JPS629055Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a raw material injection plate for a granulator.

This is one type of granulation device that utilizes the cooling effect of counterflow of gas. This type of granulation equipment has a vertical tower, and from above the tower, synthetic resin, wax, raw materials for chemicals, etc. are injected in a molten state through various injection nozzles and dropped down the tower. A gas such as air or nitrogen is sent from below as a cooling medium, brought into contact with the injected granular material, cooled, and taken out as particles of a predetermined size.

By the way, the size and shape of the particles are related to whether the injection temperature of the raw material is appropriate.
In other words, it depends on whether the viscosity of the raw material is appropriate, and it also depends on whether the functions of the injection device can be properly performed, such as the injection speed of the raw material and the normal opening of the injection hole.

Figure 1 shows a typical injection device of this type that has been used in the past. In the figure, 1 is the main body of the injection device;
A raw material inlet 2 is provided at its upper end, through which molten raw material is fed through a pipe (not shown), and the injection device main body 1 is heated by a jacket 3 with steam or the like. Only a small portion of this heat is transmitted to the injection plate 4 through the packing 10. Spray plate 4
Injection holes 5 having a suitable shape, number, arrangement, pitch, etc. are opened in the hole.

In an injection device having such a structure, the injection plate 4 is
On the bottom surface, when the molten raw material is flushed in the case of batch operation of the raw material pot, due to contact with the air rising up the tower, compressed air, etc., is jetted out from the injection device main body 1 through the injection hole 5. Therefore, the injection plate 4 was cooled. It should be noted that the amount of heat transferred from the jacket 3 to the injection plate 4 through the packing 10 cannot be expected much even if a metal packing is used, and as the diameter of the injection plate 4 increases, this tendency increases. Therefore, the molten raw material solidifies and adheres to the lower surface of the injection plate 4, and during operation, these re-melt and fall as large droplets, which adhere to and solidify to the hopper at the bottom of the tower, or particles much larger than the product particles are mixed in. I did it. Further, there was a drawback that the molten raw material solidified in the injection holes 5 of the injection plate 4, and the shape of the injection holes 5 could no longer be maintained, resulting in uneven particle diameters.

These phenomena are related to the melting point of the substance used, and are particularly noticeable in the case of substances with high melting points.

Furthermore, it takes a long time for the spray plate 4 to warm up at startup, which is particularly inconvenient in winter.

Therefore, as a solution to the above-mentioned drawbacks, a structure has been proposed in which the seeded heater 9 is mounted parallel to the lower surface of the injection plate 4 and slightly apart from the injection plate 4, as shown in FIG. Even if it is possible to prevent the spray plate 4 from cooling down, since the sheathed heater 9 is located on the bottom side of the spray plate 4, the melt may drip and adhere to the spray plate 4, and since there is no temperature control device for the seeded heater 9, the temperature of the spray plate 4 increases. There were drawbacks such as overheating and scorching of the molten liquid.

The present invention has been made to eliminate such drawbacks, and by embedding the seeded heater in the injection plate so that the heat of the seeded heater is directly conducted to the injection plate, the temperature of the injection plate can be automatically adjusted. It is an object of the present invention to provide a raw material injection plate for a granulation device that maintains the temperature of the molten raw material liquid substantially equal to the optimum temperature for injection granulation.

The details of the raw material injection plate of the granulator according to the present invention will be explained below based on the embodiment shown in the drawings. Fig. 3 shows one embodiment, and the same parts as in Fig. 1 are designated by the same reference numerals. There is. In this embodiment, a seeded heater insertion hole 6 is bored inside the injection plate 4 parallel to the upper and lower surfaces and through the vicinity of the injection hole 5 as shown in FIG. 5, and a seeded heater 9 is inserted into this hole 6. At the same time, a temperature detection end is attached to an appropriate location on the spray plate 4 to provide an automatic temperature control device.

