Water washing device for pentafluoroethane

Abstract

The utility model belongs to the technical field of post-treatment devices of chemical products, and particularly relates to a pentafluoroethane washing device. The pentafluoroethane washing device comprises a liquid phase washing tower, the upper portion of the liquid phase washing tower is connected with a crude product R125 feeding pipe, a feeding cooler is arranged on the crude product R125 feeding pipe, the lower portion of the liquid phase washing tower is connected with a purified water feeding pipe, a water inlet cooler is arranged on the purified water feeding pipe, a tower bottom pipeline of the liquid phase washing tower is divided into two paths, one path is connected with the alkali cooler, the other path is connected with the No.1 alkali separator, a cooling material outlet of the alkali cooler is connected with the No.1 alkali separator, and a material outlet of the No.1 alkali separator is connected with the No.2 alkali separator. According to the pentafluoroethane washing device provided by the utility model, the washing temperature is controlled, the stability of system operation is maintained, and the gasification of R125 is inhibited to the maximum extent, so that the recovery rate of products and the economic benefit of the production process are remarkably improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of the post-processing device of chemical product, concretely relates to the water washing device of pentafluoroethane. BACKGROUND

[0002] Pentafluoroethane (R125) as an important fluorinated chemical product, is widely used in refrigerant and fire extinguishing agent and other fields. In its production process, the liquid phase crude product R125 obtained by crude product tower separation usually contains various acid impurities, such as hydrogen chloride (HCl), hydrogen fluoride (HF) and the like. In order to remove these acid substances, the purification process combining water washing and alkali washing is often used in industrial production.

[0003] The traditional process flow is that the liquid phase R125 collected from the crude product tower is sent into the liquid phase water washing tower, and the pure soft water from the top of the tower is contacted and washed in countercurrent. Through this process, most of the water-soluble acid substances are transferred to the water phase. After washing, the mixture is static layered in the tower or subsequent separation equipment: the upper layer is waste acid water dissolved with acid substances, which is discharged from the top to the waste acid storage tank; the lower layer is the R125 crude product purified initially, which is discharged from the bottom, and then mixed with lye into a mixing pump to complete the subsequent alkali washing neutralization reaction.

[0004] However, the above-mentioned traditional water washing process has a significant technical defect. Since R125 itself is a liquefied gas with low boiling point, its stability is significantly affected by temperature. In the water washing process, the temperature of the pure water as the washing medium will fluctuate with the change of the ambient air temperature. When the water temperature rises, a large amount of R125 in the liquid phase in the tower will be gasified. The gasification of R125 not only causes the system pressure to rise, but also causes two serious consequences: first, a large amount of gasified R125 will be discharged from the system with the waste acid water from the top of the tower, directly causing product loss, resulting in the reduction of the recovery rate of pentafluoroethane; second, the unstable gas-liquid two-phase flow will destroy the normal flow and mass transfer state in the tower, affecting the water washing efficiency.

[0005] While existing technologies include various devices for treating chemical waste gas, such as the Chinese patent CN223042490U which discloses a "Fluorochemical Silicon Tetrafluoride Pollutant Waste Gas Recovery and Treatment Device," this device uses a spray circulation system in its water washing recovery tower to wash the waste gas. However, its design is primarily for the absorption and purification of gaseous pollutants, and its working medium and operating conditions are geared towards gas treatment. This device is unsuitable for washing and purifying liquid-phase R125. First, its inlet is designed as a waste gas inlet, making it unsuitable for the direct feeding and distribution of liquid materials. Second, the internal circulation and spray system of the water washing tower are designed to wash the gas with liquid, rather than achieving countercurrent contact and efficient separation of the liquid and liquid phases. Most importantly, this device does not consider or control the temperature of the washing water, failing to address the core issue of R125 vaporization caused by water temperature fluctuations. Therefore, existing technologies lack a dedicated pentafluoroethane water washing device that can effectively and stably operate, prevent R125 vaporization, and improve product recovery rates. Utility Model Content

[0006] The technical problem to be solved by this utility model is to overcome the above-mentioned defects in the existing technology and provide a water washing device for pentafluoroethane, which controls the water washing temperature, maintains the stability of system operation, and suppresses the vaporization of R125 to the maximum extent, thereby significantly improving the product recovery rate and the economic benefits of the production process.

