Waste is transported to the site in special containers and barrels placed in enclosed transport vehicles, or in tank truck. Solid wastes are poured into the incinerator’s solid waste container, or are collected in enclosed containers outside the reception area, whereas minced waste is collected in enclosed bunkers.
Healthcare wastes are transported in hermetically sealed (ADR certified) plastic containers equipped with a special, single-use, insoluble bond in closed transport vehicles. The sealed containers are transferred from the transport vehicle to a container of 770 l, which is lifted to the feed chute of a rotary kiln without being touched by human hand, and then through a double sluice into the furnace.
Paste-like waste and any other type of waste arriving in barrels, separated by their inflammability class, is collected in covered, chemically resistant, andesite-bottomed barrels equipped with a retention pit.
Liquid wastes are mixed based on their average calorific value, blending and chemical properties, and are collected in conical bottomed, cylindrical, rigid-topped steel storage tanks equipped with a stirrer and placed in retention pits.
Part of the waste consisting of mixed consistency materials is pre-treated before being fed into the rotary kiln.
The crushing of solid and paste-like wastes is carried out by a hydraulic shredder installed in the waste reception area. The crushed waste and the solid waste is loaded into a dispensing system by a mechanical grabber claw crane and then dosed to the rotary kiln. „A” and „B” class crushed and homogenized solid wastes are fed into the kiln from a separate bunker.(bunker4)
Incineration is planned on the basis of an optimization program, which allows us to determine the hourly waste streams of the various disposable and composite wastes, taking into account the heat load of the furnace.
In order to ensure the safe and perfect combustion of wastes that contain more than 1 % halogen, after the final combustion air has been blown in, the temperature of the combustion chamber must be at least 1100 oC.
The composition of the incinerated waste stream is maximized due to compliance with emission standards. The incineration is carried out in a rotary kiln with refractory lining at 1250 +/- 50 oC.
Depending on the adjustable rotational speed, the waste remains in the furnace for 30 to 90 minutes.
The thermal disposal of persistent substances is carried out in an afterburning chamber. Afterburning is optimized by the introduction of secondary air, which provides the right temperature and oxygen concentration. Temperature in the afterburning chamber is 1150 +/- 50 oC, the flue gas residence time is at least 2 seconds, and the average residence time is 7.1 seconds.
Flue gas from the afterburner enters the waste heat boiler where the recovered heat is used to produce steam. The steam exceeding the demand of our plant is sold, or, alternatively, is used to generate electricity.
Cleaning flue gas
The first step of the flue gas cleaning system is the hydrated lime absorber, which partly traps the acidic components. Dioxin, purine and other polluting compounds are bound in the reactor. This process is enhanced by slowing down the speed of the flue gas, and increasing the residence time.
Pre-treated flue gas loses its dust content in the dust abatement, so its dust content is low when it enters the scrubber. Built in between the dust abatement and the scrubber, the catalytic dioxin destroyer as well as the flue gas extraction fan provides constant depression in the combustion chamber and the flue gas cleaning equipment. The catalyst used for dioxin dehydration is vanadium pentoxide applied to sponge-like titanium dioxide, which helps the decomposition of dioxin and furan by oxidation of the dioxin and furan compounds in the flue gas. At the same time, the nitrogen oxide content of the flue gas also decreases.
Flue gases are exhausted to the outside air through a 70-m chimney.
The final stage of the flue gas cleaning system is the counter-current scrubber equipped with two-plane spray nozzles. Triggered by the hydrated lime, the washing liquor in the washing tower cools down to the saturation temperature of the water vapour and becomes saturated with water vapour, thus trapping the remaining impurities. Plaster sludge formed at the bottom of the washing-tower is deposited in the conical part, then drained with vacuum drain filter and collected in steel containers and then recycled into the rotary kiln. Purified flue gases are exhausted to the outside air through a 70-m chimney.
Flue gas monitoring and control
The composition of the flue gas is continually checked and registered according to European Union regulations. These measurements form an integral part of the supervisory system. Substances used or produced during the technological processes are continuously analysed by our laboratory.
Physical and chemical treatment processes
The physicochemical pre-treatment system aims to clean contaminated water containing various hazardous wastes from inorganic and organic pollutants. The small amounts of pollutants produced after the treatment is disposed of by incineration, and then the purified water is further treated in an industrial waste water treatment system.