Method and device for measuring and managing the level of mixed raw materials in a vacuum chamber using images

Abstract

To provide an apparatus for measuring a kneaded raw material level and a management method for a kneaded raw material level that use images and detect a rise of a kneaded raw material level in an extrusion-molding unit early, as a measurement method and a measurement device which can quickly determine a rise of a kneaded raw material level in an extrusion-molding part 7 in a vacuum extrusion-molding apparatus.SOLUTION: A method for measurement and management a kneaded raw material level inside a vacuum chamber and an apparatus thereof are provided. A kneaded raw material inlet, a connection pipe which directs a kneaded raw material to a kneading unit, a kneader in which a shaft equipped with an impeller is arranged, a weir onto which a kneaded raw material is extruded, a vacuum chamber, and an extrusion-molding unit are arranged in this order. A peephole is disposed in an upper part of the vacuum chamber, and a light arranged on the peephole illuminates a kneaded raw material at a lower part inside the vacuum chamber through the peephole. An imaging device arranged on the peephole images the kneaded raw material level at the lower part inside the vacuum chamber, thereby a rise of a kneaded raw material level is observed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method and device for measuring and managing the level of raw materials to be mixed in a vacuum chamber using images. [Background technology]

[0002] In a blast furnace, raw ore and lump coke are charged from the top of the furnace while air is blown from the bottom of the furnace. 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. In order to ensure the ventilation of the reducing gas in the furnace, the raw ore is required to have a strength that does not powder in the furnace. For this reason, raw materials that have been fired at high temperatures in advance, such as sintered ore and fired pellets, are usually used in blast furnaces.

[0003] 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, generated. As the raw material for non-calcined agglomerates, it may be possible to use inferior fine ores that have been considered to have low sinterability and are difficult to mold into agglomerates.

[0004] Furthermore, as described in Patent Document 1, 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 convert into coke, can be mixed as reducing agents into non-calcined agglomerates, and it is expected that the reducing agent ratio of the blast furnace can be reduced.The latest findings reveal that the effect of reducing the reducing agent ratio in a blast furnace can be maximized by setting the carbon content (TC) incorporated in the non-calcined agglomerates to 120 to 200 mass% (equivalent to 15 to 25 mass% in TC) of the theoretical carbon amount required to reduce iron oxide to metallic iron.

[0005] The hydrates in the non-sintered agglomerates formed by the hardening reaction of the hydraulic binder are decomposed by an endothermic reaction when heated to about 400°C or higher in a blast furnace. This causes the strength of the non-sintered agglomerates to decrease significantly in the furnace, and there is a concern that they may be pulverized. If the non-sintered agglomerates are pulverized in the blast furnace, it will deteriorate the 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, and the cost of molten iron will increase.

[0006] In view of the above, there is a demand for a method for producing unsintered carbon-containing agglomerated ore that can achieve the hot strength required for use in a blast furnace with as little hydraulic binder as possible.

[0007] Recently, a manufacturing method that can achieve the hot strength required for blast furnace use has been developed, which uses a vacuum extrusion method to manufacture unbaked carbon-containing agglomerates for blast furnace use.

[0008] 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 below -40 kPaG to ensure the necessary strength of the molded body, and in order to stably continue vacuum extrusion molding, it is necessary to maintain the filling rate of the kneaded raw material inside the kneading section and the extrusion molding section within an appropriate range. The appropriate value for the filling rate of the kneaded raw material in the kneading section is 50% by volume or more and 90% by volume or less, and optimally 50% by volume or more and 65% by volume or less. The appropriate value for the filling rate of the kneaded raw material in the extrusion molding section is 50% by volume or more and 95% by volume or less, and optimally 50% by volume or more and 60% by volume or less.

