JPH0780177B2 - Method and apparatus for cooling molten pellets - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for cooling molten pellets, and more particularly, to a molten pellet water stream containing molten pellets after hot-cutting so that the flow velocity of the molten pellet water stream can be reduced by a resistance portion to shorten the length of the cooling water passage. For new improvements to do.

[0002]

2. Description of the Related Art As a cooling device for molten pellets of this type which has been conventionally used, the structure shown in FIGS. 5 and 6 has been generally adopted. That is, what is denoted by reference numeral 1 in FIGS. 5 and 6 is a molten pellet water flow 2 composed of hot-cut molten pellets supplied from a hot cutter (not shown) for cutting molten resin and cooling water. This is a duct-shaped cooling water channel through which
Are arranged at a predetermined height position via a plurality of legs 3.

A water removal treatment section 4 is provided at a downstream position of the cooling water passage 1 so as to drain the cooling water of the molten pellet water stream 2 in a direction indicated by an arrow A. The molten pellets 2a sent out from the rearmost portion 1a of the cooling water passage 1 are dried in the drying unit 5 to obtain dried molten pellets from which water has been removed.

[0004]

Since the conventional molten pellet cooling device is constructed as described above, the following problems have been encountered. That is, the molten pellets in the molten pellet water flow, in which the cooling water after hot cutting and the molten pellets are mixed, are cooled while flowing through the cooling water channel, and after being separated from the water, sent to the drying section in a state containing some water. However, to sufficiently lower the temperature of the molten pellets,
Since it is necessary to lengthen the residence time in the cooling water channel, the cooling water channel had to be long enough to sufficiently lower the temperature of the molten pellets. That is, in the case of a resin having a large heat transfer coefficient in which molten pellets are easily cooled, this residence time may be short, and the length of the cooling water channel can be shortened, but in the case of a resin such as polypropylene having a small heat transfer coefficient, This residence time had to be long, and the cooling water channel was extremely long. Further, if the temperature of the molten pellets is not sufficiently lowered and sent to the drying section, the pellets are often fused together to form an agglomerate, which deteriorates the quality of the molten pellets.

The present invention has been made to solve the above-mentioned problems, and in particular, the flow velocity of the molten pellet water flow after hot cutting is reduced by the resistance portion so that the length of the cooling water passage can be shortened. An object of the present invention is to provide a method and an apparatus for cooling molten pellets.

[0006]

A method for cooling molten pellets according to the present invention is a method for cooling molten pellets, in which a molten pellet water stream containing molten pellets is caused to flow from a hot cutter to a cooling water channel having a water removal treatment section. By providing a resistance portion in the cooling water passage and making the first flow passage width of at least the portion of the cooling water passage where the resistance portion is located larger than the second flow passage width where the water removal processing portion is located, the melting This is a method of reducing the flow velocity of the pellet water flow.

More specifically, it is a method in which cooling water is supplied to the molten pellets passing through the cooling water passage.

Further, the molten pellet cooling device according to the present invention is a molten pellet cooling device in which a molten pellet water flow containing molten pellets is caused to flow from a hot cutter to a cooling water passage having a water removal treatment section. A resistance portion is provided, and at least a portion of the cooling water passage where the resistance portion is located has a first passage width larger than a second passage width where the water removal treatment portion is located.

More specifically, the resistance portion is composed of a plate member and is operably held in the cooling water passage.

More specifically, the cooling water passage is provided with a cooling water sprinkling section for supplying cooling water to the molten pellets. It is a composition.

[0011]

In the method and apparatus for cooling molten pellets according to the present invention, the first flow path is provided at the inlet of the cooling water passage with a resistance part for closing a part of the flow path and at least the part where the resistance part is located. Since the widened portion whose width is set to be larger than the second flow path width in which the water removal processing portion is located, the molten pellet water flow composed of the molten pellets after the hot cutting and the cooling water hits the resistance portion. Since it spreads in the widened portion of the flow path, the flow velocity of this water flow drops at once, and the residence time of this molten pellet in the cooling water path becomes about 2 to 3 times that of the conventional case, and the cooling effect can be improved at once. Moreover, since the cooling water is supplied to the molten pellets from the cooling water sprinkling section above, the cooling effect can be further enhanced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the method and apparatus for cooling molten pellets according to the present invention will be described in detail below with reference to the drawings. It should be noted that the same or equivalent parts as those of the conventional example will be described by attaching the same reference numerals. 1 to 4 are for showing a molten pellet cooling device according to the present invention. FIG. 1 is a side view of the configuration, FIG. 2 is an enlarged configuration cross-sectional view showing the main part of FIG. 1, and FIG. FIG. 4 is an enlarged plan view showing the main part of FIG. 4, and FIG. 4 is a partially cutaway plan view of FIG.

In FIG. 1 to FIG. 4, the reference numeral 1 indicates a molten pellet water flow consisting of molten pellets after hot cutting supplied from a hot cutter (not shown) for cutting molten resin and cooling water. 2 is a duct-shaped cooling water passage, and this cooling water passage 1 is arranged at a predetermined height position via a plurality of legs 3.

A dewatering unit 4 is provided at a downstream position of the cooling water passage 1 so that the cooling water of the molten pellet water stream 2 is discharged in the direction indicated by an arrow A. The molten pellets 2a sent out from the rearmost portion 1a of the cooling water passage 1 are dried in the drying unit 5 to obtain dried molten pellets from which water has been removed.

