Wet-process phosphoric acid disc washing system

Abstract

The invention discloses a wet-process phosphoric acid plate washing system, which belongs to the technical field of phosphoric acid preparation process, and comprises a plate washing area, a filtrate area, a first washing area, a thick slurry area, a second washing area and a third washing area which are connected in sequence, and further comprises a liquid storage container, the liquid storage container is connected with the plate flushing area through the plate flushing pump to inject water into the plate flushing area, and the plate flushing area is connected with the first washing area through the washing pump to inject water into the first washing area. The disc flushing pump is connected with the liquid storage container to inject water into the disc flushing area, so that the water quality of the disc flushing pump is improved, the possibility that the disc flushing pump is blocked is greatly reduced, the service life of the disc flushing pump is prolonged, and the disc flushing effect and the disc flushing efficiency are improved; the redundant part is injected into the second washing area, and the thick slurry area is used for second washing, so that the washing effect and the washing efficiency can be improved under the condition that the washing water amount is not increased.

Description

Technical Field

[0001] The invention relates to the technical field of phosphoric acid preparation technology, and in particular to a wet phosphoric acid wash plate washing system. Background Art

[0002] Wet phosphoric acid process is used to produce dilute phosphoric acid. The phosphoric acid slurry prepared by the reaction of phosphate rock and sulfuric acid is separated into liquid and solid by a rotary filter to produce dilute phosphoric acid. In the process of wet phosphoric acid filtration production, the filter flushing system and washing system are the two core elements that determine the energy efficiency improvement of phosphoric acid production. At present, it is mainly carried out in a mode combining flushing and washing cycles, and the filter flushing water is recycled in multiple stages in series.

[0003] The operation process causes the filter flushing pump in the washing process to use filter cloth washing water, commonly known as cloth water. However, cloth water contains a large amount of filter gypsum, and the flushing pump and filter are prone to blockage, which has an adverse effect on the production cycle, flushing effect, production load, solid-liquid ratio and washing efficiency of the filtration system. The present invention proposes a new solution to the above problems. Summary of the invention

[0004] In order to overcome at least one of the above disadvantages, the present invention provides a wet phosphoric acid wash plate washing system. The purpose of the present invention can be achieved by adopting the following technical solutions:

[0005] The present invention provides a wet phosphoric acid wash pan system, comprising a wash pan area, a filtrate area, a first washing area, a thick slurry area, a second washing area and a third washing area connected in sequence. The wet phosphoric acid wash pan system also comprises a liquid storage container, the liquid storage container is connected to the wash pan area through a wash pan pump for injecting water into the wash pan area, and the wash pan area is connected to the first washing area through a washing pump for injecting water into the first washing area.

[0006] In one embodiment, the water source of the liquid storage container includes condensed water from a concentration system and circulating water from a filtered condenser.

[0007] In one possible implementation, the water source of the liquid storage container also includes purified sewage.

[0008] In one possible implementation manner, the wash plate area is connected to the second wash area via a wash pump for injecting water into the second wash area.

[0009] In one possible implementation manner, the wash plate area is connected to the third wash area via a wash pump for injecting water into the third wash area.

[0010] In one embodiment, the water source of the second washing zone further comprises sewage pond water.

[0011] In one possible implementation, a material stopper is provided between the punching plate area and the filtrate area, and the material stopper comprises a stopper lining cloth.

[0012] In one possible implementation manner, the material-blocking skin and the skin-blocking lining cloth are both made of rubber, and the hardness of the skin-blocking lining cloth is lower than that of the material-blocking skin.

[0013] In one possible implementation, the height of the material blocking skin is 0.2m-0.5m.

[0014] In one embodiment, anti-cross-liquid baffles are provided between the filtrate zone and the first washing zone, between the first washing zone and the thick slurry zone, and between the thick slurry zone and the second washing zone.

[0015] Beneficial technical effects of the present invention: According to the contents of the present disclosure, the wet-process phosphoric acid wash plate system comprises a wash plate area, a filtrate area, a first washing area, a thick slurry area and a second washing area which are connected in sequence, and a wash plate pump is connected to a liquid storage container to inject water into the wash plate area, thereby improving the water quality passing through the wash plate pump, greatly reducing the possibility of the wash plate pump being blocked, eliminating the need for frequent cleaning of the wash plate pump, reducing the operating intensity, increasing the service life of the wash plate pump, and improving the wash plate effect and wash plate efficiency, and injecting the filtered water from the wash plate area into the first washing area through a washing pump, and injecting the excess water into the second washing area, using the thick slurry area as the second wash, and the gypsum in the filtrate area is thinner after filtration, which can improve the washing effect and washing efficiency without increasing the amount of washing water. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In the accompanying drawings, the following are given by way of example and not limitation:

[0017] Figure 1 The overall process diagram of the present invention is shown;

[0018] Figure 2 The schematic diagram of the conventional wet phosphoric acid wash pan washing system is shown;

[0019] Figure 3 The schematic diagram of the material stopper skin and the stopper skin lining cloth structure of the present invention is shown.

