JP2006297243A - Vacuum spray dryer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum spray dryer capable of avoiding the modification, decomposition or deterioration of the component in a solute and capable of reducing a manufacturing cost or a running cost. <P>SOLUTION: In the vacuum spray dryer equipped with a vacuum chamber 1, an atomizer 2 for atomizing a liquid to be dried to form spray liquid droplets F and the heating means 3 attached to the vacuum chamber 1 and constituted so as to dry the spray liquid droplets F under a vacuum atmosphere, the atomizer 2 is equipped with an ultrasonic atomizing device for atomizing the liquid to be dried and a dust collector for separating fine particles from the air introduced from the outside. The atomizer 2 is provided outside the vacuum chamber 1 and the atomizer spray liquid droplets F are sucked in the vacuum chamber 1 through a supply pipe 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a spray dryer.

2. Description of the Related Art Conventionally, as a device for producing a dried product from a solution or a slurry solution, there is a spray dryer (a spray dryer) that produces a dried product under high temperature and pressure conditions (for example, see Patent Document 1).
JP-A-8-155203

However, since the conventional spray dryer is dried in a high temperature atmosphere of 150 to 250 ° C., the temperature of the solute itself dissolved in the solution rises. For example, a heat-sensitive component (thermally decomposable component) in pharmaceuticals and foods Alternatively, the heat deterioration component) is denatured, decomposed or deteriorated.
In addition, in order to avoid denaturation, decomposition, degradation, etc. of the thermally decomposable component or the thermally deteriorated component, there is a device that is dried at a low temperature of −180 to −10 ° C. (freeze drying). There is a problem of yield and stability such that it is difficult to obtain a product, and this freeze-drying method requires the installation cost of the freezing treatment equipment required for preliminary freezing, and the running time is enormous due to the long drying time There is also a problem.
Furthermore, in the vacuum freeze-drying method of drying under a high vacuum of about 50 to 400 hPa at about 35 ° C. or less, there is a problem that a running cost is required because a lot of liquid nitrogen required for freezing or a refrigerant instead of it is used.
Accordingly, a main problem of the present invention is to provide a spray dryer that can avoid modification, decomposition, degradation, etc. of components in a solute and can reduce production cost and running cost.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
The invention described in claim 1 includes a vacuum chamber, an atomizer that atomizes a liquid to be dried to generate spray droplets, and a heating unit attached to the vacuum chamber, and the spray droplets are formed in a vacuum atmosphere. A vacuum spray dryer for drying, wherein the atomizer includes an ultrasonic atomizer that atomizes a liquid to be dried, and a dust collector that separates fine particles from air introduced from the outside. An atomized droplet provided outside the vacuum chamber and configured to be atomized is sucked into the vacuum chamber via a supply pipe.

(Function and effect)
In the vacuum spray dryer according to the present invention, the inside of the chamber is heated in a vacuum atmosphere by a heating means to dry the spray droplets, so that the amount of energy required for drying can be suppressed compared to vacuum freeze drying. .
The atomizer includes an ultrasonic atomizer that atomizes the liquid to be dried, and a dust collector that separates fine particles from air introduced from the outside. The atomizer is provided outside the vacuum chamber and atomized. The spray droplets can be sucked into the vacuum chamber through the supply pipe, so that extra splashes other than the spray droplets can be prevented from entering the vacuum chamber. Therefore, the sprayed droplets are appropriately prevented from agglomerating, the particle size distribution can be made uniform, and the generation of a large particle size can be prevented. In addition, the dried product can be sufficiently dried, and problems in subsequent processes and a reduction in the recovery rate of the dried product can be prevented.

<Invention of Claim 2>
The dust collector of the present invention includes a filter dust collector, and a cleaning dust collector that introduces air that has passed through the filter dust collector into the liquid to further separate fine particles. The vacuum spray dryer according to claim 1, wherein the vacuum spray dryer is configured as described above.

<Invention of Claim 3>
A third aspect of the present invention is the vacuum spray dryer according to the first or second aspect, wherein the dust collector is configured to include at least a HEPA filter or a ULPA filter.

(Function and effect)
The dust collector is configured to include a filter dust collector and a cleaning dust collector that introduces air that has passed through the filter dust collector into the liquid and further separates the fine particles. Foreign substances and allergens can be removed, and contamination can be prevented.
Further, the dust collector can be configured to include at least a HEPA filter or a ULPA filter.

