DE1932694A1 - Control device for cooling systems - Google Patents

Description

PATENT ADVOCATE DIPL-ING.

HELMUT GÖRTZ

6 Frankfurt am Main 70 2o. June 1969

Sehnedcenhofstr. 27 - Τ · Ι. βΐ 70 79 q. _z ^ A ₀

DUAL JET REFRIGERATION CO., 'Chicago, Illinois

Control device for cooling systems

The invention relates to an improved plant for operation of cooling systems. The invention particularly relates to cooling devices with moving air currents, which create and maintain the cooled state in areas of the system that are within or close to the path of the air flow lie.

In describing the present invention, reference will be made to freezers such as those normally found in supermarkets for the storage of foodstuffs that need to be kept at reduced temperatures. In a special one Embodiment, air curtains q.uer are moved over an access opening for the freezer and the state of the curtain is regulated in order to achieve an effective operation of the system.

In US patents i \ r. 3,134,243 and 2,862,369 Chilled .Sales chests described, which with -bntzugöffnungen exposed to the atmosphere, capable of keeping the contents in a refrigerated state to keep. The loss of cooling from the exposed opening becomes most effective with these designs Use of a gas curtain »preferably an air curtain

009825/1082

19326S4

ges, prevents it from running continuously across the open side from one edge of the opening to the opposite Edge is promoted.

The air curtain in these embodiments is made of closely spaced Formed air fields, the most inner air field being a cooled air field of cold air and wherein one or more outer air fields have temperatures that are closer to the ambient temperature. It has It has been found that it is desirable to recirculate the internal cold air stream and provide means for purging it of the neighboring guide fields in order to maintain the cooling and the enclosed interior in a sufficiently cooled state to obtain.

The described embodiments work effectively during normal business hours guaranteed. The cooling device and the defrosting device work here in a desired order so that the product is stored at the desired temperature while the front of the freezer is open to allow customers to remove it.

Of course, this working method could also be used during the Times in which the business is closed can be maintained, e.g. B. during the night. It is clear, however, that it is it is quite expensive to maintain the same state of refrigeration and defrosting during the times when the store is open closed is; therefore facilities should be provided in order to make the plant economical during such times operate.

00982 5/1082

The object of the invention "is to provide an improved control device for cooled interiors, which allows an economical operation of the system, preferably during of non-business hours and which provides an alarm system that can be used both during business hours and during Non-business hours is usable.

In one embodiment of the invention is a control device provided, which can be used together with a cover device for the night, so that the economic Operation can be increased during non-business hours, whereby the control system prevents the goods from spoiling, if the system fails during non-business hours.

Further features, advantages and possible applications of the new invention emerge from the accompanying illustrations of exemplary embodiments as well as from the following description.

It shows:

Fig. 1 is a front elevational view of a cover device for the night as it is used in the facility,

Pig. 2 is a vertical sectional view of a freezer for the use of the device according to the invention;

3 ', an enlarged partial sectional view taken along the line 3-3 of Fig. 1, which illustrates the means to attach the sewing cover to the freezer,

009825/1082

4 is an enlarged horizontal partial sectional view dar night cover plate,

Pig. Figure 5 is a graph of operating temperatures a freezer,

Pig. 6 is a circuit diagram illustrating the monitoring devices according to the invention, and

7 shows a detailed illustration of the time-delayed Rules that will be used in the intended facility.

As already said, the present invention is described with reference to exemplary embodiments, which air curtains have in a side-by-side arrangement across a removal opening of the refrigerated display case. Such air curtains are usually intended to form barriers that prevent the loss of cooling or keep it as low as possible.

The invention is described in more detail with the aid of a freezer which has an opening in a wall to a Allow removal from the space inside the chest. The chests or showcases are provided with a large number of nozzles, those in a side-by-side transverse arrangement on one side of the discharge opening and corresponding inlet openings, the opposite are arranged on the opposite side of the removal opening, are provided. The inner nozzles and inlet ports are provided for the passage of a cooling stream across aie extraction opening, in which the adjacent outer Nozzles and openings flow around progressively warmer air fields. The internal cooling flow is circulated through a passage in which there are cooling coils and one or more of the Currents that are further outwardly adjacent can also be cooled. One embodiment of the present invention relates to

009825/1082

13326S4

the use of a cover plate for the night, which is put in place during non-business hours. The night cover plate includes an insulated board, which keeps the cold inside the chest to a greater extent than when the removal opening is not closed or is closed with a non-insulated plate. With this facility, the product can stored inside the chest in a safe temperature range while the energy for maintaining the cooling state can be reduced. The night cover plate can be used in conjunction with a monitoring circuit to monitor the loss of refrigerated items if the refrigeration fails should be kept to a minimum or if another interruption in work should occur. The monitoring system can also can be used independently of the night cover plate.

