Device and method for recycling high-purity liquefied gas

Abstract

The invention relates to the technical field of electronic special gas tail gas recovery, and discloses a high-purity liquefied gas recycling device and method.The device comprises a negative pressure tank, a negative pressure pump, a batch rectifying tower, a refined product buffer tank and a diaphragm compressor which are sequentially connected through pipelines, and a gas inlet of the negative pressure tank is connected with a steel cylinder residual gas pipeline and / or a weighing residual gas pipeline; and an exhaust port of the diaphragm compressor is connected with a steel cylinder to be inflated. According to the device disclosed by the invention, the recovery of filling analysis tail gas and steel cylinder tail gas can be efficiently realized in one set of device, so that the environmental pollution is avoided, the high-quality filling row is also ensured not to be polluted by impurities, the stability of the rear pressure of an instrument is ensured, and the analysis result is prevented from being influenced. The structure and the method are simple, the efficiency is high, and a method and a thought are provided for production improvement and consumption reduction of a production unit.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic special gas tail gas recovery, and particularly relates to a device and method for recycling high-purity liquefied gas. BACKGROUND

[0002] With the development of the semiconductor industry, the use of high-purity electronic special gas (such as high-purity liquefied gas products such as nitrogen trifluoride and silicon tetrafluoride) has increased dramatically. Since such high-purity liquefied gas is often expensive, the liquefied gas needs to be analyzed and detected during the process of being filled into a steel cylinder, and the residual gas in the steel cylinder after use and the residual gas during filling need to be discharged. If these gases cannot be recovered, not only will it cause waste, but also will cause environmental pollution.

[0003] Patent No. CN119289278A discloses a SF6 gas cylinder device, which includes at least two gas cylinders and a charging pipeline. The charging pipeline includes at least two pipeline connectors and at least two connecting pipelines. When performing SF6 gas recovery operations, at least two gas cylinders can be simultaneously pressurized, thereby reducing the number of cylinder replacements and improving work efficiency. However, it can only charge the gas cylinder, and cannot recover the residual gas in the gas cylinder or the residual gas after gas detection, thereby causing waste. SUMMARY

[0004] The purpose of the present application is to provide a device and method for recycling high-purity liquefied gas, which is used to recover residual gas during the analysis and detection or filling process of liquefied gas.

[0005] To achieve the above purpose, the technical solution adopted by the present application is as follows:

[0006] A device for recycling high-purity liquefied gas, comprising a negative pressure tank, a negative pressure pump, an intermittent rectifying column, a fine product buffer tank and a diaphragm compressor connected in sequence through pipelines. The gas inlet of the negative pressure tank is connected with a steel cylinder residual gas pipeline and / or a weighing residual gas pipeline. The gas outlet of the diaphragm compressor is connected with a steel cylinder to be filled.

[0007] Further, a pressure stabilizing tank is further included. The gas outlet of the pressure stabilizing tank is in communication with the gas inlet of the negative pressure tank. The gas inlet of the pressure stabilizing tank is connected with an analysis tail gas pipeline.

[0008] Further, a vacuum pipeline and a high-purity helium pipeline are connected to the pipeline between the diaphragm compressor and the steel cylinder.

[0009] Further, a filling and residual gas discharging pipeline and an analysis pipeline are connected to the pipeline between the diaphragm compressor and the steel cylinder. The filling and residual gas discharging pipeline is in communication with the gas inlet of the negative pressure tank.

[0010] A method for recycling high-purity liquefied gas using the device for recycling high-purity liquefied gas, comprising the following steps:

[0011] Step 1, connecting the steel cylinder with the pipeline at the outlet of the diaphragm compressor;

[0012] Step 2, replacing the residual gas in the steel cylinder and the pipeline at the outlet of the diaphragm compressor;

[0013] Step 3, filling the recycled high-purity liquefied gas into the steel cylinder.

[0014] Further, step 3 comprises:

[0015] Step 3.1, starting the negative pressure pump and the diaphragm compressor, and stabilizing the pressure in the pressure stabilizing tank at -0.08-0.08 MPa, and the pressure range of the negative pressure tank is -0.1-0 MPa.

[0016] Further, step 3 further comprises:

[0017] Step 3.2, the tail gas after instrument analysis enters the tail gas analysis pipeline, and then sequentially flows through the pressure stabilizing tank, the negative pressure tank, the negative pressure pump, the intermittent rectifying column, the fine product buffer tank and the diaphragm compressor, and then enters the instrument through the analysis pipeline for analysis, and after the analysis is qualified, is filled into the steel cylinder.

