阅读说明：本技术 一种连续生产维生素d3微胶囊粉的闭路循环工艺 (Closed cycle process for continuously producing vitamin D3 microcapsule powder ) 是由 杨阿三 卢艳蓉 程榕 郑燕萍 李琰君 贾继宁 屠美玲 孙勤 于 2020-05-29 设计创作，主要内容包括：本发明公开了一种连续生产维生素D3微胶囊粉的闭路循环工艺,其中包括造粒区、流化干燥区、产品筛分区以及干燥载气和淀粉循环再利用过程,维生素D3乳液在造粒区内完成喷雾造粒,通过降低造粒进风温度大大提高了造粒过程的成粒性和产品活性,在上下两股冷风作用下强化了淀粉对乳液的包覆作用,在流化干燥区通过分级干燥可以降低干燥温度,在保证干燥质量的前提下节约部分能源,在一体化设备内将造粒和干燥分区不仅减少了传输过程中的产品损耗,又能得到颗粒较为均匀微胶囊产品,该工艺流程采用干燥载气进行闭路分段循环,干燥载气重复利用节约了能耗,淀粉的回收再利用提高了淀粉利用率,减少粉尘排放,提高了生产过程中的安全性。(The invention discloses a closed cycle process for continuously producing vitamin D3 microcapsule powder, which comprises a granulation area, a fluidized drying area, a product screening area and a drying carrier gas and starch recycling process, wherein the vitamin D3 emulsion completes spray granulation in the granulation area, the granulation property and the product activity in the granulation process are greatly improved by reducing the granulation air inlet temperature, the coating effect of starch on the emulsion is enhanced under the action of upper and lower cold air flows, the drying temperature can be reduced by graded drying in the fluidized drying area, partial energy is saved on the premise of ensuring the drying quality, the product loss in the transmission process is reduced by dividing the granulation and drying areas in integrated equipment, microcapsule products with more uniform particles can be obtained, the process flow adopts the drying carrier gas to carry out closed cycle by sections, the drying carrier gas is repeatedly utilized, the energy consumption is saved, the starch utilization rate is improved by recycling of the starch, reduces dust emission and improves the safety in the production process.)

1. A closed cycle process for continuously producing vitamin D3 microcapsule powder is characterized by comprising the following steps:

1) spray granulation process in the granulation zone: a first fan (C-101) introduces two strands of cold air into the spray granulation tower (1), one strand of cold air is introduced into the spray granulation tower from the bottom of the spray granulation tower (1), the other strand of cold air entrains starch discharged by the powder conveying device and is blown into the spray granulation tower from an upper inlet of the spray granulation tower (1), an upper and a lower strands of cold air are formed in the spray granulation tower (1), and the starch is blown to diffuse in the spray granulation tower; meanwhile, the emulsion containing vitamin D3 in the emulsifying and homogenizing tank (V-101) is pressurized by a liquid inlet pump (P-101), then is sprayed into the spraying and granulating tower (1) through a top nozzle of the spraying and granulating tower and is atomized into fog drops, the fog drops are coated by starch to form wet particles, and the wet particles are discharged from an outlet at the lower side part of the spraying and granulating tower (1) under the entrainment effect of the two cold air streams;

2) a classification drying process in the fluidized drying zone: wet particles carried by cold air enter a primary fluidized drying bed (2), are dispersed and preliminarily pre-dried by low-temperature hot air introduced from the bottom of the primary fluidized drying bed (2), are sent into a secondary fluidized drying bed (3) and are dispersed and further deeply dried by high-temperature hot air introduced from the bottom of the secondary fluidized drying bed (3), and a dried crude product of the vitamin D3 microcapsule powder is discharged from a side outlet of the secondary fluidized drying bed (3); tail gas which is discharged from the tops of the primary fluidized drying bed (2) and the secondary fluidized drying bed (3) and contains fine starch particles is respectively sent into a primary bag-type dust collector (V-104) and a secondary bag-type dust collector (V-105) to further remove the fine starch particles, and the removed fine starch particles can be recycled;

