Tetrahydrofuran unloading and recycling system

Abstract

A tetrahydrofuran unloading and recycling system comprises a spherical tank (7) and a single-screw compressor (1), and is characterized in that a liquid return port of a tank truck (8) is communicated with a liquid inlet of the spherical tank (7), an exhaust port of the tank truck (8) is communicated with an air inlet of the single-screw compressor (1), and a liquid supplementing port of the single-screw compressor (1) is communicated with a liquid return port of the spherical tank (7); a liquid outlet of the single-screw compressor (1) is communicated with a liquid inlet of the gas-liquid separator (2), a liquid outlet of the gas-liquid separator (2) is communicated with the other liquid inlet of the spherical tank (7), and an exhaust port of the gas-liquid separator (2) is communicated with a gas inlet of the precooler (3). And an exhaust port of the precooler (3) is communicated with an exhaust pipe of the tank truck (8), so that redundant tetrahydrofuran is input back into the tank truck. According to the utility model, extra gas emission and loss cannot be caused, and the energy-saving and environment-friendly effects are good.

Description

Technical Field

[0001] The utility model relates to an organic volatile gas recovery technology, in particular to a tetrahydrofuran recovery technology, specifically a tetrahydrofuran unloading and recovery system. Background Art

[0002] As we all know, tetrahydrofuran (THF) is widely used in the pharmaceutical, chemical, textile, pesticide, and papermaking industries. It is also used in the automotive and daily chemical industries, serving as an important raw material for organic synthesis and a high-performance solvent. During the unloading process of tank trucks and spherical tanks, THF volatiles are generated and discharged directly into the atmosphere through breathing ports, resulting in the loss of THF solvent and environmental pollution. Utility Model Content

[0003] The utility model aims to design a tetrahydrofuran unloading and recovery system which can efficiently recover tetrahydrofuran in order to solve the problem that tetrahydrofuran gas filled in tank trucks and spherical tanks may cause air pollution due to volatilization during the unloading process.

[0004] The technical solution of the utility model is:

[0005] A tetrahydrofuran unloading and recovery system comprises a spherical tank 7 and a single-screw compressor 1, characterized in that: a liquid return port of a tank truck 8 is connected to the liquid inlet of the spherical tank 7, the exhaust port of the tank truck 8 is connected to the air inlet of the single-screw compressor 1, and the liquid replenishing port of the single-screw compressor 1 is connected to the liquid return port of the spherical tank 7; the liquid outlet of the single-screw compressor 1 is connected to the liquid inlet of a gas-liquid separator 2, the liquid discharge port of the gas-liquid separator 2 is connected to another liquid inlet of the spherical tank 7, the exhaust port of the gas-liquid separator 2 is connected to the air inlet of a precooler 3, the exhaust port of the precooler 3 is connected to the exhaust pipe of the tank truck 8 so that excess tetrahydrofuran can be recycled into the tank truck, the discharge port of the precooler 3 is connected to the liquid inlet of a condenser 4, the liquid outlet of the condenser 4 is connected to the liquid inlet of a liquid storage tank 6, and the liquid outlet of the liquid storage tank 6 is connected to the third liquid inlet of the spherical tank 7.

[0006] An aftercooler 5 is installed between the single-screw compressor 1 and the gas-liquid separator 2 .

[0007] The gas-liquid separator 2 is also connected to a compressed air source through a pipeline.

[0008] A first shut-off valve 9 , a first pressure sensor 11 , a first flow meter 12 , a first air intake filter 13 , a second pressure sensor 14 and a first one-way valve 15 are installed on the pipeline connecting the tank truck and the single-screw compressor 1 .

[0009] A second one-way valve 16 , a second on-off valve 17 , a first temperature sensor 18 , and a third pressure sensor 19 are installed on the pipeline connecting the single-screw compressor 1 and the gas-liquid separator 2 .

[0010] The gas-liquid separator 2 is equipped with a first liquid level sensor 20 and a safety valve 21 .

[0011] A second filter 32 and a third on-off valve 31 are installed on the pipeline connecting the gas-liquid separator 2 and the aftercooler 5 .

[0012] A third filter 28, a third one-way valve 29 and an eighth shut-off valve 35 are installed on the pipeline connecting the liquid outlet of the spherical tank 7 and the liquid inlet of the single-screw compressor 1; a short-circuit pipeline is provided between the pipeline connecting the liquid outlet of the spherical tank 7 and the liquid inlet of the single-screw compressor 1 and the pipeline connecting the aftercooler 5 and the gas-liquid separator 2, and a fourth shut-off valve 36 is installed on the short-circuit pipeline.

