The Truth about Differential Pressure Gauges and Baghouse Monitoring
I can’t tell you how many times I have heard this line – “I am only required to monitor the differential pressure on my baghouses – that’s what my permit says…” This has caused the perception that a DP gauge can be used to detect leaks in a baghouse and satisfy baghouse monitoring requirements. Well – this can be true – but only when your filter bags resemble something like Swiss cheese – or half your bags fall off of the tube sheet!
The reality is that a differential pressure gauge is used to monitor just that – the difference in the pressure between the clean air plenum and the dirty side where the filters reside. This is a useful tool to determine proper cleaning procedures and to make sure you are not over cleaning and therefore damaging your filters and shortening their life. Many baghouse control systems utilize a DP gauge to turn on a cleaning cycle based on the pressure reading – and to shut off the cleaning when the differential returns to the desired level (i.e. keeping the DP reading between 4” – 8” of w.c.).
DP - an indicative measure
Regulatory agencies have often times required that baghouse operators use the differential pressure range as part of their compliance for proper operation and baghouse monitoring. The reason is simple – if you keep your DP in the recommended ranges – it means you are exhibiting proper maintenance and cleaning procedures – which can imply that you are at least paying attention to the operation of your dust collection systems. And while you may be properly operating your baghouse – you still won’t know when the filters start to fail.
Triboelectric - a predictive measure
If you want to know when your filter media is beginning to wear or small leaks are occurring – you need a device that detects the onset of still invisible particles – a broken bag detector or dust monitor – is the preferred instrument for this job. In many industries, environmental regulations require a Bag Leak Detection System (BLDS) on their dust collectors – but for those collectors that only require differential pressure monitoring or even just visual inspections – a broken bag detector can provide the early warning and assurance that your collectors are not causing an issue for your neighbors – or your parking lot!
Broken Bag Detectors and Monitors come equipped with several types of output – from simple on/off relay contacts to indicate an alarm, to continuous 4-20 mA outputs that can be taken to chart recorders or PLC systems, all the way to complete baghouse monitoring systems that can bring in signals from all of your baghouses and collectors and provide a centralized monitoring system – you have options to fit your requirement.
If you would like to learn more about our products and their capabilities, you may be interested in our eBook “Guide to Intelligent Monitoring” and how new systems are comprised of integrated instruments providing a wide range of parametric monitoring. For more information, click below.