RU2459024C1 - Method of processing balances contaminated by rot - Google Patents

Abstract

FIELD: textiles, paper.

SUBSTANCE: method involves sorting of balances with the selection of defective ones, separation from them those parts of the stem with length of 0.5-0.8 m, which are visually identified as contaminated by rot. These parts are subjected to peeling and chopping at the wood chips in a separate stream. Chips are cut and sorted on the program in accordance with a given size of chips on the length and thickness. Then all chips are crushed and sorted to obtain fractions consisting of acceptable chips in the form separated to the longitudinal fragments, and the fraction containing wood fines and particles of rot.

EFFECT: reduced duration of treatment of wood chips and reduction of power consumption during processing of pulpwood.

5 cl, 3 ex

Description

The method relates to technologies for producing technological chips from pulp wood and can be used in the pulp and paper industry.

Wood for pulp production comes in the form of technological chips or in the form of pulp wood. Balances on the exchange are stored in piles or piles in the open, often for two, three or more years. With prolonged storage, the balances naturally rot, first of all, from the ends, and also in the presence of deep damage to the trunks - in the places of damage. Aspen wood, as well as Siberian and Daurian larch wood, are most susceptible to decay, possibly due to the anomalously high - up to 30% - content of arabinogalactan in the last polysaccharide. When processing rotten damaged balances into wood chips to obtain high quality fibrous materials, we should process and sort it in order to remove rot as much as possible.

Known technology for cleaning wood chips from rot, which is carried out in a special installation (AS 632784, IPC D21B 1/02, publ. 15.11.1978). In this technology, wood chips are fed from the feeder with water to a mixer hopper, from which the mixture is fed to a disintegration chamber, where the chips are treated with high-voltage pulsed electric discharges. Due to the high pressure of the plasma in the discharge channel, high pressure is created in the working fluid, under the influence of which the chips being processed breaks along the fibers, mainly in weak places affected by rot. She is washed out of the wood material. Next, the processed wood chips are sorted, rot is trimmed and a conditional material for cooking fibrous semi-finished products is obtained.

The disadvantage of this method is the complexity of the equipment for its implementation, high energy consumption.

The closest in technical essence and purpose to the proposed invention is a method for cleaning wood chips from rot by chopping and subsequent sorting (as.with. 1542981, IPC D21B 1/02, publ. 02.15.1990). In the method, wood chips chopped with the expectation of a 20 mm length are conditioned as follows. First, it is sorted by length. Wood chips with a length of more than 25 mm (top product) are sent for additional cutting and then all wood chips are sorted into fractions of 25-15, 15-10 and less than 10 mm, each fraction is separately sorted by a given thickness. Products remaining on the sortable base (top products of the second sorting) are again sorted by the specified thickness. Less thick wood chips (screenings) with a rot content of 1-5% are considered conditional and sent to the production of fibrous materials. Thicker wood chips in fractions of the specified length (the upper product of the third sorting), the most contaminated with rot, are sent to grinding. Less durable rot is crushed to a greater extent than wood. The crushed chips are sorted by sifting through a sieve with holes of 5 mm rot particles. The purified material is considered acceptable and sent to the production of fibrous semi-finished products.

The description of this invention does not indicate that the chips to be cleaned are prepared exclusively from the parts of the balances known to be infected with rot. It can be assumed that they process all wood chips obtained in aggregate from the entire balance, with the time and labor that are proportional to the volume of wood chips. Therefore, the disadvantages of the method should be considered its great duration and considerable complexity.

The new positive results from the use of the invention are the reduction in the duration of chip processing and the reduction of energy consumption in the process, since conditioning on the permissible content of rot in the chip is subjected only to that fraction which is obtained from the parts of the balance affected by the rot. This part makes up 20-30% of the total volume obtained from the damaged balance of wood chips. In addition, some milling and sorting operations are excluded from the process.

Another positive result is an increase in the degree of useful use of wood components by utilizing rot and rotten wood flesh.

These results are achieved by the fact that in the method of processing rot-infected balances, including debarking, chopping into chips and sorting according to the program in accordance with the specified dimensions by length and thickness, re-chopping part of the chips, grinding chips and sorting them to obtain products acceptable for of the manufacture of fibrous semi-finished products, according to the invention, before the debarking, end parts 0.5-0.8 m long affected by rot are separated from the balances, their debarking is carried out in a separate stream, they are crushed and sorted all wood chips and get a fraction consisting of acceptable wood chips in the form divided into longitudinal fragments and a fraction containing wood fines and rot particles, while the middle parts of the balances that do not contain rot are chopped into chips in the total stream of processed balances. In the presence of rot penetrating the sound wood in the middle part of the balances, the affected lobes of the trunk are cut out in the form of churaks and processed into chips together with the end parts. The larch balances of Siberian and Daurian and aspen are subjected to processing. Chips are crushed in an apparatus selected from the group comprising a hammer mill, twin-screw apparatus, and disk defibrator. The fraction containing wood fines and rot is sent to the production of vanillin.

