Device for preparing sulfur dioxide with purity of 5N

Abstract

The utility model relates to the technical field of sulfur dioxide purification, in particular to a device for preparing sulfur dioxide with the purity of 5N. The device comprises a raw material tank, a vaporizer, an adsorption system, a filtering system, a liquefaction collecting tank, a rectifying tower and a collecting system which are communicated in sequence, a condenser is arranged at the top of the rectifying tower, and a heating circulator is arranged at the bottom of the rectifying tower; the refrigerating machine is communicated with the vaporizer, the liquefaction collecting tank and the condenser; the adsorption system comprises n adsorbers; n is greater than or equal to 1, and when n is equal to 1, the adsorber comprises multiple layers of adsorbents which are filled in a layered manner; the types of the adsorbents in each layer are different; the filtering system comprises m precision filters which are connected in series; m is greater than or equal to 1. And an online analysis instrument is arranged at the top of the rectifying tower. The device is provided with a multi-stage adsorber, a filtering device and a rectifying tower, so that impurities in sulfur dioxide can be effectively removed, and high-purity sulfur dioxide is obtained.

Description

Technical Field

[0001] The utility model relates to the technical field of sulfur dioxide purification, in particular to a device for preparing 5N purity sulfur dioxide. Background Art

[0002] With the development of advanced semiconductor process technology, people have found that sulfur dioxide has higher etching selectivity, less damage to the mask dielectric layer, and higher etching accuracy than fluorocarbon etching gases, and is particularly suitable for advanced process manufacturing below 28nm. At present, sulfur dioxide on the domestic market is basically industrial-grade purity, containing a lot of other impurities, lacking stable and mature high-purity sulfur dioxide batch production technology, and cannot meet the domestic semiconductor and optoelectronics microelectronics industry's demand for high-purity sulfur dioxide products. Summary of the invention

[0003] In view of this, the purpose of the utility model is to provide a device for preparing 5N purity sulfur dioxide. The device provided by the utility model can prepare 5N purity sulfur dioxide.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] The utility model provides a device for preparing 5N purity sulfur dioxide, comprising a raw material tank 1, a vaporizer 2, an adsorption system 3, a filtering system 4, a liquefaction collection tank 5, a distillation tower 6 and a collection system 7 which are connected in sequence; a condenser 21 is arranged on the top of the distillation tower 6, and a heating circulator 18 is arranged on the bottom;

[0006] A refrigerator 19 connected to the vaporizer 2, the liquefied collection tank 5, and the condenser 21; the adsorption system 3 includes n adsorbers; n≥1, when n=1, the adsorbers include multiple layers of adsorbents filled in layers; the types of adsorbents in each layer are different; the filtration system 4 includes m precision filters connected in series; m≥1.

[0007] Preferably, the collection system 7 comprises a product tank 8, a filling pump 9 and a cylinder 14 which are connected in sequence;

[0008] Preferably, a recovery tank 10 connected to the top of the distillation tower 6 is also included.

[0009] Preferably, it also includes a tail gas treatment tower 11 connected to the top and bottom of the distillation tower 6 and the adsorption system 3 through pipelines;

[0010] An inert gas storage tank 15 whose outlet is connected to the inlet of the vaporizer 2;

[0011] An automatic control system 16 and an emergency stop control system 17 communicated with the device via electrical signals;

[0012] The connecting pipeline between the adsorption system 3 and the tail gas treatment tower 11 also includes a vacuum pump 20 .

[0013] Preferably, the online analytical instrument includes a helium ionization gas chromatograph 12 and an electrolytic moisture analyzer 13 .

[0014] Preferably, the filtration accuracy of the precision filter is 0.003-10 μm.

[0015] Preferably, the adsorbent includes one or more of activated carbon, molecular sieve, silica gel, alumina and high molecular porous polymer.

[0016] The utility model provides a device for preparing 5N pure sulfur dioxide, comprising a raw material tank 1, a vaporizer 2, an adsorption system 3, a filtering system 4, a liquefaction collection tank 5, a distillation tower 6 and a collection system 7 connected in sequence; a condenser 21 is arranged on the top of the distillation tower 6, and a heating circulator 18 is arranged on the bottom; a refrigerator 19 connected to the vaporizer 2, the liquefaction collection tank 5 and the condenser 21; the adsorption system 3 comprises n adsorbers; n≥1, when n=1, the adsorbers comprise multi-layered adsorbents; the types of adsorbents in each layer are different; the filtering system 4 comprises m precision filters connected in series; m≥1. An online analyzer is arranged on the top of the distillation tower 6. The device is provided with multi-stage adsorbers, filtering devices and distillation towers, which can effectively remove impurities in sulfur dioxide and obtain high-purity sulfur dioxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The utility model provides a device for preparing 5N purity sulfur dioxide, which includes: 1-raw material tank, 2-vaporizer, 3-adsorption system, 4-filtration system, 5-liquefaction collection tank, 6-distillation tower, 7-collection system, 8-product tank, 9-filling pump, 10-recovery tank, 11-tail gas treatment tower, 12-helium ionization gas chromatograph, 13-electrolytic moisture meter, 14-steel cylinder, 15-inert gas storage tank, 16-automatic control system, 17-emergency stop control system, 18-heating circulator, 19-refrigeration machine, 20-vacuum pump, 21-condenser. DETAILED DESCRIPTION

