JPS6233621A - Extruder - Google Patents

Abstract

PURPOSE:To prevent extrusion inferiority and to attain to facilitate the cleaning work of a screw and a barrel, by providing not only a discharge passage for discharging a part of a material to the outside of the high-pressure regions of a die and a barrel generated by combining screws but also a discharge passage sending a part of the material to the low-pressure region in the downstream side. CONSTITUTION:The temp. of a food material in an auxiliary barrel 41 comes to abnormally high temp. and this temp. is detected by an auxiliary temp. sensor 44C. If operation is allowed to continue in this state, scorching is generated. In order to prevent this phenomenon, a part of the food material is discharged to the outside from a discharge passage 42C and the pressure of said passage is lowered to restore normal operation. Further, a part of the food material is divided from the boundary part of a righthand screw 15A with a lifthand screw 15B to be made to flow to a discharge passage 42 and met with the part of the righthand screw 15c in the downstream side through a valve device 43 (a bypass is formed) to discharge the food material to the discharge passage 42 only from the part of a nozzle 21. At this time, the valve apparatus 43 provided to a die 21 is opened to make is possible to discharge the residual material to the outside long with water from the discharge passage 42.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an extruder, mainly a twin-screw extruder, in which material can be easily discharged from the middle of the barrel and nozzle.

Although the present invention can be applied to plastic, rubber, food extruders, etc., this specification will be explained using an example of a two-screw food extruder, which has become frequently used in recent years.

2. Description of the Related Art An example of a conventional food extruder will be explained with reference to FIG. The food extruder I1 has a plurality of pressure-resistant barrels 13A, 13B...+3Ni on the base, which are connected horizontally so that their hole cores are aligned, integrally forming one barrel, and mounted on the frame 12. It is supported by attached columns. Inside this barrel, a rotating screw shaft 14 whose one end is connected to a drive source (not shown) is inserted over almost the entire length of the barrel.
A plurality of screws 15 for the purpose of transporting foodstuffs, mixing lines, etc. are fitted onto the outer periphery of this soup stock 1)-shaft 14 in an order that matches the molding conditions. At the top of the barrel 13A, a theta 16 for receiving food (not shown) opens upward, and a fixed amount of food is supplied from a feeder 17 provided at the top of the theta 16.

Heat exchangers 18B, 1 for heating or cooling these barrels are provided on the outer peripheries of the barrels 13B, 13c...13N.
8c...18N are installed respectively. Also,
Temperature sensor 19B, 1 for detecting the temperature of each barrel
9c...I 9N are inserted toward the center of the hole in each barrel, and the tip, which is the detection part, is located close to the inner wall of the barrel. The barrels 13B, 13c...13
N is automatically controlled to a set temperature by an automatic temperature controller (not shown).

A die 2 having an orifice 20 is provided on the end face of the barrel 13N.
1 is fixed, and the die 21 is also attached to the barrel 1 (not shown).
3B, +3c...The temperature is controlled in the same way as 13N. Barrel l 3 AK An open hole 22 for water injection is provided, and a water storage tank 32 of a water injection device 31 is provided at the top, and an on-off valve 33, a metering pump 34, and a check valve 35 are connected in series from the bottom of this tank 32. They are each connected by a pipe 36, and the tip of the pipe is connected to the hole 22 of the barrel 13A.

Next, to describe the operation, the screw shaft 14i is driven,
Rotate the screw 15 to feed theta 1 from the feeder 17.
While feeding the food into the barrel 13A, the on-off valve 33 of the water injection device is opened and the metering pump 34 is operated to continuously inject a fixed amount of water into the hole 22 of the pressurized water barrel t+3A. On the other hand, the food introduced into the barrel 13A is heated, pressurized, crushed, and kneaded while being transferred by the rotation of the barrels 13B, 13c, . It is extruded and molded from the orifice 20 of.

