessor or other programmable analog or digital device. The controller


40


includes a memory (not illustrated) for storing a plurality of different programs used for processing different materials which provides the ability to choose stored programs to economically process diverse types of materials without substantial manual overhead, especially when the controller controls all of the variable elements within the apparatus as described below.




A material input


42


controls the flow of materials to be processed by the apparatus and controls the addition of the materials into the first zone


14


and a material output


44


controls the flow of materials which has been finally processed in the final processing zone


18


from the apparatus. Both the material input and the material output


42


and


44


are atmospherically sealed to the chamber


12


with seals (not illustrated) so that non-atmospheric conditions may be provided within the material input, the material output and inside of the chamber during processing. A non-atmospheric pressure source


45


is coupled to the interior of the chamber


12


at one or more of the zones


14


,


16


,


18


or to the material input


42


or material output


44


to provide either a vacuum to promote drying and the removal of other vapors within the materials being processed or pressurization with gas used for processing materials within the chamber such as during chemical reactions within the chamber. The material input


42


and the material output


44


are provided with valuing to control the addition of materials for processing within the chamber and the removal of processed materials from the chamber while maintaining non-atmospheric pressure. The valving in the material input


42


and the material output


44


may be a pair of valves


46


and


48


which are connected in series in conduit within the material input


42


and the material output


44


.




The valves


46


and


48


may be of diverse form including, but not limited to, slide gate valves as illustrated or ball or butterfly valves, etc. In order to control the pressure within the chamber


12


at non-atmospheric pressure, the valves


46


and


48


are operated under the control of the controller


40


to control movement of the materials through the material input


42


into the first zone


14


.




The lower valve


48


in the material input


42


is controlled by the controller


40


to be closed while the upper valve


46


is controlled by the controller


40


to be open to seal the chamber


12


from atmospheric pressure and the hopper


106


during conveying of materials by the material input for addition to the first zone


14


. Thereafter, the upper valve


48


is closed by the controller


40


to seal the materials conveyed by the material input from atmospheric pressure between the upper and lower valves. Finally, the lower valve


48


is opened by the controller


40


to cause the materials between the lower and upper valves to be added to the first zone


14


. The above-described sequence of operation of the valves in the material output


42


is repeated cyclically during the continuous processing performed by the invention.




The lower valve


48


in the material input


44


is controlled by the controller


40


to be closed while the upper valve


46


in the material output is opened during discharge of materials from the last zone


18


. Thereafter, the upper valve


46


in the material output


44


is closed by the controller


40


to seal the discharged materials between the valves from atmospheric pressure. Finally, the lower valve


48


is opened to cause the materials between the lower and upper valves


46


and


48


of the material output


44


to be moved between the valves typically by the effect of gravity. The above-described sequence of operation of the valves in the material output


44


is repeated cyclically during the continuous processing produced by the present invention. Vacuum, pressure or vibrating devices can be added to aid in the charging or discharging of the valves.




The material input


42


may contain miscellaneous processing equipment


51


such as, but not limited to, an agglomerating device for spraying liquid into powder introduced into hopper


106


to produce agglomeration of the powder or a high intensity agitator for purposes of predispersion of minor ingredients prior to introduction into the first zone


14


of the chamber


12


.

FIG. 6

described below illustrates an agglomerating device which may be disposed within the material input


42


.




The chamber


12


contains the following additional structures. A removable lid


56


is mounted in the top section of the chamber


12


to permit access to each of the zones


14


,


16


,


18


including adjustment of the openings


24


. A filtration screen may be disposed in one or more of the zones


14


,


16


,


18


in either the bottom or in the side of the chamber


12


for permitting liquid separation of liquids and solids disposed within the zones by liquid flowing through the screen outside the chamber. The filtration screen is periodically back-flushed during operation to prevent accumulation of excessive solids from occluding (blinding) the screen which would interfere with draining of liquid from the chamber when the invention is being used to filtrate materials containing undesired liquid components through the filtration screen. Viewing ports


60


may be disposed in the side walls of the chamber


12


to permit visualization of the processing within the chamber


12


. Additionally, spray balls


62


may be installed to permit cleaning of the interior of the chamber


12


between processings.




A jacket may be provided in contact with the inner wall


20


of the chamber


12


and/or a jacket in contact with the weir(s)


22


and/or a hollow shaft


32


(not illustrated) for receiving cooling or heating fluids for controlling the temperature within the chamber for a suitable fluid source (not illustrated). A plurality of fluid ports are provided for coupling fluid to the jacket and outputting fluid from the jacket from the fluid source. Heated fluid may be coupled to the jacket to heat the chamber


12


to promote drying of product which is typically conducted under sub-atmospheric pressure. Cooling fluid may be coupled to the jacket to cool the chamber


12


to absorb heat generated by exothermic chemical reactions taking place within the zones


14


,


16


,


18


. Diverse types of heating and cooling fluids may be utilized in conjunction with the jacket to provide precise control of temperature conditions within the chamber


12


. For example, the jacket may be sectorized (not illustrated) such that each processing zone


14


,


16


,


18


is thermally coupled to a single jacket which receives fluid having the required temperature for processing the materials within the processing zone coupled to the jacket sector. Other means of introducing heating, such as gasses, infrared or microwave (not illustrated) may be used for thermal treatment.




The material output


44


may include an agitator disposed within the final zone


18


for contacting the material to cause the material to flow into the material output. The agitator may include an eccentric


112


mounted on the shaft


32


. A member


114


is connected to the eccentric which extends into the material output


44


with rotation of the eccentric causing the member to reciprocate within the material output. As a result, any tendency of a finally processed solid to agglomerate or bridge is reduced to provide a uniform flow rate of finally processed material from the material output


44


. Vibrators or air pads may also be used in the material movement through the input and output devices


42


and


44


.





