JPH119197A - Production of fish feed pellet and apparatus for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing pellets, sterilizable at the time of production and sinkable without floating with a high productivity by using a nonpregelanizing starch at a low unit price as the starch in a feed raw material for cultured fishes prepared by formulating a fish meal with a grain flour, oils and fats, a nutrient, etc. SOLUTION: This method for producing fish feed pellets comprises using a fish feed raw material prepared by mixing a fish meal with a grain flour, oils and fats, a nutrient, water, etc., with a twin-screw extruder. A nonpregelatinized starch is used as the starch in the fish feed raw material and charged into a barrel 11 without being preheated and the starch is heated, pregelatinized and then deaerated under an atmospheric pressure of 0 to -440 mmHg including the opening of the interior of the barrel 11 to the atmosphere to raise the density, extruded through a die in a state of suppressed puffing, cut with a cutter and formed into the pellets. Thereby, the pellets are made to sink when charged into seawater.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a pellet-shaped fish bait for use in a fish farm. More specifically, the present invention relates to a method for producing pellets in which fish bait sinks, and also relates to an apparatus for producing the pellets.

[0002]

2. Description of the Related Art Along with the decrease of marine resources, fishery cultivation along the coast and research on fishery have been actively carried out as a measure to meet the demand. These farmed fish are fed a feed mix in addition to the raw feed. Formula feeds include dough mixed with water and kneaded, and EP pellets extruded with an extruder. EP pellets float on the surface of the sea, and if the sinking speed is low, they are washed away by the tide, or large groups of seagulls gather toward the EP pellets, intercepting the floating bait and going into the mouth of the cultured fish. There is also a situation in which farmed fish do not come to eat the food floating on the hordes of seagulls. This wastes food and increases costs.
In addition, the administration of sufficient food is hindered, and there is a problem that the growth of the cultured fish is poor in proportion to the feeding of the food.

[0003] A general manufacturing method will be described based on a skeleton diagram of a fish compound feed pellet extruder shown in FIG. From the twin-screw conditioner 2 having the hopper 1 into which the fish bait raw material is fed, the raw material of the fish bait is supplied to the input port 4 of the twin-screw extruder 3.
Supplied to A feed screw and a kneading disk are appropriately incorporated into two feed screw shafts provided in parallel in the barrel and rotated in the same direction by a driving device 6, and are extruded into a cylinder from a die 8 at the tip, and are then cut by a cutter (not shown) on the front surface. It is to be cut into pellets of a predetermined size. In the barrel, for example, a heater for heating is provided in a first zone A and a middle zone B, and a cooling pipe is provided in a second zone C.

[0004] As a raw material for fish feed, for example, in the case of hamachi adult fish, 70% by weight of fish meal, 10 to 20% of cereal powder such as pregelatinized tapioca starch and defatted soybean powder, nutrients, water, oil, etc. Those having a ratio of 20% to 10% are used. The mixed fish bait raw material is put in the hopper 1, mixed in the twin-screw conditioner 2, and supplied to the input port 4 of the twin-screw extruder 3. Water is further added in the former zone A of the barrel to adjust the water content. In the barrel, it is heated in the former zone A and the middle zone B, usually kept at the barrel temperature of 50 ° C. to 120 ° C., and after efficient kneading, it is sequentially cooled in the latter zone C to reach about 70 ° C. at the exit of the die 8. The held and extruded cylinder is cut into pellets by a cutter.

[0005] When the pellets thus produced are extruded from the die 8 by pressurized water, steam, or the like in the raw material of the fish bait, the extruded product is immediately reduced from the pressurized state inside the extruder to normal pressure. Due to the pressure drop, starch mainly forms a cellular skeleton and expands. When this swollen pellet is administered at a fish farm, there is a disadvantage that it does not sink and float on the sea surface. Therefore, in order to produce sinking pellets, if the water content in the barrel is 25% or less, the pellets swell and break, making molding impossible. If it is 40% or more, it is too soft and cannot be molded, so the content is 25% to 40%. Therefore, the raw material of the fish bait uses a mixture of pregelatinized starch to improve the binding property and the molding, and the temperature of the raw material of the fish bait in the barrel is 60 ° C.
It was kept at 70 ° C., and was manufactured at a low rotational speed so that the temperature inside the barrel would rise more than necessary and not expand during extrusion. Therefore, there was a problem that the throughput was small and the productivity was poor.

[0006]

In order to sink the pellets of fish farming food without floating in the conventional production method, wheat flour to be added to cereal flour, that is, starch which is pregelatinized without using raw one is used. When used, the unit price is about three times higher than the raw one, and the raw material cost of the fish bait increases, which is a problem among fish farmers. In addition, since the rotation speed of the twin-screw extruder shaft is kept low to suppress expansion, there is a problem in that the raw material transport amount is reduced, the processing capacity is low, and the productivity is poor. Further, since the barrel temperature is set to a low 60-70 °, there is a problem that if the raw material of the feed is not sufficiently sterilized and the product moisture is high, there is a risk of spoilage. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the related art, and has as its object to provide a method for producing fish bait pellets at a low cost. Another object of the present invention is to provide a machine for producing the pellet.

