JP5362124B2 - Freeze vacuum dryer - Google Patents

Description

  The present invention relates to a freeze vacuum drying apparatus.

  Conventionally, the freeze-drying method is often used in the field of pharmaceuticals and foods as a method of drying and taking out solid components such as solutes dissolved in raw material liquids and dispersed dispersions as fine powders. Yes.

FIG. 3 is an internal configuration diagram of a conventional freeze-drying apparatus.
The conventional freeze-drying apparatus 100 includes a vacuum chamber 111, a vacuum exhaust unit 112 that evacuates the vacuum chamber 111, an injector 114 that injects a raw material liquid into the vacuum chamber 111, and a lower portion of the injector 114. The heating / cooling shelf 116 and the tilting device 118 that rotates the heating / cooling shelf 116 around the one rotation axis 117 by a predetermined angle are provided.

When the raw material liquid is injected from the injector 114 into the vacuum evacuated vacuum chamber 111, the liquid component is evaporated from the injected raw material liquid and cooled, and frozen particles at least partially self-frozen are generated.
A cold trap 119 is disposed in the vacuum chamber 111, and the evaporated liquid component adheres to the cold trap 119 and is collected.

  When the posture of the heating / cooling shelf 116 is a horizontal posture where the surface is horizontal, the generated frozen particles fall and accumulate on the surface of the heating / cooling shelf 116. When the surface of the heating / cooling shelf 116 is cooled, if the frozen particles accumulated include an unfrozen portion, the unfrozen portion is also frozen.

After freezing the frozen particles, the surface of the heating / cooling shelf 116 is heated to supply latent heat of evaporation to the frozen particles, thereby accelerating sublimation of the liquid component. Dry particles are produced when the frozen particles are dried.
After the frozen particles are dried, the heating / cooling shelf 116 is brought into an inclined posture in which the dry particles deposited on the surface fall by the inclination device 118 in a state where the valve body 135 is separated from the valve seat 134. The dried particles dropped from the heating / cooling shelf 116 pass through the inside of the connection pipe 131 and move into the recovery tank 132 evacuated by the sub-vacuum exhaust unit 138.

  In the conventional freeze-drying apparatus 100, some of the generated frozen particles fall outside the heating / cooling shelf 116 through the gap between the heating / cooling shelf 116 and the inner periphery of the vacuum chamber 111, There was a problem that the recovery rate of frozen particles was lowered. In the present invention, the ratio of the dry particles recovered in the recovery tank 132 among the dry particles is referred to as “recovery rate”.

  In Patent Document 1, in order to guide the frozen particles descending near the inner wall of the vacuum chamber to a collection plate corresponding to a heating / cooling shelf, a ring-shaped guide portion is provided along the inner periphery of the vacuum chamber at a position above the collection plate. Although the guide unit is arranged at a position away from the collection plate so that it does not come into contact when the collection plate is in an inclined posture, the frozen particles pass through the gap between the guide unit and the collection plate. It was difficult to prevent falling outside the collecting plate.

Japanese Patent Laid-Open No. 2004-232883

  The present invention was created to solve the above-described disadvantages of the prior art, and an object thereof is to provide a technique for improving the recovery rate of frozen particles in a freeze vacuum drying apparatus.

In order to solve the above-described problems, the present invention provides a vacuum chamber, a vacuum exhaust section that evacuates the vacuum chamber, and an injection that generates frozen particles by injecting a raw material liquid into the vacuum chamber that has been evacuated. And a heating / cooling shelf arranged below the injector, and the heating / cooling shelf is rotated by a predetermined angle around one rotation axis, and the surface of the heating / cooling shelf is horizontal and generated. The horizontal posture in which the frozen particles accumulate on the surface, and one end of the heating / cooling shelf is located above the position of the one end in the horizontal posture and above the other end opposite to the one end. A freezing vacuum drying device having a sloping device for any of the sloping postures in which the frozen particles deposited on the surface fall, wherein the freezing vacuum drying device is disposed above the heating / cooling shelf and has a lower opening at a lower end. A provided cylindrical cover, and the cover, A moving device that moves between a lower position where the particles fall inside the cover and accumulate on the surface of the heating / cooling shelf and an upper position above the lower position, and the cover includes the When in the lower position, when the heating / cooling shelf is in the horizontal posture, the lower opening faces the surface of the heating / cooling shelf, and when the heating / cooling shelf is in the inclined posture, the heating / cooling shelf is When the cover is in contact with the cover and the cover is in the upper position, the heating / cooling shelf is a freeze-drying apparatus that is in the inclined posture without contacting the cover.
The present invention is a freeze vacuum drying apparatus, wherein the inner surface of the cover is either a buffing or an electropolishing or both.
The present invention is a freeze-drying apparatus, wherein a beam supporting the shape of the cover is provided on the inner side of the cover, and an upper end surface of the beam is a mountain shape so that a ridge line is generated along the longitudinal direction of the beam. This is a freeze-drying apparatus formed by sharpening.

