Dust collection is a critical aspect of the manufacturing process. It keeps the environment clean, prevents health hazards, and minimizes equipment damage. Pulse Jet Dust Collectors are commonly used in industries to trap airborne dust particles. These collectors contain tubular filter bags topped with cone-shaped devices called venturis. But what are venturis and why are they used in filter cages?
What is Venturi for Filter Cage ?
In simple terms, a venturi is a cone-shaped device with a tapering constriction in the middle that causes an increase in the velocity of fluid flow and a corresponding decrease in fluid pressure. In a Pulse Jet Dust Collector, the venturi is located at the top of the filter bag and creates a negative pressure that pulls additional air down into the filter elements during pulsing.
Why to Use Venturi in Filter Cages?
The primary purpose of the venturi is to amplify the pulse cleaning of the filter bags. It creates a secondary airflow that is coupled to the compressed air pulse to enhance the amount of cleaning air for removing dust from the filter bags. Without the venturi, the volume of cleaning air may be insufficient for the amount of filter media that needs to be cleaned.
When longer filter bags or a large number of filter bags in a row are required, more cleaning air is needed. Compressed air is typically the costliest utility in the operation of a dust collection system. Hence, using a venturi can be an economical solution as it helps reduce the amount of compressed air required for cleaning.
Moreover, venturis also help air reach farther down the filter bag when longer bags are used. The venturi’s “converging-diverging” nozzle accomplishes this by creating a supersonic, accelerated airflow. A proper venturi includes both the converging and diverging sections and is not a simple funnel shape. This design converts pulse pressure into flow at the throat and then creates pressure regain in the diverging section so that compressed air is not lost exiting the venturi.
In conclusion, a venturi is a cone-shaped device that creates a secondary airflow for amplifying pulse cleaning of the filter bags in Pulse Jet Dust Collectors. It is economical when longer filter bags or a large number of filter bags in a row are required. Venturis help air reach farther down the filter bag when longer bags are used and are designed to convert pulse pressure into flow and create pressure regain in the diverging section. Overall, venturis are an essential component of filter cages in dust collection systems.
