RU2844134C1 - Installation for catalytic afterburning of volatile compounds - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: invention relates to mechanical engineering, particularly, to catalytic afterburner intended for neutralization of volatile compounds in annealing and thermal stabilization of carbon-carbon materials in shaft furnace. Volatile compounds catalytic afterburning plant includes a burner installation unit, where a diesel burner is installed in the end part of the unit, gases from the shaft electric furnace are supplied to the upper part of the unit, besides, said unit incorporates hatch for inspection and cleaning, afterburner and finish filter arranged directly behind afterburner chamber and divided into three zones: inlet zone, where gases flow is distributed; zone of gases after purification, in which two cassettes are arranged in parallel, filled with mullite-silica fibre with density of not more than 150 kg/m³, which is treated with 10-15 % cobalt nitrate solution, and a gas cooling zone, which is located after the post-treatment zone, in which the temperature of the gases is reduced by admixing cold air therein, and then the purified and cooled gases are removed into the atmosphere by a fan.

EFFECT: possibility of carrying out thermal decontamination and filtration cleaning processes in one apparatus, which provides the maximum possible reduction of emissions of hazardous substances into the atmosphere, in particular soot and pitch sublimates by 80 %; benz(a)pyrene by 50 %.

1 cl, 2 dwg

Description

Field of technology

The invention relates to the field of mechanical engineering, namely to a catalytic afterburning unit designed to neutralize outgoing volatile compounds during the processes of roasting and thermal stabilization of carbon-carbon materials in a shaft electric furnace.

State of the art

A device for cleaning exhaust gases containing organic substances is known from the prior art, consisting of a gas neutralization and cleaning unit placed in a heat-insulated housing, dividing the internal cavity of the housing into a contaminated gas chamber, a working chamber and a purified gas chamber, the neutralization and cleaning unit consists of rows of shelves spaced apart from each other, on which cassettes with a catalyst are placed, the contaminated gas chamber is provided with a pipe for supplying contaminated gas, the purified gas chamber is provided with a gas duct for removing purified gas, characterized in that the ends of the shelves are alternately rigidly connected to each other by means of blind partitions, forming a meander-type structure, the cassettes with a catalyst are made of artificial mullite-containing fibrous material, the shelves are made in the form of grates and are placed in the direction of the gas flow, additionally containing a burner provided with a supply of natural gas and communicated with the contaminated gas chamber (see RU 2297273, (20.04.2007).

The disadvantages of this patent are the short length of the contaminated gas chamber and insufficient afterburning time for the decomposition and oxidation of harmful substances contained in the gases.

A gas emission afterburning unit for the production of hydrated cellulose carbon fiber materials is known from the prior art, comprising a cylindrical metal body lined on the inside with a refractory material with a reaction chamber equipped with a device for feeding afterburning gas emissions, a burner device and a gas outlet opening, wherein the metal body lined on the inside with a volume of 0.6 ^m3 , placed on a support element, is equipped with a burner with an adjustable natural gas supply system, with a pressure regulator and a stop valve, and also an air supply system made in the form of two channels directly through the burner into the working volume of the gas emission afterburning unit, wherein the air supply system to the burner is equipped with a temperature control sensor, an air supply channel damper for burning gas emissions, and the burner is equipped with a control system that ensures specified combustion process modes, wherein the gas emission afterburning unit is equipped with temperature monitoring and control means (see RU 166937, 20.12.2016).

The disadvantages of this patent are the lack of devices for capturing suspended substances contained in exhaust gases and suspended products of thermal decomposition and oxidation of harmful substances.

Disclosure of invention

The technical result of the claimed invention is the maximum possible reduction in emissions of harmful substances into the atmosphere, in particular, soot and pitch sublimates by 80%; benz(a)pyrene by 50%.

