JP2003094009A - Treating equipment of food waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively remove foreign substances contained in food waste in equipment for converting the food waste produced at a catering facility, a hotel a convenience store, a dining room a restaurant, and the like, into a livestock feed and a fertilizer for plants. SOLUTION: This treating equipment of the food waste comprises a receiving hopper for receiving the food waste, a self-cleaning double-screw extruder for extruding the food waste fed from the receiving hopper to an exit while grinding it, a dryer for drying the food waste treated with the double-screw extruder, and a sifting device for screen classifying the dried food waste in this order. It is desirable to install a crusher for cutting and crushing the food waste between the hopper and the double-screw extruder or a gravity classifier at the back of the sifting device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for converting food waste generated in a lunch facility, a hotel, a convenience store, a cafeteria, a restaurant, etc. into a feed for livestock and a fertilizer for plants. The present invention relates to a food waste processing apparatus capable of removing foreign matter contained in an object.

[0002]

2. Description of the Related Art Food waste generally has a high water content and various foreign substances such as chopsticks, toothpicks, vinyl wrap, plastic trays, metal pieces such as spoons and beer bottle stoppers, and pebbles. Contains. For this reason,
In order to effectively use it as feed, fertilizer, etc., a drying process of food waste and a removal process of foreign substances contained therein are required.

In the above-mentioned drying step, it is desirable to make the food waste as fine as possible in order to improve the drying efficiency, and in removing the foreign matter, the organic waste is dried to reduce the adhesion to the foreign matter. It is desirable to start from.

As a conventional technique relating to the treatment of such food waste, for example, there is one described in JP-A-11-156332. This is to dry the food waste by utilizing the heat of fermentation, and the storage tank into which the food waste is put, the heater for heating the inside of the storage tank, and the food waste in the storage tank. It is provided with a rotary blade that stirs while stirring and a sieve that separates foreign substances from the fermentation-processed food waste. In this device, the food waste is put into the storage tank, and the food waste is crushed and stirred by the rotating blades. Also, the heater heats the inside of the storage tank to evaporate the water from the organic waste. Then, the organic waste and the foreign matter dried by the evaporation of water are separated by a sieve to separate them.

As another conventional technique, Japanese Patent Laid-Open No. 2000-2000
-41588. This one is
A first container for disassembling the food waste (leftover food etc.) into pieces and a second container for drying the food waste are provided, and an outlet of each of these containers is connected to a wind power sorter.
In addition, a stirring blade (rotating body) is provided in each of the containers, and the rotating shaft thereof is hollow, and steam can be supplied into the containers from the hollow portion. In this device, leftover food or the like is put into a first container, and saturated steam is supplied from a hollow rotating shaft. Condensation occurs when the saturated steam enters the first container, and the condensed water stirs the lumpy leftover rice to separate it. It should be noted that saturated steam is said not to dissolve mixed plastic trays and the like.

[0006] The leftover food and the foreign matter thus separated are put into a second container after the foreign matter such as film and paper is removed by the first air sorter. In the second container, heated steam is supplied from the hollow rotating shaft to dry the leftover rice. Further, it is said that foreign matters such as trays are removed and chopsticks and the like are appropriately removed by the following wind power sorter.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the technique described in Japanese Patent No. 6332, the food waste is crushed and stirred in the storage tank, but if the food waste is crushed finely, the foreign matter can be crushed finely even though the foreign matter can be efficiently dried. Therefore, the foreign matter cannot be separated as a sieve product in the subsequent sieving process. On the contrary, if it is not crushed too much, it will not only be difficult to dry food waste in a short time because of large lumps such as cabbage and meat that is not easily crushed, but these will be sieved in the subsequent sieving process. Since it is separated as a fine substance and removed as a foreign substance, it is not preferable in terms of effective use of resources.

Further, the technique disclosed in the above-mentioned Japanese Patent Laid-Open No. 2000-41588 is mainly intended to treat the leftover food and is not provided with a crushing device. Therefore, foreign matters such as films, trays and chopsticks are damaged by the stirrer. It is not crushed into small pieces just by receiving it. Therefore, it is considered that foreign matter having a small specific gravity such as a film and a tray can be efficiently removed by the airflow classifier, but since the chopsticks have a relatively large specific gravity, it cannot be removed by the airflow classifier. Further, this technique has a problem that it is difficult to dry large food waste such as meat and cabbage in a short time.

