By Joe Kiolbasa, Donaldson Torit Product Manager
Many industrial dust collectors use compressed air to clean and extend the life of their filters. This is typically accomplished using short pulses of compressed air inside of the individual bag filters or cartridge filters in order to blow or knock the dust off of the outside of the filter.
Those responsible for the operation of industrial dust collectors need to manage the compressed air supplied to the dust collector to ensure proper performance while controlling operational costs. Doing so helps reduce costly compressed air consumption, maximizes dust collector airflow performance, and reduces collector maintenance and down-time costs.
Clean-On-Demand vs. Continuous Cleaning
The first tip for controlling compressed air consumption for industrial dust collectors is to invest the extra money for quality on-demand-cleaning controls when buying your industrial dust collector.
Many collectors come standard with a control panel that continuously and automatically pulses filters with compressed air every 10 or 15 seconds — whether the filters need to be cleaned or not. This adds unnecessary costs for multiple reasons.
First, in most situations with continuous cleaning, more compressed air is being consumed than is needed to maintain stable collector operation. Depending on how a collector was initially sized and the volume of dust the collector is handling, it is likely that the frequency of cleaning (and the compressed air consumption) can be cut in half. In the case of a 50,000 cfm dust collector, a 50% reduction in pulsing could result in an annualized savings of over $1,300. This calculation assumes the collector is running two 8-hour shifts per day, 5 days per week. (See table below). This kind of savings could easily offset the investment of an on-demand controller in a month or two.
The second reason continuous cleaning increases cost is because excess pulse cleaning can fatigue filters which can shorten filter life. Shorter filter life means replacing filters more frequently resulting in higher replacement filter costs, increased labor costs to replace the filters, and increased downtime.
| Continuous Cleaning 10 Second Pulsing | On-Demand 50% Pulse Reduction - Full Load | On-Demand 50% Pulse Reduction - Partial Load | |
|---|---|---|---|
| BHP | 16.125 | 16.125 | 16.125 |
| Constant | 0.746 | 0.746 | 0.746 |
| Operating Hours | 4160 | 4160 | 4160 |
| Cost per kWh | $0.07 | $0.07 | $0.07 |
| % Time Fully Loaded | 1 | 0.5 | 0.5 |
| % Full Load BHP | 1 | 1 | 0.25 |
| Motor Efficiency | 0.95 | 0.95 | 0.9 |
| $3,687 | $1,844 | $487 |
$1,844 + $487 = $2,331
Annual Savings $3,687 - $2,331 = $1,356
Point of Use Control and Filtration
Once compressed air leaves the dryer, some air management needs tobe done before it reaches the dust collector. First, the pressure of the compressed air needs to be regulated so the collector is supplied with compressed air that meets the manufacturer’s specifications. Consult your collector manual for compressed air requirements for the dust collector. This is very important, as pulse cleaning with compressed air higher than the manufacturer’s recommendations can result in collector or filter damage. Therefore, a pressure regulator with gauge should be installed right next to the dust collector.
Next, a shut-off/lock-out valve should be installed so compressed air to the collector can be shut-off and locked-out prior to maintenance being performed on the collector.
Lastly, an automatic condensate valve and particulate filter should be installed before the collector to capture any remaining dust or condensation that may have been generated in the piping between the dryer and the dust collector. It should be noted that all point-of-use compressed air management devices mentioned in this section can be taken care of with one device that combines the regulator, gauge, shut-off/lock-out and final filtration.
In summary, compressed air is a critical utility for many industrial dust collection systems. By managing compressed air usage and condition (clean, dry compressed air), costs and collector maintenance can be reduced.
