RU1770952C - Method of automatic control of steam separation process in evaporators - Google Patents

Abstract

Usage: food industry, in particular sugar. SUMMARY OF THE INVENTION: automatic stabilization of the steam velocity at the inlet of the separator and the suppression of foam by changing the cross section of the inlet of the separator. 1 ill.

Description

The invention relates to the sugar industry and can be used in other branches of the food industry.

A known method for the automatic control of a multi-case evaporator installation (see C 13d 1/06, AS USSR No. 486046, publ. 30.09.75). However, the separation of the secondary vapor in this unit is unregulated.

Evaporators with remote separators are known which do not solve the problem of suppressing foam, which impairs steam separation (see E. Senesh, N. Nadaban, Evaporation Processes in Food Production Ed. Food Industry M. 1969, p. 88).

In the sugar and dairy industries, the evaporation process takes place in a variable mode, this is due to the different quality of the processed raw material (product), as well as when the evaporators are put into operation. In addition, with increased foaming, the efficiency of the evaporator decreases, the entrainment of the solution with secondary vapor increases, and therefore it becomes necessary to act on the separator. However, existing separators in sugar and milk

industries are made unregulated, i.e. Designed for continuous operation.

The aim of the invention is to remedy these drawbacks, i.e. foam suppression, increasing the productivity of the apparatus and reducing the loss of the working solution by reducing its entrainment with the secondary vapor.

The essence of the method for automatically controlling the process of steam separation in evaporators is to measure the speed of the secondary steam at the inlet of the separator, compare the measured value with the set value and stabilize the speed of the secondary steam by changing the input cross-section of the separator, control the ultimate level of foam in the separator and when it reaches its maximum value, block the entrance to the separator.

The drawing shows a schematic diagram of the automatic control of the process of steam separation in evaporators

The separator, made in the form of two truncated cones, the upper 1 and lower 2, mounted above the heating surface of the evaporator 3. On the outside

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The separator is equipped with a regulator 4, which is connected to the flange 6 of each separator slit by means of a tie rod 5. On the outside of the flanges, stiffeners and rings are attached, which are connected by means of a coupling to the regulatory body. To measure the speed of steam, the separator is equipped with a sensor 7, connected through a converter 8 and a secondary device 9 with a regulator 10, the task of which is set by the dial 11, based on providing a given steam speed at the inlet of the separator, by acting through an actuator 12 and a regulating body 4 for flanging the separator. The separator is also equipped with a sensor 13 (contact electronic level gauge), an electronic block indicator level 14, switch 15.

A method for automatically controlling the steam separation process in evaporators is carried out as follows.

The value of the task set by the setter 11 is proportional to the optimal steam speed at the inlet to the separator, and subject to the normal process of evaporation of liquids, the inlet to the separator will be in the open state, which will also correspond to the optimal performance of the evaporator. In violation of the technological regime, for example, in the case of a decrease in the efficiency of the evaporator, the steam velocity at the inlet to the separator decreases by V V and the signal from the sensor 7 through the converter 8 goes to the secondary device 9, which registers the deviation of the steam velocity at the inlet to the separator, compares with the value of the reference from the switch 11 and the generated unbalance signal is fed to the input of the controller 10. The controller converts the input signal in accordance with the regulation law laid down in its basis. In this case, the magnitude of the output signal and its rate of change are proportional to D V, as a result of which the regulator 10 acts on the regulator 4 by means of the actuator 12, which covers the flanges of the separator 6, thus

reducing the input section of the separator. The process of reducing the input cross section of the separator continues until the optimal (predetermined) steam velocity is restored to

the entrance to the separator. As the steam velocity increases, the inlet section of the separator will increase, thereby stabilizing the steam velocity at the inlet of the separator. When thickening foaming liquids and

a possible occurrence of foam in the separator is triggered by a sensor 13. The operation of the sensor is based on the property of the foam to conduct electric current. When the foam rises to the level at which the sensor is installed, the electric circuit is closed, the electronic unit of the level indicator 14 is activated, and through the switch 15 it turns on the actuator 12, then the regulating body 4 covers the input section of the separator, or completely closes it, which helps to suppress the foam. If there is no foam in the separator, the circuit opens and the inlet cross section of the separator increases to the optimum size.

Implementation of the proposed method for automatically controlling the steam separation process in the sugar industry will provide an economic effect by reducing the entrainment of sugar with secondary steam, as well as increasing the productivity of evaporators by stabilizing the steam separation process and, consequently, the evaporation process.

Claims (1)

The claims A method for automatically controlling the steam separation process in evaporators, characterized in that, in order to suppress the foam and increase the productivity of the apparatus by reducing the loss of the working solution and its entrainment with the secondary steam, the speed of the secondary steam at the inlet of the separator is measured, the measured value c; set and mismatched in size, stabilize the speed of the secondary steam by changing the input section of the separator, control the limit level of foam in the separator and, when it reaches its maximum value, block the entrance to the separator. CH1 4 - w