The screws used in food extruders have various shapes, such as right-handed screws, left-handed screws, right-handed kneading disks, and left-handed kneading disks. A left-handed screw or a left-handed kneading disk has the function of transferring ingredients in the opposite direction. For example, if a left-handed screw is installed next to the downstream side of a right-handed screw in the configuration of Sufu IJ" + 5, the right-handed screw The flow of ingredients transported by the screw is dammed at the boundary.In other words, it has the effect of a dam, and high pressure is created at this boundary to dam the continuously fed ingredients.

As the food is transported inside the barrel by the screw, its temperature increases due to heating, pressurization, crushing, kneading, and friction and shearing with the inner wall of the barrel and the outer circumferential surface of the screw, and the temperature can reach over 200°C depending on the pressure conditions. There is also.

Efficient processing can be achieved by filling this boundary and the area around it with food and heating or cooling it.

Regarding the kneading disk, the effect of the kneading action can be changed by shifting the phase or changing the thickness by using multiple stages.
Alternatively, it is also possible to incorporate a left-handed kneading disk to provide the same effect as a left-handed screw for transferring food in the opposite direction. In this way, by combining a right-handed screw with a left-handed screw, by combining left and right kneading disks, or by other combinations, you can adjust the temperature of the barrel, the rotation speed of the screw, and the amount of food supplied. Efficient extrusion processing is performed while controlling the retention time, pressure, and temperature of the ingredients inside the barrel by setting the amount of water added and other conditions to the optimum conditions.

Problems to be Solved by the Invention As mentioned above, the temperature control for the barrels 13A, 13B, .

The temperature is automatically controlled to a set temperature by an automatic temperature controller (not shown) combined with 19c...19N. The temperature of the die 21 is also controlled in the same way as the barrel. However, the temperature sensor I'9B,1
The temperature detected at 9C...19N is different from the temperature of the food actually processed, and there are problems as described below. That is, the food inside the barrels 13B, 13c... 13N generates heat due to friction and shear between the screen 15 and the inner walls of the barrels 13B, 13c... 13N. This heat generation varies depending on the composition of the food material, unevenness in the amount supplied to the barrel 13, the amount of moisture in the food material itself, the amount of water poured, the number of screw rotations, etc. Even if the temperature of the food becomes abnormally high, the temperature is immediately raised to barrel 13B.

13c...13N, and as a result, the food material: - Leverage occurs and the food material is not transferred. Eventually, it becomes impossible to extrude the food material from the die 21, and the screw 15 becomes unable to rotate, causing the barrel 13A. .

13B...+3N removal 9 of the screw 15 and the screw 15 and barrel 13A after removal.

It became difficult to remove and clean the burnt food inside 13B...13N, and it took a lot of time and money to restart the operation, resulting in a huge economic loss. In particular, this problem of burning tends to occur at the boundary between the right-handed screw and the left-handed screw, at the high-pressure area where the kneading disk, etc. are combined, or at the die 21 section.

Further, there are also problems as described below when the operation is stopped.

When the operation is stopped, the set temperatures of the barrels 13B, +3C...13N and the die 21 are lowered, the amount of water added is increased, and the screw rotation speed and the amount of food supplied are gradually decreased.
After confirming that the temperature of the food material extruded from the orifice 20 and the temperature of the barrels 13B, +3c, . Next, stop the rotation of the screw and stop adding water. After confirming that the food material is no longer discharged from the orifice 20, completely remove the die 21 from the barrel 13N, and screw the screw from inside the barrel 13A, 13B...13N. 15, screw 15 and barrel 13A, 13
B: Removal of food adhering to the inside of 13N and cleaning.

However, foodstuffs aggregate in the boundary between the right-handed screw and the left-handed screw of screw j5, the high-pressure area that combines the kneading disk, etc., that is, the area that causes the action of a weir, and acts as a plug that inhibits the transfer of ingredients. It was difficult to completely extrude and remove the food materials in the barrels 13A, 13B, . . . , 13N from the orifice 20. Therefore, the Sufu I73-1 was left with food partially remaining inside the barrel.
5 has to be extracted, and a great force is required, and a special jig or device is required for the extraction work.
3B... 13N had drawbacks such as removal of food materials adhering to the screw 15 and cleaning work were troublesome.

