Patent Application
20150192314
At the present time there is a significant benefit to end users in reducing the use of electricity during periods of high demand, when electric rates are at their highest level. Numerous systems are currently being employed for this purpose. Some of these involve the use of ice, in which ice is generated during the night, when electric rates are low, and consumed during times of peak rates to improve the efficiency and reduce the electric usage of refrigeration and air conditioning systems. The scale of these systems varies dramatically. Some are for use by very small entities, such as a small commercial building, while others are on a very large scale. The proposed invention, in its various embodiments, could be scaled to a wide range of sizes.
This invention is a machine which quickly and efficiently makes ice, stores the ice, and when needed quickly and efficiently consumes the ice to provide a heat-sink for refrigeration or air conditioning use, or for other purposes. The invention, in various embodiments, generates ice in a manner which has very high heat transfer rates and high efficiency, stores the ice until needed, and then, using the same surface which generated the ice, consumes the ice as a heat sink for refrigeration or air conditioning systems or for other purposes, again with very high heat transfer rates and high efficiency.
All prior patents related to the proposed invention have extruded ice from a conical or pyramidal cell, which ice was removed from the cell for use elsewhere. In particular, U.S. Pat. No. 2,671,465 describes the basic mechanism of such a device, and U.S. Pat. No. 2,639,594 describes a machine which operated successfully. Both of these patents apply only to the production of ice to be used away from the machine, both apply only to the use of a generating surface in the form of the interior of a cone or pyramid, and both rely on the linear action of a specific type of ram to force the ice block away from the refrigerated surface.
Throughout this narrative and the claims, the surface referred to as the “generating surface” or the “ice generating surface” both freezes and melts the ice, depending on need. The term “refrigerant” is herein used to mean a heat transfer fluid, such as Freon, and which may be cooling or heating the generating surface depending on whether the machine is making ice or melting ice.
The descriptions and illustrations which follow refer in general to machines which generate ice in vertical configurations. Many of these machines could be made to generate ice in a horizontal configuration, by making various obvious modifications to the designs.
The drawings and explanations contained herein should be considered to be illustrative and should not be construed so as to in any way limit the claims made. In particular, the methods of rotation and linear action of the generating surface and the ram can be achieved in various ways not shown. The term pyramid or pyramidal as used here should be taken to refer to a pyramid with a base which is a square, rectangle or other polygon. The size of the ram has been exaggerated in the drawings for purposes of clarity.
The novel elements supporting this invention are 1) a number of different designs for the rapid and efficient production of solid ice by a refrigerated generating surface, 2) use of the same surface which makes the ice to rapidly and efficiently consume the ice as a heat sink for refrigeration, air conditioning or other use, 3) the efficient combining these two functions by storing the ice where it has been generated, and 4) the design of the ram used in certain embodiments of the invention. The use of these elements in a single machine is the basis for Claims 1 through 22.
Ice which is generated by contact with a cold surface generally forms a sufficiently strong bond with the cold surface that if the ice and the surface are pulled apart in tension the bonds within the ice may rupture preferentially to the bonds between the ice and the cold surface, leaving significant amounts of ice bonded to the cold surface. Successful extrusion of ice depends upon separating the ice from the cold surface at a shallow angle. If the angle of separation is sufficiently small, shearing forces predominate over tensile forces, and the ice separates cleanly, leaving a gap. If this gap is small, and is immediately filled with water, the water will freeze quickly on contact with the refrigerated surface, and the process can be repeated. It has been demonstrated that a machine of this type can produce ice at a rate of 130 kg of ice per square meter of freezing surface per hour.
In all of the following designs the expansion which takes place when water freezes is accommodated at the freezing surface, and does not generate pressure on the walls of the containing vessel.
The machines described herein make a solid block of ice, either by repetitively moving the ice block away from a stationary generating surface or by moving the generating surface away from the stationary ice block. When an ice block of the desired volume has been made, it is stored in situ until needed for cooling.
