Fluid Charged Rotary Heating System

Abstract

A fluid-charged heating device comprising a cylindrical housing in fluid communication with a housing extension; a cylindrical rotor disposed centrally and mounted for rotation in said cylindrical housing in spaced relation to provide an annular passage for heat transfer fluid to recirculate between the cylindrical housing and the housing extension. The rotor has a surface with a continuous helical groove along the longitudinal axis of the rotor and rotation of the helically grooved rotor causes fluid shearing, heat-generating cavitation, and recirculation of the heat transfer fluid between the housing and the housing extension.

Description

FIELD OF THE INVENTION

The present invention relates generally to rotary heating systems and devices wherein rotating cylindrical rotors are employed to generate heat in heat transfer fluids in contact therewith. Devices of this type can be usefully employed as heating systems in applications requiring hot water supply, for instance in the home, or by incorporation as a heat pump or heating element within a heating system adapted for residential and industrial use.

BACKGROUND OF THE INVENTION

Various designs exist for devices which use rotating members to increase pressure and/or temperature of fluids. U.S. Pat. No. 3,791,349 discloses an apparatus and method for production of steam and pressure by creating shock waves in a distended body of water. Various passageways and chambers are employed to create a tortuous path for the fluid and to maximize the water hammer effect. U.S. Pat. No. 3,720,372 also employs rotating members to heat fluids wherein a turbing type coolant pump driven by an automobile engine is used to warm engine coolant.

In U.S. Pat. No. 4,424,797, a rotating cylindrical rotor is disposed inside a static housing and fluid entering at one end of the housing navigates through the annular clearance existing between the rotor and the housing to exit the housing at the opposite end and relies principally on the shearing effect in the liquid, causing it to heat up.

U.S. Pat. No. 5,188,090 issued to Griggs also employs a rotating cylindrical rotor inside a static housing and fluid entering at one end of the housing navigates past the annular clearance existing between the rotor and the housing to exit the housing at the opposite end. The device of U.S. Pat. No. 5,188,090 employs a number of so-called surface irregularities on the cylindrical surface of the rotor. Unlike the fluid shearing effect of U.S. Pat. No. 4,424,797, the surface irregularities of the U.S. Pat. No. 5,188,090 rotor is alleged to produce hydrodynamically induced cavitation also known as the phenomena of water hammer in pipes. The surface irregularities of U.S. Pat. No. 5,188,090, at the beginning of rotor rotation, may be largely empty of fluid, and as such, there is likely a time lag before sufficient fluid is, by the severe turbulent flow conditions, in the gap between rotor and housing, able to enter into these surface irregularities to produce the desired hydrodynamically induced cavitational heating of the fluid flowing through the machine.

A further limitation of the Griggs device is that the maximum effect is limited by the size of volume pocket void that exists for each surface irregularity. For instance, a surface irregularity in the form of a drilled hole has a certain diameter and depth which determines the maximum quantity of fluid it can hold. During operation of the Griggs device, this quantity of fluid is most likely quite substantially reduced in order to create the desire effect of a very low-pressure region in and about the hole. For certain applications, there may be advantage through the deployment of deeper holes in the rotor, as compared to the depth of holes taught by Griggs, for improved shock wave transmissions from the cavitation implosion zones to maximum power efficiency in performance.

The Griggs system and its progeny are most notably adapted for a continuous flow system where water entering from an inlet is heated as it exits the rotary chamber. The present invention, on the other hand, is a thermodynamically efficient system operable as a fluid-charged closed heating device in which the rotation of a specially designed rotor within an annular housing produces both shearing and cavitational effect on the heat transfer fluid to improve on some or all of the above mentioned limitation of earlier machines without undue structural complication and whereby the cavitational heating of the fluid by shock wave transmissions from the cavitation implosion zones can be maximized.

