JP7623575B2 - Method and device for preventing adhesion of kneaded raw materials in a vertical vacuum chamber of a vacuum extrusion molding device - Google Patents

Description

The present invention relates to a method for suppressing adhesion in the vacuum chamber of a vacuum extrusion molding device for carbon-containing agglomerates used in blast furnaces, and to the technology related to that device.

In a blast furnace, raw ore and lump coke are fed into the top of the furnace while air is blown in from the bottom. The reducing gas generated from the lump coke and the blown air is blown from the bottom to the top of the furnace, reducing and dissolving the iron oxide in the raw ore. To ensure the ventilation of the reducing gas in the furnace, the raw ore must be strong enough not to be pulverized in the furnace. For this reason, blast furnaces usually use raw materials that have been fired at high temperatures in advance, such as sintered ore or fired pellets.

In response to this, non-calcined agglomerates have been developed that use hydraulic binders such as cement to reduce the energy consumption required for calcination and reduce the amount of carbon dioxide, a greenhouse gas, produced. As the raw material for non-calcined agglomerates, it may be possible to use inferior fine ores that have been considered difficult to sinter and mold into agglomerates.

As described in Patent Document 1, it is possible to incorporate coke fines, which has a small particle size and is difficult to directly charge into a blast furnace, and anthracite, which is inexpensive but has low caking properties and is difficult to turn into coke, as reducing agents into non-calcined agglomerates, and it is expected that the reducing agent ratio in the blast furnace can be reduced. According to the latest findings, it is clear that the effect of reducing the reducing agent ratio in the blast furnace can be maximized by setting the carbon content (T.C.) incorporated in the non-calcined agglomerates to 120 to 200 mass% (equivalent to 15 to 25 mass% in T.C.) of the theoretical carbon amount required to reduce iron oxide to metallic iron.

Hydrates in non-sintered agglomerates formed by the hardening reaction of hydraulic binders are decomposed by an endothermic reaction when heated to approximately 400°C or higher in a blast furnace. This causes the strength of non-sintered agglomerates to decrease significantly in the furnace, raising concerns that they may pulverize. If non-sintered agglomerates pulverize in a blast furnace, it will worsen the air permeability inside the furnace, so a certain level of hot strength is required for non-sintered agglomerates for blast furnaces. On the other hand, if a large amount of hydraulic binder is used to ensure hot strength, the amount of reducing material input to the blast furnace will increase to compensate for the heat lost by the endothermic reaction, which will increase the cost of molten iron.

For these reasons, there is a demand for a manufacturing method for unsintered carbon-containing agglomerates that can achieve the hot strength required for blast furnace use with as little hydraulic binder as possible.

Recently, a manufacturing method that can achieve the hot strength required for blast furnace use has been developed that uses vacuum extrusion to produce unfired carbon-containing agglomerates for blast furnaces.

As shown in the example of Figure 1, the vacuum extrusion molding machine consists of a first extrusion section (mixing section) and a second extrusion section (extrusion molding section). In addition, the area from the outlet of the first extrusion section (mixing section) to the second extrusion section (extrusion molding section) is vacuum degassed to -40 kPaG or less to ensure the necessary strength of the molded body, and in order to stably continue vacuum extrusion molding, it is necessary to maintain the mixing raw material filling rate inside the mixing section and the extrusion molding section within an appropriate range. The appropriate value for the mixing raw material filling rate of the kneading section is 50 volume% to 90 volume%, and optimally, 50 volume% to 65 volume%. The appropriate value for the mixing raw material filling rate of the extrusion molding section is 50 volume% to 95 volume%, and optimally, 50 volume% to 60 volume%.

The filling rate of the raw material in the extrusion molding section 7 is generally monitored by an operator through a sight glass 10 installed at the top of the vacuum chamber 6. However, because a large amount of wet powder raw material 20 passes through the vacuum chamber 6, the raw material 20 adheres to the walls of the chamber and grows. When the adhesion of the raw material 20 grows beyond a certain level, it blocks the view from the sight glass 10, making it impossible to observe the extrusion molding section 7. In this case, it becomes necessary to stop operations and clean the inside of the vacuum chamber 6 (several hours to a dozen hours), which reduces the operating rate of the equipment.