As can be seen from the above description, in order to efficiently treat food waste, only organic waste in food waste is finely divided, and foreign matter is not finely divided.
A seemingly contradictory treatment method is desired. Therefore, the present invention reduces only the organic waste among the food waste,
An object of the present invention is to provide a processing device that does not make foreign matter too fine.

[0010]

In order to solve the above problems, the present invention employs the following configurations. That is,
The food waste processing apparatus according to the present invention is a self-cleaning twin-screw that receives a food waste and a receiving hopper that sends the food waste supplied from the receiving hopper to the outlet side while crushing it and pushes it from the outlet. It is characterized in that a screw extruder, a drying device for drying the food waste processed by the twin-screw extruder, and a sieving device for sieving the dried food waste are sequentially provided.

In this processing apparatus, the food waste put in the receiving hopper is supplied to the twin-screw screw extruder, sent to the outlet side while being crushed by the twin-screw extruder, and extruded from the outlet. . The extruded food waste is dried by a drying device, and then foreign substances are sieved by a sieving device to take out organic waste. Since the twin-screw extruder is a self-cleaning type device, food waste attached to the rotary blades is removed.
If a crusher for cutting and crushing food waste is provided between the receiving hopper and the twin-screw extruder,
The crushing by the twin-screw extruder is efficiently performed. Further, it is preferable to provide a specific gravity difference sorter on the rear side of the sieving device because small foreign matters such as pebbles and metal pieces can be effectively removed.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below. FIG. 1 is a block diagram showing an apparatus for treating food waste according to the present invention. In this apparatus, a rotary crusher 2 as a crusher is provided on the outlet side of a hopper 1 for introducing food waste. A self-cleaning twin-screw extruder 3, a drying device 4, and a sieving device 6 are sequentially provided on the rear side thereof.

Inside the hopper 1, there are 20 openings at the top.
A 0 mm coarse screen 11 is provided at the bottom with a screw conveyor 12 for sending food waste to the next step, and the bottom surface of the hopper 1 and the lower surface of the screw conveyor 12 have a specific gravity of metal or stone. A space serving as a settling section 13 for settling large foreign matters is provided. Also, hopper 1
A collection box 14 for collecting coarse materials that cannot pass through the coarse screen is provided next to the.

The rotary crusher 2 has a casing 21 in which a pair of rotary shafts 22 are horizontally mounted.
The rotary blade 23 attached to the
Cut to a width of about 100 mm.

The casing 31 of the twin-screw extruder 3
As shown in FIG. 2, a kneading chamber 32 having a cocoon-shaped cross section is provided inside, and an input port 33 is provided at the upper end of one end and a discharge port 34 is provided at the lower end of the other end. . Two rotary shafts 35, 35 are laterally installed in the casing 31, and a large number of screw paddles 36 are externally fitted to the rotary shaft 35. The screw paddle 36 has a convex lens-shaped cross section orthogonal to the rotation axis and is gradually twisted in the axial direction.

The tip of the convex lens-shaped screw paddle 36 moves while maintaining a minute distance from the wall surface of the kneading chamber 32 and the screw paddle 36 of the adjacent rotary shaft 35, and food waste attached to these is scraped off. . That is, this twin-screw extruder is a self-cleaning type extruder having a self-cleaning action. The paddle used in the present invention is only the screw paddle 36 having a spiral surface in contact with the kneaded material, and it is desirable not to use the flat paddle as shown in FIG.

The casing 41 of the drying device 4 is provided with an inlet 42 at an upper portion on one end side, an outlet 43 at a lower portion on the other end side, and a gas outlet 4 above the outlet 43.
7 are provided, and a stirring blade 44 is provided in the casing 41. Also, casing 4
1 is covered with a jacket 45, a rotary shaft 46 to which the stirring blades 44 are attached is hollow, and a heat medium such as steam is introduced into the hollow portions of the jacket 45 and the rotary shaft 46.

Further, the sieve device 6 has an opening of 10 mm.
Screen 61 and first outlet 62 for discharging the sieved material
And a second discharge port 63 for discharging the substance under the sieve.

When using this food waste processing apparatus, the collected food waste is put into the hopper 1. In this case, it is desirable to remove foreign substances that are easy to remove, such as a bento box case whose expiration date has expired, and to insert the foreign matter in advance. Since the hopper 1 is provided with a coarse screen (lattice) with an opening of 200 mm, the plastic bag containing the food waste, the mixed string, a part of the cooking gloves, etc. are placed on this screen. Get caught. These are appropriately removed and placed in the collection box 14. Since the openings are large, meat, cabbage and the like fall into the hopper 1.

