Process and system for reducing hydrolyzate acid value in dimethyldichlorosilane hydrolyzate separation wash process

Abstract

The present application relates to the process and system for reducing the acid value of dimethyldichlorosilane hydrolysate in the separation and washing process. The three-stage coalescer is arranged, the acidic hydrolysate of dimethyldichlorosilane enters the system from the first-stage coalescer, the process water enters the system from the third-stage coalescer, the acidic hydrolysate is mixed with dilute hydrochloric acid or process water in each coalescer, the oil-water two-phase separation is completed through multiple washing and coalescing, and the acid value of the hydrolysate is reduced; each coalescer comprises two series static mixers, a group of pre-filters, and a large coalescer, the coalescer is in the shape of Z, and each coalescer contains four filter cores. Through repeated tests, the modified polyvinylidene fluoride filter core of Dowell is finally selected, and after the continuous three-stage coalescer treatment, the acid value of the dimethyldichlorosilane hydrolysate can be reduced to below 10 PPM.

Description

TECHNICAL FIELD

[0001] The present application relates to a process and system device for reducing the acid value of dimethyldichlorosilane hydrolysate in the separation and washing process. This coalescing device greatly reduces the chloride ion content in the hydrolysis product while reducing the amount of make-up water. It belongs to the technical field of organosilicon. BACKGROUND

[0002] Currently, most of the neutral hydrolysate produced by domestic organosilicon monomer manufacturers adopts a weak alkali neutralization-water washing separation process. This process has a long hydrolysate residence time, involves more equipment for reaction, storage and separation, and results in high chloride ion content and high viscosity of the obtained neutral hydrolysate. In addition, pure alkali needs to be introduced to neutralize the hydrolysate during the purification process, supplemented by a large amount of process water for boiling and washing purification. During this period, the washing kettle consumes steam and generates a large amount of alkaline wastewater that needs to be treated, which is not conducive to the construction of a resource-saving and environment-friendly society. SUMMARY

[0003] In view of the above technical problems, the present application provides a process and system device for reducing the acid value of dimethyldichlorosilane hydrolysate in the separation and washing process. The device includes a continuous multi-stage coalescer device, preferably a three-stage coalescer device. Dimethyldichlorosilane acidic hydrolysate enters the system from the first-stage coalescer, and process water enters the system from the third-stage coalescer. In each coalescer, the acidic hydrolysate is mixed with dilute hydrochloric acid or process water, and after multiple washing and coalescing, oil-water two-phase separation is completed, and the acid value of the hydrolysate is reduced. Each coalescer includes two series static mixers, a set of pre-filters, and a large coalescer in the shape of "Z". Each coalescer contains four filter cartridges. Through repeated tests, the modified polyvinylidene fluoride filter cartridge of the Pall Corporation was finally selected. After being treated by the continuous three-stage coalescer, the acid value of the dimethyldichlorosilane hydrolysate can be reduced to below 10 PPM. This coalescing device replaces the traditional alkali washing + water washing method of acidic hydrolysate, greatly reduces the generation of wastewater while reducing the acid value of the hydrolysate, and avoids the high energy consumption and large pollution of the traditional multi-stage alkali washing-water washing process.

[0004] The device includes at least one coalescer device, which includes a hydrolysate pipeline connected to a static mixer, a static mixer connected to a pre-filter, a pre-filter connected to a coalescer, and a coalescer connected to a finished hydrolysate product area.

[0005] The static mixer is a two-stage static mixer connected in series. The static mixer can mix the dimethylsiloxane acidic hydrolysate with water sufficiently, which is beneficial to reducing the chloride ion content and the acid value of the hydrolysate.

[0006] The pre-filter is a two-stage same pre-filter connected in series. The pre-filter removes impurities in the oil-water mixture, preventing impurities from clogging the coalescer filter element, protecting the coalescer filter element from being clogged and damaged, and also reducing the emulsification of the mixture.

[0007] The first filter element-containing horizontal unit is connected to the lower part of the second filter element-containing vertical unit, the upper part of the second filter element-containing vertical unit is connected to the third filter element-containing horizontal unit, and the third filter element-containing horizontal unit is connected to the lower part of the fourth filter element-containing vertical unit.