FIG. 2

illustrates a perspective view of a prior art multipurpose mixer which is disclosed in the Assignee's U.S. Pat. No. 4,705,222 which is incorporated herein by reference in its entirety. The apparatus


10


′ is positioned in an angular orientation for performing a specific mixing operation. The main parts of the apparatus


10


′ are a drum assembly


12


′, including a driven main axial drive shaft (not illustrated), a main housing


14


′, a detent pin mechanism


17


′ for locking the drum in any one of a plurality of angular positions. A support stand


16


′ is provided which supports the axis of rotation


17


′ of the driving assembly


12


′. A control panel


18


′ contains controls for activating and controlling the speed of two motor drives and an ammeter used for monitoring the current draw by the motor which drives the main drive shaft located axially within the drum assembly


12


. Preferably the motor for driving the main driven shaft is of variable speed with at least two selectable speeds to permit the drive shaft to be driven at speeds designed for diverse types of mixing operations as described below. The second motor drive


20


′ extends through the outside wall of the drum assembly orthogonally into the chamber formed by the drum for driving a high sheer deagglomerating impeller. The drum has a first end


22


′ which is removable from cylindrical section


23


′. A clamp


24


′ is attached to the outside cylindrical section


23


′ and the first end


22


′ of the drum assembly


12


′ to lock the first end in place during operation. The clamp


24


′ also locks the drum assembly


12


′ to the main housing


14


′. The part of the clamp


24


′ which clamps the first end of the drum in place is openable to permit the first end to be removed to place missing element assemblies on the main drive shaft. The first end


22


′ of the drum assembly


12


′ includes a port


26


′ which is located near the periphery of the first end at a position offset from the centrally disposed drive shaft. The port


26


′ includes a hollow cylindrical section


28


′ which has a first end which communicates with the interior of the drum assembly


12


′ and a second end having a closure


30


′ which is removable to permit materials to be placed inside of and removed from the drum assembly


14


′. Typically, the materials are added to the drum while it is in its “vertical up” position and removed when it is in its “vertical down” position. The closure


30


′ is held in place by a clamp


32


′. A plurality of holes


42


′ are drilled in the side panel of the main housing


14


′ or receiving the detent pin assembly


30


′ mounted in the upright portion of the support stand


16


′. The controls for the motor drives are conventional.





FIG. 3

illustrates a sectional view of the apparatus of

FIG. 2

used in the horizontal mixing mode. The drive shaft


46


′ is driven by a variable speed motor


48


′ which is controlled from the control panel


18


′. The drive shaft


46


′ is rotatably supported in the second end


50


′ of the drum assembly


12


′ by a bearing


52


′. A seal


54


′ is provided for preventing the bearing


52


′ from being contacted by materials being mixed within the drum assembly


12


′. The drive shaft


46


′ has an extension


56


′ which is coupled to the variable speed motor


48


′ to couple rotary motion to the mixing elements


56


′ which are attached at spaced apart locations to a hollow cylindrical sleeve


58


′ which has an inner surface which contacts the outer surface of the drive shaft


46


′. A hole


60


′ is diametrically drilled through the cylindrical sleeve


58


′ and the drive shaft


46


′ for receiving a pin (not illustrated) for locking the cylindrical sleeve


58


′ which drives the mixing elements


56


′ to the drive shaft


46


′. Preferably, the mixing elements


56


′ are plow-shaped elements of well-known construction. The cylindrical section


23


′ is of double walled construction to form a jacket


61


′ useful for applications requiring heating or cooling. The port


61


″ is coupled to a suitable heat or cooling source to control the temperature of the mixing chamber. Each element


56


′ contains at least one sloped surface


62


′ which is inclined upward toward the drive shaft


46


′ to impart lift to materials being contacted by rotation of the mixing element. The individual mixing elements


56


′ are attached to the hollow cylindrical sleeve


58


′ by radial arms


64


′. The arm


64


′ located closest to the second end


50


′ of the drum assembly


12


′ has a 90° bend to permit the attachment point to the hollow cylindrical sleeve


58


′ to be axially offset from the position of the mixing element within the drum assembly


12


′. The remaining three arms


64


′ are straight. The end of the drive shaft


46


′ is offset slightly from the first end


22


′ of the drum assembly. A deagglomerating impeller


68


′ projects orthogonally inward from the inner wall of the drum assembly


12


′ at a point midway between the first end


22


′ and the second end


50


′. The deagglomerating impeller


68


′ includes a blade assembly


72


′ which is attached to a drive shaft


74


′ which is coupled to a motor


20


′. The deagglomerating impeller drive shaft


74


′ is sealed against leakage by a sealing assembly


76


′. The deagglomerating impeller


68


′ is used to control particle size of materials being mixed within the drum assembly


12


′ and to disperse any liquids. While the present invention is preferably used to perform horizontal mixing with the mixing element assembly as illustrated, it should be understood that other mixing element assemblies may be used which are designed for mixing particular materials or performing particular types of mixing actions while the drive shaft


46


′ is in the horizontal position.




U.S. Pat. No. 5,261,746 discloses a method of transporting and blending slurries in a sealed chamber with an oscillating paddle system. The system of the '746 Patent is used in conjunction with viscous slurries such as mash comprised of insolubles carried in a liquid. A driven shaft which rotates about a horizontal axis oscillates through a limited degree of rotation in order to lift the fluid mass from confining ends of the chamber to the center portion of the container. The paddles are offset by 90° so that lifting of the fluid mass at opposite sides of the container occurs upon rotation of the shaft in alternate directions. Rotation in each direction between 90° to 360° is described. The liquid content of the chamber is not varied during rotation.




Most mixers, filters, dryers and chemical reactors utilize rotary motion inside of a cylindrical vessel which is either positioned vertically or horizontally. The use of rotary motion in these devices is complete rotary motion in which a mixing shaft is rotated in one direction to which are attached one or mixing elements which are typically rotated at either relatively slow or fast speeds.




Rotary motion in one direction in mixing devices is typified by several problems. The mixing action is typically so intense that it can change the particle size of the product mixed. During washing and filtration, the complete rotary motion can stir a slurry too fast making it harder to disengage during the filtration mode.




During drying of some products, the material changes from a liquid phase typically in the form of a slurry to a very viscous doughy phase which causes the product to form spaghetti-like strings that wrap around and stick to the drive shaft. The drying cycle is either stopped or substantially slowed because of inadequate contact with a heat and/or vacuum source. Large agglomerates and heavy buildup around the drive shaft inhibit further processing. These problems can occur when the assignee's aforementioned patents are utilized to perform drying operations in which the drive shaft is disposed in a nonvertical mode.




Additionally, certain types of substances which require a gentle mixing, coating or drying are damaged by contact caused by the mixing elements rotating at high speed in devices which use one-way rotation of driven shaft, such as the prior art apparatuses described above in conjunction with

FIGS. 1-3

.




