JP7210232B2 - Twin-screw mixer and stirring blade cleaning method - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Law (1) Sales to Nisshin Concrete Kogyo Co., Ltd., May 25, 2018 (2) Publication of pamphlet for twin-screw mixer, October 3, 2018 (3) Publication of photo collection of twin shaft mixer, August 30, 2018

TECHNICAL FIELD The present invention relates to a twin-screw mixer that mixes a mixture with a pair of substantially parallel stirring blades, and a stirring blade cleaning method for cleaning the stirring blades.

In order to homogeneously mix a viscous material (viscous material) such as ready-mixed concrete in a short period of time, it is necessary to mix the material (mixed material) while largely circulating in the mixing tank. When mixing ready-mixed concrete, generally, raw materials consisting of gravel (coarse aggregate), sand (fine aggregate), cement (hardening agent) and water are mixed. Raw materials (fine particles) with a small particle size, such as sand and cement particles, tend to form aggregates. If these fine particles remain as agglomerates, the quality of the ready-mixed concrete obtained deteriorates. It is also required to disperse the agglomerates apart.

Focusing on this fact, the present applicant has proposed a pair of stirring blades 2a and 2b (in the document, " A twin-screw mixer equipped with stirring tools 2a and 2b"), wherein each of the stirring blades 2a and 2b has a kneading blade 3 that forms a spiral surface and a spiral surface that is opposite to the kneading blade 3. We have developed a device configured with a switching blade 4 that does. In this twin-screw mixer, the switching blade 4 constituting one stirring blade 2a is arranged so as to be adjacent to the kneading blade 3 constituting the other stirring blade 2b, and the switching blade 4 constituting the other stirring blade 2b. are arranged so as to be adjacent to the kneading blades 3 constituting one of the stirring blades 2a. As a result, the mixture put into the mixing tank 1 (described as "stirring tank 1" in the same document) is largely circulated (see the arrow indicated by the symbol "Z" in FIG. 1 of the same document). is possible. In addition, the mixed material is sheared by entering the gap between the outer end surface of the kneading blade 3 and the inner bottom surface of the mixing tank 1 and the gap between the outer end surface of the turning blade 4 and the inner bottom surface of the mixing tank 1. It is also possible to improve the kneading effect of the mixture.

JP 2006-346510 A

As described above, the twin-screw mixer that mixes the material to be mixed in the mixing tank with a pair of stirring blades can efficiently mix the viscous material. However, in this type of twin-screw mixer, if the material to be mixed is left on the stirring blades for a long time, the material to be mixed will harden, and the material to be mixed will be mixed in the twin-screw mixer. Even if the stirring blades are rotated at that time, the material to be mixed that is being mixed at that time may get caught by the material to be mixed which has hardened before that time and may not circulate as described above, and the desired mixing effect may not be obtained. there were. Depending on how the material to be mixed is cured, it may become impossible to rotate the stirring blades. In this case, if the stirring blades are forced to rotate, the twin-screw mixer may break down. Therefore, after using the twin-screw mixer, it is necessary to thoroughly wash the stirring blades (kneading blades and turning blades).

As a method for cleaning the stirring blades in the twin-screw mixer, for example, the stirring blades are rotated forward (rotating in the direction to circulate the material to be mixed as described above) while washing water is stored in the mixing tank. , a method of washing the stirring blades and the like with water. However, since viscous materials such as ready-mixed concrete tend to stick to stirring blades and the like, it was not possible to sufficiently wash off the mixture adhering to the stirring blades and the like just by performing the above water washing. In particular, as described above, in the cleaning mode in which the stirring blades are rotated forward, the mixture adhering to the front surface of the stirring blade (the surface on the side that pushes the mixture that is circulated during mixing in the transfer direction; the same applies hereinafter) Although it was possible to wash off to some extent, it was difficult to wash off the mixture adhering to the back surface of the stirring blade (the surface opposite to the front surface described above; the same applies hereinafter).

For this reason, in the conventional twin-screw mixer, after cleaning the stirring blades by rotating the stirring blades in the forward direction with cleaning water stored in the mixing tank, the cleaning water is sprayed at high pressure using a cleaning gun or the like. By performing secondary cleaning in which it is sprayed onto the surface, the mixed material that could not be completely removed by the primary cleaning is washed off. However, manual cleaning work using a cleaning gun requires time and effort (usually, about 30 to 60 minutes per twin-screw mixer). In this regard, among conventional twin-screw mixers, there are also models in which a cleaning gun attached to a cover of the twin-screw mixer (not shown) is mechanically and automatically operated. However, in this case, it is necessary to incorporate a mechanism for controlling the cleaning gun into the twin-screw mixer, which poses the problem of making the twin-screw mixer large and expensive.

The present invention has been made to solve the above problems, and is a biaxial mixer that can wash off not only the mixed material attached to the front surface of the stirring blade but also the mixed material attached to the back surface of the stirring blade. The purpose is to provide a machine with as simple a structure as possible. Another object of the present invention is to provide a method for cleaning the stirring blades in this twin-screw mixer.

The above issues are
a mixing vessel for containing the material to be mixed;
A spiral surface-shaped first stirring blade arranged in the mixing tank in _a rotatable state about a substantially horizontal axis L1;
A spiral surface-shaped second stirring blade arranged in the mixing tank in a rotatable state about an axis L ₂ substantially parallel to the axis L ₁ ,
When the first stirring blade and the second stirring blade are rotated in the direction of mixing the mixture (hereinafter referred to as "forward rotation"),
After the mixture is transferred from _one side in the direction of the axis L1 to the other side in the direction of the axis L1 by the _first stirring blade and then transferred to the side of the second stirring blade,
By the second stirring blade, the mixture to be mixed is transferred from the other side in the direction of the axis L ₂ to the one side in the direction of the axis L ₂ and transferred to the side of the first stirring blade,
Hereinafter, a twin-screw mixer in which the material to be mixed is mixed while being circulated in the mixing tank by repeating the transfer of the material to be mixed,
After the forward rotation washing mode in which the first stirring blade and the second stirring blade are washed while rotating the first stirring blade and the second stirring blade forward while washing water is stored in the mixing tank,
Execute a reverse rotation washing mode in which the first stirring blade and the second stirring blade are washed while rotating the first stirring blade and the second stirring blade in a direction opposite to the forward rotation (hereinafter referred to as "reverse rotation"). is solved by providing a twin-screw mixer characterized in that

In this way, after performing the forward rotation washing mode in which the first stirring blade and the second stirring blade are washed while rotating the first stirring blade and the second stirring blade forward while washing water is stored in the mixing tank, By performing a reverse rotation washing mode in which the first stirring blade and the second stirring blade are washed while rotating the first stirring blade and the second stirring blade in reverse, not only the mixture adhering to the front surface of the stirring blade but also the stirring It is also possible to wash off the mixture adhering to the back surface of the blade. In addition, in the twin-screw mixer of the present invention, structurally, it can be realized by simply changing the structure such that the first stirring blade and the second stirring blade can be reversely rotated.

