Venturi scrubber

Abstract

The utility model relates to washing equipment in the field of chemical industry, in particular to a venturi scrubber which comprises a shell, the shell is composed of a metal outer shell and a non-metal inner shell with a venturi structure, the metal outer shell and the non-metal inner shell are in clearance fit, a cold fluid outlet is formed in the upper section of the metal outer shell, and a cold fluid outlet is formed in the lower section of the metal outer shell. A cold fluid inlet is formed in the lower section, and a flexible expansion section is arranged between the end outer flange of the metal outer shell and the end inner flange of the non-metal inner shell. The high-efficiency washing and absorbing device is simple in structure, safe, reliable, good in sealing performance, capable of adapting to high-corrosion, strong-permeation and negative-pressure working conditions and capable of efficiently washing and absorbing large-flow gas.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of chemical washing equipment, specifically a Venturi scrubber. BACKGROUND

[0002] In the process of preparing hydrogen fluoride by fluorosilicic acid method, the generated fluorine-containing gas components are complex, including hydrofluoric acid (HF), silicon tetrafluoride (SiF4), silicon dioxide (SiO2) and the like. These gases have low pH value, strong corrosiveness and high permeability. In particular, in a humid and high-temperature environment, the corrosion ability of hydrofluoric acid (HF) is particularly prominent. At the same time, the silicon dioxide (SiO2) in the medium produces strong abrasion to the equipment under high flow rate. CN201776053U discloses a graphite Venturi scrubber, which includes a gas inlet end at the top of the Venturi scrubber and a material outlet end at the bottom of the Venturi scrubber. The inner part adopts a steel lining graphite structure, and the entire inside is graphite, and the outside is wrapped with steel. It can be applied to high-temperature flue gas industry, and is more suitable for high-temperature and strong corrosion industry. The above structure has the following problems: 1) Although the steel lining graphite structure can improve the corrosion resistance, there is still a problem of strong permeation under negative pressure conditions, and the damage to the Venturi throat is not easy to detect. 2) When the graphite lining is abraded or damaged, it is not easy to replace. 3) Due to the difference in expansion coefficient between metal and non-metal, the flange end sealing is not good. How to design a Venturi scrubber that can not only adapt to high corrosion, strong permeation and negative pressure conditions, but also efficiently wash and absorb large flow gas, while ensuring safety, reliability, good sealing, economy and durability, has become a technical problem to be solved. SUMMARY

[0003] The utility model aims at solving the above technical problem, and provides a Venturi scrubber which has simple structure, is safe and reliable, has good sealing property, can adapt to high corrosion, strong permeation and negative pressure conditions, and can efficiently wash and absorb large flow gas.

[0004] The technical scheme comprises a shell composed of a metal shell and a non-metal inner shell with a Venturi structure. The metal shell and the non-metal inner shell are gap-fitted. The upper section of the metal shell is provided with a cold fluid outlet, and the lower section is provided with a cold fluid inlet. A plurality of flexible expansion sections are arranged between the outer flange of the end of the metal shell and the inner flange of the end of the non-metal inner shell.

[0005] The inclined angle α of the inlet section of the Venturi structure is 3-15°.

[0006] The inclined angle β of the outlet section of the Venturi structure is 2-10°.

[0007] A flow guide ring is arranged in the gap between the metal shell and the non-metal inner shell.

[0008] The flow guide ring is a spiral flow guide ring.

[0009] The center of the Venturi structure is provided with a spraying assembly.

[0010] The flexible expansion section is a spring structure flexible expansion section.

[0011] The spring structure flexible expansion section includes a limiting shell with an open lower end, a spring located in the limiting shell, a lower end of the spring abutting against an end inner flange of the non-metal inner shell through a base, and connecting one end of a pull rod, and the other end of the pull rod is connected with an end outer flange of the metal inner shell through the end inner flange of the non-metal inner shell.

[0012] The other end of the pull rod is fixedly connected with the end outer flange of the metal inner shell through a nut.

[0013] Beneficial effects:

[0014] 1) The shell is composed of a metal shell and a non-metal inner shell with a Venturi structure, the metal shell forms a closed shell, and the material is selected as a steel shell lined with plastic / gel to resist corrosion and erosion of strong penetrating media; the non-metal inner shell with a Venturi structure can be specifically selected as molded or injection molded plastic PTFE, machined / molded / injection molded graphite, or molded / injection molded silicon carbide to adapt to high corrosion environments. The gap fit between the two facilitates installation and removal for replacement. Preferably, the inclined angle α of the inlet section of the Venturi is 3-15°, and the inclined angle β of the outlet section is 2-10° to optimize gas flow and washing effect.

[0015] 2) The upper section of the metal shell is provided with a cold fluid outlet, and the lower section is provided with a cold fluid inlet. On the one hand, it can be used to suck the gas in the gap for detecting the gas components to monitor the damage of the Venturi throat; on the other hand, cold fluid can also be introduced into the bottom cold fluid inlet to form a positive pressure, reduce the penetration of the medium into the interlayer, protect and cool the cylinder wall, reduce the influence of high-temperature medium on the non-metal shell, so that the steel shell can use lower-cost metal materials, and reduce investment cost.

[0016] 3) The gap between the metal shell and the non-metal inner shell is provided with a flow guide ring, which can guide the flow of cold fluid to improve the cold heat exchange efficiency, and also can be used as an internal support to fix the non-metal inner shell.