[0018] The utility model provides a device for preparing 5N purity sulfur dioxide, comprising a raw material tank 1, a vaporizer 2, an adsorption system 3, a filtering system 4, a liquefaction collection tank 5, a distillation tower 6 and a collection system 7 which are connected in sequence; a condenser 21 is arranged on the top of the distillation tower 6, and a heating circulator 18 is arranged on the bottom;

[0019] A refrigerator 19 connected to the vaporizer 2, the liquefied collection tank 5, and the condenser 21;

[0020] The adsorption system 3 includes n adsorbers; n≥1, when n=1, the adsorber includes multiple layers of adsorbents loaded in layers; the type of adsorbent in each layer is different;

[0021] The filtering system 4 includes m precision filters connected in series; m≥1.

[0022] An online analysis instrument is arranged on the top of the distillation tower 6 .

[0023] like Figure 1 As shown, the device for preparing 5N purity sulfur dioxide provided by the utility model comprises a raw material tank 1, a vaporizer 2 connected to the raw material tank 1, and an adsorption system 3 connected to the vaporizer 2.

[0024] In the present invention, the adsorption system 3 includes n adsorbers, where n≥1.

[0025] In the present invention, when n>1, the adsorbers are connected in parallel or in series, and the adsorbents in the adsorbers can be one or more. In the present invention, when n>1, an automatic pneumatic valve is preferably provided on the connecting pipe of the adsorber. In the present invention, when n=1, the adsorber includes multiple layers of adsorbents loaded in layers; each layer of adsorbent is of different types. In the present invention, the multiple layers of adsorbents are preferably 2 layers.

[0026] In the present invention, the adsorbent preferably includes one or more of activated carbon, molecular sieve, silica gel, alumina and high molecular porous polymer, more preferably activated carbon or molecular sieve. In the present invention, the activated carbon preferably includes wood activated carbon, coal activated carbon, polymer synthetic activated carbon or asphalt petroleum coke activated carbon, and the wood activated carbon preferably includes 3-5 mm granular coconut shell activated carbon. In the present invention, before the activated carbon is used, it is preferably activated in an inert atmosphere. The activation temperature is preferably 100-500°C, more preferably 300°C; the time is preferably 8h.

[0027] In the present invention, the molecular sieve preferably includes A-type molecular sieve, X-type molecular sieve, Y-type molecular sieve or zeolite molecular sieve; the A-type molecular sieve preferably includes 3A molecular sieve and / or 5A molecular sieve. In the present invention, the molecular sieve is preferably activated in an inert atmosphere before use; the activation temperature is preferably 200-500°C, more preferably 350°C, and the time is preferably 8h.

[0028] In the utility model, the adsorption system can remove sulfide impurities, hydrocarbon impurities, water and carbon dioxide impurities in sulfur dioxide.

[0029] In the present invention, the device for preparing 5N purity sulfur dioxide provided by the present invention comprises a filtering system 4 connected to an adsorption system 3 .

[0030] In the present invention, the filtration system 4 comprises m precision filters connected in series, and the filtration accuracy of the precision filters is preferably 0.003-10 μm, more preferably 0.003-0.1 μm, and further preferably 0.01 μm. In the present invention, m≥1, preferably 1-3.

[0031] In the present invention, the filtering system removes solid particles.

[0032] In the present invention, the device for preparing 5N pure sulfur dioxide provided by the present invention comprises a liquefaction collection tank 5 connected to a filtering system 4, and a distillation tower 6 connected to the liquefaction collection tank 5. In the present invention, a condenser 21 is provided at the top of the distillation tower 6, and a heating circulator 18 is provided at the bottom; in the present invention, an online analysis instrument is provided at the top of the distillation tower 6; the online analysis instrument preferably comprises a helium ionization gas chromatograph 12 and an electrolytic moisture meter 13. In the present invention, the connecting pipes between the distillation tower 6 and the online analysis instrument, and the connecting pipes between the distillation tower 6 and the collection system 7 are preferably provided with automatic pneumatic valves.