However, in the twin-screw mixer, the first and second stirring blades, which form a spiral surface, rotate the first and second stirring blades in the forward direction so that the mixture is mixed as described above. It is designed in a shape that circulates, not in a shape that assumes reverse rotation. That is, as will be described in detail later, when the first stirring blade is reversely rotated, the mixture on the back side of the _first stirring blade is transferred from the other side in the direction of the axis L1 to the _one side in the direction of the axis L1. (Transported in the opposite direction to the above circulation direction) so as to be pressed against the inner wall surface on one side of the mixing tank (the inner wall surface arranged on _one side in the direction of the axis L1 and facing the _other side in the direction of the axis L1) Become. In addition, when the second stirring blade is reversely rotated, the mixture on the back side of the second stirring blade is transferred from one side in the direction of the axis L ₂ to the other side in the direction of the axis L ₂ (opposite to the above circulation direction direction) and is pressed against the inner wall surface on the other side of the mixing tank (the inner wall surface arranged on the other side in the direction of the axis L2 and facing _{one side} in the direction of the axis L2).

For this reason, when the reverse rotation cleaning mode is performed, the gap between the back surface around the end on _one side of the first stirring blade and the inner wall surface on one side of the mixing tank, and the axis L on the second stirring blade In the worst case, the twin-screw mixer may break down because the material to be mixed gets caught in the gap between the back surface around the end on the other side in the _two directions and the inner wall surface on the other side of the mixing tank. Therefore, in the twin-screw mixer of the present invention, when the reverse rotation washing mode is performed, the mixed material on the back side of the first stirring blade and the second stirring blade is moved to the front side of the first stirring blade and the second stirring blade. It is preferable to provide the first stirring blade and the second stirring blade with openings for escape to the side. As a result, it is possible to make it difficult for the mixed material to get caught in the gap when the reverse rotation cleaning mode is performed.

This escape opening not only contributes to preventing the mixed material from being caught, but also enables efficient cleaning of the first and second stirring blades in the forward rotation cleaning mode and the reverse rotation cleaning mode. do. That is, in the forward rotation washing mode, the washing water existing on the front surface side of the first stirring blade and the second stirring blade is guided to the back surface side of the first stirring blade and the second stirring blade through the escape opening, It becomes possible to wash the back side of the first stirring blade and the second stirring blade with the washing water. In the reverse rotation washing mode, the washing water existing on the back side of the first stirring blade and the second stirring blade is guided to the front side of the first stirring blade and the second stirring blade through the escape opening, It becomes possible to wash the front side of the first stirring blade and the second stirring blade with the washing water.

As described above, in the forward rotation washing mode, the back side of the first stirring blade and the second stirring blade can also be washed, so in the reverse rotation washing mode, the back side of the first stirring blade and one side of the mixing tank and the gap between the inner wall surface and the gap between the back surface of the second stirring blade and the inner wall surface on the other side of the mixing tank can be washed off in advance. It is also advantageous in that it is possible to more reliably prevent entrapment.

Although there is no particular limitation on the location where the escape opening is provided, it is preferably provided in the vicinity of the outer edge of the first stirring blade and the second stirring blade. This is because the material to be mixed around the rotating first stirring blade and second stirring blade is moved by the centrifugal force of the rotation to the side near the axis L1 and the axis L2 (the _first stirring blade and the _second stirring blade It moves from the inner edge side of the blade) to the far side (outer edge side of the first stirring blade and the second stirring blade). At this time, when too much of the mixture to be mixed moves to the vicinity of the outer edge of the first stirring blade and the second stirring blade, the mixture to be mixed is compressed near the outer edge of the first stirring blade and the second stirring blade, In some cases, the material to be mixed may get caught in the gap between the outer edges of the first and second stirring blades and the inner bottom surface of the mixing tank. In this regard, by providing the relief opening in the vicinity of the outer edge of the first stirring blade and the second stirring blade, the mixture is not compressed in the vicinity of the outer edge of the first stirring blade and the second stirring blade. It is possible to make it difficult for the mixture to be caught in the gap between the outer edge portions of the first stirring blade and the second stirring blade and the inner bottom surface of the mixing tank.

The dimensions of the release opening are not particularly limited, and vary depending on the type of mixture to be mixed. However, if the dimensions of the release opening are too small, the release opening may be clogged with the mixture to be mixed, and the release opening may not perform its function. Also, among the raw materials for ready-mixed concrete, the largest size is usually gravel. Gravel used as a raw material for ready-mixed concrete may have a particle size of about 40 mm if the size is large. Therefore, considering that the twin-screw mixer is also suitable for mixing ready-mixed concrete, the size of the escape opening is preferably 40 mm square or more. The upper limit of the dimensions of the escape opening is not particularly limited either. However, if the dimensions of the escape opening are too large, the escape opening will occupy a wide range of the first stirring blade and the second stirring blade, and the mixture will circulate through the first stirring blade and the second stirring blade. It may become difficult to transport. For this reason, it is preferable that the dimensions of the escape opening be 300 mm square or less.

The number of escape openings is also not particularly limited, but it is preferable to provide escape openings at a plurality of locations along the spiral of the first stirring blade and the second stirring blade. As a result, it is possible to more reliably prevent the aforementioned biting of the mixture to be mixed (in particular, the biting of the mixture to be mixed into the gap between the outer edge of the first stirring blade and the second stirring blade and the inner bottom surface of the mixing tank). be possible.

In the twin-screw mixer of the present invention, the switching from the forward rotation washing mode to the reverse rotation washing mode may be performed manually, but it is preferable that it be automatically performed by a program or the like. As a result, the first and second stirring blades can be cleaned even when no one is near the twin-screw mixer, reducing the labor required for cleaning the first and second stirring blades. it becomes possible to

As described above, the present invention provides a twin-screw mixer with a simple structure that can wash off not only the mixture adhering to the front surface of the stirring blade but also the mixture adhering to the back surface of the stirring blade. becomes possible. Another object of the present invention is to provide a method for cleaning the stirring blades in this twin-screw mixer.