3) and (3) screening process in the product screening area: the dried vitamin D3 microcapsule powder crude product enters a vibrating screen (V-106) through a discharging device connected with an outlet at the side part of the secondary fluidized drying bed (3) to screen out starch fine particles and a small amount of large lumps to obtain a vitamin D3 microcapsule powder product with qualified particle size, and the vitamin D3 microcapsule powder product is cooled, packaged and weighed;

4) the drying carrier gas recycling process comprises the following steps: gas coming out of the top of the primary fluidized drying bed (2) is dedusted by a primary bag-type deduster (V-104), pressurized by a second fan (C-102) and then sent into a condenser (E-103) for condensation and dehumidification, the condenser (E-103) discharges two paths of cold air, one path of cold air is heated by a first heater (E-101) to form high-temperature hot air and then sent into a secondary fluidized drying bed (3), and the other path of cold air is pressurized by the first fan (C-101) and then divided into two paths of cold air to be continuously sent into a spray granulation tower (1); and after the gas from the top of the secondary fluidized drying bed (3) is dedusted by a secondary bag-type deduster (V-105) and pressurized by a third fan (C-103), the gas is heated by a second heater (E-102) to form low-temperature hot air and then is sent into the primary fluidized drying bed (2), so that a closed circulation process of drying carrier gas is formed.

2. A closed cycle process for continuously producing vitamin D3 microcapsule powder according to claim 1, wherein the powder delivery device comprises a fresh starch feeding bin (V-102), a starch feeder (M-102) and a screw feeder (M-103), the outlet of the fresh starch feeding bin (V-102) is connected to the inlet of the starch feeder (M-102) through a pipeline, the outlet of the starch feeder (M-102) is connected to the inlet of the screw feeder (M-103) through a discharge device, the outlet of the screw feeder (M-103) is connected to one inlet of a feeding tee, and the other two inlets of the feeding tee are connected to the upper inlet of the spray granulation tower (1) and the first fan (C-101) through pipelines, so that the starch discharged from the powder delivery device can be entrained by a cold wind discharged from the first fan (C-101) and introduced into the spray granulation tower (1) ) And (4) the following steps.

3. The closed cycle process for continuously producing vitamin D3 microcapsule powder according to claim 1, wherein in the step 4), the carrier gas is recycled in a segmented manner, the high-temperature hot air heated by the first heater (E-101) is divided into two streams to be discharged, one stream of the high-temperature hot air is introduced into the secondary fluidized drying bed (3) from the bottom of the secondary fluidized drying bed (3), and the other stream of the high-temperature hot air is pressurized by the fourth fan (C-104) and then carries the fine starch particles discharged from the bottoms of the primary bag-type dust collector (V-104) and the secondary bag-type dust collector (V-105) together with the fine starch particles to be dried and conveyed to the tertiary bag-type dust collector (V-103) for gas-solid separation; meanwhile, a third path of cold air is discharged from the condenser (E-103), fine starch particles screened by the vibration screening device (V-106) are entrained by the third path of cold air discharged from the condenser (E-103) and conveyed to enter a third-stage bag-type dust collector (V-103) for gas-solid separation, and the fine starch particles separated from the bottom of the third-stage bag-type dust collector (V-103) are conveyed by the powder conveying device and conveyed into the spray granulation tower (1) again, so that the cyclic recycling of starch is realized; and the dedusted gas coming out of the tops of the three-stage bag-type dust remover (V-103) and the two-stage bag-type dust remover (V-105) is pressurized by a third fan (C-103), heated by a second heater (E-102) to form low-temperature hot air, and then sent into the primary fluidized drying bed (2) to form a closed circulation process of drying carrier gas.

4. The closed cycle process for continuously producing vitamin D3 microcapsule powder according to claim 3, wherein outlets at the bottoms of the primary bag-type dust collector (V-104), the secondary bag-type dust collector (V-105) and the tertiary bag-type dust collector (V-103) are connected with a feeding tee through a discharging device, and fine starch particles entering the feeding tee can be entrained by the introduced gas and discharged.