[0008] The filter element in the first filter element-containing horizontal unit is arranged in the middle of the first filter element-containing horizontal unit, and cavities are formed at both ends of the first filter element-containing horizontal unit. The front end cavity is a buffer zone for the hydrolysis mixture filtered by the pre-filter, allowing the hydrolysis mixture to pass through the first filter element for coalescence and separation, and enter the end cavity.

[0009] The filter element in the second filter element-containing vertical unit is arranged in the middle of the second filter element-containing vertical unit, and cavities are formed at both ends of the second filter element-containing vertical unit. In some embodiments, it can be seen that the middle means the inside, and the filter element is arranged in a position to form cavities at both ends, and the cavity volumes can be the same or different.

[0010] The first filter element-containing horizontal unit is connected to the lower end cavity of the second filter element-containing vertical unit.

[0011] In some embodiments, it can be understood that after the first filter element-containing horizontal unit is filtered, the hydrolysis mixture enters the lower end cavity of the second filter element-containing vertical unit from the end cavity of the first filter element-containing horizontal unit, and after the hydrolysis mixture gradually accumulates, the filter element in the second filter element-containing vertical unit filters upward, and the filtered material enters the upper cavity of the second filter element-containing vertical unit.

[0012] In some embodiments, it can be understood that the length of the second filter element-containing vertical unit is much longer than the length of the first filter element-containing horizontal unit, such as 10-50 times longer. The length of the lower cavity of the second filter element-containing vertical unit is much longer than the length of the first filter element-containing horizontal unit, such as 5-20 times longer, to achieve a long enough buffer time and buffer zone, so that the hydrolysis mixture filtered by the first filter element-containing horizontal unit accumulates and settles in the lower cavity, and oil and water are separated, the water phase sinks, the oil phase floats, and the oil phase is filtered by the filter element under the action of the water phase.

[0013] In some embodiments, it can be understood that the length of the upper cavity of the second vertical unit containing filter cartridges is much greater than the length of the third horizontal unit containing filter cartridges, such as 5-20 times, to achieve a long enough buffer time and buffer zone, so that the filtered oil phase in the second vertical unit containing filter cartridges overflows and slowly enters the third horizontal unit containing filter cartridges.

[0014] The filter cartridges in the third horizontal unit containing filter cartridges are arranged in the middle of the third horizontal unit containing filter cartridges, and cavities are formed at both ends of the third horizontal unit containing filter cartridges; one end cavity is connected with the upper end cavity of the second vertical unit containing filter cartridges, and the other end cavity is connected with the fourth vertical unit containing filter cartridges.

[0015] In some embodiments, it can be understood that the one end cavity receives the hydrolysis mixture overflowing from the upper end cavity of the second vertical unit containing filter cartridges, and the hydrolysis mixture is filtered through the filter cartridges and then enters the end cavity.

[0016] The first horizontal unit containing filter cartridges and the third horizontal unit containing filter cartridges can have the same structure and the same filter cartridge position.

[0017] The filter cartridges in the fourth vertical unit containing filter cartridges are arranged in the upper part of the fourth vertical unit containing filter cartridges, and a cavity is formed in the lower part of the fourth vertical unit containing filter cartridges, and the other end cavity of the third horizontal unit containing filter cartridges is connected with the lower cavity of the fourth vertical unit containing filter cartridges.

[0018] In some embodiments, it can be understood that the hydrolysis mixture from the third horizontal unit containing filter cartridges enters the lower cavity of the fourth vertical unit containing filter cartridges, and the volume of the lower cavity is greater than the cavity of the third horizontal unit containing filter cartridges, such as 1-10 times, and the lower cavity serves as a buffer zone to realize the oil-water separation of the hydrolysis mixture again.

[0019] The filter cartridges are selected from polyolefin special filter cartridges.

[0020] In the technical solution of the present application, the coalescer innovatively adopts a "Z" structure, and a single coalescer can accommodate four special filter cartridges, and the device volume utilization is high. The coalescer of the device adopts a "Z" structure, which can accommodate four-stage filter cartridges, maximally utilizes the device space, reduces the number of devices, and saves the device area. The "Z" structure has upper and lower settling zones, which facilitates the control of oil and water gravity settling separation.

[0021] The bottom of the cavity of the second vertical unit containing filter cartridges is connected to the hydrolyzate pipeline through a pipeline. Process water feeding pipes and / or return acid feeding pipes are arranged on the pipeline to form a device for cyclic separation and removal of chloride ions.

