JPS5831988B2 - Classifier for wood chips contaminated with foreign substances - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a classification device for removing foreign matter from wood chips containing foreign matter such as metal pieces and stone chips in the dry manufacturing method of fiberboard.

For wood chips, we use the ends of logs, offcuts, plywood ears, stripped cores, etc., so we use figure-8 rings driven to prevent the ends of logs from cracking, nails for assembling rafts, pieces of wire, etc. They often contain foreign objects such as metal fragments, shells like Fujibbo that stuck to logs when they were stored at sea level, and pebbles and sand that got into the skin of the logs when they were piled up on the ground.

When wood chips contaminated with such foreign substances are passed through a fibrillator to shape the wood fibers, and the fibers are hot-press plated using an adhesive to produce fiberboard,
There were drawbacks that caused various problems, such as damage to the defibrator blades, sparks that could ignite the fibers and cause explosions or fires, and damage to saw blades when processing fiberboard. .

By the way, there are two methods for producing fiberboard: a wet method and a dry method. In the former, wood chips are transported in water, so foreign substances with a large specific gravity are precipitated and removed, but in the dry method, wood chips are transported in water. Since the chips are blown by air current, in order to remove foreign objects, a metal detector can be installed during the conveyance and chips containing metal can be discarded, or iron pieces can be attracted with appropriately placed magnets along the conveyance path. However, the former has a poor chip yield, the latter cannot separate nonferrous metals, and both cannot separate nonferrous metals.
No device has yet been invented that can remove foreign matter more efficiently from wood chips contaminated with foreign matter.

Therefore, the present invention is an improvement on the above-mentioned prior art, and its purpose is to provide an apparatus for efficiently classifying wood chips mixed with foreign matter into foreign matter and wood chips.

Embodiments of the present invention illustrated in the drawings will be described below.

(1) First, wood chips contaminated with foreign matter are conveyed in appropriate amounts from the wood chip silo by a suitable supply device 3 such as a screw conveyor or a belt conveyor, and enter the vertical classification chamber 1 from the chip population 22.

The body of the vertical classification chamber 1 has a vertically elongated shape with a constant width, and a large foreign matter discharge port/air intake port 4 at the lower end is tapered into a funnel shape.

Air is sucked into the fan 10 and introduced from the air intake port 4 at the lower end.

This introduced air causes air resistance/
Pieces of stone, iron, etc. with particularly low weight values fall downwards, but wood chips with high air resistance/weight values, etc.
Fine metal pieces, wood chips with iron pieces, thin aluminum pieces, etc. are blown upwards by adjusting the suction power of the fan 10 and the inner diameter and length of the vertical classification chamber. It is now adjusted by

To give one specific example, the wind speed is ■ in the narrow part at the bottom of the vertical classification chamber, that is, near the air intake port 4.

-25~30? ? ? /sec, wind speed V near the top
,=18~20? ? A wind speed of Z/sec is desirable.

In this case■.

is about 50 taels larger than ■1, so the wind force of ■o blows small foreign objects, wood chips, etc. upwards, but iron pieces,
Only large foreign objects such as stones fall and are stored in the foreign object storage chamber 12, and are discharged by the carrying out device 15 as required.

(2) On the other hand, wood chips with high air resistance/weight values, fine metal pieces, iron pieces, etc. that are blown upward are bent in the g-right angle direction from the upper end of the vertical classification chamber 1. The air is blown in the direction of air flow through the horizontal classification chamber 2, which is elongated in the horizontal direction.

At this time, it is desirable that the wind speed 2 is adjusted to approximately 12 to 20 m/sec.

At this time, wood chips from wood species that are dry or have a low specific gravity ride on the airflow in the horizontal classification chamber 2 and go straight to the cyclone 21. Since the air resistance/weight value of biting chips and the like is small, they fall onto the multi-stage flapper 7 on the bottom of the horizontal classification chamber 2.

Along this flapper 7, small foreign matter collection chambers 8.8', 8'' are provided on the underside of the flapper 7.

8,8'. 8〃Small foreign matter falling port/air suction port 5゜5/, 5// damper 6.6', 6" at the lower end
By adjusting the suction amount of air, the wind speed V'4.V'4.v''4 in the recovery chamber 8°8', 8'' is adjusted.

Normal V4, V'4, V″4 = 5-10m
/sec is preferable.

Chips with a high moisture content are blown back into the horizontal classification chamber 2 by the rising air currents with wind speeds of V4, V/4, and V/'4, but chips with high moisture content are blown back into the horizontal classification chamber 2, but small metal pieces, chips with bits of stone, aluminum pieces, etc. The particles fall along the slope of the flapper 7, pass through the small foreign matter discharge port/classification air suction port 5°5', 5" at the bottom of the collection chamber 8, 8', 8", and enter the small foreign matter storage chamber 1.
3, 13'.

It is accommodated in 13".

At the bottom of these small foreign matter storage chambers 13, 13', 13'', conveying devices 17, 1 such as belt conveyors, screw conveyors, etc.
7' and 17" are provided.