SUMMARY OF THE INVENTION

Accordingly, this invention relates to a fluid-charged heating device comprising a cylindrical housing in fluid communication with a housing extension via connecting means; a cylindrical rotor disposed centrally and mounted for rotation in said cylindrical housing in spaced relation to provide an annular passage for heat transfer fluid to recirculate between said cylindrical housing and said housing extension; said rotor having a surface with a continuous helical groove along the longitudinal axis of the rotor, wherein rotation of said helically grooved rotor causes fluid shearing, heat-generating cavitation, and further causes recirculation of the heat transfer fluid between the housing and the housing extension.

It is thus an object of the invention to provide a fluid-charged heating device comprising a motor-driven cylindrical rotor whose cylindrical surface features a continuous helical groove. The rotor rotates within a housing whose interior surface conforms closely to the cylindrical surfaces of the rotor. A bearing plate, which serves to mount bearings and seals for the rotor, abuts each side of the housing. The bearing plates feature hollowed portions which communicate with the void between the housing and rotor. A housing extension is formed adjacent to or remote from both ends of the housing to allow recirculation of the heat transfer fluid via a pair of connecting means comprising a high temperature inlet means to the housing extension and a low temperature outlet means from the housing extension, the housing extension further or optionally comprising a heat dissipation means.

A fluid charging port is formed in the device, optionally near the housing extension to allow for fluid charging and maintenance. The housing and housing extensions are optionally provided with integral heat exchange elements such as plates and fins welded on the housing and/or housing elements to allow for heat exchange with the ambient mass. The rotor is most preferably mounted on a shaft which may be driven by electric motor or other motive means, and may be driven directly, geared, powered by pulley or otherwise driven.

According to one aspect of the present invention, heat transfer fluid located between a rotating rotor and stationary housing is heated in a re-circulating fashion in a device which is structurally simple and requires reduced manufacturing and maintenance costs, wherein heat contained in the heat transfer fluid is exchanged with mass in contact with the housing and/or the housing extension.

It is one object of the present invention to produce a mechanically elegant and thermodynamically highly efficient fluid-charged heating device for increasing pressure and/or temperature of a heat transfer fluid in a closed system comprising mechanically or electrically driven rotor(s) whose surface is provided with continuous helical groove, said groove being also sized and configured to propel the fluid radially outwards in a generally spiral path, until redirected by the interior shape and pressure differences in the housing and housing extensions thereby causing re-circulation of the heat transfer fluid; said rotor rotating in a cylindrical housing closely conforming to the diameter of the rotor.

It is another object of the present invention to provide a new and improved mechanical heat generator or heating element, capable of producing heat at a high yield with reference to the energy input comprising a cylindrical rotor having a continuous helical groove caused to rotate in a cylindrical housing in close conformity to the rotor and causing recirculation of a heat transfer fluid between the rotor housing and a housing extension. The re-circulating fluid while in the annular space between the rotor and housing is heated, firstly by the shearing effect on the fluid between static and dynamic opposing boundary surfaces, and secondly from the deployment cavitation inducing helical groove on the exterior surface of the rotor, said helical groove sized and configured to also cause recirculation of the heat transfer fluid between the rotor housing and a housing extension wherein said housing extension optionally comprises a heat exchanger or heat dissipation means.

It is yet another object of the present invention to provide a new and improved method of heat generation, capable of producing heat at a high yield with reference to the energy input comprising the steps of causing a cylindrical rotor having a surface provided with a continuous helical groove to rotate in a cylindrical rotor housing in close conformity to the diameter of the rotor and causing recirculation of a heat transfer fluid between the rotor housing and a housing extension wherein said fluid in said rotor housing is heated by fluid shearing between static and dynamic opposing boundary surfaces and by heat-generating cavitation inducing helical groove on the exterior surface of the rotor, and wherein the heat transfer fluid is continuously re-circulated between the rotor housing and the housing extension; said housing extension optionally comprising a heat dissipation means.

