Air Pollution Control

What you have to know when applying blast gate damper

Introduction A damper is a device that adjusts the volume of airflow passing through the outlet, inlet or duct. By proper adjustment of all dampers in a system, a desired distribution of airflows in all the branches can be obtained, while minimizing the total airflow of the system to save energy— this is also termed air balancing. The most common dampers used in industrial ventilation and dust collection systems to balance airflows are slide gate dampers (The slide gate, also called “blast gate or cut-off” damper). In a slide gate damper (see Figure 1 of a straight flat slide gate damper), the slide is inserted perpendicular to the flow. Figure 1 A sample of straight flat slide gate damper As the gate is sliding into the duct, it will add resistance to the airflow and consequently reduce the volume of airflow, while increasing airflows in all other branches. Withdrawing the gate has the reverse effect on that branch and all the others in a system. Interaction between a fan ...

Push-pull ventilation system for open surface tank saves air flow

Three sections in this blog: Push-pull ventilation system and its advantages Disadvantages of general ventilation and side exhaust systems Methods to design a push-pull ventilation system Push-pull ventilation system and its advantages Open surface tanks used in industrial processes often need ventilating to remove harmful pollutants (vapors, fumes or aerosols) from the working environment. One method of removing pollutants is the so-called side push-pull ventilation system, in which a jet of air is blown (or pushed) from one side of the tank and collected (or pulled) by an exhaust hood on the opposite parallel side. This system is particularly useful for large tanks where access requirements preclude the use of an overhead canopy, and the size of the tank makes side (or rim) exhaust systems prohibitively expensive. Most agree that a push-pull ventilation system can yield air savings of up to 50% compared to a side suction only hood. An illustration of a push-pull system for an o...

The importance of knowing the dew-point of your airflow to avoid condensation inside of a baghouse

Introduction Most baghouse users are confused why their baghouses suffer moisture condensation problems in winter. This blog post tabulates the dew-point temperatures of the airflows with different Relative Humidity (RH) at three different airflow temperatures of 68 o F, 120 o F and 250 o F to show why moisture problems in baghouses or cartridge collectors occur in winter. Definitions of dew-point and Relative Humidity Dew-poin t is defined as the temperature at which condensation begins when the air is cooled at constant pressure. Relative Humidity (RH) expresses the moisture content of air as a percent of what it can hold when the air is saturated. The temperature of the airflow from a process will likely remain fairly constant and warm year round. However, a temperature differential (approximately 15 o F or more) between the dust collection point and the dust collector may indicate a potential condensation risk. Condensation in a baghouse causes problems When wate...

Airvate Blog

Search This Blog