US 3905206 A
In refrigeration apparatus of the kind having a normal refrigerating system of varporizer, compresser and condenser and in which neutral refrigerant agent can be admitted directly to the storage space to bring about rapid initial cooling, there is provided a partition dividing the storage space from a separated space in which the vaporizer is located. Gas circulating means cause circulation out of the storage space into the bottom of the separated space, up through the separated space and back into the storage space. To protect the drive motor for the circulating means from low temperature, the motor may have a housing which provides an insulation gap around the motor and is open at its upper side.
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Description (OCR text may contain errors)
United States Patent [1 1 Deubel et al.
[451 Sept. 16, 1975 REFRIGERATION APPARATUS  Inventors: Karl Deubel; Willi Weber; Dieter Schuchmann, all of Mainz, Germany 22 Filed: June 5,1974
211 App]. No.: 476,541
 Foreign Application Priority Data Mar. 22, 1974 Canada 195721  References Cited UNITED STATES PATENTS 2,013,264 9/1935 Buder .1 62/419 2,056,041 9/1936 Erbach 2,065,358 12/1936 Zarotschenzeff 62/64 2,255,947 9/1941 Starr 62/255 2,975,619 3/1961 Saunders 62/419 3,186,186 6/1965 Klcist 62/419 3,239,360 3/1966 Dixon v 62/64 3,512,370 5/1970 Murphy 62/64 Primary Examiner-William J. Wye
57 ABSTRACT In refrigeration apparatus of the kind having a normal refrigerating system of varporizer, compresser and condenser and in which neutral refrigerant agent can be admitted directly to the storage space to bring about rapid initial cooling, there is provided a partition dividing the storage space from a separated space in which the vaporizer is located. Gas circulating means cause circulation out of the storage space into the bottom of the separated space, up through the separated space and backinto the storage space. To protect the drive motor for the circulating means from low temperature, the motor may have a housing which provides an insulation gap around the motor and is open at its upper side.
7 Claims, 3 Drawing Figures REFRIGERATION APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention is concerned with improvements in or relating to refrigeration apparatus, especially deep freezers.
2. Description of the Prior Art A usual refrigerating system of refrigeration apparatus such as a deep freezer consists of vaporizer, compressor and condenser, and for separate rapid cooling there are provided ducts for refrigerating agent opening into the interior space of the freezer which can be connected to a container for the refrigerating agent there being a shut-off element in the duct.
Deep freezers of this kind serve for instance, for freezing pastry which is poor in fat and is based on wheat, for which purpose the temperature range from about +30C to below 7C must be passed extremely rapidly to prevent deterioration. When fresh goods to be frozen are put into such a deep freezer neutral refrigerating agent is passed from the refrigerating agent container through the ducts directly into the interior and directly acts upon the fresh goods. The refrigerating agent issuing from the refrigerating agent container and expanding and volatilizing thus directly streams into the interior, removes heat from its surroundings and cools the goods stored in the interior in a manner akin to shock-cooling. The goods are thereby frozen very rapidly and the temperature falls simultaneously to the desired value. After a period of time sufficient to freeze the goods to the core and to reduce the temperature to the desired value, the supply of refrigerating agent is interrupted. The consumption of refrigerating agent until this moment is relatively small. The conven tional refrigerating system of vaporizer, compresser and condenser advantageously controlled by a thermostat then serves to maintain the desired minimum temperature over a longer period of time.
It has been learned in practice that scarcely any air circulation occurs in such a deep freezer. After relatively long periods of time, the temperature at the top of the freezer is higher than at the bottom because the air warmed up on those side walls on which there is no vaporizer, moves upwardly but is not cooled to such an extent at the vaporizer that it can by its weight displace upwardly the air at the bottom of the interior.
SUMMARY OF THE INVENTION The object of the present invention is to provide refrigeration apparatus in which air circulation takes place so that in the interior space the air or other gas may have practically the same temperature throughout.
According to the invention there is provided refrigeration apparatus having refrigerating means including vaporizer, compresser and condenser, the vaporizer being in an enclosed interior space which receives the objects to be refrigerated, and further including a duct which opens into the interior space and through which refrigerating agent can be passed directly into the interior space, a partition wall dividing the said interior space into a storage space for the said objects to be refrigerated and a separated space in which the said vaporizer is located, there being a gas circulation path from the storage space through a lower passageway into a lower region of the separated space, up the separated space and back into the storage space from a higher region of the separated space through an upper passageway, and gas circulating means arranged to cause circulation of the gas in the interior space in that direction in the path.
Preferably, the partition is mounted with its upper and lower ends spaced respectively from top and bottom bounding walls of the interior space so that said upper and lower passageways are provided between the said ends of the partition and the said bounding walls, and the said separated space extends substantially the full height of said interior space.
The gas circulating means are preferably arranged in the separated space, more preferably at the bottom of the separated space, to ensure that the air or other gas is sucked from the bottom of the storage space, is driven upwardly through the separated space and along the vaporizer and passed back to the top of the storage space into which it is introduced again.