1 is a perspective view showing a state in which a twin-screw mixer of the present invention is viewed obliquely from the upper right front; FIG. It is the figure which showed the state which looked at the twin-screw mixer of this invention from upper direction. FIG. 3 is a cross-sectional view showing a state of the twin-screw mixer of the present invention cut along the Y ₁ -Y ₁ plane in FIG. 2; FIG. 4 is a view for explaining the operation of kneading blades and switching blades in the twin-screw mixer of the present invention; Fig. 3 is a perspective view showing a state in which the first stirring blade in the twin-screw mixer of the present invention is viewed obliquely from the upper left front; Fig. 2 is a perspective view showing a disassembled state in which the first kneading blade is removed from the first stirring blade in the twin-screw mixer of the present invention, as viewed obliquely from the upper left front. FIG. 3 is a cross-sectional view showing a state in which the outer and inner blades of the twin-screw mixer of the present invention are cut along a plane perpendicular to the spiral direction; Fig. 3 is a flow chart showing an example of the procedure for washing the first stirring blade and the second stirring blade in the twin-screw mixer of the present invention.

A preferred embodiment of the twin-screw mixer of the present invention will be described more specifically with reference to the drawings. Figures 1 to 6 below show the x-, y-, and z-axes. The orientations of the x-, y- and z-axes are consistent with each other even in different views. In the following, for convenience of explanation, the x-axis direction positive side is the “right” side, the x-axis direction negative side is the “left” side, the y-axis direction positive side is the “rear” side, and the y-axis direction negative side is the “front” side. The positive side in the z-axis direction is called the "upper" side, and the negative side in the x-axis direction is called the "lower" side.

FIG. 1 is a perspective view of the twin-screw mixer of the present invention as seen obliquely from the upper right front. The twin-screw mixer of the present invention comprises a mixing tank 30, a first stirring blade 10, and a second stirring blade 20, as shown in FIG. The mixing tank 30 is a box-shaped member with an open upper surface so that the material to be mixed can be introduced into the inside through the open upper surface. At the bottom of the mixing tank 30, a mixture delivery port (not shown) for delivering the mixture finished mixing in the mixing tank 30 to the outside of the mixing tank 30 is provided in an openable/closable state.

The first stirring blade 10 and the second stirring blade 20 are for stirring and mixing the material to be mixed put into the mixing tank 30, and are arranged substantially parallel to each other at a predetermined interval in the left-right direction (x-axis direction). It is The first stirring blade 10 and the second stirring blade 20 have shaft-shaped front ends 10a and 20a supported by bearings (not shown) (bearings arranged outside the front wall 31 of the mixing vessel 30), The shaft-shaped rear ends 10b and 20b are supported by bearings (not shown) (bearings arranged outside the rear wall 32 of the mixing tank 30). The rear end portion 10b of the first stirring blade 10 and the rear end portion 20b of the second stirring blade 20 are connected to a rotation drive means (not shown) provided outside the mixing tank 30 . For this reason, the first stirring blade 10 and the _second stirring blade 20 rotate at the same speed _about the axes L1 and L2 parallel to the front-rear direction, respectively (arrows in FIG. 1). See A ₁ and arrow A ₂ ).

However, the direction in which the first stirring blade 10 rotates and the direction in which the second stirring blade 10 rotates are always opposite to each other. That is, when the first stirring blade 10 rotates in the direction of arrow A ₁₊ around the axis L ₁ (rotates counterclockwise around the axis L ₁ when viewed from the y-axis direction negative side), the first The _second stirring blade 20 rotates about the axis L2 in the direction of arrow _{A2 +} (rotates clockwise about the axis L2 when viewed from the negative side in the y-axis direction). On the other hand, when the first stirring blade 10 rotates in the direction of the arrow A _1- around the axis L ₁ (rotates clockwise around the axis L ₁ when viewed from the negative side in the y-axis direction), the first The second stirring blade 20 rotates in the direction of the arrow A _2- around the axis L ₂ (rotates counterclockwise around the axis L ₂ when viewed from the negative side in the y-axis direction). there is

Hereinafter, the rotation of the first stirring blade 10 in the direction of the arrow A ₁₊ and the rotation of the second stirring blade 20 in the direction of the arrow A ₂₊ are referred to as “forward rotation”, and the arrow in the first stirring blade 10 The rotation in the direction of A ₁₋ and the rotation in the direction of arrow A ₂₋ in the second stirring blade 20 are called “reverse rotation”. In the twin-screw mixer of the present invention, both the first stirring blade 10 and the second stirring blade 20 rotate forward when mixing the mixture in the mixing tank 30 . In the twin-screw mixer of the present invention, the first stirring blade 10 and the second stirring blade 20 are structured so as to rotate not only in the forward direction but also in the reverse direction. For this reason, as the rotation driving means for rotationally driving the first stirring blade 10 and the second stirring blade 20, a device capable of forward and reverse rotation (forward and reverse rotation motor, etc.) is used.

FIG. 2 is a top view of the twin-screw mixer of the present invention. As shown in FIG. 2, the first stirring blade 10 extends from the vicinity of the rear end portion 10b of the first stirring blade 10 to a portion closer to the front end portion 10a than the central portion in the front _- rear direction, with the axis line L1 as the center line. The first kneading blade 11 connected in a spiral surface shape, and the first stirring blade 10 from the part slightly closer to the front end 10a than the central part to the vicinity of the front end 10a, the axis line L ₁ spiral surface shape with the center line It has a first return blade 12 that continues to. The helical plane formed by the first kneading blade 11 and the helical plane formed by the first return blade 12 have opposite turning directions.

On the other hand, the second stirring blade 20 extends from the vicinity of the front end portion 20a of the second stirring blade 20 to a portion slightly closer to the rear end portion 20b than the central portion in the front _- rear direction, and has a spiral surface shape with the axis line L2 as the center line. The continuous second kneading blade 21 and the second stirring blade 20 from the part slightly closer to the rear end 20b than the central part to the vicinity of the rear end 20b are connected in a spiral plane shape with the axis line L ₂ as the center line. It has a two-turn blade 22. The turning direction of the spiral surface formed by the _second kneading blade 21 (the turning direction around the axis L2) is the turning direction of the spiral surface formed by the _first kneading blade 11 (the turning direction around the axis L1). , but opposite to the turning direction of the spiral surface formed by the _second turning blade 22 (the turning direction about the axis L2).

Therefore, as described above, the first stirring blade 10 and the second stirring blade 20 rotate forward (the first stirring blade 10 rotates in the direction of arrow A ₁₊ , the second stirring blade 20 rotates in the direction of arrow A ₂₊ ), the mixture in the mixing tank 30 is circulated and transferred in the directions of arrows B ₁ , B ₂ , B ₃ and B ₄ in FIG. 2 by the first stirring blade 10 and the second stirring blade 20. It has become so. The transfer indicated by arrow _B1 is mainly provided by the first kneading blade 11, the transfer indicated by arrow B2 is mainly provided by the first return blade 12 _, and the transfer indicated by arrow B3 is mainly provided for the _second kneading. The blade 21 is in charge, and the transfer of the arrow B4 is mainly in charge of the _second switching blade 22 .

