RU81292U1 - INSTALLATION FOR THERMAL DESTRUCTION OF SOLID WASTE CONTAINING RADIOACTIVE COMPONENTS - Google Patents

Abstract

The invention relates to the field of disposal of organo-waste.

The technical problem to be solved: thermal, environmentally friendly destruction of solid waste contaminated with radioactive components (protective clothing, filters, etc.), increasing the unit's shift capacity.

Method for solving the technical problem: Preliminary thermal decomposition (pyrolysis) of waste in an oxygen-free atmosphere, controlled air supply to ensure optimal combustion conditions of gaseous pyrolysis products, accelerated heating of the installation, purification of the working fluid in the gas purification system without stopping the process, loading operations in an inert gas atmosphere. Installation for the thermal destruction of solid waste contaminated with radioactive components contains a thermoreactor, including a heating chamber with an autonomous burner, a thermal decomposition chamber equipped with a device for loading waste with an inert gas supply system, a means for unloading the coke-ash residue, a mixing device, a channel for outputting gaseous products thermal decomposition and a heating casing. The thermoreactor is equipped with a catalytic afterburner, a gas distributor, a vertical cyclone furnace with a afterburner, equipped with a burner and an air duct with a pressure fan with adjustable capacity, a heat exchanger, a gas purification system, a smoke exhauster and a chimney. The heating chamber is equipped with a grate, an ash residue withdrawal system and an air supply. The gas cleaning system contains a scrubber, a container for fresh working fluid, a container for purified liquid, a filter, pumps, pipelines and control valves. The loading device and the system for removing ash and sludge residues are equipped with glove boxes.

Description

The invention relates to the field of disposal of solid waste contaminated with radioactive components (clothing, filters, respirators, rubber gloves, aprons, plastic compound, PVC fabric, etc.).

Installation for the thermal destruction of solid waste contaminated with radioactive components contains a thermoreactor, including a heating chamber with an autonomous burner, a thermal decomposition chamber equipped with a device for loading waste with an inert gas supply system, a means for unloading the coke-ash residue, a mixing device, a channel for outputting gaseous products thermal decomposition and a heating casing. The thermoreactor is equipped with a catalytic afterburner, a gas distributor, a vertical cyclone furnace with a afterburner, equipped with a burner and an air duct with a pressure fan with adjustable capacity, a heat exchanger, a gas purification system, a vacuum pump and a chimney. The heating chamber is equipped with a grate, an ash residue withdrawal system and an air supply. The gas cleaning system contains a scrubber, a container for fresh working fluid, a container for purified liquid, a filter, pumps, pipelines and control valves. The loading device and the system for removing ash and sludge residues are equipped with glove boxes.

A known installation for processing radioactive waste containing a device for supplying an oxidizing agent, a shaft furnace, a melting unit and a gas purification system [1]. The disadvantage of the installation is that since the waste is burned due to the operation of the burner with excess air and the supply of flue gases to the material layer, the entire process takes place under excessive pressure and there is the possibility of uncontrolled release of radioactive materials into the atmosphere. Another disadvantage is that, since the irrigated scrubber, the liquid tank and the heat exchanger are connected in a closed circulation circuit, where the heat exchanger is used as a heating unit, the working fluid cannot be cleaned directly during operation of the installation.

Closest to the claimed utility model for the design of the main equipment, the principle of operation and the achieved result is a facility for the disposal of waste contaminated with radioactive components [2], containing

a thermal decomposition chamber equipped with a loading device, means for unloading the coke ash residue and a mixing device, a vertical cyclone furnace with an afterburner equipped with a burner in the upper part, a gas distribution device, a heating chamber with a grate and an ash residue removal system in it, a catalytic afterburner, a heat exchanger , gas cleaning system and smoke exhaust. The gas treatment system is equipped with means for collecting and preparing the collected sludge for re-pyrolysis. The ash and sludge removal systems are equipped with glove boxes.

The disadvantage of this installation is the large expenditure of time for heating it from a cold state to operating temperature, which is carried out only by the heat of the flue gases obtained from burning external fuel in a relatively low-power burner of a cyclone furnace, the main technological purpose of which is to maintain a standby torch. The disadvantage of the installation is the difficulty of maintaining the optimal ratio of air / ASG necessary for high-quality combustion of a gas-vapor mixture (ASG) entering the cyclone furnace burner, since the amount of ASG is periodically changed according to the waste loading cycles, and the amount of air supplied to the combustion is ensured only by rarefaction in the air intake duct burner device created by a smoke exhauster operating in a continuous mode. However, with an increase in the volume of flue gases due to the combustion of gaseous products after the beginning of the pyrolysis of the next portion of waste, the vacuum decreases and, accordingly, the flow of air into the burner device decreases exactly when, on the contrary, its increase is necessary.

