阅读说明：本技术 从制糖离交脱色产生的纳滤浓缩液中提取天然色素的工艺 (Process for extracting natural pigment from nanofiltration concentrated solution generated by sugar production ion exchange decolorization ) 是由 蔡智全 杨德喜 于 2020-11-16 设计创作，主要内容包括：本发明提供一种从制糖离交脱色产生的纳滤浓缩液中提取天然色素的工艺,具体涉及色素提取工艺领域,具体步骤如下：S1、用50至70℃温水和离交废液混合进行纳滤透析,其中纳滤透析的截留分子量为30～240Da；压强为6～10MPa；pH值为3～7；温度为33～42℃；浓缩比为15至30倍；S2、经纳滤浓缩透析除盐后获得8至12％浓度的有机色素,然后经过蒸发设备浓缩获得固形物含量为60至74％的色素浓缩液；蒸发设备调整蒸汽量和真空度控制压力为80mmHg；S3、经杀菌的色素浓缩液再经纯水换热降温到33至37℃装桶入库。本发明可减少工厂污水COD排放量,降低污水氯根含量。(The invention provides a process for extracting natural pigment from nanofiltration concentrated solution generated by sugar-making ion exchange decolorization, and particularly relates to the field of pigment extraction processes, which comprises the following specific steps: s1, mixing warm water at 50-70 ℃ with the ion exchange waste liquid for nanofiltration dialysis, wherein the molecular weight cut-off of the nanofiltration dialysis is 30-240 Da; the pressure intensity is 6-10 MPa; the pH value is 3-7; the temperature is 33-42 ℃; concentration ratio is 15 to 30 times; s2, carrying out nanofiltration concentration, dialysis and desalination to obtain organic pigment with the concentration of 8-12%, and then concentrating by using evaporation equipment to obtain pigment concentrated solution with the solid content of 60-74%; the evaporation equipment adjusts the steam quantity and the vacuum degree and controls the pressure to be 80 mmHg; and S3, exchanging heat of the sterilized pigment concentrated solution by pure water, cooling to 33-37 ℃, barreling and warehousing. The invention can reduce the COD discharge of the factory sewage and reduce the chlorine content of the sewage.)

1. The process for extracting natural pigment from nanofiltration concentrated solution generated by sugar preparation ion exchange decolorization is characterized in that in the process of recovering salt by nanofiltration of sugar preparation ion exchange, after the nanofiltration production step is finished, the nanofiltration enters a dialysis step, and the process comprises the following steps: the method comprises the following specific steps: s1, mixing warm water at 50-70 ℃ with the ion exchange waste liquid for nanofiltration dialysis, wherein the molecular weight cut-off of the nanofiltration dialysis is 30-240 Da; the pressure intensity is 6-10 MPa; the pH value is 3-7; the temperature is 33-42 ℃; concentration ratio is 15 to 30 times; s2, carrying out nanofiltration concentration, dialysis and desalination to obtain organic pigment with the concentration of 8-12%, and then concentrating by using evaporation equipment to obtain pigment concentrated solution with the solid content of 60-74%; the evaporation equipment adjusts the steam quantity and the vacuum degree and controls the pressure to be 80 mmHg; and S3, exchanging heat of the sterilized pigment concentrated solution by pure water, cooling to 33-37 ℃, barreling and warehousing.

2. The process of claim 1, wherein the natural pigment is extracted from nanofiltration concentrate produced by sugar processing ion exchange decolorization: in the step S2, the concentration process of the evaporation equipment is specifically as follows: conveying the organic pigment solution to a primary evaporation separation device for separation, wherein one part of separation liquid is circulated back to the top of the falling film evaporation device through a pump, and the other part of separation liquid is conveyed into a secondary film evaporation device through a primary evaporation organic pigment conveying pump;

the organic pigment gas and the water vapor separated by the primary evaporation separation device are sucked into the primary evaporation condensation device through vacuum, the uncondensed gas is further sprayed and washed through the primary evaporation separation defoaming device, the condensed rare machine pigment solution firstly enters a primary evaporation rare machine pigment intermediate tank, then enters the primary evaporation separation defoaming device through a rare machine pigment circulating pump part, and the other part is conveyed to a rare machine pigment recovery device; the rare machine pigment solution which passes through the primary evaporation separation defoaming device enters a secondary evaporation rare machine pigment intermediate tank.

