WO2008004313A1

WO2008004313A1 - Apparatus for heat treatment of powdery/granular substance

Info

Publication number: WO2008004313A1
Application number: PCT/JP2006/313814
Authority: WO
Inventors: Kouji Oogaki; Kazumoto Iinuma; Yutaka Kawachi
Original assignee: Ricetech Corporation
Priority date: 2006-07-05
Filing date: 2006-07-05
Publication date: 2008-01-10

Abstract

An inexpensive heat treatment apparatus with which a powdery or granular substance which is a raw material to be treated is precisely heated in a short time. The heat treatment apparatus comprises an extruder for a powdery or granular material which comprises a barrel for pressing/shearing the material and an outlet nozzle for regulating flow rate and pressure. The barrel has a constitution in which the outer surface of the screw and the inner surface of the cylinder each has a blade attached thereto so that the material being extruded is sheared between these blades. Thus, a heat treatment apparatus which attains a high energy efficiency and is inexpensive is provided.

Description

Description Heat treatment equipment for granular materials

TECHNICAL FIELD The present invention relates to a heat treatment apparatus for heating powder or granular grain raw material for a short time. [Background Art] Generally, powdery or granular substances such as rice bran and soybeans are heated for a short time, for example, uniformly and accurately for 9 seconds at 1550 degrees Celsius (hereinafter abbreviated as 1550 degrees Celsius). There was no heating control device. For example, for sterilization of rice bran, Patent Document 1 shows an example of heating at 85 degrees Fahrenheit (30 degrees Celsius) for 20 minutes. Electromagnetic and infrared heating methods are suitable for this purpose but have poor energy efficiency and uniformity. The extruder (ex tr ude er) is suitable as a heating device because the raw material itself generates heat due to friction and shear during the raw material extrusion process. For example, FIG. 1 of Patent Document 2 and FIG. 3 of Patent Document 3 show examples. As a result, friction and shear were concentrated on the cylinder tube surface of the extruder, resulting in uneven temperature in the raw material, and the intended heat treatment could not be performed uniformly.

[Patent Literature 1] Japanese Patent Application No. 6-5 1 3 2 0 1 (1 page 4 example 1)

[Patent Document 2] U.S. Patents U.S.4, 7 4 1, 2 6 4 (Fig. 1)

[Patent Document 3] Patent Publication No. 2 9 5 6 6 2 2 (Figure 3 on page 3)

DISCLOSURE OF THE INVENTION

[Problems to be Solved by the Invention] When heating flour or granular cereals, various methods can be applied to a long time constant heat treatment such as several minutes to several tens of minutes as experienced in cooking. There aren't many ways to control heating for a few seconds. For example, in the process of sterilization of rice bran that achieves both the inactivation of lipase, which is the cause of oxidative rot of rice bran (so called ranch), and the sterilization of microorganisms and the preservation of nutrients such as vitamins contained in rice bran, the exact conditions of temperature and time Configuration and management are required. In other words, lipase can be inactivated by heating to 15 ° C. for several minutes with a frying pan or the like, but the vitamin contained in the rice bran decomposes and disappears during this heat treatment process. The heat treatment conditions that inactivate the lipase and preserve nutrients and flavors require a short and accurate control, for example, heating at 150 ° C. for 9 seconds. Ultra high temperature (UHT) powder sterilizers for this purpose use superheated steam, but not only the equipment and operating costs are high, but also yield loss, Processing costs will be several hundred yen. The raw material cost of rice bran is several to tens of yen per kilogram, so the sterilization cost is about 10 times more than that of the raw material. The present invention is to provide a UHT sterilizer by short-time heating that is realized at a cost equivalent to the raw material cost compared to per kg.

[Means for Solving the Problems] The extruder can use the heat generated by the friction and shearing of the raw material itself in the process of extruding the raw material, so that 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 is compressed into a lump in the barrel, the product temperature rises due to friction and shear heat at the part in contact with the cylinder surface, but heat is generated at other parts. If the thermal conductivity of the raw material is poor, there will be significant unevenness in the product temperature. For this reason, heat treatment becomes non-uniform and lipase inactivation and sterilization become insufficient. Rice bran has a very poor thermal conductivity, so according to experiments, the product temperature is as high as 50 ° C to 80 ° C. In the present invention, the raw material in the barrel is near the center of the passage and a very narrow passage. By trying to be sheared at a low temperature, it is intended to provide a heat treatment apparatus that eliminates uneven product temperature and is low in cost and energy efficient.