[0018] Further, step 3 further comprises:

[0019] Step 3.2, the residual gas in the steel cylinder after use enters the negative pressure tank through the steel cylinder residual gas pipeline, or the residual gas after weighing enters the negative pressure tank through the weighing residual gas pipeline, and then sequentially flows through the negative pressure pump, the intermittent rectifying column, the fine product buffer tank and the diaphragm compressor, and then enters the instrument through the analysis pipeline for analysis, and after the analysis is qualified, is filled into the steel cylinder.

[0020] Further, step 1 further comprises:

[0021] The residual gas in the steel cylinder enters the negative pressure tank through the filling residual gas pipeline.

[0022] The positive effects of the present application are:

[0023] This invention utilizes a pressure stabilizing tank to collect the exhaust gas after instrument analysis. Pressure control via the tank ensures the stability of the analysis results while collecting the exhaust gas. A negative pressure tank and pump provide negative pressure for the entire recovery system, and the pump also powers the gas to enter the subsequent batch distillation column. Gas-liquid mass transfer occurs in the column and vessel of the batch distillation column. The product after re-distillation enters a refinement buffer tank for buffering, and then is pressurized by a diaphragm compressor. The pressurized product gas then enters the refinement filling line and is filled into gas cylinders. Ultimately, a single device efficiently recovers both the filling analysis exhaust gas and the gas cylinder exhaust gas, avoiding environmental pollution, ensuring the refinement filling line is not contaminated by impurities, and guaranteeing stable pressure downstream of the instrument, thus preventing the analysis results from being affected. This invention has a simple structure and method, high efficiency, and provides a method and approach for production units to increase production and reduce costs. Attached Figure Description

[0024] Figure 1 This is a system schematic diagram of the present invention;

[0025] In the picture:

[0026] 1. Pressure stabilizing tank; 2. Negative pressure tank; 3. Negative pressure pump; 4. Intermittent distillation column; 5. Refined gas buffer tank; 6. Diaphragm compressor; 7. Refined gas filling drain; 8. Gas cylinder; S1. Analytical tail gas pipeline; S2. Gas cylinder residual gas pipeline; S3. Weighing residual gas pipeline; S5. Filling drain residual gas pipeline; S6. High-purity helium pipeline; S7. Vacuum pipeline; S8. Analytical pipeline. Detailed Implementation

[0027] Example 1

[0028] like Figure 1 As shown, a device for recovering and reusing high-purity liquefied petroleum gas (LPG) includes a pressure stabilizing tank 1, a negative pressure tank 2, a negative pressure pump 3, an intermittent distillation column 4, a refined gas buffer tank 5, and a diaphragm compressor 6, all connected sequentially by pipelines. A refined gas filling manifold 7 is installed on the pipeline at the outlet of the diaphragm compressor 6. A cylinder residual gas pipeline S2 and a weighing residual gas pipeline S3 connect the pipeline between the negative pressure tank 2 and the pressure stabilizing tank 1. The exhaust port at the left end of the refined gas filling manifold 7 is connected to the cylinder 8 to be filled. The outlet of the pressure stabilizing tank 1 is connected to the inlet of the negative pressure tank 2, and the inlet of the pressure stabilizing tank 1 is connected to an analysis tail gas pipeline S1.

[0029] The analysis tail gas pipeline S1 is connected with the exhaust port of the instrument for detection, and is used to introduce the detected gas into the pressure stabilizing tank 1. The pressure stabilizing tank 1 is used to collect the tail gas discharged by the instrument after analysis, and more importantly, to stabilize the pressure of the pipeline after the instrument. If the outlet pressure of the instrument is unstable, the accuracy of the detection of the instrument will be affected. Therefore, the pressure stabilizing tank 1 can ensure the accuracy of the analysis result of the instrument while collecting the tail gas discharged by the instrument. The pressure stabilizing tank 1 is connected with a diaphragm valve arranged thereon, so that the gas pressure in the pressure stabilizing tank 1 is stabilized in the range of -0.08-0.08 MPa. The diaphragm valve is automatically controlled by the pressure. When the pressure rises, the diaphragm valve is opened, and when the pressure decreases, the diaphragm valve is closed, so as to stabilize the pressure of the pressure stabilizing tank 1 in the above range. The cylinder residual gas pipeline S2 is used to connect with the used cylinder, and to introduce the residual gas into the negative pressure tank 2 for recovery.

[0030] The high-purity helium pipeline S6 and the vacuum pipeline S7 are connected with the fine filling row 7.

