CN211988610U

CN211988610U - PH adjusting device

Info

Publication number: CN211988610U
Application number: CN202020229448.1U
Authority: CN
Inventors: 杨韶辉; 王宇婷; 张明晖
Original assignee: Shanghai Gengcai New Material Technology Co ltd
Current assignee: Shanghai Gengcai New Material Technology Co ltd
Priority date: 2020-02-29
Filing date: 2020-02-29
Publication date: 2020-11-24
Anticipated expiration: 2030-02-28

Abstract

The utility model relates to a pH adjusting device, adjusting device including become salt cauldron (3) and respectively with become amine pH adjusting tank (1) and sour pH adjusting tank (2) of salt cauldron (3) intercommunication, be equipped with pH meter (301) on becoming salt cauldron (3), be equipped with first valve (101) on amine pH adjusting tank (1), sour pH adjusting tank (2) are equipped with second valve (201), pH meter (301) are connected with pH control box (7) to be connected with first valve (101) and second valve (201) electricity respectively through pH control box (7). Compared with the prior art, the utility model discloses can accurately realize the salified pH of nylon fast and adjust, can realize the stability of nylon salt moreover to very big improvement production efficiency, improved the stability of final product.

Description

PH adjusting device

Technical Field

The utility model relates to a belong to nylon polymerization equipment technical field, concretely relates to pH adjusting device.

Background

Polyamide (commonly known as nylon) has excellent mechanical strength, wear resistance, self-lubricating property and better corrosion resistance, is widely applied to the fields of electronic and electric appliances, automobile industry, engineering machinery, fibers and the like, is one of five important engineering plastics, and has the first yield of the five engineering plastics.

The polyamide is obtained by condensation polymerization of diamine and diacid, in the synthesis process, in order to ensure the equivalent ratio of the diamine and the diacid in the reaction process, salt formation of the diamine and the diacid is carried out firstly, and the equivalent ratio of the salt formation reaction is realized by adjusting the pH value of a salt solution. How to quickly and accurately adjust the pH is always a difficult problem in industrial production, and the pH stability of each batch of salt solution also determines the stability of each batch of nylon products, so the pH adjustment is very important for industrial production of nylon.

Patent CN104130131 discloses a continuous process for producing solutions of nylon salts prepared using a liquid partially equilibrated acid solution enriched in dicarboxylic acids, in particular adipic acid. Preparing a liquid feed by metering dicarboxylic acid powder on a weight basis from a loss-in-weight feeder to a feed conduit that delivers the dicarboxylic acid powder to an in-line disperser; feeding a first feed stream of diamine into an in-line disperser to form a dispersion comprising between 32 and 46 weight percent dicarboxylic acid, between 11 and 15 weight percent diamine, and 39 and 57 weight percent water, and heating the dispersion at a temperature between 50 and 60 ℃ to form a partially equilibrated acid solution, preparing a nylon salt solution from the liquid partially equilibrated acid solution, and continuously passing into a storage tank. The method has complex equipment and a plurality of control points, and the solubility of water to long-chain carboxylic acid, long-chain amine and aromatic carboxylic acid is limited, so that the quality control of the nylon salt of the monomer is very difficult.

Patent CN206783572U discloses a salifying system for producing nylon 66 saline solution, which comprises a pure water tank and an amine storage tank, wherein an amine circulating pipeline of the amine storage tank is provided with an amine circulating pump, the pure water circulating pipeline of the pure water tank is provided with a water circulating pump, the amine storage tank is connected with a first reactor through a pipeline, the first reactor is provided with an acid feeding pipeline and a material circulating pipeline, the material circulating pipeline is provided with a circulating pump, pH value detectors are arranged on pH value detection pipelines of the first reactor and a second reactor, a discharge pipeline is arranged between the first reactor and a heat exchanger, the heat exchanger is connected with the second reactor through a pipeline, and the second reactor is connected with a continuous nylon salt solution tank; a water outlet pipe is arranged between the pure water tank and the second reactor, an amine feeding pipeline is arranged between the amine storage tank and the second reactor, and a branch discharging pipeline on the discharging pipeline is connected with the second reactor. The method adopts water to adjust the concentration of the materials in the second reactor, adopts amine to adjust the pH value of the materials in the second reactor, has complex adjusting device and more control points, and only uses hexamethylene diamine for amine adjustment, but can not be used for salifying and adjusting the pH value of decamethylene diamine, dodecamethylene diamine, p-xylylenediamine and the like which have high melting points and are solid at normal temperature.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a pH adjusting device for solving above-mentioned problem, can accurately realize the salified pH of nylon and adjust fast, can realize the stability of nylon salt moreover to very big improvement production efficiency, improved the stability of final product.

