JP2007263419A - Exhaust heat recovering system from industrial waste water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust heat recovering system capable of recovering the heat supplied from the waste water with a simple system, and easily utilizing the same. <P>SOLUTION: In the system 1 for recovering exhaust heat from the waste water, comprising a first heat exchanger 2 exchanging heat between the waste water of high temperature H1 and circulated water W(c) of a temperature lower than the waste water, a second heat exchanger 5 to which the heated circulated water W(h) discharged from the first heat exchanger 2 passes, and a heat utilizing means 6 utilizing the heat obtained from the second heat exchanger 5, the cooled circulated water W(c) discharged from the second heat exchanger is distributed to the first heat exchanger 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a system for recovering waste heat from production wastewater, and more particularly to a waste heat recovery system from wastewater that is effectively used by recovering waste heat from production wastewater before being discharged into public sewage.

  A large amount of high temperature organic wastewater such as raw materials and container washing water is generated from factories, particularly factories that produce food and drink. The waste water is diluted with well water and the like, then subjected to biological waste water treatment and discharged into public sewage. Below, the beer factory will be described as an example of the prior art for discharging such waste water into public sewage.

A schematic piping diagram for the treatment of production wastewater in a conventional beer factory is shown in FIG. 7a. As shown in FIG. 7a, the production wastewater H discharged from the production process 101 of the beer factory is discharged into public sewage through a wastewater treatment facility 102 that removes organic matter / phosphorus and nitrogen. The production wastewater H flowing into the wastewater treatment facility 102 has a flow rate of about 6,000 m ³ / day and a temperature of about 40 to 43 ° C. in the summer. Before the waste water H flows into the waste water treatment facility 102, the well water J is added and the temperature of the waste water is diluted so that the temperature of the waste water becomes 40 ° C. or less.

  FIG. 7b shows a schematic piping diagram of means for utilizing heat in the manufacturing process of a conventional beer factory. FIG. 7 b shows a can warmer 103, a boiler facility 104, and a washing water heating facility 105. The can warmer 103 is a device that sprays hot water using water vapor as a heat source to a can product filled with the contents so that the surface of the can does not condense before being packed in a box.

  Water vapor used for the can warmer 103 is obtained from the boiler equipment 104. The water vapor is generated when pure water stored in the pure water tank 106 is heated by the boiler 108 via the boiler water supply tank 107. The generated water vapor is put into a hot water tank in which water for watering the can warmer 103 is stored, and the water temperature is raised. The warm water for the can warmer thus obtained is sprinkled on the can product. The amount of heat used to generate hot water for the can warmer 103 is about 23,600 GJ / year.

  Further, the water vapor generated by the boiler 108 is used for the process 109 or the cleaning water heating equipment 105 that requires other heat. The cleaning water heating facility 105 exchanges heat between the cleaning water stored in the cleaning water tank 110 with the water vapor generated by the boiler 108 using the heat exchanger 111 and stores the heat in the cleaning hot water tank 112.

  As a technique for utilizing exhaust heat, in Patent Document 1, a water-permeable pipe is arranged in the foundation of a commercial kiln furnace body such as a charcoal kiln or a food heating stone kiln, and hot water is transferred by heat transfer from the furnace body. It is disclosed that the obtained hot water is used for thermal treatment such as bathing, sauna bath or hot sand bath. Patent Document 2 proposes recovering heat from hot waste water of a domestic bath and using it in a hot water supply device.

JP-A-2005-55099 JP-A-57-55332

  High-temperature production wastewater is discharged in large quantities in factories, particularly in factories that produce food and drink. The production wastewater is purified by a biological wastewater treatment facility and discharged into public sewage. In the summer, the temperature of production wastewater flowing into the treatment facility may exceed 40 ° C. If the temperature change of the wastewater flowing into the treatment facility is large, stable biological treatment ability cannot be maintained. In addition, when extremely high temperature wastewater flows in, there is a risk that the activity of the organisms may be reduced. Therefore, before biological treatment is performed, the temperature of the waste water is diluted with well water so that the temperature of the waste water is 40 ° C. or less.