3. The process of claim 1, wherein the natural pigment is extracted from nanofiltration concentrate produced by sugar processing ion exchange decolorization: in the step S1, the mixture of 60 ℃ warm water and ion exchange waste liquid is used for nanofiltration dialysis, wherein the molecular weight cut-off of the nanofiltration dialysis is 80 Da; the pressure intensity is 7 MPa; the pH value is 6.5; the temperature is 35 ℃; the concentration ratio was 20 times.

4. The process of claim 1, wherein the natural pigment is extracted from nanofiltration concentrate produced by sugar processing ion exchange decolorization: in the step S2, organic pigment with the concentration of 10% is obtained after nanofiltration, concentration, dialysis and desalination, and then pigment concentrated solution with the solid content of 67% is obtained through concentration by evaporation equipment.

5. The process of claim 2 for extracting natural pigment from nanofiltration concentrate produced by sugar processing ion exchange decolorization, wherein: in the step S2, the temperature in the primary evaporation separation device is 50 ℃, and the pressure is 80 mmHg; the temperature in the first-stage evaporation and condensation device is 30 ℃.

6. The process of claim 5 for extracting natural pigment from nanofiltration concentrate produced by sugar processing ion exchange decolorization, wherein: in the step S2, the bottom of the falling film evaporation device, the primary evaporation separation device and the pipeline for conveying the organic pigment are heated by hot water with the temperature of 75 ℃, and the temperature of the organic pigment in the falling film evaporation device is kept at 65 ℃.

7. The process of claim 1, wherein the natural pigment is extracted from nanofiltration concentrate produced by sugar processing ion exchange decolorization: and in the step S3, the sterilized and heat-exchanged pigment concentrated solution is cooled to 35 ℃ through pure water heat exchange, barreled and stored.

8. The process of claim 7, wherein the natural pigment is extracted from nanofiltration concentrate produced by sugar processing ion exchange decolorization: in step S3, the sterilization process is as follows: the bottom of the sterilization equipment enters water in a water storage tank heated to 95 ℃ by steam and is discharged from the top, the discharged water enters the water storage tank again, the temperature is raised and then is recycled for cold discharge, and a PLC control system regulates the opening and closing of a steam valve and an air escape valve to control the pressure in the equipment to be within a set range; steam enters the sterilization equipment from the bottom, the temperature is collected by adopting a temperature sensor, the pressure is collected by adopting a pressure sensor, and the opening and closing of a steam valve and an exhaust valve are adjusted by a PLC control system so that the temperature and the pressure are kept at set values for sterilization; after the sterilization stage is finished, the PLC control system opens the air supply valve, compressed air is introduced, the pressure is adjusted within a set range, cold water at 35-40 ℃ is introduced for cooling, the PLC control system adjusts the opening and closing of the exhaust valve and the air supply valve to keep the pressure within the set range, when the temperature in the equipment reaches the requirement of the equipment, the air supply valve is closed, and the drain valve is opened to drain water by using the pressure in the equipment.

9. The process of claim 1, wherein the natural pigment is extracted from nanofiltration concentrate produced by sugar processing ion exchange decolorization: the sterilized high-temperature pigment concentrated solution is sent back to the evaporator and concentrated before heat exchange, so that the pigment concentrated solution before evaporation and concentration is preheated.

Technical Field

The invention belongs to the field of pigment extraction processes, and particularly relates to a process for extracting natural pigment from nanofiltration concentrated solution generated by sugar preparation ion exchange decolorization.

Background

And separating the pigment from the alkaline sodium chloride solution by using a nanofiltration membrane. Nanofiltration is a technical means to separate suspended and dissolved substances using differences in molecular weight and size. The nanofiltration membrane shows a screening effect by utilizing the power of pressure difference. Substances smaller than the pore size of the membrane will constitute a filtrate as the solvent permeates the membrane; and particles larger than the size of the membrane pores are trapped to form the nanofiltration concentrate. At present, concentrated solution produced by nanofiltration in sugar industry in China is discharged into a sewage treatment plant; with the national policy of energy conservation and emission reduction, enterprises need to improve the economic benefit and aim to reduce the emission of pollutants;

in view of the above, a new process technology for extracting natural pigments from nanofiltration concentrated solution generated by sugar production ion exchange decolorization is needed, and after nanofiltration production is finished, the nanofiltration concentrated solution is not discharged, and the natural pigments are extracted by using a nanofiltration system and an evaporation and sterilization cooling system.

