Steam condensate heat energy and water multi-stage recovery and utilization system

Abstract

This utility model belongs to the field of milk powder processing technology and discloses a multi-stage recovery and utilization system for steam condensate heat energy and water. It includes a condensate recovery tank, a drying tower, a first heat exchanger, a second heat exchanger, and a cooling tower. The heat source inlet of the first heat exchanger is connected to the condensate recovery tank, and the first heat exchanger is used to preheat the gas entering the drying tower. The heat source inlet of the second heat exchanger is connected to the heat source outlet of the first heat exchanger, the heat source outlet of the second heat exchanger is connected to the cooling tower, and the cold source inlet of the second heat exchanger is used to connect to an external water supply system. This multi-stage recovery and utilization system for steam condensate heat energy and water can fully utilize the heat energy and condensate water, reducing the cost of milk powder processing.

Description

Technical Field

[0001] This utility model relates to the field of milk powder processing technology, and in particular to a steam condensate heat energy and water multi-stage recovery and utilization system. Background Technology

[0002] Milk powder primarily refers to powder made from cow's milk through processes such as sterilization, defatting, dehydration, and drying. It can also refer to products made from the milk of other animals, such as goats. In milk powder production, liquid milk is first evaporated and dehydrated to form concentrated milk. This concentrated milk is then transported through pipes to a drying tower, where it is sprayed in a mist. The drying tower uses high-temperature air to heat and dry the concentrated milk, thus producing dry milk powder. This high-temperature air is created by heating room-temperature air with high-temperature steam. The high-temperature steam condenses into hot water exceeding 90 degrees Celsius. Furthermore, before evaporation, the liquid milk needs to be sterilized, which also requires high-temperature steam. This high-temperature steam, after sterilizing the liquid milk, also easily condenses into hot water exceeding 90 degrees Celsius.

[0003] In summary, high-temperature condensate is easily generated in multiple stages of milk powder processing. Current technology usually discharges it directly into the sewer, and the waste heat and water are not utilized, resulting in a waste of heat energy and water resources. Utility Model Content

[0004] The purpose of this invention is to provide a steam condensate heat energy and water multi-stage recovery and utilization system to solve the problem of heat energy and water waste in the milk powder processing process.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A multi-stage steam condensate heat energy and water recovery and utilization system includes a condensate recovery tank, a drying tower, a first heat exchanger, a second heat exchanger, and a cooling tower; the heat source inlet of the first heat exchanger is connected to the condensate recovery tank, and the first heat exchanger is used to preheat the gas introduced into the drying tower; the heat source inlet of the second heat exchanger is connected to the heat source outlet of the first heat exchanger, the heat source outlet of the second heat exchanger is connected to the cooling tower, and the cold source inlet of the second heat exchanger is used to connect to an external water supply system.

[0007] In one embodiment, the cooling tower includes a first cooling tower for cooling the evaporation equipment, a second cooling tower for cooling the air compressor, and a third cooling tower for cooling the refrigeration compressor, wherein the first cooling tower, the second cooling tower, and the third cooling tower are connected in series.

[0008] In one embodiment, the first heat exchanger is a coil heat exchanger, which is arranged around the side of the drying tower where the air inlet is located.

[0009] In one embodiment, the second heat exchanger is a plate heat exchanger.

[0010] In one embodiment, a transfer tank is provided between the first heat exchanger and the second heat exchanger, and the heat source outlet of the second heat exchanger is connected to the inlet of the transfer tank and the inlet of the cooling tower through a first three-way valve.

[0011] In one embodiment, a first temperature sensor is provided at the heat source outlet of the first heat exchanger, and the first temperature sensor is communicatively connected to the first three-way valve.

[0012] In one embodiment, a water supply tank is provided between the heat source outlet of the second heat exchanger and the cooling tower, and a first control valve is provided between the water supply tank and the cooling tower. The first control valve is used to control the on / off connection between the water supply tank and the cooling tower.

[0013] In one embodiment, the cooling tower is connected to the inlet of the water supply tank and the outlet of the water supply tank via a second three-way valve.

[0014] In one embodiment, the cold source outlet of the second heat exchanger is connected to the inlet of the cooling tower, and a second control valve is provided between the cold source outlet of the second heat exchanger and the cooling tower. The second control valve is used to control the on / off connection between the cold source outlet of the second heat exchanger and the cooling tower.

[0015] In one embodiment, a water storage tank is also provided between the condensate recovery tank and the drying tower, and the height of the water storage tank is higher than the height of the condensate recovery tank.