5. The closed cycle process for continuously producing vitamin D3 microcapsule powder according to claim 1, wherein the viscosity of the vitamin D3-containing emulsion is controlled to 30-60cP and the temperature of the vitamin D3-containing emulsion is controlled to 70-80 ℃ during the spray granulation in step 1).

6. The closed cycle process for continuously producing vitamin D3 microcapsule powder according to claim 1, wherein the temperature of two cold air streams introduced into the spray granulation tower (1) during the spray granulation in step 1) is controlled to be 8-10 ℃.

7. The closed cycle process for continuously producing vitamin D3 microcapsule powder according to claim 1, wherein in the two-stage drying process of step 2), the temperature of the low-temperature hot air introduced from the bottom of the first fluidized drying bed (2) is 60 ℃ to 80 ℃, and the temperature of the tail gas from the top of the first fluidized drying bed (2) is 35 ℃ to 45 ℃; the moisture content of the wet granules discharged from the spray granulation tower (1) and entering the primary fluidized drying bed (2) is 20-30%, and the moisture content of the solid granules discharged from the primary fluidized drying bed (2) and entering the secondary fluidized drying bed (3) is 14-18%.

8. The closed cycle process for continuously producing vitamin D3 microcapsule powder according to claim 1, wherein in the two-stage drying process of step 2), the temperature of the high-temperature hot air introduced from the bottom of the secondary fluidized drying bed (3) is 70 ℃ to 90 ℃, and the temperature of the tail gas discharged from the top of the secondary fluidized drying bed (3) is 50 ℃ to 60 ℃; the humidity of the solid particles discharged from the primary fluidized drying bed (2) and fed into the secondary fluidized drying bed (3) is between 14% and 18%, and the humidity of the solid particles discharged from the secondary fluidized drying bed (3) and fed into the vibrating screen (V-106) is between 4% and 7%.

9. The closed cycle process for continuously producing vitamin D3 microcapsule powder as claimed in claim 1, wherein the drying carrier gas used in the whole closed cycle process is nitrogen.

Technical Field

The invention relates to a closed cycle process for continuously producing vitamin D3 microcapsule powder.

Background

Vitamin D3, also known as cholecalciferol, is the most commonly mentioned form of vitamin D, vitamin D3 is a fat soluble vitamin. It is also considered to be a hormone precursor acting on calcium and phosphorus metabolism. It is closely related to sunlight, also known as "sunlight vitamin". In recent years, a number of international studies on vitamin D have shown that: vitamin D is no longer considered a nutritional necessity only for the prevention of rickets in children. The health effects of vitamin D as a hormonal agent have been more widely recognized and documented in many clinical trials. As its food and pharmaceutical value is gradually recognized, the production of vitamin D also begins to be standardized and standardized.

Vitamin D3 products are classified into pharmaceutical, food and feed grades. Due to the development of animal husbandry and aquaculture, the vitamin D3 product is widely used for the production of feed additives. Among them, vitamin D3 microcapsule feed additive plays an important role in promoting the development of animal husbandry and aquaculture. Vitamin D3 produced in China is mainly a feed-grade product, but the defects of instability and difficult dispersion of particles exist at present, and the popularization of the vitamin D3 in livestock feed additives is influenced.