Disclosure of Invention

The invention aims to provide a process for extracting natural pigment from nanofiltration concentrated solution generated by sugar preparation, ion exchange and decoloration, which can reduce the amount of nanofiltration concentrated solution entering a sewage treatment plant, reduce the COD discharge amount of factory sewage, reduce the chlorine content of the sewage and is beneficial to biochemical treatment in the sewage treatment process.

The invention provides the following technical scheme:

a process for extracting natural pigment from nanofiltration concentrated solution generated by sugar preparation ion exchange decolorization comprises the following steps:

s1, mixing warm water at 50-70 ℃ with the ion exchange waste liquid for nanofiltration dialysis, wherein the molecular weight cut-off of the nanofiltration dialysis is 30-240 Da; the pressure intensity is 6-10 MPa; the pH value is 3-7; the temperature is 33-42 ℃; increasing salt to penetrate a nanofiltration membrane to enter dialysate, reducing the salt content in the concentrated solution, recovering the salt, and simultaneously concentrating the concentrated solution, wherein the concentration ratio is 15-30 times;

s2, carrying out nanofiltration concentration, dialysis and desalination to obtain organic pigment with the concentration of 8-12%, and then concentrating by using evaporation equipment to obtain pigment concentrated solution with the solid content of 60-74%; the evaporation equipment adjusts the steam quantity and the vacuum degree and controls the pressure to be 80 mmHg;

the concentration process of the evaporation equipment comprises the following specific steps: conveying the organic pigment solution to a primary evaporation separation device for separation, wherein one part of separation liquid is circulated back to the top of the falling film evaporation device through a pump, and the other part of separation liquid is conveyed into a secondary film evaporation device through a primary evaporation organic pigment conveying pump; the organic pigment gas and the water vapor separated by the primary evaporation separation device are sucked into the primary evaporation condensation device through vacuum, the uncondensed gas is further sprayed and washed through the primary evaporation separation defoaming device, the condensed rare machine pigment solution firstly enters a primary evaporation rare machine pigment intermediate tank, then enters the primary evaporation separation defoaming device through a rare machine pigment circulating pump part, and the other part is conveyed to a rare machine pigment recovery device; the rare machine pigment solution passing through the primary evaporation separation defoaming device enters a secondary evaporation rare machine pigment intermediate tank;

and S3, exchanging heat of the sterilized pigment concentrated solution by pure water, cooling to 33-37 ℃, barreling and warehousing.

Preferably, the sterilization comprises the following specific steps: the bottom of the sterilization equipment enters water in a water storage tank heated to 95 ℃ by steam and is discharged from the top, the discharged water enters the water storage tank again, the temperature is raised and then is recycled for cold discharge, and a PLC control system regulates the opening and closing of a steam valve and an air escape valve to control the pressure in the equipment to be within a set range;

steam enters the sterilization equipment from the bottom, the temperature is collected by adopting a temperature sensor, the pressure is collected by adopting a pressure sensor, and the opening and closing of a steam valve and an exhaust valve are adjusted by a PLC control system so that the temperature and the pressure are kept at set values for sterilization;

after the sterilization stage is finished, the PLC control system opens the air supply valve, compressed air is introduced, the pressure is adjusted within a set range, cold water at 35-40 ℃ is introduced for cooling, the PLC control system adjusts the opening and closing of the exhaust valve and the air supply valve to keep the pressure within the set range, when the temperature in the equipment reaches the requirement of the equipment, the air supply valve is closed, and the drain valve is opened to drain water by using the pressure in the equipment.

Preferably, the sterilized high-temperature pigment concentrated solution is sent back to the evaporator and concentrated for heat exchange, so that the pigment concentrated solution before the evaporator and the concentration is preheated

Preferably, in the step S1, the nanofiltration dialysis is carried out by mixing warm water at 60 ℃ with the ion exchange waste liquid, wherein the molecular weight cut-off of the nanofiltration dialysis is 80 Da; the pressure intensity is 7 MPa; the pH value is 6.5; the temperature is 35 ℃; the concentration ratio was 20 times.

Preferably, in the step S2, the organic pigment with a concentration of 10% is obtained after nanofiltration, concentration, dialysis and desalination, and then the pigment concentrated solution with a solid content of 67% is obtained by concentration through an evaporation device.