DISCLOSURE OF THE INVENTION




The present invention is a process for processing material with a processing system having a chamber, a rotatably driven shaft extending within a chamber to which is attached at least one element which engages the material in the chamber during rotation thereof and a drive mechanism for rotating the driven shaft and an apparatus for processing material in which oscillating rotational movement of the drive shaft is utilized in a first direction to cause the at least one element to engage the material with an angular rotation which lifts the material in the chamber and then in a second direction, opposite to the first direction, to cause the at least one element to engage the material with an angular rotation which lifts the material in the chamber. The oscillating rotational movement is typically an intermediate phase of a process wherein a liquid material is processed with a three-phase process in which the first phase of the process has the driven shaft rotated in one direction during which a liquid is evaporated from the material followed by the aforementioned rotation in the first and second directions, followed finally by rotation of the driven shaft in one direction to particularize the material. However, it should be understood that the present invention is not limited to the aforementioned three-step process. Preferably, in applications in which the aforementioned three phase process is utilized when the material is typified by forming a viscous doughy-like consistency which will stick to the drive shaft, the intermediate phase of the process involving rotation in the first and second directions does not lift the material upward beyond a level of the material over the driven shaft in the chamber which prevents the material from falling onto the drive shaft and sticking thereto which interferes with or prevents effective drying as in the prior art.




In a preferred application of the present invention, independent power sources are utilized for rotating the driven shaft in the one direction during the first and third phases of the process and the oscillating rotation in the first and second directions during the second phase of the process. Processing required for the first and third phases of the process is effectively performed by a relatively high speed rotation of the driven shaft for agitating the highly liquid phase in the first part of the process and granulating the product during the final phase of the process after the intermediate processing of oscillating the shaft in the first and second directions. A combination of heat and/or vacuum is preferably used in the three phases of the process to facilitate the removal of the liquid.




The independent drive utilized for the intermediate phase oscillation of the driven shaft in the first and second directions permits effective reversing of the drive shaft at low speed to accomplish lifting of the material being processed, which may be the form of a dough-like slurry. The independent drive of the driven shaft during second phase typically is geared down from a prime mover smaller than the prime mover for the first and third phases to apply increased torque to the drive shaft at low speed to facilitate the alternative lifting of material. Furthermore, the use of independent drives permits the intermediate phase of the process to be disabled to permit conventional one-way shaft rotation to be used for mixing, drying, reacting and filtering operations as in the prior art. One preferred form of the independent drive utilizes either a single or double rack and pinion drive to apply torque directly to the output of the driven shaft and another preferred form uses a pair of electric motors connected to the driven shaft through gear reducers and a clutch. The mixing elements are spaced from the interior surface of the chamber to avoid direct contact which would shorten their useful life because of frictional engagement with the mixing chamber.




The oscillation of the driven shaft allows the one or more elements attached thereto to rock back and forth to avoid making a complete revolution while lifting the product in contact with them to promote driving off of the liquid typically in the presence of heat and/or vacuum while keeping the material from wrapping around the driven shaft because it is not lifted directly above the shaft to a position at which it would fall from the mixing elements into contact with the driven shaft and stick thereto. The oscillation of the at least one element attached to the driven shaft may be made gentle to avoid applying successive shear to aggregate which produces overwetting. The oscillating motion during the intermediate phase of the process converts the product from a dough-like consistency into semi-dry clusters which are broken up in the final one-way rotational direction of the driven shaft using an existing built-in mill which chops and converts the material to a powder without sticking to the shaft or the walls of the chamber to solve the problem of the prior art discussed above.




It should be understood that various forms of independent drive mechanisms may be used, such as plural motors, rack and pinion drives, simple harmonic motion, levers, linkages, speed reducing devices, indexing drives, variable speed electrical motor drives, electromechanical drives, etc. Furthermore, it should be understood that the invention is not limited to any particular form of element attached to the driven shaft.




A process for processing material with a processing system having a chamber, a rotatably driven shaft extending within the chamber to which is attached at least one element which engages the material in the chamber during rotation thereof and a drive mechanism for rotating the driven shaft in accordance with the invention includes while the chamber is partially filled with the material rotating the driven shaft in a first direction to cause the at least one element to engage the material through an angular rotation which lifts the material upward beyond a level of the material in the chamber without reaching a position which is directly above the driven shaft and then rotating the driven shaft in a second direction, opposite to the first direction, to cause the at least one element to engage the material through an angular rotation which lifts the material upward beyond the level of the material in the chamber without reaching a position which is directly above the driven shaft. The material during the rotation of the driven shaft in the first and second directions is typically sufficiently viscous that the material would stick to the driven shaft if the material were to contact the driven shaft. The driven shaft is driven through a plurality of sequential cycles with each cycle including rotation in the first and second directions. Furthermore, the driven shaft is rotated in one direction to cause the material to increase in viscosity during rotation in one direction prior to rotating the driven shaft in the first and second directions; and after completion of rotating the driven shaft in the first and second directions, rotating the driven shaft in one direction to particularize the material. Heat and/or vacuum may be applied to the material in the chamber during the first phase of the process of rotating the driven shaft in the first direction, during the rotating of the driven shaft in the first and second directions during the intermediate phase of the process and during the rotating of the driven shaft in the one direction in the last phase of the process during rotation in the one direction to drive off liquid present in the material. The at least one element is spaced from a wall of the chamber during rotation to prevent excessive wear.




Preferably, the drive mechanism includes a first prime mover for rotating the driven shaft in the one direction and a second prime mover for rotating the driven shaft in the first and second directions.




An apparatus for processing material in accordance with the invention includes a chamber for containing the material, a rotatably driven shaft extending within the chamber to which is attached at least one element which engages the material in the chamber during rotation thereof, a drive mechanism for rotating the driven shaft, and a control for controlling the drive mechanism wherein the control controls the drive mechanism to rotate the driven shaft in the first direction to cause the at least one element to engage the material while the chamber is partially filled with the material through an angular rotation which lifts the material upward beyond a level of the material in the chamber without reaching a position which is directly above the driven shaft and then the control controls the drive mechanism to rotate the driven shaft in a second direction, opposite to the first direction, to cause the at least one element to engage the material through an angular rotation which lifts the material upward beyond a level of material in the chamber without reaching a position which is directly above the driven shaft. The control controls the drive shaft to drive the driven shaft in the first and second directions while the material is sufficiently viscous so that the material would stick to the driven shaft if the material were to contact the driven shaft. The control controls the drive mechanism to rotate the driven shaft through a plurality of sequential driven cycles with each cycle including rotation in the first and second directions. The control controls the drive mechanism to rotate the driven shaft in one direction to cause the material to increase in viscosity during the rotation in one direction prior to controlling the drive mechanism to rotate the driven shaft in the first and second directions; and after completion of rotating of the driven shaft in the first and second directions, the control controls the drive mechanism to rotate the driven shaft in one direction to particularize the material. A heat source and/or a vacuum source may respectively add heat an/or apply vacuum to the material during rotation of the driven shaft in the one direction and in the first and second directions to drive off liquid present in the material. The at least one element is spaced from a wall of the chamber to prevent excessive wear. The drive mechanism preferably includes a first prime mover which is controlled by the control which rotates the driven shaft in the one direction; and a second prime mover, which is controlled by the control which rotates the driven shaft in the first and second directions.