[0016] The beneficial effects of this invention are as follows: The above-mentioned steam condensate heat energy and water multi-stage recovery and utilization system exchanges heat between the high-temperature condensate in the condensate recovery tank and the gas introduced into the drying tower through the first heat exchanger. The heat of the high-temperature condensate is transferred to the gas, raising the inlet air temperature of the drying tower to 40℃-50℃, saving the high-temperature steam used by the subsequent steam heater to heat the gas. After exchanging heat with the gas, the condensate undergoes secondary heat exchange with the water in the external water supply system, reducing the temperature of the condensate by below 25℃. The condensate is then fed into the cooling tower, which is mainly used to cool down the various processing equipment in the milk powder processing system, such as power equipment or evaporation equipment. The cooled water after cooling the processing equipment returns to the cooling tower and mixes with the condensate. Compared with natural heat dissipation, this can lower the temperature of the cooled water in the cooling tower more quickly, thereby helping to accelerate the circulation and utilization of the cooled water in the cooling tower. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the steam condensate heat energy and water multi-stage recovery and utilization system of this utility model.

[0018] In the picture:

[0019] 1. Condensate recovery tank; 2. Drying tower; 3. Transfer tank; 4. Second heat exchanger; 5. Water supply tank; 6. Water storage tank; 7. First cooling tower; 8. Second cooling tower; 9. Third cooling tower; 10. Water hammer expander; 11. Water pump; 12. First three-way valve; 13. Second three-way valve; 14. Control valve. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0021] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0022] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0023] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0024] refer to Figure 1As shown in the figure, this utility model proposes a multi-stage steam condensate heat energy and water recovery and utilization system, including a condensate recovery tank 1, a first heat exchanger (not shown in the figure), a drying tower 2, a second heat exchanger 4, and a cooling tower. The condensate recovery tank 1 is used to collect high-temperature condensate generated during the milk powder processing process. The heat source inlet of the first heat exchanger is connected to the outlet of the condensate recovery tank 1. The first heat exchanger is used to preheat the gas introduced into the drying tower 2. The drying tower 2 is used to dry concentrated milk, and it heats the gas through a steam heater. To reduce drying costs, air is typically used. It should be emphasized that the steam in the steam heater also produces condensate after heating the gas; that is, the drying tower 2 is one of the sources of high-temperature condensate. The condensate outlet of the drying tower 2 is connected to the inlet of the condensate recovery tank 1. The drying tower 2 is prior art and will not be described in detail here. The heat source inlet of the second heat exchanger 4 is connected to the heat source outlet of the first heat exchanger, and the heat source outlet of the second heat exchanger 4 is connected to the cooling tower. Both the cold source inlet and cold source outlet of the second heat exchanger 4 are connected to an external water supply system. The water supplied by the external water supply system can be used to clean the various processing equipment in the milk powder processing system. The processing equipment in the milk powder processing system is not limited to evaporation equipment for evaporating liquid milk to turn liquid milk into concentrated milk and drying tower 2.

[0025] The aforementioned steam condensate heat energy and water multi-stage recovery and utilization system uses a first heat exchanger to exchange heat between the high-temperature condensate in the condensate recovery tank 1 and the gas introduced into the drying tower 2. The heat from the high-temperature condensate is transferred to the gas, raising the inlet air temperature of the drying tower 2 to 40℃-50℃, saving the high-temperature steam used by the subsequent steam heater to heat the gas. After heat exchange with the gas, the condensate undergoes a secondary heat exchange with water in the external water supply system, lowering its temperature by below 25℃. Since the water in the external water supply system can be used to clean the various processing equipment in the milk powder processing system, the increased water temperature helps remove dirt. The external water supply system can supply softened water or tap water; no specific restrictions are made here. The condensate is then fed into a cooling tower, which is mainly used to cool the various processing equipment in the milk powder processing system, such as power equipment or evaporation equipment. The cooled water, after cooling the processing equipment, returns to the cooling tower and mixes with the condensate. Compared to natural heat dissipation, this can lower the temperature of the cooling water in the cooling tower more quickly, thus helping to accelerate the circulation and utilization of the cooling water in the cooling tower.

[0026] Specifically, the cooling tower includes a first cooling tower 7 for cooling the evaporator, a second cooling tower 8 for cooling the air compressor, and a third cooling tower 9 for cooling the refrigeration compressor, connected in series. The second cooling tower 8 and the third cooling tower 9 are collectively referred to as the power cooling tower. Alternatively, only one cooling tower may be installed, simultaneously cooling the evaporator, air compressor, and refrigeration compressor.