Preferably, in the step S2, the temperature in the primary evaporation and separation device is 50 ℃, and the pressure is 80 mmHg; the temperature in the primary evaporation and condensation device is 30 ℃;

preferably, in the step S2, the bottom of the falling film evaporation device, the primary evaporation separation device and the pipeline for conveying the organic pigment are subjected to heat tracing by using hot water at 75 ℃, so that the temperature of the organic pigment in the falling film evaporation device is kept at 65 DEG C

Preferably, in the step S3, the sterilized heat-exchanged pigment concentrated solution is cooled to 35 ℃ by heat exchange with pure water, and then is barreled and stored.

The invention has the beneficial effects that:

on the basis of the existing process equipment, the invention adds equipment of an evaporation and sterilization cooling system, fully utilizes nanofiltration concentrated solution discharged into a sewage system, provides a brand-new process technology for producing natural pigment, fully utilizes heat generated by high-temperature sterilization of the pigment concentrated solution to preheat the pigment solution before evaporation and concentration, and reduces the use of related heat sources (steam); the water consumption for dialysis is increased in the nanofiltration process, the salt content of nanofiltration concentrated solution is reduced, a set of evaporation equipment is added after nanofiltration, and a sterilization and cooling process is added after evaporation, so that the sanitation index of the product is ensured, and the requirement of long-time storage is met. Reduce the nanofiltration concentrated solution entering a sewage treatment plant and reduce the COD discharge of the sewage of the plant. The chlorine content of the sewage is reduced, and the biochemical treatment in the sewage treatment process is facilitated;

drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

Example 1

A process for extracting natural pigment from nanofiltration concentrated solution generated by sugar preparation ion exchange and decolorization comprises the following steps of, in the process of recovering salt by nanofiltration of sugar preparation ion exchange, after the nanofiltration production step is completed, the nanofiltration enters a dialysis step:

s1, mixing warm water at 50-70 ℃ with the ion exchange waste liquid for nanofiltration dialysis, wherein the molecular weight cut-off of the nanofiltration dialysis is 30 Da; the pressure intensity is 6 MPa; the pH value is 3; the temperature is 33 ℃; increasing salt to penetrate a nanofiltration membrane to enter dialysate, reducing the salt content in the concentrated solution, recovering the salt, and simultaneously concentrating the concentrated solution, wherein the concentration ratio is 15 times;

s2, carrying out nanofiltration concentration, dialysis and desalination to obtain an organic pigment with the concentration of 8%, and then concentrating by an evaporation device to obtain a pigment concentrated solution with the solid content of 60%; the evaporation equipment adjusts the steam quantity and the vacuum degree and controls the pressure to be 80 mmHg;

the concentration process of the evaporation equipment comprises the following specific steps: conveying the organic pigment solution to a primary evaporation separation device for separation, wherein one part of separation liquid is circulated back to the top of the falling film evaporation device through a pump, and the other part of separation liquid is conveyed into a secondary film evaporation device through a primary evaporation organic pigment conveying pump; the organic pigment gas and the water vapor separated by the primary evaporation separation device are sucked into the primary evaporation condensation device through vacuum, the uncondensed gas is further sprayed and washed through the primary evaporation separation defoaming device, the condensed rare machine pigment solution firstly enters a primary evaporation rare machine pigment intermediate tank, then enters the primary evaporation separation defoaming device through a rare machine pigment circulating pump part, and the other part is conveyed to a rare machine pigment recovery device; the rare machine pigment solution passing through the primary evaporation separation defoaming device enters a secondary evaporation rare machine pigment intermediate tank;

the temperature in the first-stage evaporation separation device is 50 ℃, and the pressure is 80 mmHg; the temperature in the primary evaporation and condensation device is 30 ℃; the bottom of the falling film evaporation device, the primary evaporation separation device and the pipeline for conveying the organic pigment are heated by hot water of 75 ℃ to keep the temperature of the organic pigment in the falling film evaporation device at 65 DEG C

