SU970068A1 - Method and apparatus for controlling roasting of expanding materials - Google Patents

Description

(54) METHOD FOR MANAGING THE PROCESS OF BURNING WITHOUT MATERIALS AND A DEVICE FOR ITS IMPLEMENTATION

t2 The invention relates to the production of intumescent building materials, such as expanded clay, predominantly in rotary and ring furnaces with baking heat exchangers. There is a known method for controlling the process of burning claydite, which consists in stabilizing fuel consumption / changing the rotation frequency of the furnace and feeding the semi-finished product depending on the deviation of the bulk density of the clay from the target, as well as a device for carrying it out, containing a meter and a bulk density indicator connected to the inputs of the device are compared, the output of the latter being connected to the inputs of the frequency regulators of the jqeHHH furnace and the supply of the semi-finished product TlJ. Firing process control with the use of this method and device is inefficient due to the low transmission coefficient over the channel, kiln rotation speed - bulk density. In this case, the need for deep regulating effects will cause a disturbance in the process in all zones preceding the swelling. The closest to the invention is a method 2 for controlling the process of calcining claydite, including the correction of the calcining temperature by varying the fuel supply according to the deviation of the bulk density from the target and stabilizing the furnace power, and the device for its implementation,. including a meter and a bulk density adjuster connected to the inputs of the comparison unit, which is connected to the firing temperature stabilizer G1 2 through a correction regulator. This method and control device allows stabilizing the bulk density of the claydite, however, does not provide a significant increase in the furnace productivity due to that for control is not. The second most important process parameter is used: firing time (kiln rotation frequency. The aim of the invention is to increase the kiln performance. It is achieved there that the method of measuring and stabilizing the bulk density of the finished product influences the nyTeivi firing temperature and changes the fuel supply frequency furnaces, for example, periodically in the direction of its increase until the density of the finished product exceeds the specified limits, after which the frequency of rotation of the furnace is reduced to the occurrence of in order to improve the quality of control, it is possible to adjust, respectively, in the direction of increasing or decreasing the firing temperature, and to measure and stabilize the bulk density, the density of the semi-finished product is adjusted. representative fractions of the finished product, and not the Variable mixture. In addition, the frequency change in the furnace aperture is performed through discrete time intervals determined by the rate of change of those semi-tics. A device containing a firing temperature controller and a bulk density adjuster, which is connected to the second input of the comparison head, is additionally inserted into the device containing a measuring instrument for the density of the finished product, connected through a serially connected unit of control and a sensor to the regulating input of the firing temperature controller and the bulk density regulator. a signal, a correction unit and controllers of the frequency of rotation of the furnace and the supply of a semifinished product, the outputs of the comparison unit and the setpoint generator are connected to the outputs of the control signal generation unit NOSTA ASW, and the output is coupled to inputs of the regulators and the rotational frequency furnace and corrective feeding semifinished block, whose output is connected to the second input of the temperature controller of the torus. The control signal generating unit may contain an averaging unit connected via a serially connected driver, a logic unit and a converter to the input of the limiter, the output of the driver is also connected to the input of the pulse generator, the output of which is connected to the second input of the logic unit, and the output of the comparison unit is connected to the input averaging unit, and the output of the unit on the bulk density - to the second input of the molds. The drawing shows a block diagram of a device for implementing the proposed method. The main control effects of the calcination process of ceramsite and other intumescent materials are the temperature and calcination time, the change of which is carried out respectively by changing the fuel supply and the frequency of rotation of the furnace. It is advisable to stabilize the main quality indicator - bulk density by controlling the influence of the firing temperature, since the transfer coefficient of the object along this channel is maximum. In this case, disturbances associated with changes in the physicochemical properties of the raw material are compensated. The latter, as well as the fractional composition of the semi-finished product, which varies depending on the state of the processing equipment and other production factors (the coefficient of variation of the content of the main fractions of the semi-finished product on separate specimens is 2030% during the shift), also determines the optimal firing time . The bulk density of intumescent materials of the invariant to insignificant (10–20% change in firing time, at the same time, the furnace performance with stability of bulk density and constant furnace fill ratio is directly proportional to the rotation frequency of the latter. Therefore, setting the maximum rotation frequency of the furnace with synchronization at In this power supply of the furnace to semi-finished products and ensuring a predetermined amount of timber density, it is possible to achieve the greatest productivity of the furnace. The rotation of the furnace can be carried out using search methods. The device for implementing the proposed method works as follows .. At the outlet of furnace 1, meter 2 controls the bulk density of the finished product, preferably its most representative fractions. After comparing the signals of meter 2 and of the bulk density setting device 3 in the comparison unit 4, the error signal is fed to the controller 5, the correction task is set to the firing temperature controller b, which is a standard circuit of temperature abilization by impacting the fuel supply on a pulse from a thermal sensor (TepMCTiapa, pyrometer). Through this cascade scheme, the bulk density of the finished product is stabilized as the physicochemical properties of the raw material change. The error signal from the output of the comparator unit 4 is also fed to the input of the control signal generating unit 7. The latter contains averaging unit 8, designed to highlight the main signal and suppress random fluctuations.