In some of the following embodiments the vessel which stores the ice also contains the water used in the system. This has the advantage that a separate storage tank is avoided. Also, this arrangement permits the making of ice above the stored water, as the buoyancy of the ice will hold it in the top of the vessel. In order to prevent freezing of the stored water, the stored water is maintained at a temperature slightly above 0° C. This has the additional advantage that all of the stored water is at the ideal temperature to be introduced at the ice generating surface.
In all embodiments in which the water and ice block are contained within the same vessel, an auxiliary storage tank will be required to accommodate a portion of the stored water as it is forced out of the vessel due to expansion of the ice as it freezes.
To consume the ice, the flow of refrigerant through the system is reversed, so that the ice block serves as a heat sink for air conditioning or refrigeration. In this mode, warm refrigerant is circulated through the generating surface, consuming the ice which is in contact with it. The ice and the generating surface are forced together, producing very rapid heat transfer into the ice. When all of the ice has been consumed, the machine is ready to generate ice again. In many of the embodiments herein, consumption of the ice block can be expedited by constructing the containing vessel so that refrigerant can also be circulated through the walls of the vessel during the consumption phase of the cycle.
In some of the following embodiments, to promote consumption it is necessary to provide a means by which the ice block is forced against the warm generating surface. In these cases a rigid plate is provided which is maintained in contact with the ice block. During ice production, force is applied to this plate only in those embodiments in which the ice block might float, and in that case only sufficient force is applied to offset the buoyancy of the ice block. During ice consumption a ram forces the plate against the ice block, which force maintains the ice block in intimate contact with the warm generating surface.
In some of the following embodiments, the vessel or tank in which the ice is made also holds the water supply for the system. In all of these cases the water circulates in the area of the ice blocks. A key advantage of this feature is that during the consumption phase of the cycle this water may be circulated through a heat exchanger in order to accelerate the rate of consumption.
Certain of the embodiments of this invention employ a generating surface which moves in incremental steps of a few millimeters through a water-filled or air-filled vessel of cylindrical or prismatic shape, leaving behind it a block of solid ice. This concept of ice generation is novel, and is the basis for Claim 2. The generating surfaces in the following embodiments are designed in such a way that when the generating surface is withdrawn, shear forces predominate over tensile forces so that the generating surface is cleaned of residual ice, and can thus quickly generate a new layer of ice in the small gap left by the withdrawal of the generating surface. In all of these embodiments the water which is to be introduced into contact with the freezing surface is maintained at a temperature close to 0° C. so that it will freeze quickly.
In these embodiments, the moving generating surface also serves to consume the ice when the machine is in the ice consumption mode, by forcing the warm generating surface against the ice block.
In some of these embodiments, a portion of the ice block is permanent. The surfaces of the vessel surrounding the permanent ice block are refrigerated, and the sides of the vessel and attachments to it are made in such manner that this permanent ice block is restrained from moving.
The following are descriptions of specific embodiments with incrementally moving generating surfaces.
D.1 Incrementally Moving Generating Surface in the Form of the Exterior of a Cone, with Optional Rotation of the Generating Surface
Prior to making ice, the piston is in the position shown, and the entire drum is filled with water. To initiate operation, the chamber above the piston is refrigerated by the refrigerant lines and by cooling the conical surface. Expansion of the freezing ice is accommodated by water passing through the annular space between the piston and the drum, and by allowing the piston to move downward. Once made, the ice block is maintained at a few degrees below 0° C. This block is never again consumed.