  On the other hand, factory production processes include processes that require a heat source, such as can warmers, bottle warmers, washing water heating equipment, boiler equipment, carbon dioxide vaporizers, and nitrogen gas evaporators. In recent years, saving energy in factories and the like has been emphasized. If the thermal energy of the production wastewater (warm water) discharged in large quantities is recovered and can be used for a process that requires a heat source, the energy is saved. However, since the supply of heat obtained from the waste water and the demand for heat necessary for the production process are not always balanced between the demand and the supply, it is difficult to efficiently recover the heat. Moreover, when the temperature of production waste water is not so high as about 60 degreeC, the use using the heat is limited.

  Therefore, an object of the present invention is to provide an exhaust heat recovery system that can recover the amount of heat held by the waste water with a simple system and that can be used effectively.

  The exhaust heat recovery system of the present invention (Claim 1) includes a first heat exchanger that performs heat exchange between waste water and circulating water having a temperature lower than that of the waste water, and heating that is discharged from the first heat exchanger. An exhaust heat recovery system from waste water, comprising: a second heat exchanger through which the circulated water is passed, and a heat utilization means utilizing the heat obtained from the second heat exchanger. Cooled circulating water discharged from the heat exchanger is passed through the first heat exchanger.

Such an exhaust heat recovery system includes a high-temperature tank that stores heated circulating water discharged from the first heat exchanger, and a low-temperature tank that stores cooled circulating water discharged from the second heat exchanger. (Claim 2). Moreover, it is preferable to provide the drainage tank which stores wastewater (Claim 3), and when it has two or more drainage tanks, it is preferable that the 1st heat exchanger is arrange | positioned for every drainage tank ( Claim 4). This is because, for example, in the case of a beer factory, the waste water is various high temperature waste water in the beer manufacturing process, and the waste water is stored in separate storage tanks / tanks, and a first heat exchanger is arranged for each storage tank / tank. It means that
Further, it is preferable that the heat utilization means is at least one means selected from a can warmer, a bottle warmer, a washing water heating facility, a boiler facility, a carbon dioxide evaporator and a nitrogen gas evaporator.
Furthermore, the thing provided with the waste water treatment means which processes the cooled waste_water | drain discharged | emitted from a 1st heat exchanger is preferable (Claim 6).

The exhaust heat recovery system of the present invention (Claim 1) is a simple system in which circulating water is passed through two heat exchangers (first heat exchanger and second heat exchanger) and circulated. In addition to being able to recover the exhaust heat and effectively use it as thermal energy, it can also recover the cool heat generated from the production process and cool the drainage and the like. That is, by bringing circulating water as a heat medium into contact with each facility (each process) in the factory, warm and cold generated in the production process can be comprehensively effectively used as heat energy.
Further, the exhaust heat recovery system of the present invention (Claim 2) includes a high-temperature tank for storing heated circulating water discharged from the first heat exchanger, and a cooled exhaust discharged from the second heat exchanger. And a low-temperature tank for storing circulating water. Circulating water whose temperature has been increased by heat exchange with high temperature wastewater is stored in the high temperature tank, so when the heat utilization means is stopped, the waste heat can be stored by storing the circulating water in the high temperature tank. it can. In the second heat exchanger, heat is exchanged between the circulating water and the heat utilization means. Circulating water whose temperature has dropped due to the heat exchange is stored in a low temperature tank. Therefore, when high temperature waste water is not discharged, it is stored in the low temperature tank as circulating water for cooling high temperature waste water.
In this way, the heat required for the heat utilization means and the drainage can be stored in the high and low temperature tanks using the circulating water as a heat medium, so that heat is not wasted and energy is saved. Furthermore, even if the heat supply by the waste water and the heat demand by the heat utilization means are not performed at the same time, the stored heat can be taken out from the tank and used as circulating water when necessary.

