CN114870418A

CN114870418A - Jet flash dryer and solvent removal system of surfactant

Info

Publication number: CN114870418A
Application number: CN202210509040.3A
Authority: CN
Inventors: 祝红元; 张欣; 刘海华
Original assignee: Jiangsu Youyang Pharmaceutical Co ltd
Current assignee: Jiangsu Youyang Pharmaceutical Co ltd
Priority date: 2022-05-11
Filing date: 2022-05-11
Publication date: 2022-08-09

Abstract

The invention discloses a jet flash dryer and a solvent removal system of a surfactant; the jet flash dryer comprises a jet cylinder, an upper end enclosure is fixed at the upper end of the jet cylinder, and a first distribution plate, a first ejector, a second distribution plate and a second ejector are arranged in the jet cylinder; the upper end enclosure is connected with the first ejector through a flange, and the first distribution plate is clamped between the upper end enclosure and the first ejector; the first ejector and the second ejector are connected by using a flange, and a second distribution plate is clamped between the first ejector and the second ejector; the first distribution plate and the second distribution plate are respectively provided with small holes; the first ejector and the second ejector are respectively internally provided with an ejector pipe, and the ejector pipe is provided with an air inlet; the lower end of the injection cylinder body is connected with a gas-solid separation tank through a flange. The solvent removal system of the surfactant prevents the pipeline from being blocked due to too low temperature caused by vaporization heat absorption by utilizing the relationship between the boiling point of the volatile solvent and the evaporation pressure.

Description

Jet flash dryer and solvent removal system of surfactant

Technical Field

The invention relates to a jet flash dryer, in particular to a process for removing a surfactant which contains a low-boiling-point volatile solvent and is dried to be in a solid state.

Background

The production of pharmaceutical excipients often requires the use of solvents which are more hazardous and must be removed in the final preparation of the finished product. At present, the removal method which is used more is to heat and flash through a heating tower kettle or a circulating heat exchanger, the efficiency is lower, the required time is longer, and the finished product is easy to deteriorate. The change of the material state in the removal process causes that the process can not be carried out or the removal is not thorough. Some of the material that had been removed was not used as it became solid.

The production of the solid cetostearyl sulfate is carried out by producing 20-30% of monomer and then carrying out hot air spray drying. The industrial production process has large energy consumption, small yield and unstable quality. If the 70% monomer with a lower water content is prepared and then dried, it cannot be transported because the material is too fluid. If part of the volatile solvent is added at the time of 70% monomer neutralization, the fluidity improves.

In the industrial production process of MES, 20-40% of methanol is required to be added for preventing the generation of disodium salt; in addition, the addition of methanol maintained good flow of MES monomer. Finally, the drying process must remove the solvents such as ethanol and methanol.

The drying of the above materials generally uses hot air as a heat source, the relative humidity of the air at high temperature is very low, and the drying purpose is achieved by transferring the volatile matters in the wet materials into the air. However, air and organic solvents tend to form explosive mixtures and are highly dangerous.

Disclosure of Invention

The invention aims to provide a jet flash dryer and a solvent removal system containing a surfactant of the jet flash dryer aiming at the defects of the current manufacturing process and manufacturing equipment. In addition, the high-pressure steam can also be used as a power source to ensure that the mixture of volatile matters and volatile gases is in a vulcanization state, thereby achieving the purpose of flash evaporation with high speed and high efficiency.

The technical scheme adopted by the invention is as follows:

a spray flash dryer comprises a spray cylinder, wherein an upper end enclosure is fixed at the upper end of the spray cylinder, and a feed inlet is formed in the upper end enclosure; a first distribution plate, a first ejector, a second distribution plate and a second ejector are arranged in the ejection cylinder; the upper end enclosure is connected with the first ejector through a flange, and the first distribution plate is clamped between the upper end enclosure and the first ejector; the first ejector and the second ejector are connected by using a flange, and a second distribution plate is clamped between the first ejector and the second ejector; the first distribution plate and the second distribution plate are respectively provided with small holes; the first ejector and the second ejector are respectively internally provided with an ejector pipe, and the ejector pipe is provided with an air inlet; the lower end of the injection cylinder body is connected with a gas-solid separation tank through a flange; and a first air inlet and a second air inlet are formed in the side surface of the upper end of the injection cylinder.