[0 0 0 5]

According to the present invention, a powder or granular raw material extruder is constituted by a barrel that pressurizes and shears a raw material, and an outlet nozzle that controls flow rate and pressure, and a blade is provided on each of the barrel screw outer surface and the cylinder inner surface. And the heat treatment apparatus is characterized in that the extruded material is sheared between these blades.

According to the present invention, the following actions can be obtained. For example, when the raw material is rice bran, the rice bran to be injected is extruded in the direction of the outlet by the screw blades between the screw and the cylinder. Sheared. If the passage gap is 5 mm and the height of both blades is 2.4 mm respectively, the rice bran will be sheared at the center of the passage instead of the pipe surface. The heat generated here spreads in all directions from the center, so product temperature unevenness is reduced. Furthermore, if the gap between the outlet nozzles is narrowed to 1 mm or less and the rice bran is sheared again, the product temperature will be further reduced. In addition, the height of the blade is increased to the full barrel gap near the entrance of the raw material to secure the extrusion force, and it is changed from about 1/2 or 1/3 to about 2/3 toward the exit. If the raw material is configured to be sheared at different positions in the passage, the raw material is agitated during the extrusion process, and the uniformity of the product temperature is further increased.

In addition, if the feedback control described in Examples 8 and 9 of the present invention is added, the target heat treatment can be realized at low cost without losing energy efficiency even if the temperature or humidity of the raw material to be injected changes. Can have an effect.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows the entire mechanism of an extruder as the best mode for carrying out the present invention. Hereinafter, the case where the raw material is rice bran will be described. However, the present invention is not limited to this, and the present invention is not limited to rice, wheat, beans, buckwheat, corn, and powders thereof, bran (rice cake), embryos, etc. Applicable. It can also be applied to tea leaves, spices, vegetables, fruits, mushrooms, mushroom culture media, plants, meat, seafood, pet food, and feeds that have been processed into powder or granules other than grains. The purpose of heat treatment of rice bran is to inactivate endogenous lipase and sterilize microorganisms contained in rice bran. Because the extruder for this purpose is often called a stabilizer after its use, Figure 1 is an overall view of the stabilizer. Next, the operation of the illustrated example will be described. Rice bran is poured into hopper 3 and through feeder 1 into the extruder barrel. The main part of the extruder consists of a barrel part, an outlet nozzle part and a main motor 1. The barrel part is composed of a cylinder 15 and a squeegee 16 with blades, and the gap between the two becomes the raw material passage 5, and the rice bran is heated by extrusion pressure, friction and shear. The outlet nozzle part is composed of an inner ring 9 and an outer ring 10, and the gap between the two is made narrower than the barrel gap, thereby acting as a valve that regulates the flow rate, and pressure is applied to the raw material passing through the barrel. generate. The screw 16 and the inner ring 9 at the outlet are mechanically coupled, and are driven by the main motor 1 to rotate. The raw rice bran passes through a passage formed by a gap between the cylinder 15 and the screw 16 and is pushed toward the outlet by a screw blade 17. Here, the height of the blade on the inlet side from the screw blade 17 is almost equal to the gap between the passages to ensure a sufficient pushing force. From the blade blade 19 onwards, the blade height is lowered, and at the same time, the cylinder blade 18 shown in broken lines is attached to the inner surface of the cylinder. Here, if the passage gap is H, the height of the screw blade is HI, and the height of the cylinder blade is H2, then each blade is set so that H = H 1-2-+ Η 2 + α. Machine Machine. Α is a clearance for preventing the upper and lower blades from coming into contact with each other, and is usually 0.1 to 0.3 mm. The height of the blade is, for example, H 1 = H-α near the entrance and Η 1 = (Η-α) 1 2 in the vicinity of the entrance, in the direction of the raw material (screw axial direction). . In addition, the angle 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, the angle of both is the same for simplicity. When the raw rice bran is pushed out using the barrel as described above, the rice bran is sheared as it passes through the part sandwiched between the 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 is reduced. In a normal extruder barrel, the cylinder is hollow and has no blades on the inner surface. Therefore, friction and shear are intensively generated on one cylinder surface, and heat is released from the cylinder iron pipe to the outside. For this reason, the cylinder tube surface of the passage becomes hot, but heat is not transferred to the inside, and significant temperature unevenness occurs in the passing material. According to a rice bran experiment, when the cylinder tube surface is 1550 ° C, the screw surface is 80 ° C, and a temperature difference of 70 ° C occurs. The temperature of rice bran rises rapidly near the exit of the barrel. If the outlet nozzle is completely closed, the rice bran is pushed back without being discharged, and is repeatedly heated and burnt by repeatedly rubbing and shearing in the barrel. When the gap between the outlet nozzles is widened slightly, the rice bran 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 of the cylinder and screw, shape, material and physical properties of rice bran (Poisson's ratio, specific heat, density, shear coefficient, coefficient of friction with steel, heat (Conductivity, moisture content). On the other hand, heat is generated at the outlet nozzle, and the amount of heat generated varies greatly depending on the structure and shape of the outlet nozzle. Also, since the barrel and outlet nozzle are connected, the internal heat generation varies depending on the combination of these structures and shapes.

