SU996447A1 - Method for determining working condition of devices for detecting burning-through in chilled member of metallurgical furnace - Google Patents

Description

The invention relates to ferrous metallurgy and can be used in the automation of blast furnaces.

Closest to the invention in technical essence is a method for detecting burnouts of a cooled element, including fixing the gas phase in case of violation of the tightness of the cooled element. A device that implements the method is made in the form of a separation vessel with a water lock and a pressure sensor, which detects a burnout of £ 13 with the appearance of gas in the gas cavity of the vessel. However, the known method has inherent disadvantages due to the low operational reliability of the device that implements the known method, for example, reduced sensitivity or failure in the operation of a separate element of the device.

The purpose of the invention is the provision of assessing the sensitivity and reliability of fixing burnouts of a cooled element of a metallurgical furnace by means of an operational check.

This goal is achieved by the fact that, according to the method for determining the operating state of burnout detection devices for a cooled element 'metallurgical furnace, including fixing the gas phase in case of leakage of the cooled element 5, · gas is introduced into the refrigerant of the pressure pipe of the cooled element from the flow rate of refrigerant · agent 1, 0-3.0%.

The drawing shows a diagram 10 of the implementation of the method. ’

The circuit includes a cooled element 1 (air lance) of a metallurgical furnace / flow meter 2 of the amount of 'refrigerant (water); gas (air) quantity flow meter 3 electronic ¹³ stopwatch 4 / gas phase fixation sensor 5 (pressure); Device 6 for detecting burnouts of a cooled element (separating vessel), button 7 for controlling an executive body) executive valve 8 for gas flow, valve 9.

The circuit corresponds to the absence of leakage in the cooled element 1 of the metallurgical furnace; as a device 6 for detecting burnouts of the cooled element, a • separation vessel is selected. At the time of the on-line check, to determine the sensitivity of the device 6, the control buttons 7 act on the executive body 8 to open the valve 9 and turn on the electronic stopwatch 4. Partial opening of the valve 9 corresponds to the flow of gas (air) in the form of bubbles into the cooling system of element 1 (air lance) and a gas (air) flow meter. By controlling the actuator 8 of valve 9 with a fixed opening of it, the response of the pressure sensor 5 can be used to determine the time using the electronic stopwatch 4 and the minimum ratio of gas flow to refrigerant flow, respectively, from flow meters 3 and 2.

To eliminate the influence over time of fluctuations in the flow rate of the refrigerant required for cooling the element, where $ ^{g is} taken as the criterion for evaluating the sensitivity of the device.

Q ^r .

· 400 ° / ο, ·. ^ΧΛ minimum gas flow rate fixed by the threshold of the device, l / h;

- refrigerant flow rate at the time of the test, l / h.

The accepted criterion for evaluating the sensitivity of the device is γ = 1-3%. The lower numerical limit is selected based on the results of a study of various devices on the threshold of their operation. The upper limit is limited due to the influence of the gas introduced into the refrigerant on the decrease in the heat removal of the cooled element. When evaluating the sensitivity of a device, the response time of the device must be taken into account.

In the General case, the criterion for assessing sensitivity is:

• 100 ° / o, where Q is the flow rate of the gas introduced into the refrigerant of the cooled element, l / h;

0y _L - refrigerant flow rate, l / h) x - delay time, s; T is the time constant, s.

According to the previously recorded criterion for evaluating the sensitivity of the device γ and the response time of the device when they change upwards by means of an on-line check with the subsequent correction of deviations from the norm, the operability of the burnout detection unit for cooled elements is constantly maintained at the required level.

IQ The experience of many years of operation of the device for detecting burnouts of air tuyeres (separation vessel) on blast furnaces / NLMZ shows that the insufficient readiness of the device to fix the gas phase when the integrity of the air tuyeres is disturbed more than once has a significant effect, leading to disruption of the course and thermal condition of the blast furnaces .

The implementation of the invention improves the quality of control, the reliability of the alarm when the integrity of the cooled element of the metallurgical furnace is violated, helps to prevent accidents in the 25 operation of the furnaces, as well as to use an effective device for monitoring the condition of the cooled element in the project stage.

Claims (1)

Complementary body 8 for opening the valve 9 and for switching on the electronic stopwatch 4. Partial opening of the valve 9 corresponds to gas (air) in the form of bubbles in the cooling system of element 1 (air lance) and gas (air) quantity flow meter. The actuator 8 of the valve 9 is controlled by the fixed opening of it / by the response of the pressure sensor 5; the time can be determined using the electronic stopwatch 4 and the minimum ratio of the gas flow to the refrigerant flow, respectively, of the flow meters 3 and in order to eliminate the effect of the flow rate of the refrigerant required for cooling the element, according to the evaluation criterion, the sensitivity of the device is taken as 100%, where Uf |, p is the minimum gas flow rate recorded at the device response threshold, l / h; - refrigerant consumption in test time, l / h. The accepted criterion for evaluating the sensitivity of the device. The lower numerical limit was chosen according to the results of examining various devices by the threshold of their operation. The upper limit is limited due to the influence of the introduced gas into the refrigerant on the decrease in heat removal of the cooled element. In evaluating the sensitivity of the device, it is necessary to take into account the response time of the device. In the general case, the criterion for evaluating the sensitivity is: “D.-e) 100 ° / o, where Q is the flow rate of the gas introduced into the refrigerant of the cooled element, l / h; - coolant flow rate, l / h} x - - latency, s; T - constant time, s. According to the previously established criterion for estimating the sensitivity of the device -jr and the device response time when they change to the direction by operative check followed by correction of deviations from the norm, the efficiency of the device for detecting burnouts of cooled electrons is constantly maintained at the required level. The experience of long-term operation of the device for detecting burn-in air tuyeres (separation vessel) on blast furnaces / NLMZ furnaces shows that the device’s inadequate readiness and fixation of the gas phase in violation of the integrity of the tuyeres lx connection repeatedly has a significant effect, leading to the disturbance of the course and thermal condition of blast furnaces. The implementation of the invention improves the quality of control, the reliability of alarm triggering in violation of the integrity of the cooled element of the metallurgical furnace, prevents emergencies in the operation of the furnaces, and also applies an effective device to monitor the state of the cooled element in the projecting stage. The invention of the method for determining the operating state of prog detection devices 4) of the cooled element of a metallurgical furnace, including fixing the gas phase in case of leakage of the cooled element, characterized in that, in order to provide an estimate of the sensitivity and reliability of burnout fixation by operative testing, coolant of the discharge pipe is cool -. of the attached element, gas is introduced in an amount of refrigerant consumption 1.03, 0%. Sources of information taken into account during the examination 1. USSR author's certificate 230841, cl. From 21 to 7/24, 1976.