7 Types of Incinerators You Must Know

In this blog, you will learn about different types of incinerators. As we know, incineration is one of the most widely used techniques for waste treatment. Other types of incinerators are used across the globe depending on availability and need. An incinerator is a large furnace for burning waste. Waste treatment efficiently reduces the volume of junk and its infectious hazards. It also prevents scavenging along with health and environmental hazards.

The first incinerator for waste disposal was built in Nottingham, U.K., in 1874. By Manlove, Alliott & Co. Ltd., and the design is patented by Alfred Fryer. Previously they were called destructors. Incineration plants are also known as waste-to-energy facilities. Incineration and other high-temperature waste treatment are defined as “thermal treatment.” To know more waste-to-energy facilities, connect with waste-to-energy consultants here.

Incineration is a high-temperature, dry oxidation process. It reduces organic and combustible waste to inorganic, incombustible matter. The procedure treats waste that cannot be recycled, reused, or disposed of in landfills. In this blog, I will cover the types of incinerators and their dust removal. For more details on disposal of organic waste, connect with organic waste experts on our platform.

Incinerators in India

Source: Downtoearth.com

According to a report following details were found on incineration plants in India. There are five working incineration plants in India. It has a cumulative installed capacity of 66.5 MSW and is currently operational/under trial run in the country.

S.No.	State	Name of city/town	Capacity (MW)
1	Maharashtra	Solapur	3.0
2	Delhi	Okhla	12.0
3	Delhi	Gazipur	16.0
4	Delhi	Narela-Bhawana	24.0
5	Madhya Pradesh	Jabalpur	11.5
	Total		66.5

The Ministry of Urban Development (MoUD) has received 53 proposals from 22 states with the potential to generate 405.3 MW of electricity under the Swachh Bharat Mission (SBM), which are currently under various stages of construction or tendering.

Types of Incinerators

There are various types of incinerator plant designs available. They can range from highly sophisticated, high-temperature operating plants to elementary combustion units at much lower temperatures. Three basic types of the incinerator are of interest for healthcare waste treatment. They are:

• Double-chamber pyrolytic incinerators: which may be primarily designed to burn infectious healthcare waste
• Single-chamber furnaces with static grate: these should be used only if pyrolytic incinerators are not affordable.
• Rotary kilns: operating at high temperatures, capable of causing the decomposition of genotoxic substances and heat-resistant chemicals.

Different types of incineration are in detail below.

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Burn Pile

It is the simplest and earliest type of waste disposal. They refer to a collection of combustible materials piled on open ground and set on fire. Combustion results in the reduction of the volume and mass of wastes. But this type of incineration has high pollution risks. Burn piles often result in incomplete combustion and therefore produce particulate pollution. These can and have an increased risk of uncontrolled fire spreading.

• Pyrolytic Chamber Incinerator

  This is also known as controlled air incineration or double-chamber incineration. It is the most reliable and commonly used treatment process for healthcare waste. A pyrolytic incinerator has a pyrolytic chamber and a post-combustion chamber. The pyrolytic chamber consists of a fuel burner used to start the process. 

  Pyrolytic incinerator: A type of incinerator

  In the pyrolytic chamber, waste is decomposed through oxygen deficient, medium-temperature (800– 900°C) combustion process. That produces solid ashes and gases, which, if treated properly, can be disposed of in the landfill.     

  Adequate waste type:

  • Infectious waste, sharps, and pathological waste

   — for efficient treatment and elimination of all pathogens.

  • Pharmaceutical and chemical residues

  — causes disintegration of most residues; however, only small amounts (e.g., 5% of total waste load) of these wastes should be incinerated in this process. 

  Inadequate Waste Type:

  • Non-risk healthcare waste; would waste the resource.
  • Genotoxic waste; treatment may not be efficient.
  • Radioactive waste; treatment does not affect radioactive properties and may disperse radiation.

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Waste that should not be Incinerated through this Technique

• Pressurized containers; may explode during incineration and cause damage to the equipment.
• Halogenated plastics such as PVC; exhaust gases may contain hydrochloric acids and dioxins.
• Wastes with high heavy-metal content; incineration will cause the emission of toxic metals (e.g., lead, cadmium, mercury) into the atmosphere.

The capacity of the incinerator ranges from 200kg/day to 10 tonnes/day. The capacity of the hospital incinerator is basically less than 1 ton/day. 

Standard Protocols for Operating Pyrolytic Incinerator:

• It should be operated and monitored by a well-trained technician. This will reduce maintenance costs and extend the life expectancy of the equipment. 
• A careful operational balance needs to be maintained between the two combustion chambers to maximize treatment efficiency and minimize the environmental impact of emissions.
• Cleaning of the combustion chambers and declogging of air inflows and fuel burners should be done periodically. 
• Operators in charge of loading waste and removing ashes should wear protective gear. 