[0009] Here, if the level of the raw material in the extrusion molding section rises and the raw material filling rate exceeds 95% by volume, there is a concern that the device may stop or be damaged due to overload. If such a situation occurs, the device will have to be stopped for a long period of time (for example, several hours to several days) to remove the raw material 20 from the device, clean the device, repair the device, etc., and the device's operating rate will drop significantly. Therefore, in order to continue the mixing and molding stably, it is important to quickly detect an increase in the raw material filling rate in the extrusion molding section by constantly monitoring the rise in the raw material level.

[0010] In a vacuum extrusion molding device, the only place where the level of the raw material in the extrusion molding section can be observed is generally a sight glass installed at the top of the vacuum chamber connecting the kneading section and the extrusion molding section. This is because the extrusion molding section and the vacuum chamber are covered with liners to evacuate the inside of the device, and the internal conditions cannot be observed from the outside. In particular, the extrusion molding section needs to be covered with strong liners on the top, bottom, left and right sides to consolidate the raw material, so a sight glass or the like cannot be installed. In addition, since the wet raw material 20 flows inside the extrusion molding section and the vacuum chamber, even if a level meter (contact type or non-contact type) is installed inside the device, the raw material will soon adhere to the sensor, making accurate measurement impossible.

[0011] Generally, the raw material level in the extrusion molding section is monitored visually by an operator periodically through a sight glass in the upper part of the vacuum chamber. However, because the raw material level in the extrusion molding section can rise to the point where the equipment is overloaded and shuts down within a few tens of seconds to a few minutes, regular monitoring by operators often results in missed increases in the raw material level, or delayed response due to differences in judgment between operators.

[0012] Also, in the prior art, there is a technique for measuring the raw material level by a laser projector and a receiver installed above the observation window (Patent Documents 2 and 3). However, the accuracy of measurements using laser light is easily reduced by dust and steam generated from the raw material 20 inside the device. In addition, even if one tries to simply measure the raw material level in the extrusion molding section using laser light (Patent Documents 2 and 3), the raw material 20 supplied from the kneading section and falling inside the vacuum chamber interferes with the laser light, and the height of the falling raw material 20 is detected instead of the raw material level in the extrusion molding section, which is what is actually being measured.

[0013] Here, in an environment where dust and steam are generated, such as the one targeted by the present invention, it is generally known that microwave level meters and millimeter wave level meters can measure the raw material level with relatively high accuracy. However, even if the laser projector and receiver of Patent Document 2 and Patent Document 3 are simply replaced with a microwave level meter or the like, it is difficult to stably measure the raw material level in the extrusion molding section. This is because, even when a microwave level meter or the like is used, interference from the raw material falling inside the vacuum chamber occurs.

[0014] Further, the kneading and molding of non-calcined agglomerates will be specifically described. In the kneading and molding of powder, the raw material 20 and, if necessary, water are put into the kneading section, and the powder raw material is kneaded by the kneading blades and screws in the device. After that, the raw material 20 is extruded and molded in the extrusion molding section in the subsequent process. There are various types of kneading and molding devices, but when kneading and molding the raw material 20 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 generally composed of a kneading section 4 of a type that kneads the raw material 20 while continuously conveying it in the horizontal direction using kneading blades 4c (which may be screws) attached to a horizontally installed single-shaft or multi-shaft kneading shaft 4b, as shown in the example of FIG. 1, and an extrusion molding section 7 of a type that extrudes the raw material 20 from an extrusion molding dam 7d by extrusion molding blades 7c (which may be screws) and molds it. In the example shown in FIG. 1, the extrusion molding unit 7 conveys the raw material to be mixed by an extrusion molding blade 7c inside a casing 7a, and this extrusion molding blade 7c is provided on a rotatable extrusion molding unit shaft 7b.

