FI108922B - Device for dividing wood chips into different fractions - Google Patents

Description

108922

A device for separating wood chips into different fractions

The invention relates to a device for dividing wood chips of various sizes or similar substantially hexagonal shaped pieces having length and width and substantially smaller thickness, and possibly pulverized wood chips, by separating the wood chips and the fine chips and chips fines particles, wherein the various chips and 10 fines are arranged to be separated by one or more separating walls arranged in accordance with different flight paths provided by impulse effect, the apparatus comprising a feeder for feeding and dissolving wood chips to the inclined support surface, is provided at time-15 with an impulse effect on the chips at the gap, by a continuous flow of gas, or fines particles.

Such a device is known from the Applicant's Finnish Utility Model No. 3899. Such a device is intended to distinguish between different fractions of a large amount of wood chips 20 (hundreds of cubic meters per hour) depending on the thickness of the chips. At the same time, higher densities can also be distinguished: material such as scrap and particles of indefinite shape as well as fine particles. Such separation is required in cellulose preparation aids for the treatment of the raw material.

In such a device, the plane defined by the width and length of the chips is subjected to a dynamic gas pressure (practically atmospheric pressure) for a short period of time such that the effect is constant per unit area. This produces an impulse - '! * Side effect that causes the chip to change speed as follows: force' ·:: 30 = pressure x area or F = pA, impulse = force x impact time or I = Ft and velocity change = impulse / mass = dv = l / m => dv = pAt / m. Since the mass of the chips: ,,,: depends on the volume which is thickness and area dependent 2 108922 and on the other hand the impulse depends on the area, the whole becomes independent of the width and length of the chip so the velocity change depends on the thickness dimension such that the ratio of velocity changes to 5 is inversely proportional to the ratio of thicknesses. This velocity change causes the chips to move in the direction of the thickness dimension for different lengths of travel along their length or width direction at the same speed for the same distance.

10 To achieve an impulse effect on the desired chip surface requires the chips to be oriented such that the surface is perpendicular to the direction of the dynamic pressure. To achieve a certain lifetime, the chips must move at the same speed over a point of pressure of a certain size.

15

The chips slip along a sloping plane over a certain distance, allowing them to arrange in the correct position and reach a certain speed. At this speed they slide over a narrow gap, from which the air flowing gives an impulse effect at its dynamic pressure. The chips fly freely in the airspace, where they have 20 same velocity components downwards and, according to the above calculation, the velocity dependent on the thickness [·· '·', whereby different chips of different thickness fly differently: "at distance from impulse effect: .

25 High density scrap particles (eg steel has a density of about ten times the solid density of the wood) get very little change in velocity as well as vaguely shaped particles with aerodynamic properties !!! because of. In this way, these particles are removed from the chips stream by the same treatment. Correspondingly, the fine dust particles receive a high velocity '30 change with a very small thickness dimension. This effectively separates the dust into its own current.

3, 108922

Different fractions are collected from the separated chip stream by placing the separating walls at appropriate locations. The separating walls can be adjustable so that the chips content of the fractions can be changed as needed. In addition, re-separation for the desired fraction can be performed by the same method.

Compared to other known devices, such a device is more maintenance-free as there are far fewer moving parts. Mechanical durability is also better with the entire device due to the low fatigue load, especially since there is no need to perform 10 reciprocal or gyroscopic movements. The adjustability of the device can be made easier and faster compared to the present ones.

It is an object of the invention to provide such a device initially, which provides a simple and reliable means of redirecting wood chips that have already been broken down or not yet broken into the chip among the accepted chips (accept) in the device and thus prevent the device process from being speeded up.

This object is solved in accordance with the invention and the device according to the invention is characterized in that it comprises wood chips distributed by the device. A transmitting force-acting component and a guide surface arranged therewith dimensioned such that the wood chips are partially or completely guided past the component over the component by a sliding surface formed by the wood formed in the event of a malfunction and by said guide surface.

In a preferred embodiment of the invention, the at least two devices are arranged in a sequence such that the wood chips to be processed; '' 30 is arranged to move under gravity to pass through the devices between: '' the indivisible wood chips transferring power component :: and / or the split wood chips transferring power components.

j 4 108922

In yet another preferred embodiment of the invention, it is arranged that the fraction of chips (reject), which is over-thickened in the direction of travel of the wood chips, is arranged by gravity to drop to the feeder of the next device.

In yet another preferred embodiment of the invention, the inlet side of the feeder of said next device is dimensioned such that in the event of an overload or malfunction, the fraction of chips (reject) disaggregated by the device above in the forward direction of the wood chips is ).

In yet another preferred embodiment of the invention, it is provided that: 15, to the last of said at least two devices in the direction of travel of the wood chips is provided with a conveyor for removing over-thick chips (reject) from the device having a conveyor inlet dimensioned such that the reject is gravitationally displaced to a plurality of accepted chips.

20 ';: ·' The invention will be described in more detail below with reference to the accompanying drawing, in which:

Figure 1 shows a schematic sectional view of the device according to the invention.

25

Figure 1 shows schematically an apparatus for dividing wood chips 1 into different fractions. Any fines 13 in the wood chips 1 are separated. · 'As its own fraction and chips pieces 11,12 by thickness into chips, pieces 11 (reject) and approved chips 12 (accept).

30: The apparatus comprises a feeding device 6 for feeding wood chips 1 to the supporting support surface 2 in substantially one layer. The individual chips pieces 11,12 naturally rest on their largest surface, i.e., in the case of chips, on their support surface 2, in the case of chips.

The supporting surface 2 is a rigid, flat and wear-resistant planar surface which forms a 5 slanting slope on the splitting wood chips 1.

