A foaming waste heat recovery system

Abstract

The utility model discloses a kind of foaming waste heat recovery systems, comprising: reaction kettle, jacket is equipped on reaction kettle, steam inlet and steam outlet are equipped on jacket;Reaction kettle is also equipped with water inlet and pressure relief pipeline communicated with its inside, and pressure relief pipeline is communicated with the feed inlet of solid-liquid separation device;Recovery pool, recovery pool is used to contain heat exchange working medium, and recovery pool is communicated with steam outlet and the drain port of solid-liquid separation device;Heat exchanger, setting in recovery pool and immerging in heat exchange working medium, heat exchanger has water inlet and water outlet, water inlet is communicated with cold water source by valve and delivery pump, and water outlet is communicated with the water inlet pipe of flushing device or / and the water inlet of reaction kettle. Heat exchanger is heated to cold water as needed and is delivered to reaction kettle as reaction water or flushing device as cleaning water, realize the centralized recovery and reuse of waste heat;Recovery pool is used as heat buffer unit, and working medium temperature is stabilized, and the temperature fluctuation of output water is small, and process stability is improved.

Description

Technical Field

[0001] This application relates to the technical field of waste heat recovery systems for foaming processes. Background Technology

[0002] In the production process of polypropylene foamed materials, the reactor is the core equipment. Its jacket typically circulates high-temperature saturated steam to heat and foam the raw materials inside. Simultaneously, reaction water is injected into the reactor as a heat transfer medium and dispersant. If the hot water discharged from the reactor and the steam discharged from the jacket are directly released after foaming, it will result in a significant waste of heat and water resources, which is inconsistent with the industry trend of energy conservation and emission reduction. Utility Model Content

[0003] This utility model aims to solve at least one of the technical problems existing in the prior art. To this end, this utility model proposes: A foaming waste heat recovery system, comprising: The reactor is equipped with a jacket, which has a steam inlet and a steam outlet. The reactor also has a water inlet and a pressure relief pipe communicating with its interior. The pressure relief pipe is connected to the feed inlet of a solid-liquid separation device. A recovery tank is used to hold the heat exchange working fluid, and the recovery tank is connected to the steam outlet and the drain outlet of the solid-liquid separation device; A heat exchanger is disposed in the recovery tank and immersed in the heat exchange working fluid. The heat exchanger includes a cold channel and an inlet and an outlet connected to the cold channel. The inlet is connected to a cold water source through a valve and a delivery pump. The outlet is connected to the inlet pipe of the flushing device and / or the water inlet of the reactor.

[0004] The technical solution adopted by one embodiment of this utility model to solve its technical problem is as follows: the heat exchanger includes a first heat exchanger, the first heat exchanger has a heat channel and a heat exchange inlet and a heat exchange outlet communicating with the heat channel, the water inlet of the first heat exchanger is connected to the water outlet of the delivery pump through a first valve, the water inlet of the delivery pump is connected to the cold water source, the steam outlet is connected to the heat exchange inlet, and a one-way valve is provided at the heat exchange outlet.

[0005] The technical solution adopted by one embodiment of this utility model to solve its technical problem is as follows: the heat exchange inlet is connected to one interface of the three-way valve, the other interface of the three-way valve is connected to the steam outlet, the remaining interface of the three-way valve is connected to one end of the steam pipeline, and the other end of the steam pipeline is connected to the recovery tank. The three-way valve can selectively connect the steam outlet to the heat exchange inlet, or connect the steam outlet to the steam pipeline.

[0006] The technical solution adopted by one embodiment of this utility model to solve its technical problem is: the end of the steam pipe that extends into the recycling tank is provided with a porous structure, the porous structure including a plurality of small holes communicating with the interior of the steam pipe.

[0007] The technical solution adopted by one embodiment of this utility model to solve its technical problem is: the first heat exchanger is a shell-and-tube heat exchanger.

[0008] The technical solution adopted by one embodiment of this utility model to solve its technical problem is as follows: the heat exchanger further includes a second heat exchanger, the inlet of the second heat exchanger is connected to the outlet of the delivery pump through a second valve, and the outlet of the second heat exchanger is connected to the inlet pipe of the flushing device.

[0009] The technical solution adopted by one embodiment of this utility model to solve its technical problem is: the second heat exchanger is a coil heat exchanger.

[0010] The technical solution adopted by one embodiment of this utility model to solve its technical problem is: the solid-liquid separation device is a hydrocyclone.

