JP2008011838A - Heat-treating apparatus of granular substance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive heat-treating apparatus using a powdery or granular substance as a raw material to be treated, and accurately heat-treating the substance in a short time. <P>SOLUTION: This inexpensive heat-treating apparatus with high energy efficiency is such that an extruder of a powdery or granular substance is composed of a barrel assuming pressurizing/shearing a raw material, and an exit nozzle assuming adjustment of flow rate and pressure, wings are attached each to the screw outer surface and cylinder inner surface of the barrel so as to shear an extruded raw material between the wings, and the exit nozzle has a structure of arranging a structure which gives resistance to flow of a raw material to be extruded so as to heat the raw material with shearing heat. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a heat treatment apparatus for heating powder or granular grain raw materials for a short time.

In general, there has been no suitable short-time heating control device that uniformly and accurately heats powdered or granular substances such as rice bran and soybean at 130 degrees Celsius (hereinafter abbreviated as 130 ° C.) for 5 seconds. An extruder is suitable as a heating device because heat is generated by the raw material itself by friction and shear in the process of extruding the raw material. For example, FIG. 1 of Patent Documents 1 and 3 and FIG. 3 of Patent Document 2 show examples. However, since friction and shear are concentrated on the cylinder tube surface of the extruder, temperature unevenness occurs in the raw material, and the intended heat treatment cannot be made uniform.
U.S. Pat. S. 4,741,264 (Fig. 1) Patent Bulletin No. 2956622 (page 3 Fig. 3) Patent Publication 2004-209132 (Fig. 1)

When sterilizing powder, granular grains, spices, etc., the heat treatment conditions for sterilization without losing the flavor and nutrients require short time and accurate control, for example, heating at 150 ° C. for 5 seconds. As an ultra-high temperature (UHT) powder sterilization method for such purpose, there are a superheated steam method and a biaxial extruder method, but the disadvantage is that the apparatus cost and the operation cost are high. The present invention is to achieve UHT sterilization and enzyme deactivation with a uniaxial extruder, greatly reducing sterilization cost and energy consumption.

Since the extruder can use the heat generated by the friction and shear of the raw material itself during the process of extruding the raw material, the structure is simple, energy efficient, and suitable as a low-cost heating device. However, in the case of an extruder, since the raw material becomes a compacted mass in the barrel, the product temperature rises due to friction and shear heat at the part in contact with the cylinder tube surface. If the rate is low, the product temperature will vary significantly. For this reason, heat processing becomes non-uniform | heterogenous and lipase inactivation and disinfection become inadequate. Rice bran has a very poor thermal conductivity, so according to experiments, the product temperature unevenness is as large as 50 ° C to 80 ° C. The present invention provides a heat treatment apparatus that eliminates uneven product temperature and is low in cost and energy efficient by disposing a resistor at the outlet nozzle so that the raw material in the barrel is pressurized and sheared near the center of the passage. It is something to be offered.

The present invention comprises a powder or granular raw material extruder composed of a barrel responsible for pressurization and shearing of the raw material and an outlet nozzle responsible for flow rate and pressure regulation, and blades are extruded onto the screw outer surface and cylinder inner surface of the barrel. The heat treatment apparatus is characterized in that the raw material to be sheared between these blades and the outlet nozzle has a structure in which a structure that provides resistance to the flow of the extruded raw material is arranged to heat the raw material with shear heat It is related to.

According to the present invention, the following effects can be obtained. The raw material is extruded in the direction of the outlet by the screw blades between the screw and the cylinder, but is sheared between these blades because of the blades on the inner surface of the cylinder. If the outlet discharge resistance of the raw material is increased, the raw material is pressed by the pushing force of the cylinder to become a lump and generate large shear heat. If the passage gap is 5 mm and the height of both blades is 2.4 mm, the raw material is sheared at the center of the passage instead of the pipe surface. Here, the shear heat spreads in all directions from the center, so the product temperature unevenness is reduced. Further, if the gap between the outlet nozzles is narrowed to 1 mm or less and the raw material is sheared, the product temperature variation is further reduced. In addition, the height of the blades is increased near the inlet of the raw material to fill the barrel gap to ensure the extrusion force, and the outlet is changed from about 1/2 or from 1/3 to about 2/3. If the material is sheared at different positions in the passage, the raw materials are agitated during the extrusion process, and the product temperature uniformity is further increased. Here, a structure that can change the discharge resistance of the raw material can be installed on the outlet side to adjust the generation of shear heat according to the purpose.