The dropped food waste is sent to a crusher (rotary crusher) 2 by a screw conveyor 12.
In addition, since metal such as spoons and pebbles have a large specific gravity,
It sinks into the settling section 13 provided below the screw conveyor 12.

In the rotary crusher 2, the rotary blade 23 cuts food waste into a width of about 50 to 100 mm. This cutting is preferably as large as possible, but if it is made too large, it will not be possible to bite the screw paddle 36 in the twin-screw extruder 3 in the subsequent stage. Therefore, determine the cutting width with the outer diameter of the screw paddle 36 as a guide. deep.

The twin screw extruder 3 in the next step is
It is a self-cleaning type device that has a crushing action on food waste. As shown in FIG. 6, a general twin-screw extruder has a flat plate S spirally attached to a rotary shaft J to form a feed blade, and the material is fed forward while rotating. At this time, since the material is divided by the feed blade of the other rotating shaft, the material is subjected to some kneading action, but is not subjected to crushing action.

FIG. 5 shows a self-cleaning type twin-screw kneader, which is a stirring blade F called a flat paddle.
Is fitted onto the rotating shaft. Since these flat paddles are arranged side by side in front and back, the front and rear paddles create a state in which they are partitioned by a right-angled wall, and when the pair of left and right flat paddles rotate, the material is the gap between the tip of the paddle and casing C. Is forced to pass through, and the material is crushed finely by the compression and stretching action at that time. Since the flat paddle F itself has a poor ability to feed the material, a screw paddle (not shown) for feeding the material forward is provided near the material supply port of the kneading machine. Since the front and rear flat paddles are externally fitted to the rotating shaft while changing the phase, the material undergoes shearing action by the vertical plane of the flat paddle as it advances.

2 and 4 show a twin-screw extruder used in the present invention, in which the screw paddle 36 is provided on the rotary shaft.
Only is fitted out. Although this screw paddle is not the same as the flat paddle, it can pass through the gap between the tip of the paddle and the casing, and the material can be finely crushed by the compression and stretching action at that time. On the other hand, vinyls (bags, gloves, etc.) are stretched as they are and are not crushed. In addition, foreign matter such as chopsticks and coarse bones of fish cannot pass through the gap and are transferred forward by the screw surface of the paddle.

It is considered that the screw paddle has a larger occupied volume in the casing as compared with the screw paddles shown in FIGS. 5 and 6, which also contributes to the crushing action. In addition, unlike the flat paddle, the vertical surface of the screw paddle is not exposed, so that the vertical surface does not shear and crush foreign materials such as vinyl, chopsticks, and coarse bone. That is, according to this extruder, only organic waste is finely crushed.

When the material was actually crushed with this twin-screw extruder, organic waste such as leftover foods, vegetables, and meat was crushed to a few mm or less, and the vinyls were discharged in their original form without being crushed. Plastics such as lunch boxes and chopsticks are crushed a little, but larger than organic waste (several mm to 5 mm).
0 mm), and the bone of the fish was about several mm to 50 mm. Also, the bones of the bird were crushed because they had a hollow structure and were brittle.

The food waste crushed in this way is sent to the drying device 4 and input from the input port 42. The food waste introduced from the introduction port 42 is transferred toward the discharge port 43 while being stirred by the stirring blade 44. A heat medium such as water vapor is introduced into the jacket 45 of the drying device 4 and the hollow portion of the rotating shaft, and since the organic waste in the food waste is finely crushed, the drying is efficiently performed. . The water in the organic waste is evaporated and discharged from the gas outlet 47, and the dried food waste from which the water has been removed is discharged from the discharge port 43.

As described above, since the organic waste is crushed by the twin screw extruder 3, the drying device 4 is used.
When it is dried in, it is discharged as granular material of about 5 mm or less. On the other hand, foreign matter is not so much crushed, so it is discharged in a state larger than organic waste.

The food waste whose water content is reduced by the above-mentioned drying is sent to the sieving device 6 and separated into an under-sieved product that passes through the screen 61 and an over-sifted product that does not pass through it. Most of the sieve material is foreign matter or bone, and is discharged from the first discharge port 62 and discarded. Further, the sieved substance is almost organic waste and is discharged from the second discharge port 63.