Heat exchange may be performed by continuously passing wastewater through the first heat exchanger, but heat exchange is performed after the wastewater is temporarily stored by providing a drainage tank, that is, the first heat exchange in a batch type. A system for passing water through the vessel is useful in terms of stability and efficiency (Claim 3). If a drainage tank is installed, even if hot wastewater is concentrated and discharged in a short time, it can be temporarily stored in the drainage tank and taken out as needed. This is because processing such as passing water through can be performed.
In the case where a plurality of drainage tanks are provided, a first heat exchanger is arranged for each tank. For example, when the waste water is various high temperature waste water in the beer manufacturing process, the waste water is stored in separate tanks, and the first heat exchanger is arranged for each tank, one waste water of the same property is used. Since it is stored in the tank, in the case of wastewater with a small amount of floating sludge, there is little pressure loss in the heat exchanger, so that the cross-sectional area of the flow path for heat exchange in the heat exchanger can be reduced. On the other hand, in the case of wastewater containing a lot of sludge and the like, the pressure loss in the heat exchanger is likely to increase, so measures such as reducing the pressure loss can be taken. Therefore, exhaust heat can be efficiently recovered for each drainage.
When the heat utilization means is at least one means selected from a can warmer, a bottle warmer, a washing water heating facility, a boiler facility, a carbon dioxide evaporator and a nitrogen gas evaporator (Claim 5), The heat of about 60 ° C., which is exhausted together with the waste water, can be effectively utilized, and the temperature of the waste water can be lowered. Further, by effectively utilizing the exhaust heat, for example, water vapor used for generating hot water for conventional can warmers can be significantly reduced.
Furthermore, when the waste water treatment means for treating the cooled waste water discharged from the first heat exchanger is provided (Claim 6), the temperature of the waste water flowing into the waste water treatment facility is changed to a large amount of temperature-diluted water or the like. Even if it is not used and adjusted, it can be stabilized. Therefore, the process of temperature dilution water can be omitted, the wastewater treatment capacity of the facility is improved and stabilized, and the use of temperature dilution water (well water) used to cool the wastewater can be eliminated or greatly reduced. .

  Next, the exhaust heat recovery system of the present invention will be described with reference to the drawings. 1 and 2 are schematic piping diagrams showing an exhaust heat recovery system of the present invention, FIG. 3 is a schematic piping diagram showing an embodiment of waste water treatment means related to the present invention, and FIG. 4 is an implementation of heat utilization means related to the present invention. FIG. 5 is a piping diagram showing another embodiment of the exhaust heat recovery system of the present invention, and FIG. 6 is a piping diagram showing still another embodiment of the waste water recovery system of the present invention.

In FIG. 1, the schematic of the waste heat recovery system 1 from the waste_water | drain based on Claim 1 of this invention is shown. The exhaust heat recovery system 1 includes a first heat exchanger 2 that performs heat exchange between the high temperature waste water H1 and the circulating water W (c) that is cooler than the waste water, and the first heat exchanger 2 that discharges heat. A second heat exchanger 5 through which the heated circulating water W (h) to be passed is passed, and heat utilization means 6 that uses the heat E ′ obtained by the second heat exchanger 5. In this system, the circulating water W (c) cooled by the second heat exchanger 5 is passed through the first heat exchanger 2.
In the present invention, the circulating water W (c) cooled by the second heat exchanger 5 can be reused as a cooling medium for cooling the high temperature waste water H1. The circulating water W (c) cooled by the second heat exchanger 5 may be supplied to the first heat exchanger 2 as it is, or once stored in a tank and then supplied to the first heat exchanger 2. You may supply (refer FIG. 2). In any case, since the circulating water W is circulated, there is no need to prepare the circulating water W (c) separately, and the heat and cold generated in the production process are recovered very easily and economically as heat energy. It is a system that can be used effectively.

The drainage H1 is drainage from a beer factory, a food factory, or the like, and may contain organic matter, phosphorus, nitrogen, or the like. Although the liquid temperature of H1 of waste water is not particularly limited, the present invention recovers waste heat from waste water by performing heat exchange between the waste water and circulating water having a temperature lower than that of the waste water. More specifically, it is preferably 50 ° C. or higher, more preferably 60 ° C. or higher. The upper limit of the liquid temperature is not particularly limited, but is 95 ° C. or less, preferably 90 ° C. or less from the viewpoint of safety.
The circulating water W (W (c), W (h)) is not limited to water as long as it can be used as a heat medium, and an antifreeze can also be used. Preferably used. The liquid temperature of the circulating water W (c) is not particularly limited as long as it is lower than the waste water H1, but from the viewpoint of waste water treatment, the waste water H1 may be cooled to 40 ° C. or less by the first heat exchanger 2. preferable. Therefore, the liquid temperature of the circulating water W (c) is 40 ° C. or less, preferably 30 ° C. or less, more preferably about 20 ° C.