[0007] The pentafluoroethane washing device includes a liquid phase washing tower. The upper part of the liquid phase washing tower is connected to a crude R125 feed pipe, and a feed cooler is installed on the crude R125 feed pipe. The lower part of the liquid phase washing tower is connected to a pure water feed pipe, and a water inlet cooler is installed on the pure water feed pipe. The bottom discharge pipe of the liquid phase washing tower is divided into two paths: one path is connected to an alkali cooler, and the other path is connected to a No. 1 alkali separator. The cooled material outlet of the alkali cooler is connected to the No. 1 alkali separator, and the material outlet of the No. 1 alkali separator is connected to the No. 2 alkali separator.

[0008] Preferably, a No. 1 feed booster pump is connected to the pipeline connecting the feed cooler and the liquid phase water washing tower.

[0009] Preferably, a No. 2 feed booster pump is connected to the pipeline connecting the feed cooler and the liquid phase water washing tower.

[0010] Preferably, the pipeline connecting the bottom of the liquid phase water washing tower to the No. 1 alkali separator is connected to the No. 1 alkali circulation pump.

[0011] Preferably, the bottom of the liquid phase water washing tower is connected to the pipeline connecting the No. 1 alkali separator, and the No. 2 alkali circulation pump is connected.

[0012] Preferably, a buffer tank is connected to the top pipeline of the liquid phase water washing tower.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] This invention relates to a pentafluoroethane washing device. By installing precoolers for crude R125 and purified water, the feed temperature is reduced, enhancing mass transfer efficiency and suppressing exothermic reactions, resulting in stable operation and significantly improved impurity removal efficiency. The key pump units are configured with one operating and one standby, allowing seamless switching in case of pump failure, ensuring continuous and uninterrupted washing and improving production reliability. A two-stage series alkali separator is used for deep gas-liquid separation of wastewater, effectively recovering entrained R125 products, reducing losses and lowering the wastewater treatment load. A buffer tank at the top of the tower effectively smooths system pressure fluctuations, ensuring operational safety and preventing disordered material discharge. Through reasonable process design and energy utilization, the device achieves tiered material treatment, realizing energy saving and consumption reduction. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the pentafluoroethane washing device of this utility model.

[0016] In the diagram: 1. Inlet water cooler; 2. Liquid phase water washing tower; 3. Buffer tank; 4. Alkali cooler; 5. Alkali separator No. 1; 6. Alkali separator No. 2; 7. Alkali circulation pump No. 1; 8. Alkali circulation pump No. 2; 9. Feed cooler; 10. Feed booster pump No. 1; 11. Feed booster pump No. 2; 12. Crude product R125 feed pipe; 13. Pure water feed pipe. Detailed Implementation

[0017] The present invention will be further described below with reference to specific embodiments.

[0018] like Figure 1 As shown, the pentafluoroethane washing device includes a liquid phase washing tower 2. The upper part of the liquid phase washing tower 2 is connected to a crude R125 feed pipe 12, and a feed cooler 9 is installed on the crude R125 feed pipe 12. The lower part of the liquid phase washing tower 2 is connected to a pure water feed pipe 13, and a water inlet cooler 1 is installed on the pure water feed pipe 13. The bottom discharge pipe of the liquid phase washing tower 2 is divided into two paths, one of which is connected to an alkali cooler 4, and the other of which is connected to an alkali separator 5. The cooled material outlet of the alkali cooler 4 is connected to the alkali separator 5, and the material outlet of the alkali separator 5 is connected to the alkali separator 6.