[0017] 4) The flexible expansion section is provided to solve the thermal expansion coordination problem of the non-metal inner shell and the metal shell under high-temperature working conditions. Preferably, the flexible expansion section is a spring structure, the pressure of the spring can be self-adaptively adjusted by the nut at the lower end of the pull rod according to the thermal expansion amount, so as to ensure that the end inner flange of the non-metal inner shell is tightly pressed against the upper end of the non-metal inner shell, and the medium entering the gap is reduced.

[0018] 5)The utility model discloses simple structure, reliable durable, easy maintenance and overhaul, low in cost, can effectively respond to the strong corrosion and high permeability of HF, good sealing performance, ensure that the equipment is under the long-term stable operation of high temperature, negative pressure and other severe conditions. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is the structure schematic diagram of the utility model.

[0020] Figure 2 It is the partial enlarged view of flexible expansion section.

[0021] Wherein, 1-metal shell, 2-nonmetal inner shell, 3-cold fluid outlet, 4-spraying assembly, 5-end inner flange, 6-flexible expansion section, 6.1-spring, 6.2-pull rod, 6.3-base, 6.4-nut, 6.5-limiting shell, 7-end outer flange, 8-flow guide ring, 9-cold fluid inlet. DETAILED DESCRIPTION

[0022] The utility model will be further explained in connection with the drawings:

[0023] The utility model discloses a shell, the shell is composed of metal shell 1 and the nonmetal inner shell 2 with venturi structure, preferably, the venturi structure top center is equipped with spraying assembly 4, the venturi structure entrance section skew angle α is equipped with 3~15 °, and the venturi structure outlet section skew angle β is equipped with 2~10 °, adopts the above-mentioned angle skew angle and can optimize local gas flow, improves washing effect.The metal shell 1 and nonmetal inner shell 2 adopt gap fit, and the gap of metal shell 1 and nonmetal inner shell 3 is equipped with flow guide ring 8, preferably spiral flow guide ring.

[0024] The upper section of the metal shell 2 is provided with a cold fluid outlet 3, and the lower section is provided with a cold fluid inlet 9. A plurality of flexible expansion sections 6 are arranged between the end outer flange 7 of the metal shell 1 and the end inner flange 5 of the nonmetal inner shell 2. On the one hand, the gas in the gap can be sucked through the cold fluid outlet 3 for detection to monitor the damage of the venturi throat (such as leakage). On the other hand, cold fluid can be introduced through the cold fluid inlet 9 and then flow out through the cold fluid outlet 3, forming a positive pressure in the gap, reducing the penetration of the medium into the interlayer, protecting and cooling the shell, reducing the influence of high-temperature medium on the metal shell 1 and the nonmetal inner shell 3, and thus a lower-grade material can be used to manufacture the metal shell 1, reducing the cost.

[0025] As another example, the flexible expansion section 6 is a spring structure flexible expansion section, including a lower end open limiting shell 6.5 (the limiting shell 6.5 is fixed on the external support), a spring 6.1 located in the limiting shell 6.5, the lower end of the spring 6.1 abuts against the end inner flange 5 of the non-metal inner shell 2 through the base 6.3, and is connected to one end of the pull rod 6.2, the other end of the pull rod 6.2 is fixedly connected with the end outer flange 7 of the metal inner shell 1 through the nut 4 by penetrating the end inner flange 5 of the non-metal inner shell 2. The nut 4 is tightened to control the pre-tightening force of the spring 6.1, and the spring 6.1 is adaptively adjusted according to the thermal expansion amount to ensure that the bottom surface of the end inner flange 5 is tightly pressed against the upper end of the non-metal inner shell 2, thereby ensuring the sealing effect and reducing the possibility of medium entering the gap.

Claims

1. A venturi scrubber comprising a housing composed of a metal outer shell and a non-metal inner shell having a venturi structure, characterized in that, The metal shell and the nonmetal inner shell adopt clearance fit, the upper section of the metal shell is provided with a cold fluid outlet, the lower section is provided with a cold fluid inlet, and a plurality of flexible expansion sections are arranged between the end outer flange of the metal shell and the end inner flange of the nonmetal inner shell.

2. The venturi scrubber of claim 1, wherein The inclined angle α of the inlet section of the Venturi structure is 3-15°.

3. The venturi scrubber of claim 1 wherein, The inclined angle β of the outlet section of the Venturi structure is 2-10°.

4. The venturi scrubber of claim 1 wherein, A flow guide ring is arranged in the clearance between the metal shell and the nonmetal inner shell.

5. The venturi scrubber of claim 4, wherein, The flow guide ring is a spiral flow guide ring.

6. The venturi scrubber of claim 4 wherein, A spraying assembly is arranged at the upper center of the Venturi structure.

7. A venturi scrubber as claimed in any one of claims 1 to 6 wherein, The flexible expansion section is a spring structure flexible expansion section.

8. The venturi scrubber of claim 7, wherein, The spring structure flexible expansion section comprises a limiting shell with an open lower end and a spring arranged in the limiting shell, the lower end of the spring is abutted against the end inner flange of the nonmetal inner shell through a base and is connected to one end of a pull rod, the other end of the pull rod is connected to the end outer flange of the metal inner shell through the end inner flange of the nonmetal inner shell.

9. The venturi scrubber of claim 8, wherein, The other end of the pull rod is fixedly connected to the end outer flange of the metal inner shell through a nut.

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