[0022] The device for reducing the acid value in the dimethyldichlorosilane hydrolysate separation and washing process comprises a plurality of agglomerator devices connected in series, and each agglomerator device has a substantially same structure as understood by those skilled in the art. In each agglomerator device, the bottom of the second vertical unit containing filter cores is connected to the hydrolysate discharge pipeline of the previous stage through a pipeline, and a process water feeding pipe and / or a return acid feeding pipe is arranged at the bottom of the second vertical unit containing filter cores in the last agglomerator device, thereby forming a device for removing chlorine ions through cyclic separation.

[0023] For example, the plurality of agglomerator devices are connected in series as three agglomerator devices. The bottom of the second vertical unit containing filter cores in the third agglomerator device is connected to the hydrolysate feeding pipeline of the second stage through a pipeline, and the bottom of the second vertical unit containing filter cores in the second agglomerator device is connected to the hydrolysate feeding pipeline of the first stage through a pipeline.

[0024] The liquid level at the bottom of the agglomerator is controlled by an interface meter to ensure that the acid-liquid interface at the bottom is not carried into the next stage agglomerator with the hydrolysate, thereby improving the agglomeration efficiency, stabilizing the process control, and ensuring uniform product quality. The pipeline mirrors and the mirrors on the equipment bodies between the processes can be used to directly observe the form of the dimethyldichlorosilane hydrolysate in the system, and the oil-water interface and the acid feeding flow rate can be adjusted in a timely manner.

[0025] Meanwhile, a process water feeding pipe and / or a return acid feeding pipe is arranged at the bottom of the second vertical unit containing filter cores in the third agglomerator device and connected to the hydrolysate discharge pipeline of the second stage through a pipeline, thereby forming a device for removing chlorine ions through cyclic separation.

[0026] The acid hydrolysate in the first horizontal unit containing filter cores and the third horizontal unit containing filter cores is fed into the filter cores and discharged from the outside of the filter cores.

[0027] The acid hydrolysate in the second vertical unit containing filter cores and the fourth vertical unit containing filter cores is fed from the outside of the filter cores and discharged from the inside of the filter cores.

[0028] The first horizontal unit containing filter cores and the third horizontal unit containing filter cores are provided with differential pressure transmitters at the front end and the rear end, and the pre-filter is also provided with differential pressure transmitters before and after the pre-filter, so that the equipment can be directly judged and switched at any time, and the filter bag can be replaced, thereby providing a guarantee for the stable operation of the entire oil-water separation device.

[0029] For the above device, the application also provides a method for reducing the acid value of dimethyldichlorosilane hydrolysate in the separation and washing process of the hydrolysate, which adopts coalescence liquid-liquid separation technology, and the hydrolysate of the device is sequentially washed by process water from back to front, and the water phase that is precipitated is sequentially used to wash the hydrolysate from front to back. The process performed by using the device includes the following steps:

[0030] The dimethyldichlorosilane hydrolysate and the water phase enter the static mixer, are fully mixed, then enter the pre-filter for filtration, and then enter the coalescer, which is first washed and coalesced by the first horizontal unit containing a filter core, and then the hydrolysate is repeatedly coalesced and separated by the second vertical unit containing a filter core. The separated water phase is collected at the lower cavity of the first horizontal unit containing a filter core and the second vertical unit containing a filter core, and is transported to the previous coalescer for washing by a delivery pump. The hydrolysate separated by the second filter core continues to enter the third and fourth filter cores for coalescence and separation. The separated water phase is collected at the lower cavity of the third horizontal unit containing a filter core and the fourth vertical unit containing a filter core, and the hydrolysate separated by the fourth filter core flows out of the device from the top outlet of the coalescer to obtain purified dimethyldichlorosilane hydrolysate.

[0031] The acid value of the dimethyldichlorosilane acidic hydrolysate before entering the coalescer is about 0.15-0.5%.

[0032] When the coalescer device is connected in series as a multi-stage coalescer device, the purified dimethyldichlorosilane hydrolysate is mixed with the water phase (the water phase here includes return acid, process water and circulating dilute acid) again and then enters the next-stage coalescer device, specifically enters the static mixer in the next-stage coalescer device, and is coalesced and separated again to obtain purified dimethyldichlorosilane hydrolysate again. The mixing and coalescence and separation process of the purified dimethyldichlorosilane hydrolysate and the water phase is repeated to realize the coalescence liquid-liquid separation technology.

