JPH0248027Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a vacuum powder granulation method that sprays a liquid onto the surface of powder or granules under vacuum and is used for forming coated products or granulated products. This invention relates to an improvement of a body treatment device.

[Conventional technology]

Vacuum powder processing equipment generally connects a pressure reduction means and a spraying means to a closed container, and sprays a liquid on the powder and granules stored in the closed container while mixing and agitating them under vacuum to coat or granulate them. After that, drying treatment is performed.

As the heating means, for example, there is a heating medium circulation method proposed by the present person. This has a double structure in which the main body of the sealed container and the wall of the door are each double-walled, a heat medium passage is formed in each wall, and a flexible tube is provided at the threaded part between the main body and the door to communicate the two passages. At the same time, a pump and a heater are connected between the inlet and outlet of both passages, and hot water is circulated through the heat medium passage to heat and dry the powder (Japanese Patent Laid-Open No. 177167/1983). (see official bulletin).

Further, as another heating means, there is a microwave heating method. This process involves feeding powder into a stationary kneading machine or granulating machine, granulating it while spraying water as a binder, and then using a microwave heating machine consisting of a microwave oscillator and a waveguide. It irradiates waves, and ordinary microwave heating machines are used as is. That is, since the container of the kneading machine or granulator here is of a fixed type, the waveguide of a normal microwave heating machine is directly connected to it (Japanese Patent Laid-Open No. 59-26133).
(see publication).

[The problem that the idea aims to solve]

Among the heating means used in powder and granular material processing equipment, those that circulate hot water, steam, etc. using the heat medium circulation method described above have sufficient heat transfer efficiency and are effective for normal heating and drying of powder and granules. It is something.

However, this heating medium circulation system has a problem in that in the case of tablet-like particles with large particles, the contact area with the inner surface of the closed container is reduced, resulting in low heat transfer efficiency and unsuitable for mass production.

On the other hand, the microwave heating means described above can uniformly heat not only powders and granules but also tablets with large particle sizes. Therefore, if the container itself is fixed, such as the above-mentioned kneading machine or granulator, the waveguide of a normal microwave heating machine can be connected as is, so microwave heating means is an extremely effective means. It is.

However, it is difficult to use the above-mentioned microwave heating means in a powder processing apparatus that processes the sealed container itself while rotating it. This is because installing a microwave oscillator in a sealed container requires the introduction of a high voltage (e.g. 15,000V), cooling means for the oscillator, and the possibility that spray liquid or powder may adhere to the surface of the oscillation tube and burn it.
This is because there are difficult problems such as it falling and adhering to the product at the bottom.

Therefore, it is conceivable to provide a microwave oscillation device outside the container, but this would require providing a waveguide (diameter 109.2 mm x 54.6 mm) to guide the microwaves into the sealed container. However, in small powder processing equipment, it is impossible to install a waveguide separately from the ventilation duct due to its relationship with the bearing, and problems arise with sealing materials and rotary pipe joints to ensure vacuum. .

Therefore, those skilled in the art would at least once have thought of using a ventilation duct communicating from the outside into the sealed container as a waveguide. However, conventional technical knowledge requires that the inner surface of the waveguide be polished to a mirror-like surface.

However, even after passing through the filter, some of the fine powder still adheres to the inner surface of the ventilation duct. To solve this problem, it is possible to use a high-density filter, but as the mesh becomes smaller in a given area, the pressure drop increases, so there is a limit for dry operation.

Therefore, it is considered technically impossible to use a ventilation duct as a waveguide, and there is currently no device of this kind that can serve both purposes.

The present invention is an attempt to solve the problems of the above-mentioned conventional powder processing apparatus. In other words, the purpose is to prevent fine powder from adhering to the inside of the ventilation duct as much as possible while providing sufficient ventilation to ensure a vacuum inside the closed container, and to efficiently irradiate the inside of the closed container with microwaves. By doing so, it is possible to use an efficient microwave heating means even in a small-sized powder processing apparatus in which a closed container itself rotates and performs continuous processing.