[0011] The beneficial effects of this utility model are as follows: the steam discharged from the jacket of the reactor and the hot water discharged from the reactor are collected by the recovery tank. The heat exchanger in the heat exchange medium immersed in the recovery tank heats the cold water and delivers it to the reactor as reaction water or to the rinsing device as cleaning water as needed, so as to realize the centralized recovery and reuse of waste heat. The recovery tank acts as a heat buffer unit to stabilize the temperature of the working medium, and the temperature fluctuation of the output water is small, which improves the stability of the process. Attached Figure Description

[0012] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the foaming waste heat recovery system described in this embodiment. Detailed Implementation

[0013] This section will describe in detail the specific embodiments of the present utility model. The preferred embodiments of the present utility model are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present utility model, but they should not be construed as limiting the scope of protection of the present utility model.

[0014] In the description of this utility model, "multiple" means two or more; "greater than," "less than," and "exceeding" are understood to exclude the stated number; "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly specifying the number of indicated technical features or their sequential relationship.

[0015] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, 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.

[0016] In this utility model, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to a fixed connection, a detachable connection, or an integral molding; they can refer to a mechanical connection; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0017] Reference Figure 1 This application proposes an embodiment of the foaming waste heat recovery system, which includes: The reactor 10 is equipped with a jacket 20, which has a steam inlet 21 and a steam outlet 22. The reactor 10 also has a water inlet 11 and a pressure relief pipe 12 communicating with its interior. The pressure relief pipe 12 is connected to the feed inlet 31 of the solid-liquid separation device 30. Recovery tank 40, which is used to hold heat exchange working fluid, is connected to steam outlet 22 and drain outlet 42 of solid-liquid separation device 30; A heat exchanger 50 is disposed in the recovery tank 40 and immersed in the heat exchange working medium. The heat exchanger 50 includes a cold channel and an inlet 51 and an outlet 52 connected to the cold channel. The inlet 51 is connected to a water source through a valve 60 and a transfer pump 70. The outlet 52 is connected to the inlet pipe of the flushing device 80 and / or the water inlet 11 of the reaction vessel 10.

[0018] The working principle of the foaming waste heat recovery system described in this embodiment is as follows: saturated steam is introduced into the jacket 20 of the reactor 10 through the steam inlet 21 to heat the raw materials in the reactor. The steam after heat exchange is discharged from the steam outlet 22 and flows into the recovery tank 40. The hot water in the reactor 10 enters the solid-liquid separation device 30 through the pressure relief pipe 12. The separated water flows into the recovery tank 40 from the drain outlet 42.

[0019] The recovery tank 40 contains a heat exchange working fluid, such as water. The recovery tank 40 receives steam discharged from the jacket 20 and hot water after solid-liquid separation to form a high-temperature working fluid pool. The heat exchanger 50 is immersed in the working fluid in the recovery tank 40. Its inlet is connected to an external cold water source. The first valve 60a is opened, and the transfer pump 70 is started. The cold water is sent into the heat exchanger 50 and absorbs heat from the working fluid to raise its temperature. Then, the hot water is pumped through the outlet 52 to the reaction vessel 10 as reaction water or to the rinsing device 80 as cleaning water.

[0020] Steam discharged from the jacket 20 of the reactor 10 and hot water discharged from the reactor 10 are collected in the recovery tank 40. The heat exchanger 50, which is immersed in the heat exchange medium in the recovery tank 40, heats the cold water and delivers it to the reactor 10 as reaction water or to the rinsing device 80 as cleaning water as needed, so as to achieve centralized recovery and reuse of waste heat. The recovery tank 40 serves as a heat buffer unit to stabilize the temperature of the working medium, ensure that the temperature fluctuation of the output water is small, and improve the stability of the process.

[0021] The cold water source is a cold water tank, and the water is stored in the cold water tank to ensure a stable water supply flow to the heat exchanger.

[0022] The recycling tank is equipped with a water level gauge. When the water level in the recycling tank exceeds a preset value, a preset volume of working fluid is extracted from the recycling tank to ensure that the water level in the recycling tank remains stable.

[0023] In another embodiment, a thermometer and an instant heater can also be installed at the outlet 52 to ensure that the water supply temperature of the heat exchanger 50 to the reaction water or cleaning water of the reactor is stable.

[0024] Specifically, the heat exchanger 50 includes a first heat exchanger 50a, which has a heat channel and a heat exchange inlet 53 and a heat exchange outlet 54 connected to the heat channel. The inlet 51 of the first heat exchanger 50a is connected to the outlet of the delivery pump 70 through a first valve 60a. The inlet of the delivery pump 70 is connected to the cold water source. The steam outlet 22 is connected to the heat exchange inlet 53. A one-way valve 110 is provided at the heat exchange outlet 54.