  The recovery rate of the frozen particles is improved in the freeze-drying apparatus.

Internal configuration diagram of the freeze vacuum drying apparatus of the present invention The figure for explaining the freeze vacuum drying device when the heating / cooling shelf is in the inclined posture Internal configuration diagram of conventional freeze-drying equipment

<Structure of freeze vacuum drying device>
The structure of the freeze vacuum drying apparatus of the present invention will be described. FIG. 1 is an internal configuration diagram of a freeze vacuum drying apparatus 10 of the present invention.
A freeze vacuum drying apparatus 10 according to the present invention includes a vacuum tank 11, a vacuum exhaust part 12 that evacuates the vacuum tank 11, an injector 14 that injects a raw material liquid into the vacuum tank 11, and a lower part of the injector 14. The heating / cooling shelf 16 disposed and a tilting device 18 that rotates the heating / cooling shelf 16 around a rotation axis 17 by a predetermined angle are provided.

  The injector 14 is disposed in the vacuum chamber 11 and is connected to a raw material liquid tank 15 in which the raw material liquid is stored. When the raw material liquid is supplied from the raw material liquid tank 15, the injector 14 is configured to be able to inject the supplied raw material liquid into the vacuum chamber 11.

  The raw material liquid contains a liquid component and a solid component such as a solute dissolved in the liquid component and a dispersion dispersed in the liquid component, and the raw material liquid injected into the vacuum chamber 11 evacuated is Before reaching the heating / cooling shelf 16, at least a part of the liquid component is evaporated and cooled, and at least a part of the liquid component is self-frozen to generate frozen particles containing the same solid component as the raw material liquid.

A cold trap 19 is disposed in the vacuum chamber 11, and the evaporated liquid component is attached to the cold trap 19 and collected.
The heating / cooling shelf 16 is formed in a flat plate shape here. When the posture of the heating / cooling shelf 16 is a horizontal posture in which the surface is horizontal, the generated frozen particles are deposited on the surface of the heating / cooling shelf 16.

  Inside the heating / cooling shelf 16, a flow path 16a through which a temperature-controlled heat medium flows is provided. When a heat medium is passed through the flow path 16a, the surface of the heating / cooling shelf 16 is heated or cooled to a predetermined temperature.

  When the surface of the heating / cooling shelf 16 is heated to a temperature lower than the melting temperature of the frozen particles while the frozen particles are accumulated on the surface of the heating / cooling shelf 16, the latent heat of vaporization is supplied to the frozen particles and the sublimation of the liquid component is accelerated. Is done. When the frozen particles contain an unfrozen portion, the unfrozen portion can be frozen by cooling the surface of the heating / cooling shelf 16 to a temperature lower than the freezing temperature.

Here, the tilting device 18 has a support shaft 18a and a hydraulic drive device 18b.
The support shaft 18a is vertically arranged below the heating / cooling shelf 16, and the lower end of the support shaft 18a penetrates the wall surface of the vacuum chamber 11 in an airtight manner, and is a hydraulic drive device 18b disposed outside the vacuum chamber 11. Is attached. The hydraulic drive device 18b is configured to transmit power by hydraulic pressure to the support shaft 18a and to move the support shaft 18a upward or downward.

The one rotation axis 17 is horizontally disposed at a position spaced in the horizontal direction with respect to the support shaft 18 a, here through the inside of the heating / cooling shelf 16.
When the support shaft 18a is raised by the hydraulic drive device 18b when the heating / cooling shelf 16 is in the horizontal posture, the upper end of the support shaft 18a pushes up the heating / cooling shelf 16 and the heating / cooling shelf 16 is The one end 16b of the heating / cooling shelf 16 is above the position of the one end 16b in the horizontal posture and above the other end 16c opposite to the one end 16b. It becomes an inclined posture where frozen particles deposited on the surface fall.

  In addition, when the support shaft 18a is lowered by the hydraulic drive device 18b when the heating / cooling shelf 16 is in the inclined posture, the heating / cooling shelf 16 rotates around the rotation axis 17 by a predetermined angle with reference to FIG. The surface of the heating / cooling shelf 16 is horizontal, and the generated frozen particles are deposited in a horizontal posture on the surface.