By the way, when adopting a structure in which the first kneading blade 11 and the first return blade 12 constituting the first stirring blade 10 are attached to the outer peripheral portion of _a shaft that extends linearly along the axis L1, the shaft is covered. There is a risk of inhibiting the above-described circulatory movement of the mixture. Similarly, when adopting a structure in which the second kneading blade 21 and the second turning blade 22 constituting the second stirring blade 20 are attached to the outer peripheral portion of the shaft that extends linearly along the axis L2, the _shaft is covered There is a risk of inhibiting the above-described circulatory movement of the mixture. If the circulatory movement of the mixture to be mixed is inhibited, the mixing efficiency of the mixture to be mixed is reduced.

In this regard, both the first stirring blade 10 and the second stirring blade 20 in the twin-screw mixer of the present embodiment are linear shafts as described above ( _{linear shafts} extending along the axis L1 or the axis L2). It has a structure that does not have a shaft). That is, the first stirring blade 10 has the form shown in FIG. 5, and the first kneading blade 11 and the first return blade 12 that constitute the first stirring blade 10 are, as shown in FIG. It is adapted to be attached to the spiral arm 13 . FIG. 5 is a perspective view showing the first stirring blade 10 in the twin-screw mixer of the present invention as seen obliquely from the upper left front. FIG. 6 is a perspective view showing a disassembled state in which the first kneading blade 11 is removed from the first stirring blade 10 in the twin-screw mixer of the present invention, viewed obliquely from the upper left front.

As shown in FIG. 6, the spiral arm 13 includes a kneading blade mounting portion 13a on the rear end side, a turning blade mounting portion 13b on the front end side, a front end portion of the kneading blade mounting portion 13a, and a rear end portion of the turning blade mounting portion 13b. and a connecting portion 13c connecting the end portion in _a direction substantially perpendicular to the axis L1. The kneading blade mounting portion 13a is a portion for mounting the first kneading blade 11, and is formed in a spiral shape. The reversing blade mounting portion 13b is a portion for mounting the second kneading blade 12, and is formed in a helical shape in the opposite direction to the kneading blade mounting portion 13a. Although the second stirring blade 20 is not particularly illustrated, the second stirring blade 20 has a structure in which the front and rear of the first stirring blade 10 are reversed. By configuring the first stirring blade 10 and the second stirring blade 20 as described above, the above-described circulatory movement of the mixture to be mixed is efficiently performed.

The kind of the material to be mixed by the twin-screw mixer of the present invention is not particularly limited. However, in the twin-screw mixer, in addition to being able to mix while circulating the material to be mixed greatly within the mixing tank 30, as will be described later, the viscosity of the material to be mixed is high, and the fine particles contained in the material to be mixed are dispersed. Even if agglomerates are likely to form, the agglomerates can be sheared and finely mixed while being kneaded efficiently. Therefore, the twin-screw mixer of the present invention can be suitably used when mixing a mixture containing a viscous material. Examples of such materials to be mixed include high-fluidity concrete and high-strength concrete.

FIG. 3 is a cross-sectional view of the twin-screw mixer of the present invention taken along the plane Y ₁ -Y ₁ in FIG. As shown in FIG. 3, the lower wall portion (bottom wall portion) 33 of the mixing tank 30 has a shape in which two cylindrical surface portions 33a and 33b are connected. One cylindrical surface portion 33a is formed in a cylindrical surface shape centered on the axis L1, which is the rotation center of the _first stirring blade 10, and the other cylindrical surface portion 33b is formed on the second stirring blade 20. It is formed in a cylindrical shape around the axis _L2 , which is the center of rotation. While preventing the blades 11, 12, 21, 22 rotating around the axes L ₁ , L ₂ from interfering with the bottom wall 33 of the mixing tank 30, they adhere to the vicinity of the inner peripheral surfaces of the cylindrical surface portions 33a, 33b. The outer radii of the blades 11, 12, 21, 22 are set slightly smaller than the inner radii of the cylindrical surface portions 33a, 33b so that the blades 11, 12, 21, 22 reach the mixture to be mixed.

FIG. 4 is a diagram for explaining the operation of the first return blade 12 and the second kneading blade 21 in the twin-screw mixer of the present invention. FIG. 4 shows a cross section perpendicular to the y-axis, with some members omitted. Also, the first return blade 12 and the second kneading blade 21 are schematically drawn. Further, many small white circles drawn in FIG. 4 indicate the mixed material 90, and this mixed material 90 is also schematically drawn. Furthermore _, the mixture 90 is generally located below the curve L3 indicated by the thick dashed line in FIG. The illustration is omitted except for the part.

As shown in FIG. 4, the timing at which the _first return blade 12 passes the lowest point P1 of the cylindrical surface portion 33a and the timing at which the _second kneading blade 21 passes the lowest point P2 of the cylindrical surface portion 33b The timing is shifted, and when the first stirring blade 10 and the second stirring blade 20 rotate forward, the second kneading blade is rotated before the _first return blade 12 passes the lowest point P1. 21 passes through the lowest point _P2 . At this time, the material to be mixed 90 around the second kneading blade 21 is compressed by the second kneading blade 21 on the front surface side (A ₂₊ side) of the second kneading blade 21 and the pressure is increased. On the back surface side ( _A2- side) of the second kneading blade 21, the pressure becomes low. Similarly, the mixed material 90 around the first return blade 12 is compressed by the first return blade 12 on the front surface side (A ₁₊ side) of the first return blade 12 and the pressure is increased. On the other hand, the pressure on the back surface side (A ₁₋ side) of the first return blade 12 becomes low.

Under these circumstances, from the state shown in FIG. 4, the second kneading blade 21 rotates about 45 degrees to the forward rotation side (A ₂₊ side), and the first return blade 12 also rotates to the forward rotation side (A ₁₊ side), and when the outer end of the second kneading blade 21 faces the negative side in the x-axis direction, the lower side of the second kneading blade 21 (negative side in the z-axis direction) is the mixture 90 pressure is low. At this timing, the mixture 90 with high pressure on the front surface side (A ₁₊ side) of the first return blade 12 enters the lower side of the second kneading blade 21, so that the first return blade 12 The mixture 90 on the front surface side (A ₁₊ side) naturally flows into the second kneading blade 21 side. As a result, the transfer indicated by the arrow _B2 in the circulatory transfer described above is performed. The reason why the transfer indicated by the arrow _B4 in the circulatory transfer described above is performed is substantially the same as this.

