Patent AT-409226-B (AT)
Title: Disposal of waste materials containing hydrocarbons e.g., sludge of roller scale uses a dryer with indirect heating to extract volatile components and cleaning of the exhaust gas to separate dust from it
Inventor: FLEISCHANDERL ALEXANDER DIPL I
IPC: B09B3/00
Filed: 2001-02-13
Granted: 2002-06-25
Abstract: Waste materials are placed in a moving dryer with indirect heating to release hydrocarbons and other volatile components. Targeted degrading of the hydrocarbons in the dryer is achieved at low temperatures together with chemical and/or radiation to combine hydrocarbon components with high and low molecular weights. Hydrocarbons and other volatile components are extracted from dryer by suction. In the disposal process for waste materials, containing hydrocarbons, the chemical action is by a feed of oxygen and especially mixtures of oxygen and an inert gas, or air enriched with oxygen; solid and/or liquid and/or gaseous peroxide or hyperoxide and especially hydrogen peroxide; ozone; a catalyst. At a given time point for the processing of the material in the dryer, the oxygen content of the drying environment is set at at least 20,8 vol.% in relation to the dry air, and preferably 25-50 vol.%. The radiation into the dryer is from a high energy source, and especially ultraviolet rays. Microwaves can also be used to provide the heating action. The heating at the dryer is applied indirectly at the drying chamber mantle or other sections of the dryer assembly. The waste material in the dryer is brought to a maximum temperature of 350 degreesC, and especially 300 degreesC or 270 degreesC. The waste processing is controlled according to process parameters in the dryer, and especially the intensity of its movement within the dryer and/or the heating power in the dryer and/or the temperature of the waste material and/or the quantitative feed of chemical/radiation agents for the degrading of the hydrocarbons. Before it is fed to the dryer, water is extracted mechanically from the waste and/or it is given an initial drying by chemical action and/or heat, and any exhaust gas is extracted. An initial heat drying action is in an additional dryer with indirect heating, to be treated at low temperatures to evaporate components with a low volatility and especially water, using temperatures of 40-200 degreesC and especially 90-110 degreesC. The exhaust gas is scrubbed to separate any dust, and is then burned off by heat or a catalyst, and the generated heat is used to heat one or more of the dryers used in the disposal operation, or for heating other disposal stages. The exhaust gas is monitored to measure the level of carbon monoxide and/or carbon dioxide and/or hydrogen and/or oxygen and/or hydrocarbons. The measured levels are used to control the waste disposal process parameters. The dryer is flushed with an inert gas, and especially nitrogen, to suppress any concentrations of oxygen and/or hydrogen in the dryer. An Independent claim is included for an assembly to dispose of waste materials containing hydrocarbons, with a system in the dryer (21) to decompose hydrocarbons which are difficult to evaporate with the readily volatile hydrocarbon components e.g. heavy hydrocarbon molecules among the light molecules. The system is independent of the dryer heating. Preferred Features: The system to break down the hydrocarbons uses a feed of oxygen and/or peroxide/hyperoxide and/or an ozone carrier into the drying chamber. It can also be an ultra violet radiator. The dryer has a feed for the delivery of a carrier gas, and especially an inert gas. The dryer has a system to agitate the waste material and/or the drying chamber is rotated. A dust extraction unit (27), with indirect heating, separates dust from the exhaust gas from the dryer. It has a number of channels (26, 29) with thermal insulation and/or additional heating, linked to the dryer at one side and to an exhaust gas treatment stage at the other side. One or more probes and/or sensors are at the exhaust gas channel and/or the dryer to monitor the gas temperature and/or its composition and/or the drying chamber temperature. A control sets the action of the heating system and/or the mechanism (23) to agitate the waste material in the dryer.