[0027] In one embodiment, the first heat exchanger is a coil heat exchanger, which is arranged around the side of the drying tower 2 where the air inlet is provided to preheat the gas. The air inlet is used to introduce gas into the drying tower 2. It can be understood that using a coil heat exchanger eliminates the process of introducing gas into the first heat exchanger, thus avoiding gas energy loss.

[0028] The second heat exchanger 4 is a plate heat exchanger, in which condensate and water from the external water supply system are respectively introduced into the plate heat exchanger to achieve heat exchange.

[0029] To prevent the condensate from failing to meet the cooling tower's requirements after heat exchange in the second heat exchanger 4, a transfer tank 3 is installed between the first and second heat exchangers 4. The heat source outlet of the second heat exchanger 4 is connected to the inlet of the transfer tank 3 and the inlet of the cooling tower via a first three-way valve 12. When the condensate temperature is still higher than the required cooling tower temperature after heat exchange in the second heat exchanger 4, the first three-way valve 12 connects the heat source outlet of the second heat exchanger 4 to the transfer tank 3; conversely, when the condensate temperature is lower than the required cooling tower temperature after heat exchange in the second heat exchanger 4, the first three-way valve 12 connects the heat source outlet of the second heat exchanger 4 to the cooling tower.

[0030] Furthermore, the first three-way valve 12 is a solenoid valve. The steam condensate heat energy and water multi-stage recovery and utilization system also includes a first temperature sensor installed at the heat source outlet of the first heat exchanger. The first temperature sensor is communicatively connected to the first three-way valve 12 to achieve automatic adjustment of the first three-way valve 12. When the first temperature sensor detects that the fluid temperature is lower than a preset first threshold, the first three-way valve 12 connects the heat source outlet of the second heat exchanger 4 to the cooling tower; when the first temperature sensor detects that the fluid temperature is higher than the preset first threshold, the first three-way valve 12 connects the heat source outlet of the second heat exchanger 4 to the transfer tank 3, so that the condensate circulates between the transfer tank 3 and the second heat exchanger 4 until the temperature of the condensate is lower than the preset first threshold. For example, the first threshold is between 20-25°C, for example, the first threshold is 20°C, 23°C, or 25°C.

[0031] Understandably, when the outdoor temperature is too low, the milk powder processing system does not need to use cooling water for cooling, that is, the water in the cooling tower will not be consumed, and there is no need to replenish the cooling tower with cooling water. On this basis, the steam condensate heat energy and water multi-stage recovery and utilization system also includes a water supply tank 5. The water supply tank 5 is located between the heat source outlet of the second heat exchanger 4 and the cooling tower. A first control valve 14 is installed between the water supply tank 5 and the cooling tower. The first control valve 14 is used to control the on / off of the water supply tank 5 and the cooling tower. The condensate after heat exchange by the second heat exchanger 4 can be stored in the water supply tank 5.

[0032] Specifically, in order to prevent the pipes connecting the water supply tank 5 and the cooling tower from freezing and breaking when the temperature is too low, the cooling tower connects the inlet and outlet of the water supply tank 5 through the second three-way valve 13. By adjusting the second three-way valve 13, the cooling water circulates between the inlet and outlet of the water supply tank 5 and does not flow through the cooling tower.

[0033] Furthermore, the cold source outlet of the second heat exchanger 4 is connected to the inlet of the cooling tower, and a second control valve 14 is installed between the cold source outlet of the second heat exchanger 4 and the cooling tower. The second control valve 14 is used to control the on / off connection between the cold source outlet of the second heat exchanger 4 and the cooling tower. When the condensate water volume is insufficient to compensate for the cooling water consumption in the cooling tower, water can be replenished to the cooling tower through an external water supply system.

[0034] To make efficient use of space, existing milk powder processing systems typically have multiple layers stacked vertically. To ensure that the condensate carrying heat flows smoothly into the condensate recovery tank 1, the condensate recovery tank 1 is located on the first basement level. However, due to the limited space on the first basement level, a water storage tank 6 is also installed between the condensate recovery tank 1 and the drying tower 2. The height of the water storage tank 6 is higher than that of the condensate recovery tank 1.