Drive motor or motors for the gas circulating means may be arranged at the bottom of the separated space and electrically connected to the exterior in the usual manner by means of a cable running through the wall. In the interior of a deep freezer, temperatures may reach values from to C during the supply of the refrigerating agent, at which low temperatures, the drive motors of usual gas circulating means are not operable, simply because the lubricating agents employe are too viscous at such temperatures.
Another object of the invention is therefore to arrange the drive motor or motors of the gas-circulating means in such a manner that they may also operate at temperatures from 70 to 80C in the interior of the freezer.
To this end, preferably the gas circulating means has a drive motor within the interior space and a housing for the drive motor which is generally spaced from the drive motor so as to provide an insulation gap around the drive motor and is open at substantially the whole of its upper side.
The space between the drive motor and its housing has an insulating effect. The cold air of e.g. 70 to 80C being circulated does not impinge directly on the drive motor but impinges on the housing and is diverted by it. The heat developed by operation of the drive motor itself together with the insulating air layer between the housing and the drive motor can prevent a drop in temperature of the drive to a value at which the drive is no longer operable.
BRIEF DESCRIPTION OF THE DRAWING Further advantages of the invention will appear from the following description of a preferred embodiment given by way of example and with reference to the accompanying drawing, in which:
FIG. I is a side view looking into the interior of a deep freezer embodying the invention with the door re moved;
FIG. 2 is a vertical section along line AA of FIG. I showing the door of the freezer and a carriage for the goods to be frozen;
FIG. 3 is a vertical section through a blower or fan of the deep freezer of FIG. 1 and its drive motor.
DESCRIPTION OF THE PREFERRED EMBODIMENT The refrigeration apparatus in the form of a deep freezer illustrated in the drawing has a generally rectangular cabinet 12 having an interior space 1 which receives the goods to be refrigerated. The cabinet 12 has an access door, not shown in FIG. 1, but to be seen in the open position in FIG. 2, a back wall 3, two side walls one of which is indicated by reference numeral 2, a top wall 6 and a bottom wall bounding the interior space. The interior space 1 is divided into a storage space 13 for the goods being refrigerated and a space 7 adjacent the side wall 2 separated from the storage space 13 by a partition in the form of a rectangular wall 4 which is mounted in position spaced from the wall 2 by suitable supports (not shown), with its upper and lower ends respectively spaced from the top and bottom walls 5, 6 so as to provide upper and lower passageways 19, for the circulation of the air of other gaswhich occupies the interior space 1. The separated space 7 thus extends the full height of the interior space 1.
A refrigerating system of usual type is provided, comprising a fluid circuit including compresser and condenser indicated by reference numerals 1O, 11 to be mounted on the top wall 6 within a common housing and a vaporizer 8 mounted on the side wall 2 within the separated space 7, advantageously as shown so as to be contacted by circulating gas entirely between the respective levels of the upper and lower passageways 19, 20. Gas circulating means in the form of one or more motor-driven fans 9 are located at the bottom of the separated space 7 and will be more fully described later. At the front side of the top wall 6, there is a switch box 25 having a control board containing those controls which do not have to be located elsewhere. The construction and arrangement of this refrigeration system will present no problem to the expert.
To charge the storage space 13 with goods to be refrigerated, a wheeled carriage 22 in which trays or shelves 23 carrying goods can be individually mounted is used. To facilitate loading of the carriage 22 through the access door, a trolley 24 is provided. The location of the compresser and condenser 10, 11 on the top of the casing 2 also facilitates the entry and removal of the carriage 22.
For the rapid initial cooling described above with reference to the prior art, these are provided in the interior space 1 ducts in the form of perforated pipes 26 closed at one end and having apertures indicated by reference numeral 27 which open into the storage space 13 for direct admission of refrigerant agent thereto. The pipes 26 are connectible at their other ends, and are shown connected, to a container 28 for the refrigerant agent which is suitably located exteriorly of and beside the cabinet 12, but may be elsewhere. Advantageously, as shown, the deep freezer has discharge pipes 29 passing through the top wall 6, through which excess gas in the interior space 1 can pass to the exterior. To save energy, the discharge pipes 29 may be connected to another deep freezer which is in the normal storage operational condition, so that the excess cold gases pass into the second freezer. In the discharge pipes 29 there is a shut-off element, e.g. a throttle valve, not shown, arranged to operate under a low pressure difference.
There is also a shut-off element adapted to close off the ducts 26 from the exterior of the freezer. This may be of known kind, and its provision will present no problem to an expert. Preferably this shut-off element can be opened by manual control and advantageously it has an actuation mechanism including switching means which after a predetermined period of time after opening of the element, causes the actuation mechanism to close the element. The actuation mechanism may also be linked to control means of the refrigerating system comprising the vaporizer 8, compressor 10 and condenser 11, eg by being coupled to the thermostat of the system which is in the interior space 1, in a manner such that the refrigerating system is brought into operation automatically on closure of the shut-off element for the ducts 26.
