TITLE OF THE INVENTION:
Heat recovery unit which utilizes heat from the discharged refrigerant of a compressor
FIELD OF THE INVENTION:
The present invention relates to an electromechanical unit which absorbs heat of the refrigerant, discharged from the compressor and uses this heat to increase the temperature of a medium which can be used further in a heated form.
BACKGROUND OF THE INVENTION:
Cooling is a process in which heat is removed from one source and moved to another source. Cooling is done in many places like household refrigerators, industrial freezers, cryogenics, air conditioners etc. Industrial freezers or coolers are usually big vessels which are used to cool various products for further use. Cooling of these products in such big vessels require the working of compressors with great capacity. Such compressors release a large quantity of heat which if dissipated in the atmosphere cause increase in the surrounding temperature thus contributing to global warming.
The dairy industry involves collecting milk from the suppliers and dispensing it to the consumers. Various dairies collect huge volumes of milk. This milk needs to be stored at lower temperature to protect it from souring. The quicker the milk is cooled after leaving the animal's body, the better remains its quality. So the collected milk is stored in bulk milk cooling tanks. These are large storage tanks for cooling and holding of milk at a low temperature. Such tanks are one of the most important equipment of dairy farm. They are generally made out of stainless steel and used to store raw milk. Usually condensing units are provided in such tanks which cool the milk to a very low temperature. While reducing the

temperature of such large quantities of milk, the refrigerants discharged have a high temperature. Heat can be recovered from such discharged refrigerants for further use.
Heat recovery is a method of salvaging a portion of the energy wasted by inefficient heating, venting or air conditioning systems. So heat recovery units are used which recover the heat from the discharged refrigerants and can be used for further processes in the industries. Heat recovery units harness some of the liberated heat and redirect this form of energy for more practical uses. Such heat recovery units are generally found in industries involving processes that require both heating and cooling. These heat recovery units are generally positioned in between the compressor and the condenser in the cooling systems, so that the heat energy which is released by the compressor wouldn't be wasted. This heat energy released can be used for various purposes like heating of water, heating of other substances used in further processes.
US Patent 5046325 describes a refrigerating circuit apparatus which includes a two stage compressor having an upper stage compressing cylinder and a lower stage compressing cylinder, a heat stage tank, an upper stage side variable opening expansion valve and a lower stage side variable opening expansion valve. The upper stage side variable opening expansion valve is controlled toward its closed position for executing a heat storing operation wherein heat is discharged from refrigerant to the heat storage tank. The upper stage side variable opening expansion valve is opened and the lower stage side variable opening expansion valve is closed for carrying out a defrosting operation. Heat stored in the heat storage tank is used in the defrosting operation for removing frost accumulated on an external heat-exchanger during the heating operation.
US Patent 6056829 discusses cleaning of a milk tank and storage facility for carrying out that method which includes rinsing the tank with cold water and washing the tank with a warm liquid. During rinsing, the tank is finally rinsed with substantially warmer water than

the cold water with which the tank is initially rinsed, the cold water being cold enough to remove milk residues such as proteins, from the milk tank. A dairy farm milk storage facility specifically adapted for carrying out this method is also described. Milk residues such as proteins are effectively rinsed away by the initially used cold water and no energy is consumed for heating this rinsing water. Subsequently the storage tank is gradually, evenly and very effectively pre-warmed by the final rinsing water prior to the washing stage, so less washing water is required to achieve the required washing temperature while thermal stresses occurring in the tank are kept low.
US Patent 7089880 discloses cooling milk in an automatic milking system in which example embodiments of the invention relate to methods and arrangements for cooling milk in a milk storage tank of an automatic milking system comprising (i) measuring an amount of extracted milk by a milk flow meter; (ii) determining a cooling need for milk stored or to be stored in the milk storage tank based on the amount of milk; (iii) measuring a quantity indicative of a temperature of an inner surface area of a bottom portion of the milk storage tank; and cooling the bottom portion of the milk storage tank in consecutive periods, such that each period of cooling (.tau.l, .tau.3) is followed by a respective period of non-cooling (.tau.2, .tau.4), wherein the duration of each period of cooling and/or non-cooling is based on the measured quantity indicative of the inner surface area temperature, and the cooling need. US Patent Application 20070204636 provides a heat pump, and in particular a heat pump for heating a hot water supply is provided with an improved defrost mode. The defrost mode is actuated to remove frost from an outdoor evaporator that may accumulate during cold weather operation. An algorithm for operation of the defrost mode is developed experimentally by seeking to maximize the heat transfer provided by the refrigerant. A heating system condition is experimentally related to the heat transfer capacity. One then maximizes the average heat transfer capacity to determine the optimum initiation point for

