Silicon dioxide filtering system for preparing hydrogen fluoride from low-concentration fluosilicic acid

Abstract

The utility model discloses a silicon dioxide filtering system for preparing hydrogen fluoride from low-concentration fluosilicic acid, which comprises a feeding tank, a feeding pump is arranged at a discharge port of the feeding tank, a discharge port of the feeding pump is communicated with a buffer tank through silicon dioxide filtering modules which are connected in parallel, each silicon dioxide filtering module is provided with a backwashing module, and the backwashing module is communicated with the buffer tank. The feeding end of the backwashing module is connected with the buffer tank, the discharging end of the backwashing module is connected with the feeding tank, the silicon dioxide filtering modules can operate alternately, and when one filtering module operates, the other filtering module performs backwashing through the backwashing module, so that the filtering modules are prevented from being blocked after long-time operation; the continuous filtering operation and the filtering efficiency are ensured, and the service life of the device is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrogen fluoride production equipment, in particular to a silicon dioxide filtering system used for preparing hydrogen fluoride from low-concentration fluosilicic acid. Background Art

[0002] In the process of preparing hydrogen fluoride from low-concentration fluosilicic acid, the dilute fluosilicic acid is first converted into 30% medium-concentrated fluosilicic acid through a concentration process. Then, through a concentration process, the 30% medium-concentrated fluosilicic acid and silicon tetrafluoride gas undergo an exothermic reaction. During this process, the excess silicon tetrafluoride will continue to react with the water in the fluosilicic acid to finally produce fully reacted concentrated fluosilicic acid and silicon dioxide particles. Before the subsequent process, the silicon dioxide particles need to be separated through a filtration process. The common filtration process is to use a silicon dioxide filtration module including a filter.

[0003] The existing filtering process has the following problems:

[0004] 1. There is usually only one silica filter module, which may become clogged after long-term operation, affecting the filtering effect;

[0005] 2. The clogged silica filter module needs to be shut down for cleaning. At this time, the production process needs to wait until the cleaning is completed before it can be started. It cannot run continuously and is not convenient for cleaning. Utility Model Content

[0006] The utility model provides a silica filtration system for preparing hydrogen fluoride from low-concentration fluosilicic acid, aiming to solve the problems in the above-mentioned hydrogen fluoride preparation process of silica particle filtration being clogged, affecting the filtration effect, and the device being unable to operate continuously and being inconvenient to clean.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A silica filtration system for preparing hydrogen fluoride from low-concentration fluorosilicic acid includes a feed trough, a feed pump is provided at the discharge port of the feed trough, and the discharge port of the feed pump is connected to a buffer tank through parallel silica filtration modules. Each silica filtration module is provided with a backwash module, the feed end of the backwash module is connected to the buffer tank, and the discharge end of the backwash module is connected to the feed trough.

[0009] Preferably, the silica filtration modules all include a closed filter, the feed end of the filter is connected in parallel with the discharge port of the feed pump through a feed pipe, and the discharge end of the filter is connected in parallel with the buffer tank through a discharge pipe.

[0010] As a more preferred embodiment, the filtering direction of the filter is opposite to the backwashing direction, the filtering direction is from bottom to top in the filter, and the backwashing direction is from top to bottom in the filter.

[0011] Furthermore, a feed end is provided at the bottom of one side of the filter, a discharge end is provided at the top of the filter on the side opposite to the feed end, a backwash discharge end is provided at the bottom of the filter on the side opposite to the feed end, and a backwash feed end is provided at the top of the filter on the side opposite to the discharge end.

[0012] Furthermore, the backwash modules include a backwash inlet pipe and a backwash outlet pipe. The backwash feed end of the filter is connected to the buffer tank through the backwash inlet pipe, and a backwash pump is provided on the backwash inlet pipe. The backwash outlet end of the filter is connected to the feed tank through the backwash outlet pipe.

[0013] Specifically, a feed valve is provided before the feed inlet of the backwash pump, and a feed valve is provided before the feed inlet of the feed pump.

[0014] More specifically, a feed valve is provided on the feed pipe near the feed end and on the backwash liquid inlet pipe near the backwash feed end.

[0015] In detail, a discharge valve is provided on the discharge pipe near the discharge end and on the backwash liquid discharge pipe near the backwash discharge end.

[0016] Beneficial effects of the utility model:

[0017] The utility model realizes alternating operation of the filter modules by connecting silica filter modules in parallel. When one filter module is closed for cleaning due to blockage, the other filter module can be opened to ensure continuous operation of production and filtering effect.