The present invention has been developed in view of the above-mentioned points, and it is possible to prevent defective extrusion due to burning of food materials in the high temperature and high pressure parts during operation of the extruder, to facilitate the removal of the screw when the operation is stopped, and to make it easier to remove the screw from the barrel. The purpose is to facilitate the cleaning of the screw and barrel, and to enable stable extrusion molding.

Elaborate means to solve the problem The present invention rotates a screw in a barrel with a die having an orifice attached to the tip, heats, pressurizes, crushes, cross-wires, etc. while transferring the material, and extrudes it from the die. In an extruder for obtaining a product, a tth discharge path for discharging a part of the material to the outside into a high-pressure area of a die and barrel generated by a combination of screws, or sending a part of the material to a downstream low-pressure area. In addition to providing a bypass exhaust passage that allows for a discharge passage, the exhaust passage is provided with a valve device for opening and closing the exhaust passage, and abnormally high temperature or abnormally high pressure is detected by a temperature sensor or pressure sensor provided in the high pressure area.

In this extruder, the valve device is temporarily opened in response to the signal, and a part of the material is discharged from the discharge path to the outside or sent to the downstream side.

Temperature sensor installed in the high pressure area of the working nozzle or barrel
A pressure sensor detects abnormally high temperature or abnormally high pressure, and in response to that signal, a device installed in the discharge path is temporarily opened to discharge part of the material under the high pressure area to the outside, or to drain the material under the low pressure downstream. Send to area.

Embodiment An embodiment of the present invention will be explained with reference to FIGS. 1 to 5, which show an embodiment of the present invention. Barrel 13A in FIG.

13B'...13N1 Scrier shaft 14, screw 15
, theta 16, feeder 17, heat exchanger 18B.

18c...18N, temperature sensor 1 (7B, 19C...
・19N1 orifice 20, die 21, hole 22° water injection device 31. Tank 32, on/off valve 33% measuring pong 34
, the check valve 35 and the piping 36 are the same members as those in the conventional embodiment shown in FIG. 6, so a detailed explanation will be omitted and only the different parts will be explained.

Between barrel L/bar 13c and barrel 13D 1c auxiliary) (v
An auxiliary barrel AIN is provided between the die 210 and the barrel 41C and the barrel 13N, and these auxiliary barrels 41 and A
IN has discharge passages 42C and 62N, respectively.

Valve device 1!13c, 43N and auxiliary temperature sensor 4AC
.

44N is provided. The auxiliary temperature sensor 44C1
The temperature detection part at the tip of 44N is the auxiliary barrel 41C141N.
The auxiliary temperature sensor Arc is inserted into the hole to directly detect the temperature of the food, and the auxiliary temperature sensor AILN is connected to the valve device 43C via the A timer 45N, and the auxiliary temperature sensor AILN is connected to the B timer 45N. Valve devices 43C and A3N, which are normally closed, are opened for a certain period of time in response to signals from auxiliary temperature controllers 44C and 44N, which are connected to valve device 43N.

Next, the operation of the embodiment described above will be explained. During normal extrusion, the food material is heated, pressurized, crushed, mixed, etc. inside each barrel (including the auxiliary barrel) while being transferred by the rotation of the screw 15 without becoming particularly high pressure or high temperature.
It is extruded from the orifice 20 of the die 21. In this case, the auxiliary temperature sensors 44C and 44N do not operate because the food temperature is normal. Here, for example, the temperature of the food in the auxiliary barrel AIC becomes abnormally high, and this temperature is detected by the auxiliary temperature sensor 44.
When C is detected, this output signal causes A timer 45C'
i Operated valve device/13ci fixed time opening auxiliary barrel 4
A part of the food inside 1C is discharged to the outside from discharge path A2C. If you continue to operate without discharging the food to the outside, the food will aggregate in the high temperature and high pressure area and will not be transported, eventually causing burnt food. In order to prevent this, some of the food in this area is discharged to the outside, thereby reducing the pressure in this area to the normal level and restoring normal operation. The same operation is performed for the auxiliary barrel 41N section. The amount of food supplied when this abnormally high temperature is detected and some of the food is discharged outside.