The purpose of the utility model is realized through the following technical scheme:

the utility model provides a pH adjusting device, adjusting device is including becoming the salt cauldron and respectively with amine pH adjusting tank and the sour pH adjusting tank of salifying cauldron intercommunication, be equipped with the pH meter on the salifying cauldron, be equipped with first valve on the amine pH adjusting tank, sour pH adjusting tank is equipped with the second valve, the pH meter is connected with the pH control box to be connected with first valve and second valve electricity respectively through the pH control box. According to the measurement result of the pH meter, the first valve or the second valve is selectively opened through the pH control box, and the pH value of the salt solution in the salt kettle is adjusted, so that the aim of ensuring the equivalent ratio of the diamine and the dibasic acid in the reaction process is fulfilled. And a pH signal transmission line is arranged between the pH meter and the pH control box, and a control signal transmission line is arranged between the pH control box and the first valve and between the pH meter and the pH control box and between the pH control box and the second valve. Wherein, the pH meter adopts high accuracy industry on-line pH meter, and first valve and second valve are electronic little flow control valve. The pH value of the salt solution in the salifying kettle is measured in real time by a high-precision industrial online pH meter, a pH value signal is transmitted to a pH control box through a pH signal transmission line, the pH control box finishes displaying and control adjusting, and a control adjusting signal is transmitted to a first valve or a second valve through a control signal transmission line to adjust the on-off of the valves, so that the input amount of amine or acid is adjusted.

Further, amine pH adjusting tank includes the first jar of body, locates the first upper cover of the first jar of body upside and locates the first low head of the first jar of body downside, the internal first agitating unit that is equipped with of first jar, the first jar of external side is equipped with steam jacket, be equipped with amine material entry on the first upper cover, be equipped with amine material export on the first low head, first valve is located on the first low head, controls opening of amine material export. The amine material is added from an amine material inlet and comprises amine and a solvent, the amine refers to aliphatic diamine containing 4-18 carbon atoms on a main chain, p-xylylenediamine, m-xylylenediamine, cyclohexanediamine and the like, and some amines are solid and blocky at normal temperature, so that the amines need to be heated to be in a liquid state to prevent blockage, a steam jacket is used for ensuring that the high-melting-point amine can be melted into a liquid state, and a first stirring device can fully mix the amine and the solvent and ensure uniform heat transfer.

Furthermore, a steam inlet and a steam outlet are arranged on the steam jacket, a steam system is arranged between the steam inlet and the steam outlet, and the steam system comprises a steam generating furnace, a control valve, a circulating pump and a communicating pipeline which communicates the steam generating furnace, the control valve, the circulating pump, the steam inlet and the steam outlet. When the steam is not needed, the control valve is closed, when the temperature of the steam is not high enough or the amount of the steam is not enough, the steam generating furnace is heated, and the circulating pump can circulate the steam.

Further, the height of the steam inlet is greater than the height of the steam outlet. The steam inlet and outlet follow a high in-out-low out principle, allowing for better and faster melting of the amine.

Furthermore, be equipped with first nitrogen gas entry and first nitrogen gas export on the first upper cover, all be equipped with the valve on first nitrogen gas entry and the first nitrogen gas export for control lets in and emits nitrogen gas. Because amine is easily oxidized at high temperature and the salt formed by amine and acid is also easily oxidized at high temperature, in order to avoid amine oxidation and air from being brought into a salt forming kettle, nitrogen replacement needs to be carried out on the amine pH adjusting tank before heating, and the valves of the first nitrogen inlet and the first nitrogen outlet need to be opened in the nitrogen replacement process.