[0007]

In order to achieve the above-mentioned object, a method of the present invention uses a twin-screw extruder to feed raw material containing fish meal, grain powder, oil and fat, nutrient, water and the like. This is a method for producing pellets.The starch in the raw material of fish bait is not pregelatinized and is charged into the barrel of a twin-screw extruder without preheating and heated to pregelatinize the starch. It was degassed at a pressure of 0 to 440 mm of mercury, including being open to the air, and was formed by extruding from a die and cutting with a cutter in a state where the density was increased and the expansion was suppressed, and formed into pellets. Things.

Further, in a twin-screw extruder for heating and kneading the fish feed raw material supplied by the feeding means, the temperature in the barrel up to the first kneading disk following the feed screw is gradually increased to prepare a pre-gelatinized starch. A first heating zone for heating, a second heating zone for heating the temperature in the barrel from the feed screw to the second kneading disk to a temperature higher than the first heating zone to gelatinize the starch,
It comprises a degassing zone for releasing air, evaporative gas, water vapor and the like in the barrel after the starch is pregelatinized, a cooling zone for gradually lowering the temperature and increasing the raw material density, and a zone for forming pellets. Evaporative gas, water vapor, and the like exhausted from the degassing zone are returned to the fish feed material inlet or the preceding zone.

Fish flour, cereal flour containing non-gelatinized starch,
The raw material of the fish bait combined with nutrients, water and the like is fed by a screw while raising the temperature to 100 ° C. to 150 ° C. in a first heating zone of a twin-screw extruder, and kneaded by a first kneading disk. In the second heating zone, the starch is heated to 150 ° C. to 250 ° C. to gelatinize the starch, feed it with a screw, knead it with a second kneading disk, fully gelatinize it, strengthen the binding power, sterilize it and increase the temperature. The degassing zone releases the generated gas and water vapor to the exhaust or the atmosphere to lower the pressure, remove moisture, and release heat. In the last cooling zone, the temperature is lowered to increase the density, extruded into a cylindrical shape from the die 6 and cut into pellets having a length of about 1.0 to 1.5 times the diameter with a cutter. The temperature is lowered, the gas and water vapor are extracted, and the density increases, and the expansion phenomenon is suppressed by the reduction of air and moisture.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 omits a hopper 1, a two-axis conditioner 2, a heater and a cooling pipe described in the prior art.
An embodiment of the present invention will be described based on the above.

The twin-screw extruder 3 has barrels 11A-
11E is concentrically connected and is horizontally supported by a machine base 12 with a stay 13. At the center of the barrel, a cocoon-shaped hole is cut in symmetry with the center axis, and two screw shafts 14 are inserted therein. A screw F and a kneading disk K are assembled together on this shaft. For example, an F120L lead screw F1 having a trapezoidal lead of 120 mm in order,
F80L feed screw F with 80mm lead
2. A feed screw F3 of F50L having a lead of 50 mm is arranged, and then the thickness is shifted by 90 ° in order of 2
4 K25 × 4 kneading disks K of 5mm
1. A biaxially combined F50L feed screw F4, K25 × 6 kneading disk K2, F80L feed screw F5, and F50L feed screw F6 are used.

A deaeration frame 15 having an intake chamber 15a at the top of the eyebrow-shaped hole, which is a feature of the present invention, and opening at the center upper surface.
(FIG. 3) is interposed between the barrels 11D and 11E. This position is where the air on the inlet side is blocked by the kneading disk K2 and the pool on the feed side in front of the die 6 is filled with the raw material for the fish bait, and the air on the exit side is cut off by the fish feed raw material. is there. The die 16 is attached to the tip barrel 11E. A cutter rotated by a motor is provided on the front surface.

The two screw shafts 14 can be variably rotated in the same direction by a motor 6 with a speed reducer built in a drive box 17. Further, barrels 11A, 11B, 11C, 1
In 1D and 11E, a cooling pipe and a heater are attached to the outer periphery, and the temperature in the barrel can be set by appropriately selecting and adjusting the use, and is measured by a thermometer. In this embodiment, cooling is performed in the barrel 11E.