[0018] Secondly, the system can perform backwashing operations through the backwash module on each silica filter module. When one of the filter modules is closed for cleaning due to blockage, the backwash module of the closed filter module can be opened, and the solvent filtered out of the buffer tank can be directly used as a detergent. The cleaned mixed solution is re-introduced into the feed tank for re-filtration without adding additional backwashing reagents, thereby ensuring the purity of the filter machine and not affecting the quality of the solvent in the buffer tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the process connection of the utility model;

[0020] In the figure: 1. Feed trough; 2. Feed pump;

[0021] 3. Silica filtration module; 301. Feed pipe; 302. Filter; 303. Discharge pipe;

[0022] 4. Buffer tank;

[0023] 5. Backwash module; 501. Backwash liquid inlet pipe; 502. Backwash pump; 503. Backwash liquid outlet pipe;

[0024] 6. Inlet valve; 7. Outlet valve. DETAILED DESCRIPTION

[0025] As follows, embodiments are further described with reference to the accompanying drawings.

[0026] like Figure 1 As shown, as a preferred embodiment 1, a silica filtration system for preparing hydrogen fluoride from low-concentration hydrosilicic acid includes a feed trough 1, a feed pump 2 is provided at the discharge port of the feed trough 1, and the discharge port of the feed pump 2 is connected to a buffer tank 4 through a parallel silica filtration module 3, each of the silica filtration modules 3 is provided with a backwash module 5, the feed end of the backwash module 5 is connected to the buffer tank 4, and the discharge end of the backwash module 5 is connected to the feed trough 1.

[0027] The parallel silica filter modules 3 facilitate alternating operation. When one filter module is running, the other filter module can be shut down and backwashed directly using the filter solvent in the buffer tank 4 through the backwash module 5, without introducing impurities, ensuring the backwash effect and the filtration quality.

[0028] The silica filtration modules 3 each include a sealed filter 302 , the feed end of the filter 302 being connected in parallel to the discharge port of the feed pump 2 via a feed pipe 301 , and the discharge end of the filter 302 being connected in parallel to the buffer tank 4 via a discharge pipe 303 , ensuring smooth filtration.

[0029] The filter 302 may be an existing filter with a backwash interface.

[0030] The filtering direction of the filter 302 is opposite to the backwashing direction, that is, the filtering direction is from bottom to top in the filter 302, and the backwashing direction is from top to bottom in the filter 302, thereby ensuring the filtering and backwashing effects.

[0031] The filter 302 has a feed port at the bottom of one side, a discharge port at the top of the filter 302 on the side opposite to the feed port, a backwash discharge port at the bottom of the filter 302 on the side opposite to the feed port, and a backwash feed port at the top of the filter 302 on the side opposite to the discharge port, to facilitate pipe connection.

[0032] The backwash modules 5 each include a backwash inlet pipe 501 and a backwash outlet pipe 503. The backwash feed end of the filter 302 is connected to the buffer tank 4 via the backwash inlet pipe 501. A backwash pump 502 is provided on the backwash inlet pipe 501. The backwash outlet end of the filter 302 is connected to the feed tank 1 via the backwash outlet pipe 503 to ensure smooth backwashing.

[0033] A feed valve 6 is provided before the feed inlet of the backwash pump 502, and a feed valve 6 is provided before the feed inlet of the feed pump 2. This facilitates the control process.

[0034] The feed pipe 301 is provided with a feed valve 6 near the feed end and the backwash liquid inlet pipe 501 is provided with a feed valve 6 near the backwash feed end to facilitate the control process.

[0035] The discharge pipe 303 is provided with a discharge valve 7 near the discharge end and the backwash liquid discharge pipe 503 is provided with a discharge valve 7 near the backwash discharge end to facilitate the control process.

[0036] The bottom of the filter 302 is provided with a solid discharge end, and the solid discharge end is provided with a discharge valve 7 to facilitate the control process.

[0037] As a preferred embodiment 2, the method of using this system is as follows:

[0038] During the initial startup operation, the feed valve 6 before the feed port of the feed pump 2 is opened, and the feed valve 6 on the feed pipe 301 and the discharge valve 7 on the discharge pipe 303 of one of the silica filter modules 3 are opened. The other valves remain closed, so that the mixed material is guided from the feed tank 1 by the feed pump 2, and then passes through the filter 302 for solid-liquid separation, and the liquid is collected by the buffer tank 4;

[0039] When the running silica filter module 3 is clogged, the feed valve 6 on the feed pipe 301 and the discharge valve 7 on the discharge pipe 303 of the running silica filter module 3 are closed, and the feed valve 6 on the feed pipe 301 and the discharge valve 7 on the discharge pipe 303 of another silica filter module 3 are opened to complete the switching, and the backwash module 5 of the silica filter module 3 that is in the closed state after the switching is turned on, and the feed valve 6 on the backwash inlet pipe 501 and the discharge valve 7 on the backwash outlet pipe 503 of the backwash module 5 are opened. The backwashing power is provided by the backwashing pump 502 to backwash the closed filter 302. After backwashing for a period of time, the backwashing module 5 is closed to allow the silica filter module 3 to wait for the next switching;

[0040] When the filtering conditions of the two silica filter modules 3 cannot be improved by backwashing, the entire system is shut down for inspection and maintenance.