Furthermore, be equipped with first manometer on the first upper cover, be equipped with first level gauge and temperature measuring instrument on the first jar of body. The first pressure gauge monitors the pressure of the amine pH adjusting tank in real time, the design pressure of the amine pH adjusting tank is 0.1-2MPa, and overpressure in the first tank body is prevented. The first liquid level meter is a membrane liquid level meter sold in the market and is realized by pressure difference, and the membrane liquid level meter has the advantages of high response speed, high precision, good overload performance, small volume and light weight. The temperature measuring instrument is arranged on the lower side of the first tank body, so that the real temperature of the amine material can be conveniently measured, and the commercially available bimetal temperature measuring instrument can be used for directly measuring the temperature of liquid and gas in the range of-80 ℃ to 500 ℃ in various production processes, is safe and reliable, can directly read temperature readings, and is convenient and rapid.

Further, sour pH adjusts jar includes the second jar of body, locates the second upper cover of the second jar of body upside and locates the second low head of the second jar of body downside, the internal second agitating unit that is equipped with of second jar, be equipped with sour material entry on the second upper cover, be equipped with sour material export on the second low head, the second valve is located on the second low head, controls opening of sour material export. The acid material comprising acid and solvent is added from the acid material inlet, the acid refers to aliphatic dibasic acid containing 4-18 carbon atoms on the main chain, terephthalic acid, isophthalic acid, cyclohexanedicarboxylic acid and the like, and the acid is powdery, so that the acid can form suspension after the second stirring device is started, the acid and the solvent are fully mixed, and the feeding is convenient.

And furthermore, a second nitrogen inlet and a second nitrogen outlet are formed in the second upper sealing head, and valves are arranged on the second nitrogen inlet and the second nitrogen outlet and used for controlling the introduction and the discharge of nitrogen. Because the salt formed by amine and acid is easy to oxidize at high temperature, in order to prevent air from being brought into the salt forming kettle, nitrogen gas replacement needs to be carried out on the acid pH adjusting tank before the acid is added into the salt forming kettle, valves of a second nitrogen gas inlet and a second nitrogen gas outlet need to be opened in the nitrogen gas replacement process, and in addition, nitrogen gas needs to be introduced through the second nitrogen gas inlet when the acid pH adjusting tank is pressurized in the later period.

Furthermore, a second pressure gauge is arranged on the second upper end socket, and a second liquid level meter is arranged on the second tank body. And the second pressure gauge monitors the pressure of the acid pH adjusting tank in real time, the design pressure of the acid pH adjusting tank is 0.1-2MPa, and overpressure in the second tank body is prevented. The second liquid level meter is a diaphragm liquid level meter sold in the market and is realized by pressure difference, and the diaphragm liquid level meter has the advantages of high response speed, high precision, good overload performance, small volume and light weight. The amount of acid materials in the acid pH adjusting tank can be accurately seen through the liquid level meter, and the acid materials are properly added according to the conditions.

Further, the salification kettle comprises a third kettle body, a third upper end socket and a third lower end socket, the third upper end socket is arranged on the upper side of the third kettle body, the third lower end socket is arranged on the lower side of the third kettle body, a third stirring device is arranged in the third kettle body, a salification kettle amine material inlet and a salification kettle acid material inlet are formed in the third upper end socket, a salification kettle salt material outlet is formed in the third lower end socket, a pH meter is arranged in the third kettle body, a first amine pipeline is arranged between the salification kettle amine material inlet and the amine material outlet and communicated with the salification kettle amine material inlet through the first amine pipeline, and a second acid pipeline is arranged between the salification kettle acid material inlet and the acid material outlet and communicated with the salification kettle acid material inlet through. The pH meter is inserted into the salt forming kettle from an opening on the kettle wall in the middle of the salt forming kettle, and the design pressure of the salt forming kettle is 0.1-2 MPa. More specifically, the salt formation kettle further comprises a solvent charging port, a pressure gauge, a temperature measuring instrument, a nitrogen inlet, a nitrogen outlet, a liquid level meter, a steam jacket, a manhole and the like, and the arrangement of the components is described and illustrated in detail with reference to the existing salt formation kettle.

Further, the first stirring device, the second stirring device and the third stirring device respectively comprise a stirring shaft and a stirring paddle connected with the stirring shaft. The stirring speed and the stirring time can be controlled by the stirring shaft, and the stirring paddle comprises a plurality of stirring blades.

In polyamide's salification reaction, just can regard diamine and dibasic acid to reach when the pH of salt solution reaches specified numerical value and equallized than, the utility model discloses an adjusting device adds amine or acidification to the salification cauldron according to the pH of salt solution in the salification cauldron, makes the pH fluctuation of salt solution little.

