JPH11341952A - Addition of oil and fat to porous feed and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for industrially and extremely effectively adding oil and fat to porous feed, capable of remarkably increasing addition amount of oil and fat to the porous feed, improving mixing ratio of oil and fat to the feed without making the surface of the feed sticky with oil and fat, and continuously carrying out addition of oil and fat by successively repeatedly carrying out specific two operations. SOLUTION: Porous feed having large particle diameters and oil and fat are put into a hermetically closing continuous mixer, and operation for keeping the interior of the continuous mixer under reduced pressure and then instantaneously opening the pressure from the reduced pressure state to atmospheric pressure while mixing the porous feed with the oil and fat is repeatedly carried out by arbitrary frequency. At this time, the porous feed having the large particle diameters has preferably >=10 mm particle diameter and the reduced pressure is preferably <=-500 mmHg based on the atmospheric pressure, and further, treating time of operation for opening to atmospheric pressure is preferably within the range of 10 sec.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the addition of fats and oils to porous feed used for fish feed and the like.

[0002]

2. Description of the Related Art As fish feed, small fish such as sardines, which are conventionally called "raw feed", have been used in recent years. Feed made from cereals and other ingredients using soybean meal and soy flour as a protein source has been increasingly used.

[0003] Since these fish farm feeds are put into water when feeding, in the case of powder, it has to be mixed with a liquid such as water once and kneaded, which is troublesome. For this reason, conventionally, granules have generally been produced as pellet feed. Pellet feeds have been conventionally produced in large quantities for livestock such as chickens and pigs, and can be produced at relatively low cost, and can be produced without additional facilities, and are therefore commonly used.

[0004] However, even if the feed is formed into pellets, if the feed is fed into water at the time of feeding, the pellets may break down and contaminate the water quality. In addition, there was a disadvantage that the pellet particles easily sink in water due to their large specific gravity. Since swimming fishes mainly have the property of taking bait floating in water, bait once settled to the bottom is left behind, and there is a problem that the bait rots and pollutes the water quality.

[0005] Under these circumstances, floatable porous feed has come to be used as fish feed.
The porous feed is produced by a molding machine called an extruder or an expander, unlike a pellet formed by a pellet mill.

[0006] The porous feed is formed by mixing fish meal, shell powder, etc. with water, heating the mixture with steam, further performing cooking under pressure, and then extruding from a nozzle to expand. The obtained pellet-shaped feed has a porous shape with many voids.

[0007] Since this fish feed is porous, it has a low specific gravity and easily floats on water. In addition, since it is manufactured in this manner, starch and the like are partially gelatinized and hardened, and a property of being hardly broken is imparted. Therefore, there is a merit that fish can be easily eaten even when put in water, and there is almost no risk of polluting the water quality.

[0008] A further important matter for fish feed is to improve the addition rate of fats and oils as an energy source. In order to obtain a nutritional composition similar to that of raw feed, it is necessary to add as much oil and fat as possible. On the other hand, even if fats and oils are added from the viewpoint of handling of fish feed, etc., it is necessary that no fats and oils remain on the surface of the feed and that the surface condition is not sticky, and thus various studies have been made. The present applicant has already filed several applications (for example, see Japanese Patent Application Laid-Open No. 2-138944).

As another method, a mixture of pellet feed and oil and fat is put in a closed container, and the inside of the closed container is depressurized by a vacuum pump for a predetermined time while rotating the closed container to mix with the pellet feed. After the pressure is reduced, the lid is opened to open to the atmosphere, then the pressure is reduced again and the operation of opening to the atmospheric pressure is repeated several times (Japanese Patent Application Laid-Open No. 9-1997).
No. 182561).

[0010]

However, in such a method of simply repeating depressurization and opening to the atmosphere,
In the case of small-particle-diameter pellet feed, the intended purpose can be achieved for the time being. There is a disadvantage that it decreases.

It is an object of the present invention to solve the above-mentioned problems and to provide a more practical method for adding fats and oils and a device therefor.

[0012]

According to the present invention, a method for adding fats and oils is provided as follows in order to solve the above problems.

That is, the inside of the continuous mixer is kept under reduced pressure while the porous feed having a large particle diameter and the fats and oils are stirred and mixed in a closed type continuous mixer (hereinafter referred to as a continuous mixer). The operation of opening downward is repeated an arbitrary number of times.