[0015] Next, the difference in structure between the kneading section 4 and the extrusion molding section 7, which is important in managing the level of the kneaded raw material, will be described. The kneading section 4 has a structure in which the top surface can be opened (open, grating, observation window, easily openable lid, etc.) except for the kneaded raw material compaction section 4e that compacts the kneaded raw material. Therefore, the kneading section 4 can easily observe the internal level of the kneaded raw material from the top surface of the device. On the other hand, the extrusion molding section 7 is surrounded by a strong liner on all sides except the vacuum chamber 6 in order to maintain the conditions of compaction and vacuum degassing of the kneaded raw material 20, and the inside of the device cannot be observed from the top surface of the device. Furthermore, even if a non-contact level meter (for example, a laser distance meter, a microwave level meter, etc.) is used to measure the level of the kneaded raw material in the extrusion molding section 7 from the observation window 10 at the top of the vacuum chamber 6, as described above, the level meter frequently picks up the height of the kneaded raw material 20 falling in the vacuum chamber 6, so the level of the kneaded raw material in the extrusion molding section 7 cannot be stably and continuously measured. Therefore, in measuring the raw material level in the extrusion molding section 7, a method for measuring from a limited measurement location (sight window 10) while avoiding erroneous detection due to the raw material 20 falling inside the vacuum chamber 6 is required.

[0016] Thus, it is necessary to use different methods for measuring the level of the raw material to be kneaded in the kneading section 4 and in the extrusion molding section 7.

[0017] The importance of early detection of an increase in the mixed raw material level in the extrusion molding section 7 is described below. In the extrusion molding section 7, the impact on operations when the mixed raw material filling rate exceeds the upper limit (mixed raw material filling rate > 95%) is much greater than the impact when it falls below the lower limit (mixed raw material filling rate < 50%). The reason for this is that when the mixed raw material filling rate falls below the lower limit and the vacuum degassing conditions are no longer met, there is no need to immediately suspend operations, and the mixed raw material filling rate in the extrusion molding section 7 can be easily increased by increasing the amount of mixed raw material supplied from the kneading section 4, and the vacuum degassing conditions can be restored.

[0018] Furthermore, if the raw material filling rate falls below the lower limit, the extrusion molding section 7d is no longer filled with the raw material 20, and the vacuum degassing conditions cannot be maintained. Therefore, if the vacuum degassing conditions are controlled with a pressure gauge, the decrease in the raw material filling rate can be easily and quickly detected. On the other hand, if the raw material filling rate exceeds the upper limit, there is a high concern that the device will stop due to overload or the vacuum chamber 6 or the extrusion molding section 7 will be damaged. In addition, if the device stops due to overload when the raw material filling rate exceeds the upper limit, it is necessary to suspend operation and take several hours to several tens of hours to carry out the discharge work of the raw material 20 and cleaning, which will be a major factor in reducing production. Furthermore, if the device is damaged, it may be necessary to suspend operation for a long period of time (for example, several tens of hours to several days) to repair it.

[0019] For these reasons, in controlling the level of the raw material being mixed in the extrusion molding section 7, a method capable of quickly detecting an increase in the level of the raw material being mixed is more important than a method for detecting a decrease in the level of the raw material being mixed.

[0020] The method of adjusting the level of the kneaded raw material in the extrusion molding section 7 is as described below. The level of the kneaded raw material in the extrusion molding section 7 can be adjusted by changing the rotation speed of the kneading shaft 4b to increase or decrease the supply speed of the kneaded raw material 20 from the kneading weir 4d. For example, when the rotation speed of the kneading shaft 4b is decreased, the supply speed of the kneaded raw material from the kneading weir 4d decreases, and the level of the kneaded raw material in the extrusion molding section 7 decreases. On the other hand, when the rotation speed of the kneading shaft 4b is increased, the supply speed of the kneaded raw material from the kneading weir 4d increases, and the level of the kneaded raw material rises. The level of the kneaded raw material can also be adjusted by changing the rotation speed of the extrusion molding shaft 7b to increase or decrease the discharge speed of the molded body from the extrusion molding weir 7d. For example, when the rotation speed is increased, the discharge speed increases and the level of the kneaded raw material decreases, and when the rotation speed is decreased, the discharge speed decreases and the level of the kneaded raw material increases. Furthermore, if the level of the mixed raw material rises suddenly, the level of the mixed raw material can be lowered relatively quickly (for example, within a few minutes to a few tens of minutes) by temporarily stopping the rotation of the mixing shaft 4b to stop the supply of the mixed raw material to the extrusion molding section 7, by relaxing the vacuum degassing conditions (for example, from ≦-40 kPaG to 0 kPaG) to improve the fluidity of the mixed raw material 20 in the extrusion molding section 7 and promote the discharge of the mixed raw material from the extrusion molding section 7, or by removing the extrusion molding weir 7d (extrusion resistor) to promote the discharge of the mixed raw material from the extrusion molding section 7. [Prior art documents] [Patent documents]

