Cooler secondary refrigerant ethylene glycol recycling device for fine chemical engineering

Abstract

The invention discloses a cooler secondary refrigerant ethylene glycol recycling device for fine chemical engineering, comprising: a collection tank, the top of which is provided with a blow-down pipe, the air inlet of which is connected with an exhaust pipe of a cooler; the liquid level meter is arranged in the collecting tank; a pump inlet pipe of the recovery pump is connected with a liquid outlet in the bottom of the collection tank, and a pump outlet pipe is communicated with an ethylene glycol outlet pipe of the cooler; the signal input end of the PLC is connected with the signal output end of the liquid level meter, and the start-stop control part of the PLC is connected with the start-stop control end of the recovery pump. Through reasonable system design and technical means, the loss of ethylene glycol can be reduced to the greatest extent on the premise of not influencing normal production and equipment maintenance.

Description

Technical Field

[0001] This invention relates to the technical field of ethylene glycol recovery equipment for coolers, and particularly to a device for recovering and utilizing ethylene glycol, a coolant used in fine chemical industries. Background Technology

[0002] In the fine chemical industry, ethylene glycol is widely used as a refrigerant in cooling systems. Ethylene glycol aqueous solutions are highly favored due to their unique physicochemical properties. They can remain liquid at low temperatures without freezing, making them suitable for a wide temperature range. They also possess good thermal stability and oxidation resistance, allowing for long-term use at higher temperatures without decomposition. Furthermore, they exhibit high heat transfer efficiency, with their high specific heat capacity and thermal conductivity enabling them to effectively absorb and release heat, thus improving heat exchange efficiency. At the same time, even at low temperatures, ethylene glycol aqueous solutions maintain a low viscosity, which is beneficial for pumping and circulation, reducing system energy consumption.

[0003] However, the use of ethylene glycol in practical applications is not without challenges. Especially during heat exchanger operation, venting operations cause some ethylene glycol to be released with the gas, resulting in unnecessary waste. Furthermore, when equipment requires maintenance, ethylene glycol is typically released from the system to ensure safety and maintenance effectiveness, which not only increases production costs but also puts pressure on the environment. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a device for recovering and utilizing ethylene glycol, a refrigerant in coolers used in fine chemical industries.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A device for recovering and utilizing ethylene glycol, a coolant in a fine chemical cooler, comprises: The collection tank is equipped with a vent pipe on top, and its air inlet is connected to the exhaust pipe of the cooler. The level gauge is installed inside the collection tank; The recovery pump has its inlet pipe connected to the drain port at the bottom of the collection tank, and its outlet pipe connected to the ethylene glycol outlet pipe of the cooler. The PLC controller's signal input terminal is connected to the signal output terminal of the level gauge, and its start / stop control section is connected to the start / stop control terminal of the recovery pump.

[0006] A check valve is installed on the outlet pipe of the recovery pump.

[0007] A first regulating valve is installed on the ethylene glycol inlet pipe of the cooler; a temperature sensor is installed on the material outlet of the cooler; a second regulating valve is installed on the exhaust pipe of the cooler; the signal output terminal of the temperature sensor is connected to the signal input terminal of the PLC controller; the start / stop control terminal of the first regulating valve is connected to the start / stop control section of the PLC controller; and the start / stop control terminal of the second regulating valve is connected to the start / stop control section of the PLC controller.

[0008] The cooler is equipped with a manual valve on its drain pipe, and the drain pipe is connected to the air inlet of the collection tank.

[0009] The beneficial effects of this invention are as follows: By setting up a collection tank, the air discharged from the cooler is collected uniformly. During operation, after running for 10 minutes with the first regulating valve open at more than 50%, if the temperature sensor detects no temperature drop, it indicates that air is not being discharged from the cooler. At this time, the second regulating valve is opened via the PLC controller to discharge air from the cooler. When the temperature begins to drop, it indicates that the air in the cooler's inner shell has been completely discharged, and the system automatically closes the second regulating valve. When the level gauge detects that the liquid level in the collection tank is >60%, the PLC controller interlocks the recovery pump, sending the ethylene glycol collected during venting back to the system for circulation, thus realizing the recycling and reuse of ethylene glycol. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the present invention; Among them, 1-cooler, 2-recovery pump, 3-collection tank, 4-PLC controller, 5-first regulating valve, 6-second regulating valve, 7-temperature sensor, 8-manual valve, 9-level gauge, 10-check valve, W1-material inlet, W2-material outlet, Y1-ethylene glycol inlet pipe, Y2-ethylene glycol outlet pipe, P1-exhaust pipe, P2-drain pipe, S1-pump inlet pipe, S2-pump outlet pipe, K-vent pipe. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the invention.