The best mode for carrying out the present invention is one in which the extruder shown in FIG. 1 is equipped with the outlet nozzle with a crushing mechanism shown in FIG. Hereinafter, the case where the raw material is rice bran will be described, but the present invention is not limited to this, and can be applied to rice, wheat, beans, buckwheat, corn, and their powders, bran (rice cake), embryos and the like. In addition to grains, it can also be applied to tea leaves, spices, vegetables, fruits, mushrooms, mushroom culture media, plants, meat, seafood, pet foods and feeds that have been processed into powder or granules. The purpose of heat treatment of rice bran is to inactivate endogenous lipase and disinfect microorganisms contained in rice bran. Since an extruder for such a purpose is often called a stabilizer after its use, FIG. 1 is an overall view of the stabilizer.

Next, the operation of the illustrated example will be described. The raw material is injected into the hopper 3 and through the feeder 2 into the extruder barrel. The main part of the extruder includes a barrel part, an outlet nozzle part, and a main motor 1. The barrel portion is composed of a cylinder 15 and a screw 16 with blades, and a gap sandwiched between the two serves as a raw material passage 5, and heats the raw material by extrusion pressure, friction, and shear. The outlet nozzle part is composed of an inner ring 9 and an outer ring 10, and a resistor shown in FIGS. 3, 4, 5 and 6 is installed at the outlet part to adjust the flow rate and pressure of the raw material passing through the barrel. The screw 16 and the outlet inner ring 9 are mechanically coupled, and are driven and rotated by the main motor 1.

The raw material passes through a passage formed by a gap sandwiched between the cylinder 15 and the screw 16 and is pushed out by the screw blade 17 toward the outlet. Here, the height of the blade on the inlet side from the screw blade 17 is made substantially equal to the passage gap to ensure a sufficient pushing force. From the screw blade 19 onward, the blade height is lowered, and at the same time, the cylinder blade 18 indicated by a broken line is attached to the inner surface of the cylinder. Here, if the passage gap is H, the height of the screw blade is H1, and the height of the cylinder blade is H2, each blade is machined so that H = H1 + H2 + α. Α is a clearance for preventing the upper and lower blades from contacting each other, and is usually 0.1 to 0.3 mm.

The height of the blade is, for example, H1 = H−α near the entrance and H1 = (H−α) / 2 in the vicinity of the entrance in the direction of the raw material (screw axial direction). The angles of the cylinder blade and the screw blade intersect each other, and the angle (or pitch) of the cylinder blade is slightly smaller than the angle (or pitch) of the screw blade. In FIG. 1, for the sake of simplicity, both angles are the same.

When a raw material is extruded using the barrel as described above, the raw material is sheared when passing through a portion sandwiched between two blades and generates heat by itself. Since the place where heat is generated is almost in the center of the passage, heat is conducted from the center to all directions, and the temperature difference in the passage becomes small. In a normal extruder barrel, the cylinder is hollow and the inner surface is not provided with blades. Therefore, friction and shear are intensively generated on the cylinder tube surface, and heat is released from the cylinder iron tube to the outside. For this reason, the cylinder tube surface of the passage becomes hot, but heat is not transmitted to the inside, and remarkable temperature unevenness occurs in the raw material passing therethrough. According to the rice bran experiment, when the cylinder tube surface is 150 ° C., the screw surface is 80 ° C., and a temperature difference of 70 ° C. occurs.

The temperature of the raw material rises rapidly near the outlet of the barrel. If the outlet of the outlet nozzle is completely closed (the outlet resistance is infinite), the raw material is pushed back without being discharged, heated at a high temperature by repeated friction and shear in the barrel, and burnt. When the outlet resistance of the outlet nozzle is reduced, the raw material is discharged to the outside. The amount of heat generated in the barrel at this time is the power of the main motor 1, the structure, shape, material and raw material properties of the cylinder and screw (Poisson's ratio, specific heat, density, shear coefficient, coefficient of friction with steel, thermal conductivity) , Moisture content), and the structure and shape of the outlet nozzle (including the outlet-side resistor). Therefore, the heating conditions can be controlled by adjusting the structure and shape of the outlet resistor.

