A tail gas treatment system for the process of removing metal cations from wet phosphoric acid

Abstract

The utility model discloses a tail gas treatment system for a wet phosphoric acid demetallization cation process, belonging to the technical field of phosphate compound fertilizer production. It comprises a demetallization tank, a hydraulic ejector, a liquid seal tank and a defoaming washing tower, an exhaust pipe a is arranged on the top of the demetallization tank, the exhaust pipe a is communicated with the air inlet of the hydraulic ejector, the hydraulic ejector is communicated and arranged on the liquid seal tank, a water outlet pipe is arranged at the bottom of the liquid seal tank and is communicated with the water inlet of the hydraulic ejector, an exhaust pipe b is arranged on the top of the liquid seal tank, and the outlet end of the exhaust pipe b is located at the lower side of the inside of the defoaming washing tower. The utility model has high absorption efficiency, small equipment volume, small floor space, and is easy to promote and use.

Description

Technical Field

[0001] The utility model relates to the technical field of tail gas treatment, in particular to a tail gas treatment system used in a wet phosphoric acid metal cation removal process. Background Art

[0002] At present, the tail gas from the phosphoric acid pretreatment process for removing metal cations mainly contains H 2 S, HF and other toxic and harmful gases. The existing tail gas treatment mainly uses induced draft fans to remove the H-containing gases produced by the demetallization tank. 2 The tail gas containing S, HF, etc. is introduced into the first-level packing washing tower and spray-washed with low-concentration NaOH, and then treated in the first-level washing and defoaming exhaust tower. The disadvantage of the above tail gas treatment is that the fan and the conveying pipeline containing high-concentration harmful tail gas are conveyed under positive pressure, and the gas is highly corrosive and easy to leak. In addition, the spray washing is not closed, the washing rate is low, and the tail gas contains a certain amount of H 2 S gas is discharged, which has an impact on the environment. Utility Model Content

[0003] The purpose of the utility model is to provide a leak-proof closed micro-negative pressure washing tail gas treatment system for the metal cation removal process of wet phosphoric acid, which adopts a combination of a primary hydraulic jet closed washing system and a secondary defoaming spray washing system to achieve tail gas transportation and washing in a closed, micro-negative pressure state. Thus, the problems raised in the above background technology are solved.

[0004] The technical solution adopted by the utility model is as follows:

[0005] A tail gas treatment system for a wet phosphoric acid metal cation removal process comprises a demetallization tank 1, a hydraulic ejector 2, a liquid seal tank 3 and a defoaming washing tower 4, wherein an exhaust pipe a6 is arranged on the top of the demetallization tank 1, and the exhaust pipe a6 is communicated with the air inlet of the hydraulic ejector 2, the hydraulic ejector 2 is communicated and arranged on the liquid seal tank 3, a water outlet pipe 8 is arranged at the bottom of the liquid seal tank 3 and is communicated with the water inlet of the hydraulic ejector 2, an exhaust pipe b7 is arranged on the top of the liquid seal tank 3, and the outlet end of the exhaust pipe b7 is located at the lower side of the inside of the defoaming washing tower 4.

[0006] The water outlet pipe 8 is provided with a circulation pump.

[0007] A guide 5 is provided on the outlet end of the exhaust pipe b7.

[0008] A stirring paddle is arranged in the liquid sealing tank 3 , and a driving motor of the stirring paddle is arranged on the top cover of the liquid sealing tank 3 .

[0009] A stirring paddle is arranged in the demetallization tank 1, a drain pipe is arranged at the bottom of the demetallization tank 1, and a water pump is arranged on the drain pipe.

[0010] In summary, due to the adoption of the above technical solution, the beneficial effects of the utility model are:

[0011] 1. The hydraulic ejector and liquid sealing groove provided in the utility model adopt a vacuum absorption method, which has a low risk of leakage, effectively reduces the emission of exhaust gas, protects the atmospheric environment, and is safe and environmentally friendly.

[0012] 2. The defoaming washing tower provided in the utility model utilizes the principle of positive collision defoaming to make the washing and defoaming efficiency higher.