The invention also discloses a solvent removal system of the surfactant, which comprises the jet flash dryer, a neutralization system, a feeding pump, a preheater, a heat circulating pump and a discharging extruder; the discharge hole of the neutralization system is connected with the lower feed inlet of the preheater through a feed pump; the upper discharge port of the preheater is divided into two paths, one path is connected with the lower feed port of the preheater through a heat circulating pump, and a check valve is arranged on the pipeline; the other path is connected with a feed inlet of the jet flash dryer, and a pipeline is provided with a back pressure valve; the lower end of the jet flash dryer is connected with a discharging extruder.

The sparging gas used can be steam, hot compressed air or nitrogen. And is changed according to the risk of the volatile solvent.

Furthermore, an outlet at the upper part of the gas-solid separation tank is connected with an air extraction system, and the air extraction system is changed according to different injected gases. The steam can use a vacuum pump, and the non-condensable gas can use a centrifugal fan to keep the negative pressure state of the gas-solid separator.

After the technical scheme is adopted, the invention has the beneficial effects that:

1. is suitable for flash evaporation drying of volatile solvent, especially for materials with high freezing point, such as cetostearyl alcohol sulfate, cetostearyl fatty acid methyl ester sulfonate, cetostearyl olefin sulfonate, and cetostearyl benzene sulfonate.

2. The drying device is suitable for drying high-concentration materials, and is energy-saving and environment-friendly.

3. The manufacturing process is high in safety.

Drawings

FIG. 1 is a schematic diagram of the connection of the solvent removal system of the present invention.

In the figure: 1-neutralization system, 2-feeding pump, 3-preheater, 4-heat circulating pump, 5-check valve, 6-back pressure valve, 7-jet flash dryer, 8-discharging extruder and 9-air extraction system.

FIG. 2 is a schematic diagram of the construction of a jet flash dryer of the present invention;

the jet flash dryer comprises: 70-feeding port, 71-upper end enclosure, 72-first distribution plate, 73-first injector, 731-injection pipe, 732-air inlet, 74-second distribution plate, 75-second injector, 76-air inlet I, 77-air inlet II, 78-discharging port and 79-gas-solid separation tank.

Detailed Description

The invention will be further described with reference to the accompanying drawings.

Example 1

As shown in fig. 2: a jet flash dryer comprises a jet cylinder, wherein an upper end enclosure 71 is fixed at the upper end of the jet cylinder, and a feed inlet 70 is formed in the upper end enclosure 71; a first distribution plate 72, a first injector 73, a second distribution plate 74 and a second injector 75 are arranged in the injection cylinder; the upper head 71 and the first ejector 73 are connected using a flange, and the first distribution plate 72 is sandwiched therebetween. The first and

second injectors

73 and 75 are connected using flanges with the second distribution plate 74 sandwiched therebetween. The first distribution plate and the second distribution plate are respectively provided with small holes; an injection pipe 731 is respectively arranged in the first injector and the second injector, and an air inlet 732 is arranged on the injection pipe; the lower end of the injection cylinder body is connected with a gas-solid separation tank 79 through a flange.

In the injection flash dryer 7, 70% of slurry material flows into the upper seal head 71 from the upper feed inlet 70, and due to the flow limiting effect of the small holes in the first distribution plate 72, fluid is uniformly distributed through the small holes in the first distribution plate 72 and is injected into the first injector 73, and each small hole is connected with an injection pipe. The sectional area of the small hole is small, the flow speed is high, the flow speed is reduced rapidly after the material is sprayed into the spraying pipe, the volatile solvent is evaporated, and heat is absorbed, so that the temperature of the material in the spraying pipe is reduced rapidly. The side surface of the upper end of the injection cylinder body is provided with a first air inlet 76 and a second air inlet 77, a plurality of vertically arranged injection pipes are arranged in the first injector 73, an air inlet is arranged at the upper part of each injection pipe, steam enters the air inlet of the injection pipe from the first air inlet 76 and is mixed and heated with the monomer injected from the small holes on the first distribution plate, and the injection pipe is prevented from being blocked due to sudden reduction of the temperature of the material. The mixed heated monomer feed travels downward through the orifices in the second distributor plate 74 and is injected into the second injector 75.