The fan 9 is driven in rotation by a drive motor 14 arranged beneath the fan blades and mounted within a housing 15 consisting of side walls 18 and a bottom wall 16 which are all spaced from the motor 14 so as to leave an insulating space 21 all around and beneath the motor except where the motor is supported. The housing 15 is entirely open at its top side. The bottom 16 advantageously slopes slightly downwardly, as shown, from the side walls 18 to a small central aperture 17, through which water may condense in the gap 21 can drain off. The bottom 16 is supported off the bottom wall 5 of the freezer. Even if the gas temperature in the freezer should reach to C during the supply of refrigerating agent through the ducts 26, continuous air circulation by the fan 9 is ensured because the heat generated locally by the motor 14 and the insulating effect of the gap 21 prevents the temperature of the motor 14 dropping to a temperature at which the motor ceases to operate.
The fan 9 or each of them if more than one are provided can be operated during both the introduction of the refrigerant agent for the initial rapid cooling and the subsequent normal refrigeration by the refrigerating system 8, l0, 11 to maintain a circulation of the air or other gas in the interior space I. The fan 9 draws the air through the lower passageway 19 by suction from the storage space 13 into the lower region of the separated space 7 and drives it upwardly through the separated space, past the full height of the vaporizer 8, to the upper region of the separated space, whence it passes through the passageway 20 back into the storage space. A substantially constant temperature is thus maintained throughout the storage space during the normal operation, and during the initial cooling the incoming refrigerant agent is efficiently circulated.
In this connection, the refrigerating agent should be which can be compressed to be filled into containers and is neutral with respect to foodstuffs, such as nitrogen, carbon dioxide, or the like. Nitrogen is particularly preferred. But other gases neutral with respect to foodstuffs with which correspondingly low'temperatures are achievable may be used.
While the invention has been illustrated above by reference to a preferred but non-limitative embodiment thereof, it will be understood by those skilled in the art that various changes may be made without departing from the spirit and scope of the invention and it is intended to cover all such changes and modifications by the appended claims. What is claimed is: 1. Refrigeration apparatus having a. an enclosed interior space to receive goods to be cooled, b. refrigerating means including vaporizer, compressor and condenser,
c. at least one duct opening into the interior space and being adapted for supplying within the interior space a refrigerating agent,
d. a partition in the interior space dividing the interior space into a storage space for the said goods to be cooled and a separated space, the said vaporizer being in the separated space,
e. upper and lower passageways communicating the storage space and the separated space,
f. gas circulating means arranged to cause the gas in the interior space to circulate out of the storage space into the separated space through the said lower passageway, upwardly through the separated space, and out of the separated space into the storage space through the said upper passageway, said gas circulating means including a drive motor within the interior space, and a housing for the drive motor which is generally spaced from the drive motor so as to provide an insulating gap around the drive motor, said housing at its upper side providing an opening through which a part of the drive motor is adapted to extend.
2. Refrigeration apparatus according to claim 1 wherein the said partition is mounted with its upper and lower ends spaced respectively from top and bottom bounding walls of the interior space so that said upper and lower passageways are provided between the said ends of the partition and the said bounding walls, and the said separated space extends substantially the full height of said interior space.
3. Refrigeration apparatus according to claim 1 wherein said gas circulating means are arranged in a lower region of said separated space so as to suck gas out of the storage space through the said lower passageway and drive it upwardly in the separated space.
4. Refrigeration apparatus according to claim 1 wherein said condenser and compresser are arranged on a casing bounding the said interior space and are connected to the vaporizer through the said casing.
5. Refrigeration apparatus according to claim 1, wherein the lower side of the housing of the drive motor is constituted by a wall having an aperture through it, the wall being spaced from a bottom bounding wall of the said interior space.
6. Refrigeration apparatus according to claim 5 wherein the said bottom wall of the housing of the drive motor slopes downwardly to the said aperture in the bottom wall.
7. Refrigeration apparatus having a. a Cabinet in which there is an enclosed interior space to receive goods to be refrigerated, the cabinet having top and bottom walls and side walls bounding the interior space and a door for access to the interior space,
b. refrigerating means comprising interconnected vaporizer, compresser and condenser, the compresser and condenser being mounted on the cabinet outside the said interior space,
c. at least one perforated pipe extending through the interior space and being adapted to supply to the interior space a refrigerating agent, a discharge duct being provided for the discharge of excess gas from the interior space,
d. a partition wall in the interior space spaced from and facing a said side wall of the cabinet so as to divide the interior space into a storage space for the goods to be refrigerated and a separated space which extends substantially the full height of the interior space, the partition wall having upper and lower ends respectively spaced from the said top and bottom walls so that upper and lower passage ways are provided for gas circulation between the storage and separated spaced, the said vaporizer being located in the said separated space so as to be contacted by circulating gas between the respective levels of the said passageways,
e. at least one gas circulating fan and a drive motor therefor in a lower region of the separated space and arranged to suck gas from the storage space into the separated space through the said lower passageway and to drive the gas upwardly in the separated space past the vaporizer and into the storage space through the said upper passageway, and
f. a housing for the said drive motor comprising side walls and a bottom wall all spaced from the drive motor so as to provide an insulation gap substantially all around the motor and beneath it, the housing being open at substantially its entire upper side, there being a small aperture in the bottom wall of the housing being spaced from the bottom wall of the cabinet and sloping downwardly towards the said aperture.