Incineration is a waste treatment process that involves the burning of solid waste in an incinerator. The burning process produces ash, heat and flue gases. Incinerators are very effective in reducing the volume of waste used for landfills and very popular in countries where land is scarce. The waste is usually compressed before being delivered to the incinerator. Previously incinerators were built without a separation chamber for cleaning flue gases generated during the incineration process. The flue gases released were considered harmful to workers and the environment. However new incinerator plants are being built with the separation chamber attached. Incinerators can also be used to generate electricity due to the tremendous amounts of energy released during the incineration process.
Incinerators are not only used for burning household and factory generated waste they are also used in hospitals to incinerate medical and laboratory waste which could be hazardous to the environment if not properly disposed of. Waste generated from hospitals are particularly hazardous because viral diseases could be spread to humans if the waste is not burned off at high temperatures to kill off the viruses.
Incinerators are also installed on large, ocean going ships which accommodate large crew and passengers with a lot of waste being generated.
A model incinerator is a vertical cyclo type with a rotating arm device to improve combustion and remove all solid waste. A sludge burner is incorporated to dispose of sewage, sludge and waste oil, the auxiliary oil burner is fitted to ignite the waste. Automatic control secure the igniter when the waste burns without it. Combustion air is furnished by a forced draft fan. The leading door to the waste is pneumatically operated and is interlocked with the burner and forced draft fan. Solid waste is fed into the incinerator in standard plastic bags about three at one time. A single close door button initiate automatic functioning of the incinerator. The waste is incinerated in 5-10 minutes. Liquid waste may be introduced through the liquid waste burner when the refractory is hot. Following its use, the incinerator is allowed to cool and ash and other non combustibles are removed by pulling out the ash slide bar. The rotating arm will scrub all the solid residue into the ash box from which it may be disposed. The control of an incinerator must be such that all expected areas of safety are covered. Exhaust gas temperate must be controlled to ensure that they are high enough to destroy odour and sterilize all residues but not so high as to melt glass or metal. Incinerator exhaust temperatures are considerably high so it is necessary to reduce them to acceptably high temperatures. This can best be achieved by introducing cold diluted air into the exhaust stream at a point as close to the incinerator discharge as possible.