JP4884990B2 - Defroster for air cooler - Google Patents

Description

  The present invention relates to a defrosting device for an air cooler by steam spraying, and more particularly, to a defrosting device for an air cooler by steam spraying that defrosts in a low temperature room or a quick freezing freezing room such as a freezer refrigerator or a food manufacturing factory. It is.

  Conventionally, a hot gas method, an electric heater method, and a watering method are known as methods for removing frost attached to the cooling coil of this kind of air cooler. The hot gas system is a system in which hot gas discharged from a refrigerator is fed into a cooling coil to warm the inner surface of the coil tube and melt frost attached to the cooling coil.

The electric heater method is a method in which an electric heater is incorporated in a cooling coil (fin portion or the like) and frost is melted by the heat of the electric heater. Further, the watering method is a method in which water with a water temperature of 15 ° C. to 18 ° C. is sprinkled from the upper part of the cooling coil to melt frost (for example, see Patent Documents 1 to 3).
JP-A-11-37616. JP 2000-41800 A. JP-A-8-121940.

  The above-mentioned conventional hot gas system has a complicated system, a high-pressure liquid or gas condensed in the air cooler is processed again into a gas and returned to the suction section of the refrigerator, and the operation of the apparatus A system to control the system is required.

  Further, in the hot gas method, it is necessary to uniformly distribute the hot gas to the cooling coil, which increases the initial cost of the cooling coil. Furthermore, water generated by melting frost falls into a low-temperature drain pan and causes re-freezing. When hot gas is supplied to prevent this re-freezing, the heat of the hot gas is not easily transmitted to the drain pan or the like. There is a drawback that it grows again as an icicle by refreezing in a casing or the like. When carbon dioxide is used as the secondary refrigerant, the system is further complicated because it is necessary to raise the temperature of the carbon dioxide.

  On the other hand, although the electric heater system itself can be configured simply, the running cost such as electricity costs is high, and the electric heater may be disconnected or leaked. In addition, the heat of the electric heater may not be effectively transferred to the cooling coil and frost formation on the surface thereof, and the heat may escape to the outside to raise the temperature of the object to be cooled such as food. Furthermore, there are problems such as unevenness in defrosting and generation of residual frost.

  In addition, the watering method requires a large amount of water in order to spray water uniformly on the cooling coil, and the running cost is increased. In addition, equipment for producing hot water of 15 ° C. to 18 ° C. and spraying it on the cooling coil is required. In addition, in the system which collects the sprinkling after use, large-scale equipment, such as a large-capacity defrost water tank, a pump, and a water pipe, and a large-diameter recovery drain pipe are required. In addition, since the method of collecting water spray is not hygienic, particularly in food factories, etc., it becomes impossible to comply with the HACCP (Hazard Analysis Critical Point) system that establishes compliance standards for food hazard and critical control point methods.

  Further, in the watering method, a heat source such as an electric heater or a waste heat utilization device is required to keep the water temperature at a predetermined value. Further, there is a drawback that the sprinkled water scatters on the inner surface of the casing (skeleton) and re-freezes on the inner surface to grow as icicles.

  Therefore, there are technical issues to be solved in order to eliminate defrosting unevenness, frost remaining ice and re-freezing, effectively use steam that is always available in general food factories, etc., and reduce initial cost and running cost. The present invention aims to solve this problem.

A defrost device for an air cooler that introduces and cools air from a blower into a casing provided with a cooling coil,
A steam header for spraying steam is provided in the casing, and the frost adhered to the cooling coil and the casing is melted by the steam sprayed from the steam header .
Further, in the defroster of the air cooler configured to dispose a watering header above the cooling coil, and to spray a small amount of water to the cooling coil from the watering header,
Before SL steam header is provided in the vicinity above the drain pan formed in the casing lower, dissolved frost adhering to the drain pan to warm the entire drain pan by atomized steam from the steam header, then defrost the drain pan Steam provides a defrost device for an air cooler that rises to the opposite side of the drain pan, flows toward the cooling coil, and melts frost adhering to the cooling coil .