It is desirable that the degree of pressure reduction inside the continuous mixer is maintained at -500 mmHg or less based on the atmospheric pressure. It is desirable that the reduced pressure holding time be maintained for at least 30 seconds after the set degree of reduced pressure is reached.

When the inside of the continuous mixer is released from the reduced pressure state to the atmospheric pressure, it is necessary to perform the operation immediately. The time for returning to the atmospheric pressure depends on the size of the continuous mixer, but it is usually preferably within 5 seconds, particularly preferably 2 to 3 seconds.

It is preferable that the step of maintaining the reduced pressure and the step of opening the chamber under the atmospheric pressure using a continuous mixer are performed a plurality of times as one operation step. Usually, it is sufficient to repeat this operation four times, and even if this operation is repeated more than that, the amount of adsorption is saturated and is not effective.

[0017] The continuous mixer is a closed type continuous mixer provided with a means for maintaining airtightness during continuous charging and discharging of the porous feed, and a stirring device provided in the continuous mixer.
It is composed of an atmosphere release valve, a vacuum pump for evacuating the inside of the continuous mixer, and the like.

As the closed type continuous mixer, a container fixed type such as a ribbon type or a paddle type is preferable, and a continuous type such as a ribbon screw type is desirable.

As a means for maintaining airtightness when the porous feed is charged or discharged, a rotary valve, a double damper, or the like can be used. The vacuum pump may be of any type as long as a sufficient degree of vacuum can be obtained.

The air release valve may be operated manually or automatically by a solenoid valve or the like, and may be repeatedly opened and closed at set time intervals.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the method for adding fats and oils according to the present invention will be described below.

FIG. 1 shows the overall configuration of a porous feed production apparatus.

The porous feed producing apparatus 30 is of a continuous type, and a mixer 1 for mixing and stirring the raw materials, an extruder 2 for kneading and extruding the mixed and stirred raw materials under pressure, and a drying process for drying the formed porous feed. Dryer 3, continuous mixer 5 for adding fats and oils, cooler 4 for cooling, and vacuum pump 1
1 and so on. A is a raw material to be charged, B is water and other liquid additives to be added (including internally added fats and oils), C is steam to be supplied, and D is fats and oils added from the outside.

In the mixer 1, the raw material A mixed in a predetermined amount
, Water and other additive liquid B are charged, stirred and mixed. At this point, a portion of the fat may be added. Mixer 1
The raw materials mixed in are sent to the extruder 2 and molded. The extruder 2 kneads the raw materials while maintaining the inside at a high pressure and a high temperature by heating the high pressure steam and the barrel in the cooking section. As a result, the starch in the raw material is turned into α, and the protein is denatured by heat to form a digestible form, which is extruded from a nozzle provided at the outlet.

When the raw material is extruded from the nozzle, the pressure is released instantaneously, so that a porous feed having a large number of voids therein can be obtained. Since the obtained porous feed still contains a lot of water, it is sent to the dryer 3 and dried until the water reaches a predetermined value. The high-temperature porous feed treated in the dryer 3 is sent to a continuous mixer 5 for adding fats and oils.

The continuous mixer 5 has an inlet and an outlet,
As shown in FIG. 2, rotary valves 10 and 13 are provided, whereby the inside of the continuous mixer 5 is kept airtight. The vacuum pump 11 is connected to the continuous mixer 5 by a pipe 22, and is reduced to a predetermined pressure. Further, the continuous mixer 5 is provided with an atmosphere release valve 21 for instantaneously opening the inside of the mixer 5 to the atmospheric pressure.

The continuous mixer 5 is supplied with a necessary amount of fat or oil together with the porous feed or in batches (not shown). As a method of supplying the fat or oil, the fat or oil may be poured together with the feed, or the fat or oil may be atomized and sprayed using a nozzle. It is also preferable to add batchwise from a plurality of locations in the continuous mixer.

The porous feed is gradually conveyed to the outlet side while being mixed with fats and oils inside the continuous mixer 5. that time,
The atmosphere opening valve 21 is appropriately operated, and the inside of the continuous mixer 5 is temporarily opened to the atmosphere. The opening and closing of the atmosphere release valve 21 are repeated at predetermined intervals. The porous feed to which the fat or oil has been added by the continuous mixer 5 is sent to the cooler 4 and cooled to room temperature. Then, if necessary, it is passed through a sieve or the like to remove the powder component, and the product is produced.