The deaeration frame 15 is, as shown in FIG.
Is degassed by a vacuum pump 19, for example, a water-sealed vacuum pump manufactured by Kashiyama Kogyo Co., Ltd. through a check valve (not shown) from a steam hose 18 connected to the pump. A vacuum gauge for monitoring the degree of vacuum in the degassing chamber is provided. In the vacuum pump used in this embodiment, the degree of vacuum is also adjusted by adjusting the suction force adjusting valve 20 interposed in the deaeration port. Further, it is also performed by adjusting the barrel temperature to adjust the evaporation amount of steam. The degassed steam gas is returned to the preceding zone if necessary. In this embodiment, the water is returned to the fish bait raw material inlet in a warm water state. In this manner, the amount of heat and water can be effectively used, and the preliminary heating can be omitted. Also, the palatable substances contained in the raw materials, particularly fishmeal, etc. sucked out together with the steam are recovered. Further, by increasing the amount of water before deaeration, the kneading and mixing operations can be improved without lowering the power load.

Experiment Experiment 1 An experiment was conducted in the above-described twin-screw extruder specification. ○ Ingredients: fish meal ... 70% cereal flour ... 16 to 25% flour for pregelatinization 10 to 20% Nutrient, oil, etc. ... 5% to 15% ○ Experimental results are shown in Tables 1 and 2.

[0016]

[Table 1]

[0017]

[Table 2]

Table 3 shows an explanatory chart for comparing Tables 1 and 2.

[Table 3]

The lower the temperature of the pellet immediately after extrusion from the die, the more effective it is to suppress expansion. Degassing increases the density and ensures that the pellet sinks. The sedimentation speed changes depending on the degree of deaeration, and the speed increases relatively as the degree of vacuum increases.

According to various experiments, the condition of the sinking condition is as follows: o Moisture (moisture during operation of the part before degassing) ... 30 to 35
%: When it is less than 30%, the binding force is small and bulky, and when it is more than 35%, it becomes sticky and does not become pellet. 22.5% to 35% ...... Effective for water vapor in this range. Temperature (11D in FIG. 2): 160 ° C. to 260 ° C. Raw starch (not pre-gelatinized) can be used and sterilization can be performed. O Degassing: 0 to -440 mm of mercury released to the atmosphere O Screw rotation speed: 100 to 150 r. p. m. Is common.

[0021]

As described above, according to the present invention, degassing removes air, gas, and moisture, thereby increasing the density of the raw material, and also removing heat to lower the temperature of the product, thereby suppressing expansion. Further, by degassing, it is possible to increase the water content between the first kneading disc and the second kneading disc by circulating heated water containing a palatability substance and the like collected by degassing. The kneading action can be improved, and sterilization can be performed by raising the temperature further, so that preheating is not required, the gelatinization of starch is sufficiently promoted, the binding force of the pellet is strengthened, and the expansion is further suppressed by the synergistic effect. . Since non-gelatinized starch can be used, the production cost can be significantly reduced. The denser pellets settle reliably, eliminating waste of food and lowering aquaculture costs. The sedimentation speed can be adjusted by the degree of deaeration. Furthermore, the number of rotations of the screw is increased, and the productivity is increased. By interposing a deaeration frame between the barrels of the barrel split type extruder, application to the conventional machine is easy and assembly work is simple. In addition, by feeding back steam or the like during degassing, replenishment of water and calorie can be performed, and economical operation can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an extruder.

FIG. 2 is a cross-sectional view of a screw portion of the present extruder main unit with a deaeration frame interposed.

FIG. 3 is a perspective view showing a degassing frame.

FIG. 4 is a diagram showing a degassing system.

[Explanation of symbols]

11A, 11B, 11C, 11D, 11E Barrel 14 Screw shaft 15 Deaeration frame 16 Die F1, F2, F3, F4, F5, F6 Feed screw K1, K2 Kneading disc

Claims (3)

[Claims] 1. A method of producing fish feed pellets using a twin-screw extruder from a feed material containing fish meal, cereal powder, oil and fat, nutrient, water, etc., wherein starch in the fish feed material is pregelatinized. 0 m of mercury including charging the barrel into a twin-screw extruder without heating, preheating it, heating it to gelatinize the starch, and then opening the barrel to the atmosphere
Fish pellets characterized by being degassed at an air pressure of m to -440 mm to increase the density to suppress swelling, extruded from a die, cut by a cutter to form pellets, and sink when thrown into seawater. Manufacturing method. 2. In a twin-screw extruder for heating and kneading fish feed materials fed by a feeding means, the temperature in a barrel up to a first kneading disk following a feed screw is gradually increased to convert the raw material into gelatinized starch. A first heating zone for pre-heating, and a second heating zone for heating the temperature in the barrel from the feed screw to the second kneading disk to a temperature higher than the first heating zone to gelatinize the starch,
It consists of a deaeration zone for releasing air, evaporative gas, water vapor, etc. from the barrel after starch is pregelatinized, a cooling zone for gradually lowering the temperature to increase the density of the raw material, and a zone for forming pellets. Fish bait pellet manufacturing equipment. 3. The evaporative gas exhausted from the degassing zone,
3. The apparatus for producing fish bait pellets according to claim 2, wherein steam or the like is returned to a fish bait raw material input port or a preceding zone.