At the inlet side 1b of the bottom portion 1c of the cooling water passage 1, a resistance portion 10 having a plate structure as shown in FIG. 3 is provided with a plate surface 1 in a direction orthogonal to the direction of the molten pellet water flow 2.
It is arranged to have 0a. This resistance part 10
As shown in FIGS. 2 and 3, the bent rod 12 is engaged with the support rod 11 so that the bent rod 12 can be slightly moved in the directions of the arrows B and C. The flow can be divided as evenly as possible on the left and right to reduce the flow velocity and the degree of resistance can be finely adjusted. The first flow path width D ₁ of the cooling water channel 1 of the portion where the resistor portion 10 is disposed, as shown in Figure 4, the dewatering unit 4 located downstream of the cooling water channel 1 is positioned Second part
A widened portion 50 having a larger width than the flow channel width D ₂ is formed, and the widened portion 50 can sufficiently reduce the flow velocity of the molten pellet water flow 2 flowing on both sides of the resistance portion 10 and its downstream portion. Is configured.

Inside the top plate portion 1d of the cooling water passage 1, a plurality of cooling water sprinkling portions 13 are arranged on the downstream side of the resistance portion 10, and a molten pellet water flow passing through the resistance portion 10 is provided. 2, cooling water 13a is sprinkled from above to enhance the cooling effect. This is because the resin pellets often have a specific gravity of 1 or less, and when such a resin pellet floats in the water stream, the cooling efficiency is deteriorated. It is a structure for helping cooling.

Next, the case where the molten pellets are actually cooled in the above-mentioned structure will be described. First, a molten pellet water stream 2 containing hot-cut molten pellets 2a
Flow into the inlet side 1b of the cooling water passage 1 and the first flow passage width D
_{When 1} hits the resistance portion 10 located in the widened portion and spreads to the widened portion of the flow path, the flow velocity of the water stream 2 is significantly reduced. Since the water flow 2 reaches the downstream side of the cooling water passage 1 via the side portion of the resistance portion 10, the residence time on the cooling water passage 1 is 2 to 3 times that of the conventional one, and at the same time, each cooling water sprinkling portion 1
Since the cooling water 13a from 3 is added to the water stream 2, the temperature of the molten pellets 2a in the water stream 2 rapidly decreases.

Therefore, the molten pellet water flow 2 in which the temperature is further lowered by the sprinkling of the cooling water 13a
The cooling water is removed in the water removal processing unit 4, and is sent to the drying unit 5 as the molten pellets 2a containing water to be completely dried.

In the above-described embodiment, the case where the resistance portion 10 is a plate body has been described, but the shape of the plate body is not limited, and other structures such as a porous member and a sponge body may be used. it can.

[0020]

Since the molten pellet cooling method and apparatus according to the present invention are configured as described above, the following effects can be obtained. That is, since the resistance portion is provided on the inlet side of the cooling water passage and the widening portion of the flow passage width is provided in the cooling water passage, the flow velocity of the molten pellet water flow is significantly reduced by this resistance portion, and the molten pellets are cooled by The residence time of staying on the road is 2-3 times that of the conventional method, and it is possible to lower the temperature by about 7.5 ° C., and it is possible to obtain a cooling effect with a much higher efficiency than the conventional method.

[Brief description of drawings]

FIG. 1 is a side view showing a molten pellet cooling device according to the present invention.

FIG. 2 is an enlarged configuration cross-sectional view showing a main part of FIG.

FIG. 3 is an enlarged plan view showing a main part of FIG.

FIG. 4 is a partially cutaway plan view of FIG. 1.

FIG. 5 is a side view showing the configuration of a conventional molten pellet cooling device.

FIG. 6 is a plan view of FIG.

[Explanation of symbols]

1 Cooling Water Channel 2 Melted Pellet Water Flow 2a Melted Pellet 10 Resistance Part 13 Cooling Water Sprinkling Part 13a Cooling Water D ₁ First Channel Width D ₂ Second Channel Width 50 Widened Section

Claims (5)

[Claims] 1. A method for cooling molten pellets, wherein a molten pellet water stream (2) containing molten pellets (2a) is caused to flow from a hot cutter to a cooling water channel (1) having a water removal treatment section (4). While providing the resistance part (10) in the water channel (1),
Wherein the cooling water passage (1) of at least the second channel width, wherein the water removal processing unit first flow path width (D ₁₎ of the portion in which the resistance unit (10) is located (4) is positioned (D ₂₎ The method for cooling molten pellets is characterized in that the flow velocity of the molten pellet water flow is reduced by increasing the above. 2. The method for cooling a molten pellet according to claim 1, wherein cooling water (13a) is supplied to the molten pellet (2a) passing through the cooling water passage (1). 3. A molten pellet cooling device in which a molten pellet water stream (2) containing molten pellets (2a) is caused to flow from a hot cutter to a cooling water channel (1) having a water removal treatment section (4). While providing the resistance part (10) in the water channel (1),
Wherein the cooling water passage (1) of at least the second channel width, wherein the water removal processing unit first flow path width (D ₁₎ of the portion in which the resistance unit (10) is located (4) is positioned (D ₂₎ The molten pellet cooling device is characterized in that it is also large. 4. The apparatus for cooling a molten pellet according to claim 3, wherein the resistance portion (10) is composed of a plate and is operably held in the cooling water passage (1). 5. The cooling water sprinkler (1) for supplying cooling water (13a) to the molten pellets (2a) in the cooling water passage (1).
The molten pellet cooling device according to claim 3 or 4, further comprising: 3).