For making ice, the temperature of the generating surface is maintained below 0° C. The piston is moved downward a few millimeters, and rotated if necessary for proper separation. Note that horizontal corrugations in the drum and the shape of the ice block keep the surface of the ice in compression as the piston is withdrawn. The ice shears from the cone, creating a gap which is simultaneously filled with water from below the piston. Since the water forms a thin layer against the cooled generating surface, the water freezes very quickly. Once the this new layer is frozen, the temperature sensors on the cooling surface record a quick drop in temperature, signaling to the system controls that the piston may be dropped again, initiating a new freezing cycle. In practice, if the operating parameters are maintained constant, the cycle can be timer controlled at a constant rate, with no need for sensors. The cycle rate, and thus the rate of ice production, can be increased by lowering the temperature of the refrigerant.
The advantages of a conical surface over a flat surface are 1) a conical surface, depending on the angle of the cone, can be withdrawn from the ice surface without the need for rotation, 2) the lateral area of a cone is always greater than the area of its base, so the rate of ice production is greater than for a flat surface. If rotation is required, the rotation of the piston alternates from clockwise to counterclockwise in each consecutive action. This simplifies the design of the machine, and simplifies the design of the refrigerant lines feeding the generating surface.
A generating surface which achieves separation by simultaneous rotation and withdrawal makes possible the use of a cone shape with a very low angle or of a flat circular plate. In this case it may be necessary to provide a small heated section or a small conical projection at the center of the cone or flat circular plate, to assist in separation.
In some instances it may be desirable to hold the water in a separate tank. In this case a configuration which is inverted from the position shown may be more advantageous. In the inverted configuration a small amount of water is maintained above the piston, so as to automatically fill the gap created by the generating surface as it withdraws.
In a variation of this design the ice block is at the bottom of an air-filled column, with the generating surface facing downward, and moving upward to make ice and downward to melt the ice.
In this embodiment the ice generating surface is a flat plate which breaks its bond with the ice block by moving less than one centimeter to the side, and simultaneously withdrawing a few millimeters, allowing water to enter the gap created. In the next movement, the generating surface moves in the opposite direction. The general configuration of this embodiment is similar to that shown in
In these embodiments the ice generating surface is the interior of a stationary truncated cone fixed at the top or bottom of a vertical cylinder, with a refrigerated ram at the tip of the cone. The ice produced is pushed away from the generating surface into an insulated cylinder, where it is stored until needed. The novel elements in this machine consist of 1) storage of the ice as it is produced, in a vertical cylinder above or below the ice generating surface, 2) consumption of the ice using the same generating surface, and 3) the use of a flat ram or a flat ram with a conical projection at its center, which both rotates and moves linearly. Rotation of the ram allows it to more easily detach itself from the ice block than a ram which merely retracts, as in the prior art. Further, this ease of detachment from the ice block allows the ram itself to be refrigerated, which accelerates the overall freezing rate. This embodiment is the basis for Claim 8. This embodiment is shown in
To initiate the operation of the machine a block of ice is allowed to form, filling the volume above the cone. Then 1) the ram rotates a few degrees, to break the bond between the ram and the ice block, 2) the ram pushes the block of ice away from the generating surface, forming a gap between the ice and the ice generating surface, 3) the gap between the ice and the ice generating surface fills with water, 4) the ram rotates and retracts, detaching itself from the ice block, 5) additional water enters from the base of the cone, to fill the gap left by the retracting ram, 6) the water in the gap freezes, and the cycle is repeated until the desired quantity of ice has been generated. As shown in
The following embodiments envision storage of the water above or below the ice block. In these embodiments, if the open face of the generating surface is at the bottom of the machine and faces upward, then the water is stored above the ice, with an insulating blanket between the ice and the water. If the generating surface is at the top of the machine and faces downward, then the water is stored below the ice, also with an insulating blanket between the ice and the water. The advantages of these arrangements are 1) that separate storage for the water is not necessary, 2) that all of the water and ice are within the same insulated vessel, and 3) that a small amount of pressure on the water will hold the ice block against the surface of the ice generating surface, both during ice generation and consumption. A small amount of leakage between the water and the ice is not a problem, as the leakage will adhere to the ice block or drain into the water supply area for the ice generating surface. In the case in which the ice generating surface is at the top of the machine, a small pump may be necessary to maintain sufficient water pressure to assure that water fills the gap between the ice block and the generating surface in each cycle.