The circuit arrangement according to the invention comprises devices which interrupt the operation of the rotating fans and the anti-freeze heating. Plus the circuit is for it provided in order to exclude the possibility of starting a defrost cycle if an error has occurred. In the end warning lights and alarm devices can be built into the circuit, so that all efforts to eliminate the errors, can be done as soon as possible.

Figures 1-4 illustrate a refrigerated showcase 1o and one associated cover plate 12 for the night. The cooling system includes an upper wall 14 »a lower wall 16, a rear wall and front wall 2o. The front wall forms an opening 22 which enables removal from the interior 24 of the system. shelves 26 to 32 and the bottom 34 serve to accommodate the products that are stored within the system. viTie the plants that in the aforementioned patents, the device shown also comprises a partition wall 36 »which the outer vYand into an inner channel 38 and an outer channel

009825/1082

ι \ J yj c— \ j

4o divided. Cooling devices 42 are placed in the inner duct and circulation fans 44 are in both ducts intended.

There are inlet openings 36 for each channel and the Air currents are suitable to move from the outlet nozzles 48 across the extraction opening to the inlet openings 46

Air circulates through the system during normal operation the inner channel 38, whereby the cooling devices 42 cause a cooled air flow to cross the discharge opening. The second circulating flow, which moves in the channel 4o and over the extraction opening, serves as a guide flow. An additional Electricity can be provided to bring ambient air into the ! To pull the guide 47 by means of the fan 49 and to blow off the ambient air through the outermost nozzle 48.

The cover plate 12 for the watch consists of an insulating material and can be formed from a multiplicity of individually closed parts 5o. A wood or plastic 51 is molded around the parts 50 and a protective aluminum or plastic skin 53 may be provided over the face and back of the parts. Urethane is particularly suitable as a material for such a board. The fields can be advantageously prepared _f wherein the skin is attached to the frame 53 51, in order to create hollow walls, in which then the foaming material is introduced by "foaming in place".

The frame 51 comprises a U-shaped gibied with legs that extend into outer strips 1o2 and inner strips 1o4 are divided. These strips form a slot 1o6 for receiving the front and rear walls 53. The ends 1o8 of the strips 1o4 are bent over to provide a holding device for the insulating material 5o. This holding device is particularly desirable

009825/1082

19326S4

when the material is foamed in place.

The base plate 1o of the U-shaped frame member forms inner Grooves 112. These grooves are suitable for the lower part 114 which consists of flexible magnetic elements 116. These elements have elongated pockets 118 which receive the magnets I2o.

The design of the frame part 51 facilitates to a great extent the formation of individual sections of the cover plate 12 for the night. When the cover plate is in place on the refrigerated display case opening is brought, then the magnets I2o in the outermost area attract a magnetic strip 122, which is round is firmly attached around the outer edge of the removal opening.

The use of magnetic tape or other material which attracts the magnet I2o is required where the components of the showcase are made of magnetic material.

The parts are dimensioned so that the assembled parts have a width that is slightly less than the width of the removal opening. This provides joints between the parts when they are attached, as in FIG. 1 and 4 can be seen. These joints are filled because of the flexibility of the magnetic holding means. This ensures flexibility the placement of a seal between the frame members and the peripheral wall of the dispensing opening and between the one lines Partl The upper and lower frame members have a slightly different design. As seen in FIG. 3 is, the upper frame member 124 has a stepped portion to receive the magnetic retention means 116. The magnetic one Material in the holding means attracts the magnetic strip .126 which is attached over the front surface of the innermost nozzle 48 is.

009825/1082

The lower frame member 128 forms downwardly extending portions 13o, with shoulders resting on the U-shaped bar 132 rest. Magnetic material 134 is on the lower surface attached to this rod in order to achieve the desired visual effect.

It has been found that the use of magnetic gaskets around the entire cover plate fairly is important so that a secure seal is achieved everywhere. Any leaks will cause icing and themselves few leaks can be very disadvantageous.

The graphic representation in i ^: ig. 5 illustrates the conditions inside a refrigerated chest of the type shown in Pig. 2 is shown when cooling is lost. The obtained temperature measurements were started after the heat of the defroster was removed from the refrigerated display case. From then on, temperature measurements were taken every hour up to 7 hours and finally the last temperature measurement after 7 1/2 hours. During this time the cover plate 12 was in place for the night and the coolers were not operating, so the test simulated a situation where the cooler failed.