[0021] [Patent Document 1] Patent No. 5000402 [Patent Document 2] JP 2000-263540 A [Patent Document 3] Publication number 04-030016 Summary of the Invention [Problem to be solved by the invention]

[0022] The present invention is directed to a measurement method and device that can quickly determine an increase in the level of mixed raw materials in the extrusion molding section 7 of a vacuum extrusion molding apparatus, and provides a mixed raw material level measurement device and a mixed raw material level management method that use images to detect an increase in the mixed raw material level in the extrusion molding section at an early stage. [Means for solving the problem]

[0023] In order to solve the above problems, (1) A raw material mixing inlet, a connecting pipe that leads the raw material to the mixing section, a kneader equipped with a shaft equipped with a impeller, a weir through which the raw material is pushed out, a vacuum chamber, and an extrusion molding section are arranged in this order, and a sight glass is arranged at the top of the vacuum chamber, and a light arranged above the sight glass illuminates the raw material mixing in the lower part of the vacuum chamber through the sight glass, and an imaging device arranged above the sight glass takes an image of the raw material mixing level in the lower part of the vacuum chamber, thereby observing the rise in the raw material mixing level and measuring and managing the raw material mixing level in the vacuum chamber.

[0024] (2) At that time, it is preferable to place one or more rubber or resin plates hanging downward on the inner wall of the vacuum chamber, adjust the lower ends of the plates to a predetermined position where the level of the mixed raw material in the extrusion molding section is judged to be the upper limit, and confirm that the lower ends of the rubber or resin plates are pushed up and curved by the mixed raw material to judge whether the level of the mixed raw material in the extrusion molding section has exceeded the upper limit.

[0025] (3) It is also preferable that the sight glass is elevated above the upper end of the kneading section and / or a heater is disposed in the sight glass to raise the temperature, thereby preventing the kneaded raw material from adhering to the sight glass.

[0026] (4) Furthermore, the raw material level measurement and management device in the vacuum chamber is characterized in that a raw material inlet for mixing, a connecting pipe for leading the raw material to the mixing section, a mixer having a shaft equipped with an impeller, a weir through which the raw material is extruded, a vacuum chamber, and an extrusion molding section are arranged in that order, a sight glass is arranged at the top of the vacuum chamber, a light is arranged above the sight glass, and an imaging device is arranged above the sight glass.

[0027] (5) At that time, it is preferable that one or more rubber or resin plates are placed hanging down on the inner wall surface of the vacuum chamber, with their lower ends adjusted to a predetermined position where the level of the mixed raw material in the extrusion molding section is judged to be the upper limit, and that a monitor is provided to confirm that the lower ends of the rubber or resin plates are pushed up and curved by the mixed raw material, thereby judging whether the level of the mixed raw material in the extrusion molding section has exceeded the upper limit.