The working process of the amine pH adjusting tank is as follows: amine and a solvent are respectively added into an amine PH regulating tank from an amine material inlet; introducing nitrogen from the first nitrogen inlet, standing for 1min, discharging nitrogen from the first nitrogen outlet, and repeating for 3 times; opening the first stirring device, introducing steam into a steam inlet to heat the amine pH adjusting tank, and refluxing the reflux steam out through a steam outlet; when the temperature is displayed by the temperature measuring instrument to reach the set temperature, nitrogen is introduced into the amine pH adjusting tank through the first nitrogen inlet, when the pressure is displayed by the first pressure gauge to reach the set pressure, the amine material outlet is opened, the amine material is added into the salt forming kettle, and when the pH value of the salt solution measured by the pH meter in the salt forming kettle reaches the set value range, the amine material outlet is automatically closed through the pH control box; and after the salt-forming kettle is continuously stirred for 10 minutes, if the pH value is smaller than the set pH range, automatically opening an amine material outlet through a pH control box, repeating the operations until the pH value of the salt solution measured by the pH meter reaches the set value range, and finishing salt forming.

The working process of the acid pH adjusting tank is as follows: respectively adding acid and a solvent into an acid pH adjusting tank from an acid material inlet; introducing nitrogen from a second nitrogen inlet, standing for 1min, discharging nitrogen from a second nitrogen outlet, and repeating for 3 times; opening a second stirring device, introducing nitrogen into the acid pH adjusting tank through a second nitrogen inlet, opening an acid material outlet when a second pressure gauge displays that the pressure reaches a set pressure, adding the acid material into the salt forming kettle, and automatically closing the acid material outlet through a pH control box when the pH of the salt solution measured by a pH meter in the salt forming kettle reaches a set value range; and after the salt-forming kettle is continuously stirred for 10 minutes, if the pH value is larger than the set pH range, automatically opening an acid material outlet through a pH control box, repeating the operations until the pH value of the salt solution measured by the pH meter reaches the set value range, and finishing salt forming.

Utilize the pH when this device can the automatically regulated salify, when being less than preset value as salt cauldron pH, amine pH adjusting tank opens first valve and carries out pH regulation to the salt solution, when being greater than preset value as salt cauldron pH, acid pH adjusting tank opens the second valve and carries out pH regulation to the salt solution. Compared with the prior art, the utility model discloses the difference of salt between batches that has reduced because of human intervention produces to improve the stability of product, quick adjustment pH has also improved production efficiency, has practiced thrift manufacturing cost, has improved the overall efficiency of enterprise.

Drawings

FIG. 1 is a schematic view of a pH adjusting apparatus;

FIG. 2 is a schematic diagram of the structure of an amine pH adjustment tank;

FIG. 3 is a schematic diagram of the structure of an acid pH adjustment tank;

FIG. 4 is a schematic structural diagram of a salt forming kettle;

FIG. 5 is a schematic view of a steam system;

FIG. 6 is a schematic diagram of the pH automatic adjustment control.

In the figure: 1-amine pH adjusting tank; 101-a first valve; 102-a first tank; 103-a first upper end enclosure; 104-a first lower end enclosure; 105-a first stirring device; 106-steam jacket; a 107-amine feed inlet; a 108-amine material outlet; 109-a steam outlet; 110-a steam inlet; 111-a first nitrogen inlet; 112-a first nitrogen outlet; 113-a first pressure gauge; 114-a first level gauge; 115-temperature measuring instrument; 2-acid pH adjusting tank; 201-a second valve; 202-a second tank; 203-a second upper end enclosure; 204-a second lower end enclosure; 205-a second stirring device; 206-acid feed inlet; 207-acid material outlet; 208-a second nitrogen inlet; 209-a second nitrogen outlet; 210-a second pressure gauge; 211-a second level gauge; 3-a salt forming kettle; 301-pH meter; 302-a third kettle body; 303-a third upper end enclosure; 304-a third lower head; 305-a third stirring device; 306-amine material inlet of salt-forming kettle; 307-salt-forming kettle acid material inlet; 308-salt material outlet of the salt forming kettle; 4-a steam system; 401-steam generating furnace; 402-a control valve; 403-a circulation pump; 404-connecting the pipes; 5-a first amine conduit; 6-a second acid conduit; 7-pH control box; 8-pH signal transmission line; 9-control signal transmission line.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Examples

