Horizon Systems Addresses System Air Flow Issues Caused by Filters

January 2016 - Part I Pneumatic Conveying Troubleshooting Series

Horizon Systems Addresses System Air Flow Issues Caused by Filters

Is your system not providing the results you expect, but you’re not sure why or what to do? Most difficulties in pneumatic conveying involve some type of blockage causing a high pressure event or insufficient capacity due to product build up or system wear. Sometimes a combination of minor issues will add up over time affecting your overall system performance, as well as, stress individual parts and components.

When evaluating current system performance, it is important to have baseline records of expected convey pressures – empty and conveying, as well as, flow rates and temperatures that your system typically operates at for proper diagnosis. These records should be product and convey route specific and include feed rates for each. Charting your convey statistics over time is an excellent way to monitor your system performance. Comparing ideal conveying information to current state is where Field Service Technicians start their evaluation.

In Part I of our Pneumatic Conveying Troubleshooting Series, we will describe some of the most common air flow issues caused by inefficient filters and filter media that our Field Service Technicians see while on site and how they remedy these situations. Here are a few things to look for when it comes to maintaining your filter media.

Intake filters are any filters that are directly involved with drawing air into the system. These filters allow the system to “breathe” properly and must be kept in reasonable condition. You should avoid intake filters near dusty environments, as dust will affect functionality and life of the filter. Considering intake filters are often located outside the building and exposed to the elements, a weather hood may have been installed. Inspecting weather hoods for blockage should be a part of the system inspection. Drawing outside moisture into your system can cause all sorts of problems including a short filter life. Installing a weather hood can be an effective way of extending the life of the filter by protecting the filter from moisture and preventing moisture from entering the system.

Inline filters deal with protecting your blower package pump from ingestingproduct. Inline filters only get dirty if there is product passed through the baghouse filtration system; therefore, the issue becomes the destination baghouse and needs to be addressed.

Bag Houses and Filter Receivers collect nuisance dust and product to control exhaust contamination. When inline filters become clogged, the most likely issue is that the filter media in the bag house has a hole in it. Other possibilities are incorrectly installed bags or cartridges, or wrong filter material. Performing preventative maintenance on air filtration components requires knowledge of the typical differential pressure across the filters. New filters should run around 1 to 3” of water column. If the differential pressure consistently ranges over 7” of water column, then it is time to consider changing your filters. Having a routinely scheduled filter change is a great way to keep filters in good condition. The lifespan of filters is dependent on the ingredients and products processed, as well as, overall production hours.

Clogged air filters can negatively affect the efficiency of the blower and cause overheated and increased oil usage in addition to the effect on conveying. Air filters should be checked and replaced as part of an overall preventative maintenance program.

Bag Houses and Filter Receivers often have a compressed air cleaning sequence. An increase in differential pressure may be caused by a manifold pulse valve not firing. The manifold pulse valve sends a burst of compressed air down the length of the filter in order to clean it. It is not uncommon to have a pulse valve go out from time to time. A manifold pulse valve replacement kit provides a simple fix to keep downtime to a minimum.

Additionally, don’t forget to check the air header tank on the baghouse unit, as it should be held at pressures up to 120 PSI. Lower pressures could be used—most commonly pressures are between 75 and 100 psi. The air header should be supplied with a water separating air regulator to prevent moisture from coating the filter media which can be very detrimental.

Vent Socks and other component exhaust filters must also be accounted for when troubleshooting. These filters are positioned in many places throughout the facility and most often require visual inspection to make sure they are exhausting air and not dust. Inspection should be part of your preventative maintenance program.

For more addition information on filter troubleshooting, click here to read all of our tips. Look for our article in next month’s newsletter and read Part II about troubleshooting air leakage.

At Horizon Systems, we are committed to safety and stand behind our service. Our Field Service Technicians are experienced and knowledgeable as well as OSHA trained. If you’d like to talk with a technician or schedule an on-site audit or evaluation, please contact Jeff Koch, Field Service Manager, at (785) 856-8159 or jkoch@horizonsystemsinc.com.