the defrost mode. Further, protections are included into the defrost mode. When the heat pump is utilized to heat hot water, methods are provided to prevent the water that remains in the heat exchanger from becoming unduly heated. In one method, the water pump may be periodically operated to move the water. In a second method, a control ensures the discharge pressure of the refrigerant leaving the compressor is reduced, and that the water pump is not stopped until that reduced temperature falls below a predetermined maximum. The temperature reduction is achieved through a dual control loop wherein a temperature that is too high results in a new desired discharge pressure. The control achieves the new desired pressure by controlling the expansion device. In another protection feature, as a control determines that the defrost mode is nearing its end, an evaporator fan is run to remove melted water from the evaporator coils, and also to ensure the refrigerant leaving the evaporator does not reach unduly high pressure or temperatures.
US Patent Application 20120151946 gives a method and a device for heat recovery on a vapour compression refrigeration system allowing to produce hot water, includes at least a first piping closed refrigerating circuit in which a refrigerant fluid circulates, a compressor, an evaporator, an expansion valve, a condenser and/or a heat recovery unit including a water inlet and a water outlet respectively connected to a second piping circuit comprising a circulating pump. At least one physical unit of the refrigerant fluid and/or water of the second piping circuit is determined. When the physical unit is lower than a predetermined threshold, condensing temperature is increased, and when said physical unit is greater than said predetermined threshold, condensing temperature is decreased to a minimum value. US Patent Application 2013213072 discloses a combined air-conditioning and hot-water supply system that, if a temperature that is set in a hot-water supply unit is higher than a temperature of refrigerant discharged from a compressor when the combined air-conditioning and hot-water supply system is in a heating operation cycle state, increases a target

condensing temperature of an outdoor unit above the target condensing temperature that has been set, and controls an opening degree of an indoor expansion device to be less than the opening degree that has been set, such that a heating load of an indoor unit is maintained constant.
WO 2013191373 relates to a cooling apparatus, comprising: a liquid storage tank which includes a refrigerating cycle having a compressor for compressing refrigerant by high-temperature and high pressure gas, a condenser for receiving the compressed refrigerant in a gasified state from the compressor so as to convert the same into a refrigerant in a liquefied state, a refrigerant pipe for circulating the refrigerant that is discharged from the condenser, and a heat exchange unit for carrying out heat exchange with an object, wherein the liquid storage tank temporarily stores the object, has an inlet pipe and an outlet pipe, and cools stored liquid by the heat exchange with the heat exchange unit; and a cooling efficiency increasing means which decreases the flowing speed of the liquid that is introduced into the liquid storage tank and increases the contact time with the heat exchange unit. The cooling apparatus is capable of continuously maintaining a desired cooling temperature due to excellent cooling efficiency even when new liquid is introduced into the liquid storage tank. EP 1298982 relates to a milking device for automatically milking animals, and in particular to the milk cooler (5) which is used to cool the collected milk before it is stored in a milk tank. The milk cooler (5) comprises a vessel filled with cooling liquid which is cooled by an evaporator (2) and a milk line which is cooled by the cooling liquid. According to the invention, the milk cooler (5) is provided with a storage vessel having means for storing the cooling liquid in the storage vessel during the internal cleaning of the milk line. The invention also relates to a method in which the milk which has been collected in a first milk vessel is pumped into the milk cooler, and in which, after a variable time, the milk from a following milk vessel is pumped into the milk cooler.