The method is as follows. When disassembling piles and / or piles of balances, the balances damaged by rot are selected, the end parts 0.5-0.8 m long are separated from them, if there are foci of rot in the middle part they are cut out in the form of chura and create a predetermined supply of this material. It is processed in a separate stream. Pieces of balances are debarked in a skew drum. Under the influence of impacts, friction is stripped not only of bark, but also surface and surface rot and part of rotten wood are erased and crumbled in the form of dust and crumbs. The barked material is cut into chips in accordance with a given program of parameters along the length of the chips, for example 20 mm, and a thickness of 5 mm. Chips are sorted in the appropriate devices according to their length and thickness to obtain the top product, the middle product is the chip fraction that does not exceed the parameters specified in the program, and the screenings are in the form of wood fines and rot with particle sizes less than 5 mm. The top product consists of knotted thick chips and chips with a length of more than 20 mm. He is being returned to the cabin. All material after these operations is subjected to grinding in a twin-screw apparatus. A hammer mill or disk defibrator can also be used. The crushed material is sorted to obtain split into longitudinal fragments of acceptable size and content of rot of wood chips, which can be used for the production of fibrous semi-finished products. The rot content in this final product processing balances 1-4 (%) wt.%.

The screening during sorting consists of trifles of rotten wood and particles of rot and dust. It is combined with material similar to it that appears after the first sorting.

As you know, lignin is one of the types of raw materials for obtaining a valuable substance - vanillin. Therefore, the product, which is a mixture of wood rot and rotten wood when the content of the mixture is 75-85 wt.% Lignin, is a very convenient raw material for obtaining the aforementioned substance.

The following examples illustrate the proposed method.

Example 1. Processing damaged by rot balances of aspen wood. The volume of assembled end-parts damaged by rot and churak from the middle parts of the balances is 30% of the volume of sorted balances to be processed. The healthy parts of the balances are sent for standard processing, the resulting chips - in the production of pulp by the sulfate method of cooking.

Damaged rot parts of the balances in a separate stream are debarked in a picking drum and chopping according to a program specifying a chip length of 20 mm and a thickness of 5 mm. The resulting chips are sorted by length and thickness and get the top product with a chip length of more than 20 mm and / or a thickness of more than 5 mm, a middle fraction containing chips with a length of 20 to 5 mm and a thickness of 5 to 3 mm, and a screening consisting of trifles of rotten wood and pieces of rot.

The top product is returned to the chipper. The average product is subjected to grinding in a disk refiner and sorting on a sieve with a hole size of 5 mm to obtain split into longitudinal fragments of acceptable size and rot content (not more than 4 wt.%) Wood chips and screenings containing particles of rotten wood and rot. The yield of chips 72% of the mass of barked raw materials, the mass of screening 28%.

Wood chips are sent to the production of HTMM, screenings are sent to the production of vanillin.

Example 2. Process damaged by rot parts of the balances of wood of larch Siberian and Daurian. Its volume is 24% of the sorted balances to be processed. The average product is ground in a twin-screw apparatus. Processing conditions and products are similar to those indicated in Example 1. The rot content in the sorted chips is 4 wt.%. Chips yield 76%, sieving mass 24%. Chips are used for pulping by the sulfite method, screenings are used to produce vanillin.

Example 3. The raw material is similar to that used in Example 2. The difference from Examples 1 and 2 is the use of a hammer grinder for grinding the average product. The remaining process parameters, as well as the characteristics of the final products are similar to those given in Example 2.

Claims (5)

1. A method of processing rot-infected balances, including debarking, chopping on wood chips and sorting according to the program in accordance with the specified size of wood chips by length and thickness, grinding part of the wood chips and sorting them to obtain products acceptable for the production of fibrous semi-finished products, characterized in that Before debarking, end parts affected by decay 0.5-0.8 m long are separated from the balances, their debarking is carried out in a separate stream, whole chips are subjected to grinding and sorting, and a fraction containing an acceptable chips in divided into longitudinal fragments, and a fraction consisting of wood fines and rot particles, while the middle parts of the balances that do not contain rot are cut into chips in the general stream of processed balances. 2. The method according to claim 1, characterized in that in the presence of rot penetrating the sound wood in the middle part of the balances, the affected lobes of the trunk are cut out in the form of churks and processed into chips together with the end parts. 3. The method according to claim 1, characterized in that the balances of Siberian and Daurian larch and aspen are subjected to processing. 4. The method according to claim 1, characterized in that the chips are crushed in an apparatus selected from the group consisting of a hammer mill, twin screw apparatus, and a disk defibrator. 5. The method according to claim 1, characterized in that the fraction containing wood fines and rot is sent to the production of vanillin.