[0031] The filling row residual gas pipeline S5 and the analysis pipeline S8 are connected with the fine filling row 7, and the filling row residual gas pipeline S5 is communicated with the gas inlet of the negative pressure tank 2.

[0032] The negative pressure tank 2 and the negative pressure pump 3 are used to provide a collection negative pressure, and the gas pressure in the negative pressure tank 2 is stabilized in the range of -0.1-0 MPa, so as to ensure the recovery pressure difference. At the same time, the negative pressure pump 3 also provides power for the gas entering the intermittent rectifying tower 4.

[0033] Under the action of the negative pressure pump 3, the high-purity liquefied gas recovered into the negative pressure tank 2 is transported to the intermittent rectifying tower 4. The intermittent rectifying tower 4 collects the recovered high-purity liquefied gas by cooling, and then vaporizes the high-purity liquefied gas through the heating device at the bottom of the intermittent rectifying tower 4. The gas-liquid phase mass transfer is carried out in the column and the kettle of the intermittent rectifying tower 4. After the second rectification, the high-purity liquefied gas enters the fine buffer tank 5 for buffering, is pressurized by the diaphragm compressor 6, enters the fine filling row 7 after the pressure is increased, and is filled into the cylinder 8.

[0034] The fine buffer tank 5 is used to stabilize the pressure at the inlet of the diaphragm compressor 6. The fine filling row 7 is connected with the high-purity helium pipeline S6, the vacuum pipeline S7 and the analysis pipeline S8.

[0035] Before the cylinder 8 is filled, the pipeline between the diaphragm compressor 6 and the cylinder 8, the fine filling row 7 and the inside of the cylinder 8 are first vacuumized through the vacuum pipeline S7, and then are replaced through the high-purity helium pipeline S6 for three to five times. Then, the pipeline between the diaphragm compressor 6 and the cylinder 8 and the inside of the cylinder 8 are vacuumized, so as to ensure the purity of the gas filled into the cylinder 8. Before the gas enters the cylinder 8, the gas is first introduced into the instrument through the analysis pipeline 8 for analysis, and then is filled after the analysis is qualified. After the filling is completed, the residual gas in the pipeline between the diaphragm compressor 6 and the cylinder 8 is introduced into the negative pressure tank 2 through the filling row residual gas pipeline S5 for recovery.

[0036] Example 2

[0037] A method for recycling high-purity liquefied gas using the high-purity liquefied gas recycling device of Example 1, comprising the following steps:

[0038] Step 1, connect the steel cylinder 8 to the outlet pipe at the left end of the fine filling row 7; the residual gas in the steel cylinder 8 enters the negative pressure tank 2 through the filling row residual gas pipeline S5.

[0039] Step 2, replace the residual gas in the steel cylinder 8, the outlet pipe of the diaphragm compressor 6, and the fine filling row 7.

[0040] Step 3, fill the recycled high-purity liquefied gas into the steel cylinder 8.

[0041] Step 3.1, start the negative pressure pump 3 and the diaphragm compressor 6, and stabilize the pressure in the pressure stabilizing tank 1 at -0.08-0.08 MPa, and the pressure range of the negative pressure tank 2 is -0.1-0 MPa.

[0042] Step 3.2, the tail gas after instrument analysis enters the tail gas analysis pipeline S1, then flows through the pressure stabilizing tank 1, the negative pressure tank 2, the negative pressure pump 3, the intermittent rectifying column 4, the fine buffer tank 5, and the diaphragm compressor 6 in turn, and then enters the instrument through the analysis pipeline S8 for analysis. After passing the analysis, it is filled into the steel cylinder 8.

[0043] Example 3

[0044] A method for recycling high-purity liquefied gas using the high-purity liquefied gas recycling device of Example 1, comprising the following steps:

[0045] Step 1, connect the steel cylinder 8 to the outlet pipe at the left end of the fine filling row 7; the residual gas in the steel cylinder 8 enters the negative pressure tank 2 through the filling row residual gas pipeline S5.

[0046] Step 2, replace the residual gas in the steel cylinder 8, the outlet pipe of the diaphragm compressor 6, and the fine filling row 7.

[0047] Step 3, fill the recycled high-purity liquefied gas into the steel cylinder 8.

[0048] Step 3.1, start the negative pressure pump 3 and the diaphragm compressor 6, and stabilize the pressure in the pressure stabilizing tank 1 at -0.08-0.08 MPa, and the pressure range of the negative pressure tank 2 is -0.1-0 MPa.