[Example 1]

In Fig. 1, 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 exit nozzle gap between the exit nozzle and the inner ring 9 can be easily changed by sliding the exit nozzle outer ring 10. In the figure, the outlet nozzle outer ring is fixed by screwing into the cylinder inner surface and can be slid by turning the outer ring. If the outer ring is slid in the outlet direction, the exit nozzle gap can be increased as much as possible. In this structure, the outer ring can be slid while the inner ring is rotating, that is, during operation. Therefore, the outlet clearance can be automatically controlled not only by sliding manually but also by connecting to the motor 8 via the gear 7 as shown in FIG. The shape of the outlet nozzle can 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 easy to come out toward the outlet, and the risk of clogging inside the barrel can be reduced. In order to slide the nozzle outer ring 10, it is necessary to move it integrally with the barrel, which makes the structure complicated compared to the die type. In addition, the shape of the outlet nozzle can be cylindrical instead of conical. In this case, the exit nozzle gap is determined at the time of processing, so parts must be replaced to adjust the gap. The physical dimensions of the output nozzle gap are design matters, and the power varies depending on the power of the main motor, the number of revolutions, and the structure and dimensions of the barrel; Can be made. Figure 2 shows the relationship between the barrel and the outlet nozzle. The outlet nozzle is an important part that plays a role in regulating the flow rate and pressure of the raw material. In addition to the outlet nozzle gap, the flow rate and pressure adjustment pass through the nozzle gap. There is a method of adding grooves and protrusions that obstruct the movement of the raw material. The V-shaped groove 27 shown in Fig. 2 shows an example. The angle and direction of the V-groove is approximately the same spiral as the cylinder blades for the outer ring, and approximately the same spiral as the screw blades for the inner ring. The passing material can be sheared, and the depth of the V groove should be about 1/2 to 1/3 of the nozzle gap. A protrusion may be provided instead of the V-groove. With respect to 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 protrusions is 1/2 of the nozzle gap, the number of grooves is 90 degrees, 4 grooves, and circumferential grooves. The guideline is about 5 mm at regular intervals in the axial direction of the outlet slack.

[Example 2]

If the raw material passing through the barrel can be stirred, the temperature unevenness of the raw material due to internal heat generation can be further reduced. Since shear occurs between the cylinder blade and screw blade, if this position is changed in the direction of the outlet nozzle in the passage, the heat generation position is changed, and a stirring effect can be obtained. This can be achieved by changing the blade height HI in the direction of travel. That is, near the barrel entrance, start with H1 = H—α, then Η1 = 2 (Η—α) / 3, then Η1 = (Η—α) / 2, and then Hl = (Η— α) / 3, and then change the blade height so that Η1 = (Η-α) / 2. At this time, the height of the cylinder blade 加工 2 is processed so that it becomes Η 2 — Η 1— ”respectively. It is a design matter to determine the size of such a structure. However, for example, it is possible to arrange 2 pitch blades each to make a total pitch of 10. By this method, the position where the raw material is sheared is measured from the inner surface of the cylinder, and 0 in the traveling direction. Since Η / 3, Η / 2, 2 Η / 3, and 2/2 change, the internal heat generation position changes accordingly, and the product temperature becomes more uniform.

[Example 3]

The pressure adjustment of the raw material passing through the barrel can also be performed by arranging a structure on the outlet side that gives 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 placing a mesh or filter 22 on the outlet side of the outlet nozzle outer ring, resistance can be given to the flow of the raw material. The resistance of the mesh can be adjusted by combining multiple meshes with different mesh fineness (mesh number). In addition to the network, 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.

[Example 4]

FIG. 4 is an explanatory view showing another embodiment in which the outlet nozzle is given resistance to the flow of the raw material. Outlet nozzle By arranging the parallel plate panel 23 on the outlet side of the inner ring, 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 panel panel. 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.

[Example 5]

FIG. 5 is an explanatory view showing another embodiment in which the outlet nozzle is given resistance to the flow of the raw material. Outlet nozzle Consists of a conical core at the outlet end of the inner ring and a multi-hole conical cap 25 with the outlet nozzle outer ring tip arranged approximately in parallel with the gap. The resistance can be adjusted by various combinations of hole size, position, and number.