 

Rotary Kilns 

A rotary kiln comprises a rotating oven and a post-combustion chamber. They are inclined at a slight angle vertically on their axis. It rotates 2 to 5 times per minute and is charged with waste at the top. The incineration temperature is 1200–1600°C, allowing the decomposition of very persistent chemicals such as PCBs. Ashes are moved out at the bottom end of the kiln. Produced gases in the kiln are heated to a high temperature to burn off gaseous organic compounds in the post-combustion chamber. 

Rotary kilns: A type of incinerator

Adequate Waste Type:  

• Infectious waste, sharps.
• Pathological waste.
• All chemical and pharmaceutical wastes, including cytotoxic waste. 

Inadequate Waste Type:

• Non-risk healthcare waste; would waste the resource.
• Radioactive waste; treatment does not affect radioactive properties and may disperse radiation.

Waste that should not be Incinerated through this Technique:

• Pressurized containers; may explode and cause damage to the equipment.
• Wastes with high heavy-metal content; cause the emission of toxic metals (e.g., lead, cadmium, mercury) into the atmosphere. 

The capacity of incineration ranges from 0.5 to 3 tonnes/hour. The incineration of chemical waste produces exhaust gases and ashes that may be loaded with toxic chemicals. So, ash treatment and exhaust gas treatment are required. It has a high consumption of energy. Equipment and operation are costly, so a highly trained professional is required.

Single Chamber Incinerator  

If pyrolytic incinerators are not affordable, single-chamber incinerators are used. Healthcare waste at those sites is incinerated in a static grate, single-chamber incinerator. It treats waste in batches. Incineration temperature ranges from 300–400°C. Operations like loading and de-ashing are performed manually. Air inflow is based on natural ventilation, sometimes maintained mechanically depending on the conditions. If the incinerator is properly operated, pathogens are annihilated. Ashes can consist of more than 3% of unburnt matter. It can be disposed of in a landfill. 

Adequate Waste Type: 

• Infectious waste, sharps
• Pathological waste
• General healthcare waste (similar to domestic refuse)

Inadequate Waste Type:

• Pharmaceutical and chemical residues; may exhaust gases mixed with toxins. Therefore, these wastes are less recommended for safety reasons. 
• Genotoxic waste; treatment by this means is not efficient.
• Radioactive waste has no effect on radioactive properties and may cause the dispersal of radioactivity.
• Inorganic compounds.
• Thermally resistant waste.

Waste that should not be Incinerated through this Technique:

• Pressurized containers; may explode and cause damage to the equipment.
• Wastes with high heavy-metal content; cause the emission of toxic metals (e.g., lead, cadmium, mercury) into the atmosphere.  

The capacity of incineration ranges from 100–200kg/day. This type of incinerator should not be set up because air pollution is already a major problem. Soots and slags should be removed regularly. Emissions usually include acid gases such as sulfur dioxide, hydrogen chloride, and hydrogen fluoride, black smoke, fly ash (particulates), carbon monoxide, nitrogen oxide, heavy metals, and volatile organic chemicals. To limit these emissions, the incinerator should be properly operated and carefully maintained.

 

 

Drum Incinerator and Brick Incinerator 

It’s the simplest type of single-chamber incinerator. It is only used as a last resort to incinerate waste as it causes air pollution. It is only appropriate in emergency conditions as during acute outbreaks of communicable diseases. Drum incinerators should be designed with proper airflow and ample fuel quantities. A 210-liter (55 US gallon) steel gallon can be used with both ends removed. It will allow one bag of waste each time.  

It can cause public nuisance, generating acrid odors and fumes that make eyes burn and water.

Fluidized bed

In this type of incinerator, a strong airflow is forced along the sandbed. Air penetrates through the sand to a point where it separates sand particles. The airflow starts with mixing and churning; it makes a fluidized bed. Then fuel and waste can be introduced. The sand particles with pre-treated waste are suspended in the air via airflow, which takes a fluid-like character.

Therefore, the bed is violently mixed and ruffled, which keeps small particles in the air. This method allows the mass of waste, fuel, and sand particles to the full course in the furnace. 

Specialized incinerators   

An example is furniture factory sawdust incinerators. They need much attention as they must handle many flammable materials and saw sin dust. Controlled burning back burns prevention systems are crucial as the dust can easily catch fire under the influence of LPG.

Conclusion

There are many types of incinerators available. They can greatly reduce the weight and volume of healthcare and municipal waste. They are the most primitive and effective waste-handling techniques. But as the saying goes, “every coin has two faces; one good and one bad.” Incineration also has good as well as bad effects on us and our environment.

The most concerning issue regarding incinerators is the emission of harmful gases into the atmosphere, which leads to an increase in air pollution, airborne diseases, cancer, skin problem, mist, etc. Fixing appropriate air filters and chimneys can reduce this problem.

Using the correct type of incinerator with appropriate technology is advisable. Waste management is very important right now. So, be a responsible and aware human of our planet. And let’s take a step toward a clean and safe future. If you want to say something about this subject, please let me know in the comments. I would love to hear from you. Please subscribe to us for more informational blogs. Connect with incineration consultants on our platform.