During the test, ice cream was in the refrigerated display case and thermocouples were embedded in the ice cream to reflect the temperature to measure the product at different points within the chest. There were gallons and in the chest Pint Containers »however, all thermocouples were connected to pirit containers except for one thermocouple, which was connected to a Half a gallon container was attached to the front of the 3rd shelf 3.0.

009825/1082

1932684

At the beginning of the test, the ice cream had temperatures of -22 ° C to -24 ° G (-7 to - 10 ° F). After 7 1/2 hours had the temperature of the ice cream in the pint container at the front of the 1st shelf 26 increases to -1o ° C (15 ° F); all others tested Containers maintained temperatures between -16 ° C to -24 ° C (2 and 1o ° F). Since the temperatures are well within the range required to store the ice cream, the use of the cover plate for the night in conjunction with the subsequent control circuit creates a completely safe facility.

The control circuit that is used for the refrigerated display case 1o is shown in FIGS. 6 and 7 and includes a temperature measuring head 6o, which is preferably on one of the cross braces 61 between the evaporator coils (see Fig. 2) is attached and which is connected to the control element 62. This element is designed so that the switch 64 closes when the measured temperature exceeds a certain vVert. In one embodiment of the invention element 62 is set so that switch 64 closes when the temperature exceeds -7.5 C (O F).

The switch 64 is through the line 66 and the terminal box 67 connected to the switch 68. The switch 68 comprises the main switch for the control circuit. The switch can be a manually operated switch, which in the open State completely disconnects the control circuit from the electrical network. This is e.g. B. desirable when the Cooling system is being serviced.

The switch 64 looks over lines 66 and 7o and the terminal boxes 67 and 71 a voltage of 115 volts for the time

009825/1082

1332694

- 1ο

delay relay 72 before. The circuit comprises a clockwork motor 74 (see Fig. 7) which begins to work both when switch 64 and switch 76, which is closed mechanically at the end of the preselected delay time, are closed. In one embodiment of the invention, the time delay relay 72 is set so that it closes the switch 76 25 minutes after the switch 64 is closed. The temperature monitoring unit 62 is designed so that the switch 64 opens again and the time delay relay 72 resets if the temperature sensed by the thermocouple 60 drops to -24 ° C (-I0 ⁰ I). Accordingly, during a defrost period when the temperature of the evaporator coil reaches -7 »5 G (0 F), the switch 64 closes, energizing the timer mechanism 74 in the time delay relay 72, when the temperature of the coil reaches -24 ° C (-I0 ⁰ P ) reached before the end of the 25 minute time delay, then switch 64 opens and the time delay relay 72 resets itself. In such circumstances switch 76 is never closed.

However, if the cooling device is not working properly, then the switch 76 is closed mechanically after 25 minutes. This energizes relay 78 and opens normally closed switches 80 and O2. These switches are preferably in the power lines to the anti-sweat heaters and to the "fan motor lead" so that these devices do not work when the switches are open are. U.S. Patent No. 3,243,971 provides an arrangement of heating elements for "preventing icing. The heating elements 92 of the type shown in U.S. Patent No. 3,4o3,525 can also be provided to allow the frost to set in prevent, and the control circuit can also be provided to the power supply to such heating elements interrupt.

009825/1082

Closing switch 76 also energizes relay 84, thereby closing switches 86 and 88. The switch 86 switches the defroster mechanism 87 for the device so that defrosting cannot take place after a loss of Cooling. The switch 88 can be connected to an alarm device which is used to warn the warehouse keeper. The lamp 9o is switched on when the switch gear 76 is closed so that a visual indication of the fault is provided.

The establishment can of course with the same success in different TemperaTburregeleinrichtungen are applied, z. B. in showcases with higher temperatures.

As shown in Fig. 4, a spring loaded switch 89 can be attached so that when the night cover plate is on their place, the switch is closed and the same puncturing method as the switch 86 shown in Fig. 6, Has. With this switch, which is connected to the defrost limit control, defrosting cannot take place if the night cover is in use. This is highly desirable because most refrigerated display cases defrost precisely at regular intervals, e.g. B. every four hours; 6 times a day. This way you can when the night coverage is used, 3 defrosting processes can be avoided without difficulty, since no frost at all reaches the lines if the night cover is in place. In addition, energy is saved because heat penetrates the refrigerated display case while defrosting does not have to be removed. Alternatively, the switch 89 can serve as an operating switch for the control device, e.g. B. if the switch is in Series with the switch 68 is switched.

