SU1461374A3 - Method of controlling process of burning up lye with changing consistence in soda-regenerating unit - Google Patents

Abstract

A method to control the burning of liquor varying in its chemical consistency at the recovery boiler is disclosed. Considering the burning, for accomplishing the suitable size of the droplet in the recovery boiler, the viscosity of liquor will be controlled on the basis of density measurement, which, however, has proved to be an unreliable and slow way. To overcome these disadvantages the feeding parameters are controlled directly on the basis of the measured viscosity of liquor.

Description

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The invention relates to the pulp and paper industry and can be used to control the process of burning liquor with a varying consistency in a soda recovery unit.

The aim of the invention is to increase the efficiency of control.

Heat and chemicals used in cooking liquor are recovered for use in pulp production.

In the burned in sodoregleration unit contains about 40%. moisture that evaporates before droplets that fall to the bottom of the co-regeneration unit and collide with its surface.

For the most efficient operation of the recovery unit, it is necessary to obtain an optimal droplet size of the liquor injected through the nozzles into the furnace of the unit. The size of the drop is not determined by the condition of evaporation of moisture. With significant droplet sizes, most of the moisture evaporates from the surface of the glezer at the bottom of the recovery unit, which leads to an increase in the yield of sulfur dioxide in the flue gases leaving the unit. If the size of the droplet is small, then the moisture evaporates in front of the sleeper, which results in a higher quill content in the flue gas.

The droplet size is related to the viscosity of the liquor, which can be selected as a monitored parameter. By measured value

the liquor viscosity is controlled by the liquor squeezing process. .

i

Viscosity changes with change

consistency of both solids in the liquor and chemical consistency.

FIG. Figure 1 shows the change in viscosity with changes in the content of dry solid particles; . 2 shows the scatter of the viscosity of the woods (slice A) and the main fibers (section B) of wood with a different content of dry parts in FIG. 3 - deviations of the quality of the combusted liquor in time; on

FIG. 4 - a device that implements the proposed method.

The method is carried out as follows.

The magnitude of the change in the viscosity of the liquor burned in the furnace of the recovery boiler 1, controlled by a viscometer 2, immediately before regulation, goes to regulator 3. From regulator 3, the signal is sent to actuators 4, which change the flow of liquor, the pressure from which liquor is supplied to the regenerative the viscosity, which can be regulated, for example, by changing the steam flow rate in the heater 5. The viscosity change is also obtained by mixing the liquor with a flammable liquid having a viscosity that is different from lye.

FIG. 3, position A indicates the solids content, position B, viscosity after mixing in the tank, and position C, viscosity before feeding to the mixing tank. Section E illustrates the sequence of change with replacement of birch liquor with pine liquor.

The large change in viscosity shown in FIG. 3, which takes place in the nozzles for spraying liquor, causing sudden disturbances in the operation mode of the unit 1, is eliminated by adjusting the viscosity of the burnt liquor by preheating in block 5 by controlling the viscosity with a viscometer, set to the value D. changing the nozzle opening of the unit 1.

Claims (3)

1. A process control method for a liquefied liquor with a varying consistency in a sodoregeneration unit by measuring the physical parameter of the liquor, characterized in that, in order to increase the control efficiency, the viscosity of the liquor is selected as a physical parameter, depending on the value of which the liquor consumption is adjusted viscosity and pressure, with which the liquor is fed into the sodoregeneration boiler, the bone is measured immediately before the adjustment. 2. The method according to claim 1, of which the liquor consumption is controlled by changing the nozzle opening of the recovery unit. 31461374 3. The method according to claim 1, a different unit, is controlled by the displacement of u y and i with the fact that the viscosity is just with a flammable liquid, viscosity: the lock supplied to the soda recovery is different from the liquor viscosity. gaatI I with t1-i M 1 69 57 62 6J 64 S5 5ff S7 SS 63 Fiel 11 12 73/75 Phie 3 ; Compiled by G. Plotnikova Editor G. Volkov Tehred L. Oliynyk Proofreader. Girn to Order 548/59 Circulation 330 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 Production and printing company, Uzhgorod, st. Project, 4 20 RUM Subscription