  In this embodiment, one rotation axis 17 is arranged at a position closer to the other end 16 c than the one end 16 b of the heating / cooling shelf 16, and the heating / cooling shelf 16 is arranged around the one rotation axis 17 at a predetermined angle. When rotating, the moving range of the other end 16c is made smaller than the moving range of the one end 16b. For this reason, when the heating / cooling shelf 16 is inclined, the size of the space required below the heating / cooling shelf 16 is not obstructed to move the one end 16b. Therefore, it is smaller than the space required above the heating / cooling shelf 16.

  Therefore, the space below the heating / cooling shelf 16 can be designed compactly. A space larger than the lower portion of the heating / cooling shelf 16 is required above the heating / cooling shelf 16, but a space of a predetermined size is provided between the injector 14 and the heating / cooling shelf 16 to generate frozen particles. It is provided in advance, and it is not necessary to further expand the space above the heating / cooling shelf 16.

Below the heating / cooling shelf 16, a collection unit that collects frozen particles dropped from the heating / cooling shelf 16 is arranged.
In the present embodiment, the recovery unit is provided with a recovery tank 32 disposed below the vacuum tank 11, and first and second openings 31a and 31b provided at one end and the other end, respectively, and the first opening 31a is a vacuum tank. 11 and a connection pipe 31 in which the second opening 31b is exposed in the collection tank 32, and a valve body 35 for switching between closing and opening of the second opening 31b.

A sub-vacuum exhaust unit 38 is connected to the collection tank 32 so that the inside of the collection tank 32 can be evacuated.
An annular valve seat 34 is fixed in close contact with the end of the connection pipe 31 inserted into the collection tank 32 so as to surround the second opening 31b. The valve seat 34 is, for example, a rubber O-ring.

The valve body 35 is disposed below the valve seat 34 and is configured to be able to rotate around a single auxiliary rotation axis 36 by a predetermined angle.
Referring to FIG. 1, when the valve body 35 is in close contact with the valve seat 34, the valve body 35 is rotated by a predetermined angle around one auxiliary rotation axis 36. With reference to FIG. The second opening 31 b is opened away from the valve seat 34.

  On the other hand, when the valve element 35 is separated from the valve seat 34 and the valve element 35 is rotated around the auxiliary rotation axis 36 by a predetermined angle, the surface of the valve element 35 is shown in FIG. The second opening 31b is closed by being pressed against the ring 34 and in close contact with the ring.

The first opening 31a is disposed below the other end 16c of the heating / cooling shelf 16, and the frozen particles falling from the surface of the heating / cooling shelf 16 fall inside the first opening 31a. .
When the valve body 35 is separated from the valve seat 34, the frozen particles that fall inside the connection pipe 31 through the first opening 31a move into the collection tank 32 through the second opening 31b.

  The freeze vacuum drying apparatus 10 of the present invention is disposed above the heating / cooling shelf 16 and has a cylindrical cover 21 provided with a lower opening 21b at the lower end and the cover 21, and the frozen particles descend inside the cover 21. And a moving device 22 that moves between a lower position accumulated on the surface of the heating / cooling shelf 16 and an upper position above the lower position.

Here, the cover 21 is made of stainless steel, and the inner surface of the cover 21 is electropolished to prevent the frozen particles from adhering.
The inner surface of the cover 21 is not limited to the case where it is electropolished as long as it is difficult for the frozen particles to adhere thereto, and may be buffed or both buffed and electropolished. .

The inner periphery of the lower opening 21 b is formed smaller than the outer periphery of the surface of the heating / cooling shelf 16.
When the heating / cooling shelf 16 is in a horizontal posture, the lower opening 21b at the lower position is closer to the surface of the heating / cooling shelf 16 than the lower opening 21b at the upper position, and faces the surface of the heating / cooling shelf 16. It is like that.

  Referring to FIG. 1, in this embodiment, an upper opening 21 a is provided at the upper end of the cover 21, and when the cover 21 is in the lower position, the injector 14 is configured to go outside the upper opening 21 a. However, it may be configured to enter inside.

  When the injector 14 goes out of the upper opening 21a when the cover 21 is in the lower position, the inner periphery of the upper opening 21a is formed as large as possible, the outer periphery of the upper end of the cover 21 and the inner periphery of the vacuum chamber 11 Is preferably as small as possible. This is because the generated frozen particles can be prevented from falling outside the heating / cooling shelf 16 through the gap between the outer periphery of the upper end of the cover 21 and the inner periphery of the vacuum chamber 11.