<Invention of Claim 4>
According to a fourth aspect of the present invention, there is provided the vacuum spray dryer according to any one of the first to third aspects, wherein a rotary feeder is provided at a lower portion of the vacuum chamber, and dried material is discharged from the rotary feeder. It is.

(Function and effect)
A rotary feeder is provided in the lower part of the vacuum chamber, and the dried product is discharged from the rotary feeder, so that the dried product can be controlled while suppressing fluctuations in the degree of vacuum when the dried product is discharged compared to a slide gate or the like. Can be continuously discharged, so that a dried product can be efficiently produced, and the dried product can be efficiently conveyed to the next step.

<Invention of Claim 5>
A fifth aspect of the present invention is the vacuum spray dryer according to any one of the first to fourth aspects, wherein a vacuum exhaust pipe connected to a vacuum pump is provided in an upper part of the vacuum chamber.

(Function and effect)
By providing an evacuation pipe connected to a vacuum pump at the upper part of the vacuum chamber, there is no possibility of sucking dry matter that drops and deposits in the vacuum chamber. In order to enhance the effect of preventing the suction of dry matter, a slit of a labyrinth structure or a sintered metal filter may be attached to the inlet of the vacuum exhaust pipe.

<Invention of Claim 6>
A sixth aspect of the present invention is the vacuum spray dryer according to any one of the first to fifth aspects, wherein a lining for preventing adhesion of dry matter is attached to the inner periphery of the vacuum chamber.

(Function and effect)
By attaching a lining to prevent the adhesion of dry matter to the inner circumference of the vacuum chamber, the dry matter falls down without adhering the dry matter to the inner peripheral surface of the vacuum chamber, and the dry matter recovery efficiency Can be improved. In addition, it becomes easy to clean the inside of the vacuum chamber when the dried product to be manufactured is switched, and further contamination can be prevented.

<Invention of Claim 7>
The invention according to claim 7 is configured such that the inside of the vacuum chamber is maintained at −2.7 × 10 ⁻³ to −5.4 × 10 ⁻³ (MPa abs), 20 to 80 ° C. during operation. A vacuum spray dryer according to any one of claims 1 to 6.

(Function and effect)
Since the spray dryer of the conventional example is dried in a high temperature atmosphere of 150 to 250 ° C., the temperature of the solute dissolved in the solution rises. For example, a heat-sensitive component in a medicine or food is denatured, decomposed or deteriorated, etc. However, since the temperature in the chamber is 20 to 80 ° C., there is no denaturation, decomposition, degradation, etc., and physiological activity is not lost even in pharmaceutical products.
Moreover, when the pressure in the chamber is −2.7 × 10 ⁻³ to −5.4 × 10 ⁻³ (MPa abs), drying at a low temperature can be performed quickly and efficiently.

  According to the present invention, advantages such as avoidance of modification, decomposition, degradation, etc. of components in a solute and reduction of production cost and running cost can be brought about.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 is a schematic view of a vacuum spray dryer according to the present invention, FIG. 2 is an embodiment of an atomizer, and FIG. 3 is another embodiment of the atomizer.
The vacuum spray dryer according to the present invention includes a vacuum chamber 1, an atomizer 2 that atomizes a liquid to be dried to generate spray droplets, a heating unit 3 attached to a side surface (outer peripheral surface) of the vacuum chamber 1, And a rotary feeder 4 attached to the lower part of the vacuum chamber 1.

  The vacuum chamber 1 has a substantially cylindrical shape. As will be described later, a spray droplet supply pipe 5 for supplying the spray droplet F atomized by the atomizer 2 is attached to the upper end portion, and the lower end portion has a lower end portion. A rotary feeder 4 for discharging the dried material falling downward is attached. A supply valve 5 </ b> A is attached to the spray droplet supply pipe 5. A vacuum exhaust pipe 6 is attached to the upper end, and is connected to a vacuum pump 6B via an exhaust valve 6A. By operating this vacuum pump 6B, the inside of the chamber can be kept in a vacuum state. It has become. Further, since the vacuum exhaust pipe 6 is attached to the upper end portion of the vacuum chamber 1, there is no possibility of sucking dry matter accumulated in the lower portion of the vacuum chamber 1. The installation position of the vacuum exhaust pipe 6 is not limited to the upper end portion of the vacuum chamber 1, and may be any position as long as it does not suck in dry matter. For example, the upper position of the vacuum chamber 1 may be used. Further, in order to enhance the effect of preventing the suction of dried matter, a slit (not shown) having a labyrinth structure, a sintered metal filter (not shown), or the like may be attached to the inlet of the vacuum exhaust pipe 6.