Although this invention is capable of being used in the Griggs format for heating of a liquid in continuous ingress and egress through the rotor-induced shearing zone, the preferred arrangement of the present invention is a recirculating fluid charged closed system in which a helically grooved rotor disposed centrally in a housing and mounted for rotation within the housing about an axis of rotation, is spaced relative to the housing to provide a generally annular passage for heat transfer fluid to re-circulate between the housing and the housing extension.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the invention as claimed. Other objects and features of the invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. The accompanying drawings are included solely for purposes of illustration and not as a definition of the limits of the invention. Also, the drawings are not drawn to scale, and are merely conceptual in disclosing the preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, wherein like reference numerals identify similar elements:

FIG. 1 is a schematic view of a single rotor heating device according to one embodiment of the present invention.

FIG. 2 is a schematic view of a dual rotor heating device according to one embodiment of the present invention.

FIG. 3 is a schematic view of a triple rotor heating device according to one embodiment of the present invention.

FIG. 4 is a cut-away view of a single rotor heating device according to one embodiment of the present invention showing a shaft mounted motor-driven rotor and a housing extension.

FIG. 5 is a cut away view of the rotor showing the helical grooves, the annular channel and the stationary housing.

FIG. 6 is a fluid-charged embodiment of FIGS. 1 and 4.

FIG. 7 is a schematic view of the hydrodynamic profile of fluid-charged embodiment of FIGS. 1 and 4 in the presence of a rotating rotor.

FIG. 8 is a schematic of the dual rotor device according to one embodiment of the present invention with heat transfer elements integrally or adjacently attached to the housing and housing extensions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE PRESENT INVENTION

Referring now to the drawings of the present disclosure in which like numbers represent the same structure in the various views,

As shown in FIGS. 1-4, device 10 comprises a rotor 12 mounted on a shaft 14, which rotor 12 rotates within a housing 30 in a recirculating inlet and outlet communication with a housing extension 36 via connecting means 34. Shaft 14 in the embodiment shown in FIG. 4 has a primary diameter of ¼″ and may be formed of forged steel, cast or ductile iron, or other materials as desired. Shaft 14 is designed for rigid interference fit with the shaft bore 18 on the rotor 12. (See FIG. 7). Shaft 14 may be driven by an electric motor 20 or other motive means, and may be driven directly, geared, driven by pulley 26, or driven as otherwise desired. In one embodiment, locking pins, set screws or other fasteners may be used to fix rotor 12 with respect to shaft 14. As used in this specification, shaft 14 encompasses any mechanically suitable connecting means for rigidly coupling the rotor 12 to the drive motor 20.

Attached rigidly to shaft 14 is rotor 12. Rotor 12 may be formed of aluminum, steel, iron or other metal or alloy as appropriate. Rotor 12 is essentially a solid cylinder of material featuring a shaft bore 18 to receive shaft 14, having a continuously running helical groove 16 on its cylindrical surface 24. In the embodiment shown in FIGS. 4 and 5, rotor 12 is one inch in diameter and twenty four inches in length. It is understood that the dimensions of the rotor 12 are scalable to accommodate the heat generating capacity of the desired application.

In the embodiment shown in FIGS. 5 to 8, the helical groove measures ⅛ inch wide and 1/16 inch deep and runs preferably three quarters of the length of the rotor as illustrated in FIG. 8. The depth, diameter and orientation of the helical groove 16 may be adjusted in dimension to optimize efficiency and effectiveness of device 10 for heating various fluids, and to optimize operation, efficiency, and effectiveness of device 10 with respect to particular fluid temperatures, pressures and flow rates, as they relate to rotational speed of rotor 12; the grooves being sized and configured to also cause re-circulation of the heat transfer fluid from the housing 36, through connecting means 34, via a housing extension or heat dissipation means 36. In a preferred embodiment of the device 10, the rod rotates at least 3450 rpm.