  As the first heat exchanger 2, a spiral heat exchanger suitable for heat exchange of slurry is used in the case of waste water containing a large amount of sludge. As the spiral heat exchanger, there is one in which two metal plates are wound in a spiral shape to form two flow paths. In addition to the spiral heat exchanger, a single-channel heat exchanger such as a multi-tube type may be used. In the case of drainage that does not contain sludge, a plate heat exchanger or the like may be used. Although the second heat exchanger 5 is a plate heat exchanger, a spiral heat exchanger or a multi-tube heat exchanger can be used in the same manner as the first heat exchanger 2.

  The heat utilization means 6 is means for obtaining heat E ′ by exchanging heat with the circulating water W (h) by the second heat exchanger 5 and using it for the production process of the factory. That is, the heat utilization means 6 is a means for utilizing the heat E ′ obtained by the second heat exchanger 5 as a heat source. Any means that requires a heat source is not particularly limited, and specific examples include can warmers, bottle warmers, washing water heating equipment, boiler equipment, carbon dioxide gas evaporators, nitrogen gas evaporators, and the like. In addition, the mode of the heat medium E of the heat utilization means 6 supplied to the second heat exchanger is not limited to the state of liquid, gas, etc. depending on the preferred mode of the heat source of the heat utilization means 6, but the heat transfer efficiency From the viewpoint of the above, a liquid can be preferably used. In the above can warmer and bottle warmer, the shower water E1 is heated to obtain hot water E1 ′. In the above boiler equipment, the pure water E2 is heated to obtain boiler hot water E2 ′. In the washing water heating equipment, The washing water E3 is heated to obtain a washing warm water E3 ′ (see FIG. 4).

  FIG. 2 shows a schematic diagram of a waste heat recovery system 1 from waste water according to claim 2 of the present invention. The exhaust heat recovery system 1 includes a first heat exchanger 2 that exchanges heat between the high temperature waste water H1 and the circulating water W (c), and the circulating water W ( The high-temperature tank 4 storing h), the second heat exchanger 5 in which the circulating water W (h) stored in the high-temperature tank 4 is heat-exchanged, and the heat obtained by the second heat exchanger 5 are used. And a low-temperature tank 7 for storing the circulating water W (c) heat-exchanged by the second heat exchanger 5. FIG. 2 also shows waste water treatment means 3 for treating the waste water H1 'heat-exchanged by the first heat exchanger 2 according to claim 6 of the present invention.

  The high temperature tank 4 and the low temperature tank 7 are kept warm by a heat insulating material. The capacity of each of the high temperature tank 4 and the low temperature tank 7 can increase the amount of heat stored as the capacity increases, but the amount of heat supplied from the waste water H1 and the demand for heat used by the heat utilization means 6 can be increased. It is preferably designed according to the quantity.

  A state in which the exhaust heat recovery system 1 thus formed operates will be described with reference to FIG. High temperature waste water H1 discharged from a factory or the like is passed through the first heat exchanger 2 by a drain pump P1. On the other hand, the circulating water W (c) stored in the low temperature tank 7 is passed through the first heat exchanger 2 by the first pump P2. The exhaust heat H1 and the circulating water W (c) are heat-exchanged by the first heat exchanger 2, the temperature of the waste water H1 is lowered, and the temperature of the circulating water W (c) is raised. The circulating water W (h) whose temperature has risen is stored in the high temperature tank 4. The circulating water W (h) stored in the high temperature tank 4 is passed through the second heat exchanger 5 by the second pump P3. In the second heat exchanger 5, the circulating water W (h) and the heat utilization means 6 exchange heat, and the temperature of the circulating water W (h) decreases. The circulating water W (c) whose temperature has dropped is sent to the low temperature tank 7 and stored.

As described above, the exhaust heat recovery system 1 of FIG. 1 can store heat separately on the drain H1 side and the heat utilization means 6 side. That is, when the heat utilization means 6 is stopped, the waste water is stored in the high-temperature tank 4 by storing the circulating water W (h) heat-exchanged with the high-temperature waste water H1 in the first heat exchanger 2. Can do. When the high temperature waste water H1 is not discharged, the circulating water W (c) whose temperature has been lowered by the second heat exchanger 5 is stored in the low temperature tank 7 for cooling the high temperature waste water H1. Therefore, energy is saved because heat is not exhausted wastefully. Moreover, since temperature dilution water, such as well water for cooling waste water, is not used wastefully, it becomes environmental protection.
Furthermore, even if the amount of heat supplied by the waste water H1 and the amount of heat demanded by the heat utilization means 6 do not match, the stored heat can be taken out from the tank and used when necessary.
The drain pump P1 and the first pump P2 can be controlled so as to operate in cooperation. For example, the temperature of the waste water (or the temperature of the waste water stored in the storage tank 8 storing the waste water H1) is high, specifically, the temperature exceeds 60 ° C., and the circulating water stored in the low temperature tank A control that enables the drainage pump P1 and the first pump P2 to operate together when the amount of W (c) is equal to or higher than a certain level can be exemplified.

