SU473371A3 - Plant for the treatment of wood chips with electrons - Google Patents

Description

one

The invention is intended for use in the pulp and paper industry.

A known installation for treating wood chips with electrons, comprising an electron beam source with a spreading part forming an irradiation zone, and a device for transporting chips.

The main disadvantage of the known apparatus is that it does not provide sufficient uniformity of electron irradiation over the cross section and length of the chips.

The aim of the invention is to eliminate this drawback.

This is achieved by the fact that the device for transporting chips is made in the form of a pneumotransport system, including a supply pipeline, which passes into the pipeline in the chip irradiation zone, the side walls of which coincide with the effective side edges of the electron beam, and its longitudinal axis is aligned with the electron beam. ; the pipeline in the irradiation zone is made of trapezoidal section and enclosed in a casing, the walls of which form a cooling chamber with the walls of the pipeline.

FIG. 1 shows the proposed installation, side view; in fig. 2 is a section along A-A in FIG. one; in fig. 3 shows a section along the line B – B of FIG. one.

A portion of the pipeline 1 of the winding and transport system through which the chips are transported (the supply pipeline) has a circular cross section with an average diameter of from 6 to 24 inches (1 inch 2.54-10 m). Through such tubes, wood chips are transported in a stream of air at a speed of about 6000 feet per minute. The proposed transport system is provided with a transepeal section 2 section of said pipe 1. At the ends of section 2 transitions 3 are provided for communication with pipe 1. Section 2 has a preferred length of about 6 feet.

The invention provides means for irradiating the chips with a high-energy electron beam. Such means comprise a source 4 of a high energy electron beam that is capable of producing a narrow beam of electrons, whose energy is in the order of several hundred thousand volts. A Van de Graaf generator or some other appropriate tin generator may be used.

The electron beam generated by source 4 is directed downwards into the sweep

device o, which is provided with the CTBaiMH medium for communicating a reciprocating linear beam path to the electron beam having an axis coinciding with the axis of section 2. The frequency of the electron beam is from several hundred to several thousand hours per second. The deviation of the electron beam is carried out by nasal means of magnetic or electrostatic deflecting means. Deploying device L; contains a discharged Ka.viepy, bounded by vertical parallel walls L, / and inclined highlander walls, U. 11th etemple 10 of the sweeping ycrpoiicTUia and made of titanium or other material with low resistance to the passage of electrons through it, but having resistance to heat caused by bombarding electrons.

The upper wall 11 of section 2 is made of titanium or other electron-permeable material. A vacuum is created between the walls 10 and 11 in order to provide minimal resistance to the passage of electrons through it, as well as to provide additional protection for the discharge zone of the sweep device 5. In order to fix any damage, a signaling or switching off device may be provided in the wall 11 which responds to the loss of vacuum in chamber 12 in the event of damage and protects the wall 10 from damage (device not shown). After exiting the sweep device 5, the electron beam, due to the repulsive forces existing between the electrons and due to electron scattering, resulting from the collision of electrons with air molecules, forms a diverging beam.

The trapezoidal configuration of section 2 is selected so that the side walls 13, 14 almost coincide with the side edge of the electron beam, so that the beam covers the entire width of section 2. As it passes 6 feet (1 foot 0.305 m) roll over about the brush once at a speed of transporting air around

6000 feet per minute.

During the passage of the flux, section 2, due to the high oscillation frequency of the electron beam, the chips will be repeatedly subjected to the action of the beam, as a result of which all surfaces of the elements of the flow of chips will be bombarded by electrons. The radiation intensity is selected so that at an appropriate speed of movement of the chip flow and at an appropriate speed of changing the position of the chip elements during the passage of section 2, all the surfaces of the chip flow elements would irradiate to about 0.2-0.5 Mrad.

For the purpose of irradiating all surfaces of the chips notok with the required dose without disturbing the operation of the pneumatic transport or reducing the speed of the transporting

air, it is necessary that the flow of scheny through the beam passes along its axis of the sweep. On the other hand, if the irradiation was carried out while the flux passed through the beam along the perpendicular axis of the beam sweep, in order to irradiate the position of the bird in a large dose, it is necessary to get 2 Tais. .

Section 2 is inside the casing 15. Between the casing wall and section 2 there is a chamber 16, through which, in order to prevent overheating of section 2 as a result of electron bombardment, it can circulate

water or other coolant.

In view of the fact that the elements of the mass, as they pass through section 2, are turned over several times and separated from each other, all surfaces of these elements are subjected to

uniform irradiation with electrons, and when the mnnomnnom state is scattered in section 2, the source 4 with a much lower power is required for the indicated irradiation, which is the case when processing is scaled on a conveyor belt.

It was found that, as a result of the electron bombardment, the chip storage period was significantly increased, and during this period of storage, the discoloration of the foam decreased significantly, the mass yield from the chip increased, the quality of this mass improved, its strength increased, and the lignin content increased.

PRED. M e T inventions

Claims (3)

1. An installation for treating wood chips with electrons, including an electrical beam source with an unrolled, part, about disintegrating the irradiation zone 5 and the device for transporting, about i and h with the fact that, with the use of homogeneous electron irradiation over the cross section and length of the chips, the device for the transfer of chips It is made in the form of a pneumatic transport system that includes a supply pipeline, which passes into the pipeline in the chip irradiation unit, whose side walls coincide with the effective side edges of the electron beam, and its longitudinal axis is aligned with the axis of the linear trajectory of the electron beam. 2. Installation in accordance with claim 1, which means that the pipeline in the irradiation zone is made of trapezoidal section. 3. Installation according to claim 1, characterized in that the pipeline is enclosed in the walls of which form a cooling chamber with the walls of the pipeline. / J / 52  / Ij fi A-A fPus 7