High-purity high-pressure liquid carbon dioxide conveying system

Abstract

The utility model discloses a high-purity high-pressure liquid carbon dioxide delivery system which comprises a gas inlet pipeline, a purification pipeline, a condenser, a pressurization pipeline and a heating pipeline which are sequentially connected, the purification pipeline is provided with a gas purifier, and a gas outlet, connected with the pressurization pipeline, of the condenser is further connected with a gas exhaust pipeline. And a pneumatic diaphragm valve and a first needle valve are sequentially arranged on the exhaust pipeline according to the flow direction. The conveying system disclosed by the utility model has the advantage that the purity of a carbon dioxide inlet is not easy to decrease after long-time operation, and the use requirements of wet-process equipment are ensured.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of substance purification pressurization, and relates to a high-purity high-pressure liquid carbon dioxide conveying system. BACKGROUND

[0002] With the gradual reduction of integrated circuit feature size, the aspect ratio of device structure is increased, and conventional wet etching has the defects of poor anisotropy, serious structure collapse, and unobvious deep groove etching effect, while supercritical carbon dioxide has been used for wafer cleaning and has a great development trend due to its low viscosity, zero surface tension, and high diffusion coefficient. Therefore, the inlet purity of carbon dioxide required by the wet etching equipment is 99.9999999%, the pressure is 200Bar, and the flow is 30NM 3 / H.

[0003] However, according to the national standard GB / T43772-2024, the highest purity of carbon dioxide currently supplied on the market is 99.9995%, and the source pressure is at most 50Bar.

[0004] Therefore, in the prior art, the carbon dioxide needs to be purified and pressurized by a conveying system at the use site, and the specific method is to further remove impurities by using a purifier, and then sequentially perform liquefaction, pressure increase, and heating to reach the required pressure and temperature values.

[0005] However, it is found in actual operation that although the purity of carbon dioxide has reached 99.9999999% after re-purification, there are still trace amounts of impurities (such as carbon monoxide and nitrogen monoxide). At the beginning, these impurities have little effect, but after a long time of operation, the impurities will accumulate in the pipeline and increase, and when a certain amount of impurities accumulates, the inlet purity of carbon dioxide (i.e. the purity of carbon dioxide entering the use equipment) will decrease, which cannot meet the use requirements. INVENTION CONTENTS

[0006] The technical problem to be solved by the utility model is to provide a high-purity high-pressure liquid carbon dioxide conveying system which can be operated for a long time and the inlet purity of carbon dioxide does not easily decrease, so as to overcome the deficiencies of the prior art.

[0007] To solve the above technical problems, the utility model adopts the following technical scheme:

[0008] A high-purity high-pressure liquid carbon dioxide conveying system, comprising a gas inlet pipeline, a purification pipeline, a condenser, a pressurizing pipeline, and a heating pipeline connected in sequence, wherein the purification pipeline is provided with a gas purifier, characterized in that an exhaust pipeline is further connected to the gas outlet of the condenser connected with the pressurizing pipeline, and a pneumatic diaphragm valve and a first needle valve are sequentially arranged on the exhaust pipeline in the flow direction.

[0009] By setting the exhaust pipeline on the air outlet of the condenser, and setting the pneumatic diaphragm valve on the exhaust pipeline, the exhaust flow is controlled by the first needle valve, so that after the purified carbon dioxide gas is condensed, the uncondensed impurity gas will slowly accumulate, when the impurity gas accumulates to a pressure exceeding the set pressure of the pneumatic diaphragm valve, the pneumatic diaphragm valve will automatically open, allowing the accumulated impurity gas to be discharged outside the pipeline, and the impurity gas will not accumulate in the pipeline, so that the carbon dioxide inlet purity will not easily decrease after the conveying system runs for a long time.

[0010] In the utility model, the first manual diaphragm valve and the second manual diaphragm valve are respectively arranged at the front position and the rear position of the gas purifier in the purification pipeline, the hydrogen input pipeline is connected to the pipeline between the gas purifier and the first manual diaphragm valve, and the hydrogen discharge pipeline is connected to the pipeline between the gas purifier and the second manual diaphragm valve, so that the gas purifier can be regenerated by hydrogen at regular intervals, the activity of the gas purifier is maintained, and the purification effect on the carbon dioxide gas is ensured.

[0011] In the utility model, the pipeline in each pipeline is polished 316L stainless steel pipeline, the roughness of the inner surface of the pipeline made of this material is less than or equal to 0.1 microns, so that small particles are difficult to adhere to the inner wall of the pipeline, and the carbon dioxide inlet purity is not easily decreased after the conveying system runs for a long time.

[0012] In the utility model, the first pressure transmitter, the third manual diaphragm valve, the gaseous pressure reducer and the flow measurer are sequentially connected to the gas inlet pipeline in sequence.