The microcapsule preparation method is generally divided into three types, namely a physical method, a physicochemical method, a chemical method and the like according to the properties, a capsule wall forming mechanism and a capsule forming condition, each type of method can be further divided into a plurality of preparation methods according to different operation processes, mainly comprising a spray drying method, a spray cooling method, an interfacial polymerization method and a complex coacervation method, the traditional method for industrially producing the vitamin microcapsule is the spray drying method, the spray drying process has high speed and high yield, but the rapid evaporation of a solvent influences the wall material coating effect, and a large amount of high-temperature hot air can inactivate core materials, the product quality is lower, the energy consumption is increased due to the use of a large amount of high-temperature carrier gas, and dust pollution and explosion threat exist.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention plans to adopt a microencapsulation technology to produce the feed grade vitamin D3 granules. Therefore, the process adopts integrated equipment to combine a spray granulation tower and a two-stage fluidized drying bed for use, so that the product loss in the transmission process is reduced, the air inlet temperature of granulation is reduced in the spray granulation process, the feed liquid is atomized and granulated at a lower temperature (in the spray granulation tower, fog drops are coated by starch to form wet particles, the wet particles are not easy to adhere together to form lumps at the lower air inlet temperature, so that the product activity is ensured), then the wet particles are preliminarily dried under low-temperature hot air to reduce the viscosity of the starch on the surfaces of the wet particles, and then the wet particles are further dried by using high-temperature hot air, so that the flow of carrier gas in the whole process forms a closed grading cycle, and the energy waste is reduced as much as possible. The closed cycle continuous production can ensure the production efficiency and obviously improve the granulation quality of the microcapsules, the drying quality is improved by controlling the air inlet drying temperature of the two-stage drying fluidized bed, the energy consumption is reduced in the production process, the starch is recycled, the dust pollution is reduced, and the continuous large-scale production is realized.

The closed cycle process for continuously producing the vitamin D3 microcapsule powder is characterized by comprising the following steps of:

1) spray granulation process in the granulation zone: a first fan introduces two strands of cold air into the spray granulation tower, one strand of cold air is introduced into the spray granulation tower from the bottom of the spray granulation tower, the other strand of cold air entrains starch discharged by the powder conveying device and is blown into the spray granulation tower from an upper inlet of the spray granulation tower, an upper strand of cold air and a lower strand of cold air are formed in the spray granulation tower, and the starch is blown to diffuse in the spray granulation tower; meanwhile, the emulsion containing vitamin D3 in the emulsification homogenizing tank is pressurized by a liquid inlet pump, then is sprayed into the spray granulation tower through a top nozzle of the spray granulation tower and is atomized into fog drops, the fog drops are coated by starch to form moisture-containing particles, and the moisture-containing particles are discharged from an outlet at the lower side part of the spray granulation tower under the entrainment effect of the two cold air streams;

2) a classification drying process in the fluidized drying zone: wet particles carried by cold air enter a primary fluidized drying bed, are dispersed and preliminarily pre-dried by low-temperature hot air introduced from the bottom of the primary fluidized drying bed, are sent into a secondary fluidized drying bed, are dispersed and further deeply dried by high-temperature hot air introduced from the bottom of the secondary fluidized drying bed, and a dried crude product of the vitamin D3 microcapsule powder is discharged through a side outlet of the secondary fluidized drying bed; tail gas which is discharged from the tops of the primary fluidized drying bed and the secondary fluidized drying bed and contains the starch fine particles is respectively sent into a primary bag-type dust remover and a secondary bag-type dust remover to further remove the starch fine particles, and the removed starch fine particles can be recycled;

3) and (3) screening process in the product screening area: feeding the dried vitamin D3 microcapsule powder crude product into a vibrating screen separator through a discharging device connected with an outlet at the side part of the secondary fluidized drying bed to screen out fine starch particles and a small amount of large lumps to obtain a vitamin D3 microcapsule powder product with qualified particle size, cooling, packaging and weighing;

4) the drying carrier gas recycling process comprises the following steps: the gas coming out of the top of the primary fluidized drying bed is dedusted by a primary bag-type dust remover, is pressurized by a second fan and then is sent into a condenser for condensation and dehumidification, the condenser discharges two paths of cold air, one path of cold air is heated by a first heater to form high-temperature hot air and then is sent into a secondary fluidized drying bed, and the other path of cold air is pressurized by the first fan and then is divided into two paths of cold air to be continuously sent into a spray granulation tower; and after the gas from the top of the secondary fluidized drying bed is dedusted by a secondary bag-type dust remover and pressurized by a third fan in sequence, the gas is heated by a second heater to form low-temperature hot air and then is sent into the primary fluidized drying bed, so that a closed cycle process of drying carrier gas is formed.