As shown in fig. 1, a pH adjusting device, adjusting device includes salt forming kettle 3 and amine pH adjusting tank 1 and acid pH adjusting tank 2 respectively communicated with salt forming kettle 3, last pH meter 301 that is equipped with of salt forming kettle 3, be equipped with first valve 101 on amine pH adjusting tank 1, acid pH adjusting tank 2 is equipped with second valve 201, pH meter 301 is connected with pH control box 7 through pH signal transmission line 8, and be connected with first valve 101 and second valve 201 electricity respectively through pH control box 7, pH control box 7 is connected with first valve 101 and second valve 201 respectively through control signal transmission line 9, it is specifically as shown in fig. 6.

As shown in fig. 2, the amine pH adjusting tank 1 includes a first tank 102, a first upper head 103 disposed on an upper side of the first tank 102, and a first lower head 104 disposed on a lower side of the first tank 102, a first stirring device 105 is disposed in the first tank 102, a steam jacket 106 is disposed on an outer side of the first tank 102, an amine material inlet 107, a first nitrogen inlet 111, a first nitrogen outlet 112, and a first pressure gauge 113 are disposed on the first upper head 103, valves are disposed on the first nitrogen inlet 111 and the first nitrogen outlet 112, a first liquid level meter 114 and a temperature measuring instrument 115 are disposed on the first tank 102, an amine material outlet 108 is disposed on the first lower head 104, and the first valve 101 is disposed on the first lower head 104 to control opening of the amine material outlet 108. The steam jacket 106 is provided with a steam outlet 109 and a steam inlet 110, the steam system 4 is arranged between the steam outlet 109 and the steam inlet 110, and the steam system 4 comprises a steam generating furnace 401, a control valve 402, a circulating pump 403 and a communication pipeline 404 for communicating the steam generating furnace 401, the control valve 402, the circulating pump 403, the steam outlet 109 and the steam inlet 110, as shown in fig. 5. The first stirring device 105 comprises a stirring shaft and a stirring paddle connected with the stirring shaft, a stirring shaft through hole for the penetration of the stirring shaft is formed in the first upper end enclosure 103, and the stirring paddle is located in the first tank 102.

As shown in fig. 3, the acid pH adjusting tank 2 includes a second tank 202, a second upper head 203 disposed on the upper side of the second tank 202, and a second lower head 204 disposed on the lower side of the second tank 202, a second stirring device 205 is disposed in the second tank 202, the second upper head 203 is provided with an acid material inlet 206, a second nitrogen gas inlet 208, a second nitrogen gas outlet 209, and a second pressure gauge 210, valves are disposed on the second nitrogen gas inlet 208 and the second nitrogen gas outlet 209, the second tank 202 is provided with a second liquid level meter 211, the second lower head 204 is provided with an acid material outlet 207, and the second valve 201 is disposed on the second lower head 204 to control the opening of the acid material outlet 207. The second stirring device 205 comprises a stirring shaft and a stirring paddle connected with the stirring shaft, a stirring shaft through hole for the penetration of the stirring shaft is arranged on the second upper sealing head 203, and the stirring paddle is positioned in the first tank 202.

As shown in fig. 4, the salt formation kettle 3 includes a third kettle body 302, a third upper end enclosure 303 disposed on the upper side of the third kettle body 302, and a third lower end enclosure 304 disposed on the lower side of the third kettle body 302, a third stirring device 305 is disposed in the third kettle body 302, a salt formation kettle amine material inlet 306 and a salt formation kettle acid material inlet 307 are disposed on the third upper end enclosure 303, a salt formation kettle salt material outlet 308 is disposed on the third lower end enclosure 304, a pH meter 301 is disposed in the third kettle body 302, a first amine pipeline 5 is disposed between the salt formation kettle amine material inlet 306 and the amine material outlet 108 and is communicated with the salt formation kettle amine material inlet through the first amine pipeline 5, and a second acid pipeline 6 is disposed between the salt formation kettle acid material inlet 307 and the acid material outlet 207 and is communicated with the salt formation kettle acid material inlet through the. The third stirring device 305 includes a stirring shaft and a stirring paddle connected to the stirring shaft, a stirring shaft through hole for the stirring shaft to pass through is formed in the third upper seal head 303, and the stirring paddle is located in the third kettle body 302. The salt forming kettle 3 further comprises a solvent charging port, a pressure gauge, a temperature measuring instrument, a nitrogen inlet, a nitrogen outlet, a liquid level meter, a steam jacket, a manhole and the like, and the arrangement of the components is described and illustrated in detail with reference to the existing salt forming kettle.