[0033] The device for preparing 5N purity sulfur dioxide provided by the utility model comprises a collection system 7 connected to a distillation tower 6. In the utility model, the collection system 7 preferably comprises a product tank 8, a filling pump 9 and a steel cylinder 14 connected in sequence. In the utility model, the pipeline connecting the distillation tower 6 and the product tank 8 is preferably provided with an automatic pneumatic valve.

[0034] The device for preparing 5N pure sulfur dioxide provided by the utility model comprises a refrigerator 19 connected to the vaporizer 2, the liquefaction collection tank 5, and the condenser 21. In the utility model, the high-temperature cooling water generated by the operation of the refrigerator 19 is used to heat the vaporizer 2 through a pipeline to realize the reuse of waste heat.

[0035] In the utility model, the device for preparing 5N purity sulfur dioxide preferably further includes a recovery tank 10 connected to the top of the distillation tower 6.

[0036] In the present utility model, the device for preparing 5N purity sulfur dioxide preferably further comprises a tail gas treatment tower 11 connected to the top and bottom of the distillation tower 6 and the adsorption system 3 through pipelines;

[0037] Preferably, it also includes an inert gas storage tank 15 whose outlet is connected to the inlet of the vaporizer 2;

[0038] The connecting pipeline between the adsorption system 3 and the tail gas treatment tower 11 preferably further includes a vacuum pump 20 .

[0039] In the present invention, the connecting pipe between the vaporizer 2 and the inert gas storage tank 15 is preferably provided with an automatic pneumatic valve. In the present invention, the connecting pipe between the adsorption system 3 and the tail gas treatment tower 11 is preferably provided with an automatic pneumatic valve; the connecting pipe between the adsorption system 3 and the vacuum pump 20, and the connecting pipe between the vacuum pump 20 and the tail gas treatment tower 11 are preferably provided with automatic pneumatic valves. In the present invention, the connecting pipes between the top and bottom of the distillation tower 6 and the tail gas treatment tower 11 are preferably provided with automatic pneumatic valves.

[0040] In the present invention, the device for preparing 5N purity sulfur dioxide preferably further includes an automatic control system 16 and an emergency stop control system 17 which are connected to the device via electrical signals.

[0041] In the present invention, the automatic control system 16 is a DCS or PLC automatic control system.

[0042] The device is equipped with a remote automatic control system 16, which can adjust the process parameters and remotely start and stop the equipment through the remote central control room. The device is equipped with an emergency stop system 17, which can be safely stopped with one button in an emergency, meeting the requirements for safe and stable production and preparation of hazardous chemicals.

[0043] The utility model also provides a method for preparing 5N purity sulfur dioxide using the above-mentioned device, comprising the following steps:

[0044] The low-purity sulfur dioxide raw material is sequentially vaporized by a vaporizer, adsorbed by an adsorber, filtered by a precision filter, liquefied by a liquefaction collection tank, and rectified by a distillation tower to obtain a distillation product; the content of sulfur dioxide in the low-purity sulfur dioxide raw material is 80-99wt%;

[0045] The distillation product is detected in real time by an online analytical instrument, and after the product meets the standards, it is discharged to a collection system 7.

[0046] In the present invention, the vaporization temperature is 10-100°C, more preferably 40°C; the pressure in the vaporizer is preferably 0.2-1.0MPa, more preferably 0.6MPa, and the vaporization rate is preferably 50Kg / h.

[0047] In the utility model, the inflow rate of the gas to be adsorbed in the adsorption system is 50 Kg / h; the pressure of the adsorber is preferably 0.1-1.0 MPa, more preferably 0.6 MPa.

[0048] In the present invention, the liquefaction temperature is preferably -10 to -30°C, more preferably -20°C.

[0049] In the present invention, the distillation temperature is preferably 10-55° C., more preferably 25-40° C.; the distillation pressure is preferably 0.2-0.8 MPa, more preferably 0.3-0.5 MPa.

[0050] In order to further illustrate the present invention, the scheme of the present invention is described in detail below in conjunction with embodiments, but they should not be understood as limiting the protection scope of the present invention.

[0051] Example 1

[0052] A device for preparing 5N purity sulfur dioxide, see Figure 1 , including a sulfur dioxide raw material tank 1, a vaporizer 2, an adsorption system 3 (including two adsorbers connected in series), a filtration system 4 (two precision filters connected in series, the precision of the precision filter is 0.01μm), a liquefaction collection tank 5, a distillation tower 6 and a collection system 7 (a product tank 8, a filling pump 9 and a steel cylinder 14 connected in sequence); a condenser 21 is arranged on the top of the distillation tower 6, and a heating circulator 18 is arranged on the bottom; an online analytical instrument is arranged on the top of the distillation tower 6, including a helium ionization gas chromatograph 12 and an electrolytic moisture meter 13.