A beam 23 that holds the shape of the cover 21 is provided inside the cover 21, and one end of one or a plurality of hanging lines 24 is fixed to the beam 23.
The upper end surface of the beam 23 is formed in a mountain shape so that a ridge line is formed along the longitudinal direction of the beam 23, and the frozen particles that reach the upper end surface of the beam 23 slide down and accumulate on the upper end surface. It is supposed not to.

The other end of the suspension line 24 penetrates the ceiling of the vacuum chamber 11 in an airtight manner and is connected to a moving device 22 disposed outside the vacuum chamber 11.
The moving device 22 is a hydraulic hoist here, and when the suspension line 24 is wound up, the beam 23 and the cover 21 move together, and when the suspension line 24 is lowered, the beam 23 and the cover 21 are moved together. It is designed to move downward. The power source of the moving device 22 is not limited to hydraulic pressure, and compressed air or a motor may be used.

When the cover 21 is in the lower position, when the heating / cooling shelf 16 is in the horizontal posture, the lower opening 21b faces the surface of the heating / cooling shelf 16 and when the heating / cooling shelf 16 is in the inclined posture, the heating / cooling shelf 16 Is in contact with the cover 21.
On the other hand, when the cover 21 is in the upper position, the heating / cooling shelf 16 is inclined without contacting the cover 21.

<How to use freeze-drying equipment>
The freeze vacuum drying apparatus 10 has a control device 60, and the control device 60 is configured to perform the following steps.

(Preparation process)
Referring to FIG. 1, the inside of the vacuum chamber 11 is evacuated by the evacuation unit 12 to make a vacuum atmosphere. Thereafter, evacuation is continued and the vacuum atmosphere in the vacuum chamber 11 is maintained. Further, the recovery tank 32 is evacuated by the sub-evacuation unit 38 to make a vacuum atmosphere. Thereafter, evacuation is continued and the vacuum atmosphere in the collection tank 32 is maintained.
The valve body 35 is brought into close contact with the valve seat 34, the second opening 31 b of the connection pipe 31 is closed, and the internal space of the vacuum tank 11 and the internal space of the recovery tank 32 are shut off.

(Frozen particle production process)
A heating medium having a first temperature lower than the freezing temperature of the raw material liquid is caused to flow through the flow path 16 a inside the heating / cooling shelf 16 to cool the surface of the heating / cooling shelf 16.
The heating / cooling shelf 16 is brought into a horizontal posture by the tilting device 18. Subsequently, the cover 21 is disposed at a lower position by the moving device 22 so that the lower opening 21 b faces the surface of the heating / cooling shelf 16.

The raw material liquid is injected from the injector 14 into the evacuated vacuum chamber 11. The sprayed raw material liquid is cooled by evaporating at least a part of the liquid component before reaching the heating / cooling shelf 16 to generate frozen particles in which at least a part is frozen.
The evaporated liquid component adheres to the cold trap 19 and is collected.

  In the present embodiment, when the cover 21 is in the lower position, the injector 14 protrudes to the outside of the upper opening 21 a, but a gap between the outer periphery of the upper end of the cover 21 and the inner periphery of the vacuum chamber 11. Is made as small as possible, and the generated frozen particles fall inside the upper opening 21a.

The inner surface of the cover 21 is electropolished, and the frozen particles coming into contact with the inner surface of the cover 21 slide down without adhering.
The frozen particles falling inside the cover 21 reach the region facing the lower opening 21b in the surface of the heating / cooling shelf 16 in the horizontal posture and accumulate.

  Referring to FIG. 3, in the conventional freeze-drying apparatus 100, some of the frozen particles fall into the gap between the heating / cooling shelf 116 and the inner periphery of the vacuum chamber 111, so the recovery rate was 80%. On the other hand, referring to FIG. 1, in the freeze vacuum drying apparatus 10 of the present invention, the frozen particles fall inside the cover 21 and reach the surface of the heating / cooling shelf 16, so that the frozen particles are collected at a recovery rate of 95% or more. Can be recovered.

  The smaller the gap between the lower end of the cover 21 and the surface of the heating / cooling shelf 16, the better. The lower end of the cover 21 and the surface of the heating / cooling shelf 16 are in contact with each other, and it is more preferable that the gap is zero. The smaller the gap between the lower end of the cover 21 and the surface of the heating / cooling shelf 16, the more frozen particles spill outside the heating / cooling shelf 16 through the gap between the lower end of the cover 21 and the surface of the heating / cooling shelf 16. This is because it can be prevented.