  The spray droplet F atomized by the atomizer 2 is dried into a powdery powder-like dried product, but this dried product adheres to the inner peripheral surface of the vacuum chamber 1 and does not fall downward. There is a fear. In order to prevent this, it is preferable to attach a lining (not shown) for preventing adhesion of dry matter to the inner periphery of the vacuum chamber 1. By attaching the lining, the dried product can be dropped downward without adhering the dried product to the inner peripheral surface of the vacuum chamber, and the recovery efficiency of the dried product can be improved. As a material for the lining, carbon fiber or the like for preventing charging can be considered. In place of the lining attachment, although not shown, air containing negative ions generated by the negative ion generator is blown from the upper part of the vacuum chamber 1 downward along the inner periphery. You may prevent electrification and may prevent adhesion of dry matter.

In operation, the vacuum chamber 1 has a medium vacuum that is close to atmospheric pressure in comparison with conventional high-vacuum vacuum freeze-drying, -2.7 × 10 ⁻³ to −5.4 × 10 ⁻³ (MPa abs). The temperature is kept at 20 to 80 ° C., which is lower than that of a conventional high temperature (about 180 to 250 ° C.) spray dryer. That is, the conventional spray dryer performs drying in a high-temperature atmosphere of 150 to 250 ° C., so that the temperature of the solute itself dissolved in the solution rises. Alternatively, the heat-degraded component) may be denatured, decomposed or deteriorated, but since the temperature in the chamber is 20 to 80 ° C., the denaturation, decomposition or deterioration does not occur, and physiological activity is lost even in pharmaceutical products. There is nothing. Moreover, compared with freeze-drying, drying time is short (freeze-drying: 16 to 22 hours, the present invention: about 10 seconds), and freeze-drying requires enormous energy for sublimation of the frozen material, but the vacuum spray according to the present invention. According to the drying method using a dryer, a large amount of energy is not required (in order to recover 1 kg of dried material from the same substance, for example, freeze drying requires 2.5 × 10 ⁹ J of energy. Then, energy of about 3.6 × 10 ⁸ J is sufficient). Furthermore, according to the present invention, it is not necessary to freeze the pretreatment necessary for lyophilization, and further, it is not necessary to install a freezing apparatus.

  In order to manage the pressure and temperature, a thermometer 7 for measuring the temperature inside the chamber is attached to the upper end of the vacuum chamber 1, and pressure gauges 8 and 8 for measuring the pressure inside the chamber are attached to the side surfaces. The temperature and pressure are displayed on a display monitor (not shown) connected to the cables 7A and 8A. In addition, about the installation location and installation number of the thermometer 7 and the pressure gauge 8, it can change arbitrarily.

FIG. 2 shows an embodiment of an atomizer. The atomizer shown in FIG. 2 includes an ultrasonic atomizing device 2A for atomizing a liquid to be dried, and air for conveying the spray droplets atomized by the ultrasonic atomizing device 2A into the vacuum chamber 1. And a dust collecting device 2B for separating fine particles as foreign matter from the mist, and the atomized spray droplets are conveyed into the vacuum chamber 1 through the spray droplet supply pipe 5.
The ultrasonic atomizer 2A includes a tank 21 that stores a liquid to be dried, an ultrasonic vibrator 22 that is attached to a lower portion of the tank 21 and irradiates the liquid to be dried in the tank 21 with ultrasonic waves, and the ultrasonic wave. And an oscillator 23 for supplying an oscillation output to the vibrator 22. A control device (not shown) is attached to the oscillator 23. When power is cut off by a power switch (not shown), the output of the oscillator 23 is stopped, and when the power switch is turned on, the control device An output for driving the oscillator 23 is provided. Then, the ultrasonic vibrator 22 is driven by the output of the oscillator 23 so that the liquid to be dried is irradiated with ultrasonic waves, and the liquid to be dried is atomized. As this ultrasonic atomizer 2A, for example, an ultrasonic atomizer unit (HM-2412) manufactured by Honda Electronics Co., Ltd. can be used. In addition, it can replace with this ultrasonic atomizer, and the apparatus (For example, 8700-48 by the Sono-Tek company) using the ultrasonic spray nozzle which can control flow volume with the conveyance speed of a to-be-dried liquid can also be used. .