As described above, in the twin-screw mixer of the present invention, a highly viscous mixture to be mixed can be efficiently mixed. It easily adheres to the blades 20 . If the mixture adhering to the first stirring blade 10 and the second stirring blade 20 is left as it is, the mixture will harden, and even if the first stirring blade 10 and the second stirring blade 20 are rotated forward, the mixture will remain above. , and the desired mixing effect may not be obtained. In addition, there is a risk that the first stirring blade 10 and the second stirring blade 20 will be damaged, and that the rotation driving means for rotating them will be out of order. In this regard, in the twin-screw mixer of the present invention, after its use (after mixing the mixture), the first stirring blade 10 and the second stirring blade 20 are washed, and the first stirring blade 10 and the second stirring blade The mixture (residue) adhering to 20 can be washed off.

FIG. 8 is a flow chart showing an example of the procedure for cleaning the first stirring blade 10 and the second stirring blade 20 in the twin-screw mixer of the present invention. In the twin-screw mixer of this embodiment, as shown in FIG. 8, a first washing water storing step S1, a forward rotation washing step S2, a first washing water discharging step S3, and a second washing water storing step S4. , the reverse rotation washing step S5 and the second washing water discharging step S6, the first stirring blade 10 and the second stirring blade 20 are washed. However, the configuration described below is merely an example, and can be modified as appropriate. For example, in the following description, it is written that "once the first washing water storing step S1 is finished, the forward rotation washing step S2 is subsequently executed." can be done in parallel with Further, in the following description, it is stated that "once the second wash water storing step S4 is completed, the reverse rotation cleaning step S5 is subsequently executed." can be done in parallel with

The first washing water storing step S1 is a step of storing in the mixing tank 30 the washing water for washing the first stirring blade 10 and the second stirring blade 20 in the subsequent forward rotation washing step S2. This first wash water storing step S1 is executed after finishing the mixing of the mixed material in the mixing tank 30 and delivering the mixed material from the mixing tank 30 through the mixed material delivery port. When executing the first wash water storing step S1, the mixed material delivery port in the mixing tank 30 is closed. Wash water is stored up to a height near the straight line _L4 in FIG. After finishing the first washing water storing step S1, the forward rotation washing step S2 is subsequently performed.

The forward rotation washing step S2 is a step of washing the first stirring blade 10 and the second stirring blade 20 while rotating the first stirring blade 10 and the second stirring blade 20 forward. This forward rotation cleaning step S2 is performed in a state where the cleaning water is stored in the mixing tank 30 (a state in which the cleaning water stored in the mixing tank 30 in the first cleaning water storage step S1 is not drained). As a result, the first stirring blade 10 and the second stirring blade 20 are washed with the washing water in the mixing tank 30 . During the forward rotation cleaning step S2, the cleaning water in the mixing tank 30 may decrease. In such a case, it is preferable to add the cleaning water even during the forward rotation cleaning step S2. .

In this forward rotation cleaning step S2, since the first stirring blade 10 and the second stirring blade 20 are rotated forward, water pressure is applied to the front side rather than the back side of the first stirring blade 10 and the second stirring blade 20. It is an easy situation. Therefore, in the forward rotation washing step S2, mainly the mixture (residue) adhering to the front surfaces of the first stirring blade 10 and the second stirring blade 20 is washed off.

The rotation speed of the first stirring blade 10 and the second stirring blade 20 in the forward rotation washing step S2 is not particularly limited, but if it is too slow, the washing action may deteriorate. For this reason, the rotational speeds of the first stirring blade 10 and the second stirring blade 20 are preferably 10 rpm or more. The rotational speeds of the first stirring blade 10 and the second stirring blade 20 are more preferably 20 rpm or higher, and even more preferably 25 rpm or higher.

On the other hand, if the rotational speeds of the first stirring blade 10 and the second stirring blade 20 in the forward rotation washing step S2 are too high, the washing water in the mixing tank 30 may splash around the twin-screw mixer. Moreover, there is a possibility that the mechanical vibration of the rotation driving means for rotating the first stirring blade 10 and the second stirring blade 20 may increase. For this reason, the rotational speeds of the first stirring blade 10 and the second stirring blade 20 are preferably 55 rpm or less. The rotational speeds of the first stirring blade 10 and the second stirring blade 20 are more preferably 45 rpm or less, and even more preferably 40 rpm or less.

The time for performing the forward rotation cleaning step S2 varies depending on the type of the mixture to be mixed, etc., and is not particularly limited, but is usually about 5 to 15 minutes. After finishing the forward rotation cleaning step S2, the first cleaning water discharge step S3 is performed.

The first washing water discharging step S3 is a step of discharging the washing water used for washing the first stirring blade 10 and the second stirring blade 20 in the normal rotation washing step S2 from the mixing tank 30. FIG. In the state where the forward rotation washing step S2 is finished, the mixture washed off from the first stirring blade 10 and the second stirring blade 20 is contained in the washing water. The dropped material to be mixed is discharged out of the mixing tank 30 together with the washing water. As a result, the reverse rotation cleaning step S5, which will be described later, can be performed using clean cleaning water. This first washing water discharge step S3 may be performed while the rotation of the first stirring blade 10 and the second stirring blade 20 is stopped, but it is performed while rotating the first stirring blade 10 and the second stirring blade 20. , it is possible to wash the first stirring blade 10 and the second stirring blade 20 even when the first washing water discharge step S3 is being performed. In this case, when the first stirring blade 10 and the second stirring blade 20 are rotated in the forward direction, the first stirring blade 10 and the second stirring blade 20 rake the mixture accumulated at the bottom of the mixing tank 30, It becomes possible to carry the mixture to the delivery port.

In the twin-screw mixer of this embodiment, the washing water in the first washing water discharging step S3 is discharged through the above-mentioned mixed material outlet, but is separately provided through a washing water outlet. You can do it. After the washing water in the mixing tank 30 is discharged and the first washing water discharging step S3 is completed, the second washing water storing step S4 is performed.

The second washing water storing step S4 is a step of storing in the mixing tank 30 the washing water for washing the first stirring blade 10 and the second stirring blade 20 in the subsequent reverse rotation washing step S5. Wash water is stored up to a height near the straight line _L4 in FIG. Thus, by replacing the cleaning water used in the reverse rotation cleaning step S5, the cleaning effect in the reverse rotation cleaning step S5 can be enhanced.