  According to this configuration, at the time of defrosting, the steam from the steam header provided in the casing is sprayed, and the cooling coil and the casing are warmed by the heat of the steam to melt the frost attached to the cooling coil and the casing surface. . Therefore, steam used in general food factories can be used as a heat source, and a large amount of water and electricity are not required.

  According to this configuration, the cooling coil and the casing are heated by spraying the steam from the steam header, and the frost adhering to the cooling coil and the casing surface is melted. Thereafter, a small amount of water is sprayed on the top of the cooling coil from a watering header provided above the cooling coil for cleaning. Therefore, steam is the only heat source, and the cooling coil can be cleaned with a small amount of water.

  According to this configuration, the steam is sprayed from the steam header to warm the drain pan at the lower part of the casing, and the frost attached to the drain pan is melted. Thereafter, the steam defrosted from the drain pan rises while gradually diffusing inside the casing, and melts the frost adhering to the cooling coil and the casing surface. In this case, the frost melts and water falls to the drain pan, but the drain port of the drain pan after defrosting is opened without being blocked (freezing), so the fall water is discharged to the outside from the discharge port. .

The invention according to claim 2 is characterized in that the casing has an air introduction part and an air discharge part, and each of the air introduction part and the air discharge part is provided with a damper which is closed at the time of defrosting. An air cooler defrost device according to claim 1 is provided.

  According to this structure, since the damper provided in the casing is closed at the time of defrosting, the heat of the steam sprayed in the casing does not escape to the outside of the casing.

  According to the first aspect of the present invention, since the cooling coil and the entire casing are uniformly heated by the heat of steam to melt the frost, it is possible to eliminate defrosting unevenness, frost remaining ice and re-freezing. In particular, since steam spreads over the entire space in the casing, the entire cooling coil can be efficiently defrosted, and steam that is always available in general food factories or the like can be used effectively.

  Further, since a large amount of water or electricity is not used unlike the conventional watering method and electric heater method, the running cost is reduced. Furthermore, since steam, which is a heat source, is used in general food factories, it is only necessary to install a steam header in the casing, so there is no need for large-scale equipment and the initial cost is higher than that of the conventional method. To reduce.

This invention, similarly to the effect defrosting unevenness, without the remaining ice or reicing frost, effectively using the heat source defroster, it is possible to reduce the initial cost and running cost, in addition, The cooling coil can be cleaned by watering, and it becomes hygienic as compared with the conventional one, and can sufficiently meet the hygiene standards of HACCP in food factories and the like.

This invention, since it defrosting warm directly just not drain pan also steam thermal cooling coil and the casing, in addition to the above effects, it is not necessary to provide an electric heater or the like for re deicing the drain pan. Moreover, the water which accumulates in the drain pan after defrosting can be smoothly discharged | emitted from the drainage channel of a drain pan.

According to the second aspect of the present invention, since the heat of the steam does not escape outside the casing by closing the damper provided in the casing at the time of defrosting, in addition to the effect of the first aspect, the defrosting with high thermal efficiency is performed. And defrost time can be shortened.

  The purpose of the present invention is to eliminate defrosting unevenness and prevent residual frost from being generated, to effectively use steam that is normally used in general food factories, etc., and to reduce initial costs and running costs. In a defrost device of an air cooler that cools air by introducing air from a blower into a casing provided with a steam header, a steam header that sprays steam is provided in the casing, and the cooling coil and steam are sprayed by the steam sprayed from the steam header. It was comprised so that the frost adhering to the casing might melt | dissolve, and the watering header was arrange | positioned above the said cooling coil in the said casing, and it achieved by sprinkling water to the said cooling coil from this watering header.

  A preferred embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a cross-sectional view illustrating a configuration of an air cooler according to the present embodiment, and FIG. 2 is an explanatory diagram illustrating an overall configuration of the present embodiment. This embodiment is applied to a defrost device for an air cooler installed in a refrigerator or the like, and melts frost by blowing low-pressure steam toward a drain pan to which frost (including ice) adheres. Later, when the steam rises toward the cooling coil in the casing, the frost attached to the cooling coil and the casing can be dissolved.

