JPS6161028B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION When the present invention continuously dries powder and granular materials such as synthetic resin chips and tablets using a tray dryer,
The present invention provides a tray type dryer that is devised to minimize unevenness in product quality.

Various types of dryers such as fluidized bed dryers, rotary dryers, and stirring dryers are used as continuous dryers for powder and granular materials such as synthetic resin chips and tablets. However, the shape of the powder may be damaged during drying, and the dryer described above is not sufficient to maintain product quality within a certain range.

Particularly among synthetic resin chips, in the case of synthetic resin chips used for fibers such as polyamide and polyester, if they are not dried to maintain a certain moisture level, problems may occur during the spinning or drawing process.

For this reason, when polyamide or polyester chips are continuously dried, the dryer is strongly required to have piston flow properties. That is, the chips placed in the dryer must be discharged after the required drying time has been set. Of course, it is impossible for a dead space to exist.
Furthermore, even if the piston flow properties are extremely good, if the chips break or rub during drying, and the chips break up and become smaller pieces or powder, it can still cause trouble in the spinning process. .

As described above, a dryer for synthetic resin chips for textiles is strongly required not only to have good drying efficiency but also to have extremely good piston flow properties without damaging the shape.

Under these circumstances, tray dryers have recently been used for drying synthetic resin chips, tablets, and even food-related products. Figures 1 to 3 are schematic explanatory diagrams of such a dryer, in which annular plates 2, 2' each provided with a jacket 3 for a heat medium are arranged in multiple stages inside a vertical columnar container body 1. A blade (rake) is provided and rotates in contact with the plates 2, 2'.
A rotary shaft 4 having a plurality of arms 6 attached in the radial direction is disposed perpendicularly to the center of the main body 1. The relationship between the plates 2 and the blades 5 is such that in odd-numbered stages from the top, as shown in Figure 2, a weir plate 2a is provided at the inner peripheral end of the plate 2, and the blades 5 move the powder on the plate 2 to the outer peripheral side. It is installed obliquely to the radial direction so that the In the even-numbered stages, the outer and inner diameters of the plates 2' are larger than those in the odd-numbered stages, as shown in Figure 3, and the blades 5' are opposite to those in the odd-numbered stages so as to move the powder to the inner circumference (inner diameter) side. The weir plate 2b is attached to the outer peripheral edge.
is provided. In such a conventional tray type dryer, the inlet and outlet nozzles 7,
When chips are quantitatively supplied from the input port 9 onto the plate 2 heated to a predetermined temperature via the rotary shaft 4 rotated by the motor 10, the blades 5
rotates around the rotating shaft 4 while in contact with the plate 2, whereby the chips are dispersed in a thin layer or wave shape, move spirally to the outer circumferential side, and fall onto the lower plate 2'. On the even-numbered plates 2', the chips move toward the inner periphery and fall from the inner edge to the lower tier, and in the same way, the chips fall sequentially to the lower tier and are dried for a predetermined time on the bottom surface 11 of the main body 1. However, such conventional devices have the following problems.

That is, as described above, the powder or granular material to be treated moves on the plates 2, 2' to the inner circumferential side or the outer circumferential side and falls from the plates 2, 2' to the plates 2, 2'. In the case of powder or synthetic resin chips, they have a high elasticity, so they tend to scatter in all directions and cause short passes.
2', some particles collide with each other and jump over the plates 2a, 2b and go straight to the lower surface 11 of the main body. As described above, shot passes frequently occur due to scattering due to collisions of powder particles when they fall, which destroys piston flow properties, resulting in uneven drying, which causes trouble in subsequent processes.

In view of the current situation, the inventor has conducted extensive research and found that
To devise a tray dryer that can stably obtain excellent products with consistent quality without causing unevenness in product quality when continuously drying powdered materials such as synthetic resin chips and tablets. I've reached it.

That is, in the present invention, plates having heat medium jackets are arranged in multiple stages in a vertical columnar container having a circular or polygonal cross section, and a plurality of blades are provided on each plate in contact with the plates in the radial direction. A shelf with an arm attached to a rotating shaft placed perpendicular to the center of the container, so that the powder and granules supplied from the upper input port are transferred to the inner or outer circumference of the plate and sequentially fall onto the lower plate. In a tiered dryer, a chute that rotates together with a rotating shaft is arranged between the plates and near the inner or outer edge of the plate at a position corresponding to the innermost or outermost blade, and , a tray type dryer characterized in that the blades are provided at a position immediately after the chute outlet, and a weir plate is provided on the peripheral surface side of the plate corresponding to the chute outlet position.

Hereinafter, the present invention will be explained based on the drawings. Fourth
The figure is a schematic cross-sectional view showing an embodiment of the present invention, and FIGS. 5 and 6 are plan views of plate portions of odd-numbered stages and even-numbered stages. In the figure, 20 and 20' are an arm 21 fixed to the rotating shaft 4 between each plate 2 and 2',
The chute 20 is located above the plate 2' and is attached to its tip via 21'.
The inlet 20a opens at a position corresponding to the outermost blade 5 near the outer peripheral edge of the plate 2 (the position where the powder falls from the outer peripheral edge of the plate 2 by the blade 5), and the outlet 20b opens at a position corresponding to the outermost blade 5 near the outer peripheral edge of the plate 2. It opens at a position near the outer peripheral end of the blade 2' and corresponding to the outermost blade 5' (a position where the fallen powder is fed by the outermost blade 5').

