CN210825429U - Fluorine absorption system in wet process phosphoric acid production - Google Patents

Abstract

The utility model discloses a fluorine absorption system in phosphoric acid production by wet process, fluorine absorption system includes venturi scrubber, first scrubbing tower, vapour and liquid separator tower, the second scrubbing tower in phosphoric acid production by wet process, venturi scrubber, first scrubbing tower and second scrubbing tower moisturizing all with moisturizing pipe-line connection, the venturi scrubber is given vent to anger and is connected with first scrubbing tower, the venturi scrubber is given vent to anger and is admitted air with first scrubbing tower and be connected, be provided with lower floor's shower and upper shower in the first scrubbing tower, first scrubbing tower top is given vent to anger and is connected with vapour and liquid separator tower, vapour and liquid separator tower is given vent to anger and is connected with the second scrubbing tower through the fan, be provided with the second shower in the second scrubbing tower. The utility model discloses can effectively reduce exhaust tail gas area liquid measure, satisfy the environmental protection requirement to, adopted the displacement water recycling mode, effectively improve fluorine absorption efficiency, simultaneously, establish the filter before the circulating pump import, prevent to receive hydrophone, shower and block up, prolong clearance period, reduce the maintenance cost.

Description

Fluorine absorption system in wet process phosphoric acid production

Technical Field

The utility model relates to the technical field of chemical process of wet-process phosphoric acid by a dihydrate method, in particular to a fluorine absorption system in the production of wet-process phosphoric acid.

Background

In the production process of wet-process phosphoric acid, the tail gas from a reaction tank and a digestion tank needs to be repeatedly washed and settled to ensure that the fluorine content of the tail gas meets the environmental protection standard and is discharged into the atmosphere. However, there are problems in that: (1) the tail gas discharged from the chimney carries liquid, and the tail gas has high humidity, so that the environment around the chimney is poor; (2) the replacement water is easy to generate silica gel volume, so that water collectors and spray pipes are blocked, the fluorine absorption effect is low, the fluorine absorption monitoring result exceeds the standard and cannot meet the environmental protection requirement, and the like; (3) the fluorine absorption displacement water can not be recovered and directly enters a slag discharge system.

Therefore, it is urgently needed to design a system which can effectively reduce the exhaust humidity of the tail gas, reduce the blocking phenomenon and improve the fluorine absorption efficiency and meets the production requirement.

Disclosure of Invention

To the problem that exists among the background art, the utility model provides a fluorine absorption system in phosphoric acid production by wet process can effectively reduce exhaust tail gas area liquid measure, satisfies the environmental protection requirement to, adopted the water replacement circulation use mode, effectively improved fluorine absorption efficiency, simultaneously, establish the filter before the circulating pump import, prevent to receive hydrophone, shower and block up, prolong clearance period, reduce the maintenance cost.

In order to achieve the above purpose, the utility model adopts the following technical scheme: the fluorine absorption system in the wet-process phosphoric acid production comprises a Venturi scrubber, a first washing tower, a gas-liquid separator tower and a second washing tower, wherein water replenishing of the Venturi scrubber, the first washing tower and the second washing tower is connected with a water replenishing pipeline, the outlet of the Venturi scrubber is connected with the first washing tower, the bottom of the Venturi scrubber is connected with an external discharge pump, and the outlet of the Venturi scrubber is connected with the inlet of the first washing tower; a lower layer spray pipe and an upper layer spray pipe are arranged in the first washing tower, the lower layer spray pipe is connected with an outlet of a lower layer circulating pump, an inlet of the lower layer circulating pump is connected with the bottom of the first washing tower, the upper layer spray pipe is connected with an upper layer circulating pump, and an inlet of the upper layer circulating pump is connected with the bottom of the first washing tower; the top of the first washing tower is vented and connected with a gas-liquid separator tower, the gas-liquid separator tower is vented and connected with a second washing tower through a fan, a second spray pipe is arranged in the second washing tower and connected with the outlet of a second circulating pump, the inlet of the second circulating pump is connected with the bottom of the second washing tower, and the top of the second washing tower is provided with an evacuation port.

