Technology
Principal :
The PG/PY -VS series of incinerators function under a combination of controlled heat and air. The three " T " S of combustion viz . Turbulence through air and temperature are controlled in such a way that the waste is first volatilized / gasified under the conditions of inadequate air andtemperature and then totally destoyed under conditions of adequate air and right temperature. The third "T", i.e. neccessary residence time in the secondary chamber is provided to achieve complete combustion and thus total incineration.
Thus the Waste is incinerated in two stages i.e. the primary chamber and the secondary combustion chamber which are positioned adjacent to each other. The flue gasses then pass through the high pressure drop venturi scrubber, droplet separator and are let out to atmosphere via ID fan and chimney. The primary combustion chamber operates under near pyrolytic condition wherein the wastes are decomposed and all volatiles are released. The sustrate remaining, gets converted into sterile ash. The volatiles released from primary combustion chamber are then completely burnt in the secondary combustion chamber under high temperature and excess air.
1) Primary Chamber
The primary chamber is lined with refractory and insulation bricks of IS-8 and IS-2042 standards. The air required for volatilization is supplied through an air duct and introduced through equally placed nozzels. Air flow is controlled with the help of air dampers provided. The primary chamber is fitted with a fuel oil burner which has neccessary instrumentation to function automatically. A forced draft fan is used to provide for combustion / volatilization air. The combustion air is controlled to have minimum turbulence, restricting ash fly off.The waste is fed through a charging door / DFDV and the ash is removed from the deashing door.
2) Secondary Chamber
The volatiles / gases emitted from the primary chamber pass through the neck to the secondary chamber which is also lined with refractory and insulation bricks / castables.Just before the flue gas enters the secondary the combustion air as per stoichiometric condition is mixed. The vapours are subjected to the right temperature / heat which is generated using an automatic fuel oil burner system. The secondary chamber is designed to ensure the flue gas residence time of one second.
The waste destroyed in the Pyrolytic has the following composition :
1) Volatile Matter.
2) Fixed Carbon
3) Moisture
4) Ash or Non-Combustibles.
The volatile matter has a low flash point and hence gets liberated in the primary combustion chamber. This is later burnt in secondary combustion chamber. Volatiles give rise to smell & smoke. These hence have to be burnt, at the high temperature in the secondary chamber. Volatiles are basically long chain Hydro-Corbons. Fixed corbon is the Non-Volatile portion of the waste and is completely incinerated in primary chamber only. The moisture present in the waste is evaporated in the primary chamber. This then passes through the secondary chamber and leaves the system as super heated water vapour.
Sterile ash and non-combustible material remained in the primary chamber. To prevent them from flying out along with the gases, non turbulent conditions are maintained in the primary chamber.Depending upon the type of waste destroyed in the incinerator the sterile ash contain ranges between 5-10 %. At the end of the burning operation we guarantee a similar quantity of sterile ash remaining as left over, proving that the destruction of the waste is complete.
The flue gases then pass through the downstream Air Pollution Control system. This system is designed to remove acidic pollutants and particulate matter present in the flue gases from incineration. This system comprises venturi scrubber, droplet separator followed by , ID fan and stack.
The flue gases from the incinerator are cooled to 850 Deg.C. and then sent to venturi scrubber. Venturi scrubber is a high energy device where (sub micronic) particulate matter as well as acidic pollutants are scrubbed. Here, the acidic gases are removed by absorption with caustic and the particulate by the inertial impaction energy. A high pressure drop (30 - 35 cm Wc) across the venturi scrubber, imparts sufficiently high energy which helps in atomizing the scrubbing liquid and thus trapping the particulate. In venturi, gases saturate due to evaporation of water vapour and thus cools. 5% caustic solution is used as scrubbing liquid to neutralize the S02 etc. present in flue gases.
The flue gases then enter tangentially into the droplet separator, which is of cyclonic type. By the action of centrifugal force, the larger droplets present in flue gases settles down. This helps in protecting the impeller of the ID far,.
The ID fan maintains the balance draft and draws out the clean gases into the atmosphere through a 30m high stack.
3) System of Venturi Scrubbing
The flue gas from the educator passes through the down stream venturi scrubbing system is designed to remove particulate matter & pollutants of acidic present in the flue gas generated during incineration. Venturi scrubbing system comprises venturi scrubber, droplet separator & induced draft fan which have been made of corrosion resistant material. It is a high energy device through which micronic particulate matters as well as acidic pollutants are scrubbed. With caustic, the acidic components are removed by absorption. Due to high pressure drop, the venture scrubber imports sufficient energy helping atomizing the scrubbing liquid & trapping minute particulates.
The flue gas enters tangentically into the cyclonic type of droplet separator. The larger droplets present in the flue gas are removed by the action of centrifugal force which helps in protecting impeller of ID fan. The ID fan maintains the negative draft emitting out the clean gas into the atmosphere through a stack.
Advantage of choosing BEPPL
1) Facility with environmentally sound management.
2) Clearance from MOEF and Aithorised by KSPCB.
3) Dedicated vehicles to transport Hazardous Waste.
4) Environmentally friendly technology.
5) Facility hazardous waste management system.