  In FIG. 2, reference numeral 1 denotes a refrigerator including a compressor 2, a condenser 3, and a liquid receiver 4. The refrigerator 1 is provided in a refrigeration warehouse 7 or the like via a refrigerant outgoing pipe 5 </ b> A with an expansion valve 6. The air cooler 8 is connected to the refrigerant inlet. The refrigerant outlet of the air cooler 8 is connected to the suction side of the compressor 2 through a refrigerant return pipe 5B.

  Next, the detailed structure of the air cooler 8 will be described. As shown in FIG. 1, a casing (including a skeleton) 12 of the air cooler 8 is formed in an upper surface opening type covered with a heat insulating material 12 a, and is discharged to an upper surface opening (air discharge portion) 13 of the casing 8. A damper 14 is provided so as to be capable of opening and closing. Also, a blower 15 for taking in air into the casing 12 from the outside is attached to one side of the casing 12, and a suction damper 16 is provided at the downstream portion (air introduction portion) 15 </ b> A of the blower 15 so that the suction damper 16 can be opened and closed. It has been.

  A cooling coil 17 for cooling the air is disposed substantially in the center of the casing 12, and the cooling coil 17 includes a fin and a coil tube. A refrigerant inflow pipe 18 and a refrigerant outflow pipe 19 are connected to the inflow side and the outflow side of the cooling coil 17, respectively, and the refrigerant (for example, carbon dioxide) in the cooling coil 17 flows into the cooling coil 17 from the refrigerant inflow pipe 18. Then, after rising while changing the flow direction alternately left and right, it returns to the condenser 3 through the refrigerant outflow pipe 19.

  Reference numeral 21 denotes a thermostat that operates when the temperature in the casing 12 reaches a set value. This operation signal is transmitted to a control unit (not shown) to control the operation of the air cooler 8.

  The air cooler 8 includes a cleaning / sprinkling device 22 for cleaning the cooling coil 17. The washing / sprinkling device 22 includes a watering header 23 that is horizontally provided immediately above the cooling coil 17, and a watering pipe 25 with an electromagnetic on-off valve 24 having one end connected to the inflow side of the watering header 23. It consists of. Since a water supply unit (not shown) is connected to the other end of the watering pipe 25, tap water (washing water) can be supplied to the watering header 23 by opening the electromagnetic on-off valve 24. it can.

  A plurality of water spray nozzles 26, 26... Are provided on the lower surface side of the cleaning / sprinkling apparatus 22 with a predetermined interval in the horizontal direction. The entire cooling coil 17 can be cleaned by spraying the cleaning water from the water spray nozzles 26, 26... On the cooling coil 17.

  In addition, a drain pan 27 is formed in the lower part of the casing 12, and water sprayed from the water spray header 23 falls and is stored in the drain pan 27. The water accumulated in the drain pan 27 (including water in which frost is melted) is discharged to the outside through the drain pipe 29 through the drain port 28 provided in the lower part of the drain pan 27.

  Further, the air cooler 8 includes a steam device 30 for melting frost attached to the cooling coil 17 with steam S. The steam device 30 includes a steam header 31 provided horizontally just above the drain pan 27, and a steam pipe 33 with an electromagnetic on-off valve 32 having one end connected to the inflow side of the steam header 31. Since a steam supply unit (not shown) is connected to the other end of the steam pipe 33, the low pressure steam S can be supplied to the steam header 31 by opening the electromagnetic on-off valve 32. .

  A plurality of steam nozzles 34, 34... Are provided at predetermined intervals in the horizontal direction on the lower surface side of the steam header 31, and by spraying steam onto the drain pan 27 from the steam nozzles 34, 34. The frost attached to can be melted.

  In the air cooler 8 having the above configuration, frost attached to the surface of the cooling coil 17 and the like is removed by a defrost start command. When starting the defrosting, when the pressure sensor (not shown) detects that the pressure loss in the tube of the cooling coil 17 has become a constant value or the time set in advance by the timer, The refrigerant is collected in a low-pressure receiver or the like (not shown), and the operation of the blower 15 is stopped after the refrigerant is collected.