[0013] In the utility model, the second pressure transmitter, the fourth manual diaphragm valve, the booster pump, the third pressure transmitter and the filter are sequentially connected to the pressure pipeline in sequence.

[0014] In the utility model, the heating pipeline has the heater.

[0015] In the utility model, the pipeline between the heater and the filter is further connected with the sampling pipeline.

[0016] In the utility model, the pipeline between the heater and the filter is further connected with the pressure relief pipeline and the safety discharge pipeline, and the system is protected.

[0017] The conveying system has the advantages that the purity of the carbon dioxide inlet is not prone to decrease after long-time operation, and the requirements for use of the wet process equipment are ensured. BRIEF DESCRIPTION OF DRAWINGS

[0018] The utility model will be explained in detail below in combination with the drawings:

[0019] Figure 1 The utility model discloses a pipeline diagram. DETAILED DESCRIPTION

[0020] As Figure 1 The high-purity high-pressure liquid carbon dioxide conveying system comprises, in sequence according to a flow direction, a gas inlet pipeline 100, a purification pipeline 200, a condenser 300, a pressure boosting pipeline 400 and a heating pipeline 500.

[0021] The purification pipeline 200 comprises, in sequence according to a flow direction, a first manual diaphragm valve 201, a gas purifier 202 and a second manual diaphragm valve 203. The gas purifier 202 is a mature product in the prior art and can be directly purchased from the market. The purifier 202 is filled with high-performance adsorbent (aluminum oxide is used as the adsorbent in the embodiment), selectively adsorbs impurities by using the principle of physical adsorption, and can purify carbon dioxide gas with a purity of 99.9995% to 99.9999999%.

[0022] The gas inlet pipeline 100 comprises, in sequence according to a flow direction, a first pressure transmitter 101, a third manual diaphragm valve 102, a gaseous pressure reducer 103 and a flow measurer 104. The inlet of the first pressure transmitter 101 is connected with a carbon dioxide storage tank 001 transported, so as to measure the pressure of the entering carbon dioxide gas. The third manual diaphragm valve 102 is used for controlling the entering of the carbon dioxide gas. The gaseous pressure reducer 103 is used for reducing the pressure of the input carbon dioxide gas to the required inlet pressure for purification. The flow measurer 104 measures the inlet flow of the carbon dioxide gas.

[0023] The condenser 300 is used for cooling the gaseous carbon dioxide with a purity of 99.9999999% to liquid carbon dioxide with a purity of 99.9999999%.

[0024] The pressurizing pipeline 400 comprises, in sequence, a second pressure transmitter 401, a fourth manual diaphragm valve 402, a pressurizing pump 403, a third pressure transmitter 404 and a filter 405. The second pressure transmitter 401 is used to detect the pressure of the liquid carbon dioxide from the condenser 300. The fourth manual diaphragm valve 402 is used to control the input of the liquid carbon dioxide to the pressurizing pump 403. The pressurizing pump 403 is used to pressurize the liquid carbon dioxide to 200 Bar. The third pressure transmitter 404 is used to monitor the pressure of the pressurized liquid carbon dioxide. The filter 405 is used to filter the liquid carbon dioxide, further obtaining pure liquid carbon dioxide.

[0025] In the utility model, the gas outlet of the condenser 300 connected with the pressurizing pipeline 400 is further connected with an exhaust pipeline 600. The exhaust pipeline 600 is sequentially provided with a pneumatic diaphragm valve 601 and a first needle valve 602 in sequence. By arranging the exhaust pipeline on the gas outlet of the condenser, and arranging the pneumatic diaphragm valve 601 on the exhaust pipeline, and controlling the exhaust flow by the first needle valve 602, after the purified carbon dioxide gas is condensed, the uncondensed impurity gas is accumulated slowly. When the impurity gas accumulation pressure exceeds the set pressure of the pneumatic diaphragm valve (the set pressure is 35 Bar in the embodiment), the pneumatic diaphragm valve is automatically opened, and the accumulated impurity gas is discharged outside the pipeline, and the impurity gas is not accumulated in the pipeline, so that the carbon dioxide inlet purity is not easily reduced after the conveying system is operated for a long time.

[0026] The pipeline between the gas purifier 202 and the first manual diaphragm valve 201 is connected with a hydrogen input pipeline 710, and the pipeline between the gas purifier 202 and the second manual diaphragm valve 203 is connected with a hydrogen exhaust pipeline 720. In the utility model, the purification pipeline 200 is provided with two pipelines, one for standby and one for use. The hydrogen input pipeline 710 realizes the switching of hydrogen input by arranging a plurality of air inlet manual diaphragm valves 711, and the hydrogen exhaust pipeline 720 realizes the switching of hydrogen exhaust by arranging a plurality of exhaust manual diaphragm valves 721. In this way, the gas purifier 202 can be regenerated periodically by using hydrogen, the activity of the gas purifier is maintained, and the purification effect of the carbon dioxide gas is ensured.