The wastewater treatment means 3 adjusts the pH and removes organic substances, phosphorus and nitrogen so that the wastewater H1 can be discharged into public sewage. An embodiment of the waste water treatment means 3 will be described with reference to FIG. The wastewater treatment means 3 includes a storage tank 8 that stores the wastewater H1 and a wastewater treatment facility 9 for biologically treating the wastewater H1 ′ cooled by the first heat exchanger 2.
In the wastewater treatment facility 9, the wastewater H1 ′ is purified by biological treatment and discharged into public sewage.

  When the high-temperature waste water H1 is heat-exchanged in the first heat exchanger 2 and the temperature is lowered, the temperature of the waste water flowing in the subsequent biological treatment process of the waste water is also stabilized. Especially in summer, since the inflow of waste water whose temperature has risen excessively can be prevented, the treatment capacity of the waste water treatment facility 9 using microorganisms is stabilized.

  An embodiment of the heat utilization means 6 will be described with reference to FIG. The heat utilization means 6 includes a can warmer 10, a boiler facility 11, and a washing water heating facility 12. The can warmer 10 is a device that prevents the surface of the can from condensing before being boxed by sprinkling warm water of about 25 to 40 ° C. to the can product filled with the contents. In the can warmer 10, the shower water E1 is sent to the second heat exchanger 5 by the shower pump P4, is heat-exchanged with the circulating water W (h) and warmed (E1 '), and is sprayed onto the can product. The can product is heated to about 20 ° C. to prevent condensation on the can surface.

The boiler facility 11 includes a pure water tank 13 in which pure water E2 is stored, a boiler water supply pump P5 that sends the pure water E2 of the pure water tank 13 to the second heat exchanger 5, and a second heat exchanger 5. The boiler feed water tank 14 stores the pure water E2 ′ heat-exchanged with the circulating water W (h) and preheated, and the boiler 15 that heats the pure water in the boiler feed water tank 14 to generate water vapor. The steam generated by the boiler 15 is sent to another production process 21 or the like. In the boiler plant 11, pure water E ₂ by circulating water W (h), are savings is preheated to 30 to 60 ° C..
The washing water heating equipment 12 includes a washing water tank 16 in which washing water E3 is stored, a washing water pump P6 that sends the washing water E3 of the washing water tank 16 to the second heat exchanger 5, and a second heat exchanger. 5 includes a washing hot water tank 17 for storing washing water E3 ′ heat-exchanged with circulating water W (h) and preheated. In the washing water heating equipment 12, the washing water E3 is preheated and stored in the same manner as the pure water E2 in the boiler equipment 11 described above.

  In this way, in the can warmer 10, the shower water E1 can be heated by the second heat exchanger 5 and sprinkled as it is, so that it is possible to eliminate the conventionally required shower water heating equipment, and the heating equipment It can save energy because it can reduce the energy required for. Moreover, since the boiler equipment 11 or the washing water heating equipment 12 preliminarily warms and stores pure water, washing water, or the like, energy, equipment, etc. in the subsequent heating process by the boiler 15 can be reduced. Can save energy.

  FIG. 5 is a piping diagram showing an embodiment in which the exhaust heat recovery system 1 is used in a beer factory. The exhaust heat recovery system 20 shown in FIG. 5 includes a storage tank 8 and a waste water treatment facility 9 as the waste water treatment means 3 of the exhaust heat recovery system 1, a can warmer 10 as a heat utilization means 6, boiler equipment 11, and washing water heating. Equipment 12. In addition, the same code | symbol is attached | subjected to the location which overlaps with the above-mentioned description, and the description is abbreviate | omitted.

The exhaust heat recovery system 20 will be described focusing on the route through which the production wastewater flows. Production wastewater H1 from the preparation process flows into the storage tank 8. The waste water H1 at this time has a flow rate of about 1,000 m ³ / day, and its temperature is about 65 ° C. The temperature of the waste water H1 stored in the storage tank 8 is also about 65 ° C. From the storage tank 8, the production wastewater H1 is passed through the first heat exchanger 2 by the drainage pump P1. The flow rate of the drain pump P1 is about 50 m ³ / h.