  Thereafter, the suction damper 16 and the discharge damper 14 are automatically (or manually) switched to a fully closed state, and then the electromagnetic on-off valve 32 is opened to supply low-pressure steam S from the steam header 31. As a result, low-pressure steam is sprayed toward the drain pan 27 from the steam nozzles 34 of the steam header 31, and the entire drain pan 27 is warmed by the heat of the steam S. For this reason, the frost adhering to the surface of the drain pan 27 is melted by the heat of the steam S. Thereafter, the steam S gradually rises, and the frost attached to the cooling coil (fin, coil tube) 17 and the casing 12 is also melted.

  As described above, in this embodiment, the suction damper 16 and the discharge damper 14 are provided in order to effectively use the steam that is always provided in a general food factory and to eliminate heat loss. Thus, by closing the suction damper 16 and the discharge damper 14 at the time of defrosting, the heat of the steam S does not escape to the outside of the casing 12, so that highly efficient defrosting with less heat loss is performed.

  The operation of the defrost caused by the steam spray will be described in detail. First, the steam S is uniformly ejected toward the entire surface of the drain pan 27 by the plurality of steam nozzles 34 provided on the lower surface of the steam header 31. The entire drain pan 27 is warmed by the jetted steam S, and the frost attached to the drain pan 27 is surely melted. The melted water is guided to the drain port 28 and discharged to the outside through the drain pipe 29.

  Next, the steam S defrosted from the drain pan 27 gradually changes its direction to the side opposite to the drain pan 27 and rises, flows to the cooling coil 17 side, and diffuses and rises in the space inside the casing 12. As a result, a part of the steam S rises in contact with the surface of the cooling coil 17 and the inner surface of the casing 12, so that the entire cooling coil 17 and the casing 12 are uniformly warmed, and frost adhered to the cooling coil 17 and the casing 12. Make sure to dissolve.

  The water generated by the frosting of the cooling coil 17 and the casing 12 is dropped to the drain pan 27. The drain pan 27 is heated by the steam S and has risen to a predetermined temperature or more. The water will not freeze again.

  In this embodiment, since the defrost time for one time is usually about 20 minutes, the size of the air cooler 8, that is, the shape and dimensions of the cooling coil 17 and the casing 12, and the frost attached to the cooling coil 17 are reduced. The supply amount of the steam S can be accurately determined by calculating the heat balance in advance according to the amount. Further, the temperature around the steam header 31 is detected by a thermostat 21 or a temperature sensor (not shown) mounted in the casing 12, and the supply amount of steam is automatically controlled via the control unit based on the detection signal. . Furthermore, the defrost time can be set to an optimum time according to the operating conditions by a timer.

  Note that when the defrost mode ends, the thermostat 21 detects the ambient temperature in the casing 12, and when the ambient temperature reaches 30 ° C to 40 ° C, the supply of the steam S is stopped. The supply of the steam S can be stopped by using a setting of a defrost time (about 20 minutes) by a timer.

  Thus, after the defrosting by the steam spraying is completed, the cleaning / sprinkling device 22 uniformly sprays the cleaning water on the upper portion of the cooling coil 17 for cleaning. At that time, the entire cooling coil 17 can be effectively cleaned by spraying the washing water on the upper part of the cooling coil 17 from the watering nozzles 26 provided on the watering header 23. it can.

  Next, when the cleaning by the cleaning / sprinkling device 22 is completed, draining is performed for the time set in the timer, and then a low-temperature refrigerant is supplied into the cooling coil 17, and the temperature in the casing 12 is preset. When the temperature is lowered to a low temperature, the suction damper 16 and the discharge damper 14 are fully opened, and the cooling operation of the air cooler 8 is started by starting the blower 15.

  In the present embodiment, since the casing 12 has high heat insulation performance, heat loss of the steam blown into the casing 12 can be prevented as much as possible, and the defrost time can be further shortened. Further, since the steam S does not come out of the casing 12 by closing the suction damper 16 and the discharge damper 14, the temperature outside the casing 12 is prevented from rising. Therefore, the temperature rise of the product to be cooled (food, etc.) existing outside the air cooler 8, for example, a refrigerator-freezer, can be effectively prevented, thereby contributing to ensuring the quality of the product to be cooled.