[0013] A second liquid level sensor 26 is installed on the liquid storage tank 6; a fifth on-off valve 27 is installed on the pipeline connecting the liquid outlet of the liquid storage tank 6 and the spherical tank 7, and a sixth on-off valve 30 is installed on the liquid outlet pipeline connecting the gas-liquid separator 2; a fourth one-way valve 22 and a first regulating valve 24 are installed on the pipeline connecting the air outlet of the precooler 3 and the tank truck 8; a seventh on-off valve 10 is installed on the pipeline connecting the spherical tank 7 and the air inlet pipe of the single-screw compressor 1; a second regulating valve 23 is installed on the pipeline connecting the precooler 3 with the spherical tank 7; a ninth on-off valve 34 and a fifth one-way valve 33 are installed on the compressed air supply pipe of the gas-liquid separator 2.

[0014] Beneficial effects of the utility model:

[0015] The entire system of the utility model is divided into unloading mode and recovery mode. During the unloading mode, the system compresses, condenses and recycles the tetrahydrofuran volatile gas at the breathing port of the ball tank for reuse; during the recovery mode, the system compresses, condenses and recycles the tetrahydrofuran volatile gas in the tank truck for reuse. The entire process does not cause additional gas emissions or losses, achieving the current goal of energy conservation and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the system composition structure of the utility model. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in this specification for understanding and reading by those familiar with this technology. They are not used to limit the conditions for implementation of the utility model and therefore have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed in this utility model without affecting the efficacy and purpose of the utility model. At the same time, terms such as "upper", "lower", "left", "right", and "middle" quoted in this specification are only for the convenience of description and are not used to limit the scope of implementation. Changes or adjustments in their relative relationships should also be considered as the scope of implementation of the utility model without substantially changing the technical content.

[0019] like Figure 1 shown.

[0020] A tetrahydrofuran unloading and recovery system comprises a spherical tank 7 and a single-screw compressor 1. The liquid return port of a tank truck 8 is connected to the liquid inlet of the spherical tank 7, the exhaust port of the tank truck 8 is connected to the air inlet of the single-screw compressor 1, and the liquid replenishing port of the single-screw compressor 1 is connected to the liquid return port of the spherical tank 7; the liquid outlet of the single-screw compressor 1 is connected to the liquid inlet of a gas-liquid separator 2, the liquid discharge port of the gas-liquid separator 2 is connected to another liquid inlet of the spherical tank 7, the exhaust port of the gas-liquid separator 2 is connected to the air inlet of a precooler 3, the exhaust port of the precooler 3 is connected to the exhaust pipe of the tank truck 8 so that excess tetrahydrofuran can be returned to the tank truck, the liquid discharge port of the precooler 3 is connected to the liquid inlet of a condenser 4, the liquid outlet of the condenser 4 is connected to the liquid inlet of a liquid storage tank 6, and the condenser 4 is connected to a low-temperature chilled water inlet pipe and a low-temperature chilled water outlet pipe. The liquid outlet of the liquid storage tank 6 is connected to the third liquid inlet of the spherical tank 7. An aftercooler 5 is installed between the single-screw compressor 1 and the gas-liquid separator 2. The aftercooler 5 is connected to a cooling water inlet and outlet pipes. The gas-liquid separator 2 is also connected to a compressed air source via a pipeline equipped with a ninth on-off valve 34 and a fifth one-way valve 33. The pipeline connecting the tank truck and the single-screw compressor 1 is equipped with a first on-off valve 9, a first pressure sensor 11, a first flowmeter 12, a first air intake filter 13, a second pressure sensor 14, and a first one-way valve 15. In specific implementations, the pipeline connecting the single-screw compressor 1 and the gas-liquid separator 2 is equipped with a second one-way valve 16, a second on-off valve 17, a first temperature sensor 18, and a third pressure sensor 19. The gas-liquid separator 2 is equipped with a first liquid level sensor 20 and a safety valve 21. A second filter 32 and a third on-off valve 31 are installed in the pipeline connecting the gas-liquid separator 2 and the aftercooler 5. A third filter 28, a third check valve 29, and an eighth shutoff valve 35 are installed on the pipeline connecting the liquid outlet of the spherical tank 7 and the liquid inlet of the single-screw compressor 1. A short-circuit pipeline is provided between the pipeline connecting the liquid outlet of the spherical tank 7 and the liquid inlet of the single-screw compressor 1 and the pipeline connecting the aftercooler 5 and the gas-liquid separator 2, and a fourth shutoff valve 36 is installed on the short-circuit pipeline. A second liquid level sensor 26 is installed on the liquid storage tank 6. A fifth shutoff valve 27 is installed on the pipeline connecting the liquid outlet of the liquid storage tank 6 and the spherical tank 7, and a sixth shutoff valve 30 is installed on the liquid outlet pipeline connecting the gas-liquid separator 2. A fourth check valve 22 and a first regulating valve 24 are installed on the pipeline connecting the air outlet of the precooler 3 and the tank truck 8. A seventh shutoff valve 10 is installed on the pipeline connecting the spherical tank 7 and the air inlet of the single-screw compressor 1. A second regulating valve 23 is installed on the pipeline connecting the precooler 3 and the spherical tank 7.