Structure of the invention [Means for solving the problem] The vacuum powder processing apparatus according to the invention includes a closed container 2, a pressure reducing means 3, a spraying means 5, and a microwave heating means 4, the closed container 2 is a bearing tube 24 protruding from the rear wall.
is rotatably supported on the machine base 1 and connected to a rotary drive device 25, and the pressure reducing means 3 inserts a ventilation duct 31 into the bearing sleeve 24, and connects one end of the ventilation duct 31 to the closed container 2. The other end is connected to an external exhaust pump 37.
The spray means 5 includes a spray nozzle 52 in the closed container 2.
The microwave heating means 4 is connected to the ventilation duct 31.
also serves as a waveguide, and the microwave oscillator 42
is provided at the rear end of the ventilation duct 31 via a partition plate 41, and an opening 32 is provided downward at the front end of the ventilation duct 31 in the closed container 2, and at least both sides covering the other parts are provided. Punching plate 33
The opening 32 and the outer periphery of the punching plate 33 are surrounded by a filter cloth 34 for a filter.

[Effect]

The operating state of the vacuum powder processing apparatus according to the present invention is as follows.

(i) Put the powder or granular material as a raw material into the closed container 2 and seal it, and after activating the pressure reducing means 3 to reduce the pressure inside the closed container 2, operate the rotary drive device 25,
And the microwave heating means 4 and the spraying means 5 are activated.

With this, the powder and granular material in the lower part of the closed container 2 is sprayed with liquid by the spraying means 5, and is stirred as the closed container 2 rotates.
Granulation or coating is performed, and drying is performed by heating by microwave heating means 4 under reduced pressure by pressure reducing means 3.

(ii) In the above case, the ventilation duct 31 also serves as a waveguide, and the microwave heating means 4 is used as the heating means of the vacuum powder processing apparatus of the present invention.

Therefore, although it is a small powder processing device in which the closed container 2 itself rotates, microwave heating means 4 is used as the heating means, and it is possible to process not only powder and granules but also large particles such as tablets with thermal efficiency. Can be heated and dried well.

(iii) Furthermore, a downward opening 32 is provided at the front end of the ventilation duct 31 in the closed container 2, and punching plates 33 are formed on at least both sides that cover the other portions.

Therefore, the microwaves guided into the closed container 2 using the ventilation duct 31 as a waveguide are reflected by the punching plate 33 and irradiated from the opening 32 opened downward. Since the granular material is rotated and stirred at the lower part of the closed container 2, the microwave is efficiently irradiated onto the granular material without irradiating unnecessary parts.

(iv) Furthermore, the filter cloth 34 for the filter surrounds not only the opening 32 but also the outer periphery of the punching plate 33 other than that.

Therefore, the microwave is transmitted through the opening 3 as described above.
Although the air is irradiated only from the opening 32, air intake for reducing the pressure is performed not only from the opening 32 but also from a large number of holes in the punching plate 33 in other parts. Therefore, the effective area of the filter cloth 34 for the filter is greatly expanded, and a filter cloth 34 for the filter with a small mesh can be used. Therefore, exhaust is performed with reasonable force,
Very little powder passes through the filter cloth 34, and the ventilation duct 31 also serves as a waveguide.

〔Example〕

FIG. 1 shows an embodiment of the vacuum powder processing apparatus according to the present invention, in which the sealed container 2 has a raw material input port 21 with a hatch-shaped opening/closing door 22 on the front, and a part of the circumference that can be opened/closed. It has a horizontally oriented short cylindrical shape and is provided with an outlet 23.

A bearing cylinder 24 whose front end communicates with the inside of the container 2 is protruded from the center of the rear surface of the closed container 2, and the bearing cylinder 24 is rotatably supported by the bearing part 11 of the machine base 1.

Inside the bearing tube 24, the front portion is attached to the bearing tube 2.
4 is supported via a sealing material, and a fixed cylinder 12 whose rear part is fixed to the machine base 1 is provided, and the fixed cylinder 12
A ventilation duct 31 forming a part of the pressure reducing means 3 is provided so as to penetrate through the fixed cylinder 12 and the ventilation duct 3.
A sealing material is applied between 1 and 1.

The ventilation duct 31 has a front end protruding almost to the center of the closed container 2, and a rear part is branched to form an exhaust port 35 having a punching plate 38, which is connected to an exhaust pump 37 via an exhaust pipe 36. The pressure reducing means 3 is configured by

The ventilation duct 31 also serves as a microwave waveguide as the microwave heating means 4, and a glass plate 4 as a partition plate is provided at the rear end of the ventilation duct 31.
1, or a microwave oscillator 42 is provided via a Teflon plate, and an opening 32 is provided downward at the front end of the ventilation duct 31 in the sealed container 2, and the front, top, and both sides cover the other parts. The surface is made up of a punching plate 33.