In the embodiment shown in FIGS. 5-8, the annular space 50 between the rotor 12 and the housing 30 is minimally sufficient to avoid contact between the rotor 12 and the housing 30 and is of the order of thousandths of an inch, preferably about 2-3 thousandths of an inch. Smaller or larger clearances may obviously be provided, once again depending upon the parameters of the fluid involved, the desired flow rate and the rotational speed of rotor 12. The housing 30 is connected to a housing extension 36 via connecting means 34 optionally having an elbow 32. The housing 30, connecting means 34 and housing extensions 36 may be formed of aluminum, stainless steel or otherwise as desired, and preferably feature a removable cap or plug 38 through which the heating device is charged with the heat transfer fluid or other wise for maintenance of the system. The plug 38 may optionally comprise a pressure relieve valve (not shown). The housing extension may simply be a fluid holding tank or reservoir. However, as used in this specification, the housing extension 36 preferably comprises any suitable means for dissipating the heat generated in the rotor housing 30 wherein the connector pair 34 respectively comprise high temperature fluid inlet and low temperature fluid outlet to and from the dissipating means 36.

The interior surface 40 of the housing 30 may be smooth with no irregularities, or may be serrated, feature holes or helical grooves running counter to the grooves 16 of the shaft 12, as desired to increase efficiency and effectiveness of device 10 for particular fluids, flow rates and rotor 12 rotational speeds. In the preferred embodiment, the interior surface 40 is smooth.

Connected to the ends of the housing 30 is a bearing plate 60A and 60B. See for example FIG. 6. The primary function of bearing plates 60A and 60B is to carry one or more bearings 62 (roller, ball, or as otherwise desired) which in turn carry rotor 12, and to carry an O-ring 66 preferably made of tungsten carbide that contacts the rotor in sliding relationship to the bearing plate 60A and 60 B which is attached to the housing 30 via a mechanical sealing means 64. The sealing means 64 acting in combination with the O-ring 66 prevent leakage of fluid adjacent to rotor 12 from the device 10. Mechanical sealing means 64 is preferably spring-loaded. Sealing means 64 may typically be a rotary lip seal or double lip seal capable of working under pressure as well as under negative pressure conditions, although it should be noted all embodiments may easily be adapted to incorporate other types of seals that are readily available. For instance, a spring-loaded face seal could be used operating against the end face of the rotor. One or more bearings may be used with each bearing plate 60A and 60B to carry rotor 12. The bearings are preferably self-lubricating.

Bearing plates 60A and 60B may be fastened to the housing 30 using bolts 70 or as otherwise desired. Preferably disk-shaped retainer plates through which rotor 12 extends may be used to retain bearings 62 in place.

The heat transfer fluid which is introduced into the system via the charging cap 38 circulates through the annular space 50 and the connecting means 34 and the housing extensions 36 in a direction counter to the direction of rotation of the rotor 12 within the housing 30. The fluid is drawn into and through the space 50 between rotor 12 and housing 30, where rotation of rotor 12 comprising the helical grooves 16, with respect to interior surface 40 of housing 30 imparts heat to the fluid.

FIGS. 2, 3, and 8 illustrate one embodiment of the device in which a plurality of rotors 12A, 12B, 12C are rotated by a single motor 20 via pulleys 26 in separate cylindrical housing units 30A, 30B, 30C in recirculating and thermodynamic connection to a common housing extension 36. Additionally, appropriate heat transfer elements 100 (See FIG. 8) adjacent to the housing and housing extensions may be used effect heat transfer from the heat transfer fluid to the surrounding mass.

It is also to be understood that the housing extension 36 can comprise a remotely disposed heat dissipating means such as a heater core, a radiator, or a heat exchange system for dissipating heat energy generated in the housing 30 and carried by the re-circulating heat transfer fluid. In one embodiment, the pair of connecting means 34 communicating the recirculating heat transfer fluid between the rotor housing 30 and the housing extension 36, comprise a tubular inlet port receiving high temperature fluid from the housing 30, and a tubular outlet port directing low temperature fluid to the housing via the heat dissipating means or housing extension 36. In one embodiment, the heat dissipating means comprises a plurality of flow tubes or tubular plates in fluid communication with the inlet and outlet connector pair 34. Means reasonably adapted to optimize the operation of the heat dissipating means are encompassed by this disclosure. U.S. Pat. No. 5,186,249, which is herein incorporated by reference relates to one method of ensuring uniformity fluid flow rates in the plurality of flow tubes within the heat dissipating means.