Preferably, the pipelines between the upper-layer circulating pump and the first washing tower, and between the lower-layer circulating pump and the second washing tower are all provided with filters.

Preferably, valves are provided in the lines on the front and rear sides of each filter.

Preferably, the second spray pipe is arranged in the second washing tower at a height of 7.75-9.75 m, and the water collector is arranged in the second washing tower at a height of 29 m.

The utility model has the advantages that:

the utility model discloses can effectively reduce exhaust tail gas area liquid measure, satisfy the environmental protection requirement to, adopted the displacement water recycling mode, effectively improve fluorine absorption efficiency, simultaneously, establish the filter before the circulating pump import, prevent to receive hydrophone, shower and block up, prolong clearance period, reduce the maintenance cost.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

In the figure: 1-a venturi scrubber, 2-a first washing tower, 3-a gas-liquid separator tower, 4-a second washing tower, 5-an external discharge pump, 6-a lower layer spray pipe, 7-an upper layer spray pipe, 8-an upper layer circulating pump, 9-a lower layer circulating pump, 10-a fan, 11-a second spray pipe, 12-a second circulating pump and 13-a filter.

Detailed Description

In order to make the technical solution and advantages of the present invention clearer, the following will explain in detail a preferred embodiment of the present invention with reference to the accompanying drawings to facilitate understanding of the skilled person.

As shown in fig. 1, the fluorine absorption system in wet-process phosphoric acid production comprises a venturi scrubber 1, a first washing tower 2, a gas-liquid separator tower 3 and a second washing tower 4, wherein water supplement of the venturi scrubber 1, the first washing tower 2 and the second washing tower 4 is connected with a water supplement pipeline, and the water supplement pipeline is connected with process water, circulating water B or dam backwater for supplement and is used as tail gas washing liquid. The outlet of the venturi scrubber 1 is connected with the first scrubbing tower 2, the bottom of the venturi scrubber 1 is connected with an external discharge pump 5, and the outlet of the venturi scrubber 1 is connected with the inlet of the first scrubbing tower 2. The venturi scrubber 1 is a part for washing the tail gas for the first time, and after the washing liquid is mixed and replaced with the tail gas, the concentration of fluosilicic acid in the replacement water is high, so that the replacement water cannot be recycled and is discharged by the discharge pump 5 for treatment. Be provided with lower floor's shower 6 and upper spray 7 in the first scrubbing tower 2, lower floor's shower 6 and lower floor's circulating pump 9 exit linkage, and lower floor's circulating pump 9 import is connected with first scrubbing tower 2 bottoms, and upper spray 7 is connected with upper circulating pump 8, and upper circulating pump 8 import is connected with first scrubbing tower 2 bottoms. Through the continuous washing liquid recycling in with first scrubbing tower 2 of upper circulating pump 8 and lower floor's circulating pump 9, save the water resource, increase fluorine absorption effect simultaneously. The top of the first washing tower 2 is discharged with air and is connected with a gas-liquid separator tower 3 to remove most of liquid drops in the tail gas through sedimentation, the gas-liquid separator tower 3 is discharged with air and is connected with a second washing tower 4 through a fan 10, a second spray pipe 11 is arranged in the second washing tower 4, the second spray pipe 11 is connected with an outlet of a second circulating pump 12, an inlet of the second circulating pump 12 is connected with the bottom of the second washing tower 4, an exhaust port is formed in the top of the second washing tower 4, the second spray pipe 11 is arranged in the second washing tower 4 at a height of 7.75-9.75 meters, a water collector is arranged in the second washing tower 4 at a height of 29 meters, it is ensured that after washing, air has sufficient ascending sedimentation space, residual fine liquid drops are intercepted by the water collector and then return to the second washing tower 4, and finally qualified tail gas is discharged. All be provided with filter 13 on the pipeline between upper circulating pump 8, lower floor's circulating pump 9 and first scrubbing tower 2, between second circulating pump 12 and the second scrubbing tower 4, can filter the silica gel of replacing aquatic production, avoid blockking up shower and receipts hydrophone scheduling problem.

