Tag: waste

Technical Requirements for Medical Waste Incinerator

Incinerator

Diesel Fuel Incinerator

Incinerators in Fiji

IT is a daily occurrence to see black smoke being emitted from the chimneys at the Colonial War Memorial Hospital in Suva.

And following a recent letter to the editor from Satish Nakched, The Fiji Times followed up with an investigation into the smoke that poses an obstruction for the nearby residents of Waimanu Rd.

A common belief is that the smoke is a product from body parts being incinerated in the hospital.

Minister of Health and Medical Services, Jone Usamate clarified “the incinerator at CWM burns all clinical waste produced at the hospital”.

“The selection of type of wastes that should be incinerated follows international standards for infection control and disposal of clinical waste,” Mr Usamate said.

Clinical waste includes blood, tissue, human organs and other body parts.

“Incineration occurs in a controlled environment where items are incinerated at a very high temperature to kill all microorganisms in the waste.

“Incinerators are used in hospitals all over the world and are the chosen method to dispose of the waste as it keeps the chances of spreading disease and infection to a minimum.”

by: http://www.fijitimes.com/story.aspx?id=334379

Containerized Incinerators

Made-in-Vietnam waste incinerator shows its power

Made-in-Vietnam waste incinerator shows its power

VietNamNet Bridge – The waste incinerator of Vietnamese inventor Trinh Dinh Nang has been used in Bac Kan, Tuyen Quang and Thanh Hoa. But if it is used in other provinces as well, and therefore, can be produced on a large scale, the production costs will be much lower.

Nang’s waste incinerator was displayed at the Vietnam 2015 International Equipment and Technology Trade Fair, which caught the attention from many visitors.

He began working on such an incinerator some years ago, encouraged by the idea that his incinerator may help reduce the negative impact caused by hundreds of tons of medical waste.

In 2009, after successfully creating an incinerator, he filed a patent registration for his ‘hazardous waste incinerator’ to the Ministry of Science and Technology and got the patent in 2012.

Nang’s incinerator is a system which comprises a comprehensive combustion chamber which can burn waste in an uninterrupted process. The incinerator utilizes nano technology which disintegrates hazardous smoke, dust and frog.

The product is believed to have outstanding features which allow it to operate more effectively than products of the same kind.

Nang said that his waste incineration system is movable. The system can work properly if users have a small water tank and can treat the water.

He also said that all the incinerators available in Vietnam don’t have the pressure balance like his. The incinerator can burn waste, eject fire and not oil into burning materials. In the center of the combustion chamber, the temperature can reach 1,800oC.

With Nang’s incinerator, it doesn’t take much time to burn waste. The oil is durable, and there is no technical trouble with oil tubes.

The Ministry of Science and Technology (MST) has certified that Nang’s incinerator is the first medical waste incinerator in Vietnam which can satisfy the Ministry of Natural Resources and the Environment’s standards and it consumes the volume of fuel 80 percent lower than import products.

If the incinerator runs with diesel, it will need VND5,000 only to burn one kilo or waste. Meanwhile, the incinerators from US, Japan and UK would consume VND70,000-80,000 worth of fuel to burn a kilo of waste.

The outstanding feature of the made-in-Vietnam incinerator is that it can treat many kinds of waste, including domestic garbage and medical waste.

Director of the Bac Kan Science and Technology Department Do Tuan Khiem said the incinerator is a suitable choice for localities with moderate waste capacity. The machine is highly efficient and fuel-saving, which is big advantage in Vietnam’s conditions.

From: http://english.vietnamnet.vn/fms/science-it/145663/made-in-vietnam-waste-incinerator-shows-its-power.html

Waste Burning and Incineration Combustion Process

The combustion, or burning, of solid waste proceeds through a series of stages. Water is first driven from the unburned waste by heat produced from material burning nearby or from an auxiliary burner. As the waste heats up, carbon and other substances are released and converted into burnable gases. This is referred to as gasification. These gases are then able to mix with oxygen. If the temperature inside the burn chamber is high enough and maintained for a long enough period of time, the hot gases are completely converted into water vapour and carbon dioxide, which is then released into the air. If the temperature inside the burn chamber is not high enough and the burn time is too short, complete conversion of the burnable gases does not occur and visible smoke is released into the air.  Another result of burning at low temperatures is the creation of pollutants that were not originally present in the waste. This process is known as de novo synthesis. Dioxins, furans and other complex chemical pollutants can be formed through this process.

