SU971965A1 - Method of treating a fibrous material - Google Patents

Description

(54) METHOD FOR PROCESSING FIBER MATERIAL

one

The invention relates to the pulp and paper industry and can be used in the manufacture of fibrous semi-finished products.

A known method of treating a fibrous material by mechanical reduction when moving it through an annular working chamber formed by internal and external working bodies, one of which is reported to oscillate by rotating an unbalanced mass 1.

This method is intended for the impregnation of chips with a solution of cooking chemicals. At steady state, the processing of wood chips fills the entire space between the working surfaces and is subjected to repeated compression with a force not exceeding the tensile strength of the treated wood in order to avoid destruction of the chips 1.

The disadvantage of this method is that the processing does not and cannot be the separation of the material being processed into fibers, but only repeated crimping, leading to complete and uniform impregnation.

The purpose of the invention is the expansion of technological capabilities by ensuring the separation of the material into fibers and improving the quality of the material obtained.

The goal is achieved by the fact that according to the method of treating a fibrous material by mechanical reduction when moving it through an annular working chamber formed by internal and external working bodies, one of which is vibrated by rotation of an unbalanced mass, mechanical reduction is carried out when the working chamber is filled with material 20-70% of its volume and amplitude of oscillations of the working fluid in the range from to

,

15

where D is the internal diameter of the external working fluid;

d is the outer diameter of the inner working fluid.

Mechanical compression of the material is carried out with a force of 1-15 kg / cm.

The method is carried out as follows.

Fibrous material, such as wood chips, is continuously fed into the working chamber, which is an annular gap between the inner and outer working bodies. One of the working fluids is reported to oscillate by rotating an unbalanced mass with respect to the axis of rotation (unbalance). The material is fed for processing in such an amount that the working chamber is filled with the material being processed at 20-70% of its total volume. At the same time, the amplitude of oscillations of the working medium should be within the range of - to the unbalance and the speed of its rotation should provide a compressing force of the processed material 1-15 kg / cm. As a result of repeated crimping, the material being processed is divided into individual fibers, which, when the treatment is continued, are ground to the desired degree of grinding. Conducted control over the change of the specified parameters in the course of processing according to the proposed method allows to establish the limits of change of parameters within which the processing according to the proposed method is feasible. a) The degree of filling of the working chamber with the material being processed can vary in the range of 20-70 / o of the total volume of the working chamber. Reducing the filling of the working chamber below 20% drastically reduces the productivity of the process, and an increase of over 70% makes it difficult to run-in and can lead to filling the entire working chamber with the material being processed, stopping the running-in, and as a result, drastically reducing the compression force that is insufficient crushing of the material, i.e. for implementing the method. b) The magnitude of the oscillation amplitude of the working medium from the middle position is established under various processing conditions. The maximum amplitude corresponds to the minimum load of the working chamber and approaches the value, and the minimum amplitude corresponding to the maximum filling of the working chamber, at which the material being run in and crushed, is -. where O is the internal diameter of the external working fluid; d is the outer diameter of the inner working fluid. c) The compressing force of the material during processing should be set within 1-15 kg / cm2. Compression with a force of less than 1 kg / cm2 does not allow crushing and fiber separation of even soft chips subjected to intensive chemical treatment, and over 15 kg / cm can lead to the creation of places of low stress concentrations exceeding the tensile strength of an individual fiber, which is accompanied by the cutting of cellulose fibers. Examples of the method. Comparative experiments were carried out using a specially manufactured apparatus consisting of two hollow cylinders arranged one inside the other and forming an annular working chamber. Running a smaller cylinder on the inner surface of the larger cylinder is created by rotating the drive shaft with unbalance, mounted on bearings in the inner cylinder. Due to the fact that when processing chips by a known method (prototype) is not reached. its separation into fibers (the amount of incomplete penetration is more than 90 ° / o), and the degree of grinding when processing the fibrous mass remains unchanged, in order to assess the level of indicators of mechanical strength of the formation of "" "....,. , „„ „„ „... of the bottomed material, its indicators are compared with the indicators achieved by grinding chips to the same degree of grinding in a disc mill, usually used for this purpose. Example 1. Birch wood chips are heated with a 2% sodium hydroxide solution for 1.5 hours at 100 ° C, after which the wood chips are divided into two parts, one of which is milled in a sprout Waldron disc mill, and the second part is processed on the proposed method. Three variants of the proposed method are tried, which differ in the conditions of the treatment. In the first embodiment, chips are continuously fed into the apparatus at a speed of 90 kg / h. The weight of the set unbalances provides the material compressing force of 5 kg / cm, the drum deviation from the average position when running in according to the measurement is 7.5 mm, which at values of D 240 mm and d 210 mm corresponds to a deviation of approximately -4 -. determining the degree of filling of the working chamber during processing, the process is interrupted, and the material in the apparatus is collected and its volume is measured, which is 70% of the volume of the working chamber. The passage of the material through the apparatus in this and subsequent versions is repeated six times with intermediate washing and sorting of the mass after the first passage. Determine the amount of waste (lack of penetration) after the first transmission, as well as the degree of grinding (° SR) and the mechanical strength of paper castings with a density of 75 g / m after the sixth transmission. According to the second variant of the proposed method, the processing is carried out in a similar manner at a speed of passing the material through the apparatus of 35 kg / h. the drum deviates from the average position during processing 10 mm () and the filling level of the working chamber during processing is 45 / o. According to the third variant, the material passing through the apparatus is 16 kg / h, the drum deviation from the average position during processing is about 15 mm ( --j-), and the degree of filling of the working chamber with the material when processing is 20%. Obtained in this example and presented in table. I results show that a decrease in the filling level of the working chamber from 70 ° / o to causes an increase in the running-in amplitude from () to) and leads to a more complete separation of chips into fibers — the amount of incomplete penetration and the decrease in the amount of waste sorting,% 5,31,7 0,2