This embodiment is similar in design and operation to the previously described conical embodiment except that the ice generating surface has the form of a truncated pyramid, which generating surface is fixed in the end of a vessel of prismatic shape. In this embodiment the cross-section of the pyramid is gradually adjusted so as to make a smooth transition to a round cross-section where the pyramid meets the circular ram. This embodiment is the basis for Claim 9. This embodiment is shown in
To generate large volumes of ice, multiple flat, conical or pyramidal generating surfaces may be combined to make an array in the form of a grid. A number of different methods are described in the following. Some of these are shown in FIGS. 6,7 and 8. All of the following embodiments can be scaled to a vessel of any length and width. This is the basis for Claims 12 through 18.
In some of the following embodiments the individual ice blocks are kept separated. One method to maintain this separation is to constrain the end of each block from moving sideways. This can be done by making deep indentations, in the shape of the free ends of the ice blocks, in whatever surface contacts the ends of the ice blocks. In some cases the free ends of the ice blocks are at the end of the vessel. In other cases the free ends are supported by a moving insulated plate. Said moving insulated plate is held in place by hydraulic cylinders or other means, such that it exerts little force during the ice generation mode, but in the consumption mode forces the ice blocks against the generating surface so as to promote rapid consumption.
An alternate method of maintaining the separation between the ice blocks is to place vertical guide rails for the full height of the tank, between the ice generating surfaces. In those embodiments in which the ice block moves vertically, these rails could if necessary be heated to slightly above 0° C. during the melting phase, to prevent the ice block from adhering to the rails.
G.1 Multiple Generating Surfaces, Each in the Form of the Interior of a Cone or Pyramid, with Rams, Arranged in a Fixed Horizontal Grid at the Bottom of an Air-Filled Tank, at the Top or Bottom of a Water-Filled Tank, or at Both the Top and Bottom of a Water-Filled Tank
This embodiment is shown in
A simple modification to this design would allow for the tank to be water-filled. In this case the grid supporting the generating surface can be located either at the bottom of the tank, generating an ice block which moves upward as it is generated, or at the top of the tank, generating an ice block which moves downwards.
These embodiments are the basis for Claim 12.
A further modification of this design employs a water-filled tank with stationary generating surfaces at both the top and bottom of the tank. This doubles the capacity of the machine while using the same floor area. This embodiment is the basis for Claim 13.
In this embodiment a horizontal grid attached to multiple generating surfaces is suspended in a tank of water. In this embodiment the individual ice blocks are kept separated as described above in Section G. The grid moves vertically through a water-filled tank of any length and width, generating stationary blocks of ice as it moves. The generating surfaces may be on the lower face of the grid, in which case the grid starts at the bottom of the tank and moves upward through the tank, generating blocks of ice below the grid as it moves upward; or the generating surfaces may be on the upper surface of the grid, in which case the grid starts at the top of the tank and moves downward through the tank, generating blocks of ice above the grid as it moves downwards. This is the basis for Claim 14.
To consume the ice, warm refrigerant is circulated through the generating surfaces, while pressure is maintained on the entire grid to keep the warm surfaces in contact with the ice block. As the ice is consumed, the water produced passes through openings between the generating surfaces and returns to the water-filled part of the tank.
In a vessel shaped as a vertical column instead of a flat tank, any number of grids can be suspended in the water column, with stationary grids also at the top and bottom. The objective of this arrangement is to maximize the amount of ice generated per unit of area occupied by the tank. This is the basis for Claim 15.