[0012] like Figure 1As shown, an apparatus for recovering and utilizing ethylene glycol, a coolant in a fine chemical cooler, includes: a collection tank 3 with a vent pipe at the top, the inlet of which is connected to the exhaust pipe of a cooler 1; a level gauge 9 installed inside the collection tank 3; a recovery pump 2, the pump inlet pipe of which is connected to the drain port at the bottom of the collection tank 3, and the pump outlet pipe of which is connected to the ethylene glycol outlet pipe of the cooler 1; and a PLC controller 4, the signal input terminal of which is connected to the signal output terminal of the level gauge 9, and the start / stop control section of which is connected to the start / stop control section of the recovery pump 2. A check valve 10 is installed on the pump outlet pipe of the recovery pump 2. A first regulating valve 5 is installed on the ethylene glycol inlet pipe of the cooler 1; a temperature sensor 7 is installed on the material outlet of the cooler 1; a second regulating valve 6 is installed on the exhaust pipe of the cooler 1; the signal output terminal of the temperature sensor 7 is connected to the signal input terminal of the PLC controller 4; the start / stop control section of the first regulating valve 5 is connected to the start / stop control section of the PLC controller 4; and the start / stop control section of the second regulating valve 6 is connected to the start / stop control section of the PLC controller 4. The cooler 1 is equipped with a manual valve 8 on its drain pipe, and the drain pipe is connected to the air inlet of the collection tank 3.

[0013] When using this invention, the first regulating valve 5 is activated to open to a degree greater than 50%. After running for 10 minutes, the temperature sensor 7 detects that the temperature display does not drop, indicating that there is air in the cooler 1 that has not been discharged. The second regulating valve 6 is opened by the PLC controller 4 to discharge the air from the cooler. When the temperature sensor 7 detects that the temperature begins to drop, it indicates that the air in the inner shell of the cooler has been discharged cleanly. The system automatically closes the second regulating valve 6. When the level gauge 9 detects that the liquid level in the collection tank 3 is greater than 60%, the PLC controller 4 starts the recovery pump (2) to send the ethylene glycol collected during the discharge back to the system for circulation.

[0014] Before the cooler 1 is dismantled and repaired, a drain pipe P2 can be connected after the shell-side valve of the cooler to recover all the ethylene glycol in the cooler 1 to the collection tank 3 for reuse.

[0015] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A device for recovering and utilizing ethylene glycol, a refrigerant in a fine chemical cooler, characterized in that, include: The collection tank (3) is equipped with a vent pipe on the top, and its air inlet is connected to the exhaust pipe of the cooler (1); A level gauge (9) is installed inside the collection tank (3); The recovery pump (2) has its inlet pipe connected to the bottom drain port of the collection tank (3) and its outlet pipe connected to the ethylene glycol outlet pipe of the cooler (1). The PLC controller (4) has its signal input terminal connected to the signal output terminal of the level gauge (9), and its start / stop control section is connected to the start / stop control terminal of the recovery pump (2).

2. The apparatus for recovering and utilizing ethylene glycol, a coolant in a fine chemical cooler, according to claim 1, is characterized in that, A check valve (10) is installed on the pump outlet pipe of the recovery pump (2).

3. The apparatus for recovering and utilizing ethylene glycol, a coolant in a fine chemical cooler, according to claim 1, is characterized in that... A first regulating valve (5) is installed on the ethylene glycol inlet pipe of the cooler (1); a temperature sensor (7) is installed on the material outlet of the cooler (1); a second regulating valve (6) is installed on the exhaust pipe of the cooler (1); the signal output terminal of the temperature sensor (7) is connected to the signal input terminal of the PLC controller (4); the start / stop control terminal of the first regulating valve (5) is connected to the start / stop control part of the PLC controller (4); the start / stop control terminal of the second regulating valve (6) is connected to the start / stop control part of the PLC controller (4).

4. The apparatus for recovering and utilizing ethylene glycol, a refrigerant in a fine chemical cooler, according to claim 1, is characterized in that... The cooler (1) is equipped with a manual valve (8) on its drain pipe, and the drain pipe is connected to the air inlet of the collection tank (3).

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