This is because if regular monitoring becomes impossible, there is a concern that the equipment will continue to operate without noticing that the raw material filling rate has exceeded 95%, causing overloading or damage, resulting in a long-term equipment shutdown (several tens of hours to several days). Furthermore, if the raw material 20 adheres to the wall of the vacuum chamber 6 and the vacuum chamber 6 becomes blocked, the raw material supplied from the kneading weir 4d will no longer reach the extrusion molding section 7, making operation impossible. In this case, the equipment must also be stopped for internal cleaning. Therefore, in order to continue kneading molding stably, it is necessary to suppress the adhesion of the raw material 20 to the wall of the vacuum chamber 6. In general, the vacuum extrusion molding device to which the present invention is directed is cleaned inside periodically (every tens of hours to several days), so it is sufficient to suppress adhesion to an acceptable range (a level at which the inside can be observed) during this cleaning cycle.

Next, the difficulty of preventing adhesion to the walls of the vacuum chamber 6 will be explained. The vacuum chamber 6 is required to be highly airtight in order to maintain the vacuum degassing conditions (≦-40 kPaG) necessary to ensure product quality. Therefore, even if a rubber plate 11 or the like is attached to cover the walls of the vacuum chamber 6, it is difficult to pulsate the rubber plate 11 from the outside using mechanical force or pressure caused by the introduction of a fluid (air, etc.). In addition, it is desirable to avoid opening and cleaning the vacuum chamber 6 periodically at relatively short intervals (for example, every few hours) as this leads to a decrease in the operating rate.

Therefore, in order to prevent adhesion to the walls of the vacuum chamber 6, a method is required that can be implemented without applying mechanical or compressed air forces from outside the vacuum chamber 6. Furthermore, the raw material 20 that is the subject of the present invention is wet (a few percent to a dozen percent moisture) and contains a large amount of fine powder (for example, powder of ≦100 μm), so it easily adheres to the walls of the device.

Conventionally, the walls of the vacuum chamber 6 are cleaned by operators by shutting down the equipment periodically (every 10 hours to several days) or whenever adhesion growth is confirmed (at the earliest several hours after the regular cleaning). If cleaning becomes necessary in a short period of time (for example, several hours) due to some reason (high moisture content of raw materials, high fine powder content, etc.), this leads to a large increase in the workload and a decrease in the equipment operating rate.

Therefore, various measures to prevent adhesion have been considered. For example, as described in Patent Documents 2 to 7, there is a method in which liners or sheets installed in chutes or conveyor transfer sections are vibrated or rocked in some way.

Specific methods for moving the sheet or liner include, for example, a method in which a sheet or liner that is only partially fixed is mechanically impacted from the outside, as described in Patent Documents 2 and 3.

However, because the sheet is mechanically pressed from the outside, the vacuum chamber 6 does not maintain airtightness, making this difficult to apply. In addition, it is not realistic to install new vibration generating devices or mechanically operated devices, as it would be difficult in terms of equipment space and there is a high concern that operating devices will soon become inoperable due to dust adhesion.

Also, as described in Patent Documents 5 to 7, there is a method in which a fluid is introduced between the inner wall of the device and the sheet or liner to move the sheet or liner and remove the deposits.

However, the vacuum chamber is under strong negative pressure (approximately -100 kPa to 40 kPa) to maintain vacuum degassing conditions, so if fluid leaks into the vacuum chamber, the equipment (including not only the vacuum chamber and extrusion molding device, but also peripheral equipment such as the vacuum pump) may be damaged due to large pressure fluctuations, which is not desirable.

Furthermore, in Patent Document 4, the sheet material, whose upper end is fixed only at the conveyor transfer section, is supported from the rear, so that the sheet material is deflected by the impact of the conveyor-transported raw material colliding with it from the front, making it difficult for the colliding raw material to adhere to it.

However, in the vacuum chamber 6 where the raw material falls almost vertically, the impact force of the raw material alone is not enough to bend the sheet material sufficiently, and the adhesion suppression effect of this method is not sufficient.

A specific example of the kneading and molding of non-sintered agglomerates according to the present invention will be described below. In the kneading and molding of powder, the raw materials required for the production of non-sintered agglomerates and, if necessary, an appropriate amount of moisture are added to the kneading section, and the powdered raw materials are kneaded with the kneading blades and screws in the device.