  The surface of the heating / cooling shelf 16 is cooled to a first temperature lower than the freezing temperature of the raw material liquid. If the frozen particles accumulated include an unfrozen portion, the surface is further cooled to The frozen part is also frozen.

  After freezing the frozen particles, a heating medium having a second temperature higher than the first temperature and lower than the melting temperature of the frozen particles is caused to flow through the flow path 16a inside the heating / cooling shelf 16 to thereby heat and cool the shelf 16. Heat the surface. The latent heat of vaporization is supplied to the frozen particles from the heated heating / cooling shelf 16, the sublimation of the liquid component is accelerated, and the drying time of the frozen particles is shortened.

When the frozen particles are dried, dry particles are produced.
After finishing the drying of the frozen particles, the cover 21 is moved to the upper position by the moving device 22 with reference to FIG.

(Dry particle export process)
The valve body 35 is separated from the valve seat 34, the second opening 31 b is opened, and the internal space of the vacuum tank 11 and the internal space of the recovery tank 32 are connected.

The heating / cooling shelf 16 is brought into an inclined posture by the inclination device 18. The heating / cooling shelf 16 is arranged in an upper position in advance, and the heating / cooling shelf 16 is inclined without contacting the cover 21.
The dry particles deposited on the surface of the heating / cooling shelf 16 slide down, fall inside the first opening 31a, pass through the inside of the connection pipe 31, and move from the second opening 31b into the recovery tank 32.

After the dried particles move into the recovery tank 32, the valve body 35 is brought into close contact with the valve seat 34, the second opening 31b is closed, and the internal space of the vacuum tank 11 and the internal space of the recovery tank 32 are shut off.
After blocking the internal space of the vacuum chamber 11 and the internal space of the recovery tank 32, the above-described frozen particle generation step is performed in the vacuum chamber 11.

  On the other hand, after shutting off the internal space of the vacuum tank 11 and the internal space of the recovery tank 32, in the recovery tank 32, the vacuum evacuation by the sub-vacuum exhaust unit 38 is stopped, and the inside of the recovery tank 32 is opened to the atmosphere, or A compressed gas is caused to flow into the collection tank 32 from a gas introduction unit (not shown), and the dried particles are carried out of the collection tank 32. Next, evacuation by the sub evacuation unit 38 is resumed, and the inside of the collection tank 32 is made a vacuum atmosphere. After the frozen particle generation process in the vacuum chamber 11 is completed, the above-described dry particle unloading process is performed.

DESCRIPTION OF SYMBOLS 10 ... Freezing vacuum dryer 11 ... Vacuum tank 12 ... Vacuum exhaust part 14 ... Injector 16 ... Heating / cooling shelf 17 ... One axis of rotation 18 ... Inclination device 21 ... Cover 21b ... Lower opening 22 …… Moving device 23 …… Beam

Claims (3)

A vacuum chamber;
An evacuation unit for evacuating the vacuum chamber;
An injector for injecting a raw material liquid into the evacuated vacuum chamber to generate frozen particles;
A heating and cooling shelf disposed below the injector;
The heating / cooling shelf is rotated by a predetermined angle around one rotation axis, the surface of the heating / cooling shelf is horizontal, and the horizontal posture in which the generated frozen particles accumulate on the surface, and the heating / cooling shelf One end of the horizontal position is above the position of the one end in the horizontal position and is positioned above the other end opposite to the one end, and an inclined position in which the frozen particles deposited on the surface fall A tilting device to either
A freeze-drying apparatus comprising:
A cylindrical cover disposed above the heating and cooling shelf and provided with a lower opening at the lower end;
A moving device that moves the cover between a lower position where the frozen particles fall inside the cover and accumulate on the surface of the heating / cooling shelf, and an upper position above the lower position;
Have
When the cover is in the lower position, when the heating / cooling shelf is in the horizontal posture, the lower opening faces the surface of the heating / cooling shelf, and when the heating / cooling shelf is in the inclined posture, The heating / cooling shelf comes into contact with the cover,
When the cover is in the upper position, the heating / cooling shelf is placed in the inclined posture without coming into contact with the cover.   The freeze-drying apparatus according to claim 1, wherein an inner surface of the cover is subjected to either or both of buffing and electrolytic polishing. Inside the cover is provided a beam that supports the shape of the cover,
The freeze vacuum drying apparatus according to claim 1, wherein the upper end surface of the beam is formed to be sharpened in a mountain shape so that a ridge line is formed along a longitudinal direction of the beam.

Images