However, depending on the type of material to be mixed and the state of the washing water after the forward rotation washing step S2, the first washing water discharge step S3 and the second washing water storing step S4 may be omitted and the forward rotation washing step S2 may be omitted. The washing water used in the washing step S2 can also be reused in the reverse rotation washing step S5. After finishing the second washing water storing step S4, the reverse rotation washing step S5 is subsequently performed.

The reverse rotation washing step S5 is a step of washing the first stirring blade 10 and the second stirring blade 20 while rotating the first stirring blade 10 and the second stirring blade 20 in the reverse direction. This reverse rotation cleaning step S5 is performed while the cleaning water is stored in the mixing tank 30 (the cleaning water stored in the mixing tank 30 in the second cleaning water storage step S4 is not drained). As a result, the first stirring blade 10 and the second stirring blade 20 are washed with the washing water in the mixing tank 30 . The amount of cleaning water in the mixing tank 30 may decrease during the reverse rotation cleaning step S5 as in the forward rotation cleaning step S2. Washing water may be added even during step S5.

In this reverse rotation cleaning step S5, since the first stirring blade 10 and the second stirring blade 20 are rotated in reverse, water pressure is applied to the back side of the first stirring blade 10 and the second stirring blade 20 rather than the front side. It is an easy situation. Therefore, in the reverse rotation cleaning step S5, mainly the mixture (residue) adhering to the back surfaces of the first stirring blade 10 and the second stirring blade 20 is washed off. By performing this reverse rotation washing step S5, the mixture adhering to the first stirring blade 10 and the second stirring blade 20 is thoroughly washed off without separately washing with high-pressure washing water using a washing gun or the like. It is possible. Therefore, there is no need to incorporate a mechanism for controlling the cleaning gun or the like into the cover of the twin-screw mixer (not shown), thereby reducing costs.

The rotation speed of the first stirring blade 10 and the second stirring blade 20 in the reverse rotation washing step S5 is not particularly limited, but is usually the rotation speed of the first stirring blade 10 and the second stirring blade 20 in the forward rotation washing step S2. considered to be the same. However, as already described, the first stirring blade 10 and the second stirring blade 20, which form a spiral surface, rotate the first stirring blade 10 and the second stirring blade 20 in the forward direction. It is designed in a shape that circulates, not in a shape that assumes reverse rotation.

For this reason, in the reverse rotation cleaning step S5, if the first stirring blade 10 and the second stirring blade 20 are rotated at high speed from the beginning, the mixture to be mixed between the first stirring blade 10 and the second stirring blade 20 and the mixing tank There is a possibility that troubles such as being caught may occur. Therefore, in the reverse rotation cleaning step S5, the rotational speeds of the first stirring blade 10 and the second stirring blade 20 can be gradually increased from low speed. Such rotational speed control can be realized by using a device having an inverter function (inverter drive motor, etc.) as a rotational drive means for rotationally driving the first stirring blade 10 and the second stirring blade 20. can be done.

The time for performing the reverse rotation cleaning step S5 varies depending on the type of the mixture to be mixed, etc., and is not particularly limited, but is usually about 5 to 15 minutes. After the reverse rotation cleaning step S5 is completed, the second cleaning water discharge step S6 is subsequently performed.

The second washing water discharge step S6 is a step of discharging from the mixing tank 30 the washing water used for washing the first stirring blade 10 and the second stirring blade 20 in the reverse rotation washing step S5. In the state where the reverse rotation washing step S5 is finished, the mixture washed off from the first stirring blade 10 and the second stirring blade 20 is contained in the washing water. The dropped material to be mixed is discharged out of the mixing tank 30 together with the washing water. The discharge of washing water in the second washing water discharge step S6 can be performed in the same manner as in the above-described first washing water discharge step S3. However, when the second washing water discharge step S6 is performed while rotating the first stirring blade 10 and the second stirring blade 20, the first stirring blade 10 and the second stirring blade 20 are rotated forward instead of reversely. It is preferable to perform the second washing water discharge step S6 while

After the washing water in the mixing tank 30 is discharged and the second washing water discharge step S6 is completed, the washing of the first stirring blade 10 and the second diffusion blade 20 is completed. At this time, the first stirring blade 10 and the second stirring blade 20 are in a state where not only the mixed material adhering to the front surface but also the mixed material adhering to the back surface is washed off. , and is in a state in which the next mixing can be preferably performed.

The first cleaning water storage step S1, the forward rotation cleaning step S2, the first cleaning water discharge step S3, the second cleaning water storage step S4, the reverse rotation cleaning step S5, and the second cleaning water discharge step S6 described above are manually performed. (Performed by manipulating the operation unit provided in the twin-screw mixer), but in the twin-screw mixer of the present embodiment, steps S1 to S6 are automatically switched.

That is, the twin-screw mixer performs a first wash water storage mode for executing the first wash water storage step S1, a forward rotation washing mode for executing the forward rotation washing step S2, and a first wash water discharge step S3. a second washing water storage mode for executing a second washing water storage step S4; a reverse rotation washing mode for executing a reverse rotation washing step S5; and a second washing water discharge step S6. When the second washing water discharge mode is set, switching from the first washing water storage mode to the forward rotation washing mode, switching from the forward rotation washing mode to the first washing water discharge mode, and switching from the first washing water discharge mode to the first washing water discharge mode Switching from the water discharge mode to the second cleaning water storage mode, switching from the second cleaning water storage mode to the reverse rotation cleaning mode, and switching from the reverse rotation cleaning mode to the second cleaning water discharge mode are automatically performed by the program. It is designed to be done systematically. This makes it possible to save labor in cleaning the first stirring blade 10 and the second stirring blade 20 .

By the way, in the twin-screw mixer of the present invention, when the first stirring blade 10 and the second stirring blade 20 are reversely rotated in the reverse rotation cleaning step S5, the first stirring blade 10 and the second The second stirring blade 20 is designed to have a shape in which the mixture to be mixed circulates when the first stirring blade 10 and the second stirring blade 20 are rotated in the forward direction, and the shape is designed to rotate in the reverse direction. Not designed.

That is, when the first stirring blade 10 rotates forward, it is difficult for the mixture to be caught in the gap between the rear surface of the first kneading blade 11 and the inner surface of the rear wall portion 32 (FIG. 2) of the mixing tank 30. Then, when the first stirring blade 10 rotates in the reverse direction, there is a possibility that the material to be mixed is caught in the gap. Further, when the second stirring blade 20 rotates forward, the mixture is less likely to be caught in the gap between the back surface of the second kneading blade 21 and the inner surface of the front wall portion 31 (FIG. 2) of the mixing tank 30. Then, when the second stirring blade 20 rotates in the reverse direction, there is a possibility that the material to be mixed is caught in the gap.

