SU538057A1 - Device for controlling the processes of chemical heat treatment - Google Patents

Description

one

The invention relates to the field of chemical-heat treatment of materials, in particular, to devices for automatically controlling the degree of dissociation of ammonia during nitriding.

A device for automatically controlling the degree of dissociation of ammonia 1 is known, the disadvantages of which are measurements of the degree of dissociation outside the saturation zone, the measurement resolution and low measurement accuracy.

The closest to the proposed invention in terms of its technical essence and the effect achieved is a device consisting of a sensor, a source of constant voltage, an amplifier and a self-tapping indicator, calibrated; in terms of the degree of dissociation of ammonia 2.

The disadvantages of such a device are indirect control of the degree of dissociation of ammonia from the gases leaving the furnace and low accuracy of control.

In order to measure the degree of dissociation of ammonia directly in the saturation zone, increasing the measurement accuracy). and continuous process control, the proposed device consists of a two-electrode sensor installed in the working volume of the furnace and reacting to a change in the electrical conductivity of the gas during thermal dissociation, a constant voltage source, a DC amplifier converting the output signal received from the atomic sensor into a unified signal direct current, and a self-recording indicator that records the amount of current in the sensor circuit, which is calibrated in terms of the degree of dissociation of ammonia.

The drawing shows a schematic diagram

devices for controlling the nitriding process.

The device consists of a two-ed.a.tro.a sensor, in which two electrodes are mounted; cathode and anode 1, 2, source of constant voltage 3, amplifier of direct current 4 and self-searching indicator 5. A two-electrode sensor is installed in the working zone of the muffle of the furnace 6. The device works in the following way. From DC source to electrodes

voltage is applied (15-70V), creating an electric field of low intensity in the interelectrode space.

When the temperature of nitriding ammonia under the action of thermal ionization decomposes into

ions of nitrogen and hydrogen which are electrically

The field creates an ionic current in the sensor circuit. The magnitude of this current is proportional to the degree of dissociation of ammonia. A signal containing information on the degree of dissociation (ionization) is amplified in a DC amplifier and recorded by a self-recording indicator on a chart tape.

Claims (2)

1.V. V. Dembrovsky, L. V. Beloruchev A device of the type SZPI-2 for automatic control of the degree of dissociation of ammonia in nitriding processes of metal products with ammonia diluted with nitrogen. Instruments and control systems, 1967, No. 4, pp. 22-23. 2. About. K. Kotov. Surface hardening of machine parts by chemistically-thermal methods, Mashinostroenie, M., 1969, pp. 147-155.