The internal structure of the second ejector 75 is the same as that of the first ejector 73, except that the diameter of the injection pipe and the diameter of the air inlet hole of the injection pipe inside the second ejector 75 are larger than those of the injection pipe inside the first ejector 73. The monomer and the steam are mixed and heated for the second time and then flow out to the gas-solid separation tank 79 through the discharge port 78, and the volatile gas and the high-temperature molten material are separated. The second ejector 75 and the gas-solid separation tank 79 are connected by flange pressing. The volatile gas is sucked away by the gas-bleed system 9 through an outlet at the upper part of the gas-solid separation tank 79. The high-temperature molten material falls to the bottom of the gas-solid separation tank 79 and is output and reprocessed through the discharging extruder 8.

Example 2

As shown in fig. 1, a solvent removal system for a surfactant comprises the aforementioned jet flash dryer 7, and further comprises a neutralization system 1, a feed pump 2, a preheater 3, a heat circulation pump 4 and a discharge extruder 8; a discharge hole of the neutralization system 1 is connected with a feed inlet at the lower part of the preheater 3 through a feed pump 2; the discharge port at the upper part of the preheater is divided into two paths, one path is connected with the feed port at the lower part of the preheater 3 through a heat circulating pump 4, and a check valve 5 is arranged on the pipeline; the other path is connected with a feed inlet 70 of the jet flash dryer 7, and a pipeline is provided with a back pressure valve 6; the lower end of the jet flash dryer 7 is connected with a discharge extruder 8.

The sulfonated acid ester, liquid alkali and solvent react in a neutralization system 1 to obtain high-concentration monomers, materials in the neutralization system are conveyed by a feed pump 2 and mixed with hot materials conveyed by a circulating pump 4, the materials are conveyed to a lower feed inlet of a preheater 3 to be heated, and the materials flow out from an upper discharge outlet of the preheater and are divided into two paths. One path of the waste water is circulated by a heat circulating pump 4 and returns to a feed inlet of the preheater through a check valve 5; the other path is controlled by a backpressure valve 6 and then is conveyed to a feed port 70 of the jet flash dryer 7.

The material preheating system, the material carries out circulation heating through hot circulating pump 4 and pre-heater 3, mainly prevents that the material velocity of flow distributes unevenly, and the velocity of flow is slow, and long waiting time waits that the factor arouses the material rotten, block up in the unable high-efficient monomer material of transferring of pipeline heat. Thermal cycle material flow: feed pump transport material = (5-10): 1. the back pressure, which differs according to the boiling point of the solvent, is in principle higher than the saturated vapor pressure of the heated material. The steam pressure is generally not more than 1.0 MPa. Under the condition of guaranteeing the material quality, the temperature drop that the improvement heating temperature can effectively prevent to spray the flash distillation and arouse blocks up the injection pipe.

The monomer material is subjected to two-stage jet flash drying. Can prevent to arouse because of preheater heating energy is not enough that a flash distillation is incomplete, arouse that the monomer temperature is too low to cause the pipe blockage, can prevent excessive flash distillation through the diameter control flash distillation pressure of control injection pipe again to increase steam and monomer material hybrid heating effect. The secondary flash evaporation is to continuously supplement energy on the basis of the primary flash evaporation, so that the volatile solvent in the monomer material is fully volatilized, and the aim of drying is fulfilled.

The working principle is as follows:

step one, circularly heating back pressure;

the acid ester, the liquid alkali and the solvent react in the neutralization system 1 to generate slurry monomer containing the volatile solvent, and the slurry monomer is metered by a feed pump 2 and then is mixed with the circulating hot material to be conveyed to a preheater 3 for heating. The main purpose of the heat material circulation heating is to keep the material reaching a certain flow rate and prevent the material from deteriorating due to low flow rate in the preheater. The temperature of the material in the preheating process rises, so that the volatile solvent cannot be vaporized, and the pressure must be kept above the vapor pressure of the preheated solvent.

Secondly, secondary injection flash evaporation drying;

the preheated monomer is conveyed to an injection flash dryer 7 through a backpressure valve 6, is firstly injected into an injection pipe in a first injector 73 through a small hole of a first distribution plate 72, the flow rate and the pressure are rapidly reduced, the volatile solvent is partially evaporated, the heat is absorbed, and the temperature of the material is reduced. The jet steam enters the jet pipe through the air inlet hole to be mixed with the material and provides heat for the material. The diameter of the injection pipe in the first injector must not be too large, on the one hand, the first flash is not controlled fast and the heat supply is not satisfactory. In addition, the pipe diameter is too large, and the mixed heating effect of the materials and the steam is poor.

