Phosphoric acid production device with low hydrogen sulfide environment concentration

Abstract

The utility model relates to a phosphoric acid production device with low hydrogen sulfide environmental concentration, which comprises a reactor, a precipitation pot, an air stripping tower, an arsenic removal filter, a filler degassing tower and a finished product filter which are sequentially connected, a bottom outlet of the precipitation pot is connected with a liquid inlet of the air stripping tower through a first delivery pump, and a plurality of layers of rotational flow components are arranged in the degassing tower from bottom to top. Each rotational flow assembly is provided with a plurality of rotational flow blades, an air inlet and a liquid outlet are respectively formed in the side wall of the bottom of the air stripping tower, and the air inlet and the liquid outlet are both formed below the rotational flow assembly at the bottommost layer. According to the utility model, the stripping tower is arranged in front of the arsenic removal filter, so that the stripping rate of hydrogen sulfide reaches up to 80%, the pre-degassing effect is obvious, the environmental concentration of hydrogen sulfide in a production field is greatly reduced, the alarm frequency of hydrogen sulfide is reduced, and the working efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of phosphoric acid purification, in particular to a phosphoric acid production device with low hydrogen sulfide environmental concentration. Background Art

[0002] Phosphoric acid is produced primarily by wet and thermal methods. Both methods produce phosphoric acid containing impurities, necessitating their removal. The current phosphoric acid purification process utilizes an excess pressurized hydrogen sulfide reaction, primarily completed in a reactor and a settling pot. The reacted phosphoric acid and unreacted excess hydrogen sulfide are then passed through an arsenic removal filter to remove arsenic residue. A packed degassing tower is then used to remove the remaining hydrogen sulfide gas from the phosphoric acid. Throughout the purification process, hydrogen sulfide is constantly present in excess. The clear liquid after slag-liquid separation in the arsenic removal filter is not hermetically sealed from the environment, resulting in small amounts of hydrogen sulfide spillage and frequent on-site hydrogen sulfide alarms. Utility Model Content

[0003] The purpose of the utility model is to overcome the above-mentioned shortcomings and provide a phosphoric acid production device with low hydrogen sulfide environmental concentration, which reduces hydrogen sulfide overflow during the arsenic removal reaction of phosphoric acid by a pre-degassing method.

[0004] The purpose of this utility model is achieved in this way:

[0005] A phosphoric acid production device for a low hydrogen sulfide concentration environment comprises a reactor, a precipitation pot, a stripping tower, an arsenic removal filter, a packing degassing tower, and a finished product filter, which are connected in sequence. The bottom outlet of the precipitation pot is connected to the liquid inlet of the stripping tower via a first delivery pump. The degassing tower is provided with multiple layers of cyclone components from bottom to top, each cyclone component being provided with multiple cyclone blades. An air inlet and a liquid outlet are respectively provided on the sidewalls of the bottom of the stripping tower, and the air inlet and the liquid outlet are both arranged below the bottom cyclone component.

[0006] Preferably, a plurality of swirl blades are evenly distributed outside the positioning ring at a certain inclination angle, and the fixing ring is fixed on the column.

[0007] Preferably, each swirl component is provided with a swirl blade.

[0008] Preferably, the outlet of the arsenic removal filter is connected to the upper inlet of the packed degassing tower through a second delivery pump, the lower outlet of the packed degassing tower is connected to the finished product filter, and the finished product filter is connected to the phosphoric acid finished product tank.

[0009] Preferably, a wire mesh demister is further provided in the stripping tower, and the wire mesh demister is arranged above the topmost cyclone component.

[0010] Preferably, the tops of the stripping tower and the packed degassing tower are both provided with gas outlets, and the gas outlets are connected to the tail gas processor.

[0011] Preferably, the stripping tower is provided with 1-2 liquid inlets, and the liquid inlets are arranged at the upper part of the stripping tower.

[0012] Preferably, when there is only one liquid inlet, the liquid inlet is arranged between the topmost cyclone component and the wire mesh demister.

[0013] The beneficial effects of the utility model are:

[0014] The utility model arranges a stripping tower in front of an arsenic removal filter to pre-degast excess hydrogen sulfide and reduce overflow of hydrogen sulfide during arsenic removal reaction of phosphoric acid; phosphoric acid containing hydrogen sulfide coming out of the bottom of a precipitation pot is pumped to the upper part of the stripping tower by a first delivery pump; a multi-layer cyclone component is installed in the stripping tower; liquid is sprayed from top to bottom and flows downward in a film shape on the surface of the cyclone blades; hot air is fed into the tower bottom and contacts the liquid film in countercurrent from bottom to top to complete the mass transfer process; in this process, the stripping rate of hydrogen sulfide on the liquid surface is generally ≥80%, the pre-degasping effect is significant, the concentration of hydrogen sulfide in the production site environment is greatly reduced, the number of hydrogen sulfide alarms is reduced, and work efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a structural schematic diagram of a phosphoric acid production device with low hydrogen sulfide concentration in the utility model.

[0016] Figure 2 Schematic diagram of the structure of the stripping tower.

[0017] Figure 3 A top view of the swirl component.