The raw material is then extruded in the extrusion molding section in the subsequent process. There are various types of kneading and molding devices, but when kneading and molding raw materials continuously and in large quantities (for example, several tons/hr or more), a non-calcined agglomerate kneading and molding machine is often used, which is composed of a kneading section 4 that uses kneading blades 4c (sometimes a screw) attached to a horizontally installed single-shaft or multi-shaft kneading shaft 4b to continuously transport and knead the raw material 20 in the horizontal direction, and an extrusion molding section 7 that extrudes the raw material 20 from an extrusion molding weir 7d with an extrusion molding blade 7c (sometimes a screw) to mold it, as shown in the example in Figure 1. In the example shown in Figure 1, the extrusion molding section 7 transports the raw material by the extrusion molding blade 7c inside the casing 7a, and this extrusion molding blade 7c is provided on the rotatable extrusion molding section shaft 7b.

Patent No. 5000402 Japanese Patent Application Publication No. 10-311682 Patent No. 5287153 Japanese Patent Application Publication No. 10-279061 Japanese Utility Model Application Publication No. 1-169520 Japanese Utility Model Application Publication No. 5-68944 Registered Utility Model No. 3214008

The present invention provides an easy and low-cost method and device for preventing adhesion of mixed raw materials to the vacuum chamber walls in a vacuum extrusion molding device for carbon-containing agglomerates for blast furnaces.

A method for suppressing adhesion of a kneaded raw material in a vertical vacuum chamber of a vacuum extrusion molding apparatus for solving the above problems includes the following steps:
(1) In a vertical vacuum chamber of a vacuum extrusion molding apparatus for non-sintered agglomerates, one or more long rubber or resin plates are fixed at only their upper ends to the upper part of the vertical vacuum chamber, and the long plates are hung down with a gap between them and the vertical vacuum chamber inner wall, thereby preventing the raw materials from adhering to the vertical vacuum chamber inner wall.

Also,
(2) In (1), a rotating blade that comes into rotating contact with the long plate is installed in the vertical vacuum chamber of the kneading shaft installed in the vacuum extrusion molding device, thereby striking the long plate and causing the kneaded raw material adhering to the long plate to fall.

Also,
(3) In (1) or (2), the lower end of the long plate is lower than the lower end of the kneading gate of the vacuum extrusion molding device and higher than the center of the extrusion molding shaft.

Furthermore, as a device for suppressing adhesion of the kneaded raw material in the vertical vacuum chamber of the vacuum extrusion molding device,
(4) In a vertical vacuum chamber of a vacuum extrusion molding apparatus for non-sintered agglomerates, one or more long plates made of rubber or resin are fixed to an upper portion of the vertical vacuum chamber at only their upper ends, and the long plates are hung down with a gap between them and an inner wall of the vertical vacuum chamber.

moreover,
(5) In the above (4), a rotating blade that comes into rotating contact with the long plate is installed in the vertical vacuum chamber of a kneading shaft installed in the vacuum extrusion molding device.

moreover,
(6) In (4) or (5), the lower end of the long plate is located below the lower end of the kneading gate of the vacuum extrusion molding device and above the center of the extrusion molding shaft.

The present invention provides a method and device for suppressing adhesion in the vacuum chamber of a vacuum extrusion molding device, which can significantly suppress adhesion of mixed raw materials to the walls of the vacuum chamber, allowing stable continuous operation for more than 10 hours, for example, and significantly increasing the number of operating days, which is of great technical significance.

FIG. 1 is a schematic diagram of a vacuum extrusion molding machine. FIG. 13 is a diagram showing an outline of the adhesion state of the raw material to be kneaded in the vacuum chamber. FIG. 13 is a diagram showing the installation of rubber plates and the like in a vacuum chamber. FIG. 13 is a diagram showing an example of a rotating blade that strikes a rubber plate or the like. 1A to 1C are diagrams showing the state of installation of rubber plates etc. before operation, the state of the vacuum chamber during operation, and the moment when the rotating blades come into contact with the rubber plates etc. and give an impact.

The following is a form for implementing the invention.

The present invention provides a method for preventing the adhesion of raw materials to the walls of the vacuum chamber 6 by using one or more long rubber plates 11 (natural rubber plates, synthetic rubber plates, thin resin plates, other flexible sheets or liners, etc.) fixed to the inner wall of the vacuum chamber 6 with only their upper ends fixed thereto, and more preferably by using a rotating blade 12 that is installed in the vacuum chamber 6 portion of the kneading shaft 4b and has the function of scraping off the raw materials adhering to the rubber plates 11 while pulsating the entire rubber plates 11, causing the raw materials adhering to the entire rubber plates 11 to peel off.