The production wastewater H1 is heat-exchanged with the circulating water W (c) in the first heat exchanger 2 and cooled to about 43 ° C. The cooled production wastewater H1 ′ is mixed with the wastewater H2 from another process in the middle of the route toward the wastewater treatment facility 9. The flow rate of the waste water H2 is about 5,000 m ³ / day, and the temperature is about 35 to 45 ° C. The mixed waste water H (H1 + H2) has a flow rate of about 6,000 m ³ / day and a temperature of about 36 to 40 ° C. in the summer, and flows into the waste water treatment facility 9.

In the wastewater treatment facility 9, anaerobic wastewater treatment and aerobic wastewater treatment are performed, and after the wastewater is purified, it is discharged into public sewage. The discharge flow rate is about 6,000 m ³ / day, and the temperature is 40 ° C. or less.

  Thus, in the waste heat recovery system 20, since the waste water temperature flowing into the waste water treatment facility 9 is about 36 to 40 ° C., well water J (see FIG. 7) is not added as temperature dilution water as in the prior art. May be. In particular, in summer, the waste water H having an excessively high temperature does not flow into the waste water treatment facility 9, so that waste water treatment using stable organisms can be performed.

Next, the exhaust heat recovery system 20 will be described focusing on the route through which the circulating water flows. Circulating water W (c) is stored in the low temperature tank 7. The volume of the low temperature tank 7 is about 100 m ³ , and the temperature of the stored circulating water W (c) is about 37 ° C. The circulating water W (c) stored in the low temperature tank 7 is passed through the first heat exchanger 2 by the first pump P2. The flow rate of the first pump P2 is about 45 m ³ / h. In addition, the 1st heat exchanger valve | bulb 26 is provided in the inlet side of the 1st heat exchanger 2, and the flow of the circulating water W (c) which flows into the 1st heat exchanger 2 can be adjusted (FIG. 6). reference). In the first heat exchanger 2, the circulating water W (c) is heat-exchanged with the waste water H 1, warmed to about 60 ° C. (W (h)), and stored in the high-temperature tank 4. The volume of the high temperature tank 4 is about 100 m ³ .

The circulating water W (h) stored in the high temperature tank 4 is passed through the second heat exchanger 5 by the second pump P3 at a flow rate of about 80 m ³ / h. The second heat exchanger 5 is composed of a plurality of heat exchangers for the can warmer 10, the boiler equipment 11, the washing water heating equipment 12, and the like. The circulating water W (h) is deprived of heat by the heat utilization means 6 in the second heat exchanger 5 to a temperature of about 37 ° C. and returned to the low temperature tank 7 again. A second heat exchanger valve 18 is provided on the inlet side of the second heat exchanger 5 so that the flow of the circulating water W (h) flowing into the second heat exchanger 5 can be adjusted. Further, a bypass is provided between the high-temperature tank 7 and the low-temperature tank 4, and a bypass valve 19 for opening and closing the bypass is provided.

In the can warmer 10, hot water having a temperature of about 34 ° C. is obtained by the four second heat exchangers 5, 5, 5, 5, and the hot water is sprinkled on the can product by the shower pump P 4. In the boiler facility 11, pure water having a temperature of about 20 ° C. stored in the pure water tank 13 is passed through the second heat exchanger 5 by a boiler water replenishing pump P5, and boiler water is supplied as hot water having a temperature of about 55 ° C. It is stored in the tank 14. Further, the wash water having a temperature of about 20 ° C. stored in the wash water tank 16 is passed through the second heat exchanger 5 by the wash water pump P6 and stored in the wash hot water tank 17 as hot water having a temperature of about 59 ° C. The
The second pump P3 is operable when the liquid temperature in the high temperature tank 4 is equal to or higher than a certain temperature (specifically, 50 ° C. or higher, preferably 55 ° C. or higher) and the liquid amount is equal to or higher than a certain level. It is preferable to control. The shower pump P4 is turned on when the can warmer 10 is operating. In the boiler water supply pump P5, when the boiler feed water tank 14 of the boiler facility 11 is less than a certain amount of liquid, and the wash water pump P6, the wash warm water tank 17 of the wash water heating facility 12 is at a certain amount of liquid. Operates when: Therefore, it is preferable to control so that the second pump P3 operates when any of the shower pump P4, the boiler water supply pump P5, or the washing water pump P6 is operated.