The filtered error signal and the bulk density setting device 3 signal are fed to the inputs of the imaging unit 9, which realizes the functional dependence of the permissible limits of the bulk density deviation from the set value and outputs the normalized signal AIR: Exceeding these limits.

The 9th signal is fed to the input of the logical unit 10, the second input of the second module is supplied with a signal from the pulse generator 11, for example, in the form of a series of pulses.

The operation algorithm of the logic unit 10 is presented in the table.

Note:: The direction of influence corresponds to different directions for the output signal of a logic block. During operation, a situation may arise when, during a paus between the generator series, 11 pulses, with deep disturbances of the process to Consequence At near-limit frequencies of rotation of the furnace, the bulk density stabilization contour will not provide a chm-sensing disturbance and the bulk density will go beyond the prescribed limits (going out in the opposite direction is impossible in principle). . In order to eliminate such a possibility, the signal of the imaging unit 9 is also fed to the input of the generator 11 pulses, ensuring that it is forcedly started in the indicated case (therefore, the table does not contain 4s of the O, + signals). In this case, a control signal is given to decrease the frequency of rotation of the furnace, and thus conditions are created to stabilize the bulk density of the finished product with a corresponding circuit. The pulse output signal of logic unit 10 is converted by converter 12 (for example, of integrator type) into a DC signal supplied as a correction through limiter 13 to the inputs of the rotational speed controllers 14 and 15 and the power supply of the furnace with a semi-finished product. The controllers 14 and 15 are the stabilization circuits of the corresponding parameters and contain the necessary elements and sensors. The limiter 13 limits the output signal of the converter 12 for a given minylum and maximum c - the presence of a signal; o - no signal. 30 to prevent the emergency operation of the furnace in case of possible malfunction of the device. When changing the frequency of rotation of the furnace and, accordingly, the supply of the semi-finished product, disturbances are introduced into the temperature mode of operation of the furnace. Therefore, in order to improve the quality of control, the device introduces a correction regulator 16, made in the form of a dynamic communication device and providing a forwarding signal to the temperature controller b in transient (rotational frequency) operating modes of the furnace. Thus, the device implements a search The method of controlling the firing process, in which the maximum possible for a given technological situation, the purity of the rotation of the furnace and the supply of the semi-finished product with the observation of the quality requirements of the product and firing, and the most ensured close to maximum kiln performance, the application of the proposed method and device for controlling the firing process is most appropriate for kiln units in which preliminary heat treatment and melting are carried out in different heat apparatuses, for example, in rotary and ring kilns with baked heat exchangers, since the heat treatment mode in this case can be stabilized by separate local circuits. Estimated increase in performance of expanded clay kiln 3-5%,. that with its productivity of 100 thousand mzv year creates an economic effect of 25-40 thousand rubles.

Claims (4)

Invention Formula 1. A method for controlling the firing process of expanding materials, including measuring and stabilizing the bulk density of the finished product by affecting the firing temperature by changing the fuel supply, which is different from the fact that, in order to improve the furnace performance, the rotation frequency of the furnace is changed, for example, periodically, towards its increase until the bulk density of the finished product exceeds the specified limits, after which the kiln rotation frequency is reduced to the bulk density entering within the specified limits, and when the rotation frequency changes, the semi-finished product is fed into the kiln. 2. Method POP1, characterized by the fact that, when the rotation frequency of the kiln is changed, it is corrected accordingly in the direction of increasing or decreasing the firing temperature. 3. The method according to Claim 1, differing from 10 to 1 with the fact that the bulk density of representative fractions of the finished product is measured and stabilized. 4. The method according to claim 1, characterized in that the change in the frequency of rotation of the furnace is carried out at discrete intervals determined by the rate of change of the characteristics of the semi-finished product, 5, a device for implementing the method according to claim 1 and 2, containing a bulk density meter the product connected through a series-connected unit, a comparison and a correction controller) to the input of the firing temperature controller, and the bulk density setting device, connected to the second input of the comparison unit {characterized in that / in addition to it a control signal generation unit is inputted, to the inputs of which the outputs of the comparison unit and unit of bulk density, as well as controls the frequency of rotation of the furnace and the supply of semi-finished and adjustment block, the inputs of which are connected to the output of the control signal generating unit. 6. The device according to claim 5, wherein the control signal generation unit comprises an averaging unit connected via a serially connected driver, logic unit and converter to the input of the limiter, the driver output is connected in the same way to the input of the pulse generator, the output of which is connected to the second inputs of the logic unit, where the output of the comparison unit is connected to the input of the averaging unit, and the output of the setpoint gauge to the second input of the former. . , Sources of information (aci, taken into consideration during the examination 1. USSR author's certificate number 461264, cl. From 04 To 33/32, 1975. 2.Ratnovsky V.Ya. and others. Automation of production of expanded clay. building materials, 1976, 9.