JP 2002147891 describes a hot-water supplier consisting of a refrigerating cycle capable of obtaining hot-water of 70°C or higher with a condensing pressure not higher than an allowable value. For achieving this a water supplying pipe (21) and a hot-water outputting pipe (22) are connected to a hot-water supplying heat exchanger (19) of the refrigerating cycle while a pressure type temperature regulating valve (30), detecting the pressure of refrigerant for the refrigerating cycle to control the flow rate of feed water, is provided in the water supplying pipe (21). The flow rate of feed water controlled by the pressure type temperature regulating valve (30), the heat transfer area, size, degree of super-cooling and the like of the hot-water supplying heat exchanger (10) are determined optimally to obtain hot-water, whose discharging temperature is higher than 70°C, with the compressing pressure lower than 2.15 MPa.
RU 02206215 discusses heating - refrigerating unit for farms which has two-section heat-exchanger with milk and cold-carrier channels, and hermetically sealed reservoir divided into sections by two group of alternating partitions. First group of partitions are mounted for forming through flow openings above lower edge. Second group of partitions have openings arranged below lower edge. Upper part of outer section defined by partition of second group of partitions is connected to water supply system and to cold-carrier channel inlet of heat-exchanger first section. Lower part of opposite outer section of reservoir is connected to cold-carrier channel outlet of heat-exchanger first section with warm water consumers and through heat level finishing device with warm water consumers for consuming warm water of different temperature levels. Cold-carrier channel of second heat-exchanger section is connected to natural cold receivers-accumulators and water-cooling finishing device. Level sensors mounted in releaser, milk and cold-carrier pumps and temperature sensors are electrically connected to control unit. Heating-refrigerating unit may be used in animal milk

farms and at milk processing enterprises. This invention reduces production and maintenance costs and increased efficiency in heat recovery.
DE 4134277 discloses a cooling system for a fluid, esp milk in a milking assembly, has a milk collection and delivery unit combined with a flow cooling principle. Pref. a programmable memory controls the final milk temp, according to operator needs. The milk temp, is held at a constant through the heat transfer through the infinitely variable controlled milk vol. as a milk pump connected to the milk delivery. Different cooling capacities are available according to the milk yield. The heat transfer is optimised by insulating the container for the cooling sole into separate hot and cold water zones. The milk is finally cooled in a double-walled milk tank. The cooling capacity is matched by simple refrigerating conversion of the plate size. For automatic cleaning, the milk collection unit also acts as a rinsing vessel. The system is compact, and gives a rapid cooling of the milk from the cows to storage temps., with low cost and little space requirements, independently of the actual milk yield.
FR 2602324 relates to a method and a device for controlling the temperature for liquids as they ferment by cooling the said liquid during fermentation and passing it into a container 1 by counter-current contact of the liquid on the external walls 6, 6a of an annular exchanger 5, the walls being cooled by a glycol and water solution 7 contained in the said exchanger 5, in which a primary "serpentine coil" circuit 8 connected to a refrigeration unit is submerged, the primary circuit 8 having direct pressure-reduction of the refrigerant fluid which it contains. CN 2698067 provides an equipment for storing milk, in particular relating to an ice water cold-storage type direct freezing milk container, comprising a container. The upper part of the container is provided with a milk inlet and the lower part of the container is provided with a milk outlet. The ice water cold-storage type direct freezing milk container is characterized in that the container comprises an inner container, a top cover and a dismountable inner

container case. A water cooling layer is positioned between the inner container and the inner container case. The interior of the inner container is provided with a blender and the bottom of the inner container is provided with a refrigerant distributor. The utility model has simple structure, good cooling effect and high cooling speed and saves energy and is not easy to form scale.
Indian Patent Application 2179/MUM/2011 provides a solar powered bulk milk cooler storage system which is a unit device useful for storage facility for milk which is kept under cool temperature for preservation to retain its freshness and nutrients facts for 1 day.
This way, a variety of bulk milk cooler systems are available in the prior art which have varied features. However, a low power consuming, low cost, highly efficient heat recovery system, which uses the heat recovered from refrigerant, discharged from compressor, to heat the required amount of water upto the required temperature for cleaning in place of the equipment is the need of the day.
OBJECT OF THE INVENTION:
The main object of the invention is to provide for a heat recovery unit which utilizes heat from the discharged refrigerant of a compressor which is used to heat the liquid medium kept in the heat recovery unit which is to be used further for cleaning in place purpose of the main unit/module.
Another object of the invention is to provide for a heat recovery unit which utilizes heat from the discharged refrigerant of a compressor which reduces the temperature of the discharged refrigerant in a cyclic process thereby increasing the efficiency of the condenser.
Still another object of the invention is to provide for a heat recovery unit which utilizes heat from the discharged refrigerant of a compressor which also cools down the milk in the bulk milk cooler due to lower compression ratio.