The disadvantage of this device is the possibility of suction of air into the thermal decomposition chamber (KTR) through leaks of the loading device, which can lead to a sharp ignition (popping) of ASG in KTR.

The disadvantage of this device is the inability to clean the contaminated liquid in the wet gas cleaning system directly during operation of the installation.

The aim of this invention is to increase the shift capacity of the installation by reducing the time of its heating, providing optimal conditions for high-quality combustion of a gas-vapor mixture, eliminating the possibility of air entering the thermal decomposition chamber through a loading device and providing the possibility of cleaning the contaminated working fluid in the gas purification system directly during operation of the installation .

These technical results are achieved due to the fact that the heating chamber of the installation is equipped with an autonomous burner device located in

In the immediate vicinity of the thermal decomposition chamber, the air duct of the cyclone furnace burner is equipped with a pressure-controlled fan with an adjustable capacity, the loading device is equipped with an inert gas supply system, and the wet gas scrubber is equipped with a hydraulic system containing containers for fresh and purified working fluid solutions, a filter, and pipelines with fittings.

The supply of the heating chamber with an autonomous burner device located in the immediate vicinity of the thermal decomposition chamber can significantly increase the intensity of its heating, both by increasing the temperature of the flue gases entering the KTP chimneys almost directly from the burner and by direct radiation from the torch.

The supply of the air duct of the burner of the cyclone furnace with a pressure fan with an adjustable capacity makes it possible to supply air to the burner in the optimum quantity for high-quality combustion of the gas-vapor mixture, regardless of the general hydraulic mode of operation of the installation, determined by the operation of the smoke exhaust. Autonomous air supply allows to increase the vacuum in the thermal decomposition chamber due to ejection and to burn gaseous pyrolysis products under optimal conditions by improving the quality of mixing and increasing the residence time of the combustion products in the combustion chamber at high temperatures, which contributes to the process of burning out harmful components and provides an environmentally friendly composition gas emissions.

Providing the loading device with an inert gas (or water vapor) supply system allows it to create a slight overpressure in it, which prevents atmospheric air from entering the thermal decomposition chamber through the loading device, which is unacceptable by technological conditions.

Providing the wet scrubber with a hydraulic system containing containers for fresh and purified solutions of the working fluid, a filter, pumping pumps and pipelines with fittings allows cleaning the contaminated working fluid directly during operation of the unit without stopping, which increases its shift capacity.

A useful model of a plant for the thermal destruction of solid waste containing radioactive components is illustrated by the drawings in Fig. 1 where in Fig. 1 a diagram of a longitudinal section of the plant is shown, and in Fig. 2 is a diagram of a hydraulic system for purifying a working fluid.

The installation contains a thermoreactor-1, including a heating chamber-2 with an autonomous burner-23, a thermal decomposition chamber-3 located in it, equipped with a means for loading waste-4 with an inert gas supply system-24 and a means for unloading coke-ash residue-5, a channel for outputting gaseous products of thermal decomposition-6 and a heating casing-7. The thermoreactor is equipped with a catalytic afterburner-8, a gas distributor-13, a vertical cyclone furnace-14 with a afterburner-17, equipped with a burner-15 and an air duct-16 with a pressure fan-25, a heat exchanger-9, a gas purification system-10, a smoke exhauster-11 and a smoke pipe-12. The gas distributor is connected to a catalytic afterburner-13, to the output channel of the upper part of the afterburner and to the output channel-18 of the heating casing-7. The lower part of the cyclone furnace is connected to the lower part of the afterburner, equipped with an air supply-19. The heating chamber is equipped with a grate-20 grill, ash residue withdrawal system-21 and air supply-19. The unit is equipped with a mixing device-22. The gas cleaning system-26 consists of a scrubber-27, a container for fresh working fluid-28, a container for purified liquid-29, filter-30, pumps-31, pipelines-32 and control valves-33. The loading device and means for unloading the coke ash residue, dust and sludge are equipped with glove boxes, which are under vacuum, all air intake channels of the installation are equipped with filters with check valves, eliminating the possibility of radioactive components entering the atmosphere during an abnormal increase in pressure (cotton), the gas cleaning system is equipped with means for collection and preparation of trapped sludge for re-pyrolysis

Installation works as follows:

The installation is heated by turning on the burners-15 and 23. Due to the radiation of the torch and the heat of the flue gases, the thermal decomposition chamber is heated to an operating temperature of 700-800 ° C. A portion of the waste is placed in the loading device-4, which is constantly washed with inert gas coming from the system-24. By means of a pusher, the waste is transferred to the thermal decomposition chamber (KTR) -Z. The waste is heated from the walls of the chamber to a temperature of 650-700 ° C and during heating they decompose without oxygen (pyrolysis), resulting in approximately 60-70% of gaseous combustible gases and 30-40% of coke-ash residue. The gaseous products of pyrolysis due to the draft of the smoke exhauster-11 enter the cyclone furnace-14, where they are mixed with the air supplied by the pressure fan-25. Air-gas mixture ignites from the torch

burner and burns in a rotating gas flow, which, due to high turbulence, high relative speeds and residence time, provides high-quality combustion of combustible components of pyrolysis gas and solid particles (dust collector). The resulting flue gases are subsequently sucked through the cartridge of the catalytic afterburner-8, where the low-temperature oxidation of the residues of organic compounds takes place, the heat exchanger-9, where the temperature of the gases is reduced to the level of 150-120 ° C and enters the gas treatment system-10. In the gas purification system, first the flue gases are cleaned of dust in a “dry” cyclone, and then they are washed with liquid in a “wet” scrubber-27. The purified flue gases enter the exhaust fan-11 and are emitted into the atmosphere. Dust is unloaded from the cyclone as it accumulates in a sealed container through the glove box under vacuum. Disposal of this dust is carried out using special technology. The collection and unloading of sludge from the scrubber is done through a glove box in textile or plastic bags, with which the sludge is again pyrolyzed in the thermal decomposition chamber. The coke-ash residue formed as a result of pyrolysis (KZO) is unloaded from KTP-3 onto the grate-20 as it accumulates, under which atmospheric air enters due to the exhaust fan draft. The ash remaining after combustion of the organic component of the KZO is removed from under the grates by a special transport device-21 and through the glove box, which is under vacuum, is discharged into a sealed container. Ash utilization is carried out using special technology. In the process of continuous operation of the installation, the contaminated working solution is cleaned, for which it is supplied from the scrubber-27 by one of the pumps-31 to the filter-30, from where, after cleaning, it enters the tank-29 and then is again fed into the scrubber by the other pump. If necessary, contaminated working fluid can be completely removed from the system and replaced with fresh fluid supplied by the pump from tank-28.

The operation of the entire process chain under the vacuum created by the exhaust fan located at the outlet of the installation ensures that radioactive components cannot escape into the atmosphere during the process, and the equipment of all air intake channels with filters with check valves eliminates the possibility of radioactive components entering the atmosphere during an abnormal increase in pressure (cotton) in installation. Waste loading, unloading of coke ash residue, removal of sludge from the scrubber and dust from the gas treatment system through glove boxes located under vacuum eliminates the possibility of radioactive components entering the atmosphere during loading and unloading operations.

Repeated pyrolysis of sludge and afterburning of coke residue allows the bulk of the initial radioactivity of the waste to be concentrated in the ash.

The supply of the heating chamber with an autonomous burner device located in the immediate vicinity of the thermal decomposition chamber allows to significantly increase the intensity of its heating, both by increasing the temperature of the flue gases entering the KTP chimneys almost directly from the burner, and by direct radiation from the torch.

Autonomous controlled air supply allows you to burn gaseous pyrolysis products under optimal conditions by improving the quality of mixing and increasing the residence time of the combustion products in the furnace volume at high temperatures, which contributes to the process of burning out harmful components and provides an environmentally friendly composition of gas emissions.

Providing the wet gas scrubber with an autonomous, hydraulic system containing containers for fresh and cleaned working fluid, a filter, pumps and piping with fittings allows cleaning of the working fluid without stopping the process.

Thus, the combination of these essential features provides the possibility of environmentally friendly thermal destruction of organo-containing solid waste containing radioactive components, and allows you to increase the shift capacity of the installation.

Information sources:

1.http // www. sciteclibrary.ru/eng/catalog/pages/3320.html, 01/13/05. Patent number: model-22837 dated July 9, 2002 Markelov N.I. and other installation for the processing of radioactive waste.

2. Patent for utility model of the Russian Federation No. 42289 "Installation for the disposal of solid waste."

Claims (1)

Installation for the thermal destruction of solid waste contaminated with radioactive components, containing a thermal decomposition chamber equipped with a loading device, a mixing device and means for unloading the coke ash residue, a vertical cyclone furnace with an afterburner, equipped with a burner in the upper part, a heating chamber with a system in it afterburning and withdrawal of coke ash residue, gas distributor, catalytic afterburner, heat exchanger, gas purification system and smoke exhaust, characterized in that the heating chamber is equipped with an autonomous burner device located in the immediate vicinity of the thermal decomposition chamber, the air duct of the burner of the cyclone furnace is equipped with a pressure fan with adjustable capacity, the loading device is equipped with an inert gas supply system, and the wet gas scrubber is equipped with a hydraulic system, Containers for fresh and cleaned working fluid, filter, pumps and piping with fittings.