In another embodiment, the heat dissipating means or housing extension 36 comprise a plurality of plates and a plurality of fins extend between and may be secured to each adjacent pair of plates. The fins may be secured to the plates by brazing, welding, diffusion bonding etc. Alternatively the fins may not be secured to the plates. The fins are defined by corrugated plates. In plate fin heat exchangers the fins define the passages for the flow of fluids to be put into heat exchange relationship, said fluid communicating with the pair of connecting means 34 carrying high temperature fluid away from the housing 30 and returning low temperature fluid to the rotor housing 30.

In another embodiment, the heat dissipating means 36 comprise a plurality of plates and a plurality of spacers extend between each adjacent pair of plates to separate the plates wherein the plates define passages for the flow of re-circulating fluid to be put into heat exchange relationship with ambient mass.

Heat transfer fluids of the present invention ideally should be operable at a broad range of temperatures, have low viscosities to minimize pumping problems at low temperatures and provide an acceptable rate of heat transfer, have a sufficiently low freezing point, decompose only at slow rates in use, and resist the formation of degradation products that foul the systems in which they are used. Moreover, for convenient handling, clean up and disposal, it is desirable that they be environmentally non-hazardous and of low toxicity.

Density, thermal conductivity, specific heat and kinematic viscosity are specific parameters that describe the performance of a heat transfer medium. Other factors such as environmental impact, toxicity, flammability, and corrosive nature can also affect the feasibility and performance of a heat transfer medium. Furthermore, the freezing and boiling points, and thermal and oxidative stability of the heat transfer fluids, restrict the operational temperature range of the heat transfer processes in which they are used.

Several classes of heat transfer fluid compositions are well known and utilized commercially, all of which satisfy at least some of the criteria listed above. Examples of some of these are petroleum oils, synthetic aromatic compounds such as alkylated aromatics, phenylene oxides and diphenylene oxides, terphenyls, phenoxybiphenyls and phenoxyterphenyls, polyalkylene ether glycol type copolymers of ethylene oxide and propylene oxide, and polydimethylsiloxane based silicone fluids.

In preferred embodiments, the heat transfer fluid also comprises at least one additive selected from the group consisting of antioxidants, corrosion inhibitors, thermal stabilizers, viscosity modifiers and anti-foaming agents.

In another embodiment, the heat transfer fluid may be blended with component selected from the group consisting of ethylene glycol, diethylene glycol, polyalkylene glycol copolymers of ethylene oxide and propylene oxide, aromatic compounds selected from the group consisting of biphenyl and polyphenyl ethers, vegetable oils, mineral oil, silicone fluids, and mixtures thereof.

In a preferred embodiment, the heat transfer fluid comprises (a) from about 50 wt. % to 99 wt. % 30,000 CST polydimethylsiloxane based silicone fluid and (b) from about 1 wt. % to about 50 wt. % of 60,000 CST polydimethylsiloxane silicone fluid as blending component.

It will be apparent to those skilled in the art that the operation of the heating system comprising the various embodiments of the present invention can be easily controlled through feedback of a temperature sensor using a controller configured to control the rotation of the rotor 12 via the drive motor 20.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. Accordingly, the invention is not limited by the embodiments described above which are presented as examples only but can be modified in various ways within the scope of protection defined by the appended patent claims. All the references cited in this specification are herein incorporated by reference in their entireties.