  A liquid to be processed supply pipe 27 is attached to the upper part of the tank 21, and the liquid to be dried is supplied from the liquid supply pipe 27 to be processed into the tank 21. A spray droplet supply pipe 5 is attached to the upper part of the tank 21, and the spray droplets F are supplied into the tank 21 from the spray droplet supply pipe 5.

  The tank 21 that stores the liquid to be dried can be provided with a mechanism that facilitates cleaning (for example, a cleaning ball and a cleaning ring) and a mechanism that facilitates discharge of the liquid (for example, a valve and a pump).

  Although not shown, the tank 21 that stores the liquid to be dried is supplied with a liquid to be processed from the liquid supply pipe 27 to be processed by a mechanism that enables unattended operation (for example, a signal from a liquid level gauge). For example, a mechanism for controlling the pump to keep the liquid level constant may be provided.

  The dust collector 2B is a filter dust collector 24 that separates particulates that are foreign substances from the air introduced from the outside air, and cleaning that introduces air that has passed through the filter dust collector 24 into the liquid and further separates the particulates. A dust collecting unit 25.

  A known bag filter or air filter can be used for the filter dust collecting unit 24. As the material of the bag filter, natural fibers such as cotton and paper, chemical fibers such as nylon and tetron, glass fibers, graphite fibers and the like can be used. As the materials of the air filter, glass fibers, cellulose, nylon fibers and the like are used. be able to. The cleaning dust collection unit 25 stores liquid as a collection medium in the cleaning tank, and further separates fine particles (for example, mist) from the air that has passed through the filter dust collection unit 24. Furthermore, the cleaning dust collecting unit 25 may be provided with an air diffusion mechanism (for example, a porous metal filter or a porous ceramic) for increasing the contact efficiency between the fine particles and the collection medium.

  Air supply pipes 26 and 26 are connected to the bottom and top of the cleaning tank, and the air that has passed through the filter dust collecting unit 24 is transported from the bottom of the cleaning tank and is cleaned from the top by the liquid in the cleaning tank. Air is discharged, and this air is supplied into the tank 21 of the ultrasonic atomizer 2A. The liquid stored in the cleaning tank can use water such as distilled water, but it suddenly boils and flows into the tank 21 of the ultrasonic atomizer 2 </ b> A via the air supply pipe 26. In consideration of the possibility, it is preferable to use the same liquid as the liquid to be dried. The dust collector 2B collects fine particles by the filter dust collecting unit 24 and the cleaning dust collecting unit 25 in a double manner, thereby making it possible to remove foreign matters and allergens in the introduced air more reliably. Further, by providing the cleaning dust collecting unit 25, the filter dust collecting unit 24 also has a risk hedging function of preventing contamination when trouble occurs.

  The atomizer 2 utilizes the fact that the vacuum chamber 1 has a negative pressure compared to the atmospheric pressure, introduces air from the atmosphere via the dust collector 2B, and atomizes the liquid to be dried. The droplet F is supplied into the vacuum chamber 1 by this air through the spray droplet supply pipe 5. In the present invention, the ultrasonic atomizer 2A is provided in the vacuum chamber 1 to atomize the liquid to be dried in the chamber, but the liquid to be dried is atomized outside the chamber, and the spray droplet supply pipe 5 is provided. In this way, the spray droplets F are supplied into the vacuum chamber 1 to prevent extra splashes other than the spray droplets F from entering the chamber. Therefore, the sprayed droplets are appropriately prevented from agglomerating, the particle size distribution can be made uniform, and the generation of a large particle size can be prevented. In addition, the dried product can be sufficiently dried, and problems in subsequent processes and a reduction in the recovery rate of the dried product can be prevented.

  Further, when the outlet of the spray droplet supply pipe 5 in the chamber and the inlet of the vacuum exhaust pipe 6 described above are close to each other and the spray droplet F is sucked into the vacuum exhaust pipe, there is an obstacle between them. A plate (not shown) may be provided and adjusted so that the spray droplets F are not sucked.

