SU1739215A1 - Device to measure air temperature in plasmatron - Google Patents

Abstract

The invention allows a non-contact method to determine the temperature of the air flowing out of a nozzle of an electric arc preheater (plasmatron) in closed-type technology areas. To determine the temperature of heated air, the frequency of arc shunting at the output electrode is used and this frequency is used to calculate the temperature. To measure the frequency, the device is equipped with an electrostatic probe, the measuring electrode of which is placed at the front end of the tubular output electrode (anode), and the signal is removed from the divider, the input of which is connected to the electrostatic probe and the common bus connecting and output electrodes.

Description

The invention relates to a measuring and control technique and can be used in systems for diagnosing parameters of high-temperature gas flowing from an electric arc (plasma torch) nozzle.

The purpose of the invention is to reduce the influence of the device on the gas-dynamic structure of the flow.

The drawing shows a diagram of a device for measuring the temperature of air heated by a plasma torch.

The device contains a plasma torch 1 with a sectioned inter-electrode insert 2, consisting, for example, of conductive sections 3 and insulating strips 4. An electric arc 5 burns between the cathode 6 and the anode 7 of the plasma torch, the discharge current is maintained by a power source 8 connected to the cathode 6 and common bus respectively. The input of the voltage divider 9 is connected to the electrostatic probe 10 located on the anode section, the output through the potential isolation circuit 11 to the measuring unit 12, and the common terminal to the anode 7 and the common bus, the measuring unit 12 being in the form of a frequency meter.

The device works as follows.

Due to the non-self-sustained discharge between the arc 5 burning in the plasma torch 1 between cathode 6 and anode 7, and the electrostatic probe 10, the potential of probe 10 corresponds to the potential5 in this section, therefore the potential difference between the probe 10 and the common busbar corresponds to the voltage drop in the near-anode section arc 5 and this voltage oscillates with the frequency of shunting arc 5 at the anode 7. The signal in the form of alternating voltage, taken from the electrostatic probe 10, is attenuated by means of divider 9 to a level that ensures normal operation y from X |

with y

Yu

ate

The measuring unit 12, the potential isolation circuit 11 provides the electrical isolation of the circuits of the plasma torch 1 and the measuring unit 12, and also excludes its constant component from the signal. The temperature is determined by the measured frequency.

The proposed device provides non-contact measurement of the temperature of the air heated by the plasma torch, which reduces the effect of the device on the gas-dynamic structure of the flow in the discharge channel.

Claims (1)

The invention The device for measuring the temperature of the air in the plasma torch, containing five The main wire of which is connected to the output tubular anode, the front end of which is connected to the plasma torch cathode through the inter-electrode sectioned tubular insert, and the measuring unit whose input is connected to the output of the divider, in order to simplify the device while reducing the impact of the device gas-dynamic structure of the plasma torch flow; an electrostatic probe is inserted into the internal cavity of a sectioned tubular insert, the measuring electrode of which is placed at the front end of pipes atogo anode and is connected to the input of the divider, the measuring unit is designed as a frequency counter. Tl EG 17 15 I sixteen P 13 eleven