  Actually, when the air cooler 8 shown in the figure is installed in a food factory and the defrost is tested using low-pressure steam, a small amount of low-pressure steam is sprayed from the steam header 31 so that the atmosphere around the cooling coil 17 is obtained. The temperature was raised to 30 ° C. to 40 ° C., and the ambient temperature could be made uniform. Thus, the unevenness of the defrosting is eliminated, the frost remaining ice is not generated in the cooling coil 17, and the surface temperature of the drain pan 27 and the casing 12 is reliably 10 ° C. or higher. As a result, there was no re-freezing and good defrosting could be performed.

  The air cooler 8 of the present embodiment only needs to be provided with a steam device 30 for supplying low-pressure steam into the air cooler 8, and does not require a large facility. In addition, since the equipment for generating low-pressure steam is usually installed in food factories, no new equipment is required.

  Unlike the conventional hot gas system, a condensed high-pressure gas, a large-sized device for converting the liquid into a low-pressure gas again, and its control system are unnecessary. Further, unlike the conventional watering method, a defrosting water tank, a supply pump and many pipes are unnecessary, and the equipment is simplified and the initial cost is reduced. In addition, a large amount of electricity and water are not required, and the running cost is low because only the amount of low-pressure steam is used, and there is no problem of re-freezing, and maintenance is not required.

  As described above, according to the present invention, the cooling coil 7 and the casing 2 are heated by the heat of the steam to melt the frost, so that the entire cooling coil 17 and the drain pan 27 are efficiently defrosted, and can be used in a general food factory or the like. It is possible to effectively use the steam that is always available.

  Moreover, since it is only necessary to attach the steam header 31 to the existing equipment, a large-scale equipment is not required and the initial cost is reduced. In addition, since the cooling coil 17 can be cleaned with a small amount of water, the running cost can be further reduced and it becomes very hygienic.

  Further, it is not necessary to provide an electric heater for preventing re-freezing in the drain pan 27, and water generated by melting of the frost in the cooling coil 17 falls to the drain pan 27 and is quickly discharged without re-freezing.

  In addition, an exhaust hole (not shown) provided with an automatic damper is provided in the upper portion of the air cooler 8 of the present invention, and is configured to automatically prevent an increase in internal pressure in the air cooler 8, Further, an exhaust hole (not shown) provided with an automatic damper is provided at the lower part of the air cooler 8 in order to automatically discharge the internal high-temperature air after steam spraying when the above watering is not performed. Is provided.

  The present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

Sectional drawing which shows one Example of this invention and demonstrates the structure of an air cooler. Explanatory drawing which shows the whole structure of the refrigerator warehouse to which the air cooler of a present Example was applied.

Explanation of symbols

8 Air cooler 12 Casing (skeleton)
12a Heat insulation material 14 Discharge damper 15 Blower 16 Suction damper 17 Cooling coil (fin, coil tube)
18 Refrigerant Inflow Pipe 19 Refrigerant Outlet Pipe 21 Thermostat 22 Washing / Sprinkling Device 23 Sprinkling Header 26 Sprinkling Nozzle 27 Drain Pan 28 Drain Port 29 Drain Piping 30 Steam Device 31 Steam Header 34 Steam Nozzle

Claims (2)

A defrost device for an air cooler that introduces and cools air from a blower into a casing provided with a cooling coil,
A steam header for spraying steam is provided in the casing, and the frost adhered to the cooling coil and the casing is melted by the steam sprayed from the steam header .
Further, in the defroster of the air cooler configured to dispose a watering header above the cooling coil, and to spray a small amount of water to the cooling coil from the watering header,
The steam header is provided near the drain pan formed in the lower part of the casing, the steam sprayed from the steam header warms the entire drain pan, melts the frost attached to the drain pan, and then defrosts the drain pan. Is a defrost device for an air cooler, which rises to the opposite side of the drain pan, flows toward the cooling coil, and melts frost adhering to the cooling coil . 2. The defroster for an air cooler according to claim 1, wherein the casing has an air introduction part and an air discharge part, and the air introduction part and the air discharge part are each provided with a damper that closes at the time of defrosting. apparatus.

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