SU375449A1 - ALL-UNION - Google Patents

Description

one

The invention relates to the field of automatic control of the combustion mode of boilers when solid fuel is burned in them.

Systems are known for automatically determining the content of combustible in fly ash when burning pulverized fuel in the combustion chamber of a boiler unit, which contain a gas intake device connected to a cyclone and a measuring capacitor connected to a capacitance meter.

The purpose of the invention is to provide a constant ash density, eliminate swirl flow, arch formation, adhesion, and eliminate the influence on the accuracy of moisture measurement.

The goal is achieved by the fact that a disk feeder is installed at the exit of the cyclone, and the condenser is made in the form of a vertically positioned channel, for example, a plane-parallel channel, for passing through it a dry ash sample, and also the fact that the cyclone is equipped with a nozzle 2-0.3 lengths of the cyclone. In addition, an insert with a radius equal to the internal radius of the nozzle is installed inside the nozzle, the gas intake device is installed in the temperature zone of 250-300 ° C, and the cyclone and nozzle are equipped with a heater.

The system is shown in the drawing.

The system for automatic measurement of the current values of the content of combustible in fly ash consists of primary device A and secondary device B.

Primary device A is installed in close proximity to the bottom of the boiler unit and is designed for continuous extraction from boiler duct 1 of representative content of combustible ash, continuous feed to measuring element 2 to form ash samples in it and continuously remove it.

The primary device contains a slot-type intake device of type 3, designed to extract the flue gas stream from the boiler duct with the ash contained in the cyclone 4, separating the ash from the associated gases, which is heated by steam with a temperature of 250-300 ° C passing through the coils 5 and is well isolated from the environment by thermal insulation 6 for supplying a dry sample to measuring element 2; an ejector 7, which serves as a selection booster and through which the associated gases are discharged into the gas duct / boiler unit; connective

pipe 8, which prevents the turbulence of the ash separated by the cyclone; measuring device 9, which includes a measuring element (capacitor) 2, consisting of a tube / (located vertically, electrodes 11, the upper disk 12 and

the lower disk 13, located on the same shaft and driven in rotation by the electric drive 14, through the gearbox 15, which together with the upper knife 16 and the lower knife 17 serve to evenly fill the ash and to remove it evenly from the measuring element 2.

In order to prevent both arising from the outflow from the cyclone and adhesion inside the outlet nozzle 8, the insert 18 rotates on one shaft with disks 12 and 13 whose width is equal to the inner radius of the outlet nozzle.

To remove waste ash, a canyon-pump 19 with an electric drive 20 serves, which, in addition, releases pressure upon the discharge of waste ash 21 by a canyon-pump 19 into a gas duct / boiler unit or prevents the ash from moistening in the primary device when the ash is dumped by a canyon pump 19 in the water wash 22.

Secondary device B consists of a capacitance meter 23, a measuring capacitance of the measuring element 2 with ash, and a recorder 24 of the content of combustible in ash, calibrated in% C {.

The ash removal device 3 is embedded in the wall of the duct 1 of the boiler unit and connected to the inlet 25 of the cyclone 4. The output gas nozzle 26 of the cyclone 4 is connected to the ejector 7, built into the wall of the duct 1 of the boiler.

The lower ash pipe 27 of the cyclone 4 is connected to the outlet pipe 8, which, in turn, is connected to the housing of the measuring device 9. The hopper 28 of the measuring device 9 is connected to the canyon pump 19, which is located under the housing of the measuring device 9 .

Pipeline discharge of waste ash after the canyon-pump 19 may be embedded in the duct 1 of the boiler unit 21 or in the water wash 22.

The electrodes of the capacitor // measuring element 2 are connected by a high-frequency cable 29 to a capacitance meter 23 of the secondary device B, remote no more than 10-15 meters from the primary device A. The capacitance meter 23 is connected to a recorder 24 of the secondary device B located within the boiler shop.

The ash deposited in the cyclone 4 flows through the connecting pipe 8, in which the insert 18 rotates connected to the shaft of the disks 12 and 13 and prevents adhesion on the upper disk 12 of the measuring device 9 of the primary device A, which rotates at a speed of 2-10 rpm . The ash, hitting the upper disk 12, is cleaned from the disk 12 with the help of the knife 16 and enters the measuring element 2. In order for the ash not to spill past the measuring element 2, it is possible to move it slightly relative to the knife 16.

The gap between the lower disk 13 and the measuring element 2 determines the flow of ash through the measuring element 2. The adjustment of the gap and, therefore, the consumption of ash is made by moving the lower disk 13 relative to the measuring element 2.

Ash falling onto the lower disk 13 is cleared from it by means of a knife 17 and enters the ash removal device 19.

Since the amount of ash entering the device A from the cyclone 4 must exceed the ash consumption through the measuring element 2, provided that the measuring element 2 is constantly filled with ash, the excess ash, mine measuring element 2, falls from the upper disk 12 directly onto the lower disk. 13 and together with the waste ash is removed from instrument A.

During the passage of the bulk body formed by the free filling of ash coming from the upper disk 12 through the measuring capacitor (electrodes) // primary device A, the capacitance of the measuring capacitor 11c is continuously measured by the secondary device B of the system, where the signal is proportional to the measured capacitance of the measuring capacitor 11, which means the content of combustible in the ash, is fed to the recorder 24, graduated

in% C1

Subject invention

Claims (4)

1. The system for automatically determining the content of combustible in fly ash when burning pulverized fuel in the combustion chamber of the boiler, containing a gas intake device connected to a cyclone, and a measuring capacitor connected to a capacitance meter, which in order to ensure a constant ash density, A double disk feeder is installed at the exit of the cyclone, and the condenser is made in the form of a vertically arranged channel, for example, a plane-parallel one, for passing a bulk ash sample through it. 2. The system according to claim 1, characterized in that, in order to eliminate the flow turbulence, the cyclone is provided with a nozzle in the form of a nozzle 0.2-0.3 in length of the cyclone length. 3. The system according to claim 2, characterized in that, in order to eliminate arching and the phenomenon of adhesion, an insert with a radius equal to the inner radius of the nozzle is installed inside the nozzle. 4. The system of PP. 1-3, characterized in that, in order to eliminate the influence of the accuracy of moisture measurement, the gas intake device is installed in the temperature range of 250-300 ° C, and the cyclone and the nozzle are equipped with a heater. 1: (OI shch1 g gases