JPS5936189B2 - Drying equipment for powder and granular materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a rotating body that is driven and rotated along the heating inner surface in a case having a cylindrical heating inner surface, and a rotating body that is formed between the rotating body and the heating inner surface. A frozen powder supply route and a dried material discharge route are connected to the drying space in a state where they are at different positions in the direction of the rotational axis of the rotary body, and by spiral movement as the rotary body rotates. The granular material is configured to be sent from the supply path to the discharge path along the heating inner surface, and the rotating body is provided with an opening for ventilation from the drying space to the internal space of the rotating body, and the rotation The present invention relates to a device that connects a decompression device to the internal body space and dries frozen powder particles uniformly, efficiently, and continuously by depressurizing and heating.

Conventionally, in order to form ventilation openings in the rotating body in the above-mentioned drying apparatus, small holes that do not allow powder to enter were bored in a cylinder with a smooth outer circumferential surface, as shown in Japanese Utility Model Publication No. 1439/1983. However, due to the flow of water vapor generated in the drying space and the stalling and collision of powder and granules, powder and granules tend to become adsorbed to the openings, and once adsorbed, powder and granules It is difficult to separate from the cylindrical body, and the pressure in the drying space increases, making it difficult to carry out stable and good vacuum drying for a long period of time. The purpose of the present invention is to improve the structure of the rotating body to ensure that the ventilation openings formed in the rotating body are not clogged with powder and granules for a long period of time while sufficiently preventing the passage of the powder and granules. The aim is to prevent this from happening.

The characteristic structure of the drying device for powder and granular materials according to the present invention is that the rotary body for moving the powder and granular materials in a spiral manner in the drying space surrounded by the heating inner surface of the case includes a large number of plates.
The plates are arranged in an annular manner with their surfaces facing the direction of rotation, and an opening for ventilation from the drying space to the decompression device is formed between the plates. The reason is that it is inclined with respect to the direction of the radius of rotation so that the rotation angle is at the rear, and its effects are as follows. In other words, when the powder or granules in the heating space move toward the rotating body, the surfaces of the plates facing in the direction of rotation and the direction of the rotation radius collide with the powder at high speed, causing the particles to be thrown away by the plate. The material can be returned to the heating inner surface side and with a large dynamic inertia along the heating inner surface.Also, since the plates are arranged side by side to form a powder splashing surface, even if the opening width between the plates is Even if the width of the plate is made large enough to prevent clogging of the powder, it is difficult to ensure that the plate collides with the powder trying to pass through the vent opening by making the width of the plate appropriately large. As a whole, it is possible to sufficiently prevent powder and granules from passing through the ventilation openings of the rotating body, while also reliably preventing the openings from being clogged with powder and granules, allowing continuous drying over long periods of time. It has become possible to perform the drying process successfully and reliably without deteriorating the vacuum drying function.

Furthermore, because many plates are arranged side by side, the powder and granules are evenly distributed over the entire circumference of the rotating body, and the powder and granules are evenly scattered over the entire heating inner surface. In addition, the powder is always reliably pressed, and the heating drying function under reduced pressure can be improved almost exclusively by conductive heat transfer.
A drying device with extremely excellent performance was obtained.

Next, an example will be shown with reference to FIGS. 1 and 2.

Inside a case 2 having a horizontally oriented cylindrical heating inner surface 1, there are provided outer and inner rotating bodies 5a and 5b which are respectively linked to a horizontally oriented rotating shaft 3 and a rotary cylinder shaft 4 fitted externally thereto.
The frozen powder and granule passages 6 are located at one end of a and 5b, and the dry matter discharge route 7 is connected to the other end of the case 2, respectively, and the frozen powder and granule from the supply route 6 are connected to the space inside the case 2. A stirring and feeding blade 8 for transferring the body to the drying space formed between the heating inner surface 1 and the rotating bodies 5a and 5b is attached to the rotating cylinder shaft 4, and a transmission device is attached to the rotating shaft 3 and the rotating cylinder shaft 4, respectively. 9a
, 9b, the driving device 10 interlocks and connects,
The rotating bodies 5a, 5b and the blades 8 are configured to drive and rotate in the same direction, and the powder and granules are supplied in a thin layer along the heating inner surface 1 by spiral movement accompanying the rotation of the rotating bodies 5a, 5b. The powder is sent from the path 6 to the discharge path 7, and is heated by contact heat transfer with the heating inner surface 1. a first jacket 11 for heating the heating inner surface 1;
The case 2 is equipped with a second jacket 11b for heating the inner surface of the portion housing the blade 8, and lower supply channels 12a and 12 connected to an appropriate device such as a boiler.
Heating fluid at an appropriate temperature is supplied from jackets 11a and 11b from b.
The structure is such that an appropriate amount of fluid is supplied to each fluid, and used fluid is taken out from upper discharge passages 13a and 13b.

The inner and outer rotating bodies 5a, 5b are configured by a second
As shown in the figure, a large number of plates 14 are arranged side by side in an annular manner with their surfaces facing the direction of rotation, gaps 15 are formed between the plates 14, and each of the plates 14 is The outer rotating body 5a is tilted with respect to the rotation radius direction so that the rotation phase of the outer edge side is later than that of the inner edge side, so that when the powder collides with the liquid 14, it is blown away to the heating inner surface 1 side. Even if there is powder or granular material passing through, the structure is such that the powder or granular material passes through the outer rotary member 5a and is returned to the drying space by the action of the inner rotary member 5b.