[0019] Feed booster pump 10 is connected to the pipeline connecting the feed cooler 9 and the liquid phase water washing tower 2.

[0020] A feed booster pump 11 is connected to the pipeline connecting the feed cooler 9 and the liquid phase water washing tower 2.

[0021] A first alkali liquid circulating pump 7 is connected to the pipeline connecting the bottom of the liquid phase water washing tower 2 and the first alkali separator 5.

[0022] A second alkali liquid circulating pump 8 is connected to the pipeline connecting the bottom of the liquid phase water washing tower 2 and the first alkali separator 5.

[0023] A buffer tank 3 is connected to the top pipeline of the liquid phase water washing tower 2.

[0024] The working process of the utility model is as follows: the crude product R125 enters the liquid phase water washing tower 2 through the crude product R125 feeding pipe 12, is cooled by the feeding cooler 9 first, is pressurized by the first feeding booster pump 10 (or the standby pump, the second feeding booster pump 11), and then enters the tower from the upper part of the liquid phase water washing tower 2.At the same time, the pure water is cooled by the water feeding cooler 1 after passing through the pure water feeding pipe 13, and then enters the tower from the lower part of the liquid phase water washing tower 2.In the tower, the crude product R125 is fully contacted with the cooled pure water, the acidic impurities in the crude product are dissolved in the water to form an acidic solution, and the liquid phase R125 layer and the waste acid are separated in the tower, the upper waste acid is extracted and then enters the buffer tank 3, so that the waste acid is effectively removed, the lower liquid phase R125 is extracted by the first alkali liquid circulating pump 7 (or the standby pump, the second alkali liquid circulating pump 8), is sent to the first alkali separator 5, the gas phase is cooled by the alkali cooler 4, is recycled into the alkali separator 5 for treatment, a small part of the gas phase is treated by the second alkali separator 6, and then the purified liquid phase R125 is extracted from the first alkali separator 5 and the second alkali separator 6.

Claims

1. A water scrubbing apparatus for pentafluoroethane, characterized by: The liquid phase water washing tower (2) is connected with a crude product R125 feeding pipe (12) at the upper part, a feeding cooler (9) is arranged on the crude product R125 feeding pipe (12), the liquid phase water washing tower (2) is connected with a pure water feeding pipe (13) at the lower part, a water feeding cooler (1) is arranged on the pure water feeding pipe (13), the bottom discharging pipe of the liquid phase water washing tower (2) is divided into two routes, one route is connected with an alkali cooler (4), the other route is connected with a No. 1 alkali separator (5), the cooling material outlet of the alkali cooler (4) is connected with the No. 1 alkali separator (5), the material outlet of the No. 1 alkali separator (5) is connected with a No. 2 alkali separator (6).

2. The apparatus for washing pentafluoroethane according to claim 1, characterized by: A No. 1 feeding booster pump (10) is connected on the pipeline connecting the feeding cooler (9) with the liquid phase water washing tower (2).

3. The apparatus for washing pentafluoroethane according to claim 2, characterized by: A No. 2 feeding booster pump (11) is connected on the pipeline connecting the feeding cooler (9) with the liquid phase water washing tower (2).

4. The apparatus for washing pentafluoroethane according to claim 1, wherein: A No. 1 alkali liquid circulating pump (7) is connected on the pipeline connecting the bottom of the liquid phase water washing tower (2) with the No. 1 alkali separator (5).

5. The apparatus for washing pentafluoroethane according to claim 4, characterized by: A No. 2 alkali liquid circulating pump (8) is connected on the pipeline connecting the bottom of the liquid phase water washing tower (2) with the No. 1 alkali separator (5).

6. The apparatus for washing pentafluoroethane according to claim 1, wherein: A buffer tank (3) is connected on the top pipeline of the liquid phase water washing tower (2).

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