[0020] In the figure: 1, flushing plate area; 2, filtrate area; 3, first washing area; 4, thick slurry area; 5, second washing area; 6, third washing area; 7, liquid storage container; 8, flushing plate pump; 9, washing pump; 10, filter; 11, material retaining skin; 12, retaining skin lining cloth. DETAILED DESCRIPTION

[0021] In the following detailed disclosure, these embodiments are fully described with reference to the accompanying drawings. In order to make the technical scheme of the present invention more clear and specific to those skilled in the art, the implementation methods described below are not limited to this. The present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings.

[0022] In the present invention, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance; the term "plurality" refers to two or more, unless otherwise clearly defined. The terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “front” and “back” are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore, cannot be understood as a limitation on the present invention.

[0024] In the dilute acid production process, Figure 2 As shown, because the filter disc pump 8 uses the filter cloth washing water, commonly known as cloth water, which contains a large amount of filter gypsum, when there is a leak in the filter cloth, larger particles will be mixed into the cloth water, and the disc pump 8 and its filter 10 are easy to be blocked. When the disc pump 8 branch pipe is blocked, it will have an adverse effect on the filter suction, washing rate, production load and liquid-solid ratio indicators. At present, the filter disc system can only ensure the smooth flow of the disc pipe by increasing the cleaning frequency. The cleaning frequency is as high as 8-10 times / d. When cleaning, a hook is used to dredge the blocked branch pipe, which is difficult to operate, and the on-site cleaning environment is poor and the temperature is high. If it is not discovered in time, the disc branch pipe will be completely blocked, which will seriously affect the disc effect and the filter cloth regeneration effect, resulting in substandard washing rate, high gypsum water content, shortened filter cloth service life, and reduced dilute acid production efficiency.

[0025] like Figure 1 As shown, the present invention provides a wet phosphoric acid wash pan system, comprising a wash pan area 1, a filtrate area 2, a first washing area 3, a thick slurry area 4, a second washing area 5 and a third washing area 6 connected in sequence, the wet phosphoric acid wash pan system also includes a liquid storage container 7, the liquid storage container 7 is connected to the wash pan area 1 through a wash pan pump 8 for injecting water into the wash pan area 1, and the wash pan area 1 is connected to the first washing area 3 through a washing pump 9 for injecting water into the first washing area 3.

[0026] The wet-process phosphoric acid wash plate system comprises a wash plate area 1, a filtrate area 2, a first washing area 3, a thick slurry area 4 and a second washing area 5 which are connected in sequence, and a wash plate pump 8 is connected to a liquid storage container 7 to inject water into the wash plate area 1, thereby improving the water quality passing through the wash plate pump 8, preventing the wash plate pump 8 from being blocked by impurities in the wash plate area 1, and eliminating the need for frequent cleaning of the wash plate pump 8, thereby reducing the work intensity, increasing the service life of the wash plate pump 8, and improving the wash plate effect and wash plate efficiency.

[0027] The wet phosphoric acid wash pan washing system injects the filtered water from the wash pan area 1 into the first washing area 3 through the washing pump 9, and the excess is injected into the second washing area 5. The thick slurry area 4 is used as the second washing. The gypsum is thinner after filtering in the filtrate area 2, which can improve the washing effect and efficiency without increasing the amount of washing water.

[0028] In the traditional flushing disc system, the slurry from the slurry pump is evenly distributed to the filter disc of the filter by the distributor, and passes through the filtrate area 2, the thick slurry area 4, the second washing area 5, the third washing area 6, suction, unloading, flushing and other processes in sequence. The washed gypsum is discharged by the spiral, and then rinsed clean by the flushing disc and re-filtered. The sewage after the flushing disc enters the system as a washing water. The thick slurry area 4 of the first washing uses the flushing water from the flushing disc pump 8. The flushing water contains a large amount of gypsum, which is about one-third of the total gypsum thickness, affecting the washing effect. The second washing area 5 mainly uses the sewage pool to recycle sewage, and the third washing area 6 mainly uses the circulating water return water of the filter condenser and the concentrated condensed water.