The opening 3 at the front end of the ventilation duct 31
2 and the punching plate 33 are surrounded by a filter cloth 34 for a filter.

The spraying means 5 is provided with a flow pipe 51 that penetrates the fixed cylinder 12, the tip of which is introduced into the closed container 2, a nozzle 52 with a variable diameter is attached, and the rear end is injected with liquid through a pump 53. It is connected to a tank 54.

In the figure, 6 indicates a temperature sensor inside the closed container.

Effects of the Invention As is clear from the above, the vacuum powder/granular material processing apparatus according to the present invention ensures that hardly any fine powder adheres to the inner surface of the ventilation duct while sufficiently evacuating the airtight container to ensure a vacuum. Moreover, microwaves can be efficiently irradiated inside the closed container. As a result, even though the powder processing equipment is small and the sealed container itself rotates, microwave heating means can be used efficiently, and large quantities of tablet-like particles can be processed. .

In other words, in conventional powder processing equipment that circulates hot water, steam, etc. using a heating medium circulation method as a heating means, when the particles are large in size and are in the form of tablets, the contact area with the inner surface of the closed container is small; It had low heat transfer efficiency and was unsuitable for mass production. Furthermore, if the processing container itself is of a fixed type, the waveguide of an ordinary microwave heating machine can be directly connected to the microwave heating means, and the microwave heating means is an extremely effective means.

However, in small powder processing equipment that processes while rotating the sealed container itself, there are many technical difficulties in installing a microwave oscillation device both inside and outside the sealed container. There were no methods using heating means.

In contrast, in the vacuum powder processing apparatus of the present invention, as described above, the front end of the ventilation duct in the closed container is provided with an opening facing downward, and at least both sides covering the other parts are punched. It is composed of a plate, and the opening and the punching plate are surrounded by a filter cloth for a filter.

As a result, the microwave is reflected by the punching plate and irradiated only downward from the opening, but since the powder and granules are rotated and stirred at the bottom of the container, the microwave is efficiently applied only to the areas where it is needed. Can be irradiated well.

Moreover, since the effective area of the filter cloth is greatly expanded beyond just the opening, it is possible to use a filter cloth with a small mesh. Therefore, the amount of fine powder passing through the filter cloth can be reduced and the inside of the ventilation duct can be kept clean, so that it can also be used as a waveguide.

Therefore, even though the powder processing equipment is small and the closed container itself rotates, microwave heating means can be used efficiently, and large quantities of tablet-like particles can be processed. can.

[Brief explanation of the drawing]

The figures show an embodiment of the vacuum-type particle-resistant processing device according to the present invention, in which Fig. 1 is a longitudinal sectional front view thereof, Fig. 2 is an enlarged longitudinal sectional front view of the vicinity of the opening of the ventilation duct, and Fig. 3 is a longitudinal sectional front view of the device. 4 is an enlarged longitudinal sectional front view of the vicinity of the microwave oscillator, and FIG. 4 is a partially cutaway perspective view of the vicinity of the opening of the ventilation duct. Drawing code, 1... Machine base, 11... Bearing part, 2...
... Airtight container, 24 ... Bearing cylinder, 25 ... Rotation drive device, 3 ... Pressure reduction means, 31 ... Ventilation duct, 3
2...Opening, 33...Punching plate, 3
4...Filter cloth, 4...Microwave heating means, 41...
...Partition plate, 42...Microwave oscillator, 5...Spraying means.

Claims (1)

[Claims for Utility Model Registration] Comprising a closed container 2, a pressure reducing means 3, a spraying means 5, and a microwave heating means 4, the closed container 2 includes a bearing tube 24 protruding from the rear wall.
is rotatably supported on the machine base 1 and connected to a rotary drive device 25, and the pressure reducing means 3 inserts a ventilation duct 31 into the bearing sleeve 24, and connects one end of the ventilation duct 31 to the closed container 2. The other end is connected to an external exhaust pump 37.
The spray means 5 includes a spray nozzle 52 in the closed container 2.
The microwave heating means 4 is connected to the ventilation duct 31.
also serves as a waveguide, and the microwave oscillator 42
is provided at the rear end of the ventilation duct 31 via a partition plate 41, and an opening 32 is provided downward at the front end of the ventilation duct 31 in the closed container 2, and at least both sides covering the other parts are provided. Punching plate 33
A vacuum type powder/granular material processing apparatus comprising: and the outer periphery of the opening 32 and the punching plate 33 is surrounded by a filter cloth 34 for a filter.