[0021] The working principle and process of this utility model are as follows:

[0022] Before the system starts, it will first perform a self-check. If the liquid level of the first liquid level sensor 20 does not reach the set value, the fourth on-off valve 36 will open for automatic liquid replenishment. If the pressure of the third pressure sensor 19 in the system does not reach the set value, the ninth on-off valve 34 will open for automatic pressure replenishment.

[0023] When the system is in the unloading condition and the self-test is completed, the seventh on-off valve 10 and the first regulating valve 24 are opened, the first on-off valve 9 and the second regulating valve 23 are closed, the single-screw compressor 1 is started, and the second one-way valve 16 and the third on-off valve 31 are opened.

[0024] The tank truck 8 unloads, and the volatile gas in the spherical tank 7 is pressurized by the single-screw compressor 1 and filtered by the second filter 32. After mixing with the solvent sprayed into the compressor cavity, it enters the gas-liquid separator 2. The gas enters the precooler 3 from the upper side of the gas-liquid separator 2, and enters the condenser 4 after precooling. The solvent is condensed in the condenser 4 and discharged into the liquid storage tank 6. The non-condensable steam in the condenser 4 is reheated in the precooler 3 and enters the tank truck 8 until the unloading is completed.

[0025] When the system detects that the unloading is completed, the seventh shut-off valve 10 and the first regulating valve 24 are switched to the closed state, and the first shut-off valve 9 and the second regulating valve 23 are switched to the open state, and the system enters the recovery state.

[0026] The volatile gas in the tank truck 8 is pressurized by the single-screw compressor 1 and filtered by the second filter 32. After mixing with the solvent sprayed into the compressor cavity, it enters the gas-liquid separator 2. The gas enters the precooler 3 from the upper side of the gas-liquid separator 2, and enters the condenser 4 after being cooled. The solvent is condensed in the condenser 4 and discharged into the liquid storage tank 6. The non-condensable steam in the condenser 4 is reheated in the precooler 3 and enters the spherical tank 7 until the recovery is completed.

[0027] In the unloading condition, the first regulating valve 24 and in the recovery condition, the second regulating valve 23 automatically adjusts the opening to stabilize the pressure in the system at the set value to avoid large fluctuations in the system pressure. At the same time, the single-screw compressor adopts variable frequency control to achieve the purpose of energy saving.

[0028] The system is provided with an aftercooler 5, which can cool the solvent used for circulating spray in the system so that the temperature in the system does not exceed 55°C, ensuring safe and stable operation.

[0029] The first liquid level sensor 20 of the gas-liquid separator and the second liquid level sensor 26 of the liquid storage tank 6 are provided with a discharge accumulation function, which can accumulate the recovered amount of tetrahydrofuran solvent.

[0030] When the first liquid level sensor 20 of the gas-liquid separator 2 is higher than the set value, the fourth on-off valve 36 opens and the solvent is discharged into the spherical tank 7. During operation, when the first liquid level sensor 20 of the gas-liquid separator 2 is lower than the set value, the eighth on-off valve 35 opens and liquid is replenished from the inlet of the single-screw compressor 1 without stopping the machine. When the second liquid level sensor 26 of the liquid storage tank is higher than the set value, the fifth on-off valve 27 opens and the solvent is discharged into the spherical tank 7.

[0031] The single-screw compressor 1 air inlet pipeline, air outlet pipeline, liquid replenishment pipeline, air replenishment pipeline and precooler air outlet pipeline are all provided with one-way valves to prevent leakage of tetrahydrofuran volatile gas.

[0032] Filters are installed on the air inlet pipeline, liquid replenishment pipeline and liquid injection pipeline of the single-screw compressor 1 to ensure the cleanliness of the medium entering the single-screw compressor 1, avoid the compressor from getting stuck during operation, and ensure the stability of the system operation.