  The dust collector 2B according to the present invention is not limited to the configuration including the filter dust collector 24 and the cleaning dust collector 25, and the filter dust collector 24 or the cleaning collector according to the properties of the air to be introduced. The thing provided only with the dust part 25 may be sufficient. As another embodiment, the atomizer shown in FIG. 3 may be applied when the dust collector 2B is only the filter dust collector 28 and introduces air from inside a clean room, for example. This filter dust collecting unit 28 is a filter showing a dust collection rate of 99.9995% or more when the filter is passed once through 1.5 μm particles as test dust in accordance with the performance capability test method described in JIS B9908 or B9927. A HEPA filter or a ULPA filter is suitable. The other configuration is the same as the above configuration, and the description is omitted. In addition, you may use a HEPA filter, a ULPA filter, etc. as the filter dust collection part 24 in the atomizer shown by FIG.

  As shown in FIG. 1, a heating means 3 and a heat insulating material 9 covering the heating means 3 are attached to the outer peripheral surface of the substantially cylindrical vacuum chamber 1. As the heating means 3, a rubber heater (silicon rubber heater) that is highly efficient in a limited space and that can be used stably for a long time with little change over time is used. In the embodiment shown in FIG. 1, the wire is wound around the upper and lower portions of the vacuum chamber 1. The heating means 3 is not limited to a rubber heater, and may be a heating coil or a hot water pipe that circulates hot water in a tube. The heat insulating material 9 covers substantially the entire outer peripheral surface of the vacuum chamber 1, and glass wool or the like can be used as the material.

  As shown in FIG. 1, a rotary feeder 4 is provided at the lower part of the vacuum chamber 1, so that dry matter can be discharged to the outside while keeping the inside of the chamber in a vacuum state. It has become. By using the rotary feeder 4, it is possible to continuously discharge the dried product while suppressing fluctuations in the degree of vacuum when discharging the dried product, compared to a slide gate, etc., and efficiently transport the dried product to the next process. can do. And the dried material discharged | emitted from the rotary feeder 4 is conveyed by the following process by conveyance means, such as a belt conveyor.

It is a schematic diagram of the vacuum spray dryer concerning the present invention. It is one Example of an atomizer. It is another Example of an atomizer.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vacuum chamber, 2 ... Atomizer, 2A ... Ultrasonic atomizer, 2B ... Dust collector, 3 ... Heating means, 4 ... Rotary feeder, 5 ... Spray droplet supply pipe, 5A ... Supply valve, 6 ... Vacuum exhaust Pipe, 6A ... Exhaust valve, 6B ... Vacuum pump, 7 ... Thermometer, 7A ... Cable, 8 ... Pressure gauge, 8A ... Cable, 9 ... Insulating material, 21 ... Tank, 22 ... Ultrasonic transducer, 23 ... Oscillator, 24 ... filter dust collecting unit, 25 ... cleaning dust collecting unit, 26 ... air supply pipe, 27 ... processed liquid supply pipe, 28 ... filter dust collecting part, F ... spray droplet.

Claims (7)

A vacuum spray dryer that includes a vacuum chamber, an atomizer that atomizes a liquid to be dried to generate spray droplets, and a heating means attached to the vacuum chamber, and that performs a drying process on the spray droplets in a vacuum atmosphere. And
The atomizer includes an ultrasonic atomizer that atomizes a liquid to be dried, and a dust collector that separates fine particles from air introduced from the outside, and the atomizer is provided outside the vacuum chamber.
The atomized spray droplet is configured to be sucked into the vacuum chamber through the supply pipe.
A vacuum spray dryer characterized by this.   The dust collector is configured to include a filter dust collector, and a cleaning dust collector that introduces air that has passed through the filter dust collector into the liquid to further separate fine particles. The vacuum spray dryer according to 1.   The vacuum spray dryer according to claim 1 or 2, wherein the dust collector is configured to include at least a HEPA filter or a ULPA filter.   The vacuum spray dryer according to any one of claims 1 to 3, wherein a rotary feeder is provided at a lower portion of the vacuum chamber, and a dried product is discharged from the rotary feeder.   The vacuum spray dryer according to any one of claims 1 to 4, wherein a vacuum exhaust pipe connected to a vacuum pump is provided in an upper part of the vacuum chamber.   The vacuum spray dryer according to any one of claims 1 to 5, wherein a lining for preventing adhesion of dry matter is attached to an inner periphery of the vacuum chamber. The inside of the vacuum chamber is configured to be maintained at −2.7 × 10 ⁻³ to −5.4 × 10 ⁻³ (MPa abs) and 20 to 80 ° C. during operation. A vacuum spray dryer according to any one of the preceding claims.

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