On the contrary, the chute 20' located above the plate 2 is disposed on the inner peripheral end side of the plates 2, 2' in the same arrangement as the chute 20 described above. Furthermore, main body 1
The input port 22 provided at the top of the inlet 22 is opened so that its lower end outlet 23 is as close to the plate 2 as possible within a range that does not interfere with the rotation of the arm 6. The other configurations are similar to those shown in FIGS. 1 to 3, and are indicated by the same symbols as in FIGS. 1 to 3.

Next, in a device having such a configuration, for example, synthetic resin chips supplied from the input port 22 fall onto the inner circumferential edge of the uppermost plate 2, and are turned into a thin layer or wave shape by the rotating blades 5. It is dried during this time while gradually moving toward the outer circumferential side. The chips that have moved to the outer peripheral end are held in a predetermined position together with the blades 5, are received by the rotating chute 20, and fall onto the outer peripheral end of the next plate 2'. Due to the rotation of the arm 6, the chips that have fallen to the second stage move in the same way as the first stage, but in the opposite direction (inner circumferential direction) (approximately the length of the blade in the radial direction per rotation). At a predetermined rotation of
0' to the lower stage, that is, the third stage plate 2.
fall on top. In this case, the chip is shoot 2
Since it falls onto the next plate 2, 2' through the chute 20, 20', it is regulated by the chute 20, 20', and it does not scatter in all directions and almost falls onto the chute 20, 2'.
Since it is located below 0', short passes etc. do not occur.

Next, the above-described operation is repeated so that the chips are transferred to the bottom surface 11 of the main body at the lowest stage, and the chips that have been dried for a predetermined period of time are taken out from the discharge port 12. Here, the relationship between the chute and the upper and lower stages of the blades is as shown in FIGS. Installed immediately after the exit,
From the viewpoint of efficient drying, it is preferable to arrange the apparatus so that the chips falling from the upper stage through the chute are immediately moved. The chute 20, 20' is preferably attached to the arm 21, 21' so that it can be changed vertically or horizontally (front and back) depending on the powder or granular material to be processed, and the shape of the chute 20, 20' may be curved or curved to soften the impact when dropped. Rotating shaft 4 (blade 5,
The rotational speed of the rotation speed 5' is appropriately determined depending on the powder and granular material to be treated, the drying time, etc., but from the viewpoint of piston flow properties, the lower the speed, the better, and it is usually 3 rpm or less. The depth of the granular material is determined by considering drying efficiency, equipment capacity, etc., but in the case of chips, it is usually 5 to 30 mm.
and the outlet 20b, 20'b of the chute
It is preferable that the distance between the chips and the plates 2, 2' be approximately 10 to 30 mm from the upper layer of chips on the plates 2, 2'.

In this embodiment, drying is carried out by heating the plates 2, 2', but it goes without saying that hot air supply or vacuum suction may be carried out at the same time.

Further, a chute may also be provided between the final stage plate and the lower surface of the main body. As explained above, according to the present invention, a chute that rotates with the blades is installed between the plates, and the powder and granules are dropped onto the next plate through this chute.
The powder and granules that fall between the plates can be supplied to the outer or inner edges of the plates without scattering, and there is no shot pass of the powder, making it possible to stably obtain products of extremely high quality and consistency. becomes.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional schematic diagram showing a conventional embodiment;
3 and 3 are schematic plan views of odd-numbered stages and corner-numbered stages of the plate section shown in FIG. 1, FIG. 4 is a schematic cross-sectional view showing an embodiment of the present invention, and FIGS. FIG. 3 is a schematic plan view of odd-numbered stages and even-numbered stages of the plate section shown in the figure. 1... Container body, 2, 2'... Plate, 4...
...rotating shaft, 5, 5'... blade, 20, 20'... chute, 21, 21'... arm.

Claims (1)

[Scope of Claims] 1. Plates having heat medium jackets are arranged in multiple stages in a vertical columnar container with a circular or polygonal cross section, and each plate has a plurality of blades in contact with the plates in the radial direction. The provided arm is attached to a rotating shaft placed perpendicularly to the center of the container, so that the powder and granules supplied from the upper input port are transferred to the inner or outer periphery of the plate and sequentially fall onto the lower plate. In the tray type dryer, a chute that rotates together with the rotating shaft is arranged between the plates and near the inner or outer edge of the plate at a position corresponding to the innermost or outermost blade. In addition, a tray type dryer characterized in that the blades are provided at a position immediately after the chute exit, and a weir plate is provided on the peripheral surface side of the plate corresponding to the chute exit position. 2. The tray dryer according to claim 1, wherein the chute is disposed at a position corresponding to the innermost or outermost blade provided on the arm.