The degree of grinding, ° WF 4350 5860 7020 Breaking length, m

Resistance to fracture, hpd. Resistance to bursting, kg / cm21.5 2.2

Comparison of the mechanical strength of the fibrous material, processed by the proposed method and milled in a disk mill, indicates a higher performance achieved by processing by the proposed method. The breaking length and resistance to bursting increase on average by 15%, and the resistance to fracture increases by 1.5 times.

Example 2. Birch chips are heated with a 2/0% sodium carbonate solution for 1.5 hours at 100 ° C, then separated

Table 1

23 35 60

23 35 60 3760 kJkQ 6250

18 104 273

15

37

190

into two parts, one of which is ground in a disk mill, and the other is processed in accordance with the proposed method. The weight of the installed unbalance provides a compressing force of 10 kg / cm. The deviation of the drum from the average position when running in 10 mm (-j ---), and the degree of filling of the working chamber material 40 / o. The processing results of the proposed method, as well as obtained by grinding in a disk mill, are presented in table. 2. It goes from 5.3% to 0.2% and to an increase in the degree of grinding from 23 ° to 60 ° SR, but is accompanied by a decrease in the productivity of the process. With an increase in the degree of filling of the working chamber with the processed material over 70% and, accordingly, with a decrease in the running-in amplitude less — the chips during processing cease to be divided into fibers (the amount of lack of penetration is more than 90 / o); Therefore, to assess the level of mechanical strength of the treated fibrous material in Table. I, for comparison, the indicators obtained by grinding chips to the same degree of grinding in a disk mill. 2.9 1.5 1.7 2.6

The yield of wood residue after chemical treatment,%

The whiteness of castings,%

The degree of grinding, ° SHR

Breaking length, m

Resistance to fracture, h. D. P.

Tear resistance, g

Burst resistance,

kg / cm

As follows from the table. 2, the processing of chips in accordance with the proposed method in comparison with the grinding on a disk mill provides an opportunity to significantly increase the strength of the obtained fibrous semi-finished product. The breaking length, resistance to bursting and tearing increases by 2-2.5 times, and the resistance to fracture increases from 1 to 73 ppm.

Example 3. Aspen wood chips incubated in a 5% solution of ammonia for 12 h

Indicators

The yield of wood residue after chemical treatment,%

The whiteness of castings,% The degree of grinding, ° SHR Breaking length, m Resistance to fracture, ch.p. p. Resistance to tearing, g

Burst resistance, kg / cmTable

at room temperature, and then divided into two parts, one of which is milled in a disk mill, and the other part of the chips is processed in accordance with the proposed method. The weight of the unbalance provides the chip retraction force of 15 kg / cm. The deviation of the drum from the average position - 12 mm (). the degree of filling of the working chamber with the material is 30%. The results are placed in the table. 3

Table 3

Processing on predismol on a disk lagged method of the mill

96.2

96.2 53.7 53.7 60 60

400

3100

132

ABOUT

k2

23

2.6

M

Claims (2)

Claim 1. The method of processing fibrous material 5 ° by mechanical compression when moving it through an annular working chamber formed by internal and external working bodies, one of which informs the oscillatory movement by rotation of an unbalanced mass, characterized in that, in order to expand technological capabilities by ensuring separation of the material into fibers and improving the quality of the resulting product, mechanical compression is carried out when the working chamber is filled with material at 20–70% of its volume and amplitude vibrations of the working fluid in D-d d-d -L ”- ^{up to} 2-; “Where D is the inner diameter of the body of the body; within the outer d - the outer diameter of the inner from the working body. 2. The method according to π. 1, characterized in that the mechanical compression of the material is carried out with a force of 1-15 kg / cm ² .