[Example 6] Since the extruded discharge is heated and subjected to pressure, it deforms 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 deformed discharge shape to the original granular 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, rotation is economically realized because the main motor that drives the screw and the inner ring of the outlet nozzle is used as the power source. Moreover, the crushing effect can be enhanced by making a plurality of holes in the rotating body or by cutting out a part of it.

[Example 7]

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 material to increase contact with air and break the bond between the raw materials due to collisions between the raw materials and foreign materials. Furthermore, if forced air cooling is performed by blowing air, water vapor is scattered and cooling and drying effects can be enhanced.

[Example 8]

Fig. 7 shows a control block diagram for automatically controlling the temperature of the discharged material to the target value. The feature of this example is that the temperature sensors indicated by reference numerals 1 2 and 14 in FIGS. 1 and 7 are attached to the extruder, and the sensor information is input to the controller 1 3, and the controller 1 3 The target temperature control program is operated, and the processing temperature is controlled to the target value by controlling the extruder through various motors whose outputs are denoted by reference numerals 1, 6, and 10. In the figure, the inputs of the controller 13 are a temperature sensor 14 near the outlet of the extruder and a temperature sensor 12 at the discharge section. The temperature sensor 14 near the outlet has a steep temperature gradient in this part and is particularly important for control characteristics, so three sensors are mounted side by side in the outlet direction. On the other hand, the output of the controller 13 is controlled by the main motor 1 (Motor A), the number of revolutions of the extruder, the feeder drive motor 6 (Motor B), and the flow rate control motor 8 (Motor C). ) Used to control the amount of processed material discharged. The procedure for realizing the target heat treatment from the mechanism shown in Fig. 1 and the controller shown in Fig. 7 is as follows. First, the condition parameters for heat treatment are determined from preliminary experiments. In other words, the target temperature condition is mainly determined by the main motor speed and the gap between the outlet nozzles. Therefore, the flow control position is manually changed while rice bran is continuously supplied to the extruder, and the slider position in this case is Measure the values of temperature sensors 1 4 and 1 2 to determine the combination of parameters that achieves a state close to the target. The relationship between these input / output parameters is written to the controller 13 as a target reference value setting program. Next, the difference delta 1 between these input target reference values and the actual sensor value is calculated, and the controller 13 heat processing program is created so that delta 1 becomes zero. In other words, the heat treatment program calculates the correction value beta 1 for the output target reference value of the motor A rotation speed control value and the motor C flow rate control value for the input system deviation delta 1, and the rotation speed control And flow control. Next, measure the discharge amount and discharge temperature in the above state, and manually measure the target reference value for supply control that balances the discharge amount by changing the rotation speed of motor B. Next, the input system deviation delta 2 from the target reference value is calculated for the actual exhaust temperature sensor value and other sensor values, and the feeder one supply amount control program is set so that delta 2 becomes zero. create. That is, in the feeder-one supply amount control program, the correction value Beta2 is calculated from the output system target reference value of the rotational speed control value of the motor B for the input system deviation delta2, and the supply amount control is performed. [Example 9]

Fig. 1 also shows a mechanism that prevents the rice bran from being caught in the hopper 3 by effectively using the heat of the discharged raw material. Bridge is a phenomenon in which raw materials are connected together to form a bridge and create a cavity in the hopper. This is a physical phenomenon that often occurs when powder or granular materials are injected. When bridging occurs, the raw material is disturbed by the bridge and cannot be successfully injected into the extruder. In FIG. 1, the heat flow is piped from the exhaust inlet 11, and blown from the bridge prevention jet nozzle 4 attached to the hopper 3 through the pump P toward the raw material. As a result, the effect of two birds with one stone can be obtained, which prevents the bridging while evaporating the water contained in the raw material and drying the rice bran. The rice bran has a moisture content of 10 to 13%, and a significant proportion of the drive energy is used for water evaporation. This feedback mechanism contributes greatly to improving energy efficiency. Install filters and valves to prevent the exhaust from flowing back through the pipe. In addition, heat can be recirculated using a heat pipe instead of the intake port. In addition, the heat processing apparatus of this invention is not limited only to the above-mentioned illustration example, Of course, in the range which does not deviate from the summary of this invention, a various change can be added.

[Industrial applicability] 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 in the past, a biaxial excavator and a superheated steam method have been used. These disadvantages are expensive equipment and poor energy efficiency. One axis of the present invention! If ultra-high temperature sterilization can be realized in one, it can be applied to many food ingredients. In addition, rice bran and okara are discarded without being effectively utilized because they are susceptible to corruption. However, since these raw materials are highly nutritious and have excellent health benefits as foods, if they can be prevented and sterilized with an inexpensive device, the path to effective utilization will be opened.