[0029] In one possible implementation manner, the present application provides a water source composition of a liquid storage container 7, including condensed water from a concentration system and circulating water from a filtered condenser.

[0030] Among them, the flushing disc pump 8 adopts the circulating water and condensed water with good water quality in the liquid storage container 7. By improving the water quality passing through the flushing disc pump 8, there is no need to install the filter 10. At the same time, there is no need to frequently clean the flushing disc pump nozzle, which reduces the frequency of cleaning, reduces the work intensity, improves the filtering efficiency, and increases the service life of the flushing disc pump 8.

[0031] Furthermore, the water source of the liquid storage container 7 also includes purified sewage. When the sewage pressure is high, a part of the purified sewage can be used for supplementation to ensure water balance.

[0032] The water from the filter cloth is directly sent to the first washing zone 3 by the flushing plate pump 8 as a wash water. The flushing plate pump 8 can use a small nozzle, such as a 3mm nozzle. The overall water consumption does not change much and has no effect on the water balance of the extraction reaction.

[0033] Among them, the water source of the flushing area 1 also includes low-flash liquid sealing tank water.

[0034] In one embodiment, the wash plate area 1 is connected to the second wash area 5 via a wash pump 9 for injecting water into the second wash area 5 .

[0035] The wash plate area 1 is connected to the third wash area 6 via a wash pump 9 for injecting water into the third wash area 6 .

[0036] It can be understood that the flushing plate pump 8 delivers the water with good water quality in the liquid storage container 7 to the flushing plate area 1, and the water in the flushing plate area 1 passes through the washing pump 9 without passing through the filter 10, and is directly delivered to the first washing area 3 as the first washing water. The excess water in the first washing area 3 enters the second washing area 5 as the second washing water, and the excess water in the second washing area 5 enters the third washing area 6 as the third washing water, which can improve the water quality and washing effect of the overall washing system.

[0037] In one embodiment, the water source of the second washing zone 5 also includes sewage pond water.

[0038] It can be understood that the excess water from the first washing zone 3 enters the second washing zone 5 together with the sewage pool water as secondary wash water to ensure water balance.

[0039] Traditionally, two retaining skins 11 are arranged between the flushing plate area 1 and the filtrate area 2. The two retaining skins 11 are arranged in parallel on the bracket above the filter cloth. There is a certain distance between the two retaining skins 11. After the filter cloth is flushed by the flushing plate area 1, the first retaining skin 11 is in direct contact with the filter cloth, causing wear to the filter cloth. After the retaining skin 11 is used for a period of time and partially aged, the wear to the filter cloth becomes more serious. At the same time, the height of the retaining skin 11 is generally 0.8m-1m. The retaining skin 11 is easy to swing during the contact process with the filter cloth, which increases the wear on the filter cloth, resulting in a short service life of the filter cloth and many leakage points.

[0040] In one possible implementation, Figure 3 As shown, a retaining skin 11 is provided between the punching plate area 1 and the filtrate area 2 , and the retaining skin 11 includes a retaining skin lining cloth 12 .

[0041] It can be understood that the space between the punching plate area 1 and the filtrate area 2 is reduced to a material stopper skin 11, and a material stopper skin lining cloth 12 is provided on the material stopper skin 11, such as Figure 3 As shown, the stopper skin lining cloth 12 is arranged at the bottom of the material stopper skin 11, so that the stopper skin lining cloth 12 contacts the filter cloth first, thereby reducing the wear of the material stopper skin 11 on the filter cloth.

[0042] Furthermore, the material-blocking skin 11 and the skin-blocking lining cloth 12 are both made of rubber, and the hardness of the skin-blocking lining cloth 12 is lower than that of the material-blocking skin 11 .

[0043] By setting a flexible rubber stopper lining 12 at the bottom of the hard rubber stopper 11, the flexible rubber stopper lining 12 can be in contact with the filter cloth. Under the premise of ensuring material blocking, the wear on the filter cloth is reduced, the frequency of filter cloth replacement is reduced, and the cost is reduced.

[0044] The height of the material-blocking skin 11 is 0.2m-0.5m. By lowering the height of the material-blocking skin 11, the swing amplitude of the material-blocking skin 11 when in contact with the filter cloth is reduced while ensuring that the material can be blocked, thereby further reducing the wear on the filter cloth.

[0045] In this embodiment, the height of the material blocking skin 11 is taken as 0.3m±0.05m as an example. In specific implementation, it can not only ensure the need for material blocking, but also has a small swing amplitude, which greatly reduces the wear on the filter cloth.