The closed cycle process for continuously producing the vitamin D3 microcapsule powder is characterized in that the powder conveying device comprises a fresh starch feeding bin, a starch feeder and a spiral feeder, an outlet at the bottom of the fresh starch feeding bin is connected with an inlet at the top of the starch feeder through a pipeline, an outlet at the bottom of the starch feeder is connected with an inlet of the spiral feeder through a discharger, an outlet of the spiral feeder is connected with an inlet of a feeding tee joint, and the other two inlets of the feeding tee joint are respectively connected with an inlet at the upper part of a spray granulation tower and a first fan through pipelines, so that starch discharged by the powder conveying device can be entrained by a cold blast discharged by the first fan and introduced into the spray granulation tower.

The closed cycle process for continuously producing the vitamin D3 microcapsule powder is characterized in that in the step 4), the carrier gas is recycled in a segmented mode in the process of drying the carrier gas, high-temperature hot air formed by heating through a first heater is divided into two parts to be discharged, one part of the high-temperature hot air is introduced into a second-stage fluidized drying bed from the bottom of the second-stage fluidized drying bed, the other part of the high-temperature hot air is pressurized through a fourth fan, and then fine starch particles discharged from the bottoms of a first-stage bag-type dust collector and a second-stage bag-type dust collector are entrained together, dried and conveyed into a third-stage bag-type dust; meanwhile, a third path of cold air is discharged from the condenser, the fine starch particles screened by the vibration screening device are entrained by the third path of cold air discharged from the condenser and conveyed to enter a third-stage bag-type dust collector for gas-solid separation, the fine starch particles separated from the bottom of the third-stage bag-type dust collector are conveyed by the powder conveying device and are conveyed into the spray granulation tower again, and the cyclic recycling of starch is realized; and the dedusted gas from the tops of the three-stage bag-type dust remover and the two-stage bag-type dust remover is pressurized by a third fan, heated by a second heater to form low-temperature hot air, and then sent into a primary fluidized drying bed to form a closed cycle process of drying carrier gas.

The closed cycle process for continuously producing the vitamin D3 microcapsule powder is characterized in that outlets at the bottoms of the primary bag-type dust collector, the secondary bag-type dust collector and the tertiary bag-type dust collector are connected with a feeding tee joint through a discharging device, and fine starch particles entering the feeding tee joint can be discharged by gas entrainment introduced into the feeding tee joint.

The closed cycle process for continuously producing the vitamin D3 microcapsule powder is characterized in that in the spray granulation process in the step 1), the viscosity of the vitamin D3 emulsion is controlled to be 30-60cP, and the temperature of the vitamin D3 emulsion is controlled to be 70-80 ℃.

The closed cycle process for continuously producing the vitamin D3 microcapsule powder is characterized in that in the spray granulation process in the step 1), the temperature of two cold air streams introduced into a spray granulation tower is controlled to be 8-10 ℃.

The closed cycle process for continuously producing the vitamin D3 microcapsule powder is characterized in that in the two-stage drying process in the step 2), the temperature of low-temperature hot air introduced from the bottom of a first-stage fluidized drying bed is 60-80 ℃, and the temperature of tail gas discharged from the top of the first-stage fluidized drying bed is 35-45 ℃; the moisture content of the wet granules exiting the spray granulation tower and entering the primary fluidized drying bed is between 20% and 30%, and the moisture content of the solid granules exiting the primary fluidized drying bed and entering the secondary fluidized drying bed is between 14% and 18%.

The closed cycle process for continuously producing the vitamin D3 microcapsule powder is characterized in that in the two-stage drying process in the step 2), the temperature of high-temperature hot air introduced from the bottom of the second-stage fluidized drying bed is 70-90 ℃, and the temperature of tail gas discharged from the top of the second-stage fluidized drying bed is 50-60 ℃; the humidity of the solid particles discharged from the primary fluidized drying bed and entering the secondary fluidized drying bed is between 14% and 18%, and the humidity of the solid particles discharged from the secondary fluidized drying bed and fed into the vibratory screen is between 4% and 7%.