[Brief description of the drawings]

[Fig. 1] is the overall mechanism of the heat treatment equipment

[Figure 2] is an explanatory diagram of the relationship between the barrel and the outlet nozzle

[Fig. 3] is an explanatory diagram of an embodiment of the output nozzle

[Figure 4] is an explanatory diagram of another embodiment of the outlet nozzle

FIG. 5 is an explanatory diagram of another embodiment of the outlet nozzle

[Figure 6] is an illustration of the crushing mechanism

[Fig. 7] is a control block diagram of the heat treatment apparatus

[Explanation of symbols]

1 is the main motor of the extruder,

2 is an extruder for feeders,

3 is a hopper,

4 is a bridge prevention fume nozzle,

5 is raw material passage,

6 is a feeder motor,

7 is gear,

8 is a flow control motor,

9 is the output nozzle inner ring,

1 0 is the outer nozzle outer ring,

1 1 is the inlet,

1 2 is the discharge temperature sensor,

1 3 is the controller, 1 4 is the outlet temperature sensor,

1 5 is the cylinder,

1 6 is Skew,

1 7 is the entrance piece j One screw,

1 8 is the cylinder blade,

1 9 is screw blade,

2 0 is emissions

2 1 is perforated plate

2 2 is mesh and / or filter

2 3 is a parallel leaf spring

2 4 is a resistor

2 5 is a porous cone cap

2 6 is the crushing mechanism

2 7 is V-shaped groove

It is.

Claims

The scope of the claims

[Claim 1]

A powder or granular raw material extruder consists of a barrel that pressurizes and shears the raw material, and an outlet nozzle that controls the flow rate and pressure. The raw material is extruded by attaching blades to the outer surface of the barrel and the cylinder surface. The heat treatment apparatus is characterized in that it is configured to be sheared between these blades.

[Claim 2]

2. The barrel according to claim 1, wherein the sum of the height of the blade on the outer surface of the screw and the height of the blade on the inner surface of the cylinder is slightly smaller than the barrel gap through which the raw material passes, and the angles of the blades cross each other. Thus, the heat treatment apparatus is configured so that extrusion and shearing of the raw material are compatible.

[Claim 3]

The height of the screw blade according to claim 2 is raised to the full barrel gap near the raw material entrance to secure the pushing force, and about 1/2 or 1/3 to 2/3 toward the outlet. The heat treatment apparatus is characterized in that the raw material is sheared at different positions in the passage by varying the degree.

[Claim 4]

2. The heat treatment apparatus according to claim 1, wherein the outlet nozzle comprises an inner ring coupled to the screw and an outer ring coupled to the cylinder, and the output flow rate of the raw material is determined by the size of the nozzle gap sandwiched between the inner ring and the outer ring. A heat treatment apparatus characterized by adjusting the pressure.

[Claim 5]

The outlet nozzle inner ring and outer ring according to claim 4 are formed in a conical shape whose diameter increases or decreases in the axial direction, and the relative position of the inner ring and the outer ring is changed manually or automatically to adjust the size of the nozzle gap. The heat processing apparatus characterized by the above-mentioned.

[Claim 6]

Grooves or protrusions that suppress the circumferential and axial movement of the passing material are attached to one or both of the outer ring and the inner ring of the outlet nozzle according to claim 4 or claim 5, and the raw nozzle does not feed the raw material. A heat treatment apparatus characterized by causing a disconnection.

7. The heat treatment apparatus according to claim 1, wherein a structure that provides resistance to the flow of the extruded material is disposed on the outlet side.

8. A heat treatment apparatus characterized in that the structure for imparting resistance to the flow of the raw material according to claim 7 is composed of a single or a plurality of nets, a net or a filter, and / or a porous body.

9. The heat treatment apparatus according to claim 7, wherein the structure for imparting resistance to the flow of the raw material is composed of a spring elastic body disposed substantially perpendicular to the flow direction.

10. The structure for imparting resistance to the flow of raw material according to claim 7, wherein the outlet nozzle inner ring tip is a conical core and the outlet nozzle outer ring tip is the same. A heat treatment apparatus comprising a porous conical cap arranged substantially in parallel with an appropriate gap

11. The heat treatment apparatus according to claim 1, further comprising a mechanism for crushing the extruded discharge.

12. The heat treatment apparatus according to claim 11, wherein the crushing mechanism is constituted by a rotating body coupled to a screw.