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Types of Hazardous Waste Incinerators

Hazardous waste incinerators are used to burn certain types of garbage that cannot be simply thrown into a landfill. There are three types of incinerators: fixed hearth, rotary kiln and liquid injection. Each of them have specific applications for different kinds of waste. Learning about these incinerators is useful if you are concerned about public health and the environment.

  1. Fixed-Hearth Incincerators

    • Fixed-hearth incinerators are used for burning things like municipal and medical garbage. These devices can deal with both solids and liquids. The waste sits on top of a hearth, where fire is emitted from below. Ash is disposed of in a large container of water. The fires are maintained by natural gas or oil and can reach temperatures of 2,000 degrees Fahrenheit. Some combustors use large boilers to generate steam and create electricity.

    Rotary Kiln Incineration

    • Rotary kiln incinerators are used for solid and liquid industrial waste. The device uses a refractory system. A refractory is a large shell that rotates, tumbling and lifting the waste. Fuel is used to ignite the refuse, with flammable liquid waste also fueling the flames. Some liquid waste is pumped into the kiln incinerator with nozzles. Temperatures can range from 1,300 to 2,400 degrees Fahrenheit. An advantage of this system is that the constant rotation allows heat to be distributed evenly.

    Liquid Injection

    • Liquid injection is explicitly used for liquid waste from the agricultural and pharmaceutical industries. The waste is pumped into a cylindrical chamber, much like the rotary kiln. There is a main source of flame and smaller secondary nozzles that provide additional fire. This process effectively vaporizes and super-heats the waste to temperatures between 1,800 and 3,000 degrees Fahrenheit. Once the process is complete, it gives off exhaust in the form of carbon dioxide, water vapor, oxygen, nitrogen and other gases.

    Pollution Control

    • Common sense dictates that waste incinerators generate pollution. However, a lot of effort has been put into designing effective ways to reduce environmental impact. Liquid injection incinerators use devices called wet scrubbers, which filter harmful gases like sulfur dioxide and allow benign substances like oxygen and water vapor to escape. Incinerators that contain both solids and liquids use wet and dry scrubbers. Dry scrubbers are basically bag filters that capture solid exhaust waste, such as lead and mercury.

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