S3, sending the sterilized high-temperature pigment concentrated solution back to the evaporation and concentration device for heat exchange to preheat the pigment concentrated solution before evaporation and concentration, then sterilizing, feeding water heated to 95 ℃ by steam into the bottom of the sterilization device and discharging the water from the top, feeding the discharged water into the water storage tank again, heating and then recycling for cooling, and regulating the pressure in the opening and closing control device of a steam valve and an air escape valve to be within a set range by a PLC control system; steam enters the sterilization equipment from the bottom, the temperature is collected by adopting a temperature sensor, the pressure is collected by adopting a pressure sensor, and the opening and closing of a steam valve and an exhaust valve are adjusted by a PLC control system so that the temperature and the pressure are kept at set values for sterilization;

after the sterilization stage is finished, the PLC control system opens the air supply valve, compressed air is introduced, the pressure is adjusted within a set range, cold water at 35-40 ℃ is introduced for cooling, the PLC control system adjusts the opening and closing of the exhaust valve and the air supply valve to keep the pressure within the set range, when the temperature in the equipment reaches the requirement of the equipment, the air supply valve is closed, and the drain valve is opened to drain water by using the pressure in the equipment. The sterilized pigment concentrated solution is cooled to 33 ℃ through pure water heat exchange and then is barreled and put in storage;

example 2

A process for extracting natural pigment from nanofiltration concentrated solution generated by sugar preparation ion exchange and decolorization comprises the following steps of, in the process of recovering salt by nanofiltration of sugar preparation ion exchange, after the nanofiltration production step is completed, the nanofiltration enters a dialysis step:

s1, mixing warm water at 60 ℃ with the ion exchange waste liquid for nanofiltration dialysis, wherein the molecular weight cut-off of the nanofiltration dialysis is 80 Da; the pressure intensity is 7 MPa; the pH value is 6.5; the temperature is 35 ℃; salt is increased to permeate the nanofiltration membrane to enter the dialysate, the salt content in the concentrated solution is reduced, the salt is recovered, and meanwhile, the concentration ratio of the concentrated solution is 20 times;

s2, carrying out nanofiltration concentration, dialysis and desalination to obtain organic pigment with the concentration of 10%, and then concentrating by using evaporation equipment to obtain pigment concentrated solution with the solid content of 67%; the evaporation equipment adjusts the steam quantity and the vacuum degree and controls the pressure to be 80 mmHg;

the concentration process of the evaporation equipment comprises the following specific steps: conveying the organic pigment solution to a primary evaporation separation device for separation, wherein one part of separation liquid is circulated back to the top of the falling film evaporation device through a pump, and the other part of separation liquid is conveyed into a secondary film evaporation device through a primary evaporation organic pigment conveying pump; the organic pigment gas and the water vapor separated by the primary evaporation separation device are sucked into the primary evaporation condensation device through vacuum, the uncondensed gas is further sprayed and washed through the primary evaporation separation defoaming device, the condensed rare machine pigment solution firstly enters a primary evaporation rare machine pigment intermediate tank, then enters the primary evaporation separation defoaming device through a rare machine pigment circulating pump part, and the other part is conveyed to a rare machine pigment recovery device; the rare machine pigment solution passing through the primary evaporation separation defoaming device enters a secondary evaporation rare machine pigment intermediate tank;

the temperature in the first-stage evaporation separation device is 50 ℃, and the pressure is 80 mmHg; the temperature in the primary evaporation and condensation device is 30 ℃; the bottom of the falling film evaporation device, the primary evaporation separation device and the pipeline for conveying the organic pigment are heated by hot water of 75 ℃ to keep the temperature of the organic pigment in the falling film evaporation device at 65 DEG C

S3, sending the sterilized high-temperature pigment concentrated solution back to the evaporation and concentration device for heat exchange to preheat the pigment concentrated solution before evaporation and concentration, then sterilizing, feeding water heated to 95 ℃ by steam into the bottom of the sterilization device and discharging the water from the top, feeding the discharged water into the water storage tank again, heating and then recycling for cooling, and regulating the pressure in the opening and closing control device of a steam valve and an air escape valve to be within a set range by a PLC control system;

steam enters the sterilization equipment from the bottom, the temperature is collected by adopting a temperature sensor, the pressure is collected by adopting a pressure sensor, and the opening and closing of a steam valve and an exhaust valve are adjusted by a PLC control system so that the temperature and the pressure are kept at set values for sterilization;

after the sterilization stage is finished, the PLC control system opens the air supply valve, compressed air is introduced, the pressure is adjusted within a set range, cold water at 35-40 ℃ is introduced for cooling, the PLC control system adjusts the opening and closing of the exhaust valve and the air supply valve to keep the pressure within the set range, when the temperature in the equipment reaches the requirement of the equipment, the air supply valve is closed, and the drain valve is opened to drain water by using the pressure in the equipment. And (4) cooling the sterilized pigment concentrated solution to 35 ℃ through pure water heat exchange, barreling and warehousing.

