The Medical Waste Disposal Incinerator units shall be of Dual or Multiple Chamber type that thermally degrades combustible medical wastes of varying heat content using a two-stage or multiple stages combustion processes. That is first stage of thermal waste degradation in the primary chamber and second stage of smoke burning (flue gas treatment) in the secondary chamber. The waste burning process per cycle shall be fully automatic from start to finish. The waste incinerator unit shall consist of a primary chamber, secondary chamber, stack, combustion air blower, burners and controls as the main components.

Waste Incinerator Capacity

The waste incinerator units shall be designed to burn medical waste load of capacity 50 kg/hr with calorific values ranging from 2,300 kJ/kg to 30,000 kJ/kg at a designed thermal rate of 1,440,000 kJ/hr.

Method of Waste Charging

Waste shall be fed into the primary chamber manually, that is by hand. Semi-automatic or automatic feeding systems are not required.

Method of Burning

The primary and secondary burners shall be equipped with at least one fuel oil burner each. Waste shall be manually fed into primary chamber and heated to required ignition temperature of at least 600 degree Celsius. A controlled amount of air shall be admitted by combustion air blower to maintain the necessary reaction heat required for thermal degradation of waste. Smoke, ashes, volatile gases, etc generated from the primary chamber shall be effectively and efficiently ignited in the secondary chamber. Emission through the stack shall be within environmental standards.

Combustion Chambers

The internal lining for combustion chambers shall be made up of pre-determined thickness and high temperature stability insulation, high strength firebricks and castible refractory. The temperature rating for refractory shall be at least 1,500 degree Celsius. The casing of the chamber shall be constructed from high grade mild steel plate. Lifting devices such as eye bolts and lifting lugs shall be fitted as standard.

Doors

The doors shall be hinged on the right hand side and can be easily opened and closed. All doors shall be manually operated. Incinerator shall NOT incorporate automatic doors. All doors should be internally lined with pre-determined thickness insulation and refractory cement.

Stack

The stack shall be fabricated from pre-determined thickness stainless steel plate suitably flanged for connection.

Combustion Air Blower

A combustion air blower shall be of steel construction type with built-in air damper regulation shall be provided. The impeller shall be of the radial blade design and all rotating elements shall be dynamically balanced.

Burners

Burners fitted shall be of packaged fuel oil fired types. Primary chamber shall be fitted with an on/off type burner while the secondary chamber shall be fitted with a high/low type burner. The burners shall each have a maximum rating of300,000 kJ/hr.

Controls

A control system shall be provided to control all functions of the primary and secondary chambers including combustion air distribution and burner control. It shall comprise of PLC, temperature controllers, timers, relays and switches to provide automatic operation of the entire system. All switches and controls shall be mounted in an IP 55 rated control panel.

Power Supply

The incinerators shall have a power supply of 240/415 volts, 50 Hz AC. All electrical works shall conform to SAA Wiring Rules SA 3000 and be subject to PNG Power regulations.

Finish

All equipment shall be painted with a coat of zinc rich primer and two coats of high temperature heat resistant polyurethane type paint. All painted surfaces shall be prepared by either steel shot cleaning or sand blasting.

Identification and Name Plates

Identification and name plates containing the manufacturer’s name, model number, serial number, and other pertinent information shall be securely fastened to the unit in readily visible locations.

Fuel Type and Tank

All burners shall be fuel oil (diesel) fired. For all incinerators fitted with fuel oil (diesel) type burners, the bidder shall supply and install 1000 litres steel tank and all the necessary piping and fittings and initial supply of 1000 litres fuel oil. Where existing fuel is found to be still in good condition from site inspection, contractors must use existing tanks and therefore must clearly specify in their bids of such usage. The tank shall be positioned at least 2 meters above ground on steel frame next to the incinerator shed. Fuel delivery to incinerator burners shall be by gravity feed. The tank should be fitted with a drain plug as standard.