An agitating and scraping member 16 is attached to the outer rotating body 5a in a state of protruding outward, and the action of the member 16 prevents the adhesion of powder and granules over the entire heating inner surface 1. The structure is such that the retention time of the powder or granular material in the drying space can be set by setting the mounting angle of the member 16. Further, the scraping member 16 is configured to be divided in the axial direction of the outer rotary body 5a, and adjacent divided portions are
The phase is different in the circumferential direction. Moreover, the rotating bodies 5a, 5
An annular weir 19 is provided between the discharge path 7 and the discharge path 7, the position of which can be finely adjusted in the far and near directions with respect to the partition wall 18 adjacent to the rotating bodies 5a and 5b by means of a rotary operation lever 17. The structure is such that the residence time of the powder or granular material can be adjusted.

Rotary air lock valves 20a and 20b are provided in the supply path 6 and the discharge path 7 to completely prevent outside air from flowing into the case 2, and communicate with the inner space of the inner rotating body 5b. The exhaust path 20 is connected to a pressure reducing device 23 via a moisture removal device 22, and the drying space is maintained in a near-vacuum state sufficient for moisture sublimation through a gap 15 between the two rotating bodies 5a and 5b. Furthermore, the frozen powder and granular material is vacuum-heated and dried in the drying space, and the sublimated water vapor and other evaporative gases are discharged. In constructing the case 2, the end wall portion 24 on the side of the discharge path 7 is connected to a partition wall 18 connected to the end wall portion 24.
and the annular weir 19, and the rotary shaft 3 is divided into parts so that the inner rotating body 5b can be inserted into and removed from the case 2 with the end wall portion 24 removed. Furthermore, the exhaust part 26 which forms the exhaust chamber 25 and is provided with the bearing part 27 of the rotary cylinder shaft 4 is configured to be detachable together with the outer rotary body 5a and the stirring and feeding blades 8, so that maintenance and inspection can be carried out. It is designed to be easy to carry out. Examples of target powders include various foods, drinks,
Frozen and pulverized products of cosmetics, pharmaceuticals, or spices are suitable.

In addition, when the rotary body 5 is constructed by arranging the plates 14 that are simply tilted backwards as described above, it is possible to effectively prevent the clogging of the powder or granular material in the gap 15 for exhaust. or net-like perforated plates formed into a cylindrical shape, etc.
Various configurations can be used, and in short, any configuration may be used as long as it has an opening 15 for ventilation from the drying space to the inner space of the rotating body 5 and has a function of imparting rotational force to the granular material. .

Furthermore, by providing two or more rotating bodies 5 as described above, it is possible to reliably prevent the powder from flowing into the inner space of the rotating bodies 5, and to reduce the thickness of the powder layer in the drying space between the rotating bodies. Although it has extremely excellent advantages such as making it easier to achieve uniformity over the entire circumference of the rotating body 5, it is sufficiently practical to provide only one rotating body 5.

When the rotating bodies 5 are arranged in duplicate, the inner one 5b
By setting the angular velocity of the outer part 5a to be the same as or preferably higher than that of the outer part 5a, it is possible to more effectively prevent the powder from flowing into the inner space of the rotating body 5. In addition, as mentioned above, if the axis of the rotating body 5 is oriented horizontally, it becomes easier to equalize the thickness of the powder layer in the drying space, and it becomes easier to control the residence time of the powder in the drying space. Although there is an advantage, it is also possible to make the axis of the rotating body 5 tilted or vertical, and in that case, it is preferable to connect the supply path 6 downward and the discharge path 7 above with respect to the drying space. . In addition, supply route 6
Alternatively, the discharge path 7 may be connected to the drying space at a location facing the rotating body 5. In other words, the paths 6 and 7 may be connected to the drying space at different positions in the direction of the rotational axis of the rotating body 5. It is fine as long as it is connected.

Further, the heat source for the heating inner surface 1 can be variously changed, such as an electric heating type.

[Brief explanation of the drawing]

The drawings illustrate aspects of an embodiment of the drying apparatus for powder and granular materials according to the present invention, and FIG. 1 is a longitudinal sectional view, and FIG. 2 is a sectional view taken along the line 1--... in FIG. 1. 1...Heating inner surface, 2...Case, 5.
...Rotating body, 6... Supply route, 7...
...Discharge route, 14...Plate body, 15...
...Opening (gap), 18...Annular weir, 19...
...Partition wall, 23...Reducing pressure device.

Claims (1)

[Scope of Claims] 1. A rotating body 5 driven and rotated along the heating inner surface 1 is provided in a case 2 having a cylindrical heating inner surface 1, and a rotating body 5 is provided between the drying body 5 and the heating inner surface 1. A frozen powder supply route 6 and a dry matter discharge route 7 are connected to the drying space where
The rotary body 5 is connected at different positions in the rotational axis direction, and the powder and granules are moved from the supply path 6 to the heating inner surface 1 by spiral movement accompanying the rotation of the rotary body 5. The rotating body 5 is provided with an opening 15 for ventilation from the drying space to the inner space of the rotating body 5, and a pressure reducing device 23 is connected to the inner space of the rotating body 5. In this drying device for powder and granular materials, the rotating body 5 is constructed by arranging a large number of plates 14 in a ring shape with their surfaces facing the direction of rotation, and forming the opening between the plates 14. 15, and the plates 14 are tilted with respect to the rotation radius direction so that the rotation phase on the outer edge side is later than on the inner edge side. . 2. The device according to claim 1, characterized in that the rotating bodies 5 are arranged doubly. 3. An annular weir 19 is provided with respect to the partition wall 18 adjacent to the rotary body 5, the position of which can be freely changed in the distance direction, so that the residence time of the powder and granular material in the drying space can be adjusted. An apparatus according to claim 1 or 2.