[0046] In one embodiment, anti-cross-liquid baffles are provided between the filtrate zone 2 and the first washing zone 3 , between the first washing zone 3 and the thick pulp zone 4 , and between the thick pulp zone 4 and the second washing zone 5 .

[0047] Among them, by setting anti-liquid cross-contamination barriers between different areas, the occurrence of liquid cross-contamination between different areas can be reduced, the independence of different areas can be guaranteed, mutual contamination can be avoided, the amount of washing water can be increased, and the washing effect can be improved.

[0048] It is understood that the filtration process uses filter cloth as the filter medium. On the rotary filter, the phosphoric acid in the slurry is separated from the gypsum by the vacuum effect, and the large amount of phosphoric acid adsorbed on the gypsum is fully removed and recovered by the parallel flow washing method. The amount of gypsum and other solid impurity particles in the slurry of the extraction process is huge, and its weight is about 1.5 times the weight of phosphate rock. The amount of washing water is very limited, only 0.68 times the weight of gypsum.

[0049] In specific implementation, the wet phosphoric acid wash plate system provided by the present application evenly distributes the slurry from the slurry pump to the filter plate of the filter by the distributor, and sequentially passes through the filtrate area 2, the first washing area 3, the thick slurry area 4, the second washing area 5, and the third washing area 6. After the processes of drying, unloading, and wash plates, the cleaned gypsum is unloaded to the conveyor belt by the unloading screw, and the filtrate is sent to the storage tank by the filtrate pump after separation. The wet phosphoric acid wash plate system can improve the washing efficiency and washing effect under the condition of the same washing water volume, and can also reduce the blockage of the wash plate pump 8, reduce the work intensity of the operators, reduce the wear of the filter cloth, and increase the service life of the wash plate pump 8 and the filter cloth, reduce the cost, and have a high economic benefit.

[0050] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0051] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0052] In view of the above detailed description, these and other changes can be made to these embodiments, and this written description includes the best mode embodiments to disclose the present invention. The scope of the patent obtained by the present invention is defined by the claims, which are not limited by the present disclosure, and the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field within the scope disclosed by the present invention, according to the technical solution and its conception of the present invention, is equivalent to or changes, and all are within the protection scope of the present invention.

Claims

1. A wet phosphoric acid wash plate washing system, characterized in that: The wet-process phosphoric acid wash system comprises a wash plate area (1), a filtrate area (2), a first washing area (3), a thick slurry area (4), a second washing area (5) and a third washing area (6) which are connected in sequence. The wet-process phosphoric acid wash plate system further comprises a liquid storage container (7). The liquid storage container (7) is connected to the wash plate area (1) via a wash plate pump (8) for injecting water into the wash plate area (1). The wash plate area (1) is connected to the first washing area (3) via a washing pump (9) for injecting water into the first washing area (3).

2. A wet phosphoric acid wash plate washing system according to claim 1, characterized in that: The water source of the liquid storage container (7) includes condensed water from the concentration system and circulating water from the filter condenser.

3. A wet phosphoric acid wash plate washing system according to claim 2, characterized in that: The water source of the liquid storage container (7) also includes purified sewage.

4. A wet phosphoric acid wash plate washing system according to claim 1, characterized in that: The wash plate area (1) is connected to the second wash area (5) via a wash pump (9) for injecting water into the second wash area (5).

5. A wet phosphoric acid wash plate washing system according to claim 1, characterized in that: The wash plate area (1) is connected to the third wash area (6) via a wash pump (9) for injecting water into the third wash area (6).

6. A wet phosphoric acid wash plate washing system according to claim 4, characterized in that: The water source of the second washing zone (5) also includes sewage pool water.

7. A wet phosphoric acid wash plate washing system according to claim 1, characterized in that: A material-blocking skin (11) is provided between the punching plate area (1) and the filtrate area (2), and the material-blocking skin (11) comprises a material-blocking skin lining cloth (12).

8. A wet phosphoric acid wash pan scrubbing system according to claim 7, characterized in that: The material-blocking skin (11) and the skin-blocking lining cloth (12) are both made of rubber, and the hardness of the skin-blocking lining cloth (12) is lower than the hardness of the material-blocking skin (11).

9. A wet phosphoric acid wash plate washing system according to claim 7 or 8, characterized in that: The height of the material blocking skin (11) is 0.2m-0.5m.

10. A wet phosphoric acid wash pan system according to claim 1, characterized in that: Anti-cross-liquid baffles are provided between the filtrate zone (2) and the first washing zone (3), between the first washing zone (3) and the thick pulp zone (4), and between the thick pulp zone (4) and the second washing zone (5).

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