A process for processing material with a processing system having a chamber, a rotatably driven shaft extending within the chamber to which is attached at least one element which engages the material in the chamber during rotation thereof and a drive mechanism for rotating the driven shaft includes rotating the driven shaft with the drive mechanism in one direction while the chamber contains the material in a liquid form while at least one of heat and/or a vacuum is applied to the chamber to drive off liquid present in the liquid material; after rotating of the driven shaft in one direction, rotating the driven shaft with the drive mechanism while at least one of heat or vacuum is applied to the chamber to drive of f the liquid present in the material in a first direction to cause the at least one element to engage the material through an angular rotation which lifts the material and then rotating the driven shaft in a second direction, opposite to the first direction to cause the at least one element to engage the material through an angular rotation which lifts the material upward; and after rotating the driven shaft in the first and second directions rotating the driven shaft in one direction while at least heat and/or a vacuum is applied to the chamber to drive off liquid present in the material to particularize the material. During rotation in the first and second directions, the material is lifted above a level of the material in the chamber without reaching a position which is directly above the driven shaft. The material is sufficiently viscous during rotation in the first and second directions that the material would stick to the driven shaft if the material were to contact the driven shaft. The driven shaft is driven through a plurality of sequential cycles with each cycle including rotation in the first and second directions.




A process for processing material with a processing system having a chamber, a rotatably driven shaft extending within the chamber to which is attached at least one element which engages the material in the chamber during rotation thereof and a drive mechanism for rotating the driven shaft in accordance with the invention includes applying at least one of heat or vacuum to the chamber which drives off liquid present in the material while rotating the driven shaft in a first direction to cause the at least one element to engage the material through an angular rotation which lifts the material upward and then rotating the driven shaft in a second direction, opposite to the first direction, to cause the at least one element to engage the shaft through an angular rotation which lifts the material upward. The material is lifted upward during the rotation in the first and second directions above a level of material in the chamber without reaching a position which is directly above the driven shaft. The material is sufficiently viscous during rotation in the first and second directions that the material would stick to the driven shaft if the material were to contact the driven shaft. While applying at least one of heat or vacuum to the chamber which drives off liquid present in the material, the driven shaft is driven through a plurality of sequential cycles with each cycle including rotation in the first and second directions. While applying at least one of heat or vacuum to the chamber which drives of f liquid present in the chamber rotating the driven shaft in one direction to cause the material to increase in viscosity prior to rotating the driven shaft in the first and second directions; and after completion of rotating the driven shaft in the first and second directions, rotating the driven shaft in one direction to particularize the material.




An apparatus for processing material in accordance with the invention includes a chamber for containing the material, a rotatable driven shaft extending within the chamber to which is attached at least one element which engages the material in the chamber during rotation thereof, a drive mechanism for rotating the driven shaft, at least one of a vacuum source or a heat source applied to the chamber which drives off liquid present in the material during rotation of the driven shaft by the drive mechanism and a control for controlling the drive mechanism and wherein the control controls the drive mechanism to rotate the driven shaft in a first direction to cause at least one element to engage the material through an angular rotation which lifts the material upward and then the control controls the drive mechanism to rotate the driven shaft in a second direction, opposite to the first direction, to cause the at least one element to engage the material through an angular rotation which lifts the material. The material is lifted upward during the rotation in the first and second directions above a level of material in the chamber without reaching a position which is directly above the driven shaft. The control controls the drive mechanism to rotate the driven shaft in the first and second directions while the material is sufficiently viscous that the material would stick to the driven shaft if the material were to contact the driven shaft. The control controls the drive mechanism to rotate the driven shaft through a plurality of sequential cycles with each cycle including rotation in the first and second directions. The control controls the drive mechanism to rotate the driven shaft in one direction to cause the material to increase in viscosity prior to controlling the drive mechanism to rotate the driven shaft in the first and second directions; and after completion of rotating of the driven shaft in the first and second directions, the control controls the drive mechanism to rotate the driven shaft in one direction to particularize the material.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a side elevational view of a mixing apparatus in accordance with the Assignee's U.S. Pat. No. 5,275,484;





FIG. 2

is an isometric view of a mixing system in accordance with the Assignee's U.S. Pat. No. 4,705,222;





FIG. 3

illustrates a sectional view of the mixing chamber of

FIG. 2

of the Assignee's U.S. Pat. No. 4,705,222;





FIGS. 4-6

respectively illustrate the three phases of processing of material in accordance with a preferred embodiment of the present invention.





FIG. 7

illustrates a first embodiment of a drive mechanism for providing the rotational motion in accordance with

FIGS. 4-6

;





FIGS. 8A and 8B

respectively illustrate a second embodiment of a drive mechanism for providing the rotational motion in accordance with

FIGS. 4-6

;





FIGS. 9A and 9B

illustrate a third embodiment of a drive mechanism for providing the rotational motion in accordance with

FIG. 5

;





FIGS. 10A and 10B

illustrate a fourth embodiment of a drive mechanism for providing the rotational motion in accordance with

FIG. 5

; and





FIGS. 11A-11D

illustrate various configurations of the at least one element which is attached to the driven shaft for performing the processing phases of FIGS.


4


-


6


.











Like reference numerals identify like parts throughout the drawings.




BEST MODE CARRYING OUT THE INVENTION




The present invention may be practiced in diverse forms of apparatus, such as, but not limited to, the apparatuses described in the Assignee's U.S. Pat. Nos. 4,705,222 and 5,275,484 described above. In practicing the present invention with apparatuses in accordance with the aforementioned patents, the drive mechanism and control is modified to provide both driving of the drive shaft therein in one direction as is conventionally done in those apparatuses and oscillatory drive through a limited degree of rotation as described below with reference to

FIG. 5

in first and second directions. Preferred forms of the drive mechanism are described below with reference to

FIGS. 7

,


8


A and


8


B,


9


A and


9


B, and


10


A and


10


B. The details of the infeed and outfeed of processed materials into and out of the chamber may be in accordance with the systems as described in the Assignee's above-referenced patents and are not hereinafter described. However, it should be understood that the present invention is not limited to material infeed and outfeed mechanisms in accordance with the above-referenced patents.





FIGS. 4-6

illustrate an end view of the processing chamber


100


during three processing phases which are a preferred application of the present invention in which a material initially in liquid form is processed sequentially from a liquid phase of

FIG. 4 through a

dough-like phase of

FIG. 5

to a granulation phase of FIG.


