Proper Baseline set up for Bag Leak Detection Systems (BLDS)

Posted by Nicholas Connell on Jul 14, 2015 2:00:00 PM

Is your triboelectric Bag Leak Detection System properly using a baseline to maximize your baghouse monitoring capabilities?

 

 What is my baseline? 


 
When setting up and observing your bag leak detection system, one of the most important monitoring trends to pay attention to is the baseline signal. This refers to the signal that is produced by normal process operation when not cleaning the filters. All filters allow small amounts of dust to escape during normal operations. It is this small amount of escaped dust that allows our particulate monitors to provide a baseline triboelectric signal. Properly monitoring the baseline allows for a full range of predictive and reactive alarms to be set, as well as telling you the day to day health of your baghouse.

 

Baselines vary depending on the particulate monitored, process conditions and type of filters used to prevent dust emissions. Often, no two baselines are alike as each monitored process will have individual characteristics that are unique to their application. For that reason, it is important to establish the proper baseline for each dust collector that is being monitored. The baseline is always present, which makes it one of the most important tools for baghouse monitoring.

 

How do I set a proper range?

 

To set up your bag leak detection system, you must establish the proper range for your application so that it properly displays and monitors your baseline. When a new particulate monitor is installed, or when verifying that your current settings are still accurate, a baseline setup procedure should be performed. This is done by evaluating the signal over a period of time that allows the system to capture the entire range of process activity that is considered normal operation. This should include complete baghouse cleaning cycles, different process levels or batches, or any routine process change that will influence the emissions being handled by the dust collection system.

 

(Care should be taken that the baghouse or filter medium is in good condition when performing this baseline procedure, as a baghouse with leaks will make it seem that the baseline is deceptively high—on many occasions we have received technical service calls allegedly about faulty signals from an Auburn Systems’ Bag Leak Detection System - only to troubleshoot and realize the problem was related to a broken or poorly installed bag!)

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At the end of this observation period it should be clear that there is a level of signal from the baghouse or filter medium being generated under normal conditions, and that is returned to after cleaning cycles. This is your baseline. You will use this value to set your overall monitoring range. Setting a proper range for your application is important, as this will allow you to properly observe both your baseline and cleaning cycle signals, and set different alarm level thresholds. Many users try to get the baseline too close to “0”, but that can decrease your ability to see what is happening within the system. A general rule of thumb is that your baseline should be 5 – 10% of your overall range. It is important that the system be able to see the fluctuations in the normal baseline as well as capturing the cleaning signal spikes for proper monitoring and trending.

 

The baseline is the foundation of your bag leak detection system since it is always present and indicating how your filters are performing. Establishing the baseline, determining the best range, trending the data, and setting a comprehensive alarm scheme are all important steps in finalizing your dust collector monitoring plan. ….Upcoming blogs specific to leak location, alarm schemes and how to best utilize historical data will be coming soon! In the meantime, check out some more helpful tips in “Our guide to intelligent dust monitoring’….

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Topics: Bag Leak Detection