009825/1082

The night cover and the control device can be used in connection with various embodiments of the refrigerated display case. Y / enn if you at the in I ¹ Ig. 2 is used, the night cover is preferably arranged in the area between the first guide stream and the cooled stream. During operation at night, the rotating fan for the guide currents can be switched off so that only the rotating fan for the cooling flow works. This can be done automatically by placing a suitable push button switch at some point around the periphery of the dispensing opening so that the switch is actuated when the cover is in place for the night.

The night cover and the control device according to the invention are particularly useful in a system with a defrosting device that only works when defrosting is desired. In this way, in some systems, defrosting takes place automatically at adjustable intervals, e.g. B. every four hours. Accordingly defrosting would take place during the night, whether there is now is desired or not. If I installed cooling devices to feel the need for defrosting so that this mode of operation only takes place when it is desired, then savings are realized because it has been found that the use of the night cover takes the approach of frost prevents defrosting to the extent that it is not necessary during the entire non-business period.

During extremely high outside air conditions, it is possible that After a defrosting process, the compressor may have difficulties reducing the temperature or being switched off can, as a result of high head temperatures or a non-uniform Temperature shielding of the motor windings. With the inven-

009825/1082

1S32694

proper control system will work if the temperature of the snakes is not the preselected temperature in the preset When the time has come, the heat is automatically removed from the condensation unit by the fans and anti-sweat heating elements be switched off. This allows the condensation unit to lower the suction pressure, and to reduce the head pressure, wherein the condenser unit recovers and passes over the top of the charge, the facility not being waited for needs to be.

It is not intended that the means for cooling the showcase will be modified where night covers are generally used. The built-in compressor may have a smaller capacity and be built into a circuit that operates it continuously. With the night cover in place, the continued operation causes the product to get much colder than necessary. During the time when the covers are open, the product heats up because the compressor cannot maintain the low temperatures, but the rise in temperature can be controlled so that the temperature of the product never reaches an undesirable level. In this alternative embodiment, the evaporator coil operates at a higher temperature so that icing problems are greatly reduced. This allows the refrigerated showcase to be operated at higher humidity and at the same time creates better working conditions.

009825/1082

Claims (7)

-H- Claims Freezer or display case with a cooled interior and cooling devices with circulation devices to bring air into contact with the cooling devices and ducts, to direct the cooled air, thereby cooling the interior and an open side for extraction from the Inside the freezer, has inlet devices and corresponding Outlet devices on transversely opposite edges of the open side, the channels being the outlet devices and the inlet means and the circulation means connect air through the ducts and across drive the removal opening, characterized in that a cover plate has a size such that it closes the open side and formed of insulating material which keeps the cold inside the system, when the cover is in place that the cover consists of a plurality of sections and devices intended for sealing the interior of the cooling system are, whereby the. Cover separates the space formed by the air that traverses the extraction opening sweeps away from the environment of the cooling system, and that the sealing devices have magnetic means, .... '. which are arranged around the periphery of the removal opening and further magnetic devices are arranged on the edges of the areas of the cover and are flexible Holders for the magnetic means are provided, whereby a tight engagement of the magnetic means around the removal opening is achieved. 009825/1082 19326S4 2. Installation according to claim 1, characterized in that flexible holders are received by each area and the magnetic Material is held in place by the holders so that the holders are attracted to neighboring magnetic material, a sealing effect between the individual areas of the cover and between the cover and the To reach the walls of the cooling system. 3. Plant according to claim 2, characterized in that each Area has a frame surrounding it, that front panels are firmly connected to each frame and extend over the outer surfaces of the areas extend, and that an insulating material extends the space between the two face plates and the attached frame. 4. Plant according to claim 3> characterized in that the frame comprises a extruded plastic member that slotted side panels are formed by this frame in order to to accommodate the front panels, and that a grooved outer Wall is formed by this frame to accommodate the flexible holder. 5. Plant according to claims 1-4, characterized in that suitable control means for operation after attaching the cover it is provided that the control devices have temperature-sensing means and delay means which then work when the temperature sensing means a rise in temperature above a first previously set Indicate levels and that they will be reset if the sensed temperature is below a second previously set The temperature level falls before the temperature set on the delay element has expired, so that the time-toerzö- 009825/1082 1-9-3 26 S4 storage device, if it is not reset, interrupts the work of the circulating means and prevents the operation of the defrosting device until the temperature is reached is in the safe area. 6. Plant according to claims 1-5, characterized in that the defrosting device is connected to the interior and Has circuit devices that operate the defrosting device prevented when the cover plate is in place. 7. Plant according to claims 1-6, characterized in that a switch is located near the edge of the open side to operate the switch by means of the cover plate when the cover is in place. ' 009825/1082 Blank page