[0018] The structure comprises: a reactor 1; a settling pot 2; a stripping tower 3; a liquid inlet 3.1; an air inlet 3.2; a liquid outlet 3.3; an arsenic removal filter 4; a packing degassing tower 5; a finished product filter 6; a first delivery pump 7; a positioning ring 8; a swirl blade 9; a column 10; a second delivery pump 11; a phosphoric acid finished product tank 12; and a wire mesh demister 13. DETAILED DESCRIPTION

[0019] See also Figure 1-3The utility model relates to a phosphoric acid production device with low hydrogen sulfide concentration, comprising a reactor 1, a precipitation pot 2, a stripping tower 3, an arsenic removal filter 4, a packing degassing tower 5 and a finished product filter 6 connected in sequence. The bottom outlet of the precipitation pot 2 is connected to the liquid inlet 3.1 of the stripping tower 3 through a first delivery pump 7. The degassing tower 3 is provided with multiple layers of swirl components from bottom to top. Each swirl component includes a positioning ring 8 and multiple swirl blades 9. The multiple swirl blades 9 are evenly distributed outside the positioning ring 8 at a certain inclination angle. Each swirl component is provided with 2 4 swirl blades 9, the positioning ring 8 is fixed on the column 10, and the side walls of the bottom of the stripping tower 3 are respectively provided with an air inlet 3.2 and a liquid outlet 3.3, and the air inlet 3.2 and the liquid outlet 3.3 are both arranged below the bottom swirl component. The liquid outlet 3.3 of the stripping tower 3 is connected to the arsenic removal filter 4, and the outlet of the arsenic removal filter 4 is connected to the upper inlet of the packed degassing tower 5 through the second delivery pump 11. The lower outlet of the packed degassing tower 5 is connected to the finished product filter 6, and the finished product filter 6 is connected to the phosphoric acid finished product tank 12.

[0020] The stripping tower 3 is further provided with a wire mesh demister 13 , which is arranged above the topmost cyclone assembly.

[0021] The stripping tower 3 is provided with one to two liquid inlets 3.1, which are located at the upper portion of the stripping tower 3. When there is one liquid inlet 3.1, it is located between the topmost cyclone assembly and the wire mesh demister 13; when there are two liquid inlets 3.1, the additional liquid inlet is located between the topmost cyclone assembly and the second-top cyclone assembly.

[0022] The tops of the stripping tower 3 and the packed degassing tower 5 are both provided with gas outlets, and the gas outlets are connected to the tail gas processor.

[0023] Working principle:

[0024] The hydrogen sulfide-containing phosphoric acid exiting the bottom of the precipitation pot 2 is pumped to the upper portion of a stripping tower 3 by a first delivery pump 7. A multi-layer cyclone assembly is installed within the stripping tower 3. Liquid is sprayed downward from the top, flowing downward in a film-like manner on the surface of cyclone blades 9. Hot air is introduced from the bottom of the tower and countercurrently contacts the liquid film from bottom to top, completing the mass transfer process. During this process, the hydrogen sulfide stripping rate on the liquid surface is ≥80%. The pre-degassed phosphoric acid enters an arsenic removal filter 4 to remove arsenic residue, and is then degassed again in a packed degassing tower 5 to ensure that no hydrogen sulfide residue remains in the final product.

[0025] In addition to the above embodiments, the present invention also includes other implementation methods. Any technical solutions formed by equivalent transformation or equivalent replacement should fall within the scope of protection of the claims of the present invention.

Claims

1. A phosphoric acid production device with low hydrogen sulfide concentration, characterized in that: The invention comprises a reactor, a precipitation pot, a stripping tower, an arsenic removal filter, a packing degassing tower and a finished product filter connected in sequence. The bottom outlet of the precipitation pot is connected to the liquid inlet of the stripping tower through a first delivery pump. The degassing tower is provided with multiple layers of cyclone components from bottom to top. Each cyclone component is provided with multiple cyclone blades. The side walls of the bottom of the stripping tower are respectively provided with an air inlet and a liquid outlet. The air inlet and the liquid outlet are both arranged below the cyclone component on the bottom layer.

2. The phosphoric acid production device with low hydrogen sulfide concentration according to claim 1, characterized in that: A plurality of swirl blades are evenly distributed outside a positioning ring at a certain inclination angle, and the positioning ring is fixed on the column.

3. A phosphoric acid production device with low hydrogen sulfide concentration according to claim 1 or 2, characterized in that: Each swirl component is provided with a swirl blade.

4. The phosphoric acid production device with low hydrogen sulfide concentration according to claim 1, characterized in that: The outlet of the arsenic removal filter is connected to the upper inlet of the packed degassing tower through a second delivery pump, the lower outlet of the packed degassing tower is connected to the finished product filter, and the finished product filter is connected to the phosphoric acid finished product tank.

5. The phosphoric acid production device with low hydrogen sulfide concentration according to claim 1, characterized in that: A wire mesh demister is also provided in the stripping tower and is arranged above the topmost cyclone component.

6. The phosphoric acid production device with low hydrogen sulfide concentration according to claim 1, characterized in that: The tops of the stripping tower and the packing degassing tower are both provided with gas outlets, and the gas outlets are connected to the tail gas processor.

7. The phosphoric acid production device with low hydrogen sulfide concentration according to claim 1, characterized in that: The stripping tower is provided with 1-2 liquid inlets, which are arranged at the upper part of the stripping tower.

8. The phosphoric acid production device with low hydrogen sulfide concentration according to claim 7, characterized in that: When there is only one liquid inlet, the liquid inlet is arranged between the topmost cyclone component and the wire mesh demister.

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