FIG. 2 schematically shows a method for connecting the barrel portion and the outlet nozzle portion. The shape of the outlet nozzle is a conical shape whose diameter decreases toward the outlet side, that is, a die shape. The feature of this structure is that the outlet nozzle gap with the outlet nozzle inner ring 9 can be easily changed by sliding the outlet nozzle outer ring 10. The shape of the outlet nozzle may be a conical shape whose diameter increases toward the outlet side, that is, a cone type. The feature of this structure is that the raw material is easily produced toward the outlet, and the risk of clogging inside the barrel can be reduced. In addition, the shape of the outlet nozzle can be cylindrical instead of conical.

The outlet nozzle is an important part that plays a role in adjusting the flow rate and pressure of the raw material. In addition to the outlet nozzle gap, the flow rate and pressure can be adjusted by adding grooves and protrusions that obstruct the movement of the raw material passing through the nozzle gap. The V-shaped groove 27 shown in FIG. The angle and direction of the V-groove is approximately the same as the blades of the cylinder for the outer ring, and approximately the same as the screw blades for the inner ring, so that the material passing through the outlet nozzle gap The depth of the V groove that can cause shearing is preferably about 1/2 to 1/3 of the nozzle gap. A protrusion may be provided instead of the V groove.

As for the groove or protrusion added to the outlet nozzle gap, in addition to the spiral shape, the groove can be provided in the axial direction and in the circumferential direction. For the rotating inner ring, it is effective to provide a groove in the axial direction in order to suppress the circumferential rotation. The number, depth, height, and spacing of grooves and protrusions are design matters, but the height of the protrusion is 1/2 the nozzle gap, the number is 4 at intervals of 90 degrees, and the circumferential groove is the outlet. As a guide, about 5 mm intervals are equally spaced in the axial direction of the slur.

The pressure adjustment of the raw material passing through the barrel can also be performed by arranging a structure on the outlet side that provides resistance to the flow of the extruded raw material. FIG. 3 is an explanatory view showing the embodiment. The raw material is pushed in the direction of the arrow between the outer ring and the inner ring of the outlet nozzle. By arranging the mesh or filter 22 on the outlet side of the outer ring of the outlet nozzle, resistance can be given to the flow of the raw material. The resistance of the net-like body can be adjusted by combining a plurality of different stainless steel meshes having different fineness (mesh number). In addition to the mesh, various filters can be used alone or in combination. In the figure, reference numeral 21 denotes a perforated plate, which is used for the purpose of reinforcing the mechanical strength of the mesh.

FIG. 4 is an explanatory view showing another embodiment in which the outlet nozzle is given resistance to the raw material flow. By arranging the parallel leaf spring 23 on the outlet side of the inner ring of the outlet nozzle, resistance can be given to the flow of the raw material. The resistance can be adjusted by combining various thicknesses, materials, and structures of the leaf springs. In the figure, reference numeral 24 denotes a resistance plate, which is used as a lid for the outlet gap. The material is selected in consideration of wear.

FIG. 5 is an explanatory view showing another embodiment in which the outlet nozzle is given resistance to the flow of the raw material. The front end of the outlet nozzle inner ring is formed as a conical core, and the front end of the outlet nozzle outer ring is constituted by a porous conical cap 25 arranged substantially in parallel with the gap. The resistance can be adjusted by combining various sizes, positions, and numbers of holes.

Since the extruded discharge is heated and subjected to pressure, it is deformed according to the structure and shape of the outlet nozzle. For example, in the case of Example 3, the particle size corresponds to the mesh size, in the case of Example 4, it is a thin flake shape, and in the case of Example 5, it is an elongated earthworm shape. Also, these effluents contain water vapor at high temperatures and often require cooling and drying. It is effective to introduce a crushing mechanism as a method of returning the shape of the deformed discharge to the original powder form and accelerating cooling and drying.
FIG. 6 is an explanatory view showing the embodiment. A rotating body arranged substantially in parallel with an appropriate gap is connected to the outside of the porous conical cap of Example 5, and the discharged matter is crushed using the gap and the rotating body. Here, the rotation has a feature that can be realized economically because the main motor for driving the inner ring of the screw and the outlet nozzle is used as a power source. Moreover, the crushing effect can be enhanced by making a plurality of holes in the rotating body or by notching a part of the holes.