[0013] In summary, the utility model has high absorption efficiency, small equipment size, small footprint, and is easy to promote and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the utility model;

[0015] Figure 2 It is a structural schematic diagram of the hydraulic ejector of the utility model;

[0016] As shown in the figure: demetallization tank 1; hydraulic ejector 2; liquid seal tank 3; defoaming washing tower 4; guide 5; exhaust pipe a6; exhaust pipe b7; water outlet pipe 8; water inlet 201; air inlet 202; water nozzle 203. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Generally, the components of the embodiment of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Example

[0020] like Figure 1-2This embodiment provides an exhaust gas treatment system for a wet phosphoric acid demetallization cation process, comprising a demetallization tank 1, a hydraulic ejector 2, a liquid seal tank 3 and a defoaming washing tower 4, an exhaust pipe a6 is arranged on the top of the demetallization tank 1, and the exhaust pipe a6 is communicated with the air inlet of the hydraulic ejector 2, the hydraulic ejector 2 is communicated and arranged on the liquid seal tank 3, a water outlet pipe 8 is arranged at the bottom of the liquid seal tank 3 and is communicated with the water inlet of the hydraulic ejector 2, an exhaust pipe b7 is arranged on the top of the liquid seal tank 3, and the outlet end of the exhaust pipe b7 is located at the lower side of the inside of the defoaming washing tower 4. A circulating pump is arranged on the water outlet pipe 8.

[0021] The outlet end of the exhaust pipe b7 is provided with a guide 5. The guide is an "L"-shaped steering head, and its opening is in a trumpet shape.

[0022] A stirring paddle is arranged in the liquid sealing tank 3 , and a driving motor of the stirring paddle is arranged on the top cover of the liquid sealing tank 3 .

[0023] The demetallization tank 1 is provided with a stirring paddle, and the driving motor of the stirring paddle is provided on the top cover of the demetallization tank. A drainage pipe is provided at the bottom of the demetallization tank 1, and a water pump is provided on the drainage pipe. The demetallization tank is closed and a feed pipe is provided on it.

[0024] The use principle of the utility model is that H 2 The tail gas of S enters the hydraulic ejector under the suction formed by the hydraulic ejector and is washed by a large amount of washing liquid containing low concentration NaOH from the liquid seal tank; the highly soluble gas H 2 After S is absorbed, the system vacuum is further improved. A small amount of insoluble gas is carried into the liquid seal tank by the water flow and then overflows, then enters the exhaust pipe b7 through the guide 5 and enters the defoamer 4, and then directly collides with the liquid remaining at the bottom of the washing tower to defoam, and is discharged through the exhaust pipe after washing and defoaming.

Claims

1. A tail gas treatment system for a wet phosphoric acid metal cation removal process, comprising a metal removal tank (1), a hydraulic ejector (2), a liquid seal tank (3) and a defoaming scrubber (4), characterized in that: An exhaust pipe a (6) is arranged at the top of the demetallization tank (1), and the exhaust pipe a (6) is connected to the air inlet of the hydraulic ejector (2). The hydraulic ejector (2) is arranged on the liquid seal tank (3), and a water outlet pipe (8) is arranged at the bottom of the liquid seal tank (3) and is connected to the water inlet of the hydraulic ejector (2). An exhaust pipe b (7) is arranged at the top of the liquid seal tank (3), and the outlet end of the exhaust pipe b (7) is located at the lower side of the interior of the defoaming washing tower (4).

2. The tail gas treatment system for the metal cation removal process of wet phosphoric acid according to claim 1, characterized in that: The water outlet pipe (8) is provided with a circulation pump.

3. The tail gas treatment system for the metal cation removal process of wet phosphoric acid according to claim 1, characterized in that: A guide (5) is provided on the outlet end of the exhaust pipe b (7).

4. The tail gas treatment system for the metal cation removal process of wet phosphoric acid according to claim 1, characterized in that: A stirring paddle is arranged in the liquid sealing tank (3), and a driving motor of the stirring paddle is arranged on the top cover of the liquid sealing tank (3).

5. The tail gas treatment system for the metal cation removal process of wet phosphoric acid according to claim 1, characterized in that: A stirring paddle is arranged in the demetallization tank (1), a drainage pipe is arranged at the bottom of the demetallization tank (1), and a water pump is arranged on the drainage pipe.

Images