SU1473393A1 - Method of discharging from digester - Google Patents

Abstract

The invention relates to a method for unloading a digester and can be used in pulp, paper and paper industry during the periodic, pulping of sulphate and sulphite pulp. The purpose of the invention is to provide an effective process, due to the degree of BbiTecHeHHJFt liquor. The method of unloading the digester is to supply the washing liquid in the form of an upwardly directed jet of an annular section into the lower part of the boiler, filling it up, and selecting a slit. ka and removing fibrous mass. The washing liquid is fed with a speed of 0.6-0.9 m / s to fill the boiler, then the speed is increased to 1.5-2.0 m / s and the liquor is taken.

Description

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This invention relates to a method for unloading a digester and can be used in the pulp and paper industry. the process of ne -: - periodic cooking of sulphate and sulphite pulp.

The purpose of the invention is to ensure the efficiency of the process by increasing. The degree of displacement of liquor.

The method of unloading the digester is carried out by supplying the washing liquid in the form of an upwardly directed jet of an annular cross section to the lower part of the boiler, filling it up, sampling the liquor and removing the fibrous mass, the washing liquid is supplied at a rate of 0.6-0.9 m / before the boiler is filled, then the speed is increased to 1.5-2.0 m / s and liquor is taken.

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The values of the velocities of the jet of washing liquid, as well as the shape of the line, were found experimentally. Changing the shape of the jet and the deviation of its speed values in the period of filling the boiler and displacing the liquor from the proposed ones, worsens the results of the process. When the jet velocity in the period of filling the boiler is below 0.6 m / s and above 0.9 m / s, the degree of displacement and the relative concentration of liquor decrease, which is a consequence of a decrease in the uniformity of the flow rates of the pacTBOjia over the boiler section.

Similar results are obtained when the jet velocity of the industrial liquid during the period of liquor displacement, which differs from 1.5-2.0 m / s. At speeds below 1.4 m / s, the washing of pulp from organic

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The scientific research institute (experiments, 5,6 and 9) selection efficiency decreases.

substances, which reduces the degree of selection of liquor. At speeds above 2.0 m / s, the zone of turbulent mixing reaches the interface between the spent liquor and the washing liquid, which leads to a decrease in the degree of selection and the relative concentration of liquor.

Example. Experiments were carried out on my own.

a 5 m boiler, equipped with a cross section in the lower part of the boiler, a sieve in the upper throat and in the filling, liquor removal and removal of the lower one with a hydromonitor, which is a yarn fiber, which is a directional ring-and-up so that, in order to provide a slit nozzle, the boiler was loaded with process efficiency due to

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Claims (1)

Invention Formula Method of unloading the digester by supplying washing liquid in the form of an upwardly directed ring jet 20 0.4A tonnes of cellulose and 6.75 m of alkali solution; -Well-water was pumped out of the spent liquor, regulating its flow rate in such a way as to ensure the specified flow rate of flow from the jetting machine. After filling the boiler with liquid, the velocity was increased to 1.5–2.0 m / s and sampling of the solution was started from the upper neck. During the sampling process, displaced 25 samples were taken at equal intervals of time and the coherence was determined in them. alkali holding. According to the data obtained, the dependence of the concentration of the displaced solution on its quantity was built. and determine the degree of selection and the relative concentration. Experimental data on the dependence of the degree of selection and the relative concentration of the spent liquor on the flow rate of water from the monitor are presented in the table. From the results of experiments 2-4, 7 8. It follows that the proposed method provides a degree of selection of 90-92% with a relative concentration of 0.90-0.94. When the speed of the annular jet differs from the proposed increase in the degree of displacement of the liquor, the washing liquid is fed at a speed of 0.6-0.9 m / s before filling the boiler, then the speed is increased to 1.5-, 0 m / s and produced the selection of liquor. 35 40 The scientific research institute (experiments, 5,6 and 9) selection efficiency decreases. .. Invention Formula The method of unloading the digester by supplying the washing liquid in the form of an upwardly directed jet of an annular section to the lower part of the boiler, filling it up, extracting the liquor and removing the fibrous mass, so that, in order to ensure efficiency of the process due to increase the degree of displacement of liquor, the washing liquid is fed at a speed of 0.6-0.9 m / s to fill the boiler, then the speed is increased to 1.5-, 0 m / s and the liquor is taken.