Yet another object of the invention is to provide for a heat recovery unit which utilizes heat from the discharged refrigerant of a compressor by which reverse heat transfer is avoided through solenoid valves which are connected to temperature controller.
A further object of the invention is to provide for a heat recovery unit which utilizes heat from the discharged refrigerant of a compressor using which the system consumes less electrical energy, lower time and limits environmental pollution caused by such systems on the basis of energy conservation principle.
SUMMARY OF THE INVENTION:
The present invention is a heat recovery unit which utilizes heat from the discharged refrigerant of a compressor after cooling the milk stored in huge vessels. This heat recovery unit is placed in between the compressor and the condenser so that the discharged refrigerant released from the compressor, goes to the heat recovery unit where the heat from the discharged refrigerant is transferred to the medium (liquid) present in the heat recovery unit such that refrigerant which reaches the condenser is at a low temperature and further condensed. The liquid medium which has been heated through this process is used for CEP purpose which is essential after every collection cycle of milk at low temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 gives the assembly drawing for heat recovery unit with stand. Fig. 2 gives the Piping & Instrumentation drawing of the system. Fig. 3 gives the Circuit diagram for the panel.
Fig. 4 gives the refrigerant flow diagram for normal refrigeration cycle. Fig. 5 gives the modified refrigeration cycle with heat recovery unit.

Fig. 6 gives the table depicting the costs of using conventional heating methods for CIP purposes.
DETAILED DESCRIPTION:
The nature of the invention and the manner in which it is performed is clearly described in the specification. The invention has various components and they are clearly described in the detailed description.
Bulk milk cooler systems are systems wherein raw milk is stored until the dispensing time. This raw milk deteriorates very fast at an ambient temperature. So it has to be cooled and stored at lower temperature until dispensing. Large tanks are used to store this huge quantity of milk at a low temperature. The milk in these tanks need to be cooled at a very fast rate to prevent its deterioration. So such tanks are provided with cooling systems for this purpose. A large amount of energy is used by these cooling systems which comprises of compressors and condensers. During the cooling process, energy is used in both steps, the process of compression of the refrigerant as well as its condensation.
In this process of cooling, the refrigerant initially arrives in the compressor at a low temperature as a low pressure gas. The compressor squeezes this refrigerant fluid which packs the molecules of the fluid closer together. The closer these molecules get, the higher becomes their energy and temperature. So the refrigerant leaves the compressor and enters into the condenser at a high temperature and high pressure in gaseous state, which when leaves the condenser is condensed to a liquid, under high pressure. The condenser uses a lot of energy for this purpose. When a heat recovery unit is placed in between the compressor and condenser, the heat from the high temperature high pressure gas, being released from the compressor, is absorbed by the unit so that the condenser has to consume lesser energy to condense this gas into a liquid under high pressure.

The present invention provides a heat recovery unit which utilizes heat from the discharged refrigerant of a compressor which works on the principle of increasing effective sub cooling of discharged refrigerant from compressor and using its latent heat to increase the product temperature. Conventionally, refrigerant is discharged from the compressor and is condensed in the condenser, back to its original liquid form. Initially, the refrigerant gets compressed in the compressor due to which it gets converted into a gas at high temperature and pressure. This gas is sent to the condenser for condensation under re-circulation process.
In the present invention, instead of sending this high temperature and high pressure gas from compressor to condenser, it is sent to the heat recovery unit from the compressor. So this high temperature, high pressure gas enters the heat recovery unit. This unit already contains water which is to be used for cleaning in place (CIP) purpose. The high temperature of the gas is used to heat this water. Thus in the above process, heat transfer occurs as a result of which the temperature of the discharged refrigerant is reduced relatively. So when the refrigerant enters the condenser for condensation, it is at a quiet reduced temperature due to which its work done is reduced considerably and its efficiency increases.
The heat recovery unit of the present invention is used in bulk milk cooler systems wherein the milk available is cooled down after a low compression ratio. The temperature of the milk goes down by continuous recirculation of the cooled refrigerant. This way, large amount of milk can be stored here until dispensing. Moreover, the heat when transferred to water present in the heat recovery unit, increases its temperature to the desired level which is optimum for CIP purpose.
Initially, the temperature of the milk is the ambient temperature which is around 35 C. During the cooling of this milk, the temperature and pressure of the discharged refrigerant is higher. As the temperature of the milk is gradually decreased (below 10°C), the temperature and pressure of the discharged refrigerant also decreases. When the temperature of the water