The closed cycle process for continuously producing the vitamin D3 microcapsule powder is characterized in that the drying carrier gas adopted in the whole closed cycle process is nitrogen.

Compared with the prior art, the invention has the following beneficial effects:

(1) according to the technical scheme, a novel closed cycle process flow scheme is adopted to produce the vitamin D3 microcapsule, and the granulation integrity and the coating property of the vitamin D3 microcapsule are improved on the premise of ensuring the production efficiency. In the whole process of continuously producing the vitamin D3 microcapsule powder, the drying carrier gas forms closed cycle, and segmented cycle is adopted, so that the drying carrier gas is repeatedly utilized to dry and recycle the starch, the energy consumption is greatly saved, the starch is recycled, the utilization rate of the starch is improved, the dust emission is reduced, and the safety in the production process is improved.

(2) In the granulation area, the upper part and the bottom of a spray granulation tower are respectively provided with a granulation air inlet, one strand of cold air is introduced into the spray granulation tower from the bottom of the spray granulation tower, the other strand of cold air is blown into the spray granulation tower from an upper inlet of the spray granulation tower together with starch discharged by a powder conveying device, and an upper strand and a lower strand of cold air are formed in the spray granulation tower. The fog drops sprayed into the spray granulation tower from a nozzle at the top of the spray granulation tower violently turn over and slowly fall under the blowing of the upper and lower cold air flows, and are gradually cooled and formed in the process. The upper and lower cold air flows in reverse direction, so that the sedimentation of the fog drops can be effectively slowed down, and the process of coating and granulating the fog drops by starch is enhanced, thereby improving the integrity and coating property of the granulating.

(3) The invention adopts a two-stage bedroom fluidized drying bed for drying so as to obtain better dry microcapsule products, and tail gas discharged by a second-stage fluidized drying bed is dedusted, heated and then introduced into a first-stage fluidized drying bed for recycling. After dust removal, condensation and dehumidification of tail gas discharged by the primary fluidized drying bed, part of tail gas is heated and introduced into the secondary fluidized drying bed for recycling, and the other part of tail gas is introduced into a spray granulation tower as cold air for granulation to form a closed cycle drying process of gas, so that waste gas is treated and recycled for many times, energy consumption is saved, and compared with the traditional process for continuously producing vitamin D3 microcapsule powder in the prior art, the heating temperature of the dry gas in the whole process is lower, the inactivation loss of core materials of the vitamin D3 microcapsule powder is reduced, and the product quality is improved.

(4) In the whole granulation and drying process, the inert gas nitrogen used for the carrier gas not only reduces the oxidation loss in the microcapsule production process, but also ensures the safety of high-temperature mixing of the carrier gas and the starch.

(5) In the process of starch collection and treatment, the starch generated in the whole process is collected, recycled and reused, so that the utilization rate of the starch is greatly improved, and the dust pollution is reduced to a great extent.

Drawings

FIG. 1 is a schematic structural diagram of production equipment adopted in a closed cycle process for producing vitamin D3 microcapsule powder;

FIG. 2 is a schematic view showing the structure of the production equipment used in the open-circuit process for producing vitamin D3 microcapsule powder of example 4;

in the figure: 1-spray granulation tower, 2-first-stage fluidized drying bed, 3-second-stage fluidized drying bed, P-101 as a liquid inlet pump, C-101 as a first fan, C-102 as a second fan, C-103 as a third fan, C-104 as a fourth fan, C-105 as a fifth fan, V-101 as an emulsification homogenizing tank, V-103 as a third-stage bag-type dust remover, V-104 as a first-stage bag-type dust remover, V-105 as a second-stage bag-type dust remover, V-102 as a fresh starch feeding bin, V-106 as a vibration screening device, E-101 as a first heater, E-102 as a second heater, E-103 as a condenser, M-102 starch feeder, and M-103 screw feeder.

Detailed Description

The present invention is further illustrated by the following examples, which should not be construed as limiting the scope of the invention.