  Thus, according to the waste heat recovery system 20, the heat of the waste water H1 can be recovered and the discharge temperature to the public sewage can be 40 ° C. or lower. And since the warm water used for the can warmer 10, the boiler equipment 11, and the washing water heating equipment 12 or the warm water for the preheating of a boiler can be obtained with the collect | recovered heat, it is energy-saving. With this exhaust heat recovery system 20, the amount of water vapor used to generate hot water for conventional can warmers could be reduced by about 7000 t / year.

FIG. 6 is a piping diagram showing still another embodiment of the exhaust heat recovery system of the present invention. Since the exhaust heat recovery system 22 shown in FIG. 6 is substantially the same as the exhaust heat recovery system 20 described above, the same parts are denoted by the same reference numerals and description thereof is omitted. The heat utilization means 6 of the exhaust heat recovery system 22 includes, in addition to the can warmer 10, a bottle warmer 10a, a carbon dioxide / nitrogen gas evaporator 10b, and other equipment 10c. Similar to the can warmer 10, the bottle warmer 10a is a device that sprays warm water on the bottle product filled with the contents and prevents condensation on the surface of the bottle when a label is applied. The carbon dioxide / nitrogen gas evaporator 10b is an apparatus for evaporating liquefied carbon dioxide and liquefied nitrogen in order to supply carbon dioxide / nitrogen gas to the beer production process.
The other equipment 10c includes a saccharification starch storage tank temperature holding equipment, a beer production process tank cleaning equipment, a heating air conditioner, a floor heating device, or a dehumidifier regenerative heater.

  When beer, sparkling liquor, etc. are produced at a beer factory at about 280,000 KL / year, the amount of heat required for the can warmer 10 is about 23,600 GJ / year. The bottle warmer 10a is about 1,600 GJ / year, the carbon dioxide / nitrogen gas evaporator 10b is about 4,800 GJ / year, the boiler equipment 11 is about 3,800 GJ / year, and the washing water heating equipment 12 is about About 7,300 GJ / year. The total amount of heat used is about 41,100 GJ / year.

In addition, the waste water treatment facility 3 of the heat recovery system 22 includes a fermentation waste water recovery tank 23, a filtered waste water recovery tank 24, and a barrel waste water recovery tank 25 in addition to the charged waste water storage tank 8. The charged waste water reservoir 8 volume at 40 m ^3, the drainage of the average 65 ° C. is about 200,000M ³ wastewater per year. Fermentation waste water recovery tank 23 has a volume of 50 m ³ , and an average of about 25,000 m ^{3 of} waste water with an average temperature of about 75 ° C. is drained. The filtered waste water collection tank 24 has a volume of 50 m ³ , and about 40,000 m ^{3 of} waste water with an average of about 75 ° C. is drained annually. The barreled waste warm water recovery tank 25 has a volume of 10 m ³ , and drainage at an average of about 80 ° C. is drained by about 27,000 m ³ per year. Further, charged drainage tank 8, the flow rate of the fermentation waste hot water recovery tank 23 and is connected to a filtered exhaust hot water recovery tank 24 drainage pump P1 are each 50 m 3 / ^h, the drainage pump P1 of Tarutsume waste hot water recovery tank 25 The flow rate is 7 m ³ / h.

  Thus, the amount of drainage, temperature, or nature of the drainage varies depending on the process. Since wastewater of the same nature is stored in one tank, if there is little sludge floating, there is little pressure loss in the heat exchanger, so the cross-sectional area of the channel for heat exchange in the heat exchanger Can be reduced. On the other hand, in the case of wastewater containing a lot of sludge and the like, the pressure loss in the heat exchanger is likely to increase, so measures such as reducing the pressure loss can be taken. Therefore, exhaust heat can be efficiently recovered for each drainage. Further, since the wastewater is once stored in the storage tank / tank, even if high temperature wastewater is concentrated, it can be stored in the storage tank / tank and taken out as necessary. In this case, the effect of insulating the tank is high. Since the waste water can be passed through the biological treatment facility after the temperature of the waste water is reliably lowered, the system is stable.