The present invention is intended for an extruded product discharged through an extrusion process, and simplifies and rationalizes the entire process by incorporating a crushing operation into the extrusion process. The extruded product that is the subject of the present invention is extruded from a nozzle that is constricted (holed) on the surface of a conical (brass-shaped) structure. It is discharged from a hole diameter of several mm. Immediately after discharge, it is in the form of a worm, but when it falls into the storage container, it breaks into a pellet having a length of about several mm. If this is left as it is, particles that have a hardness that requires a considerable force at the fingertips or cannot be easily crushed. Crushing is effected by the pushing force provided in this spacing space and the shearing force generated between the approximately moving shape and size of the structure disposed relative thereto.

As another method of simultaneously realizing crushing, cooling, and drying, the discharged product can be passed through a vibrating screen. Vibrating sieves forcibly vibrate the raw materials to increase contact with air and to mix the 'koma' together with the material to be crushed on the sieve to break the bonds between the particles. Collapse. Further, if forced air cooling is performed by blowing air, water vapor is scattered and the cooling and drying effects can be enhanced.

In addition, the heat processing apparatus of this invention is not limited only to the above-mentioned illustration example, Of course, it can add various changes within the range which does not deviate from the summary of this invention.

The need for heat sterilization without sacrificing flavor and nutrition is strong in the food field. To achieve this purpose, ultra-high temperature sterilization is required, but its use is limited due to the high cost of the device. If ultra high temperature sterilization is realizable with the uniaxial extruder of this invention, it can apply to many food raw materials. In addition, rice bran and okara are discarded without being effectively used because they are susceptible to spoilage. However, since these raw materials are highly nutritious and have excellent health effects as foods, if they can be prevented and sterilized with an inexpensive device, the path to effective utilization will be opened.

Is the mechanism diagram of the entire heat treatment equipment Is an explanatory diagram of the relationship between the barrel and the outlet nozzle Is an explanatory diagram of an embodiment of the outlet nozzle Is an explanatory view of another embodiment of the outlet nozzle Is an explanatory view of another embodiment of the outlet nozzle Is an explanatory diagram of the crushing mechanism

Explanation of symbols

1 is the main motor of the extruder,
2 is a feeder extruder,
3 is the hopper,
4 is an anti-bridge nozzle
5 is a raw material passage,
6 is a feeder motor,
7 is the gear,
8 is a flow control motor,
9 is the inner ring of the outlet nozzle,
10 is an outer ring of the outlet nozzle,
11 is an inlet,
12 is a discharge part temperature sensor,
13 is a controller,
14 is an outlet temperature sensor,
15 is a cylinder,
16 is a screw,
17 is the screw blade on the entrance side,
18 is a cylinder blade,
19 is a screw blade,
20 is a discharge 21, a perforated plate 22 is a mesh, and / or a filter 23 is a parallel leaf spring 24, a resistor 25 is a perforated conical cap 26, and a crushing mechanism 27 is a V-shaped groove.

Claims (7)

A powder or granular raw material extruder is composed of a barrel that pressurizes and shears the raw material, and an outlet nozzle that controls flow rate and pressure. The barrel has blades on the outer surface of the screw and the inner surface of the cylinder. Heat treatment apparatus characterized by having a structure that is sheared between these blades, and an outlet nozzle having a structure that provides resistance to the flow of the extruded material A V-shaped groove or protrusion is attached to the outer ring and inner ring of the outlet nozzle according to claim 1 and the direction thereof is spiraled in substantially the same manner as the blades of the cylinder and the screw blades, respectively, and the raw material passing through the outlet nozzle gap is sheared. Heat treatment apparatus characterized by producing The heat treatment apparatus according to claim 1, wherein the structure for imparting resistance to the flow of the raw material is composed of a single or a plurality of nets and / or filters and / or porous bodies. 2. The heat treatment apparatus according to claim 1, wherein the structure for imparting resistance to the flow of the raw material is constituted by a spring elastic body disposed substantially perpendicular to the flow direction. 2. The structure for imparting resistance to the flow of the raw material according to claim 1, wherein the outlet nozzle inner ring tip is a conical core, and the outlet nozzle outer ring tip is arranged substantially in parallel with an appropriate gap therebetween. Heat treatment apparatus characterized by comprising a cap The heat treatment apparatus according to claim 1, further comprising a mechanism for crushing the discharged discharge material. 7. A heat treatment apparatus according to claim 6, wherein the crushing mechanism is constituted by a rotating body coupled to a screw.

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