6


. However, it should be understood that the present invention is not limited to the processing phases of

FIGS. 4-6

and further that the oscillation of the drive shaft at a lower speed than the one-way rotation of

FIGS. 4 and 6

through a limited angular degree of rotation may be used alone to coat or otherwise process materials which would be damaged by the one-way rotation of the drive shaft at high speed. The chamber


100


has applied thereto a combination of heat and/or vacuum from source


101


in accordance with the prior art of

FIGS. 1-3

for promoting the removal of the liquid


102


which contains the material which is being particularized typically into fine granules. Drive shaft


104


is rotated in one direction


106


to agitate the material


102


with a drive mechanism (not illustrated) as described below with reference to

FIGS. 7

,


8


A and B,


9


A and B and


10


A and B. The drive shaft


104


has at least one and preferably a plurality of arms


108


which project radially outward to a point of attachment of elements


110


which are spaced from an inside wall of chamber


100


to prevent excessive wear and are designed to perform diverse functions, such as mixing, milling, etc. The bidirectional arrows


109


represent heating or cooling fluid from a source


111


of heating or cooling fluid which facilitates heat transfer to and from the product. Different forms of the elements


110


may be used to practice the present invention and examples of suitable elements are discussed below with reference to

FIGS. 11A-11D

. As is illustrated in

FIG. 4

, the chamber


100


at the beginning of processing typically contains a quantity of liquid


102


having a liquid level


112


above the shaft but which does not completely fill the chamber which permits the application of vacuum, forced hot air or the application of heat through the interior wall


114


, as generically indicated by heat and/or vacuum source


101


and may be by means of a thermal jacket to drive off the liquid to produce during the continued rotation of the drive shaft


104


a continuous reduction in the amount of liquid present in the liquid material


102


. The process of

FIG. 4

is conventional and is the first phase of the three phase process of

FIGS. 4-6

which ultimately results in a fine granulated product.





FIG. 5

illustrates the second intermediate phase of the process in which the liquid level has been reduced to reduce the product level typically to below the shaft


104


. The shaft


104


is driven alternatively in a first direction


116


and a second direction


118


. Preferably, the shaft


104


is driven by the drive mechanism (not illustrated) in the first direction


116


to cause at least one element


110


to engage the material


102


through an angular rotation which lifts the material upward beyond the level


112


of the material in the chamber


100


without reaching a position which is directly above the driven shaft


104


and then drives the driven shaft in the second direction


118


, opposite to the first direction, to cause the at least one element


110


to engage the material


102


through an angular rotation which lifts the material upward beyond the level of the material in the chamber without reaching a position which is directly above the driven shaft. The rotation in the first and second directions


116


and


118


is repeated sequentially many times, is typically at a much lower rotational speed then the rotations in the directions


106


and


124


as illustrated in

FIGS. 4 and 6

and is preferably powered by a drive mechanism which is independent of the drive mechanism which provides the rotation in the direction


106


in illustrated FIG.


4


and in direction


124


as illustrated in FIG.


6


. During the processing of

FIG. 5

, the application of heat and/or vacuum from heat/or vacuum source


101


to the chamber


100


drives off additional liquid to cause the material to reach a doughy-like consistency where it is quite heavy and tacky and has a viscosity where it will form string-like sections


120


which would wrap around the shaft


104


if the elements


110


were to lift the material below the level


112


above top dead center of the shaft


104


and beyond. As illustrated, the string-like sections


120


fall back into the material


102


, as illustrated in

FIG. 5

, without engaging the driven shaft


104


. The alternative rotation of the driven shaft in the first and second directions


116


and


118


through a limited degree of angular rotation preferably without the elements


110


reaching top dead center eliminates the problem of the prior art where wrapping of the thick viscous material around the driven shaft resulted from rotation of the drive shaft in one direction when the material was sufficiently viscous to form the string-like sections. The string-like sections, if wrapped around the driven shaft, produce a substantial decrease in the efficiency of the drying process with possible total failure and further result in excessive energy consumption typified by a requirement of much higher torque to power the rotational elements. The relatively thick viscosity of the material required the motor driving the driven shaft to lift a substantial amount of the material sticking to the elements upward resulting in a substantial consumption of energy because the electric motor was operating near a stalling speed.




As is illustrated in

FIG. 5

, the material below the level


112


is of a doughy-like consistency which tends to form agglomerates


121


as the liquid content is continually reduced within the chamber


100


by the application of heat and/or vacuum from the heat or vacuum source


101


.




The processing of

FIG. 5

, while preferably being utilized in the three phase process of

FIGS. 4-6

, has applications which do not require a sequence of going from a liquid phase, as illustrated in

FIG. 4

, to a particularized, pulverized and granulated material, as illustrated in FIG.


6


. For example, certain materials which require a surface coating to be gently applied to the material without breaking the material into pieces, may take advantage of the alternative rotation of the elements


110


in the first and second directions


116


and


118


at a slower controlled speed than the speed of rotation which typifies the prior art rotation in one direction. The materials being processed with the oscillating motion of

FIG. 5

do not have to be of the thick viscous consistency typifying the process, as illustrated in

FIG. 5

, where the materials would, if lifted directly above the shaft


104


, stick directly thereto causing substantial interference with or outright failure of the drying and particularizing operation in accordance with excessive energy consumption.





FIG. 6

illustrates the third phase of processing in accordance with a preferred application of the present invention in which the material is granulated into fine particles


122


with the application of heat and/or vacuum from source


101


. In this phase, the drive shaft


104


is again driven in one direction


124


in accordance with the prior art to produce particularization.




However, because of the efficient removal of the liquid produced by the alternative rotations of the drive shaft


104


in the first direction


116


and the second direction


118


as illustrated in

FIG. 5

, the energy consumption and the time of processing to drive off the liquid to a point where granulation may take place has been substantially enhanced (reduced). The increased efficiency of the processing of

FIG. 5

, which lessens the overall processing time to perform the processing phases of

FIGS. 4-6

, is resultant from the elements


110


alternatively moving in the first and second directions


116


and


118


which applies a gentle but effective lifting of the material to minimize coating of the inside wall


114


of the chamber


100


, coating of the driven shaft


104


and provides a greater exposure of surface area of the material being processed to heat and/or vacuum from source


101


which promotes driving off of the liquid present therein. The rotation in the first and second directions


116


and


118


does not produce damage to the consistency of the material being processed and prevents the material from being taken out of thermal contact with the inside wall


114


of the chamber


100


which reduces the efficiency of heat transfer through the chamber wall and further reduces the surface area exposed to vacuum and/or heat applied to the space in the chamber above the material level


112


from the heat and/or vacuum source


101


. The rotation of the shaft


104


in one direction


124


in

FIG. 6

occurs for a sufficient time for the combination of heat and/or vacuum applied to the interior of the chamber


100


from heat and/or vacuum source


101


to be sufficient to remove the liquid and to bring the dryness of the material to a point where conventional grinding can occur under the action of the one or more elements


110


because the material is no longer sufficiently wet to stick together.