  The wastewater stored in the four tanks reaches a water temperature of 43 ° C. by the first heat exchangers 5, 5, 5, 5 and flows to the wastewater treatment facility 9 (see FIG. 5). The amount of heat recovered at that time is about 18,400 GJ / year in the charged waste water storage tank 8, about 3,400 GJ / year in the fermentation waste water recovery tank 23, and about 5,400 GJ in the filtered waste water recovery tank 24. / Year, about 4,200 GJ / year in the barreled waste water recovery tank 25. The total amount of recovered heat is about 31,400 GJ / year. Since the total amount of heat used is about 41,100 GJ / year, the waste water is reliably cooled and 76% of the heat used can be reduced.

In this exhaust heat recovery system 22, the circulating water W supplied from the high temperature tank 4 to the heat utilization means 6 and the circulating water W supplied from the low temperature tank 7 to the exhaust heat treatment means 3 are system-separated by the respective tanks. ing.
In such a case, it becomes easy to supply the circulating water W of the high-temperature tank 4 to other heat utilization means, or to supply the circulating water W of the low-temperature tank 7 to other waste heat treatment means, thereby simplifying the scale-up. It can be carried out.

FIG. 1 is a schematic piping diagram showing an exhaust heat recovery system of the present invention. FIG. 2 is a schematic piping diagram showing the exhaust heat recovery system of the present invention. FIG. 4 is a schematic piping diagram showing the waste water treatment means according to the present invention. FIG. 4 is a schematic piping diagram showing heat utilization means according to the present invention. FIG. 5 is a piping diagram showing another embodiment of the exhaust heat recovery system of the present invention. FIG. 6 is a piping diagram showing still another embodiment of the wastewater recovery system of the present invention. FIG. 7a is a schematic piping diagram of the treatment of production wastewater in a conventional beer factory, and FIG. 7b is a schematic piping diagram of a can warmer in the manufacturing process of a conventional beer factory.

Explanation of symbols

1 Waste heat recovery system from waste water 2 First heat exchanger 3 Waste water treatment means 4 High temperature tank 5 Second heat exchanger 6 Heat utilization means 7 Low temperature tank 8 Storage tank 10 Waste water treatment facility 10 Can warmer 10a Bottle warmer 10b Carbon dioxide gas Nitrogen gas evaporator 10c Other equipment 11 Boiler equipment 12 Washing water heating equipment 13 Pure water tank 14 Boiler feed water tank 15 Boiler 16 Washing water tank 17 Washing hot water tank 18 Second heat exchanger valve 19 Bypass valve 20 Waste heat recovery system 21 etc. Production process 22 Waste heat recovery system 23 Fermentation waste water tank 24 Filtration waste water recovery tank 25 Barrel waste water recovery tank 26 First heat exchanger valve P1 Drain pump P2 First pump P3 Second pump P4 Shower pump P5 Boiler Water supply pump P6 Wash water pump H Production waste water
E Heat utilization means water supplied to the second heat exchanger (shower water, boiler water, washing water, etc.)
W Circulating water J Well water

Claims (6)

  A first heat exchanger that performs heat exchange between the waste water and circulating water having a temperature lower than that of the waste water, and a second heat exchanger through which the heated circulating water discharged from the first heat exchanger is passed. And a waste heat recovery system from waste water comprising heat utilization means for utilizing the heat obtained from the second heat exchanger, wherein the cooled circulating water discharged from the second heat exchanger is An exhaust heat recovery system wherein water is passed through the first heat exchanger.   A high-temperature tank for storing the heated circulating water discharged from the first heat exchanger; and a low-temperature tank for storing the cooled circulating water discharged from the second heat exchanger; The exhaust heat recovery system according to claim 1, wherein the circulated water is passed through the first heat exchanger.   3. The exhaust heat recovery system according to claim 1, further comprising a drainage tank for storing drainage, wherein the wastewater stored in the drainage tank is passed through the first heat exchanger.   The exhaust heat recovery system according to claim 3, wherein a plurality of drain tanks are provided, and a first heat exchanger is arranged for each of the tanks.   The exhaust according to any one of claims 1 to 4, wherein the heat utilization means is at least one means selected from a can warmer, a bottle warmer, a washing water heating facility, a boiler facility, a carbon dioxide evaporator and a nitrogen gas evaporator. Heat recovery system.   The waste heat recovery system according to any one of claims 1 to 5, further comprising waste water treatment means for treating the cooled waste water discharged from the first heat exchanger.

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