Example 3

A process for extracting natural pigment from nanofiltration concentrated solution generated by sugar preparation ion exchange and decolorization comprises the following steps of, in the process of recovering salt by nanofiltration of sugar preparation ion exchange, after the nanofiltration production step is completed, the nanofiltration enters a dialysis step:

s1, mixing warm water at 50-70 ℃ with the ion exchange waste liquid for nanofiltration dialysis, wherein the molecular weight cut-off of the nanofiltration dialysis is 240 Da; the pressure intensity is 10 MPa; the pH value is 7; the temperature is 42 ℃; increasing salt to penetrate a nanofiltration membrane to enter dialysate, reducing the salt content in the concentrated solution, recovering the salt, and simultaneously concentrating the concentrated solution, wherein the concentration ratio is 30 times;

s2, carrying out nanofiltration concentration, dialysis and desalination to obtain an organic pigment with the concentration of 12%, and then concentrating by an evaporation device to obtain a pigment concentrated solution with the solid content of 74%; the evaporation equipment adjusts the steam quantity and the vacuum degree and controls the pressure to be 80 mmHg;

the concentration process of the evaporation equipment comprises the following specific steps: conveying the organic pigment solution to a primary evaporation separation device for separation, wherein one part of separation liquid is circulated back to the top of the falling film evaporation device through a pump, and the other part of separation liquid is conveyed into a secondary film evaporation device through a primary evaporation organic pigment conveying pump; the organic pigment gas and the water vapor separated by the primary evaporation separation device are sucked into the primary evaporation condensation device through vacuum, the uncondensed gas is further sprayed and washed through the primary evaporation separation defoaming device, the condensed rare machine pigment solution firstly enters a primary evaporation rare machine pigment intermediate tank, then enters the primary evaporation separation defoaming device through a rare machine pigment circulating pump part, and the other part is conveyed to a rare machine pigment recovery device; the rare machine pigment solution passing through the primary evaporation separation defoaming device enters a secondary evaporation rare machine pigment intermediate tank; the temperature in the first-stage evaporation separation device is 50 ℃, and the pressure is 80 mmHg; the temperature in the primary evaporation and condensation device is 30 ℃; the bottom of the falling film evaporation device, the primary evaporation separation device and the pipeline for conveying the organic pigment are heated by hot water of 75 ℃, and the temperature of the organic pigment in the falling film evaporation device is kept at 65 ℃.

S3, sending the sterilized high-temperature pigment concentrated solution back to the evaporation and concentration device for heat exchange to preheat the pigment concentrated solution before evaporation and concentration, then sterilizing, feeding water heated to 95 ℃ by steam into the bottom of the sterilization device and discharging the water from the top, feeding the discharged water into the water storage tank again, heating and then recycling for cooling, and regulating the pressure in the opening and closing control device of a steam valve and an air escape valve to be within a set range by a PLC control system;

steam enters the sterilization equipment from the bottom, the temperature is collected by adopting a temperature sensor, the pressure is collected by adopting a pressure sensor, and the opening and closing of a steam valve and an exhaust valve are adjusted by a PLC control system so that the temperature and the pressure are kept at set values for sterilization;

after the sterilization stage is finished, the PLC control system opens the air supply valve, compressed air is introduced, the pressure is adjusted within a set range, cold water at 35-40 ℃ is introduced for cooling, the PLC control system adjusts the opening and closing of the exhaust valve and the air supply valve to keep the pressure within the set range, when the temperature in the equipment reaches the requirement of the equipment, the air supply valve is closed, and the drain valve is opened to drain water by using the pressure in the equipment. And (4) cooling the sterilized pigment concentrated solution to 37 ℃ through pure water heat exchange, barreling and warehousing.

And (3) analyzing experimental data:

the samples of examples 1 to 3 were tested separately, and the results were evaluated as follows:

physical and chemical analysis

Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that various changes, modifications and substitutions can be made without departing from the spirit and scope of the invention as defined by the appended claims. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.