Claims

1. A fluid-charged heating device comprising a cylindrical housing in fluid communication with a housing extension via connecting means; a cylindrical rotor disposed centrally and mounted for rotation in said cylindrical housing in spaced relation to provide an annular passage for heat transfer fluid to recirculate between said cylindrical housing and said housing extension; said rotor having a surface with a continuous helical groove along the longitudinal axis of the rotor, wherein rotation of said helically grooved rotor causes fluid shearing, heat-generating cavitation, and further causes recirculation of the heat transfer fluid between the cylindrical housing and the housing extension.

2. The fluid-charged heating device of claim 1, wherein said housing and housing extension further comprise heat transfer elements adjacent thereto to transfer heat from the heat transfer fluid to surrounding mass.

3. The fluid-charged heating device of claim 2, wherein the heat transfer elements comprise plates or fins welded on the housing and/or housing extension.

4. The fluid-charged heating device of claim 1, wherein said housing extension further comprises a heat dissipation means in fluid communication with the cylindrical housing via a tubular inlet port receiving high temperature fluid from the housing, and a tubular outlet port directing low temperature fluid to the housing.

5. The fluid-charged heating device of claim 4, wherein the heat dissipating means comprises a plurality of flow tubes or tubular plates in fluid communication with the connecting means.

6. The fluid-charged heating device of claim 4, wherein the heat dissipating means comprises a plate fin heat exchangers wherein the fins define passages for flow of fluids to be put into heat exchange relationship with the ambient mass, wherein said fin passages are in fluid communication with the connecting means.

7. The fluid-charged heating device of claim 4, wherein the heat dissipating means comprise a plurality of plates and a plurality of spacers extend between each adjacent pair of plates to separate the plates wherein the plates define passages in fluid communication with the connecting means, for the flow of re-circulating fluid to be put into heat exchange relationship with ambient mass.

8. The fluid-charged heating device of claim 1, wherein the heat transfer fluid is at least one selected from the group consisting of petroleum oils, alkylated aromatics, phenylene oxides, diphenylene oxides, terphenyls, phenoxybiphenyls, phenoxyterphenyls, polyalkylene ether glycol type copolymers of ethylene oxide and propylene oxide, and polydimethylsiloxane based silicone fluids.

9. The fluid-charged heating device of claim 8, wherein the heat transfer fluid further comprises at least one additive selected from the group consisting of antioxidants, corrosion inhibitors, thermal stabilizers, viscosity modifiers and anti-foaming agents.

10. The fluid-charged heating device of claim 8, wherein the heat transfer fluid is blended with components selected from the group consisting of ethylene glycol, diethylene glycol, polyalkylene glycol copolymers of ethylene oxide, propylene oxide, biphenyl ethers, polyphenyl ethers, vegetable oils, mineral oil, and silicone fluids.

11. The fluid-charged heating device of claim 8, wherein the heat transfer fluid comprises (a) from about 50 wt. % to 99 wt. % 30,000 CST polydimethylsiloxane based silicone fluid and (b) from about 1 wt. % to about 50 wt. % of 60,000 CST polydimethylsiloxane silicone fluid as blending component.

12. A fluid-charged heating device comprising a plurality of cylindrical housings in fluid communication with a common housing extension via connecting means; a plurality of cylindrical rotors disposed centrally and mounted for rotation in their respective cylindrical housing in spaced relation to provide an annular passage for heat transfer fluid to recirculate between said plurality of cylindrical housing and said common housing extension via said connecting means; each of said plurality of rotors having a surface with a continuous helical groove along the longitudinal axis of the rotor, wherein rotation of said helically grooved rotors causes fluid shearing, heat-generating cavitation, and further causes recirculation of the heat transfer fluid in said cylindrical housings between the housings and the housing extension.

13. A method of heat generation comprising the steps of causing a cylindrical rotor having a surface provided with a continuous helical groove to rotate in a cylindrical rotor housing in close conformity to the diameter of the rotor and causing recirculation of a heat transfer fluid between the rotor housing and a housing extension wherein said fluid in said rotor housing is heated by fluid shearing and heat-generating cavitation and said fluid continuously re-circulated between the rotor housing and the housing extension; said housing extension optionally comprising a heat dissipation means.