Normally the bag house bag cleaning operation is done by using reverse jet high-pressure air Pulsing Via Diaphragm type pulse valve. For this purpose a solid-state sequence controller is normally employed .A single controller of this type usually suffices for solenoid rows up to 40 numbers. Big Bag filters (more than 40 rows) are not easy to clean with single sequential controller so that Bag house delta “P” is maintained for efficient cleaning & to meet the emission norms.
For large no of solenoid rows following procedure is normally adhere to (on line modular cleaning).
No of sequence controller are grouped to perform such cleaning operation at a time. Such a On Line Cleaning for Big Bag house cleaning system is, called as module pulsing. (Implemented using grouping of bag rows & respective air headers).
For such case Module programming is executed in pairs of sequence controller simultaneously , firing air header solenoids. Like wise all total solenoids would be driven by respective allocated module controllers.
The supervisory controller for this purpose is called as Master controller.
• Which keeps the module sequence in line as per program. (Programmed in such a way that it sends signals to each module pair.)
• Generates On Time & Off Time (Interval times) Common clock pulse for all the modules
• Checks Delta “P” continuously during Module sequencing & pulsing operation If in case delta “P ”is high then substitutes interval time to crash mode interval time (normally 50% of interval time). This is crash mode system.

In this system no of dust collector modules (actually Bag houses) (see 3d drawing) maximum up to 8 numbers are allowed to collect dust By on line method. The cleaning of bags is done by closing inlet damper so that the said bag house unit stops collecting the dust & gets isolated from from others. When in isolation (off the line) its bags are cleaned by reverse air pulse jet of individual sequence timers. This is accomplished by master sequence controller. This sequence timer is also termed as Compartment sequence controller.

In reverse-air bag houses, the bags are fastened onto a cell plate at the bottom of the bag house and suspended from an adjustable hanger frame at the top. Dirty gas flow normally enters the bag house and passes through the bag from the inside, and the dust collects on the inside of the bags.

Reverse-air bag houses are compartmentalized to allow continuous operation. Before a cleaning cycle begins, filtration is stopped in the compartment to be cleaned. Bags are cleaned by injecting clean air into the dust collector in a reverse direction, which pressurizes the compartment. The pressure makes the bags collapse partially, causing the dust cake to crack and fall into the hopper below. At the end of the cleaning cycle, reverse airflow is discontinued, and the compartment is returned to the main stream.