[0033] When the coalescer device is connected in series as a three-stage coalescer device, process water is pumped from the inlet of the third-stage coalescer device. After a certain liquid level is formed at the bottom of the connection between the first filter core and the second filter core of the third-stage coalescer, a third-stage circulating pump is started to supply water to the second-stage coalescer. After a certain liquid level is formed at the bottom of the connection between the first filter core and the second filter core of the second-stage coalescer, a second-stage circulating pump is started to supply water to the first-stage coalescer. After a certain liquid level is formed at the bottom of the connection between the first filter core and the second filter core of the first-stage coalescer, a first-stage circulating pump is started to supply water to the front-end system for dimethyl reaction. The dimethyldichlorosilane acidic hydrolysate produced by the reaction is filtered by a pre-filter, enters the coalescer for multiple oil-water separation, and the hydrolysate from the coalescer is sequentially treated in the second-stage and third-stage coalescer devices to obtain purified dimethyldichlorosilane hydrolysate.

[0034] The volume ratio of the process water supplement to the dimethyl is 0.2-0.3:1.

[0035] The pressure difference of the pre-filter is less than 50 KPa, and the pressure difference of the first and third filters with filter cartridges is less than 100 KPa.

[0036] After the separation and washing are performed by using the method, the acid value of the hydrolysate is less than 10 ppm, further preferably less than 5 ppm, and further preferably less than 1 ppm.

[0037] In the technical solution of the present application, first, the liquid level at the bottom of the coalescer is controlled by using the interface meter, so that the acid liquid interface at the bottom is sufficient and cannot be entrained into the lower coalescer with the hydrolysate, the coalescing efficiency is improved, the process control is stable, and the product quality is uniform.

[0038] By calculating the height of the interface meter matching the current feed flow and the five-ring water supplement flow, the residence time of the hydrolysis product is regulated, the product quality is more stable, second, the pressure differences before and after the filters and the filter cartridges of the coalescer are observed, the filters are switched and the filter bags are replaced in time, so that impurities are prevented from being entrained into the equipment and causing the filter cartridges to be blocked and damaged, third, the sight glasses of the equipment and the pipelines are observed, the current state of the hydrolysis product is judged according to the color and form of the current hydrolysis product, and the reaction interface, water supplement and other parameters are adjusted in time.

[0039] The test results show that after the three-stage coalescer treatment, the acid value can be reduced to 70% of the raw material liquid, after the four-stage coalescer treatment, the acid value can be reduced to 90-98%, and after the five-stage coalescer treatment, the acid value can be reduced to 98-99.99%. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 It is a structure schematic diagram of the first-stage coalescer device, wherein the hydrolysate pipeline 1, the static mixer 2, the pre-filter 3, the coalescer 4, the first filter cartridge-containing horizontal unit 4-1, the second filter cartridge-containing vertical unit 4-2, the third filter cartridge-containing horizontal unit 4-3, the fourth filter cartridge-containing vertical unit 4-4, the liquid level meter 5, the pressure difference table 6, a is process water, b is acidic hydrolysate, c is finished hydrolysate, and d is dilute acid (or referred to as acid discharge). The shadow part is the filter cartridge installation position.

[0041] Figure 2 It is a structure schematic diagram of the three-stage coalescer device. DETAILED DESCRIPTION

[0042] Example 1

[0043] A device for reducing the acid value of dimethyl dichlorosilane hydrolysate in a separation and washing process, the device comprising a first-stage coalescer device, such as Figure 1As shown, the hydrolysate pipeline 1 in the concentrator device is connected with the static mixer 2, the static mixer 2 is connected with the pre-filter 3, the pre-filter 3 is connected with the coalescer 4, and the coalescer 4 is connected to the clean hydrolysate product area.

[0044] The first filter-containing horizontal unit 4-1 is connected with the lower part of the second filter-containing vertical unit 4-2, the upper part of the second filter-containing vertical unit 4-2 is connected with the third filter-containing horizontal unit 4-3, and the third filter-containing horizontal unit 4-3 is connected with the lower part of the fourth filter-containing vertical unit 4-4.