[0053] A refrigerator 19 connected to the vaporizer 2, the liquefied collection tank 5, and the condenser 21;

[0054] A recovery tank 10 connected to the top of the distillation tower 6;

[0055] A tail gas treatment tower 11 connected to the top and bottom of the distillation tower 6 and the adsorption system 3;

[0056] An inert gas storage tank 15 whose outlet is connected to the inlet of the vaporizer 2;

[0057] A vacuum pump 20 connected to the adsorption system 3 and the tail gas treatment tower 11;

[0058] A DCS automatic control system 16 and a SIS emergency stop control system 17 are connected to the device via electrical signals.

[0059] The preparation method of 5N purity sulfur dioxide is as follows:

[0060] The low-purity liquid sulfur dioxide raw material enters the vaporizer from the raw material tank 1 and is vaporized under the conditions of 40°C, vaporizer pressure 0.6MPa, and vaporization rate 50Kg / h. The heat required for vaporization comes from the high-temperature liquefied water generated by the operation of the refrigerator 19 during the condensation of the condenser and the liquefaction of the liquefied collection tank.

[0061] The vaporized gas enters the adsorption system for adsorption (adsorption purification flow rate 50Kg / h, adsorber pressure 0.6MPa), is filtered through a precision filter, and then liquefied through a liquefaction collection tank 5 (liquefaction temperature is -10°C), and finally enters a distillation tower 6 for distillation (distillation tower operating pressure 0.3MPa, distillation temperature 40°C).

[0062] After distillation, light component impurities (nitrogen, oxygen, argon, carbon dioxide, carbon monoxide, hydrogen, methane, ethane, propane) are discharged from the top of the tower through distillation to the recovery tank 10 for collection; the target product that has passed the inspection of the online analytical instrument is collected in the product tank 8 and then filled into the cylinder 14 through the filling pump 9; the sulfur dioxide-containing waste gas generated during the operation can be discharged through the bottom pipeline to the tail gas treatment tower 11 for absorption treatment.

[0063] The product obtained in Example 1 was detected by helium ionization gas chromatograph and electrolytic moisture meter:

[0064] Impurity content: water, 0.35ppm; nitrogen, 1.4ppm; oxygen, 0.7ppm; carbon dioxide, 0.5ppm; carbon monoxide, carbonyl sulfide, carbon disulfide, hydrogen sulfide, all not detected; hydrocarbons (C1~C4), not detected; sulfur dioxide>99.9995wt%.

[0065] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A device for preparing 5N purity sulfur dioxide, characterized in that: The system comprises a raw material tank (1), a vaporizer (2), an adsorption system (3), a filtration system (4), a liquefaction collection tank (5), a distillation tower (6) and a collection system (7) which are connected in sequence; a condenser (21) is arranged at the top of the distillation tower (6), and a heating circulator (18) is arranged at the bottom; and an online analysis instrument is arranged at the top of the distillation tower (6); a refrigerator (19) connected to the vaporizer (2), the liquefied gas collection tank (5), and the condenser (21); The adsorption system (3) comprises n adsorbers; n≥1, when n=1, the adsorbers comprise multiple layers of adsorbents filled in layers; the types of adsorbents in each layer are different; The filtering system (4) comprises m precision filters connected in series; m≥1.

2. The device according to claim 1, characterized in that The collection system (7) comprises a product tank (8), a filling pump (9) and a steel cylinder (14) which are connected in sequence.

3. The device according to claim 1, characterized in that It also includes a recovery tank (10) connected to the top of the distillation tower (6).

4. The device according to any one of claims 1 to 3, characterized in that: It also includes a tail gas treatment tower (11) connected to the top and bottom of the distillation tower (6) and the adsorption system (3) through pipelines; An inert gas storage tank (15) whose outlet is connected to the inlet of the vaporizer (2); An automatic control system (16) and an emergency stop control system (17) communicated with the device via electrical signals; The connecting pipeline between the adsorption system (3) and the tail gas treatment tower (11) also includes a vacuum pump (20).

5. The device according to claim 1 or 2, characterized in that: The online analytical instrument comprises a helium ionization gas chromatograph (12) and an electrolytic moisture analyzer (13).

6. The device according to claim 1, characterized in that The filtration accuracy of the precision filter is 0.003-10 μm.

7. The device according to claim 1, characterized in that The adsorbent includes one or more of activated carbon, molecular sieve, silica gel, alumina and high molecular porous polymer.

Images