[0025] The heat exchange inlet 53 of the first heat exchanger 50a is connected to the steam outlet 22 of the jacket 20 via a pipe. Opening the first valve 60a and starting the transfer pump 70 allows cold water to flow into the cold passage of the first heat exchanger 50a, while steam enters the hot passage of the first heat exchanger 50a, exchanging heat with the cold water flowing inside the heat exchanger 50. Condensate or residual steam is discharged from the heat exchange outlet 54 into the recovery tank 40. A one-way valve 110 ensures that the steam / condensate flows only towards the recovery tank 40, preventing the working fluid in the recovery tank 40 from flowing back into the first heat exchanger 50a.

[0026] The first heat exchanger 50a is set as a dedicated heat exchanger for steam. It receives steam from the jacket 20 through its heat exchange inlet 53. The steam directly exchanges heat with the cold water in the first heat exchanger 50a. After releasing heat in the heat exchanger 50, the steam is discharged from the heat exchange outlet 54, realizing the directional and efficient utilization of steam waste heat to meet the temperature requirements of the reaction water.

[0027] When saturated steam with a saturated steam pressure of 2 MPa enters the jacket 20 and exchanges heat with the raw materials in the reactor 10, the steam releases latent heat and condenses into a steam-water mixture. This steam-water mixture is introduced into the shell side of the first heat exchanger 50a through the three-way valve 90, where it exchanges heat with the water to be heated in the tube side. After further releasing sensible heat, it is discharged from the heat exchange outlet 54 of the first heat exchanger 50a, where the temperature drops to 120-150°C, and finally flows into the recovery tank 40.

[0028] If the system operates without reaction water, the steam-water mixture discharged from jacket 20 enters recovery tank 40 directly through steam pipe 100, mixing with the existing heat exchange medium in the tank, such as circulating water at 60-90℃, raising the temperature of the medium in recovery tank 40 to 90-130℃. At this time, the second heat exchanger 50b is immersed in this high-temperature medium. The cleaning water flowing in its tubes at a normal temperature of 20-30℃ absorbs heat, and its temperature when flowing out of the second heat exchanger 50b can be stabilized at 30-60℃. This temperature can meet the requirements for removing surface impurities during bead cleaning, while avoiding secondary expansion or deformation of the foamed beads due to excessively high temperatures.

[0029] Preferably, the heat exchange inlet 53 is connected to one port of the three-way valve 90, the other port of the three-way valve 90 is connected to the steam outlet 22, the remaining port of the three-way valve 90 is connected to one end of the steam pipe 100, and the other end of the steam pipe 100 is connected to the recovery tank 40. The three-way valve 90 can selectively connect the steam outlet 22 to the heat exchange inlet 53, or connect the steam outlet 22 to the steam pipe 100.

[0030] When the reactor 10 requires reaction water, the first valve 60a is opened and the first transfer pump 70a is started. The first transfer pump 70a transports cold water from the cold water source to the cold channel. At this time, the three-way valve 90 connects the steam outlet 22 and the heat exchange inlet 53, and the steam enters the first heat exchanger 50a, prioritizing the high-temperature requirement of the reaction water. When reaction water is not needed, the first valve 60a is closed and the first transfer pump 70a is closed. The three-way valve 90 connects the steam outlet 22 and the steam pipeline 100, and the steam directly enters the recovery tank 40 to heat the working medium, providing a heat source for the cleaning water, thus achieving on-demand heat distribution and high-temperature priority protection.

[0031] Preferably, one end of the steam pipe 100 that extends into the recycling tank 40 is provided with a porous structure 101, the porous structure 101 including a plurality of small holes communicating with the interior of the steam pipe 100.

[0032] The porous structure 101 disperses the steam into fine bubbles and introduces it into the heat exchange working medium in the recovery tank 40. The porous structure 101 at the end of the steam pipe 100 disperses the steam into fine bubbles, increases the contact area between the steam and the working medium in the recovery tank 40, improves the steam condensation and heat release efficiency, and ensures that the steam heat can be fully transferred to the working medium in the recovery tank 40 when no reaction water is needed.

[0033] In this embodiment, the first heat exchanger 50a is a shell-and-tube heat exchanger.

[0034] The shell side of the shell-and-tube heat exchanger is a hot passage for steam flow, and the tube side is a cold passage for water to be heated. The two ends of the shell side correspond to the heat exchange inlet 53 and heat exchange outlet 54 of the first heat exchanger 50a, respectively, and the two ends of the tube side correspond to the water inlet 51 and water outlet 52 of the first heat exchanger 50a, respectively. The inner wall of the shell side is provided with a baffle plate to extend the flow path of steam in the shell side.

[0035] The shell-and-tube structure has high heat exchange stability. The outlet temperature of the reaction water can be controlled by adjusting the steam flow rate into the shell-and-tube heat exchanger, thus avoiding uneven foaming of the beads caused by temperature fluctuations.