[0045] The filter cartridges in the first filter-containing horizontal unit 4-1 are arranged in the middle part of the first filter-containing horizontal unit 4-1, and cavities are formed at both ends of the first filter-containing horizontal unit 4-1.

[0046] The filter cartridges in the second filter-containing vertical unit 4-2 are arranged in the middle part of the second filter-containing vertical unit 4-2, and cavities are formed at both ends of the second filter-containing vertical unit 4-2.

[0047] The first filter-containing horizontal unit 4-1 is connected with the lower end cavity of the second filter-containing vertical unit 4-2, and the length of the second filter-containing vertical unit 4-2 is greater than that of the first filter-containing horizontal unit 4-1.

[0048] The filter cartridges in the third filter-containing horizontal unit 4-3 are arranged in the middle part of the third filter-containing horizontal unit 4-3, and cavities are formed at both ends of the third filter-containing horizontal unit 4-3; one end cavity is connected with the upper end cavity of the second filter-containing vertical unit 4-2, and the other end cavity is connected with the fourth filter-containing vertical unit 4-4.

[0049] The filter cartridges in the fourth filter-containing vertical unit 4-4 are arranged in the upper part of the fourth filter-containing vertical unit 4-4, and a cavity is formed in the lower part of the fourth filter-containing vertical unit 4-4; the other end cavity of the third filter-containing horizontal unit 4-3 is connected with the lower cavity of the fourth filter-containing vertical unit 4-4.

[0050] The filter cartridges are selected from the modified polyvinylidene fluoride filter cartridges of Pall Corporation.

[0051] The bottom of the second filter-containing vertical unit 4-2 is connected to the hydrolysate pipeline 1 through a pipeline;

[0052] A process water feeding pipe and / or a return acid feeding pipe are arranged on the pipeline to form a device for circular separation and removal of chlorine ions.

[0053] The front end and the rear end of the first filter core containing transverse unit 4-1, the second filter core containing vertical unit 4-2, the third filter core containing transverse unit 4-3 and the fourth filter core containing vertical unit 4-4 are provided with differential pressure transmitters.

[0054] Embodiment 2

[0055] A device for reducing the acid value of hydrolysate in the separation and washing process of dimethyl dichlorosilane hydrolysate, the device comprising a three-stage coalescer device, as shown in Figure 2 The coalescer device comprises a hydrolysate pipeline 1 connected with a static mixer 2, the static mixer 2 is connected with a pre-filter 3, the pre-filter 3 is connected with a coalescer 4, and the coalescer 4 is connected to a clean hydrolysate product area.

[0056] The coalescer 4 is connected with the lower part of the first filter core containing transverse unit 4-1 and the second filter core containing vertical unit 4-2, the upper part of the second filter core containing vertical unit 4-2 is connected with the third filter core containing transverse unit 4-3, and the lower part of the third filter core containing transverse unit 4-3 is connected with the fourth filter core containing vertical unit 4-4.

[0057] The filter core in the first filter core containing transverse unit 4-1 is arranged in the middle of the first filter core containing transverse unit 4-1, and cavities are formed at both ends of the first filter core containing transverse unit 4-1.

[0058] The filter core in the second filter core containing vertical unit 4-2 is arranged in the middle of the second filter core containing vertical unit 4-2, and cavities are formed at both ends of the second filter core containing vertical unit 4-2.

[0059] The lower end cavities of the first filter core containing transverse unit 4-1 and the second filter core containing vertical unit 4-2 are connected, and the length of the second filter core containing vertical unit 4-2 is greater than that of the first filter core containing transverse unit 4-1.

[0060] The filter core in the third filter core containing transverse unit 4-3 is arranged in the middle of the third filter core containing transverse unit 4-3, and cavities are formed at both ends of the third filter core containing transverse unit 4-3; one end cavity is connected with the upper end cavity of the second filter core containing vertical unit 4-2, and the other end cavity is connected with the fourth filter core containing vertical unit 4-4.

[0061] The filter core in the fourth filter core containing vertical unit 4-4 is arranged in the upper part of the fourth filter core containing vertical unit 4-4, and a cavity is formed in the lower part of the fourth filter core containing vertical unit 4-4, and the other end cavity of the third filter core containing transverse unit 4-3 is connected with the lower cavity of the fourth filter core containing vertical unit 4-4.