[0041] As a preferred embodiment 3, a flow monitoring mechanism may be provided on the discharge pipe 303, such as a flow meter in the prior art, to determine whether there is blockage.

[0042] The working principle of this utility model:

[0043] The utility model realizes alternating operation of the filter modules by connecting the silica filter modules 3 in parallel. When one filter module is closed for cleaning due to blockage, the other filter module can be opened to ensure continuous operation of production and filtering effect.

[0044] Secondly, the system can perform backwashing operations through the backwash module 5 on each silica filter module 3. When one of the filter modules is closed for cleaning due to blockage, the backwash module 5 of the closed filter module can be opened, and the solvent filtered out of the buffer tank 4 can be directly used as a detergent. The cleaned mixed solution is re-introduced into the feed tank 1 for re-filtration without adding additional backwashing reagents, thereby ensuring the purity of the filter 302 and not affecting the quality of the solvent in the buffer tank 4.

Claims

1. A silica filtration system for preparing hydrogen fluoride from low-concentration fluosilicic acid, comprising a feed tank (1), characterized in that: The discharge port of the feed trough (1) is provided with a feed pump (2), and the discharge port of the feed pump (2) is connected to the buffer tank (4) through the parallel silica filter modules (3), and each silica filter module (3) is provided with a backwash module (5), and the feed end of the backwash module (5) is connected to the buffer tank (4), and the discharge end of the backwash module (5) is connected to the feed trough (1).

2. The silicon dioxide filtration system for preparing hydrogen fluoride from low-concentration hydrosilicic acid according to claim 1, characterized in that: The silica filter modules (3) all include a sealed filter (302), the feed end of the filter (302) is connected in parallel to the discharge port of the feed pump (2) through a feed pipe (301), and the discharge end of the filter (302) is connected in parallel to the buffer tank (4) through a discharge pipe (303).

3. The silicon dioxide filtration system for preparing hydrogen fluoride from low-concentration hydrosilicic acid according to claim 2, characterized in that: The filtering direction of the filter (302) is opposite to the backwashing direction. The filtering direction is from bottom to top in the filter (302), and the backwashing direction is from top to bottom in the filter (302).

4. The silicon dioxide filtration system for preparing hydrogen fluoride from low-concentration hydrosilicic acid according to claim 3, characterized in that: A feed end is provided at the bottom of one side of the filter (302), a discharge end is provided at the top of the filter (302) on the side opposite to the feed end, a backwash discharge end is provided at the bottom of the filter (302) on the side opposite to the feed end, and a backwash feed end is provided at the top of the filter (302) on the side opposite to the discharge end.

5. The silicon dioxide filtration system for preparing hydrogen fluoride from low-concentration hydrosilicic acid according to claim 4, characterized in that: The backwash modules (5) each comprise a backwash inlet pipe (501) and a backwash outlet pipe (503); the backwash inlet end of the filter (302) is connected to the buffer tank (4) via the backwash inlet pipe (501); a backwash pump (502) is provided on the backwash inlet pipe (501); and the backwash outlet end of the filter (302) is connected to the feed tank (1) via the backwash outlet pipe (503).

6. The silicon dioxide filtration system for preparing hydrogen fluoride from low-concentration hydrosilicic acid according to claim 5, characterized in that: A feed valve (6) is provided before the feed inlet of the backwash pump (502), and a feed valve (6) is provided before the feed inlet of the feed pump (2).

7. The silicon dioxide filtration system for preparing hydrogen fluoride from low-concentration hydrosilicic acid according to claim 6, characterized in that: The feed pipe (301) is provided with a feed valve (6) near the feed end and the backwash liquid inlet pipe (501) is provided with a feed valve (6) near the backwash feed end.

8. The silicon dioxide filtration system for preparing hydrogen fluoride from low-concentration hydrosilicic acid according to claim 7, characterized in that: The discharge pipe (303) is provided with a discharge valve (7) near the discharge end and the backwash liquid discharge pipe (503) is provided with a discharge valve (7) near the backwash discharge end.

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