An example of the structure near the kneading section 4 of this technology is as shown in FIG. 1, where the raw material 20 sent from the mixer 1 is fed into the raw material inlet 2. The raw material 20 fed into the raw material inlet 2 is led to the kneading section 4 through the connecting pipe 3, and is kneaded using the kneading blades 4c and other components provided on the shaft 4b. A raw material compaction section 4e is provided in front of the weir 4d from which the raw material is pushed out. In addition, an internal observation section 4f such as a grating is provided at the top of the kneading section 4, and water can be sprayed from the water-adding nozzle 5 through this section onto the raw material 20 in the casing 4a. A vacuum chamber 6 leading to the extrusion molding section 7 is provided beyond the kneading section 4, and a vacuum pump 8 is connected to this vacuum chamber 6 via a vacuum pump connection pipe 9. A viewing window 10 is provided at the top of this vacuum chamber 6. Below, a rubber plate or the like 11 and a rotating blade 12 provided in the vacuum chamber 6 will be described.

1) Rubber plates, etc. 11 Fig. 2 shows an outline of the adhesion state of the raw material in the vacuum chamber 6. The adhering raw material 21 to which the raw material 20 adheres inside the vacuum chamber 6 is most noticeable on the left and right wall surfaces (left and right wall surfaces) of the kneading weir 4d. This is because the raw material 20 discharged from the kneading weir 4d falls so as to spread out to the left and right. In particular, the left and right wall surfaces at the position corresponding to the range from the center to the lower end of the kneading weir 4d are prone to adhesion due to scattering of fine powder raw material and water vapor discharged from the kneading weir 4d, and the adhesion and growth of the raw material 20 is most noticeable on all the wall surfaces.

On the other hand, the wall surface (entrance side wall surface) of the vacuum chamber 6 facing the kneading weir 4d, through which a large amount of raw material 20 always passes, and the outlet side wall surface (the surface facing the inlet side wall surface) that is relatively far from the kneading weir 4d, have relatively little raw material adhering to them. Therefore, measures to prevent adhesion to the wall surfaces of the vacuum chamber 6 are most necessary on the left and right walls, and it is desirable to install rubber plates, etc. 11 in at least two places on the left and right walls.

In addition, rubber plates or the like 11 may be installed on the inlet wall surface or the outlet wall surface. If they are installed, the shape of the rubber plates or the like 11 may be processed so as to avoid the kneading weir 4d and the kneading shaft 4b.

2) Attached raw material to be kneaded Fig. 3 shows a method of installing the rubber plate 11. One or more rubber plates 11 may be used, and a single rubber plate 11 may have multiple cuts or slits to hang down. This rubber plate 11 is fixed only at its upper end to the inner wall of the vacuum chamber 6, and the other part is free (not fixed to the inner wall of the vacuum chamber 6). The upper end does not have to be completely the upper end, and may be an upper end part that is lower than the upper end by several mm to several tens of mm depending on the situation.

Details of the rubber plate 11 will be described later, but simply installing this rubber plate 11 will have a certain effect, as the falling raw material 20 collides with the rubber plate 11 and the raw material 21 adhering to the rubber plate 11 falls off due to the impact. Furthermore, if the rubber plate 11 is pulsated by contact with the rotating blades 12 (described later) and the raw material 21 adhering to the rubber plate 11 falls off, an even greater effect can be obtained.

The present invention will be described in detail below. In order for the rubber plate or the like 11 to pulsate, it is necessary to provide a gap (for example, a few mm to a few tens of mm; taking into account the capacity of the vacuum chamber 6, a gap of about 5 to 50 mm from the inner wall of the vacuum chamber 6 is preferable) between the rubber plate or the like 11 and the inner wall of the vacuum chamber 6.

Next, the upper and lower limits of the fixed position (upper end) and lower end of the rubber plate, etc. 11 will be explained. The lower limit of the fixed position (upper end) of the upper end of the rubber plate, etc. 11 is higher than the center of the kneading shaft 4b. This is to cover the position where the raw material adhesion is most severe (from the center to the lower end of the kneading weir 4d).