Furthermore, there is a risk that foreign matter or wood chips may accumulate on the upper surface of the flapper 7, or foreign matter or wood chips may become clogged between the flappers 7, which may impede the separation of foreign matter and chips. To prevent this, a flapper top surface cleaning device 14 such as a wire brush or picker roll is installed.

(3) The wood chips that do not contain foreign substances and are thus classified in the horizontal classification chamber 2 are led to the chip collection chamber 9 connected to the end of the horizontal classification chamber 2 in the air flow direction.

Note that it is desirable that the air velocity (3) in the portion of the horizontal classification chamber 2 near the chip collection chamber 9 be set to be somewhat smaller than or equal to the wind velocity (2).

The chip collection chamber 9 consists of a cyclone 21 and a rotary valve 20 for discharging wood chips, and fine powder is introduced into a fine powder conduit 18 connected to the upper part of the chip collection chamber 9, and the fine powder is discharged.

The classification airflow generating fan 10 for sucking the fine powder into the fine powder conduit 18 is provided as described above.

The wood chips discharged as a product from the rotary valve 20 are used in a digester that steams the wood chips in appropriate amounts.
is supplied by the conveying device 16.

As the conveyance device 16, a belt conveyor or a screw conveyor is used.

(4) By the way, it is better to provide a plurality of small foreign matter recovery chambers 8, 8', 8 formed on the lower surface of the horizontal classification chamber 2.

This is because the dampers in each room are 6.6'. This is because the adjustment of 6" can precisely respond to the difference in specific gravity and air resistance/weight between chips and foreign matter for each chamber, making classification of foreign matter and chips more efficient.

Since the present invention has the above-described configuration, its effects can be summarized as follows.

■ The present invention separates foreign objects and wood chips using airflow and then supplies the wood chips to the defibrator, so foreign objects do not get mixed into the wood chips and damage to the defibrator blades and fires are prevented. can.

In particular, it has a great advantage in increasing the safety of the dry fiberboard manufacturing method.

■ After large foreign objects are removed in the vertical classification chamber 1, small foreign objects are removed in the horizontal classification chamber 2, so classification is performed in stages.
Classification efficiency is good.

(2) Wind speeds Vo, V in the classification chambers 1 and 2.

V2. By decreasing the speed in the order of V3, it is possible to improve the efficiency of classifying small foreign objects in particular.

(2) By providing a plurality of small foreign matter collection chambers 8, 8' and 8' in parallel, the classification efficiency of small foreign matter can be significantly increased.

[Brief explanation of the drawing]

The drawing is a skeleton sectional view of the device of the present invention. 1...Vertical classification chamber, 2...Horizontal classification chamber, 3...Chip supply device, 4...Large foreign matter outlet/air intake port, 5 ,5',5"...
・・Small foreign matter exhaust port and air intake port, 6.6', 6″・・
...Damper, 7...Flapper, 8.8
'8"...Small foreign object collection room, 9...
...Chip collection room, 10...Fan, 11...
...Chip storage chamber, 12...Large foreign object storage chamber, 13゜13'13''...Small foreign object storage chamber,
14... Flapper top surface cleaning device, 15...
. . . Large foreign matter removal device, 16 . . . Wood chip removal device, 17, 17'. 17''...Small foreign object removal device, 18...
- Fine powder discharge conduit, 19... Input port for chips containing foreign matter, 20... Rotary valve, 21
...Cyclone, 22...Chip entrance.

Claims (1)

[Claims] 1. A vertical classification chamber 1 having a large foreign matter discharge port/air intake port 4 at the lower end and a chip population 22 at the side wall is provided, and a horizontal classification chamber 2 is connected to the upper end of the vertical classification chamber 1, On the bottom surface of the horizontal classification chamber 2, multi-stage flappers 7 with flapper cleaning rolls 14 are arranged in parallel at right angles to the axis of the horizontal classification chamber 2, and on the bottom surface of the multi-stage flapper 7, a small foreign matter collection chamber 8 is provided. This apparatus for classifying wood chips mixed with foreign matter is characterized in that the classification chamber 2 is connected to a cyclone 21 having a fine powder discharge conduit 18 inserted into its head, and a chip storage chamber 11 is provided at the lower part of the cyclone 21. 2 Dampers 5, 5' are provided at the lower end of the small foreign matter collection chamber 8 to adjust the amount of air introduced into the collection chamber 8. Wood chip classification equipment. 3. The apparatus for classifying wood chips contaminated with foreign matter as set forth in claim 1, paragraph 2, wherein a plurality of small foreign matter collection chambers 8 are provided in parallel. 4 The air velocity in the classification chamber is the velocity at the bottom of vertical classification chamber 1■
. , the speed v1 of the central portion, the speed (2) of the horizontal classification chamber 2 closer to the vertical classification chamber, and the speed V3 of the portion closer to the same Ikron decrease in this order. A classification device for wood chips contaminated with foreign matter.