[0035] In addition, a water hammer expander 10 is installed between the condensate recovery tank 1 and the external water supply system, that is, a water hammer expander 10 is installed at the inlet of the condensate recovery tank to eliminate water hammer. The water hammer expander 10 is prior art and will not be described in detail here.

[0036] Understandably, in order to provide the flow power for condensate, the steam condensate heat energy and water multi-stage recovery and utilization system also includes a water pump 11. For example, water pumps 11 are installed between the condensate recovery tank 1 and the water storage tank 6, between the water storage tank 6 and the drying tower 2, between the transfer tank 3 and the second heat exchanger 4, and between the water supply tank 5 and the cooling tower.

[0037] Taking the production of 14,000 kg of condensate per hour during milk powder processing as an example, assuming that the above-mentioned steam condensate heat energy and water multi-stage recovery and utilization system runs together with the milk powder processing system for 330 days a year, 18 hours a day, as shown in Table 1, it can save 4,836 tons of steam per year, and each ton of steam costs about 207 yuan, so it can save 1,001,100 yuan per year.

[0038] Table 1

[0039]

[0040] As shown in Table 2, before and after using the steam condensate heat energy and water multi-stage recovery and utilization system, the annual water consumption of the evaporator cooling tower and the power cooling tower is reduced by 15,180 tons and 3,300 tons respectively, saving 272,200 yuan / year (calculated based on tap water price).

[0041] Table 2

[0042]

[0043] In summary, a total of 1.2733 million yuan can be saved annually.

[0044] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A multi-stage recovery and utilization system for steam condensate heat energy and water, characterized in that, include: Condensate recovery tank (1); Drying tower (2); The first heat exchanger has its heat source inlet connected to the condensate recovery tank (1) and is used to preheat the gas introduced into the drying tower (2). The second heat exchanger (4) has its heat source inlet connected to the heat source outlet of the first heat exchanger, its heat source outlet connected to the cooling tower, and its cold source inlet connected to an external water supply system.

2. The steam condensate heat energy and water multi-stage recovery and utilization system according to claim 1, characterized in that, The cooling tower includes a first cooling tower (7) for cooling the evaporation equipment, a second cooling tower (8) for cooling the air compressor, and a third cooling tower (9) for cooling the refrigeration compressor, wherein the first cooling tower (7), the second cooling tower (8), and the third cooling tower (9) are connected in series.

3. The steam condensate heat energy and water multi-stage recovery and utilization system according to claim 1, characterized in that, The first heat exchanger is a coil heat exchanger, which is arranged around the side of the drying tower (2) where the air inlet is located.

4. The steam condensate heat energy and water multi-stage recovery and utilization system according to claim 1, characterized in that, The second heat exchanger (4) is a plate heat exchanger.

5. The steam condensate heat energy and water multi-stage recovery and utilization system according to claim 1, characterized in that, A transfer tank (3) is provided between the first heat exchanger and the second heat exchanger (4). The heat source outlet of the second heat exchanger (4) is connected to the inlet of the transfer tank (3) and the inlet of the cooling tower through a first three-way valve (12).

6. The steam condensate heat energy and water multi-stage recovery and utilization system according to claim 5, characterized in that, The heat source outlet of the first heat exchanger is equipped with a first temperature sensor, which is communicatively connected to the first three-way valve (12).

7. The steam condensate heat energy and water multi-stage recovery and utilization system according to claim 1, characterized in that, A water supply tank (5) is provided between the heat source outlet of the second heat exchanger (4) and the cooling tower. A first control valve (14) is provided between the water supply tank (5) and the cooling tower. The first control valve (14) is used to control the on / off state of the water supply tank (5) and the cooling tower.

8. The steam condensate heat energy and water multi-stage recovery and utilization system according to claim 7, characterized in that, The cooling tower is connected to the inlet of the water supply tank (5) and the outlet of the water supply tank (5) via a second three-way valve (13).

9. The steam condensate heat energy and water multi-stage recovery and utilization system according to claim 1, characterized in that, The cold source outlet of the second heat exchanger (4) is connected to the inlet of the cooling tower, and a second control valve (14) is provided between the cold source outlet of the second heat exchanger (4) and the cooling tower. The second control valve (14) is used to control the on / off connection between the cold source outlet of the second heat exchanger (4) and the cooling tower.

10. The steam condensate heat energy and water multi-stage recovery and utilization system according to claim 1, characterized in that, A water storage tank (6) is also provided between the condensate recovery tank (1) and the drying tower (2), and the height of the water storage tank (6) is higher than the height of the condensate recovery tank (1).

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