FIG. 7

illustrates a first embodiment


150


of a drive mechanism, which contains first and second motors


152


and


154


which are under the control of a control generally in accordance with the Assignee's patents, which has been modified to control motor


154


to produce the rotation of the driven shaft


104


in the first and second directions (not illustrated) to be selectively activated to produce the rotations illustrated in

FIGS. 4-6

. The motor


152


supplies the power for rotation of the drive shaft


104


in the phases of

FIGS. 4 and 6

. A speed reducer


158


applies speed reduction to the output shaft


156


of motor


152


. Motor


154


applies power to the shaft


104


through a second speed reducer


160


and belt drive


162


which drives a pulley


164


which is attached to the input of speed reducer


158


. Clutch


166


under the control of the control (not illustrated) selectively disengages motor


154


from driving shaft


104


when motor


152


is activated. The combination of the speed reducers


158


and


160


permits a smaller motor


154


to be used in comparison to motor


152


because of the additional speed reduction which has sufficient torque to drive the driven shaft


104


at a relatively slower rotation in directions


116


and


118


than the one-way rotations


106


and


124


produced by motor


152


and to also drive the rotor of motor


152


. When the operational phase of

FIG. 5

is required, motor


154


is started with the clutch


162


engaged to drive through gear reducer


160


and gear reducer


158


to driven shaft


104


to achieve a lower rotational speed than utilized for the rotation of

FIGS. 4 and 6

. The motor


154


is driven by the combination of a timer and a direction reverser to produce the alternative rotation in directions


116


and


118


. It should be understood that the chamber


100


may be in accordance with diverse designs not limited to the configuration of the Assignee's Patents described in

FIGS. 1-3

and may be as generally described in

FIGS. 4-6

.





FIGS. 8A and 8B

illustrate a second embodiment


170


of a drive mechanism which may be utilized in accordance with the present invention for producing the rotation of the drive shaft


104


in the first direction


116


and the second direction


118


as illustrated in FIG.


5


.

FIG. 8A

represents the drive mechanism


170


in an engaged position and

FIG. 8B

illustrates the drive mechanism in a disengaged position. The drive mechanism


170


is hydraulically or pneumatically powered utilizing a first power cylinder


172


for stroking a rack


174


which meshes with pinion


176


attached to shaft


104


and an activation cylinder


178


which pivots the rack


174


from the engaged position as illustrated in

FIG. 8A

to the disengaged position as illustrated in FIG.


8


B. All operations of the drive mechanism are under the control of the controller of

FIGS. 1-3

as modified to permit two-way rotation. The bidirectional arrow


180


represents the rotation in the first direction


116


and the second direction


118


of FIG.


5


. When the piston of the cylinder


178


is activated, arm


182


′ extends causing the meshing of the rack


174


with the pinion


176


. The pinion


176


is provided with sufficient play to allow the teeth respectively of the rack


174


and the pinion


176


to engage when the rack is pivoted toward the pinion regardless of the relative position of the teeth. The power cylinder


172


strokes the rack


174


up and down as illustrated in FIG.


8


A. Limit switches (not illustrated) in association with the rack


174


sense the limits of motion of the rack


174


between the ends of stroke thereof. Each limit switch senses the end of stroke which provides a signal to the control (not illustrated) of the main cylinder


172


to reverse its direction of extension causing the rack


174


to reverse direction which changes the direction of rotation of the pinion


176


. A selector switch (not illustrated) associated with the control may be used to switch the system from the motion of

FIG. 4

to the bidirectional rotation of FIG.


5


and back to the rotation of FIG.


6


.




This switch activates the cylinder


178


to engage and disengage the rack and pinion drive as illustrated. The power cylinder


172


is capable of supplying the high torque which is necessary to perform the lifting function of the viscous material


121


of FIG.


5


.




Furthermore, from time to time it is desirable to rotate the chamber


100


relative to the engagement with the elements


110


in order to sweep out a different angular section


114


of the chamber


100


. The aforementioned switching may be utilized to deactivate the hydraulic cylinder


172


to permit the chamber to be moved relative to the elements


110


(indexing) to sweep out a different angular section of the inside surface


114


of the chamber


100


wall to facilitate increased working of the material to prevent collection on the inside wall of the chamber in an area not swept out by the elements


110


moving through their limited angular oscillation at a spaced position from the inside surface


114


of the chamber


100


. This indexing operation may be visualized with respect to

FIG. 5

by stopping the rotation of shaft


104


and moving the chamber


100


through a relative angular rotation sufficient that the outside surface of the elements


110


sweep out a different inside angular path of the surface


114


of the chamber


100


.





FIGS. 9A and 9B

respectively illustrate a third embodiment


200


of the drive mechanism in accordance with the present invention for producing the rotation of the driven shaft


104


in the first and second directions


116


and


118


. In the disengaged position, as illustrated in

FIG. 8B

, rotation of the shaft


104


may occur in direction


181


corresponding to directions


106


and


124


as illustrated in

FIGS. 4 and 6

.

FIG. 9A

illustrates the engaged position and

FIG. 9B

illustrates the disengaged position for producing the rotations in directions


116


and


118


. A pinion


202


is attached to driven shaft


104


as in the embodiment


170


of the drive mechanism described above in conjunction with

FIGS. 8A and 8B

. A rack


204


is attached to a block


206


containing a ball screw which is threaded to engage a corresponding threaded drive rod


208


which is driven through a speed reducer


210


by reversible motor


212


. The bidirectional arrow


214


represents the rotation of the drive shaft


104


in the first direction


116


and in the second direction


118


. Switches (not illustrated), similar to those described above with reference to

FIGS. 8A and 8B

, sense the limits of travel which are indicated by the ends of the arrow


216


. A conventional direction reversing circuit is used to cause the motor to rotate in the first and second directions


116


and


118


. While preferably the connection assembly


206


is a ball screw but this embodiment is not limited thereto. The position of the chamber


100


may be indexed relative to the driven shaft


104


in the same manner as described above in conjunction with

FIGS. 8A and 8B

. Additionally, limit switches are used (not illustrated) in a manner analogous to the embodiment of

FIGS. 8A and 8B

to control reversing of motion of the driven shaft at the end of stroke of the block


206


.