In the wet-process phosphoric acid production process, tail gas from a reaction tank and a digestion tank is introduced into a venturi scrubber 1, water is supplemented through a water supplementing pipeline, the tail gas is scrubbed, the scrubbed tail gas enters a first scrubbing tower 2, a lower layer spray pipe 6 and an upper layer spray pipe 7 on the first scrubbing tower 2 circularly supply water through an upper layer circulating pump 8 and a lower layer circulating pump 9 to scrub the tail gas for two times, then the tail gas is discharged into a gas-liquid separator tower 3 to carry out sedimentation gas-liquid separation, the separated liquid phase is discharged through a bottom sewage discharge pipe, the gas phase is sent into a second scrubbing tower 4 through a fan 10, a second spray pipe 11 is circularly supplied water through a second circulating pump 12 to continuously spray the tail gas, fluorine in the tail gas is absorbed again, the scrubbed tail gas continues to rise for a certain distance, liquid drops in the tail gas are fully settled, and finally the qualified tail gas is discharged into the atmosphere.

In the production process, the system needs to be cleaned and drained regularly. All be provided with the valve on the pipeline of each filter 13 front side and rear side, close the valve around filter 13 during the blowdown, open filter 13 upper cover plate and bottom connection blind plate, wash the silica gel of filter with the water, take out the filter, the material of clearance jam on the filter pore is accomplished the filter blowdown and is washd.

Finally, it is noted that the above-mentioned preferred embodiments illustrate rather than limit the invention, and that, although the invention has been described in detail with reference to the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention as defined by the appended claims.

Claims (4)

1. A fluorine absorption system in wet process phosphoric acid production, which is characterized in that: the device comprises a Venturi scrubber (1), a first washing tower (2), a gas-liquid separator tower (3) and a second washing tower (4), wherein water replenishing of the Venturi scrubber (1), the first washing tower (2) and the second washing tower (4) is connected with a water replenishing pipeline, the air outlet of the Venturi scrubber (1) is connected with the first washing tower (2), the bottom of the Venturi scrubber (1) is connected with an external discharge pump (5), and the air outlet of the Venturi scrubber (1) is connected with the air inlet of the first washing tower (2); a lower layer spray pipe (6) and an upper layer spray pipe (7) are arranged in the first washing tower (2), the lower layer spray pipe (6) is connected with an outlet of a lower layer circulating pump (9), an inlet of the lower layer circulating pump (9) is connected with the bottom of the first washing tower (2), the upper layer spray pipe (7) is connected with an upper layer circulating pump (8), and an inlet of the upper layer circulating pump (8) is connected with the bottom of the first washing tower (2); the top of the first washing tower (2) is vented and connected with the gas-liquid separator tower (3), the gas-liquid separator tower (3) is vented and connected with the second washing tower (4) through a fan (10), a second spray pipe (11) is arranged in the second washing tower (4), the second spray pipe (11) is connected with an outlet of a second circulating pump (12), an inlet of the second circulating pump (12) is connected with the bottom of the second washing tower (4), and the top of the second washing tower (4) is provided with an evacuation port.

2. The system for absorbing fluorine in wet-process phosphoric acid production according to claim 1, wherein: and the pipelines between the upper-layer circulating pump (8), the lower-layer circulating pump (9) and the first washing tower (2) and between the second circulating pump (12) and the second washing tower (4) are respectively provided with a filter (13).

3. The fluorine absorption system in wet-process phosphoric acid production according to claim 2, characterized in that: valves are arranged on the pipelines at the front side and the rear side of each filter (13).

4. The system for absorbing fluorine in wet-process phosphoric acid production according to claim 1, wherein: the second spray pipe (11) is arranged in the second washing tower (4) with the height of 7.75-9.75 m, and a water collector is arranged in the second washing tower (4) with the height of 29 m.

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