The automatic temperature control device includes, as shown in FIG. 6, a temperature detection end 11 attached to an appropriate location on the injection plate 4, a temperature controller 12 to which the temperature detection end 11 is connected, and a power supply circuit 13 for the sheathed heater 9. Temperature controller 1
a switch 14 that connects or disconnects the power supply circuit 13 depending on the presence or absence of a temperature difference between the molten raw material liquid temperature optimal for injection granulation, which is set in advance in step 2, and the temperature of the injection plate 4 detected by the temperature detection end 11; It consists of:

FIG. 4 shows another embodiment, in which the injection plate 4
As the size increases, it becomes difficult to drill the seeded heater insertion holes 6, which are drilled holes as shown in Fig. 3, long and parallel. 4, and the groove holding lid 8 is attached to the bottom surface of the injection plate 4 as a single piece or divided into pieces, and has a removable structure to improve the workability of drilling holes.The other configuration is the same as that of the above embodiment. is the same as

Since the raw material injection plate of the granulator according to the present invention is constructed as described above, the heat of the seeded heater 9 embedded in the injection plate 4 is directly conducted to the injection plate 4. Due to this direct heat conduction, the temperature of the injection plate 4 can be quickly followed and adjusted by adjusting the sheathed heater 9. In particular, a seeded heater 9 is provided near the injection hole 5 to improve temperature controllability in the injection hole 5 portion. The actual temperature control will be described below based on FIG. First, the temperature of the injection plate 4 is constantly detected by the temperature detection end 11, and the detected temperature is compared with the optimal molten raw material liquid temperature for injection granulation, which has been set in advance by the temperature controller 12, and the temperature difference is determined. When the switch 14 is turned on, the power circuit 13 of the seeded heater 9 is connected, and the seeded heater 9
generates a fever. As a result, the injection plate 4 is gradually heated, and when its temperature eventually reaches the optimal molten raw material liquid temperature for injection granulation, the temperature difference with the temperature set in the temperature controller 12 disappears, and the switch 14 is turned OFF.
As a result, the power supply circuit 13 of the seeded heater 9 is disconnected, and the seeded heater 9 does not heat the injection plate 4 above the temperature of the molten raw material liquid that is optimal for injection granulation. Then, when the temperature of the injection plate 4 decreases, a temperature difference occurs between the temperature set in the temperature controller 12, the switch 14 is turned on, the power supply circuit 13 of the seeded heater 9 is connected, the seeded heater 9 generates heat, and the temperature changes again. The spray plate 4 is heated.

In this way, the temperature of the injection plate 4 is automatically maintained substantially equal to the optimum temperature of the molten raw material liquid for injection granulation at all times.

As detailed above, the raw material injection plate of the present invention has a seeded heater embedded in the injection plate to directly heat the injection plate, making it possible to quickly adjust the temperature of the injection plate. The molten raw material will not cool and solidify and stick to the surface. In addition, since the seeded heater is buried near the injection hole, the molten raw material does not solidify inside the injection hole.
The shape of the injection hole is maintained and the product particle size becomes constant.

Furthermore, since the vicinity of the injection hole is directly heated, the time required for warming up the injection plate can be greatly shortened, providing excellent effects.

[Brief explanation of the drawing]

1 and 2 are longitudinal sectional views of a conventional raw material injection plate, respectively, FIGS. 3 and 4 are longitudinal sectional views showing an embodiment of a raw material injection plate according to the present invention, and FIG. 5 is a longitudinal sectional view of a conventional raw material injection plate, respectively. FIG. 4 is a bottom view of the raw material injection plate, and FIG. 6 is a system diagram of the automatic temperature control device equipped on the raw material injection plate to be considered herein. 1... Injection device main body, 2... Raw material inlet, 3...
... Jacket, 4 ... Spray plate, 5 ... Spray hole, 6
... Seeded heater insertion hole, 7 ... Seeded heater insertion groove, 8 ... Groove presser lid, 9 ... Seeded heater, 10 ... Packing, 11 ... Temperature detection end, 12 ... Temperature controller, 13 ... Seeded heater Power supply circuit, 14... switch.

Claims (1)

[Scope of utility model registration request] In a raw material injection plate of a granulation device that has a vertical tower, has an injection device for molten raw material at the top of the tower, and guides a cooling medium in a countercurrent or parallel flow to the tower, near the injection hole of the injection plate. It consists of a heater buried in the heater, a temperature detection end attached to the injection plate in which the heater is buried, and a control device that controls the heater based on a signal from the temperature detection end, and the temperature control device controls the temperature detection end of the heater. 1. A raw material injection plate for a granulator, characterized in that the temperature of the injection plate is directly controlled by controlling a heater.