SU887905A1 - Method of automatic control of heat condition in slot-type furnace - Google Patents

Description

I

The invention can be used in building materials.

A known method of automatically controlling the thermal regime in a slit furnace, which includes measuring the rate of temperature change, the moments when the conveyor belt stops, and the adjustment of the flow of coolant and cooling agent in accordance with these parameters 1.

The disadvantage of this method is the need to compensate for large disturbances by complicating the circuit in order to improve the transient time in the system.

The closest in technical essence is a method of automatic regulation of the thermal regime in a slit furnace, including changing the coolant supply to the heating and firing zones, supplying a cooling agent to the boundary of the burning and cooling zones, and measuring temperatures in the heating, firing and cooling zones (2.

This method is based on changing the flow rate of the cooling agent depending on the temperature2

Temperatures at the beginning of the preheating zone. However, the temperature in the preheating zone is created by the flow of heat-transfer fluid and combustion products that are sucked from the burning zone through the preheating zone. Temperature control only by changing the heat carrier flow in the preheating zone reduces the dynamic diameters of the control, which leads to an increase in the transient time, i.e. the time during which the nominal process condition is varied. This leads to an increase in product waste.

Claims (2)

Changing the amount of coolant supplied to regulate the temperature in the cooling zone (and, for example, decrease), with a constant suction capacity of the cooling zone suction fan leads to a more intensive suction of combustion products from the burning zone. In this, the burning zone is shifted along the firing motion. This also leads to violations of the technological mode of firing, since the rate of change in temperature 3 of the products to be burned increases at a uniform rate of their movement along the furnaces. The purpose of the invention is to improve the quality of regulation. This is achieved by the fact that in the method of automatic thermal control in a slot furnace, including changing the flow of coolant to the heating and calcining zones, supplying a cooling agent to the boundary of the calcining and cooling zones, and measuring temperatures in the heating zones, calcining and cooling, additionally change the intensity suction from the cooling zone and the heating zone, we will accept, the change in the supply of the coolant to the heating zone and the change in the intensity of the scoop from this zone are made depending on the deviation of the measured temperature. The variations of the supply of heat-transfer agent to the burning zone are carried out depending on the deviation of the measured temperature of the secondary zone from the predetermined value, and the change in the suction intensity from the cooling zone is most important depending on the deviation of the measured temperature of this zone from the specified value. in the following. The temperature change in the preheating zone is carried out by simultaneously changing both the consumption of combustible fuel and the intensity of suction of combustion products from the roasting. In this case, a significant reduction in the transient process time is achieved, with disturbances in the preheating zone, which leads to a reduction in the scrap of fired products due to a significant reduction in the time of deviation of the set temperature from the nominal one. It is proposed to control the temperature in the cooling zone by varying the suction intensity of the cooling agent from the cooling zone. At the same time, the boundary of the burning zone is 6ojfee rigidly fixed, since a stable air curtain is created on the border of the burning and cooling zones. In turn, this leads to a more accurate observance of the firing mode and, as a consequence, to a reduction in the scrap, baked products. The method of automatic regulation is explained by the scheme, where 1 is a damper that changes the suction intensity of the combustion products from the preheating zone; 2, 3 - dampers, changing coolant flow rate; 4 - damper, changing the intensity of suction from the zone cooled 5, 6, 7 - regulating devices; 8, 9, 10 - temperature sensors; 11, 12, 13-temperature settings. If a disturbing action occurs in the preheating zone, the temperature sensor 8 changes the signal value in accordance with the temperature being changed. In the regulating device 5, the signal from the sensor 8 is compared to the signal from the sensor 11. In accordance with the magnitude and sign of the difference between the signals of the sensor 8 and the setting device 11, the regulating device 5 gives the command to open or close the valves 1 and 2 until the difference between the signals of the sensor 8 and the setting device 11 will not fall within the permissible zone. The regulating devices 6 and 7 work in the same way, each regulating the temperature in the swie zone. The regulating device 6 controls the flow rate of fuel supplied to the calcining zone, and the regulating device 7 controls the intensity of the suction of the cooling agent from the cooling zone. This method will improve the quality of regulation. Claim method for automatic control of thermal conditions in a slit furnace, including changing the coolant supply to the heating and firing zones, supplying a cooling agent to the boundary of the burning and cooling zones and measuring temperatures in the heating, firing and cooling zones, characterized in that with the aim of improving the quality control, they additionally change the suction intensity from the cooling zone and the preheating zone, whereby the change in the supply of the heat carrier to the heating zone and the change in the intensity of the suction from this zone depending on the deviation of the measured temperature of this zone from a predetermined value, the change in the supply of heat carrier to the firing zone is carried out depending on the deviation of the temperature measured in this zone from the predetermined value, and the change in the suction intensity from the cooling zone temperature of this zone from the set point. Sources of information taken into account in the examination 1. Copyright svdedetstvo USSR N 691662, cl. F 27 B 9/40, 1979. 2. USSR author's certificate N 364818, cl. F 27 V 9/40, 1973. Ho / flff e // ye i / ffjre // M O 4ftfgfff / f yj f / fff Ox ffJK ffWufffy fffwm