When it is desired to further remove foreign matter such as toothpicks, pebbles, and sand from the above-mentioned sieve product, this sieve product may be sent to a specific gravity difference sorter 8 using both wind force and vibration for processing. In this specific gravity difference sorter, the inside of the casing is partitioned into upper and lower parts by an inclined porous plate 82, and the lower part thereof is a wind box into which air from the blower 81 is introduced. The collected matter is dropped from the supply pipe 83 onto the perforated plate 82,
It receives buoyancy due to the rising airflow passing through 2. Then, on the perforated plate 82, it is separated into an upper layer made of a lightweight material having a small specific gravity and a lower layer made of a heavy material having a large specific gravity.

Since the perforated plate 82 is vibrating, the heavy object is greatly affected by the vibration, and rises against the inclination of the perforated plate. On the other hand, since the lightweight object is not much affected by the vibration, it descends along the inclination of the perforated plate. Then, heavy objects (pebbles, toothpicks, etc.) are discharged from the upper end of the inclined perforated plate, and organic materials that are lightweight are discharged from the lower end of the inclined perforated plate. Even if a small piece such as a plastic sheet is mixed, it is discharged from the air outlet 84 together with the ascending airflow and collected by the cyclone 85.

A fermentation device can also be used as the above-mentioned drying device. In this case, if the water content is too high, the treatment capacity decreases. Therefore, it is preferable to perform a treatment after mixing a part of the sieved product in the sieve device 6 with the discharge of the twin-screw extruder 3. Also, the water content of the fermented organic waste is
Since it is usually about 30 to 40%, in order to enable long-term storage, a secondary drying device is provided as a post-step of the sieving device,
It is desirable to reduce the water content to about 15 to 20%.

[0033]

As described above, the apparatus for treating food waste according to the present invention makes only the organic waste in the food waste fine, and the foreign matter is separated and dried without making it too fine. It has become possible to efficiently recover organic waste in food waste.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a processing apparatus of the present invention.

FIG. 2 is a partial sectional plan view (a) of the twin-screw extruder and a view (b) taken along the line AA.

FIG. 3 is a perspective view of a screw paddle (a) and a flat paddle (b).

FIG. 4 is a vertical sectional view (a) and a horizontal sectional view (b) showing a main part of a screw extruder using a screw paddle.

FIG. 5 is a vertical sectional view (a) and a horizontal sectional view (b) showing a main part of a screw extruder using a flat paddle.

FIG. 6 is a vertical sectional view (a) and a horizontal sectional view (b) showing a main part of a screw extruder using a spiral blade.

[Explanation of symbols]

1 hopper 2 rotary crusher 3 twin screw extruder 4 drying equipment 6 Sieve device 8 Specific gravity difference sorter 11 coarse screen 12 Screw conveyor 13 Subsidence 14 collection boxes 23 rotary blades 32 kneading room 35 rotation axis 36 Screw Paddle 44 Stirring blade 45 jacket 61 screen 82 inclined perforated plate

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B07B 9/00 C05F 5/00 13/11 9/02 E B09B 5/00 17/02 C05F 5/00 F26B 9/06 Q 9/02 11/14 17/02 B09B 3/00 303M F26B 9/06 ZAB 11/14 5/00 Z (72) Inventor Koji Mizuta 1-12-19 Kitahorie, Nishi-ku, Osaka City, Osaka Prefecture F-Term in Kurimoto Ironworks Co., Ltd. (reference) 3L113 AA07 AB02 AC05 AC08 AC40 AC58 AC59 AC67 BA39 DA01 4D004 AA03 AA04 BA04 CA01 CA08 CA12 CA15 CA42 CB13 CB16 CB28 CB31 CB45 4D021 A01 01 NA01 NA02 NA06 NA09 4G078 AB20 BA01 BA07 DA09 EA05 4H061 AA03 CC32 CC42 CC55 GG19 GG52 GG67 GG70

Claims (3)

[Claims] 1. A receiving hopper for receiving food waste,
A self-cleaning twin-screw extruder that crushes the food waste supplied from the receiving hopper, sends it to the outlet side and pushes it out from the outlet, and dry the food waste processed by the twin-screw extruder. An apparatus for treating food waste, comprising a drying device and a sieving device for sieving the dried food waste in order. 2. The food waste processing apparatus according to claim 1, wherein a crusher for cutting and crushing food waste is provided between the receiving hopper and the twin-screw extruder. 3. The food waste treatment device according to claim 1, wherein a specific gravity difference sorter is provided behind the sieve device.