[0036] In this embodiment, the heat exchanger 50 further includes a second heat exchanger 50b. The inlet 51 of the second heat exchanger 50b is connected to the outlet of the delivery pump 70 through a second valve 60b. The inlet of the delivery pump 70 is connected to the cold water source. The outlet 52 of the second heat exchanger 50b is connected to the inlet pipe of the flushing device 80.

[0037] The second heat exchanger 50b is immersed in the working fluid of the recovery tank 40, and its outlet 52 is connected to the rinsing device 80. When rinsing of the foamed beads is required, the second valve 60b and the second transfer pump 70b are activated, and cold water flows into the second heat exchanger 50b. The working fluid in the recovery tank 40 exchanges heat with the cold water in the second heat exchanger 50b, heating it to 30-60°C before it is conveyed to the rinsing device 80. The rinsing device 80 is prior art and will not be described in detail in this application.

[0038] In this application, the second heat exchanger 50b is a coil heat exchanger. The coils of the coil heat exchanger are arranged in an S-shape, and rectangular fins are welded to the outer wall of the coils to ensure heat exchange efficiency.

[0039] Both the water inlet 11 of the reactor 10 and the water inlet pipe of the rinsing device 80 are equipped with flow valves. The flow valves are electrically connected to the control system of the reactor 10. The delivery pump 70 is a variable frequency water pump. When the reactor 10 is replenished with water through the water inlet 11 or / and water is delivered to the rinsing device 80, the control system adjusts the delivery flow rate of the delivery pump 70 according to the set liquid level in the reactor 10 or the rated water consumption of the rinsing device 80 and the flow rate of the flow valve.

[0040] In this embodiment, the solid-liquid separation device 30 is a hydrocyclone.

[0041] Of course, this utility model is not limited to the above-described embodiments. Those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of this utility model. All such equivalent modifications and substitutions are included within the scope defined by the claims of this application.

Claims

1. A foaming waste heat recovery system, characterized in that, include: The reactor (10) is equipped with a jacket (20), which has a steam inlet (21) and a steam outlet (22). The reactor (10) is also equipped with a water inlet (11) and a pressure relief pipe (12) connected to its interior. The pressure relief pipe (12) is connected to the feed inlet (31) of the solid-liquid separation device (30). A recovery tank (40) is used to hold a heat exchange working fluid, and the recovery tank (40) is connected to the steam outlet (22) and the drain outlet (42) of the solid-liquid separation device (30); A heat exchanger (50) is disposed in the recovery tank (40) and immersed in the heat exchange working medium. The heat exchanger (50) includes a cold channel and an inlet (51) and an outlet (52) connected to the cold channel. The inlet (51) is connected to a cold water source through a valve (60) and a transfer pump (70). The outlet (52) is connected to the inlet pipe of the flushing device (80) and / or the water inlet (11) of the reactor (10).

2. The foaming waste heat recovery system according to claim 1, characterized in that, The heat exchanger (50) includes a first heat exchanger (50a), which has a heat channel and a heat exchange inlet (53) and a heat exchange outlet (54) connected to the heat channel. The inlet (51) of the first heat exchanger (50a) is connected to the outlet of the delivery pump (70) through a first valve (60a). The inlet of the delivery pump (70) is connected to the cold water source. The steam outlet (22) is connected to the heat exchange inlet (53). A one-way valve (110) is provided at the heat exchange outlet (54).

3. The foaming waste heat recovery system according to claim 2, characterized in that, The heat exchange inlet (53) is connected to one port of the three-way valve (90), the other port of the three-way valve (90) is connected to the steam outlet (22), the remaining port of the three-way valve (90) is connected to one end of the steam pipe (100), the other end of the steam pipe (100) is connected to the recovery tank (40), and the three-way valve (90) can selectively connect the steam outlet (22) to the heat exchange inlet (53), or connect the steam outlet (22) to the steam pipe (100).

4. The foaming waste heat recovery system according to claim 3, characterized in that, The end of the steam pipe (100) that extends into the recycling tank (40) is provided with a porous structure (101), the porous structure (101) including a plurality of small holes communicating with the interior of the steam pipe (100).

5. The foaming waste heat recovery system according to claim 3, characterized in that, The first heat exchanger (50a) is a shell-and-tube heat exchanger.

6. The foaming waste heat recovery system according to any one of claims 2-5, characterized in that, The heat exchanger (50) further includes a second heat exchanger (50b), the inlet (51) of which is connected to the outlet of the delivery pump (70) via a second valve (60b), and the outlet (52) of which is connected to the inlet pipe of the flushing device (80).

7. The foaming waste heat recovery system according to claim 6, characterized in that, The second heat exchanger (50b) is a coil heat exchanger.

8. The foaming waste heat recovery system according to claim 1, characterized in that, The solid-liquid separation device (30) is a hydrocyclone.

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