[0028] (6) It is also preferable that the observation window is elevated above the upper end of the kneading section and / or that a heater is disposed in the observation window. Effect of the Invention

[0029] According to the present invention, it has become possible for an operator to easily and frequently check the raw material level in the extrusion molding section 7 from the control room, a task that was previously performed periodically by an operator. [Brief description of the drawings]

[0030] [Figure 1] FIG. 1 is a diagram showing a kneading and molding machine consisting of a first extrusion section (kneading section) and a second extrusion section (extrusion molding section). [Diagram 2] FIG. 13 is a diagram showing an example of how a camera 11 is installed in a test using an actual device. [Diagram 3] 1 is a photograph of the extrusion molded portion 7 observed through a viewing window 10. [Figure 4] FIG. 1 is a schematic diagram of the present invention method. [Diagram 5] FIG. 11 is a photograph of the curved state of a rubber plate 13 taken on an actual device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] In the present invention, we have devised a method for easily and quickly detecting and managing increases in the level of mixed raw materials in the extrusion molding section 7 by monitoring the level of mixed raw materials in the extrusion molding section 7 frequently (for example, once every few to 10 minutes) from an operation room where an operator is present, rather than monitoring the level of mixed raw materials in the extrusion molding section 7 visually, which was previously done by an on-site worker (who is not always near the vacuum extrusion molding apparatus) going to the sight glass 10 periodically (for example, every hour).

[0032] First, we tested a method in which the image of the camera installed in the observation window 10 was simply transferred to a monitor in the operation room and monitored by an operator in the operation room. The camera installation method used in this test is shown in Figure 2. An example of the structure near the kneading section 4 of this technology is as shown in Figure 2, and 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 provided on the shaft 4b. The 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 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. An observation window 10 is provided at the top of the vacuum chamber 6 .

[0033] Here, lighting 12 (light, etc.) and camera 11 are required to capture the image, but there is no particular limit to the type as long as they provide an appropriate amount of light (enough to ensure that the bottom of the extrusion molded portion 7 is clearly visible; a normal LED light, etc., will do) and a pixel count (approximate to that of a normal commercially available video camera). It is preferable to use a camera that is suitable for shooting in dark places, such as an infrared camera. Furthermore, lighting 12 can be installed anywhere above viewing window 10 as long as it can illuminate the shooting position of camera 11.

[0034] With this method, the operator can easily check the monitor from his / her desk, so the monitoring frequency increases (about once every few to tens of minutes). However, as described below, it is not easy to determine whether the mixed raw material level has risen, so there is a possibility that the operator watching the image on the monitor may not notice the rise in the mixed raw material level, or the judgment may vary from operator to operator. Therefore, we decided to consider a means to easily determine whether the mixed raw material level has risen.

[0035] As a result, we have devised a method for determining whether the raw material level in the extrusion molding section 7 has risen, by visual inspection, so that the operator can determine at a glance whether the raw material level in the extrusion molding section 7 has risen. The details of this method are described below.

[0036] 1) Difficulty in judging whether the mixed raw material level has risen (disturbance of judgment) Disturbances that make it difficult to judge whether the level of the mixed raw material in the extrusion molding section 7 has risen will be described. When observing the level of the mixed raw material in the extrusion molding section 7 through the observation window 10, the mixed raw material 20 supplied from the kneading weir 4d always falls inside the vacuum chamber 6, so the lower extrusion molding section 7 can only be seen intermittently. Furthermore, generally, the only criterion for judging whether the level of the mixed raw material has risen is when the extrusion molding shaft 7b or the extrusion molding blade 7c, which can be seen intermittently, cannot be seen for a while (for example, a dozen or so seconds to several tens of seconds). This is because even if a marker is placed inside the extrusion molding section 7 or the vacuum chamber 6 using a color or protrusions, the mixed raw material 20 will adhere to the marker during long-term operation (for example, a dozen or so hours to one day), making the marker invisible (the marker can be seen visually on a trial basis (for example, several tens of minutes to several hours), but not during normal operation). On the other hand, since the extrusion molding shaft 7b and the extrusion molding blades 7c are constantly moving, there is little adhesion of the raw material 20 to be kneaded, and when light is shone on them, they reflect light, so this can be confirmed visually.