Due to the structure of the equipment, the upper limit of the fixed position (upper end) of the rubber plate, etc. 11 is the upper end of the vacuum chamber 6. The fixed position (upper end) of the upper end of the rubber plate, etc. 11 may be determined arbitrarily as long as it is within this range (from the center of the kneading shaft 4b to the upper end of the vacuum chamber 6), but considering the reduction of the risk of the rotating blades 12 coming into contact with the fixed rubber plate, etc. 11 and damaging the device, and the prevention of adhesion of the raw material 20 to the wall surface, it is more preferable to set the fixed position (upper end) in the range from the upper end of the vacuum chamber 6 to the upper end of the kneading weir 4d.

Next, the position of the bottom end of the rubber plate 11 will be explained. The bottom end of the rubber plate 11 must be at least lower than the bottom end of the kneading weir 4d. This is because, as mentioned above, the raw material 20 is most likely to adhere to the wall surface corresponding to the center to the bottom end of the kneading weir 4d.

On the other hand, it is desirable that the lower end of the rubber plate 11 be located above the center of the extrusion shaft 7b. This is to prevent the rubber plate 11 from being caught in the rotation of the extrusion blade 7c or the extrusion shaft 7b and being damaged. The position of the lower end of the rubber plate 11 may be determined arbitrarily within this range (the lower end of the kneading weir 4d to the center of the extrusion shaft 7b).

The material of the rubber plate 11 is not particularly limited as long as it is natural rubber, synthetic rubber, thin resin, or any other flexible sheet or liner. It is preferable that the rubber plate 11 is a one-piece material without seams or other irregularities. This is because if the rubber plate 11 has irregularities, these will likely become the starting points for the kneaded and attached raw material 21.

The rubber plate 11 of the present invention is also easy to maintain. The rubber plate 11 can be easily removed from the device by opening the top of the vacuum chamber 6, and can be cleaned. This is because the rubber plate 11 is fixed only at the top end, and can be lifted up from the top of the vacuum chamber 6 by removing only the top fixing part. Usually, the bottom of the vacuum chamber 6 is covered with a strong liner, and it is difficult to install a large inspection window, so if the rubber plate 11 is fixed at the bottom of the vacuum chamber 6, it takes a lot of time and effort to remove it. On the other hand, the top of the vacuum chamber 6 is generally designed to be openable for inspection and cleaning.

3) Rotating blade 12 The rotating blade 12, which is one of the preferred embodiments of the present invention, and its use will be described. The shape of the rotating blade 12 is arbitrary, and it is sufficient that the blade has a structure that can apply impact periodically to the rubber plate 11 or the like.

Here, it is preferable that the tip portion of the rotating blade 12 that comes into contact with the rubber plate or the like 11 is wider. This is because when the tip of the rotating blade 12 comes into contact with the rubber plate or the like 11, not only does it pulsate the rubber plate or the like 11 to cause the adhering raw material 21 to peel off, but it is also expected to have the effect of scraping off the adhering raw material 21 on the rubber plate or the like 11.

On the other hand, it is preferable that the area of the rotating blades 12 other than the part that contacts the rubber plate or the like 11 is as small as possible within the range that maintains the necessary structural strength. This is to improve visibility when the worker observes through the sight window 10. At least one or more rotating blades 12 are required. On the other hand, if there are a large number of rotating blades 12, the rotating blades 12 tend to interfere with the field of view of the worker when monitoring the inside of the vacuum chamber 6 or the extrusion molding section 7 through the sight window 10, making the monitoring work difficult. Furthermore, there is a concern that the rotating blades 12 themselves may become the starting point for the adhesion of the raw material to be kneaded to the kneading shaft 4b. Therefore, it is preferable to have fewer rotating blades 12. As a result of the investigation, it is most preferable to have about 1 to 4 rotating blades 12.

The size of the rotating blades 12 need only be within a size that allows them to rotate within the vacuum chamber 6, and at least be large enough to impact the rubber plate 11 (at least large enough to come into contact with the rubber plate 11).

Figure 4 shows four examples of the rotating blades 12. However, the rotating blades 12 are not limited to these four examples. 1) in Figure 4 has one flat rotating blade 12 installed. 2) and 3) in Figure 4 have two and four cylindrical or prismatic rotating blades 12 installed, respectively. 4) in Figure 4 is a rotating blade 12 with a special shape in which only the part that comes into contact with the rubber plate or the like 11 is widened, which has the effect of scraping off the adhering raw material 21 when the rotating blade 12 comes into contact with the rubber plate or the like 11, while also improving visibility when the worker visually monitors.