Therefore, when the reverse rotation cleaning mode is performed, the gap between the back surface of the first kneading blade 11 and the inner surface of the rear wall portion 32 in the mixing tank 30, the back surface of the second kneading blade 21 and the front wall in the mixing tank 30 The material to be mixed is caught in the gap between the inner surface of the portion 31 and, in the worst case, the twin-screw mixer may be out of order. For this reason, in the twin-screw mixer of this embodiment, when the reverse rotation washing mode is performed, the material to be mixed on the back side of the first stirring blade 10 and the second stirring blade 20 is washed with the first stirring blade 10 and the second stirring blade 20. The first stirring blade 10 and the second stirring blade 20 are provided with escape openings α for escaping to the front side of the stirring blade 20, making it difficult for the mixture to be caught in the gap. The release openings α are provided in the vicinity of the outer edge portions of the first stirring blade 10 and the second stirring blade 20 in order to more favorably exhibit the effect of preventing jamming.

Moreover, the escape opening α not only prevents the mixture from being bitten, but also has the function of shearing the mixture when the mixture is mixed. That is, as shown in FIG. 4, when the first stirring blade 10 and the second stirring blade 20 are rotated forward to mix the mixture 90, the position on the front surface side (A 1 ₊ side) of the first stirring blade 10 The mixture 90 to be mixed passes through the escape opening α to the back surface side (A _1- side) of the first stirring blade 10, and the mixture located on the front surface side (A ₂₊ side) of the second stirring blade 20 90 passes through the back surface side ( _A2- side) of the second stirring blade 20 through the escape opening α. In other words, the mixture 90 located on the front surface side of the first stirring blade 10 and the second stirring blade 20 has a portion that remains on the front surface side and a portion that passes through the shearing opening α to the back surface side. , is sheared by the shearing opening α.

As already described, when the mixture 90 has a high viscosity, such as when the mixture 90 is high-fluidity concrete or high-strength concrete, fine particles contained in the mixture 90 remain as aggregates. Therefore, it is not easy to mix the mixture 90 to a homogeneous state in a short time. In this regard, in the twin-screw mixer of the present embodiment, as described above, the first stirring blade 10 and the second stirring blade 20 are provided with relief openings α so that the mixture 90 is sheared. , it is possible to shear (refine) aggregates of fine particles formed in the mixture 90 . Therefore, even if the mixture 90 has a high viscosity, the mixture 90 can be mixed to a homogeneous state in a short period of time.

As described above, the escape opening α is a portion through which the mixture 90 passes. Pass through the opening α. That is, when the forward rotation washing step S2 is performed, the washing water positioned on the front surface side (A ₁₊ side) of the first stirring blade 10 flows through the relief opening α to the back surface side of the first stirring blade 10 ( A _1- side), and the wash water located on the front surface side (A ₂₊ side) of the second stirring blade 20 flows through the relief opening α to the back surface side (A _2- side) of the second stirring blade 20. ). For this reason, when performing the forward rotation washing step S2, the washing water that has escaped to the back side of the first stirring blade 10 and the second stirring blade 20 through the escape opening α causes the first stirring blade 10 and the second stirring blade 20 to It is also possible to wash the back side of the second stirring blade 20 . Therefore, before performing the reverse rotation cleaning step S5, it is possible to wash off the mixture 90 adhering to the back surface side of the first stirring blade 10 and the second stirring blade 20 to some extent. It is possible to suppress biting of the mixture 90 during the step S5.

In addition, when performing the reverse rotation washing step S5, the washing water located on the back side (A _1- side) of the first stirring blade 10 flows through the escape opening α to the front side of the first stirring blade 10. (A ₁₊ side), and the wash water located on the back side (A _2- side) of the second stirring blade 20 flows through the relief opening α to the front side (A ₂₊ side) of the second stirring blade 20. ). For this reason, when performing the reverse rotation washing step S5, the first stirring blade 10 and the second stirring blade 20 are washed by the washing water that has escaped to the front surface side of the first stirring blade 10 and the second stirring blade 20 through the relief opening α. It is also possible to wash the front side of the second stirring blade 20 . Thus, the release opening α also has a function of enhancing the cleaning effect of the first stirring blade 10 and the second stirring blade 20 .

The number and arrangement of relief openings α are not particularly limited. Since it is also effective for cleaning the stirring blades 10 and the second stirring blades 20 , it is preferable to provide them at a plurality of locations along the spiral of the first stirring blades 10 and the second stirring blades 20 . Moreover, it is preferable that the escape opening α is provided not only in the first kneading blade 11 and the second kneading blade 21 but also in the first return blade 12 and the second return blade 22 . In the twin-screw mixer of this embodiment, each of the first kneading blade 11 and the second kneading blade 21 is provided with five relief openings α, and each of the first return blade 12 and the second return blade 22 Three escape openings α are provided.

The dimensions of the escape opening α are appropriately determined according to the type of the mixture 90 and the like. This is because, if the release opening α has a size that a material (the largest material) having the largest particle size among the materials to be mixed in the mixture 90 cannot pass through, the release opening α is clogged, This is because there is a possibility that the mixture 90 cannot pass through the release opening α. For this reason, the escape opening α is preferably sized to allow the maximum amount of material to pass through. For example, the largest material in ready-mixed concrete is usually gravel, and gravel mixed in ready-mixed concrete may have a particle size of about 40 mm if the size is large. For this reason, when mixing this kind of ready-mixed concrete, it is preferable that the relief opening α has a dimension of 40 mm square or more (a crossing dimension of 1 times or more the particle size of the maximum material), and 80 mm square. It is more preferable to have a dimension of 120 mm square or more (a crossing dimension of 3 times or more of the maximum material particle size). preferable.

On the other hand, if the dimension of the escape opening α is too large, the escape opening α will occupy a wide range in the first stirring blade 10 and the second stirring blade 20, and the mixture 90 will be difficult to circulate. There is fear. For this reason, when mixing the ready-mixed concrete, it is preferable that the escape opening α has a dimension of 300 mm square or less (a crossing dimension of 7.5 times or less than the particle size of the maximum material), and is 240 mm. It is more preferable to have a dimension of square or less (spanning dimension of 6 times or less than the particle size of the maximum material), and a dimension of 200 mm square or less (spanning dimension of 5 times or less of the particle size of the maximum material). More preferred. In the twin-screw mixer of this embodiment, the escape opening α is formed in a substantially rectangular shape with a width of about 130 mm in the inner and outer directions and a width of about 190 mm in the spiral direction. However, the escape opening α is not limited to a rectangle (a rectangle including a square), and may be other shapes such as other polygons (triangles, hexagons, etc.), circles, ovals, and the like.

