CN212799924U - Water circulation system for wet-process phosphoric acid production - Google Patents

Abstract

The utility model discloses a water circulating system is used in phosphoric acid by wet process production, including first water catch bowl and second water catch bowl, the hydrologic cycle flow relation as follows: the fresh process water is respectively connected with the vacuum pump of the extraction system and the vacuum pump of the concentration system, and effluent flows back to the first water collecting tank; then the water is conveyed to a vacuum pump of a filtering system through a pump, and the outlet water flows back to a second water collecting tank; then respectively conveying the mixture to a tail gas washing system through a pump to be used as water supplement, a tail gas fan impeller to be used as washing water and a filtering system to be used as four-washing water; the outlet water overflows to a filter cloth washing water tank, and water in the filter cloth washing water tank is conveyed to a filter cloth washing area through a pump to be used as filter cloth disc washing water; washing water of the filtering system flows back to the reactive extraction tank after countercurrent; by the scheme, the equipment water in the original production system can be adjusted according to the using, cooling and reusing processes to be realized according to the quality of water and the heat energy, and the method optimizes the utilization of water resources and distributes the water in the system according to the heat energy.

Description

Water circulation system for wet-process phosphoric acid production

Technical Field

The utility model belongs to the technical field of phosphoric acid production, concretely relates to phosphoric acid by wet process water circulating system.

Background

The wet-process phosphoric acid is a mature technical means in the current phosphoric acid production, but the process needs a large amount of water to be used as sealing water of a pump and circulating water of a vacuum pump, and the water consumption is huge. The water used by vacuum equipment in the existing wet-process phosphoric acid production process has two parts of sources: one part is fresh process water, the other part is water obtained by cooling hot water discharged by vacuum equipment through small circulating water, and the two parts are mixed and then added into the vacuum equipment together to provide operation guarantee. In the process, water discharged by the vacuum equipment of the concentration system and water discharged by the vacuum equipment of the extraction reaction system belong to micro hot water, and the temperature rise is not obvious compared with the added process water. But the part of water is directly discharged into the filter cloth washing water tank, so that the temperature of hot water returning through the atmospheric condenser is reduced by 3-5 ℃, and the reduction of the temperature is not beneficial to filter cloth washing and gypsum regeneration in the filtering stage.

The water used by the vacuum equipment of the filtering system is consistent with the water used by the vacuum equipment of the extraction reaction system in source, but the water consumption is smaller than that of the vacuum equipment of the extraction reaction system. However, the water discharged by the vacuum filtration equipment has high temperature, the hot water directly enters the small circulating water system for air cooling and cooling, the heat cannot be effectively recycled, and a large amount of fluorine-containing waste gas is discharged in the cooling and cooling process of the small circulating water system to pollute the surrounding environment. Furthermore, since the company has to return a large part of the steam condensate to the power plant when using the power plant condensate. Therefore, the washing water consumption of the filtering system is seriously insufficient, the washing rate in the phosphoric acid production process is reduced, and the total phosphorus recovery rate is reduced.

SUMMERY OF THE UTILITY MODEL

The utility model provides a wet process phosphoric acid process water circulation system, aim at solve the current phosphoric acid production in the water consumption great, the problem of the unreasonable and water inefficiency of water consumption.

Therefore, the utility model adopts the following technical scheme:

the utility model provides a wet process phosphoric acid process water circulating system, wet process phosphoric acid process system includes extraction system, filtration system, concentrated system and tail gas washing system, still includes first water catch bowl and second water catch bowl, and the bottom of first water catch bowl and second water catch bowl passes through the pipeline intercommunication, and the water circulation flow relation is as follows:

fresh process water is respectively connected with an extraction system vacuum pump and a concentration system vacuum pump through pipelines, and effluent of the extraction system vacuum pump and the concentration system vacuum pump flows back to a first water collecting tank; water in the first water collecting tank is conveyed to a vacuum pump of a filtering system through a pump, and water output by the vacuum pump of the filtering system flows back to the second water collecting tank; water in the second water collecting tank is respectively conveyed to a tail gas washing system through a pump to be used as water supplement, a tail gas fan impeller is used as washing water, and a filtering system is used as four-washing water; the countercurrent outlet water of the tail gas washing system and the washing outlet water of the tail gas fan impeller overflow to a filter cloth washing water tank, and the water in the filter cloth washing water tank is conveyed to a filter cloth washing area through a pump to be used as filter cloth disc washing water; washing water of the filtering system flows back to the reactive extraction tank after countercurrent;

and the sealing water and the cooling water of the extraction system, the filtering system and the concentration system are converged to an underground water tank through a trench, and are conveyed to a tail gas washing system through a pump after being filtered to be used as water supplement.

The utility model has the advantages as follows: by the scheme, the equipment water in the original production system can be adjusted according to the using, cooling and reusing processes to be realized according to the quality of water and the heat energy, the method optimizes the utilization of water resources, distributes the water in the system according to the heat energy and is beneficial to the stable operation of an extraction reaction system; the washing effect of the filter cloth is improved, the condensate for washing is saved, the original small water circulating system for vacuum equipment is omitted, the waste gas discharged into the atmosphere is reduced, and the economic and environmental benefits are obvious.