in the heat recovery unit reaches the required degrees, nearly 80°C, the temperature of the discharged refrigerant is lower. This discharged refrigerant at a lower temperature enters the heat recovery unit and may cause reverse heat transfer as the water in the heat recovery unit is at a higher temperature than the temperature of the entering refrigerant. This may lead to decrease of the overall efficiency of the refrigeration system and thus increase the overall cooling time. To overcome this drawback, the heat recovery unit of the present invention is provided with solenoid valves which are connected to temperature controller. When the water present in the unit achieves the predetermined temperature, the solenoid valves shut off due to which the incoming gas is bypassed from the unit and enters the condenser directly. These solenoid valves open only when the temperature of the water in the unit is below the predetermined point.
Fig. 1 gives the assembly drawing for heat recovery unit with stand. The heat recovery unit is made of stainless steel AISI - 304 having a capacity of 200 - 250 litres. The pre-polished surfaces of sheets are suitably protected during fabrication to avoid scratches, dents, marks, embedment of iron particles etc. It has a laser welded evaporator plate which ensures perfect distribution of refrigerant, higher heat transfer, short time and long life of equipment. The heat recovery unit is of 550 mm to 700 mm length and has an inner shell diameter of 700 mm. The solenoid valves used are EVR-15 valves with 16 mm ODF, connection - 5/8, NC/NO type of Danfoss make having AC/DC coil type. The Temperature transmitter is a PT-100 RTD, head type sensor having a range of 0-200 degree temperature of length 6 inch with XA inch adjustable BSP. The insulation used is high thermal efficient poly urethane (PUFF) of 40 kg/m3 density. The product inlet valve is of 15 mm to 25.4 mm diameter while the product outlet valve is a 1 XA inch ball valve made of stainless steel. The mounting stand used is a simple stand as shown in the fig. of 3 to 7 feet height. All the dimensions of the various values provided are in mm unless otherwise stated. All inside weld

joints are ground polished and 100% DP tested while the outer visible weld joints are ground and polished. Thus all the weld joints are ground finished.
Fig. 2 gives the piping and instrumentation drawing of the system which shows the compressor, the heat recovery unit and the condenser joined together to the bulk milk cooler.
Fig. 3 gives the circuit diagram for panel which shows the wiring for the heat recovery unit which includes the contactor of 230 Volts AC having a range of 8 Amp, a D/P MCB of 8 Amp, a temperature controller having a range of 0-100°C, solenoid valves 1 & 2 of normally closed type and solenoid valves 3 & 4 of normally open type.
Fig. 4 gives the diagram displaying the flow of the refrigerant through the parts of the system for a normal refrigeration cycle which route includes the compressor, the thermostatic expansion valve (the expansion valve bulb's positioning is mentioned in the fig.), sight glass, solenoid valve, filter, split valve, receiver and condenser.
Fig. 5 gives the diagram displaying the flow of refrigerant through the parts of the system for a modified refrigeration cycle which route includes a heat recovery unit between the compressor and the condenser. When the refrigerant travels through this route, it has been observed that the temperature of the water present in the heat recovery unit increases from ambient to 80°C and the solenoid valves actuate as per desired set points.
After every collection cycle of milk in the bulk milk cooler, it is necessary to do cleaning in place. Cleaning in place is the cleaning of the interior surfaces of the vessel without disassembling it. This process of cleaning is essential in the bulk milk coolers to avoid contamination, sticking of fatty material in the milk to the cooler valves and general cleaning of the cooler. This cleaning requires hot water at 65°C to 75°C for effective cleaning and removal of all kinds of impurities. Conventionally, this high temperature of water is achieved by using electric geezers/electric rods or through external wood fired system which are not found sufficient and efficient. These methods of heating water consume a large

amount of energy along with increasing pollution. Fig. 5 gives the table depicting the costs of using these conventional methods. It is observed that an electric geyser having a capacity of 50 litres consumes 24 KW power per day for a cleaning cycle. This means that it would use 720 KW power per month and 8640 KW power per year for cleaning the vessel. Taking the unit rate as INR 10, this cost is INR 240/day, INR 7200/month and INR 86400/year. Electrical Immersion rod too consumes 24 KW power per day, leading to 720 KW poer per month and 8640 KW power per year for CIP purposes. In this case too, taking unit rate as INR 10, this cost is INR 240/day, INR 7200/month and INR 86400/year. When wood is burned to heat the water, it is observed that almost 10 KG of wood is consumed per day, leading to 300 KG wood per month and 3600 KG wood per year. Taking the cost of wood as INR 6/KG, the cost comes to INR 60/day, INR 1800/month and INR 21600/year. Both these methods of conventionally heating water for CIP purposes prove to be costly. Moreover, these methods of heating water cause environmental pollution leading to global warming.
However it is observed that using the heat recovery unit of the present invention eliminates the requirement of extra power to get the desired temperature for CIP purposes as it works along with the condensing unit of the bulk milk cooler. Moreover, the use of the heat recovery unit also increases the over all efficiency of the bulk milk cooler and the cooling time is reduced by 30 minutes. This is because the discharged refrigerant when enters the condenser, is quiet cooler and so the condenser requires lesser power and time to condense the refrigerant. This way the cost of cooling as well as the cooling time is reduced and the environment doesn't get polluted.
The heat recovery unit of the present invention is highly advantageous as it operates quietly and so there isn't any need for noisy extractor fans. It has a provision of the outlet at the bottom so that water is drained completely out of the bulk milk cooler before the initiation of the next cycle. The heat recovery unit of the present invention has a provision of a 6 feet

