SU1467119A1 - Method of producing thermomechanical wooden pulp - Google Patents

Description

314

; Vuyu mill hot grinding the first stage of grinding.

The grinding of chips is carried out at a mass concentration of 30–40% for absolutely dry (a.c,) substance and a material output of 130–140 ° C, once fibrous into separate fragments (chips, matches, fiber bundles) and a degree of grinding 20-3U ° UP is blown into a cyclone to: separate steam from it and then I is fed to the reactor, where the chips are treated with: a solution of sodium sulfite with a consumption of 2-6% for 3–10 minutes at 70-: 90 ° and irradiate gag-rays with a dose of 10-30 kGy.

A: Then the chips are directed to the second grinding stage to 40-60 °. After milling the second stage, the mass is fed into a mixed basin and diluted with hot water and kept in the basin; at Kosh; ent1 rsh for 1 h i at 70-80 ° C, j, after which it is sorted

cleaned and fed for thickening. Ready mass is used in the composition.

; paper or cardboard

; Example (control). Spruce wood chips are fed to a continuous steam chamber,

: where it is treated with saturated steam: at 125 - C for 3 minutes. The boiled chips are ground on a first-stage disk refiner under pressure at a concentration of 35% to the degree of: grinding,

; Then the pulp is ground; on a laboratory disk mill at a mass concentration of 20% and a temperature of 70 ° C to the degree of grinding: The specific consumption is determined

electricity for grinding. The ground mass is sorted, cleaned and thickened. From the obtained Maccju, castings with a mass of 75 g / m igre are divided / physicomechanical

properties "

Example 2, (limestone), The conditions for processing the initial chips and the sequence of operations are analogous to Example 1 о.

PRI me R 3 (known) The processing conditions of the original chips and the sequence of operations are similar to example J o However, before grinding for

9

The second stage of the chips is treated with a solution of sodium sulfite with a consumption of 10% by weight of a, c, chips.

Example 4. (known). The processing conditions of the original chips and the sequence of operations are similar to example 1, However, before grinding at the second stage, the chips are processed. sodium sulfite solution with a consumption of 5% by weight of a.s. chips for 5 minutes at 70 ° C.

Example The conditions for processing the initial chips and the sequence of operations are similar to Example 4. However, before grinding at the second stage, the chips treated with sodium sulphite are irradiated with gamma rays with a dose of 10 kGy. The data of the experiment are given in the table.

Example The conditions for processing the initial chips and the sequence of operations are similar. Example 4. However, before grinding at the second stage, the chips treated with sodium sulfite are irradiated with gamma rays with a dose of 20 kGy,

PRI me R 7. The conditions for treating the initial chips and the sequence of operations as in Example 4. However, before grinding at the second stage, the chips treated with the chemical are irradiated with a gamma ray of 30 kGy.

Apply p.8, (control). The conditions for processing the initial chips and the sequence of operations are the same as in Example 4. However, before grinding, glue is irradiated with gamma rays at a dose of 5 kGy.

PRI me R 9 (control). The conditions for processing the initial chips and the sequence of operations are similar to Example 4. However, before grinding, the chips are irradiated with gamma rays at a dose of 35 kGy.

The table shows the data of experiments 1-9.

From the data in the table, it can be seen that the proposed method, with the same consumption of sodium sulfite, makes it possible to increase the mechanical strength of thermomechanical pulp, which indicates the possibility of reducing the consumption of sodium sulfite.

Claims (1)

Invention Formula The method of obtaining thermomechanical wood pulp, including steaming wood chips with temperature and pressure, the grinding of steamed chips in two steps, the processing of chips with sodium sulfite between the grinding steps and the subsequent stages of grinding the ground mass, cleaning and thickening, in order to increase the mechanical strength of the target product, while increasing the efficiency of the process, before the second stage of grinding, treated with sodium sulfite chips are exposed to gamma rays at an irradiation dose of 10-30 kGy.