The material after the first flash evaporation is partially vaporized, and the complete flash evaporation also needs to be continuously supplemented with energy. Therefore, after the first flash evaporation, the material is sprayed into the spraying pipe in the second sprayer 75 through the small holes on the second distribution plate 74, the pressure in the spraying pipe is continuously reduced to a negative pressure state, the volatile solvent is continuously evaporated, the temperature is further reduced, the high-pressure steam enters the spraying pipe to be further mixed and heated with the material, and the material subjected to gas-solid separation is timely conveyed into the gas-solid separation tank 79 for separation. If the material is not heated by the injected steam, the problems of too low temperature, poor fluidity and the like of the material are easily caused, and meanwhile, the separated material cannot be removed in time because the gas and the solid cannot form a good vulcanization state, so that the pipeline is easily blocked.

Example 3

A solvent removal system as described in example 2 was employed.

The MESA acid ester, the liquid alkali and the methanol generate 65% of hexadecadecyl fatty acid methyl ester sulfonate in the neutralization system 1, the temperature is about 50 ℃, the materials which are conveyed by the feed pump 2 and circulated at 130 ℃ are mixed and then enter the preheater 3 for heating, the temperature after heating is 130 ℃, and the backpressure pressure is 0.9 MPa. The circulation ratio is 5: 1, i.e. the flow rate in the preheater, increased by a factor of 5.

The preheated monomer feed is fed to a jet flash dryer 7 where the pressure is reduced to 0.4 MPa. Then enters the injection pipe in the first injector 73 through the small holes on the upper end enclosure and the first distribution plate 72, the temperature is reduced, the temperature is kept above 110 ℃ by supplementing steam in the injection pipe, and the pressure is kept at 0.2 MPa. Then the mixture is conveyed into the injection pipe in the second injector 75 through the small holes on the second distribution plate 74, the outlet temperature is kept above 105 ℃, and the pressure is kept at-0.085 MPa. The gas-solid phases leave the injection pipe and are separated in a gas-solid separation tank 79. The 105 ℃ gas is condensed and removed by a vacuum pump, and the MES in a molten state is conveyed to the next process by a discharge extruder 8. The degree of drying is controlled by the flow of the hexadecanoic acid methyl ester sulfonate.

Claims

1. A jet flash dryer characterized by: the device comprises a spraying cylinder body, wherein an upper end enclosure (71) is fixed at the upper end of the spraying cylinder body, and a feeding hole (70) is formed in the upper end enclosure (71); a first distribution plate (72), a first ejector (73), a second distribution plate (74) and a second ejector (75) are arranged in the ejection cylinder; the upper end socket (71) is connected with the first ejector (73) by using a flange, and a first distribution plate (72) is clamped between the upper end socket and the first ejector; the first injector (73) and the second injector (75) are connected by a flange, and a second distribution plate (74) is clamped between the first injector and the second injector; the first distribution plate and the second distribution plate are respectively provided with small holes; the first ejector and the second ejector are respectively internally provided with an ejector pipe, and the ejector pipes are provided with air inlet holes; the lower end of the injection cylinder body is connected with a gas-solid separation tank (79) through a flange; and a first air inlet (76) and a second air inlet (77) are formed in the side surface of the upper end of the injection cylinder.

2. A jet flash dryer according to claim 1, wherein: the pipe diameter of the injection pipe in the second injector (75) and the caliber of the air inlet hole of the injection pipe are respectively larger than the pipe diameter of the injection pipe in the first injector (73) and the caliber of the air inlet hole of the injection pipe.

3. A jet flash dryer according to claim 1, wherein: and an outlet at the upper part of the gas-solid separation tank (79) is connected with an air extraction system (9).

4. A solvent removal system comprising the surfactant of the jet flash dryer of any of claims 1-3, wherein: the device also comprises a neutralization system (1), a feeding pump (2), a preheater (3), a heat circulating pump (4) and a discharging extruder (8); a discharge hole of the neutralization system (1) is connected with a feed inlet at the lower part of the preheater (3) through a feed pump (2); the discharge port at the upper part of the preheater is divided into two paths, one path is connected with the feed port at the lower part of the preheater (3) through a heat circulating pump (4), and a check valve (5) is arranged on the pipeline; the other path is connected with a feed inlet (70) of the jet flash dryer (7), and a pipeline is provided with a back pressure valve (6); the lower end of the jet flash dryer (7) is connected with a discharging extruder (8).