FIGS. 10A and 10B

illustrate a fourth embodiment


250


of a drive mechanism for driving shaft


104


with

FIG. 10A

illustrating the engaged position and

FIG. 10B

illustrating the disengaged position. The operation of the fourth embodiment


250


is similar to the embodiment of the drive mechanism


170


of

FIGS. 8A and 8B

except that an additional power and activation cylinders are used to


35


engage and disengage a second rack


256


from driving pinion


254


. In the engaged position of

FIG. 10A

, rotation represented by arrow


252


corresponds to the rotational directions


116


and


118


of FIG.


5


. In the disengaged position, as illustrated in

FIG. 10B

, rotation of the shaft


104


may occur in one direction


262


corresponding to directions


106


and


124


as illustrated in

FIGS. 4 and 6

. A pair of main actuators


258


stroke the pair of racks


256


between travel limits in the same manner as described above in conjunction with the driving mechanism


170


of

FIGS. 8A and 8B

. The bidirectional arrow


253


represents the rotation of the driven shaft


104


in the first and second directions


116


and


118


of FIG.


5


. Similarly, actuator


260


positions the pair of racks


256


between the engaged position as illustrated in FIG.


10


A and the disengaged position as illustrated in FIG.


10


B. It should be understood that the drive mechanism for the shaft


104


for producing rotation in one direction represented by arrow


262


to provide the processing illustrated in

FIGS. 4 and 6

may be accomplished with a main motor


152


in accordance with FIG.


7


. The position of the chamber may be indexed relative to the driven shaft


104


in the same manner as described above in conjunction with

FIGS. 8A and 8B

. Additionally, limit switches are used (not illustrated) in a manner analogous to the embodiment of

FIGS. 8A and 8B

to control reversing of motion of the driven shaft


104


at the end of the stroke of the racks


256


.




The prime mover and drive mechanism for rotating the shaft


104


in the one direction


106


and


124


, as illustrated in

FIGS. 4 and 6

, is coupled to the shaft


104


at a point projecting orthogonally from the plane of

FIGS. 8A and 8B

,


9


A and


9


B and


10


A and


10


B, and may be similar to motor


152


and speed reducer of FIG.


7


.





FIGS. 11A-11D

illustrate different configurations of elements


110


which may be utilized with the processing phases of

FIGS. 4-6

. However, it should be understood that the present invention is not limited to the elements


110


as illustrated in

FIGS. 11A-11D

.




The element


110


of

FIG. 10A

is a single V-shaped element


260


. Outside peripheral surface


261


during normal operation is spaced a small distance from the inside circumference


114


of the chamber


100


, represented by the dashed line


262


, to lessen wear.




The element


110


of

FIG. 10B

is double V-shaped element


264


. Outside outer peripheral surface


266


during normal operation is spaced a small distance from the inside circumference


114


of the chamber


100


(represented by dashed line


262


) to lessen wear.




The element


110


of

FIG. 11C

is a scraping style element


268


. Outside peripheral surface


270


during normal operation is spaced a small distance from the inside circumference


114


of the chamber


100


, represented by a dashed line


262


to lessen wear.




The element


110


illustrated in

FIG. 11D

is a paddle style element


272


. Outside periphery


274


during normal operation is spaced a small distance from the inside circumference


114


of the chamber


100


represented by dashed line


262


to lessen wear.




These diverse shapes of elements


110


, which are preferably utilized for mixing and granulation, facilitate the lifting operation of

FIG. 5

as well as the agitation and removal of the liquid in FIG.


4


and granulation in FIG.


6


.




While the invention has been illustrated in the form of its preferred embodiments, including diverse processing phases and an apparatus for performing those processing phases, it should be understood that the invention is not limited thereto. Numerous modifications may be made to the invention without departing from the spirit and scope thereof. It is intended that all such modifications fall within the scope of the appended claims.