If the amount of water added, the number of rotations of the screw, etc. are adjusted in conjunction with each other, more preferable operation control becomes possible.

FIG. 2 shows another embodiment of the auxiliary barrel 41C shown in FIG.
The timer 45C'i is not provided, and a discharge passage 42 and a valve device 43 are provided to manually discharge a portion of the food to the outside. In this case, the food discharge operation is performed by die 2 during operation.
When extrusion from the orifice 20 of No. 1 is stopped, a valve device 43 is arbitrarily opened to discharge the abnormally high-temperature food to the outside without staying in the auxiliary barrel 41 and return to normal operation. This mechanism can also be applied to the auxiliary barrel 41N portion shown in FIG. Further, this valve device 43 may be configured such that a screw plug is provided in a part of the discharge passage 42 to open and close the plug.

FIG. 3 shows yet another embodiment in which the discharge passage 42 is not provided in the auxiliary barrel 41C or 41 as shown in the embodiments shown in FIGS. 1 and 2, but is provided in the barrel 13 (collectively referred to as 13A to 13N). It is. In this way, the discharge passage 42 can be provided in any barrel as required.

Furthermore, as shown in FIG. 4, the orifice 20 of the die 21
It is also possible to provide a discharge passage 42 near the extrusion molding machine and use it as a bypass, for example, to discharge defective extruded products from the discharge passage 42 via the valve device 43 without sending them to the subsequent stage of the extrusion molding machine.

As mentioned above, the discharge passage 42 is located, for example, at the boundary between the right-handed screw +5A and the left-handed screw IJ-15B of the T-screw 15 shown in FIGS. 2 and 3, or at the die 21 shown in FIG.
By installing it in the high pressure area of the section, the kneading disk section, or the entire downstream side of the right-handed screw with a different pitch (small pitch), you can easily create a barrel! 3 Food can be discharged from inside to outside. Generally, the discharge passage 42 of the barrel 13 is fixed and cannot be changed freely, so the combination of the screws 15 is taken into consideration.

Figure 5 shows right-handed screw 15A and left-handed screw 15B.
This is still another embodiment in which a part of the food material is diverted to the discharge path 42 from the boundary part with the valve device 43 and merged into the downstream right-handed threaded screw +5c section (forming a bypass). In this case, for example, in the case of FIG. 1, only the discharge passage 42
There is no need to provide any other outlet 42 as long as the food is discharged.

Next, the operation when the operation is stopped will be explained. This operation is almost the same as the conventional one, and first, the barrel 13B.

13c...The set temperature of 13N and die 21 is lowered, the amount of water added is increased, the screw rotation speed and the amount of food supplied are gradually decreased, and die 2! The temperature of the food material extruded from the orifice 20 and the barrel 13B.

After confirming that the temperature of +3c...13N has fallen sufficiently, the operation of the feeder 17 is stopped, and the supply of food materials is stopped. In this state, while continuing to add water, the screw 15 is rotated to transfer the remaining foodstuffs in the barrels 13A to 13N to the downstream side. However, as shown in Figures 2 and 3, the weir is located at the boundary between the right-handed screw 15A and the left-handed screw 'J-15B, and in areas where high pressure is generated due to the combination of kneading disks and other screws (not shown). The food material aggregates in the lever portion throughout the action and acts as a plug, and the food material is not transferred to the downstream side of this portion and is no longer discharged from the orifice 20 of the die 21. Then, the valve device 43 is opened to discharge some of the aggregated food to the outside from the entire discharge passage 42, or a bypass is utilized in the downstream right-handed screw portion to release the feed valve.