The first kneading blade 11 and the first turning blade 12, and the second kneading blade 21 and the second turning blade 22 may each be configured by one member. However, in this case, if any of the blades 11, 12, 21, 22 is worn or damaged, it is necessary to replace the worn or damaged blades 11, 12, 21, 22 as a whole. be. Among the blades 11, 12, 21, 22, the outer edges of the blades 11, 12, 21, 22 are most likely to be worn or damaged. It is very uneconomical to replace 21 and 22 entirely.

For this reason, in the twin _- screw mixer of this embodiment, as shown in FIG. 40 and an inner blade 50 positioned closer to its center of rotation (axis line L ₁ ). In this way, by making the first kneading blade 11 separable into the outer blade 40 and the inner blade 50, it is possible to replace only the outer blade 40 and the inner blade 50 that are worn or the like. is now possible.

The first turning blade 12 of the first stirring blade 10 and the second kneading blade 21 and the second turning blade 22 of the second stirring blade 20 (not shown in FIG. 6) also have the same structure. In the following, the split structure of the first kneading blade 11 of the first stirring blade 10 will be mainly described, but the configuration related to the split structure described in the first kneading blade 11 is the first return blade 12 and the second kneading The blade 21 and the second switching blade 22 can be similarly employed.

FIG. 7 is a cross-sectional view showing a state in which the outer blade 40 and the inner blade 50 in the twin-screw mixer of the present invention are cut along a plane perpendicular to the spiral direction. In the twin-screw mixer of this embodiment, as shown in FIG. is fixed to a predetermined location on the spiral arm 13 so as to be attached to the outer edge portion of the spiral arm 13 . On the other hand, the inner blade 50 has a blade mounting bolt 14 inserted into a bolt insertion hole 50a provided therein, and the tip portion of the blade mounting bolt 14 is fixed to a predetermined position on the spiral arm 13, thereby extending the inner edge of the spiral arm 13. It is designed to be attached to a part. The bolt insertion hole 40a of the outer blade 40 is provided in an elongated hole shape extending in the inward and outward directions. is adjustable in the medial-lateral direction.

Although each of the outer blade 40 and the inner blade 50 described above may be formed of a single member, it is preferable to form each of them from a plurality of members. Also in the twin-screw mixer of this embodiment, as shown in FIG. It is composed of a plurality of inner blade division bodies 41 divided in the direction. This makes it possible to replace the outer blades 40 and the inner blades 50 in a narrower range (every outer blade segment 41 or each inner blade segment 51). In addition, the outer blade 40 and the inner blade 50 have a somewhat complicated shape, such as having unevenness that serves as the escape opening α. Although it is not always easy to form a spiral surface with one member, by configuring each of the plurality of outer blade divisions 41 and the plurality of inner blade divisions 51, the outer blade divisions 41 themselves and the inner blade divisions The blades 11, 12, 21, and 22 can be formed in a spiral plane while the body 51 itself has a relatively simple shape (planar shape). The escape opening α is formed at the boundary between the outer blade 40 and the inner blade 50 and between the adjacent outer blade segments 41, as indicated by the hatched portion in FIG. I'm trying

10 first stirring blade 11 first kneading blade 12 first turning blade 20 second stirring blade 21 second kneading blade 22 second turning blade 30 mixing tank 40 outer blade 41 outer blade divided body 50 inner blade 90 mixture L ₁ Axis line (rotation center of the first stirring blade)
L ₂ axis (rotation center of second stirring blade)
α Relief opening

Claims (7)

a mixing vessel for containing the material to be mixed;
A first kneading blade connected in a spiral plane with a substantially horizontal axis L ₁ as the center line, and a first return blade connected in a spiral plane in the opposite direction to the first kneading blade with the axis L ₁ as the center line A spiral surface-shaped first stirring blade arranged in the mixing tank in a rotatable state about the axis line L ₁ ,
A second kneading blade connected in a spiral plane shape with an axis line L ₂ substantially parallel to the axis line L ₁ as a center line, and a second kneading blade connected in a spiral plane shape in the opposite direction to the second kneading blade with the axis line L ₂ as the center line and a spiral surface-shaped _second stirring blade arranged in the mixing tank in a rotatable state about the axis L2 as the rotation center,
When the first stirring blade and the second stirring blade are rotated in the direction of mixing the mixture (hereinafter referred to as "forward rotation"),
After the mixture is transferred from _one side in the direction of the axis L1 to the other side in the direction of the axis L1 by the _first stirring blade and then transferred to the side of the second stirring blade,
By the second stirring blade, the mixture to be mixed is transferred from the other side in the direction of the axis L ₂ to the one side in the direction of the axis L ₂ and transferred to the side of the first stirring blade,
Hereinafter, a twin-screw mixer in which the material to be mixed is mixed while being circulated in the mixing tank by repeating the transfer of the material to be mixed,
a first wash water storage mode for storing wash water in the mixing tank;
A forward rotation washing mode in which the first and second stirring blades are washed for 5 to 15 minutes while rotating the first and second stirring blades forward while washing water is stored in the mixing tank ;
a first washing water discharge mode for discharging the washing water used in the forward rotation washing mode from the mixing tank;
a second wash water storage mode in which wash water is stored again in the mixing tank;
The first stirring blade and the second stirring blade are rotated in the direction opposite to the forward rotation (hereinafter referred to as "reverse rotation") while the washing water is stored in the mixing tank . a reverse rotation cleaning mode for cleaning the
A second washing water discharge mode that discharges the washing water used in the reverse rotation washing mode from the mixing tank.
A twin-screw mixer characterized in that it is capable of executing
When performing the reverse rotation washing mode, the release opening for releasing the mixture on the back side of the first stirring blade and the second stirring blade to the front side of the first stirring blade and the second stirring blade 2. The twin-screw mixer according to claim 1, wherein the first stirring blade and the second stirring blade are provided.
3. The twin-screw mixer according to claim 2, wherein the relief openings are provided on the outer edges of the first stirring blade and the second stirring blade.
4. The twin-screw mixer according to claim 2 or 3, wherein the escape opening has a size of 40 mm square or more.
The twin-screw mixer according to any one of claims 2 to 4, wherein the escape openings are provided at a plurality of locations along the spiral of the first stirring blade and the second stirring blade.
The twin-screw mixer according to any one of claims 1 to 5, wherein switching from the forward rotation washing mode to the reverse rotation washing mode is automatically performed.
A stirring blade cleaning method for cleaning the first stirring blade and the second stirring blade in the twin-screw mixer according to any one of claims 1 to 6.

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