Drawings

FIG. 1 is a schematic diagram of the system of the present invention;

in the figure: 1-a first water collecting tank, 2-a second water collecting tank, 3-an extraction system vacuum pump, 4-a concentration system vacuum pump, 5-a filtration system vacuum pump and 6-a filter cloth washing water tank.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings:

as shown in fig. 1, a water circulation system for wet-process phosphoric acid production, the wet-process phosphoric acid production system includes an extraction system, a filtration system, a concentration system and a tail gas washing system, and further includes a first water collecting tank 1 and a second water collecting tank 2, and the bottoms of the first water collecting tank 1 and the second water collecting tank 2 are communicated through a pipeline, and the water circulation flow relationship is as follows:

a. the fresh process water is respectively connected with an extraction system vacuum pump 3 and a concentration system vacuum pump 4 through pipelines;

b. water discharged by the extraction system vacuum pump 3 and the concentration system vacuum pump 4 flows back to the first water collecting tank 1; water in the first water collecting tank 1 is conveyed to a vacuum pump 5 of a filtering system through a pump;

c. the water discharged by the vacuum pump 5 of the filtering system flows back to the second water collecting tank 2, the water in the second water collecting tank 2 is respectively conveyed to the tail gas washing system through a pump to be used as water supplement, the tail gas fan impeller is used as washing water, and the filtering system is used as four-washing water;

d. washing water of the filtering system flows back to the reactive extraction tank after countercurrent;

e. the countercurrent outlet water of the tail gas washing system and the washing outlet water of the tail gas fan impeller overflow to a filter cloth washing water tank 6, and the water in the filter cloth washing water tank is conveyed to a filter cloth washing area through a pump to be used as filter cloth disc washing water;

f. and the sealing water and the cooling water of the extraction system, the filtering system and the concentration system are converged to an underground water tank through a trench, and are conveyed to a tail gas washing system through a pump after being filtered to be used as water supplement.

When the existing phosphoric acid production is improved, a first water collecting tank 1 and a second water collecting tank 2 are added, pipelines for communicating are arranged at the bottoms of the first water collecting tank 1 and the second water collecting tank 2, and backflow pipelines are erected between the effluent of an extraction system vacuum pump 3 and a concentration system vacuum pump 4 and the first water collecting tank 1; a pipeline and a pump are erected between the first water collecting tank 1 and the filtering system vacuum pump 5 and used for conveying water to the filtering system vacuum pump 5; and pipelines and pumps are respectively erected between the second water collecting tank 2 and the four washing areas of the tail gas washing system, the tail gas fan impeller and the filtering system, and are used for providing tail gas washing water, tail gas fan impeller washing water and filtering system four washing water.

The principle of the utility model is as follows:

in the water circulation system, an extraction system vacuum pump 3 and a concentration system vacuum pump 4 are the only water replenishing equipment for process water, and the process water is at normal temperature; the temperature of the process water slightly rises by 3-5 ℃ after passing through the vacuum pump 3 of the extraction system and the vacuum pump 4 of the concentration system, and the fluorine content in the water slightly rises; the water temperature and the fluorine content of the water flow in the first water collecting tank 1 are obviously increased after passing through a vacuum pump 5 of a filtering system; most of water in the second water collecting tank 2 is conveyed by a pump to flow through a tail gas washing system and a tail gas fan impeller and then overflows into a filter cloth washing water tank; conveying a small amount of water in the second water collecting tank 2 through a pump to serve as a filtering system to serve as a four-washing area, and returning the water to the extraction reaction system after the water is subjected to counter-current washing through the filtering system; filter cloth washing disc water descending water returns to the extraction reaction system after being washed by a filter system in a counter-current manner; and returning the water in the underground water tank to the tail gas washing system for recycling.

The working procedures d, e and f of the utility model belong to the recycling water in the whole water system, wherein the externally input condensate in the working procedure d is replaced by part of high-temperature water in the working procedure c, and then enters the reactive extraction tank after countercurrent washing, thereby reducing the consumption of the external condensate; the original process water in the step e is replaced by part of the high-temperature water in the step c, so that the use amount of the process water is reduced; and f, the water quality in the step f is poor, other solid-phase impurities are often contained, the water is filtered by a filter screen and then is conveyed to a tail gas washing system to be used as make-up water, the water temperature of the water is normal temperature, the water temperature of the tail gas washing liquid can be reduced, the tail gas washing liquid can be replaced, and therefore the washing effect is improved.

It should be noted that the above are only some embodiments of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.

Claims (1)

1. The utility model provides a wet process phosphoric acid process water circulating system, wet process phosphoric acid process production system include extraction system, filtration system, concentrated system and tail gas washing system, its characterized in that still includes first water catch bowl and second water catch bowl, and the pipeline intercommunication is passed through to the bottom of first water catch bowl and second water catch bowl, and the hydrologic cycle flow relation is as follows:

fresh process water is respectively connected with an extraction system vacuum pump and a concentration system vacuum pump through pipelines, and effluent of the extraction system vacuum pump and the concentration system vacuum pump flows back to a first water collecting tank; water in the first water collecting tank is conveyed to a vacuum pump of a filtering system through a pump, and water output by the vacuum pump of the filtering system flows back to the second water collecting tank; water in the second water collecting tank is respectively conveyed to a tail gas washing system through a pump to be used as water supplement, a tail gas fan impeller is used as washing water, and a filtering system is used as four-washing water; the countercurrent outlet water of the tail gas washing system and the washing outlet water of the tail gas fan impeller overflow to a filter cloth washing water tank, and the water in the filter cloth washing water tank is conveyed to a filter cloth washing area through a pump to be used as filter cloth disc washing water; washing water of the filtering system flows back to the reactive extraction tank after countercurrent;

and the sealing water and the cooling water of the extraction system, the filtering system and the concentration system are converged to an underground water tank through a trench, and are conveyed to a tail gas washing system through a pump after being filtered to be used as water supplement.

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