SU402790A1 - DEVICE FOR THE CONTROL OF THE PROCESS G ^ ORENIA - Google Patents

Description

one

The invention relates to a device for controlling the combustion process, on the basis of which a system of automatic control and regulation of fuel combustion can be created for the composition of flue gases in open-hearth furnaces, heating furnaces and other heat engineering units operating on liquid and gaseous tons.

Devices are known for controlling the combustion process of a fuel according to the composition of the flue gases, for example, by the O2 content in the combustion products or by the CO content.

However, poor mixing of fuel and air often leads to the simultaneous presence in the combustion products of both oxygen and combustible components, the ratio between which varies widely.

In order to continuously determine the amount of oxygen and combustible components that are jointly present in the combustion products, the proposed device is equipped with an additional recording device, which is connected to the measuring diagonal of one of the bridges depending on the sign of their difference signal through the signal contacts of the main registering device.

This makes it possible, in addition to information on the quantitative side of the combustion process, to obtain — excess oxygen or

components, additional information characterizing the qualitative side of combustion - the amount of oxygen and combustible

components that may be associated with improving the process of mixing fuel and air in a heat engineering unit.

Moreover, the information obtained is distinguished by an equally high degree of accuracy and gives

differentiated assessment of the combustion process.

The drawing shows a schematic diagram of the proposed device for controlling the combustion process.

The device comprises a central channel I with its subsequent branching into two parallel channels 2 and 3, in which fittings 4 and 5 are located for supplying additional reagents; in one of the channels - oxidizer

(oxygen or air), and in the other - a combustible gas (such as carbon monoxide). In parallel channels, reaction chambers 6 and 7 are located, in which compensatory and active thermal converters are installed.

elements 8 and 9, made in the form of an oxide-aluminum cylinder, in which platinum spirals of thermal resistances 10 are placed, which serve to heat the elements and measure their temperature.

Active and compensating thermoelements are made identical in their geometrical and electrothermal parameters and differ only in that the active elements are the carrier of a fine catalyst from platinum group metals, which ensures the flameless (heterogeneous) oxidation of the combustible gas on its surface. 9 reaction chambers 6 and 7 are included in the adjacent shoulders of measuring bridges 11 and 12, the remaining shoulders of which are recruited from resistors 13 and 14.

The adjustment of the zero level of the device is carried out using a null corrector 15.

Bridge measuring circuits 11 and 12 are connected differentially.

The difference signal of the bridges, proportional to the excess oxygen or combustible components of the combustion products, is measured by the main recording device 16, for example, an automatic electronic indicating potentiometer with a two-sided scale and recording on a tape chart fitted with a signaling device, contacts 17 and 18 of which are shown in the drawing. The setting of the alarm device corresponds to the zero level of the instrument scale.

The signal proportional to the amount of oxygen and combustible components present in the combustion products is measured by an additional recording device 19 (with a one-sided scale) connected to the bridge And through the contacts 17, and to the bridge 12 through the contacts 18 of the signaling device of the main recording device 16.

The device works as follows.

In the central channel 1 enters the analyzed sample of combustion products, which is divided into two parallel streams. By supplying additional reagents, therm, elements in the reaction chamber 6 are washed with a gas mixture with an excess of oxygen, thermoelements in the chamber 7, with an excess of carbon monoxide.

When the combustion products of combustible components (CO-4-H2) appear in the analyzed products, they are oxidized in the reaction chamber 6 on the catalytically active element 9, as a result of which additional heat is generated causing an increase in the resistance of the helix of its thermal resistance. At the same time, the balance of bridge 11 is disturbed and a potential difference appears in its measuring diagonal, the magnitude of which is proportional to the concentration of combustible combustion products.

When oxygen appears in the sample being analyzed, the temperature of the catalytically active element 9 of the reaction chamber 7 increases in the same way. In the measuring diagonal of bridge 12 a potential difference arises, the value of which is proportional to the oxygen content in the combustion products.

Since the bridge measuring circuits 11 and 12 are differentially connected, the signal measured by the main recording device 16 is proportional to the excess amount of oxygen or combustible components of the combustion products, depending on the sign of the difference signal of the bridges.

The signaling device of the main recording device 16 contains a microswitch and a cam. The indicator of the task of the signaling device is set at the zero mark of the instrument instrument. Depending on the direction of movement of the pointer of the instrument relative to the scale zero, the cam rotates to the right or to the left, while the contacts 17 and 18 of the microswitch are switched.

In the absence of excess oxygen or combustible components in the combustion products, as well as in the presence of excess oxygen (), the signal contacts 17 of the main recording device 16 are closed. The secondary recording device 19 is connected via contacts 17 to the measuring diagonal of the bridge 11, the signal of which is proportional to the concentration of combustible components co-present with oxygen in the combustion products being analyzed.

In the event that there is an excess amount of combustible components in the combustion products (), the difference signal of bridges 11 and 12 changes sign. The pointer of the device 16 is to the left of the zero mark of the scale, the contacts of the alarm device are switched: contacts 17 are open, and contacts 19 are closed. In addition, an additional recording device 19 is connected to the measuring bridge 12, the signal of which is proportional to the concentration of oxygen in the combustion products that is present together with the combustible components.

Thus, an additional recording device 19 measures the amount of oxygen and combustible components that are jointly present in the combustion products.

Subject invention

A device for controlling the combustion process, containing two parallel channels with fittings for supplying additional reagents, inside of which there are measuring catalytic elements connected in differential measuring circuits and a recording device, characterized in that, in order to continuously determine the number of absolute and excess quantities that are jointly present in the combustion products quantities of oxygen and combustible, the device is equipped with a signaling device installed at the zero point of the scale, connecting additional registering nribor to the measuring diagonal of one of the bridges depending on the sign of the differential sensor signal.