JP2001170470A - Closed type kneader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of material burning or the like by suppressing temperature rise due to shearing heat generation in a kneading process of a material to be kneaded and to enable one stage kneading while adding a vulcanizing agent by increasing cooling efficiency by a jacket system. SOLUTION: A pair of rotors 3, 3 rotating in mutually different directions are provided in a kneading chamber 2 and a cooling jacket 10 is provided so as to surround the kneading chamber 2. Inside the cooling jacket 10, a cooling water flow passage 15 meandering so as to fold back several times by baffle plates 11, 12 is formed and a water supply port 16 is provided at one end thereof and a drainage port 17 is provided at another end. At least one heat radiating plate 18 is respectively provided between respective baffle plates 11, 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a closed kneader used for kneading materials to be kneaded such as rubber.

[0002]

2. Description of the Related Art As shown schematically in FIG.
, A pair of rotors 3, 3 disposed in the kneading chamber 2, a casing 4 extending to an upper portion of the kneading chamber 2, and disposed in the casing 4 so as to be able to move up and down. Floating weight 5 and the kneading chamber 2
And a material temperature detecting section 6 located at the lower part of the table. The kneading chamber 2 has a shape in which two cylindrical spaces whose axes are parallel to each other are communicated with each other at a part in a circumferential direction thereof, and a rotating shaft arranged concentrically with each of the cylindrical spaces. The rotors 3 and 3 are rotated in different directions by motors (not shown) via 3a and 3a.

That is, in this internal mixer, a material to be kneaded, such as a rubber material, introduced into a casing 4 from an upper inlet (not shown) is pressed into a kneading chamber 2 by lowering a floating weight 5, and the kneading chamber 2 Within rotor 3,3
Is kneaded for a required time by the rotation of, and is discharged from the material discharge section.

In the kneading process, the material to be kneaded generates heat by being continuously subjected to shearing. In particular, since heat is remarkably generated in the kneading of the rubber material, if a vulcanization accelerator is added and kneaded at a time (one-stage kneading), a vulcanization reaction occurs due to a rise in temperature of the rubber material to be kneaded, and the subsequent vulcanization reaction occurs. Molding with a mold becomes impossible.
Therefore, in order to suppress the temperature rise due to such shearing heat generation, the closed kneader is provided with a cooling means. As the cooling means, for example, a drilled side method or a jacket method has conventionally been used. Have been.

[0005] However, the cooling means of the conventional drilled-side method increases the initial cost of the apparatus, and may cause clogging if the condition of the cooling water is poor. In addition, as shown in FIG. 3, a conventional cooling means using a jacket system forms cooling jackets 7 surrounding a kneading chamber 2 in a chamber 1, and a required number of baffle plates are provided in each cooling jacket 7. 7a, 7
The cooling water CW is continuously formed from a water supply port 8 provided at one end of the flow path to a drain port 9 provided at the other end. The flow rate of the cooling water CW is slower than
The cooling rate was slow because the wall between the kneading chamber 2 and the kneading chamber 2 had a considerable thickness in terms of strength calculation.

FIG. 4 shows the transition of the kneading power and the temperature of the material to be kneaded in the kneading process when the cooling means of the conventional jacket system is employed. As is clear from this figure, when kneading is started, the temperature of the material to be kneaded increases due to shear heat generation. Depending on the type of material to be kneaded, the temperature rise is small. For this reason, one-stage kneading, in which a vulcanization accelerator is added from the beginning and kneading is performed at once, is possible, but in most cases the temperature rise is remarkable. First, kneading without adding a vulcanization accelerator to the material to be kneaded (A
Kneading), and then kneading (B-kneading) by adding a vulcanization accelerator to this material, and performing two-stage kneading.

[0007] In the two-stage kneading, after kneading A by a closed kneader, the material to be kneaded is once discharged and cooled for a predetermined time, and then B kneading is again performed by a closed kneader. There is a method in which B kneading is continuously performed by a roll after A kneading by a machine, but in each case, a large number of man-hours are required as compared with one-stage kneading.

Further, since the upper limit of the material temperature to which the vulcanization accelerator can be added is often 100 to 120 ° C., in a conventional jacket type cooling means, for example, the cooling rate per minute is 20 ° C. Even if the temperature is about 0 ° C., if the material temperature rises to 140 to 160 ° C. during the kneading process, a waiting time of 1 to 3 minutes is required for cooling to a temperature at which the vulcanization accelerator can be added. become. Moreover, since the material to be kneaded is in the form of a large block, the internal temperature does not easily drop even after the elapse of the waiting time. Therefore, when the B kneading is started, the material temperature rises in a short time. , There was a risk of causing dough burning.

[0009]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a main technical problem thereof is that a closed kneader having a jacket type cooling means is provided. An object of the present invention is to increase the cooling efficiency, thereby suppressing the temperature rise of the material to be kneaded, preventing the occurrence of scorching of the dough, etc., and enabling one-stage kneading to improve productivity and quality.