When rubber plates or the like 11 are installed on the inlet and outlet walls of the vacuum chamber 6, it is difficult for the rotating blades 12 to impact the rubber plates or the like 11. However, the adhesion of the raw material 20 to the inlet and outlet walls is less than that to the left and right walls. Therefore, the adhesion of the raw material 20 to the inlet and outlet walls can be sufficiently suppressed by the pulsation generated by the raw material 20 colliding with the rubber plates or the like 11.

In the present invention, by using the rotating blades 12 installed on the kneading shaft 4b, it is possible to apply force to the rubber plate 11, etc., without a mechanism that applies an impact to the rubber plate 11 from outside the vacuum chamber 6. Therefore, it is possible to pulsate the rubber plate 11 while maintaining the airtightness of the vacuum chamber 6. In addition, the rotating blades 12 themselves can be made small, so they can be easily installed in the limited space of the vacuum chamber 6, and the costs of installation and maintenance are low.

The above-mentioned anti-adhesion method using rubber plates 11 and rotating blades 12 can be easily and inexpensively implemented to prevent the raw material from adhering to the walls of the vacuum chamber 6, allowing for stable and continuous vacuum extrusion molding.

Figure 5 shows an example. 1) in Figure 5 shows the state in which the rubber plate 11 is installed before operation. 2) and 3) in Figure 5 show the state of the vacuum chamber 6 during operation, and 3) shows the moment when the rotating blade 12 comes into contact with the rubber plate 11 and gives an impact. Note that Figure 5 shows the configuration in which one rotating blade 12 is installed as in 1) of Figure 4 above, and is rotating at 20 to 30 revolutions per minute.

REFERENCE SIGNS LIST 1 Mixer 2 Feeding port 3 Connecting pipe 4 Kneading section 4a Casing 4b Kneading shaft 4c Kneading blade 4d Kneading weir 4e Kneading raw material consolidation section (where the raw material is consolidated before the weir and kneading is particularly prominently performed)
4f Internal observation section on the top of the kneader (grating, glass window, opening, etc.)
5 Water adding nozzle 6 Vacuum chamber 7 Extrusion molding section 7a Casing 7b Extrusion molding shaft 7c Extrusion molding blade 7d Extrusion molding gate 8 Vacuum pump 9 Vacuum pump connection tube 10 Sight window 11 Rubber plate, etc. 12 Rotating blade 20 Raw material to be kneaded

Claims (4)

In a vertical vacuum chamber of a vacuum extrusion molding apparatus for non-calcined agglomerates, one or more long rubber or resin plates are fixed at only the upper ends of the long plates to an upper portion of the vertical vacuum chamber, and the long plates are hung down with a gap between them and a wall of the vertical vacuum chamber to prevent the raw material to be kneaded from adhering to the wall of the vertical vacuum chamber ;
A rotating blade that is in rotational contact with the long plate is installed in a vertical vacuum chamber of a kneading shaft installed in a vacuum extrusion molding device,
This method for suppressing adhesion of kneaded raw material in a vertical vacuum chamber of a vacuum extrusion molding device is characterized in that the long plate is struck and the kneaded raw material adhering to the long plate falls . 2. A method for suppressing adhesion of raw material to be mixed in a vertical vacuum chamber of a vacuum extrusion molding apparatus according to claim 1 , wherein the lower end of the long plate is lower than the lower end of a mixing gate of the vacuum extrusion molding apparatus and higher than the center of the extrusion molding shaft. In a vertical vacuum chamber of the vacuum extrusion molding apparatus for non-calcined agglomerates, one or more long rubber or resin plates are fixed at only their upper ends to an upper portion of the vertical vacuum chamber, and the long plates are hung down with a gap between them and an inner wall of the vertical vacuum chamber ;
A device for suppressing adhesion of kneaded raw materials in a vertical vacuum chamber of a vacuum extrusion molding device, characterized in that a rotating blade that rotates and comes into contact with the long plate is installed in the vertical vacuum chamber portion of a kneading shaft installed in the vacuum extrusion molding device. 4. A device for suppressing adhesion of kneaded raw material in a vertical vacuum chamber of a vacuum extrusion molding device according to claim 3 , wherein the lower end of the long plate is located below the lower end of the kneading weir of the vacuum extrusion molding device and above the center of the extrusion molding shaft.