SU1018661A1 - Method of determining optimal time moment for shutting down evaporation plant for cleaning - Google Patents

Abstract

A METHOD FOR DETERMINING THE OPTIMUM STOP TIME OF THE STEAM PUMP ON CLEANING by measuring the flow rates of the original and one stripped off solution, characterized in that, in order to reduce the specific evaporation costs, the flow rate and pressure of the steam supplied to the installation are also measured. The heat consumption and, when the change in its integral value reaches zero, determine the time for the installation to stop cleaning. (L

Description

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The signal for stopping evaporation The invention relates to methods for automatically determining the optimal stopping time for evaporating installations for cleaning, in particular in the microbiological industry in the production of fodobacterin, lysine, and can also be used in the chemical and food industries. There is a known method for determining the evaporator stop time by measuring the difference between the average cycle and the current plant performance and when it reaches zero to determine the stop time for the installation for cleaning 1. The method for determining the stopping time of the evaporator for cleaning by measuring the flow rates of the original and one stripped off solutions, the unit operation time between cleanings, comparing the performance losses by an arena water 2. The disadvantage of this method is that it is characterized for high unit cost of evaporation. In addition, the method is limited in use, since it can only be used with a monotonous change in performance, since the determination of the installation stop time is actually made from the necessary condition for the maximum of the function — zero equality of the first derivative. The purpose of the invention is to reduce the specific evaporation costs. The goal is achieved by the fact that according to the method of determining the optimal stopping time of the evaporator for cleaning, including measuring the flow rates of the original and one stripped off solution, the flow rate and pressure of the steam to the installation are additionally measured, the heat energy consumption is determined by the specified parameters values of zero determine the stopping time of the installation for cleaning. In the microbiological, food and chemical industries, evaporation plants are an intermediate in processing the incoming product. In this case, the capacity of the residue is determined by the capacity of the previous compartment, and the purpose of controlling the installation is to ensure the minimum consumption of thermal energy per unit of evaporated moisture for a given performanceff Tr U (T) Z / Qi (i :), Z WiCT:) W3as, where Wj - current installation performance; Q.i is the consumption of thermal energy per unit of evaporated moisture; setpoint installation performance; Tr - the duration of the installation; W is the number of plant operation cycles in the control interval in question. The drawing shows the implementation of the proposed method. On the line of the initial solution in the evaporator unit 1, the flow sensor 2 is installed, and on the line of the evaporated solution - the flow sensor 3. A flow sensor 4 is installed on the steam supply line, and a pressure sensor 5 is installed in the heating chamber. The outputs of sensors 2-5 are connected to a computing unit 6, which is connected to an integrator (block) 7, the output of which is connected to an extremum search unit 8. The method is carried out as follows. Based on the readings of sensors 2 and 3 of the flow rate of the initial (G) and one stripped off (Gg) solutions in the computing unit 6, the current capacity of the evaporator W G1 is calculated - Gj - Then, using the obtained results and readings of the steam flow sensors 4 (Gn) and pressure 5 (P,), the calculation of the specific consumption of thermal energy for evaporation and Gn CPnVn, where T (RP) is the specific heat of vapor condensation, which is a function of pressure; GH - steam consumption. In block 7, the accumulation of the results of the calculations coming from block 6 is made, and then the approximation and integration of the function Q (T :) is performed. The results obtained in block 7 are transmitted to block 8 of the extremum search, where the rate of change of the Eu / Et integral function is determined. When the rate of change is zero, a signal is given to stop the evaporator. For batch devices, there is an optimal ratio between the non-stop operation time and the stopping time for cleaning. In evaporation plants, this is due to the fact that, due to scale formation during operation, their productivity decreases and the unit costs increase. Continuing work at decreasing productivity and increasing unit costs becomes inefficient: it is more profitable to shut down the plant and clean it. However, overly frequent shutdown is also ineffective.

The proposed method provides a reduction in unit costs by 2.5%; increases labor productivity due to advance information of personnel about the time of the proposed shutdown of the installation and timely preparation for the launch of the next evaporator in continuous production.

The economic effect in the production of forabacter will be 150,000 rubles per year. The estimated need of the microbiological industry in facilities using the proposed method is 10. At the same time, the economic effect only in the microbiological industry will be 15,000 rubles. in year.

Claims (1)

METHOD FOR DETERMINING THE OPTIMAL STOP TIME OF THE VAPOR UNIT FOR CLEANING by measuring the flow rates of the initial and evaporated solutions, characterized in that, in order to reduce the specific cost of evaporation, the flow rate and pressure of the steam supplied to the unit are additionally measured, the specific heat energy consumption is determined by the indicated parameters and when the rate of change of its integral value of zero is reached, the time for stopping the installation for cleaning is determined. SU <„> 1018661