The above technical result is achieved by a catalytic afterburning unit for volatile compounds, which includes a heater installation unit, where a diesel burner is installed in the end part of the unit, gases from a shaft electric furnace are fed into the upper part of the unit, the unit also has a hatch for inspection and cleaning, an afterburning chamber and a final cleaning filter, which is located immediately behind the afterburning chamber and is conditionally divided into three zones: an input zone, where the gas flow is distributed; a gas after-treatment zone, in which two cassettes filled with mullite-siliceous fiber with a density of no more than 150 kg/ ^m3 , which is treated with a 10-15% solution of cobalt nitrate, are located in parallel, and a gas cooling zone, which is located behind the after-treatment zone, in which the temperature of the gases is reduced by mixing cold air into them, and then the purified and cooled gases are removed into the atmosphere by a fan.

Brief description of the drawings

Fig. 1 shows a diagram of the connection of the catalytic combustion unit for volatile compounds to the furnace.

Fig. 2 shows the external appearance of the installation for catalytic combustion of volatile compounds.

Implementation of the invention

The catalytic afterburning unit for volatile compounds consists of a block 7 with a burner (reactor) 4. A diesel burner WL 10/2-C (4) is installed at the end of the block. Gases from the shaft electric furnace 1 are fed to the upper part of the block. The temperature of the incoming gases is controlled by the readings of the thermocouple 8. The block also has a hatch 9 for inspection and cleaning. Thermal oxidation and decomposition of harmful substances begins in the block at a temperature of 700°C.

The afterburning chamber 3, together with the burner installation unit 4, at the set gas velocity, provides sufficient time for the decomposition and oxidation of harmful substances contained in the shaft furnace gases.

The final cleaning filter 10 with two cassettes 11 is located immediately behind the afterburning chamber 3 and is conditionally divided into three zones.

The hydraulic resistance of the cassettes is monitored by the readings of pressure sensors 12 before and after them.

The gas cooling zone is located behind the cassette installation zone. The gas temperature is reduced by mixing cold air 5 into them. The gas temperature in the cooling zone is controlled by the readings of thermocouples 8.

All elements of the installation are mounted on the installation frame 13. The installation of catalytic combustion of volatile compounds operates as follows.

The gases leaving the shaft electric furnace 1 are localized by a suction device 2 and sent to an installation with an afterburning chamber 3 and a diesel burner 4, there they undergo thermal cleaning and additional cleaning in a filter-catalyst, are cooled by the suction of cold air 5 and are removed into the atmosphere by a fan 6.

The installation for burning off volatile compounds can operate in two modes: “automatic” and “manual”.

In manual mode, the operator can control the operation of a separate mechanism (for example, turn on/off the fan, turn on/off the burner on the setup screen).

In automatic mode, when switched on, fan B1 is switched on, after reaching the working vacuum, the burner is started, then the temperature is raised to the value specified in the system settings. Temperature regulation is performed.

The main means of control, monitoring and adjustment of the installation of afterburning of volatile compounds is the operator panel. The operator panel receives and transmits data with the PR-102 controller to control the process.

The operator's workstation allows monitoring the state of the main process equipment, managing the operating modes of the controlled devices, individual actuators, keeping an accident log, and implementing operational control of emergency situations. The main working area of the screen shows a mnemonic diagram showing the controlled mechanisms: burner G1, exhaust hood B1 and filter, as well as sensors: reactor temperature, filter temperature, reactor vacuum, filter vacuum, fuel level sensor, as well as emergency indication of overheating and large differential on the filter. In the section indicating the operation of the system, you can also see the rotation speed of the exhaust hood B1 and overheating indication.

Claims (1)

A catalytic afterburning unit for volatile compounds, comprising a burner installation unit, where a diesel burner is installed in the end part of the unit, gases from a shaft electric furnace are fed to the upper part of the unit, the unit also has a hatch for inspection and cleaning, an afterburning chamber and a final cleaning filter, which is located immediately behind the afterburning chamber and is conditionally divided into three zones: an input zone, where the gas flow is distributed; a gas aftertreatment zone, in which two cassettes filled with mullite-siliceous fiber with a density of no more than 150 kg/ ^m3 , which is treated with a 10-15% solution of cobalt nitrate, are located in parallel, and a gas cooling zone, which is located behind the aftertreatment zone, in which the temperature of the gases is reduced by mixing cold air into them, and then the purified and cooled gases are removed into the atmosphere by a fan.