[0062] The filter core is made of modified PVDF.

[0063] The overall structure of the above-mentioned primary concentrator device is connected in series with a secondary concentrator device, which is connected in series with a tertiary concentrator device, wherein the primary concentrator device, the secondary concentrator device, and the tertiary concentrator device contain the same structural components.

[0064] The fourth filter-containing vertical unit in the primary concentrator device is connected to a static mixer in the secondary concentrator device to form a connection; the fourth filter-containing vertical unit in the secondary concentrator device is connected to a static mixer in the tertiary concentrator device to form a connection, and the fourth filter-containing vertical unit in the tertiary concentrator device is connected to a static mixer at the top to obtain clean hydrolysate; thus forming a series connection.

[0065] The second filter-containing vertical unit in the tertiary concentrator device is connected to a static mixer in the tertiary concentrator device through a pipeline to form a return circulation; the second filter-containing vertical unit in the secondary concentrator device is connected to a static mixer in the secondary concentrator device through a pipeline to form a return circulation; and the second filter-containing vertical unit in the primary concentrator device is connected to a static mixer in the primary concentrator device through a pipeline to form a return circulation.

[0066] It is obvious to those skilled in the art that a circulating pump is connected to the pipeline.

[0067] Example 3

[0068] A method for reducing the acid value in the separation and washing process of dimethyldichlorosilane hydrolysate, the device of Example 2 is used to carry out the following process:

[0069] After pumping process water into the tertiary concentrator device to fill the equipment, start the tertiary circulating pump to circulate the water, and at the same time, start returning water to the secondary concentrator device, when the secondary concentrator device is filled, return water to the primary concentrator device, and when the primary concentrator device is filled, pump in acidic dimethyldichlorosilane hydrolysate, mix it with the returned water in the secondary concentrator device at a volume ratio of 3:1, and then enter the two-stage static mixer in series for thorough mixing and extraction. After extraction, filter through a pre-filter, and then enter the concentrator for multiple oil-water separation. The hydrolysate from the concentrator is then sequentially processed in the secondary concentrator device and the tertiary concentrator device, and when it reaches the inlet of the static mixer in the tertiary concentrator device, it is mixed with process water from outside and its own circulating acid to enter the oil-water separation device, and the chlorine ion content in the outgoing hydrolysate is greatly reduced.

[0070] In the above-mentioned primary coalescer device, secondary coalescer device, and tertiary coalescer device, the hydrolyzate discharged from the premixer is first subjected to oil-water separation by the first horizontal unit containing filter cartridges, and the acid deposited at the bottom is pumped to the previous process. The hydrolyzate passes upward through the second vertical unit containing filter cartridges to repeat the oil-acid separation process. The hydrolyzate after passing through the vertical filter cartridges reaches the top of the coalescer, and is subjected to coalescence and oil-water separation by the third horizontal unit containing filter cartridges at the top and the fourth vertical unit containing filter cartridges at the top. The mixture passes through the four filter cartridges for coalescence and separation, flows out of the device from the coalescer outlet, and obtains purified dimethyldichlorosilane hydrolyzate. Each special filter cartridge of the coalescer is provided with a front-rear differential pressure transmitter, and the pre-filter is also provided with a pressure gauge before and after it.

[0071] After separation and washing by the method, the chloride ion content after treatment by the primary coalescer device is 500-1000 PPM; the chloride ion content after treatment by the secondary coalescer device is 50-100 PPM; and the chloride ion content after treatment by the tertiary coalescer device is 5 ppm.