[0049] Step 3.2: The residual gas in the cylinder after use enters the negative pressure tank 2 through the cylinder residual gas pipeline S2, or the residual gas after weighing enters the negative pressure tank through the weighing residual gas pipeline S3. Then, it flows sequentially through the negative pressure pump 3, the intermittent distillation column 4, the fine buffer tank 5, and the diaphragm compressor 6, and then enters the instrument for analysis through the analysis pipeline S8. After passing the analysis, it is filled into the cylinder 8.

[0050] The above-described embodiments are detailed and specific, illustrating preferred embodiments of the present invention. They are only used to illustrate the technical ideas and features of the present invention, with the aim of enabling those skilled in the art to understand the content of the present invention and implement it accordingly. However, they are not limited to the present invention, and the patent scope of the present invention cannot be limited by this embodiment alone. That is, any equivalent changes or modifications made to the spirit disclosed in the present invention, without departing from the structure of the present invention, such as local improvements within the system and modifications or transformations between subsystems, are still within the patent scope of the present invention.

Claims

1. An apparatus for recovering and reusing high purity liquefied gas, characterized by comprising: It comprises a negative pressure tank (2), a negative pressure pump (3), an intermittent rectifying tower (4), a fine product buffer tank (5) and a diaphragm compressor (6) connected in sequence through pipelines, the gas inlet of the negative pressure tank (2) is connected with a cylinder residual gas pipeline (S2) and / or a weighing residual gas pipeline (S3), and the gas outlet of the diaphragm compressor (6) is connected with a cylinder (8) to be filled.

2. The device for recovering and reusing high-purity liquefied gas according to claim 1, characterized by It also comprises a pressure stabilizing tank (1), the gas outlet of the pressure stabilizing tank (1) is communicated with the gas inlet of the negative pressure tank (2), and the gas inlet of the pressure stabilizing tank (1) is connected with an analysis tail gas pipeline (S1).

3. The device for recovering and reusing high-purity liquefied gas according to claim 2, characterized by A vacuum pipeline (S7) and a high-purity helium pipeline (S6) are connected to the pipeline between the diaphragm compressor (6) and the cylinder (8).

4. The device for recovering and reusing high-purity liquefied gas according to claim 3, characterized by A filling residual gas discharge pipeline (S5) and an analysis pipeline (S8) are connected to the pipeline between the diaphragm compressor (6) and the cylinder (8), and the filling residual gas discharge pipeline (S5) is communicated with the gas inlet of the negative pressure tank (2).

5. A method for recovering and reusing high purity liquefied gas, characterized by, The device for recycling and reusing high-purity liquefied gas according to claim 4 comprises the following steps: Step 1: connecting the cylinder (8) with the pipeline at the outlet of the diaphragm compressor (6); Step 2: replacing the residual gas in the cylinder (8) and the pipeline at the outlet of the diaphragm compressor (6); Step 3: filling the recycled high-purity liquefied gas into the cylinder (8).

6. The method of claim 5, wherein the high purity liquefied gas is recovered and reused. Step 3 comprises: Step 3.1: starting the negative pressure pump (3) and the diaphragm compressor (6), and stabilizing the pressure in the pressure stabilizing tank (1) at-0.08-0.08 MPa, and the pressure range of the negative pressure tank (2) is-0.1-0 MPa.

7. The method of claim 6, wherein the high purity liquefied gas is recovered and reused. Step 3 also comprises: Step 3.2: the tail gas after instrument analysis enters the tail gas analysis pipeline (S1), and then flows through the pressure stabilizing tank (1), the negative pressure tank (2), the negative pressure pump (3), the intermittent rectifying tower (4), the fine product buffer tank (5) and the diaphragm compressor (6) in sequence, and then enters the instrument through the analysis pipeline (S8) for analysis, and after the analysis is qualified, the tail gas is filled into the cylinder (8).

8. The method of claim 6, wherein the high purity liquefied gas is recovered and reused. Step 3 also comprises: Step 3.2: the residual gas in the used cylinder enters the negative pressure tank (2) through the cylinder residual gas pipeline (S2) or the residual gas after weighing enters the negative pressure tank (2) through the weighing residual gas pipeline (S3), and then flows through the negative pressure pump (3), the intermittent rectifying tower (4), the fine product buffer tank (5) and the diaphragm compressor (6) in sequence, and then enters the instrument through the analysis pipeline (S8) for analysis, and after the analysis is qualified, the residual gas is filled into the cylinder (8).

9. The method of claim 5, wherein the high purity liquefied gas is recovered and reused. Step 1 also comprises: The residual gas in the cylinder (8) enters the negative pressure tank (2) through the filling residual gas discharge pipeline (S5).

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