Therefore, the fats and oils are added in the continuous mixer 5 and the pressure reduction and the opening to the atmospheric pressure are repeated inside the continuous mixer 5, so that the fats and oils penetrate into the voids formed on the surface of the porous feed. In addition, since a reduced pressure state is maintained in the central portion of the porous feed than in the surface portion, a pressure difference is generated, and as a result, the fat and oil in the surface portion is suction-transferred to the central portion, and the surface portion is wet with the fat and oil. A high ratio of fats and oils can be added to the porous feed without becoming in a state of being mixed.

(Example) After the feed raw materials were uniformly mixed by the mixer 1, the porous feed (16.
5 mmφ × 16.5 mmL). The obtained porous feed was placed in the dryer 3 and dried until the water content became 9 to 10%.

Next, a diameter of 711 mm and a length of 6200 m
m with a porous feed to a continuous mixer for fat and oil addition in which a barrel is provided with a rotary valve at each inlet and outlet, and 8.5% of fat and fat with respect to the porous feed. At a rate of While the vacuum pump 11 is operating, the atmosphere release valve 21 is closed to reduce the degree of pressure reduction to -500 mmHg, and this state is maintained for 30 seconds.

Next, the atmosphere release valve 21 was opened, and the inside of the continuous mixer 5 was returned to the atmospheric pressure in 2 seconds. When the atmosphere release valve 21 is closed after holding this state for 8 seconds, the pressure in the oil / fat addition continuous mixer is reduced. After maintaining the pressure reduction degree at -500 mmHg for 30 seconds, the air release valve 21 was opened again to return the pressure to the atmospheric pressure to obtain a fat-containing porous feed.

As a result of measuring the amount of fats and oils adsorbed, 15.2% of fats and oils were adsorbed. The surface of the product was not sticky with oil or fat.

On the other hand, for comparison, the same procedure as described above was carried out except that the atmosphere release valve 21 was opened and held for one minute in the above method. As a result, the amount of adsorbed fat was almost the same, but the surface of the porous feed was sticky with fat.

[0035]

According to the method for adding fats and oils of the present invention, the amount of fats and oils to be added to the porous feed can be greatly increased since the air is released to the atmosphere at the time of depressurization, and the surface of the fats becomes sticky with fats and oils. Without increasing the mixing ratio of fats and oils in the feed.

Further, the addition of fats and oils can be performed continuously, and the pressure can be intermittently reduced by a simple operation of the valve, which is industrially very effective.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an example of a feed production apparatus according to the present invention.

FIG. 2 is a view showing an example of the structure of a fat and oil adding apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mixer 2 Extruder 3 Dryer 4 Cooler 5 Continuous mixer for oil and fat addition 10, 13 Rotary valve 11 Vacuum pump 12 Atmospheric release valve 20 Additive mixer barrel 21 Atmospheric release valve 22 Pipe 30 Porous feed production device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ao Uchiyama Nisshin Flour Milling Co., Ltd. 1-25-1 Kanda Nishikicho, Chiyoda-ku, Tokyo Nisshin Flour Milling Co., Ltd. Inside the corporation

Claims (7)

[Claims] 1. A step of (1) keeping the inside of the continuous mixer under reduced pressure while mixing the porous feed having a large particle diameter and the added fats and oils in a closed type continuous mixer (2) Instantaneous atmospheric pressure from the reduced pressure state A method for adding fats and oils to a porous feed, wherein each step comprising a step of opening downward is repeatedly performed sequentially. 2. The method according to claim 1, wherein the porous feed having a large particle diameter has a particle diameter of 10%.
The method for adding fats and oils to a porous feed according to claim 1, which is not less than mm. 3. The method according to claim 1, wherein said reduced pressure is -5 with respect to atmospheric pressure.
The method for adding fats and oils to a porous feed according to claim 1 or 2, wherein the oil or fat is not more than 00 mmHg. 4. The processing time of the step of releasing to atmospheric pressure is 10
The method for adding fats and oils to a porous feed according to any one of claims 1 to 3, wherein the time is within seconds. 5. The method according to claim 1, wherein the step of releasing to atmospheric pressure is performed at least four times. 6. A closed type continuous mixer capable of continuously charging and discharging a porous feed and having an airtight means for keeping the inside airtight at the time of charging and discharging, and an air release valve provided in the continuous mixer. And a vacuum pump for degassing the air in the continuous mixer. 7. The apparatus according to claim 6, wherein the stirring device of the continuous mixer is a ribbon mixer.