[0010]

Means for Solving the Problems As means for effectively solving the above-mentioned technical problems, the present invention relates to a closed kneading machine having a cooling jacket for supplying a cooling medium around a kneading chamber. A required number of heat radiating plates are provided in the cooling jacket, thereby increasing the contact area of the cooling medium with the cooling jacket and improving the cooling efficiency.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic structure of a closed kneader according to the present invention. That is, as shown in FIG. 1A, which is a cross-sectional view cut along a plane perpendicular to the axis of the rotors 3, 3, the closed kneader has an axis center inside a chamber 1 made of steel or the like. A kneading chamber 2 having a shape in which two cylindrical spaces parallel to each other are communicated with each other at a part in the circumferential direction is formed. A pair of rotors 3, 3 are arranged in the kneading chamber 2, and these rotors 3, 3 are illustrated via rotary shafts 3a, 3a inserted concentrically with the cylindrical spaces. The motors are rotated in mutually different directions by motors that are not used.

In a casing 4 extending from the chamber 1 to the upper part of the kneading chamber 2, a floating weight 5 is moved up and down by a hydraulic cylinder device or the like (not shown) at a position shown by a dashed line in FIG.
Is arranged. A material temperature detector 6 is provided at the lower center of the kneading chamber 2, and a pair of cooling jackets 10 are arranged so as to surround the kneading chamber 2 from both sides of the material temperature detector 6 to the upper side of the kneading chamber 2. , 10 are provided.

In each cooling jacket 10, each rotor 3, 3 (rotating) extends across an inner wall 13 between the kneading chamber 2 and the cooling jacket 10 and an outer wall 14 of the cooling jacket 10. Baffle plates 11, 12 extending in the circumferential direction about the axis of the shafts 3a, 3a) are provided alternately in the axial direction. Of these, the baffle plate 11 has an opening 11a for turning back the flow path at the end on the upper end wall 10b side of the jacket 10, and the baffle plate 12 is opposite to the baffle plate 11, Has an opening 12a at the end on the material temperature detecting section 6 side for turning back the flow path.

Inside each cooling jacket 10, baffle plates 11 and 12 are formed with cooling water passages 15 meandering alternately in the circumferential direction. The number of the baffle plates 11 and 12 is determined according to FIG.
In other words, the installation interval is narrower than that of the prior art, so that the cross-sectional area of the cooling water flow path 15 is smaller than in the prior art.

In the lower part of the cooling jacket 10, a water supply port 16 is opened at one end of a cooling water flow path 15 formed by the baffle plates 11 and 12 inside the cooling jacket 10. Is connected to a cooling water supply source (not shown) via a pipe. In addition, a drain port 17 is formed at the upper end of the cooling jacket 10 at the other end of the cooling water flow path 15.

FIG. 1B schematically shows the internal structure of the cooling jacket 10 between the baffle plates 11 and 12.
As shown by the broken lines in FIG. 3C, one or more heat radiating plates 17 are provided. Each of the heat radiating plates 17 extends along the cooling water flow path 15, and is provided integrally on the inner wall 13 between the kneading chamber 2 and the cooling jacket 10, or between the inner wall 13 and the cooling jacket 10. It is provided so as to straddle the outer side wall 14.

The closed kneading machine having the above-described structure is configured to lower the floating weight 5 to the position shown by the dashed line in the figure to thereby mix the kneaded material such as rubber material pressed into the kneading chamber 2 with the rotor 3, Knead by 3 rotations. At this time, cooling water CW from a cooling water supply source (not shown) is supplied into the cooling jackets 10 and 10.
It is continuously supplied through 6,15. The supplied cooling water CW meanders in the cooling jacket 10 repeatedly along the cooling water flow path 15 formed by the baffle plates 11 and 12, as indicated by a number of arrows in the figure. While flowing, it is discharged to the outside from the drain port 17.

In the kneading process by the rotors 3, 3, the heat generated when the material to be kneaded is continuously sheared is
Heat is radiated to the cooling water CW flowing through the cooling water flow path 15 in the cooling jacket 10 via the inner wall 13 between the kneading chamber 2 and the cooling jacket 10, the baffle plates 11 and 12, and the heat radiating plate 17. And according to this embodiment, the baffle 1
By providing the heat radiating plate 17 between the cooling water CW 1 and the cooling water CW, the contact area (heat radiating area) with the cooling water CW is increased, and the installation interval of the baffle plates 11 and 12 is narrowed to reduce the sectional area of the cooling water flow path 15. By making it smaller than before, cooling water CW
And the cooling efficiency is improved as a result.

FIG. 2 shows the transition of the kneading power and the temperature of the material to be kneaded in the kneading process by the internal mixer according to the present invention. As is apparent from FIG. 2, when kneading is started, the temperature of the material to be kneaded rises due to shearing heat accompanying the kneading. However, the temperature rise increases due to the improved cooling efficiency in the cooling jackets 10, 10. 4 is reduced by about 25% compared to the prior art shown in FIG.