[0037] FIG. 3 shows a photograph of the extrusion molding section 7 observed through the observation window 10. FIG. 3, 1) is a photograph before the raw material 20 is fed into the extrusion molding section 7, and shows the internal mechanism. FIG. 3, 2) and 3) are photographs of the state in which the machine is operating normally (raw material filling rate of 95% or less). From FIG. 3, it can be seen that even if the raw material level is normal, the extrusion molding blades 7c and extrusion molding shaft 7b can only be seen intermittently due to the raw material 20 falling inside the vacuum chamber 6 and the raw material 20 being transported inside the extrusion molding section 7 towards the exit side.

[0038] Therefore, currently, an on-site worker adheres to the observation window 10 about once every hour to several hours and observes the extrusion molding section 7 continuously for several tens of seconds to several minutes to determine whether the mixed raw material level is normal (the extrusion molding blade 7c and the extrusion molding shaft 7b are visible) or abnormal (the extrusion molding blade 7c and the extrusion molding shaft 7b are not visible). However, if an operator in the operation room tries to perform this monitoring method (which takes several tens of seconds to several minutes to determine normality / abnormality once) frequently (for example, once every several minutes to several tens of minutes), the proportion of time the operator spends looking at the monitor to determine normality / abnormality becomes too large, which interferes with other work. Therefore, in order to monitor the mixed raw material level frequently by visual inspection of the image, it is necessary to shorten the time required for normality / abnormality determination.

[0039] 2) Setting the criteria for determining the mixed raw material level In the present invention, in order to shorten the time required to judge the level of the raw material to be kneaded (currently several tens of seconds to several minutes), we have devised a method of using a rubber plate or the like (natural rubber, synthetic rubber, thin resin, etc., as long as it is easily bent under load) hung on the inner wall surface of the vacuum chamber 6. Figure 4 shows an outline of the invented method.

[0040] In Fig. 4, rubber plates 13 are installed on both ends of vacuum chamber 6 (at least on the side where the camera is installed), and their bottom ends are adjusted to be at the upper limit of the raw material level (the position where the raw material filling rate in extrusion molding section 7 is 95%). This rubber plate 13 is fixed only at the top of vacuum chamber 6, and its bottom end is free. Therefore, when the raw material level is below the upper limit (normal), it hangs down vertically as shown in Fig. 4 1).

[0041] On the other hand, when the level of the raw material to be kneaded exceeds the upper limit (abnormality), the lower end of the rubber plate 13 is pushed up from below by the raw material to be kneaded 20 and curved toward the center of the vacuum chamber 6, as shown in Fig. 4 2). Since this rubber plate 13 is always visible during operation, it is not necessary to keep looking inside the vacuum chamber 6 for a long period of time (tens of seconds to several minutes) to check the curved state of the rubber plate 13. Furthermore, such a rubber plate is generally expected to have the effect of reducing adhesion of the raw material to the wall surface of the vacuum chamber 6.

[0042] Figure 5 shows the curved state of rubber sheet 13 photographed on an actual machine. From Figure 5, it can be seen that it is easy to visually determine whether rubber sheet 13 is hanging vertically downward (normal) or curved (abnormal). As a result of the investigation, an operator in the control room can easily (no variability in judgment) and quickly (visual check of the monitor within a few seconds) determine whether the level of the mixed raw material in extrusion molding section 7 has exceeded the upper limit by remotely checking the video captured by camera 11 on a monitor in the control room.

[0043] 3) Suppression of adhesion of the observation window 10 In order to continue stable judgment based on the image for a long period of time, it is preferable to take measures against adhesion of the raw material to be mixed to the observation window 10. For example, measures can be taken to raise the observation window 10 to prevent dust scattered from the gate 4d from reaching the observation window 10, or to heat the observation window 10 to prevent condensation from occurring. The height of the raising should be approximately 10 cm or more, and preferably approximately 20 cm or more.