Claims
  • 1. An apparatus for processing material comprising:a chamber for containing the material, a rotatably driven shaft extending within the chamber to which is attached at least one element which engages the material in the chamber during rotation thereof, a drive mechanism for rotating the rotatably driven shaft, at least one of a heat source thermally coupled to the chamber for adding heat to the chamber and a vacuum source also coupled to the chamber for applying a vacuum to the chamber with the at least one source driving off liquid present in the chamber and a control for controlling the drive mechanism and the at least one source and wherein: the control controls the at least one source during rotation in first and second directions and the drive mechanism to rotate the driven shaft in a first direction to cause the at least one element to engage the material, in a fluid state, while the chamber is partially filled with the material through an angular rotation which lifts the material upward beyond a level of the material in the chamber without reaching a position which is directly above the driven shaft while the at least one source drives off liquid in the material and the control controls the drive mechanism to rotate the driven shaft in a second direction, opposite to the first direction, to cause the at least one element to engage the material, in a fluid state, through an angular rotation which lifts the material beyond the level of the material in the chamber without reaching a position which is directly above the driven shaft while the at least one source drives off liquid in the material; and after rotation of the driven shaft in the first and second directions the control controls the drive mechanism to rotate the driven shaft in one direction and the at least one source to drive off the liquid to produce dried material during the rotation in the one direction.
  • 2. An apparatus in accordance with claim 1 wherein:the control controls the drive mechanism to rotate the driven shaft in the first and second directions while the material is sufficiently viscous that the material would stick to the driven shaft if the material were to contact the drive shaft.
  • 3. An apparatus in accordance with claim 2 wherein:the control controls the drive mechanism to rotate the driven shaft through a plurality of sequential cycles with each cycle including rotation in the first and second directions.
  • 4. An apparatus in accordance with claim 3 wherein:the control controls the drive mechanism to rotate the driven shaft in one direction to cause the material to increase in viscosity prior to controlling the drive mechanism to rotate the driven shaft in the first and second directions; and after completion of rotating of the driven shaft in the first and second directions, the control controls the drive mechanism to rotate the driven shaft in one direction to particularize the material.
  • 5. An apparatus in accordance with claim 4 wherein the drive mechanism comprises:a first prime mover, which is controlled by the control, which rotates the driven shaft in the one direction; and a second prime mover, which is controlled by the control, which rotates the driven shaft in the first and second directions.
  • 6. An apparatus in accordance with claim 5 further comprising:the vacuum source, coupled to the chamber, applies vacuum to the chamber to drive off liquid present in the material.
  • 7. An apparatus in accordance with claim 4 wherein:the heat source adds heat to the material during the rotations of the driven shaft in the one direction and during the rotation of the driven shaft in the first and the second directions.
  • 8. An apparatus in accordance with claim 2 wherein:the control controls the drive mechanism to rotate the driven shaft in one direction to cause the material to increase in viscosity prior to controlling the drive mechanism to rotate the driven shaft in the first and second directions; and after completion of rotating of the driven shaft in the first and second directions, the control controls the drive mechanism to rotate the driven shaft in one direction to particularize the material.
  • 9. An apparatus in accordance with claim 8 wherein the drive mechanism comprises:a first prime mover, which is controlled by the control, which rotates the driven shaft in the one direction; and a second prime mover, which is controlled by the control, which rotate the driven shaft in the first and second directions.
  • 10. An apparatus in accordance with claim 9 further comprising:the vacuum source, coupled to the chamber, applies vacuum to the chamber to drive off liquid present in the material.
  • 11. An apparatus in accordance with claim 8 wherein:the heat source adds heat to the material during the rotations of the driven shaft in the one direction and during the rotation of the driven shaft in the first and the second directions.
  • 12. An apparatus in accordance with claim 3 wherein:the heat source adds heat to the material during rotation of the driven shaft through the plurality of sequential cycles to drive off liquid present in the material.
  • 13. An apparatus in accordance with claim 3 further comprising:the vacuum source, coupled to the chamber, applies vacuum to the chamber to drive off liquid present in the material.
  • 14. An apparatus in accordance with claim 2 wherein:the heat source adds heat being added to the material during controlling rotation of the driven shaft in the first and the second directions to drive of f liquid present in the material.
  • 15. An apparatus in accordance with claim 2 further comprising:the vacuum source, coupled to the chamber, applies vacuum to the chamber to drive off liquid present in the material.
  • 16. An apparatus in accordance with claim 1 wherein:the control controls the drive mechanism to rotate the driven shaft through a plurality of sequential cycles with each cycle including rotation in the first and second directions.
  • 17. An apparatus in accordance with claim 16 wherein:the control controls the drive mechanism to rotate the driven shaft in one direction to cause the material to increase in viscosity prior to controlling the drive mechanism to rotate the driven shaft in the first and second directions; and after completion of rotating of the driven shaft in the first and second directions, the control controls the drive mechanism to rotate the driven shaft in one direction to particularize the material.
  • 18. An apparatus in accordance with claim 17 wherein the drive mechanism comprises:a first prime mover, which is controlled by the control, which rotates the driven shaft in the one direction; and a second prime mover, which is controlled by the control, which rotates the driven shaft in the first and second directions.
  • 19. An apparatus in accordance with claim 18 further comprising:the vacuum source, coupled to the chamber, applies vacuum to the chamber to drive off liquid present in the material.
  • 20. An apparatus in accordance with claim 17 wherein:the heat source adds heat to the material during the rotations of the driven shaft in the one direction and during the rotation of the driven shaft in the first and the second directions.
  • 21. An apparatus in accordance with claim 14 wherein:the heat source adds heat to the material during rotation of the driven shaft through the plurality of sequential cycles to drive off liquid present in the material.
  • 22. An apparatus in accordance with claim 16 further comprising:the vacuum source, coupled to the chamber, applies vacuum to the chamber to drive off liquid present in the material.
  • 23. An apparatus in accordance with claim 1 wherein:the control controls the drive mechanism to rotate the driven shaft in one direction to cause the material to increase in viscosity during the rotation in one direction prior to controlling the drive mechanism to rotate the driven shaft in the first and second directions; and after completion of rotating of the driven shaft in the first and second directions, the control controls the drive mechanism to rotate the driven shaft in one direction to particularize the material.
  • 24. An apparatus in accordance with claim 23 wherein the drive mechanism comprises:a first prime mover, which is controlled by the control, which rotates the driven shaft in the one direction; and a second prime mover, which is controlled by the control, which rotates the driven shaft in the first and second directions.
  • 25. An apparatus in accordance with claim 24 further comprising:the vacuum source, coupled to the chamber, applies vacuum to the chamber to drive off liquid present in the material.
  • 26. An apparatus in accordance with claim 23 wherein:the heat source adds heat to the material during the rotations of the driven shaft in the one direction and during the rotation of the driven shaft in the first and the second directions to drive off liquid present in the material.
  • 27. An apparatus in accordance with claim 1 wherein:the heat source adds heat to the material during rotation of the driven shaft in the first and the second directions to drive off liquid present in the material.
  • 28. An apparatus in accordance with claim 1 wherein:the at least one element is spaced from a wall of the chamber.
  • 29. An apparatus in accordance with claim 1 further comprising:the vacuum source, coupled to the chamber, applies vacuum to the chamber to drive off liquid present in the material.
  • 30. An apparatus for processing material comprising:a chamber for containing the material, a rotatably driven shaft extending within the chamber to which is attached at least one element which engages the material in the chamber during rotation thereof, a drive mechanism for rotating the rotatably driven shaft, at least one of a heat source thermally coupled to the chamber for adding heat to the chamber and a vacuum source also coupled to the chamber for applying a vacuum to the chamber with the at least one source driving off liquid present in the chamber and a control means for controlling the drive mechanism and the at least one source and wherein: the control means controls the at least one source during rotation in first and second directions and the drive mechanism to rotate the driven shaft in a first direction to cause the at least one element to engage the material, in a fluid state, while the chamber is partially filled with the material through an angular rotation which lifts the material upward beyond a level of the material in the chamber without reaching a position which is directly above the driven shaft while the at least one source drives off liquid in the material and the control means controls the drive mechanism to rotate the driven shaft in a second direction, opposite to the first direction, to cause the at least one element to engage the material, in a fluid state, through an angular rotation which lifts the material beyond the level of the material in the chamber without reaching a position which is directly above the driven shaft while the at least one source drives off liquid in the material; and after rotation of the driven shaft in the first and second directions, the control means controls the drive mechanism to rotate the driven shaft in one direction and the at least one source to drive off the liquid to produce dried material during the rotation in the one direction.
US Referenced Citations (26)
Number Name Date Kind
2173715 Geldhof Sep 1939
2411138 Roberts Nov 1946
2650807 Bilek Sep 1953
3318668 Ziehl May 1967
3484204 Caviness Dec 1969
3650319 Boon Mar 1972
3845642 Cochran Nov 1974
4010932 Otto Mar 1977
4176966 Bornemann Dec 1979
4187992 Del Valle Feb 1980
4229109 Benson Oct 1980
4274751 Rector et al. Jun 1981
4473001 Rieger Sep 1984
4548054 Levine Oct 1985
4676654 Fleckner Jun 1987
4705222 Shohet Nov 1987
4836686 Sukup Jun 1989
4893943 McKelvey Jan 1990
5139667 Reneau, Jr. Aug 1992
5261746 Boasso Nov 1993
5275484 Shohet Jan 1994
5297454 Ito Mar 1994
5645346 Thuna Jul 1997
5655389 Johnson et al. Aug 1997
5697703 Lucchetti Dec 1997
5720190 Johnson et al. Feb 1998