The wood chips 1 from the feeder 6 are arranged to slide first on the inclined support surface 2 and thereafter over the support surface 3, the gap being arranged to be applied to one or more chips 11,12 or fines particle 13 at the respective position facing away from said support surface 2. The impulse effect is arranged to be provided by a gas flow 4, preferably by an air flow. The direction of the impulse effect 4 may be perpendicular to the support surface 2 or also at an oblique angle to the support surface 2.

15

The air flow is produced by the fan 7. A nozzle chamber 8 is provided between the fan 7 and the slot 3 to ensure uniform impulse action 4.

Chips of different thicknesses 11, 12 and possible fines particles 13 are arranged to be separated from each other according to the different paths given by the impulse effect 4 to the particles to be divided.

• ·

The fines particles 13, which are smaller than the width of the gap 3, receive the greatest velocity change, whereby they are arranged to be guided by the adjusting, ···. 25 / by the action of the baffle 14 into its own fraction in the trough 15.

* ·. · · ·, Chip pieces 11, 12 which are significantly larger than the width of the slot 3. · · ·. and thus heavier than said fines particles 13, have a substantially smaller velocity change at the slit 3 relative to fines particles 13. The impulse given by the pressure flies the chips 11, 12 into different trajectories * t ':' according to the chip thickness and the chips stream is divided into different fractions by means of a separating wall 5 6 108922. On average, the thinnest chips 12 fly over the separation wall 5 and are further guided to the discharge screw 10. Correspondingly, the thicker chips fly a shorter distance and fall into the feeder 6 'between the separation wall 5 and the gap 3.

5

The average thickest chips 11 entering the feeder 6 'are reprocessed in the second device below in the drawing example, whereby some of them (the lightest part) pass over the separating wall 5' to the unloading screw 10 and part (average heavier part) falls between the separating wall 5 '10 and slot 3 in a trough with a discharge screw 9.

The treatment of wood chips 1 is arranged in its entirety to take place in a dust-tight treatment chamber 17. The air is removed from the chamber 17 by reference 34 meaning through an opening.

15

In the embodiment of FIG.

The chips from the hopper feeder 6 'are further separated by a gas flow 4 from the nozzle chamber 8' t, whereby again the chips 11 defined as overpacked by the flight path fall on the unloading screw 9 and the approved chips 12 fly over the separation wall 5 'and fall 10 on.

> ». · ·. For example, in the event of a possible malfunction of the tray feeder 6 ', the entire device need not be stopped immediately, a guide surface 30 provided adjacent to the tray feeder 6', along which the excess chips 11 accumulated on the tray feeder 6 'begin to slide over the tray feeder 6'. sufficient wood chip to form a sliding surface 33.

7108922

Instead of a separate guide surface 30, the upper surface 32 of the separation wall 5 may provide the necessary guide surface for guiding all chips in the event of a malfunction on the discharge screw 10.

Similarly, in the event of a malfunction of the discharge screw 9, all chips are arranged to slide as the discharge screw 9 fills along the guide surface 31 or, alternatively, along the upper surface 32 of the separation wall 5 'over the discharge screw 10.

• · <t * · * * * -: t '· * * · i · • »

Claims (5)

Apparatus for making kinds of various large chip pieces (11, 12) or corresponding substantially hexaediform pieces of length and width and thickness substantially smaller than these, and possibly particle particles (13) containing wood chips (1) by means of impulse action, separating from the wood chips (1) into their own fraction the thick chips (11) or the fine particles (13) or bathing the thick chips (11) and the fine particles (13), the various chips (11, 12) and the fine particles (13) being arranged one separated from each other according to different pulses arranged by means of impulse, arranged one or more separation walls (5, 5 '), which device has a feeding device (6, 6') for feeding wood chips (1) on a sloping supporting surface (2) and sliding on said support surface (2) across a transverse gap (3), through which a pulse action has been arranged to be effected by means of a continuous gas stream (4) on chip pieces (11, 12) or particle particles (13) at the gap (3), characterized in that the device comprises a power-driven component (6 ', 9) which moves by means of the device sorted wood chips (1). ) and a bearing surface (30, 31, 32) which is so dimensioned that wood chips (1) are partially or wholly passed by said component (6 ', 9). . By means of the sliding surface (33) formed by the wood chip (33) assembled on the component during its disturbance position, and said joint surface (30, 31, 32) under the influence of the ··· ···. of gravity. • · · Device according to claim 1, characterized in that at least two devices are provided *: **; Are arranged one after the other so that the wood chips (1) to be treated are arranged to be displaced through the devices under the influence of gravity. ·. transmitting power-driven components (6) of associated unsorted wood chips • »·, · · ·. and / or sorted wood chips (1) transmitting power-driven components (6 ', 9). • · 3. Device according to claim 2, characterized in that the fraction (11) (reject) of the wood chip (1) in the direction of transport in the front direction of the wood chip (1) is arranged to fall down under the influence of gravity. in the following device's feeding device (6 '). 4. Device according to claim 2, characterized in that the inlet side (6 ') of the following device's feed device (6') is so dimensioned that, in an overload or disturbance position, the fraction (11) of the chips (11) sorted in the direction of transport of the device (1) ( rejects) are arranged to be transferred to the group of accepted chips (12) (accept) under the influence of gravity. 10 5. Device according to claim 2, characterized in that, of the at least two devices, a conveyor (9) for separating the over-thick chip pieces (11) (reject) from the device is subsequently arranged in the direction of transport of the wood chips (1). the inlet side of the conveyor (9) is dimensioned such that, in an overload or disturbance position, the reject (11) is arranged to be moved under the influence of gravity to the group of accepted chip pieces (12) (accept). * · · • · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·