SU1180428A1 - Method of testing fibrous mass - Google Patents

Abstract

METHOD FOR TREATING FIBER MASSB1 by fibrillating it in a hydrodynamic cavitation field formed by the flow of pulp flow under pressure in a cavitation reactor, characterized in that, in order to improve the quality of the pulp while maintaining energy consumption, fibrillating dehydration is used when fibrous flow is removed. the entrance to the cavitation reactor 125-190 m of water. Art., and at the exit of it 35-60 m of water. Art.

Description

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The invention relates to the processing of fibrous materials in a hydrodynamic cavitation field and is intended for use in the pulp and paper industry, the building materials industry and other sectors of the national economy, using fibrous materials as a raw material and can be used in the pulp and paper industry for pre-release and grinding waste paper, grinding cellulose.

Properties

the famous

Inlet pressure

75-120 m water column

Outlet pressure, m water line

Grinding degree, SR Weight of castings, g / m Strength,

As can be seen from the data in the table. 1, the best strength indicators are possessed by castings of waste mass, processed according to the method with the proposed parameters. At the same time, energy consumption for mass treatment does not increase.

Example 1. As a fibrous semi-finished product using waste carton brand "g Dissolution of waste paper is carried out in a laboratory pulper at a concentration of 3% to a petal size of 5-9 mm.

The processing of the pulp is carried out on a pilot cavitation installation, which is shown in the drawing.

The purpose of the invention is to improve the quality of the mass while maintaining energy consumption.

In tab. 1 presents the results of tests of castings made from waste paper, obtained by the known and proposed methods and two methods, one of the parameters of which goes beyond the proposed parameters.

Table 1

Indicators by the way

proposed

210

190

125-190

20

80

37

33

299

298

Waste pulp from tank 5, unground mass is pumped by pump 2 to cavitation apparatus 3. A working pump 4 of the installation repeatedly drives mass through cavitation reactor 5, with part of the mass being continuously discharged into ground tank 6. The mass pressure at the inlet of the reactor 1 is determined by the sum of the pressures of the worker 4 and the feed, its 2 pumps and is 125 m of water. at the outlet of the reactor Pj is the pressure of the feed pump 2 and is 35 m of water. Art.

The number of passes of the processed mass is determined by the ratio of the capacities of the working and feed pumps; it is 15 passes.

The specific energy consumption for processing at IT is 94 kWh / t.

Castings weighing 300 g / m are manufactured and tested from the treated mass.

Example 2. The mass pressure at the inlet to the reactor P is 160 m water. Art. and at the exit from it Pg - 50m water. Art. (the change of the bonnets and the performance of the pumps is carried out by changing their speed). The number of passes of the processed mass through the cavitation reactor is 11.

The specific energy consumption is equal to 94.5 kWh / t. Castings of 300 g / m2 are manufactured and tested from the treated mass.

Example 3. The mass inlet pressure to the reactor P is 190 m water. st and on

The weight of the casting, g / m 299 The degree of grinding, SR 32

Tensile strength. Comparative analysis of the data presented in Table. Figure 2 shows that the treatment of waste pulp according to the proposed method makes it possible to increase the strength properties of the mass and creates conditions for increasing the use of waste paper in the composition of paper and paperboard, reducing the mass intensity of the product without degrading quality. If an increase in pressure at the reactor inlet causes an increase in the electric power consumption for cavitation processing, experiments performed show that the increase in pressure at the reactor inlet (i.e., an increase in pump head) is fully compensated by a reduction in the processing time of the material in the cavitation outlet from it R - 60 m waters Art. The number of flows through the cavitation reactor 8 to be treated. The specific energy consumption is 93.8 kWh / t. Castings weighing 300 g / m are manufactured and tested from the treated mass.

Example 4. The mass pressure at the inlet to the reactor Pi is 190 m in. Art., and at the exit of it Pj. - 35 m waters. Art. The number of passes of the processed mass through the cavitation reactor 7. The permissible energy consumption is 95.0 kWh / t. Castings weighing 300 g / m are manufactured and tested from the treated mass.

In order to obtain comparable results, an experiment was conducted in parallel to prepare the mass according to a known method. The test results of castings weighing 300 g / m are given in table. 2

table 2

301

299

300 35 35 32 nominal reactor. The increase in pressure at the outlet of the reactor created by the pump, is accompanied by a very small increase in power consumption and does not cause an overall increase in energy consumption for the cavitation treatment process. The application of the proposed method is also useful when grinding fresh cellulose fiber. The morphological changes in cavitations during cavitation (cellulose fibers (external and internal fibrillation of fibers, accompanied with intensification of the processes of swelling and plasticization), lead to an increase in strength properties. This improves the processes of forming and dewatering the web and increases the strength of the sheet in the wet state.

Example 5. Cellulose from a pool of unground mass at a concentration of 2.6–3.2% by a feed pump under a pressure of 38 m of water. Art. continuously fed to the processing unit in the cavitation apparatus, where it is subjected to intensive processing in the cavitation field. From the apparatus, the pulp is also continuously fed to the grinding in a conical mill and then to the ground mass pool.

Cavitation mass treatment is carried out at a mass pressure at the inlet to

Weight 1 m, g

The degree of grinding, ° IIIP

Explosive load, kg

Breaking force for ring compression, kg

BDM speed, m / min

Specific energy consumption, kWh / t As can be seen from the table. 3, the use of cavitation treatment at the first stage 40 of pulp grinding allows to increase the strength properties of paper, to reduce

135 m water reactor. Art. and at the exit of it 38 m of water. Art.

According to the known technology, cellulose from the pool is unground mass at a concentration of 2.6–3.2% by a feed pump at a pressure of 38 m of water. Art. continuously fed for grinding into two successively connected conical mills and then to the ground mass pool.

The results of the test paper produced by known technology and in accordance with the invention, are given in table. 3

Table 3

199

190 23 8.0 23 7.8

18.0

17.6 37.6 37.6

150

150 to increase paper machine productivity while reducing power consumption,

Claims (1)

METHOD FOR PROCESSING FIBROUS MASS by fibrillating it in a hydrodynamic cavitation field formed when the pulp flows under pressure in a cavitation reactor, characterized in that, in order to improve the quality of the mass while maintaining energy consumption, fibrillation is carried out at a pressure of the pulp flow at the inlet to the cavitation reactor 125-190 m water. century, and at the exit from it 35-60 m of water. Art.