Thereafter, the remaining food material is transferred to the die 2I side. At this time, as shown in FIG. 4, the remaining material along with water can be discharged to the outside through the discharge passage 42 by opening the friendly device 43 installed in the die 21.

In this way, the ingredients inside the barrels 13B, 130...13N and the die 21 can be completely discharged, and the added water can be used to remove the ingredients from the barrels 13B, 13c...
- The self-cleaning function of the screws 15 that engages with each other removes food adhering to the inner walls of the 13N and the screws 15, and the food is completely washed with water. Therefore, when removing the screw 15 from the barrels 13A, 13B...13N, the die 21 is removed from the barrel 13N and then the screw shaft 14 and the barrels 13A, 13B...1 are removed.
The drawer can be easily pulled out by hand from inside the 3N.

The present invention is particularly effective in the case of a twin-screw extruder, but it can also be applied to a single-screw extruder and to three or more screw extruders. ′! ! : In the embodiment shown in FIG. 1, auxiliary temperature sensors 4AC and 44N are used, and valve devices 43C and 4
Although the auxiliary temperature sensors 44C and 44N are opened and closed, pressure sensors may be substituted. In addition, a cooling vent or the like is provided in a part of the discharge passages 42.42C and 112N to circulate cooling water. 4
2C.

It is desirable and more effective to prevent the foodstuffs staying in the 42N from being stirred up during grilling.

Effects of the invention When material accumulates in the high-pressure area of the nozzle or barrel and receives strong shear from the screw and inner wall of the barrel, it becomes abnormally high temperature, part of the material is discharged from the high-pressure area before it burns to the outside. Alternatively, by providing a bypass discharge path in the downstream low-pressure region and sending the product, the pressure immediately returned to normal, and extrusion molding could then be carried out at stable pressure and temperature. Furthermore, after the operation is stopped, most of the remaining food inside the barrel can be discharged to the outside, and the screw can now be easily removed from the inside of the barrel without the need for great force or tools. As a result, food materials do not adhere to and remain on the screw and barrel wall surfaces, making the cleaning work easier and the work after molding can be completed in a shorter time, which has remarkable effects.

[Brief explanation of drawings]

1 to 5 are drawings showing embodiments of the present invention, in which FIG. 1 is a cross-sectional view showing the entire length of the barrel portion, FIGS. 2 to 5 are cross-sectional views showing main parts of the present invention, and FIG. The figure is a partially sectional side view of a conventional extruder. 13.13A~13N... Barrel, 15... Screw, 16... Shooter (supply port), 17... Feeder, 48B, +8c~IgN...
・Heat exchanger, 19B, 190~l'7N...Temperature sensor, 20...Orifice, 21...Die,
31...Water injection device% 42.42C, 42N...
Exhaust channel. 43, 43C, 43N... Valve device, A5C, 45N... Timer.

Claims (5)

[Claims] (1) A screw is rotatably inserted into a barrel that has a raw material supply port at one end and a die with an orifice at the other end and a heat exchanger on the outer periphery, and the material is supplied from the supply port by rotation of the screw. In an extruder, a part of the material is heated, pressurized, pulverized, kneaded, etc. while being transferred to obtain an extruded product from the orifice of the die. A discharge passage for discharging the material or a discharge passage capable of sending a part of the material to a downstream low pressure region is provided in a bypass manner,
An extruder characterized in that the discharge passage is provided with a valve device for opening and closing the discharge passage. (2) The extruder according to claim 1, wherein the valve device is opened and closed by a signal from a temperature sensor or a pressure sensor provided in a high pressure region of the barrel and die. (3) The extruder according to claim 1, wherein the valve device is opened and closed manually. (4) The extruder according to claim 1, 2, or 3, wherein the high pressure region is a boundary between a right-handed screw and a left-handed screw. (5) The extruder according to claim 1, 2 or 3, wherein the high pressure region is a boundary between a right-handed screw and a kneading disk, particularly a left-handed kneading disk.