Venturi Scrubber Type System

Venturi Scrubber Type System

Suction Hood: Feeding of raw material is an intermittent process in Induction Furnace and at the time of completion of every heat, molten metal is tapped with tilting platform of furnace. Hence, it requires a Movable Hood System so as to facilitate slag removal, raw material (bulk) feeding and tilting of platform. Hoods are designed based on crucible diameter and optimum clearance of hood from furnace.

Ducts & Bends: Ducts and Bends are required to convey flue gases from point of suction to the chimney and connect various equipments like Hood, Spark Arrestor, Bag House, ID Fan and Chimney. Their sizes are based on flue gases volume & temperature.

Venturi Scrubber: In Venturi Scrubber the flue gases are passed through a converging section where velocity of the gases becomes very high. The water is sprayed on high velocity gases with high pressure at throat. The particles in the gases become wet. The purpose of throat is to provide the area with highest velocity and wet these particles so that they become heavy and easily removable. The gases are then passed through a diverging section where lot of energy is recovered which was lost in converging section. These gases are then passed through separator where wet dust particles are collected at bottom and clean gases are passed through mist eliminator followed by exit from scrubber.

Id Fan: ID Fan provides necessary driving force to convey flue gases from suction hood to top of the chimney. The volume sucked overcomes the total resistance offered by equipment and duct with the help of fluid horse power provided by ID Fan driven by suitable motor.

Stack (Chimney): The generated gases are passed through chimney of suitable height and diameter. The chimneys are provided and based on volume of flue gases temperature, dispersion desired, composition of gases and legal provisions for height.

Advantages & Disadvantages of Venturi Scrubber Type System

Advantages:

• Low Floor Area
• Can handle high temperature gases
• Suitable for gas pollution such as SO₂, NO_x etc.

Disadvantages:

• High Power Consumption to achieve desired standards

• Generates Water Pollution

• Material of Construction is prone to corrosion hence low life cycle

• Choking of pipe, Nozzle and duct (near scrubber) due to Wet condition

• High operation & maintenance cost

• Can remove submicron particle only with very high pressure drop leading to still high power consumption

• Material of Construction is prone to corrosion hence low life cycle

• Choking of pipe, Nozzle and duct (near scrubber) due to Wet condition

• Higher operation & maintenance cost

• Can remove submicron particle only with very high pressure drop leading to still higher power consumption

Discharge Characteristics as Per Norms

• Dust : Less than 150 mg/ Nm³

• Temp : Less than 80-100 C

• Gases : Traces of SO₂, NO_x, CO₂ CO

• Suction Efficiency : More than 90%