stand which eliminates the need of a balance tank and extra pump thus saving the capital and running costs. As laser welded plates are present in this unit, large amount of heat can be transferred in shorter duration.
This heat recovery unit also benefits the cleaning process. The CEP process requires hot water at minimum 65°C for effective cleaning. The heat recovery unit provides 65°C to 80°C hot water which is at perfect temperature for CIP purposes. This heat recovery unit has a capacity of 200 - 250 litres due to which large volume of hot water, sufficient for a CIP cycle, is generated. This tank is designed such that adequate volume of water can be processed for CIP which is a limitation in conventionally used methods. This way the present invention is highly advantageous.
Although the preferred embodiment as well as the construction and use have been specifically described, it should be understood that variations in the preferred embodiment could be achieved by a person skilled in the art without departing from the spirit of the invention. The invention has been described with reference to specific embodiments which are merely illustrative and not intended to limit the scope of the invention as defined in the claims.

We claim,
1. Heat recovery unit which utilizes heat from the discharged refrigerant of a compressor which increases the effective sub cooling of the discharged refrigerant from the compressor and uses its latent heat to increase the product temperature which product can be used for cleaning purposes.
2. The heat recovery unit which utilizes heat from the discharged refrigerant of a compressor as claimed in claim 1 wherein the heat recovery unit is placed in between the compressor and the condenser of the cooling system.
3. The heat recovery unit which utilizes heat from the discharged refrigerant of a compressor as claimed in claim 2 wherein the compressed refrigerant discharged from the compressor, which is at a high temperature and pressure, enters the heat recovery unit which already contains cleaning material, preferably water, which is to be heated.
4. The heat recovery unit which utilizes heat from the discharged refrigerant of a compressor as claimed in claim 3 wherein the heat recovery unit has a capacity of holding 200 to 250 litres of cleaning material.
5. The heat recovery unit which utilizes heat from the discharged refrigerant of a compressor as claimed in claim 4 wherein the heat of the discharged refrigerant gas is transferred to the cleaning material present in the heat recovery unit through laser welded evaporator plate which ensures perfect distribution of refrigerant, higher heat transfer, short time and long life of equipment.
6. The heat recovery unit which utilizes heat from the discharged refrigerant of a compressor as claimed in claim 5 wherein due to the heat transfer, the temperature of the cleaning material rises between 65°C to 80°C which is the desired temperature for the cleaning purpose such that no external heating is required to achieve this temperature along with reducing the temperature of the discharged refrigerant such

that the condenser consumes lesser power and time to condense the already cooled refrigerant.
7. The heat recovery unit which utilizes heat from the discharged refrigerant of a compressor as claimed in claim 6 wherein chances of reverse heat transfer- are eliminated through the presence of solenoid valves which are connected to the temperature controller such that when the material present in the unit achieves the predetermined temperature, the solenoid valves shut off due to which the incoming gas is bypassed from the unit and enters the condenser directly wherein these solenoid valves open only when the temperature of the water in the unit is below the predetermined point.
8. The heat recovery unit which utilizes heat from the discharged refrigerant of a compressor as claimed in claim 7 wherein the heat recovery unit is provided with a 3 feet to 7 feet stand which eliminates the need of balance tank and extra pump for transfer of the cleaning material in the vessel to be cleaned.
9. The heat recovery unit which utilizes heat from the discharged refrigerant of a compressor as claimed in claim 8 wherein the vessel to be cleaned is provided with an outlet at the bottom to drain off all the cleaning material after the cleaning process.
10. The heat recovery unit which utilizes heat from the discharged refrigerant of a compressor substantially herein described with reference to the foregoing description and drawings.