[0027] The heating pipeline 500 comprises, in sequence, a heater 501 and a seventh manual diaphragm valve 502. The heater 501 is used to heat the pressurized liquid carbon dioxide to room temperature to generate room temperature liquid carbon dioxide. The seventh manual diaphragm valve 502 is used to connect a wet process equipment, and is used to control the supply of the required high-purity high-pressure room temperature liquid carbon dioxide to the wet process equipment.

[0028] The pipeline between the heater 501 and the filter 405 is further connected with a sampling pipeline 810, a pressure relief pipeline 820 and a safety discharge pipeline 830.

[0029] The sampling pipeline 810 can take gas or liquid in the conveying process to measure the impurity content in the gas. The sampling pipeline 810 includes a fifth manual diaphragm valve 811, a second needle valve 812, a pressure reducing valve 813, a pressure gauge 814 and a sixth manual diaphragm valve 815 connected in sequence according to the flow direction. The pressure relief pipeline 820 is provided with a pressure relief valve 821. When the pressure in the pipeline exceeds the set pressure of the pressure relief valve 821 (the set pressure in the embodiment is 210 Bar), the pressure relief valve 821 will play a pressure relief role. The safety discharge pipeline 830 includes an eighth manual diaphragm valve 831 and a safety valve 832 connected in sequence according to the flow direction. The eighth manual diaphragm valve 831 is always open when the system is working. Once the pressure in the system pipeline exceeds the set pressure of the safety valve 832 (the set pressure in the embodiment is 220 Bar), the safety valve 830 is automatically opened to play a role in protecting the system.

[0030] In the utility model, the exhaust pipeline 600 is provided with a ninth manual diaphragm valve 603 in front of the pneumatic diaphragm valve 601. The ninth manual diaphragm valve 603 is open when the conveying system works. If the pneumatic diaphragm valve 601 or the first needle valve 602 is damaged and loses the effect, the ninth manual diaphragm valve 603 is closed.

[0031] In the utility model, the pipeline in each pipeline is polished 316L stainless steel pipeline. The pipeline of this material has an inner surface roughness less than or equal to 0.1 microns, which ensures that small particles are difficult to adhere to the inner wall of the pipeline, and further ensures that the conveying system runs for a long time, and the carbon dioxide inlet purity does not easily decrease.

[0032] It can be seen from the above detailed introduction that the conveying system of the utility model has the advantages that the carbon dioxide inlet purity does not easily decrease after long-time operation, and the requirements of the wet process equipment are ensured.

Claims

1. A high-purity high-pressure liquid carbon dioxide delivery system comprising a gas inlet line, a purification line, a condenser, a pressure boosting line and a heating line connected in series, the purification line having a gas purifier, characterized in that, The gas outlet of the condenser connected with the booster pipeline is further connected with an exhaust pipeline, and the exhaust pipeline is sequentially provided with a pneumatic diaphragm valve and a first needle valve in sequence according to the flow direction.

2. The high-purity high-pressure liquid carbon dioxide delivery system of claim 1, wherein, The first and second manual diaphragm valves are respectively arranged at the front and rear positions of the gas purifier in the purification pipeline, the hydrogen input pipeline is connected to the pipeline between the gas purifier and the first manual diaphragm valve, and the hydrogen exhaust pipeline is connected to the pipeline between the gas purifier and the second manual diaphragm valve.

3. The high-purity high-pressure liquid carbon dioxide delivery system of claim 1, wherein, The pipeline in each pipeline is made of polished 316L stainless steel pipeline.

4. The high-purity high-pressure liquid carbon dioxide delivery system of claim 1, wherein, The gas inlet pipeline is sequentially connected with a first pressure transmitter, a third manual diaphragm valve, a gaseous pressure reducer and a flow measurer in sequence according to the flow direction.

5. The high-purity high-pressure liquid carbon dioxide delivery system of claim 1, wherein, The booster pipeline is sequentially connected with a second pressure transmitter, a fourth manual diaphragm valve, a booster pump, a third pressure transmitter and a filter in sequence according to the flow direction.

6. The high-purity high-pressure liquid carbon dioxide delivery system of claim 5, wherein, The heating pipeline has a heater.

7. The high-purity high-pressure liquid carbon dioxide delivery system of claim 6, wherein, The pipeline between the heater and the filter is further connected with a sampling pipeline.

8. The high-purity high-pressure liquid carbon dioxide delivery system of claim 7, wherein, The sampling pipeline is sequentially connected with a fifth manual diaphragm valve, a second needle valve, a pressure reducing valve, a pressure gauge and a sixth manual diaphragm valve in sequence according to the flow direction.

9. The high-purity high-pressure liquid carbon dioxide delivery system of claim 6, wherein, The pipeline between the heater and the filter is further connected with a pressure relief pipeline and a safety discharge pipeline.

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