Ash produced from combustion takes the form of either fly ash or bottom ash.  Fly ash is the fine particles carried away in the form of smoke while bottom ash is the course non-combustible and unburned material that remains after the burn is complete. The type and amount of pollutants in the fly and bottom ash depend upon what waste is burned and completeness of the combustion process.

The completeness of combustion is determined by all of the following factors:

Temperature

The temperature generated is a function of the heating value of the waste and auxiliary fuel, incinerator or burn unit design, air supply and combustion control.  Complete combustion requires high temperatures. Generally, temperatures that exceed 650oC with a holding time of 1-2 seconds will cause complete combustion of most food and other common household waste.  Segregation of waste is required when using methods that don’t routinely achieve these temperatures. Dual chamber incinerators, which are designed to burn complex mixtures of waste, hazardous waste and biomedical waste, must provide a temperature higher than 1000oC and a holding time of at least one second to ensure complete combustion and minimize dioxin and furan emissions.  When these high temperatures and holding times are achieved, waste will be completely burned and ash, smoke and pollutant concentrations will be minimized.

Because exhaust gas temperatures vary from ambient to greater than 1000°C each time a batch waste incinerator is used, optional air pollution control systems with evaporative cooling towers and scrubbers are seldom recommended. However, it may be necessary to employ these systems with large continuous feed incinerators if additional cleaning of exhaust gas is required by regulatory authorities.

Holding Time

Complete combustion takes time.  Holding time, otherwise known as retention or residence time, is the length of time available to ensure the complete mixing of air and fuel, and thus the complete burning of waste. Low temperatures, low heating values of the waste and reduced turbulence require that the holding time be increased to complete the combustion process.

Turbulence

The turbulent mixing of burnable gases with sufficient oxygen is needed to promote good contact between the burning waste and incoming air. This will help in achieving the high temperatures at which waste can be completely burned. The amount of mixing is influenced by the shape and size of the burn chamber and how the air is injected. Passive under-fire ventilation achieved during open burning does not result in sufficient turbulence for the burning of a wide variety of waste.  Also, it is important not to overfill the burn chamber as airflow may be blocked and the amount of turbulence further reduced.  The more advanced incineration designs provide effective turbulence through the forced introduction of air directly into hot zones.

Composition of the Waste

The heating value, wetness and chemical properties of the waste affect the combustion process and the pollutants that are contained in the resulting smoke and ash. The higher the burn temperature, holding time and turbulence that are achieved, the less effect the composition of the waste has on completeness of the burn.

Environmental Guideline for the Burning and Incineration of Solid Waste

People living and working in Nunavut often have limited options available for cost effective and environmentally sound

management of household and other solid waste. The widespread presence of permafrost, lack of adequate cover material and

remote locations make open burning and incineration a common and widespread practice to reduce the volume of solid waste and

make it less of an attractant to wildlife.  A wide variety of combustion methods are used ranging from open burning on the

ground to high temperature dual-chamber commercial incinerators.  Generally, high temperature incinerators are more expensive

to purchase and operate and cause less pollution than do the less expensive and lower temperature methods.  However, high

temperature incinerators can safely dispose of a wider variety of waste than can the lower temperature open burning methods.

The Guideline for the Burning and Incineration of Solid Waste (the Guideline) is not intended to promote or endorse the

burning and incineration of solid waste. It is intended to be a resource for traditional, field and commercial camp

operators, communities and others considering burning and incineration as an element of their solid waste management program.

It examines waste burning and incineration methods that are used in Nunavut, their hazards and risks and outlines best

management practices that can reduce impacts on the environment, reduce human-wildlife interactions and ensure worker and

public health and safety. This Guideline does not address incineration of biomedical waste, hazardous waste and sewage

sludge. The management of these wastes requires specific equipment, operational controls and training that are beyond the

scope of the current document.

The Environmental Protection Act enables the Government of Nunavut to implement measures to preserve, protect and enhance the

quality of the environment. Section 2.2 of the Act provides the Minister with authority to develop, coordinate, and

administer the Guideline.

The Guideline is not an official statement of the law. For further information and guidance, the owner or person in charge,

management or control of a solid waste is encouraged to review all applicable legislation and consult the Department of

Environment, other regulatory agencies or qualified persons with expertise in the management of solid waste.