In FIG. 2, kneading (A kneading) is first performed without adding a vulcanization accelerator to the material to be kneaded, then kneading is stopped once, and the material to be kneaded is cooled for a predetermined time.
Next, a vulcanization accelerator is added to this material and kneaded (B kneading).
The temperature change in the case of two-stage kneading, such as performing
Due to the cooling action from 0, 10, the temperature is much lower than the maximum temperature of 120 ° C. at which the vulcanization accelerator can be added.

Therefore, in this case, one-stage kneading, in which a vulcanization accelerator is added from the beginning and kneading is performed at a time, becomes possible. One-stage kneading can reduce man-hours by 30% or more compared to two-stage kneading. Further, since the maximum temperature during kneading can be kept lower than before, the time required to cool the inside of the chamber to a temperature at which the next kneading can be started after kneading can be reduced, for example, by 50% or more.

[0022]

According to the internal mixer of the present invention, the temperature rise due to shear heat generation during kneading can be suppressed lower than before, so that the waiting time for cooling the chamber to a temperature at which the next kneading can be started is reduced. Since the cooling efficiency can be shortened, and in particular, the one-stage kneading becomes possible by the improvement of the cooling efficiency, in this case, the man-hour is remarkably reduced and the productivity is improved. Moreover, since the temperature rise is suppressed, the viscosity decrease of the material to be kneaded due to the temperature rise is also suppressed, so that a greater shear force is applied to improve the kneading efficiency, and as a result, the quality of the material can be improved. it can.

In addition, in the two-stage kneading, when the vulcanizing agent system is charged by a roll into the kneaded material after the kneading in A and the kneading is performed in B, the input of the vulcanizing agent system varies by an operator. Whereas there was fear, according to the present invention, 1
By enabling the stage kneading, the vulcanizing agent system can be charged in the internal mixer, so that the vulcanizing agent charging and kneading operations can be automated and the quality can be reduced.

[Brief description of the drawings]

FIG. 1 shows a schematic configuration of a closed kneader according to the present invention, in which (A) is a cross-sectional view cut along a plane orthogonal to the axis of a rotor, and (B) is a direction viewed from the arrow B in (A). (C) is an internal structure diagram of the cooling jacket in the direction of arrow C in (A).

FIG. 2 is an explanatory diagram showing transition of kneading power and temperature of a material to be kneaded in a kneading process by a closed kneader according to the present invention.

FIG. 3 shows a schematic configuration of a conventional closed kneader.
(A) is a cross-sectional view cut along a plane orthogonal to the axis of the rotor, (B) is an internal structural view of the cooling jacket in the direction of arrow B in (A), and (C) is the direction of arrow C in (A). It is an internal structure figure of the cooling jacket of FIG.

FIG. 4 is an explanatory diagram showing transition of kneading power and temperature of a material to be kneaded in a kneading process by a conventional closed kneader.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chamber 2 Kneading chamber 3 Rotor 3a Rotating shaft 4 Casing 5 Floating weight 6 Material temperature detecting part 10 Cooling jacket 10a, 10b End wall 11, 12 Baffle plate 11a, 12a Opening 13 Inner side wall 14 Outer side wall 15 Cooling water flow path 16 Water supply Mouth 17 Drainage port 18 Heat sink CW Cooling water

[Procedure amendment]

[Submission date] February 15, 2000 (2000.2.1
5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction contents]

FIG. 1B schematically shows the internal structure of the cooling jacket 10 between the baffle plates 11 and 12.
As indicated by the broken line (C), the release or one each
A hot plate 18 is provided. Each of the heat radiating plates 18 extends along the cooling water flow path 15, and is provided integrally on the inner wall 13 between the kneading chamber 2 and the cooling jacket 10, for example, or provided between the inner wall 13 and the cooling jacket 10. It is provided so as to straddle the outer side wall 14.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

In the kneading process by the rotors 3, 3, the heat generated when the material to be kneaded is continuously sheared is
Heat is radiated to the cooling water CW flowing through the cooling water flow path 15 in the cooling jacket 10 via the inner wall 13 between the kneading chamber 2 and the cooling jacket 10, the baffle plates 11 and 12, and the heat radiating plate 18 . And according to this embodiment, the baffle 1
By providing the heat radiating plate 18 between the cooling water CW and the cooling water CW, the contact area (heat radiating area) with the cooling water CW is increased. By making it smaller than before, cooling water CW
And the cooling efficiency is improved as a result.

[Procedure amendment 4]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

Claims (1)

[Claims] A cooling medium (C) is provided around a kneading chamber (2).
W), wherein a required number of radiating plates (1) are provided in the cooling jacket (10).
A closed kneader, wherein 2) is provided.