[0044] On the other hand, if the elevation is too high, it may interfere with other equipment when opening and closing the peephole 10 for internal cleaning, etc., or the manufacturing cost may increase, so the elevation height is preferably up to about 30 cm. There is also a concern that the peephole 10 may become cloudy due to condensation. If the temperature of the peephole 10 is raised to about 40°C or higher, condensation can be suppressed, but if the temperature of the peephole 10 is too high, there is a concern that peripheral equipment such as a level gauge may be damaged by heat, so it is preferable to raise and control the temperature to a range of about 40 to 90°C. Here, the temperature of the peephole 10 can be raised by simply placing a general heater (such as a glass heater) around the peephole 10, and this can be done without blocking the camera's field of view.

[0045] 4) How to adjust the mixed raw material level If the image of the raw material level can be frequently checked by the above means, the raw material level can be adjusted by the above-mentioned raw material level adjustment method and kept stable. [Explanation of symbols]

[0046] 1 Mixer 2 Inlet 3 Connecting Pipe 4. Mixing section 4a Casing 4b Kneading shaft 4c Mixing blade 4d Mixing Weir 4e. Raw material consolidation section (where the raw material is consolidated before the weir and where mixing is particularly prominent) 4f Internal observation area on top of the mixer (grating, glass window, opening, etc.) 5 Water nozzle 6 Vacuum chamber 7 Extrusion Molding Section 7a Casing 7b Extrusion shaft 7c Extrusion molded blade 7d Extrusion weir 8. Vacuum Pump 9 Vacuum pump connection pipe 10. Peephole 11 Camera 12. Lighting 13 Rubber plates (natural rubber, synthetic rubber, and thin resin that easily bend under load) 20 Mixing materials

Claims

1. A raw material inlet, a connecting pipe for introducing the raw material to the kneading section, a kneader having a shaft equipped with an impeller, a gate through which the raw material is extruded, a vacuum chamber, and an extrusion molding section are arranged in this order, and a viewing window is arranged at the top of the vacuum chamber, One or more rubber or resin plates are arranged on the inner wall surface of the vacuum chamber so as to hang downward, and the lower end of each plate is adjusted to a predetermined position where the level of the kneaded raw material in the extrusion molding section is determined to be the upper limit; A light arranged above the sight glass is used to illuminate the raw material at the lower part of the vacuum chamber through the sight glass, and an image of the raw material level at the lower part of the vacuum chamber is taken by an image pickup device arranged above the sight glass, thereby observing the rise in the raw material level; This method for measuring and managing the level of mixed raw material in a vacuum chamber is characterized by confirming that the lower end of the rubber or resin plate is pushed up and curved by the mixed raw material, and determining whether the level of the mixed raw material in the extrusion molding section exceeds an upper limit.

2. The method for measuring and managing the level of mixed raw materials in a vacuum chamber as described in claim 1, characterized in that the sight glass is elevated above the upper end of the kneading section and / or a heater is placed in the sight glass to raise the temperature, thereby preventing the mixed raw materials from adhering to the sight glass.

3. The mixing raw material inlet, the connecting pipe that introduces the raw material to the mixing section, the mixer with the shaft equipped with the impeller, the weir through which the raw material is extruded, the vacuum chamber, and the extrusion molding section are arranged in this order. One or more rubber or resin plates are arranged on the inner wall surface of the vacuum chamber so as to hang down, and the lower end of each plate is adjusted to a predetermined position where the level of the kneaded raw material in the extrusion molding section is determined to be the upper limit, a peephole is disposed in an upper portion of the vacuum chamber, a light is disposed on the peephole, and an imaging device is disposed on the peephole; A raw material level measuring and management device in a vacuum chamber, characterized in that it is equipped with a monitor used to confirm that the lower end of the rubber or resin plate has been pushed up and curved by the raw material and to determine whether the raw material level in the extrusion molding section has exceeded an upper limit.

4. 4. The device for measuring and managing the level of raw materials being mixed in a vacuum chamber according to claim 3, wherein the sight glass is elevated above the upper end of the kneading section and / or a heater is provided in the sight glass.

Images