Claims

1. A system for reducing the hydrolyzate acid value in a dimethyldichlorosilane hydrolyzate separation wash process, characterized by, The device comprises at least one stage of the agglomerator device, the agglomerator device comprises a hydrolysate feeding pipe (1) connected with a static mixer (2), the static mixer (2) is connected with a pre-filter (3), the pre-filter (3) is connected with a coalescer (4), and the coalescer (4) is connected to a finished hydrolysate product area. The coalescer (4) forms cavities at both ends of a first filter-cartridge-containing horizontal unit (4-1), forms cavities at both upper and lower ends of a second filter-cartridge-containing vertical unit (4-2), forms cavities at both ends of a third filter-cartridge-containing horizontal unit (4-3), and forms a cavity at the lower end of a fourth filter-cartridge-containing vertical unit (4-4). The end cavity of the first filter-cartridge-containing horizontal unit (4-1) is connected with the lower end cavity of the second filter-cartridge-containing vertical unit (4-2). The end cavity of the third filter-cartridge-containing horizontal unit (4-3) is connected with the upper end cavity of the second filter-cartridge-containing vertical unit (4-2). The other end cavity of the third filter-cartridge-containing horizontal unit (4-3) is connected with the lower end cavity of the fourth filter-cartridge-containing vertical unit (4-4). The acid hydrolysate in the first filter-cartridge-containing horizontal unit (4-1) and the third filter-cartridge-containing horizontal unit (4-3) is fed in from the inside of the filter cartridges and fed out from the outside of the filter cartridges. The acid hydrolysate in the second filter-cartridge-containing vertical unit (4-2) and the fourth filter-cartridge-containing vertical unit (4-4) is fed in from the outside of the filter cartridges and fed out from the inside of the filter cartridges. The bottom of the second filter-cartridge-containing vertical unit (4-2) is connected to the hydrolysate feeding pipe (1) through a pipe, forming a device for recycling washing to reduce the acid value of the hydrolysate.

2. The system for reducing the hydrolyzate acid number in a dimethyldichlorosilane hydrolyzate separation wash process according to claim 1, characterized in that, The filter cartridges in the first filter-cartridge-containing horizontal unit (4-1) are arranged in the middle of the first filter-cartridge-containing horizontal unit (4-1).

3. The system for reducing the hydrolyzate acid number in a dimethyldichlorosilane hydrolyzate separation wash process of claim 2, wherein, The filter cartridges in the second filter-cartridge-containing vertical unit (4-2) are arranged in the middle of the second filter-cartridge-containing vertical unit (4-2).

4. The system for reducing the hydrolyzate acid value in a dimethyldichlorosilane hydrolyzate separation wash process of claim 3, wherein, The filter cartridges in the third filter-cartridge-containing horizontal unit (4-3) are arranged in the middle of the third filter-cartridge-containing horizontal unit (4-3).

5. The system for reducing the hydrolyzate acid value in a dimethyldichlorosilane hydrolyzate separation wash process of claim 4, wherein, The filter cartridges in the fourth filter-cartridge-containing vertical unit (4-4) are arranged at the upper end of the fourth filter-cartridge-containing vertical unit (4-4).

6. The system for reducing the hydrolyzate acid number in a dimethyldichlorosilane hydrolyzate separation wash process according to claim 1, wherein, When the device is a multi-stage agglomerator device, each stage of the agglomerator device is connected in series, and in each stage of the agglomerator device, the top of the fourth filter-cartridge-containing vertical unit is connected to the hydrolysate feeding pipe of the first filter-cartridge-containing horizontal unit of the next stage of the coalescer through a pipe, for conveying the acid hydrolysate.

7. The system for reducing the hydrolyzate acid number in a dimethyldichlorosilane hydrolyzate separation wash process according to claim 6, characterized in that, The bottom of the second filter-cartridge-containing vertical unit is connected to the hydrolysate feeding pipe of the previous stage of the coalescer through a pipe, for conveying dilute hydrochloric acid. The bottom of the second filter-cartridge-containing vertical unit in the last stage of the coalescer is connected to the hydrolysate feeding pipe of the previous stage through a pipe, and a process water feeding pipe is arranged, forming a device for recycling washing to reduce the acid value of the hydrolysate.

8. The system for reducing the hydrolyzate acid number in a dimethyldichlorosilane hydrolyzate separation wash process according to claim 7, characterized in that, The multi-stage agglomerator device is a three-stage agglomerator device connected in series.

9. The system for reducing the acid value of hydrolyzate in a dimethyldichlorosilane hydrolyzate separation wash process according to any one of claims 1-8, characterized in that, The front end and the rear end of the first filter-cartridge-containing horizontal unit (4-1) and the third filter-cartridge-containing horizontal unit (4-3) are each provided with a differential pressure transmitter.