[0033] There is no additional gas emission or loss during the unloading and recovery processes. During the two processes, the tetrahydrofuran volatile gas in the spherical tank and tank truck is recovered to achieve energy recovery while avoiding environmental pollution.

[0034] The above embodiments are only preferred implementation methods of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and equivalent substitutions can be made without departing from the principles of the present invention. These technical solutions after improvements and equivalent substitutions to the claims of the present invention all fall within the scope of protection of the present invention.

[0035] The parts not involved in the present invention are the same as the existing technology or can be implemented by using the existing technology.

Claims

1. A tetrahydrofuran unloading and recovery system, comprising a spherical tank (7) and a single-screw compressor (1), characterized in that: The liquid return port of the tank truck (8) is connected to the liquid inlet of the spherical tank (7), the exhaust port of the tank truck (8) is connected to the air inlet of the single-screw compressor (1), the liquid replenishing port of the single-screw compressor (1) is connected to the liquid return port of the spherical tank (7); the liquid outlet of the single-screw compressor (1) is connected to the liquid inlet of the gas-liquid separator (2), the liquid discharge port of the gas-liquid separator (2) is connected to the other liquid inlet of the spherical tank (7), and the gas-liquid separator (2) is connected to the liquid inlet of the spherical tank (7). The exhaust port of the cooler (2) is connected to the air inlet of the precooler (3), the exhaust port of the precooler (3) is connected to the exhaust pipe of the tank truck (8) so that excess tetrahydrofuran can be returned to the tank truck, the liquid discharge port of the precooler (3) is connected to the liquid inlet of the condenser (4), the liquid outlet of the condenser (4) is connected to the liquid inlet of the liquid storage tank (6), and the liquid outlet of the liquid storage tank (6) is connected to the third liquid inlet of the spherical tank (7).

2. Tetrahydrofuran unloading and recovery system according to claim 1, is characterized in that: An aftercooler (5) is installed between the single-screw compressor (1) and the gas-liquid separator (2).

3. Tetrahydrofuran unloading and recovery system according to claim 1, is characterized in that: The gas-liquid separator (2) is also connected to a compressed air source via a pipeline.

4. Tetrahydrofuran (THF) unloading and recovery system according to claim 1, is characterized in that: A first shut-off valve (9), a first pressure sensor (11), a first flow meter (12), a first air intake filter (13), a second pressure sensor (14), and a first one-way valve (15) are installed on a pipeline connecting the tank truck and the single-screw compressor (1).

5. The tetrahydrofuran unloading and recovery system according to claim 1, wherein: A second one-way valve (16), a second on-off valve (17), a first temperature sensor (18), and a third pressure sensor (19) are installed on a pipeline connecting the single-screw compressor (1) and the gas-liquid separator (2).

6. The tetrahydrofuran unloading and recovery system according to claim 1, wherein: The gas-liquid separator (2) is equipped with a first liquid level sensor (20) and a safety valve (21).

7. Tetrahydrofuran (THF) unloading and recovery system according to claim 1, is characterized in that: A second filter (32) and a third on-off valve (31) are installed on the pipeline connecting the gas-liquid separator (2) and the aftercooler (5).

8. Tetrahydrofuran (THF) unloading and recovery system according to claim 1, is characterized in that: A third filter (28), a third one-way valve (29) and an eighth shut-off valve (35) are installed on the pipeline connecting the liquid outlet of the spherical tank (7) and the liquid inlet of the single-screw compressor (1); a short-circuit pipeline is provided between the pipeline connecting the liquid outlet of the spherical tank (7) and the liquid inlet of the single-screw compressor (1) and the pipeline connecting the aftercooler (5) and the gas-liquid separator (2), and a fourth shut-off valve (36) is installed on the short-circuit pipeline.

9. The tetrahydrofuran unloading and recovery system according to claim 1, wherein: A second liquid level sensor (26) is installed on the liquid storage tank (6); a fifth on-off valve (27) is installed on the pipeline connecting the liquid outlet of the liquid storage tank (6) and the spherical tank (7); a sixth on-off valve (30) is installed on the liquid outlet pipeline connecting the gas-liquid separator (2); a fourth one-way valve (22) and a first regulating valve (24) are installed on the pipeline connecting the air outlet of the precooler (3) and the tank truck (8); a seventh on-off valve (10) is installed on the pipeline connecting the spherical tank (7) and the air inlet pipe of the single-screw compressor (1); a second regulating valve (23) is installed on the pipeline connecting the precooler (3) and the spherical tank (7); and a ninth on-off valve (34) and a fifth one-way valve (33) are installed on the compressed air supply pipe of the gas-liquid separator (2).

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