G.2.a Multiple Generating Surfaces Attached to a Vertically Moving Horizontal Grid, with Each Generating Surface in the Form of a Square or Rectangular Flat Plate
In this embodiment the generating surfaces are flat plates attached to the top of a grid. Each generating surface can be moved by rams horizontally approximately one centimeter, and vertically a few millimeters. The grid is attached to the bottom of the tank with hydraulic cylinders or other linear actuators which are used only in the ice consumption mode. This embodiment is the basis for Claim 16.
Prior to operation, the grid is positioned near the top of the tank, and the water between the top of the tank and the generating surfaces is frozen. To begin operation, one-half of the plates, in a checkerboard pattern, are moved to the side and downward, separating the plates from the ice block at an angle of approximately 20 degrees. The resulting gap immediately fills with water, freezing within a few seconds. As soon as the new ice has sufficient strength, the remaining plates are moved in the same manner. The above steps are repeated, with the plates moving down and to the side in the reverse direction of the prior movement. At this point the horizontal actuators are at their starting position, and the vertical actuators have been retracted. To complete the cycle all of the vertical actuators are extended, which moves the grid downward and returns the grid and plates to their original relative positions. This is continued until the desired quantity of ice has been produced.
G.2.b Multiple Generating Surfaces Attached to a Vertically Moving Horizontal Grid, with Each Generating Surface in the Form of the Exterior of a Square or Rectangular Pyramid
In this embodiment multiple generating surfaces are attached to a grid which is suspended in a tank of water, with the generating surfaces on the top of the grid, pointing upwards. Each generating surface is in the form of the exterior of a pyramid, as described above in the section entitled “Incrementally moving generating surface in the form of the exterior of a pyramid,” and illustrated in
Prior to operation, the grid is positioned at the top of the tank with all of the actuators extended, and the water between the top of the tank and the generating surfaces is frozen. To begin operation, half of the generating surfaces, in the pattern of the black squares of a chessboard, are withdrawn from the face of the ice block. As gaps form between the generating surfaces and the ice blocks, water fills the gap. Within a few seconds new ice forms in the space left by the withdrawn generating surfaces, and the remaining surfaces are withdrawn. At this point all of the actuators are extended simultaneously, moving the grid downward into position for a new cycle. This process continues until the desired quantity of ice has been produced.
In an alternative arrangement of this embodiment the generating surfaces are attached to the bottom of a vertically moving grid, with the grid initially located at the bottom of the tank and the generating surfaces pointing downwards. In this case the tank could be water-filled or air-filled.
The above embodiment is the basis for Claim 17.
G.2.c Multiple Generating Surfaces Attached to a Vertically Moving Horizontal Grid, with Each Generating Surface in the Form of the Interior a Cone or of a Pyramid with Square, Rectangular or Hexagonal Base, with a Ram
In this embodiment multiple generating surfaces are attached to the top of a grid which is suspended in a tank of water, as shown in
Prior to operation, the grid is positioned at the top of the tank, and the water between the top of the tank and the generating surfaces is frozen. To begin operation, all of the rams are first rotated and then extended, pushing the entire grid downwards, and separating the ice blocks from the generating surfaces. As a gap forms between the generating surfaces and the ice blocks, water fills the gaps. Within a few seconds, new ice forms in the space left by the withdrawn generating surfaces. The rams are then simultaneously rotated and withdrawn, ice forms in this space, and a new cycle begins. This process continues until the desired quantity of ice has been produced.
In the following embodiments the ice generating surface extends lengthwise within a trough of any desired length. In the cases in which the generating surface moves vertically, the generating surface is attached to a plate or beam which runs the length of the trough. The beam is moved by a series of hydraulic cylinders or other mechanism. Note that in the embodiments which employ rams, the design of the generating surface, and the placement and number of the rams may be varied considerably.
H.1 Elongated Moving Generating Surface with Cross-Section in the Form of an Inverted “V”
H.2 Elongated Stationary Generating Surface with “V” Cross-Section and Rams
H.3 Elongated Moving Generating Surface with “V” Cross-Section and Rams