10. A method for reducing the acid value of hydrolyzate in a dimethyldichlorosilane hydrolyzate separation wash process, characterized by, The process performed by the system of any one of claims 1-9 comprises the following steps: The dimethyl dichlorosiloxane hydrolysate and the water phase enter a static mixer, are mixed sufficiently, enter a pre-filter for filtration after mixing, enter a coalescer, are washed and coalesced by a first horizontal unit containing filter cartridges, and then the hydrolysate is repeatedly coalesced and separated upward through a second vertical unit containing filter cartridges, the separated water phase is collected at the lower end cavities of the first horizontal unit containing filter cartridges and the second vertical unit containing filter cartridges, and is delivered to a previous stage coalescer for washing by a delivery pump; the hydrolysate separated through the second vertical unit containing filter cartridges continues to enter a third horizontal unit containing filter cartridges and a fourth vertical unit containing filter cartridges for coalescing and separating, the separated water phase is collected at the lower end cavities of the third horizontal unit containing filter cartridges and the fourth vertical unit containing filter cartridges, the hydrolysate separated through the fourth vertical unit containing filter cartridges flows out of the device from the top outlet of the coalescer, and purified dimethyl dichlorosilane hydrolysate is obtained.

11. The method for reducing the hydrolyzate acid number in a dimethyldichlorosilane hydrolyzate separation wash process according to claim 10, characterized in that, The acid value of the dimethyl dichlorosilane acidic hydrolysate before entering the coalescer is 0.15-0.5%.

12. The method for reducing the hydrolyzate acid number in a dimethyldichlorosilane hydrolyzate separation wash process according to claim 11, characterized in that, When the coalescer device is connected in series as a multi-stage coalescer device, the purified dimethyl dichlorosilane hydrolysate is mixed with water phase again and enters the next stage coalescer device, is coalesced and separated again, and purified dimethyl dichlorosilane hydrolysate is obtained again; the water phase includes process water, circulating dilute acid, and coalesced dilute acid from a previous stage coalescer.

13. The method for reducing the hydrolyzate acid number in a dimethyldichlorosilane hydrolyzate separation wash process according to claim 12, characterized in that, When the coalescer device is connected in series as a three-stage coalescer device, process water is pumped into the inlet of the third stage coalescer device, the third stage circulating pump is started to supplement water to the second stage coalescer when there is a certain liquid level at the bottom of the connection between the first filter cartridge and the second filter cartridge of the third stage coalescer, the second stage circulating pump is started to supplement water to the first stage coalescer when there is a certain liquid level at the bottom of the connection between the first filter cartridge and the second filter cartridge of the second stage coalescer, and the first stage circulating pump is started to supplement water to the front-end system for reaction with dimethyl dichlorosilane when there is a certain liquid level at the bottom of the connection between the first filter cartridge and the second filter cartridge of the first stage coalescer, the dimethyl dichlorosilane acidic hydrolysate produced by the reaction is filtered by a pre-filter, enters the coalescer for multiple oil-water separation, and the hydrolysate from the coalescer is sequentially treated in the second stage and third stage coalescer devices to obtain purified dimethyl dichlorosilane hydrolysate.

14. The method for reducing hydrolyzate acid number in a dimethyldichlorosilane hydrolyzate separation wash process according to claim 10, wherein, The volume ratio of the process water supplementing amount of the third stage coalescer device to dimethyl dichlorosilane is 0.2-0.3:

1.

15. The method for reducing hydrolyzate acid number in a dimethyldichlorosilane hydrolyzate separation wash process according to claim 10, wherein, The pressure difference of the pre-filter is less than 50 KPa, and the pressure difference of the first filter cartridge and the third filter cartridge is less than 100 KPa.

16. The method for reducing the acid value of hydrolyzate in a dimethyldichlorosilane hydrolyzate separation wash process according to any one of claims 10-15, characterized in that, After separation and washing by the method, the acid value of the hydrolysate is less than 10 ppm.

17. The method for reducing hydrolyzate acid number in a dimethyldichlorosilane hydrolyzate separation wash process according to claim 16, characterized in that, After separation and washing by the method, the acid value of the hydrolysate is less than 5 ppm.

18. The method for reducing hydrolyzate acid number in a dimethyldichlorosilane hydrolyzate separation wash process according to claim 16, characterized in that, After separation and washing by the method, the acid value of the hydrolysate is less than 1 ppm.

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