The embodiments described above are intended to facilitate the understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention according to the disclosure of the present invention.

Claims

1. The utility model provides a pH adjusting device, its characterized in that, adjusting device is including becoming salt cauldron (3) and respectively with become amine pH adjusting tank (1) and sour pH adjusting tank (2) of salt cauldron (3) intercommunication, be equipped with pH meter (301) on becoming salt cauldron (3), be equipped with first valve (101) on amine pH adjusting tank (1), sour pH adjusting tank (2) are equipped with second valve (201), pH meter (301) are connected with pH control box (7) to be connected with first valve (101) and second valve (201) electricity respectively through pH control box (7).

2. The pH adjusting device according to claim 1, wherein the amine pH adjusting tank (1) comprises a first tank body (102), a first upper end enclosure (103) arranged on the upper side of the first tank body (102), and a first lower end enclosure (104) arranged on the lower side of the first tank body (102), a first stirring device (105) is arranged in the first tank body (102), a steam jacket (106) is arranged on the outer side of the first tank body (102), an amine material inlet (107) is arranged on the first upper end enclosure (103), an amine material outlet (108) is arranged on the first lower end enclosure (104), and the first valve (101) is arranged on the first lower end enclosure (104) to control the opening of the amine material outlet (108).

3. The pH adjusting device according to claim 2, wherein a steam inlet (110) and a steam outlet (109) are arranged on the steam jacket (106), a steam system (4) is arranged between the steam inlet (110) and the steam outlet (109), and the steam system (4) comprises a steam generating furnace (401), a control valve (402), a circulating pump (403) and a communication pipeline (404) for communicating the steam generating furnace (401), the control valve (402), the circulating pump (403), the steam inlet (110) and the steam outlet (109).

4. The pH adjusting device according to claim 2, wherein the first upper sealing head (103) is provided with a first nitrogen inlet (111) and a first nitrogen outlet (112).

5. The pH adjusting device according to claim 2, wherein a first pressure gauge (113) is arranged on the first upper sealing head (103), and a first liquid level gauge (114) and a temperature measuring instrument (115) are arranged on the first tank body (102).

6. The pH adjusting device according to claim 2, wherein the acid pH adjusting tank (2) comprises a second tank body (202), a second upper end enclosure (203) arranged on the upper side of the second tank body (202), and a second lower end enclosure (204) arranged on the lower side of the second tank body (202), a second stirring device (205) is arranged in the second tank body (202), an acid material inlet (206) is arranged on the second upper end enclosure (203), an acid material outlet (207) is arranged on the second lower end enclosure (204), and the second valve (201) is arranged on the second lower end enclosure (204) to control the opening of the acid material outlet (207).

7. The pH adjusting device of claim 6, wherein the second upper sealing head (203) is provided with a second nitrogen inlet (208) and a second nitrogen outlet (209).

8. The pH adjusting device according to claim 6, wherein a second pressure gauge (210) is arranged on the second upper sealing head (203), and a second liquid level gauge (211) is arranged on the second tank body (202).

9. The pH adjusting device according to claim 6, wherein the salt forming kettle (3) comprises a third kettle body (302), a third upper end enclosure (303) arranged on the upper side of the third kettle body (302) and a third lower end enclosure (304) arranged on the lower side of the third kettle body (302), a third stirring device (305) is arranged in the third kettle body (302), a salt-forming kettle amine material inlet (306) and a salt-forming kettle acid material inlet (307) are arranged on the third upper sealing head (303), a salt forming kettle salt material outlet (308) is arranged on the third lower end socket (304), the pH meter (301) is arranged in the third kettle body (302), a first amine pipeline (5) is arranged between the amine material inlet (306) and the amine material outlet (108) of the salt-forming kettle and communicated with each other through the first amine pipeline (5), a second acid pipeline (6) is arranged between the acid material inlet (307) and the acid material outlet (207) of the salt forming kettle and communicated with each other through the second acid pipeline (6).

10. A pH adjusting device according to claim 9, wherein the first stirring device (105), the second stirring device (205) and the third stirring device (305) each comprise a stirring shaft and a stirring paddle connected with the stirring shaft.