A entry level triboelectric broken bag detection system - Courtesy of http://auburnsys.com/

By Dominick DalSanto
Baghouse.com

Quickly finding and replacing leaking filters is crucial for keeping a baghouse operating at peak efficiency. The longer you take to replace the leaking filter the more likely you will have to report the event to your air quality control regulatory agency (reportable event) and the more abatement costs you will incur.

How Broken Bag Detectors Work

How Triboelectric Dust Detection Systems Work

How triboelectric bag leak detection systems work – Courtesy of http://auburnsys.com/

Triboelectric broken bag detectors measure the amount of static electricity generated by dust particles in an airstream. Dust particles generate an electrical current when they encounter the insulated metal probe in the ductwork. A dust particle directly impacting the probe creates a DC signal while a particle passing near to the probe generates an AC signal. The latest generation of triboelectric detectors (such as the Auburn Systems’ TRIBO series) unify both signals and then output a measurement of particle concentration to a nearby control panel or transmit it to a PLC.

Using a Triboelectric Broken Bag Detector as Early Warning

Most leaking baghouse filters begin as small holes or rips that overtime become worse and worse. Catching a leak quickly is crucial. The longer a leak persists the worse it becomes, often quickly causing a plant to exceed its maximum PM 2.5 emissions limits set out in its air permit. Additionally, abatement requirements quickly increase as a leak continues over time.

Older optical emissions monitors (i.e. opacity meters) and optical bag leak detectors can only detect a filter leaking so badly damaged that the increase in emissions exceeds 10% opacity (often greater than the maximum permissible levels for many air permits).

Triboelectric systems are sensitive enough to detect even the smallest of increases in dust emissions such as when a bag first begins leaking. Operators can then examine the realtime trending emissions data to see whether it was a sudden spike indicates a damaged bag (such as from quickly worn hole) or slow rise indicating wearing filters.

 

Using Broken Bag Detector to Pinpoint Which Filters Are Leaking

An added advantage of triboelectric bag leak detectors is they can enable operators and maintenance technicians to pinpoint exactly which bags are leaking and need to be replaced.

Personnel should carefully monitoring emissions while cleaning system runs. When emissions spike during one cleaning cycle it means that leaking filters are present. Using this method, maintenance personnel can trace the leaking filters down to a specific baghouse, compartment and even row (pulse jet only) of bags. This saves time and money over traditional dye leak testing.

However, on older units, or when first beginning to troubleshoot a unit dye leak testing should still form part of your maintenance schedule. Dye leak testing can pinpoint multiple leaks at once, and in structural components as well as filters.

By quickly pinpointing leaking filters maintenance staff also reduce the amount of abatement required after the leak is fixed.

Below is the sample data from a test conducted to determine the differences in performance between a triboelectric leak detection system and a typical optical system (opacity meter). Notice the huge difference in response time and abatement required.

Leak Test ResultsTriboelectric Bag Leak DetectorOptical System
Estimated Time to:
Detect LeakLess than 1 Hour2-3 days
Locate Leaking Filter(s)Less than 1 Minute2-3 Man Hours (dye leak test)
Clean Up LeakLess than 1 Man-Hour8-10 Man Hours
Estimated Size of:
Hole Detected1/4”8”
Dust Accumulation2.6 cubic feet60 cubic feet
Dust Clean Up ToolShopvacShovels

Source: https://cdn2.hubspot.net/hubfs/354686/BrandBuilder%20Solutions/Case%20Studies/Aluminum_Case_Study.pdf

Reduce Baghouse System Downtime

When a baghouse goes down it often brings much down with it, from specific equipment to entire production lines to even entire plants due to emissions or health and safety issues. Preventing unscheduled baghouse shutdowns directly impacts the bottom line. In some facilities, losses from just one down day can add up to tens of thousands of dollars in lost production, fines and other costs. Therefore, investing in the maintenance and upkeep of these baghouse systems is well worth the initial capital costs.

Triboelectric dust monitoring system often prove one of the most cost-effect ways to improve dust collector maintenance and operation. With the ability to monitor emissions in realtime and trends over time, operators can better assess the condition and operation of their baghouses than those who rely solely on differential pressure.

For example, by carefully analyzing the triboelectric data trends maintenance planners can accurately predict when filters will no longer achieve their require collection efficiency and need a changeout. Further, they can begin preparations for the changeout in advance, sourcing filters and cages, obtaining contract labor for the changeout and scheduling the changeout for the next most convenient time (e.g. yearly maintenance shutdown). Compare this with the added costs and stress involved when a changeout is done at the last minute!

Additionally, as mentioned above, triboelectric bag leak detectors also prevent downtime by quickly alerting plant personnel to any leaks as soon as they begin to form. By catching leaks before they become serious plants can avoid stoppages for abatement, repair and any possible fines or sanctions from air quality regulators.

Recap of the Key Points

  • Triboelectric bag leak detectors directly impact the bottom line of your baghouse by improving maintenance efficiency, reducing downtime
  • Increased detection range means finding leaks quicker, before they become reportable events
  • See when filters first begin to fail allows predictive maintenance planning to reduce inconvenient shutdowns
  • Find leaking filter bags quicker, pinpoint down to specific unit, compartment and row without a dye leak test
  • Comply with MACT standards that require triboelectric broken bag detectors over opacity meters

Interested in a Triboelectric Broken Bag Detection System?

If you would like to know more about our line of triboelectric broken bag detectors  and how they can benefit your facility contact us today for a free consultation and quote!

Baghouse maintenance from Baghouse.com personnel
PTFE membrane on a baghouse filter under a microscope

Yes, there is a difference between the two. One is used to increase collection efficiency and one is used primarily for protecting the filter bags from chemical attack.

What Are PTFE Membrane Filter Bags?

PTFE membrane is semi-porous layer of PTFE bonded to the surface of a filter. This membrane acts at a permanent dustcake, capturing incoming dust particles (i.e. particulate matter or PM 2.5) on the surface of the filter (surface filtration) as opposed to normal filters that require a thick layer of dust buildup (dustcake) to actually reach peak efficiency. This means that PTFE membrane bags can operate at peak collection efficiency from the moment they are installed, and do not need to be precoated. Overtime, the membrane also works against the dust penetrating deep into the depth of the filter fabric, which is the cause of filter blinding. For this reason, PTFE membrane bags often last considerably longer than standard filter bags and have a more consistent differential pressure over time.

PTFE membrane on a baghouse filter under a microscope

PTFE membrane is a thin layer of PTFE laminated to the surface of a filter bag. It captures dust on the surface of the filter and easily releases the dust when pulsed.

PTFE Baghouse filters with PTFE membrane have the highest collection efficiency of all filters in production today. Bags using membrane technology can collect particulate matter down to 2.5 microns in size at over 99.99% efficiency. (In laboratory testing one OEM’s PTFE filters had 0.00% detectable emissions in the test rig). For this reason, in the applications with very tight emissions requirements, PTFE membrane filters are the standard.

Membrane bags are not recommended for a few limited applications, usually involving oils and hydrocarbons are these can close off the pores of the membrane and cause the filter to plug up.

What Are Filter Bags with PTFE Finish or Treatment?

In this use of PTFE, rather than creating a surface layer or membrane on top of the filter, the filter fabric is coated in a bath or spray of liquid polytetrafluoroethylene (PTFE) resin. This is done to protect the filter. The treatment improves the flex life, heat and chemical resistance and dust release from the fabric. This increases the service life and efficiency of the filters. PTFE finish is commonly used in applications with corrosive chemical compounds, sticky dusts, or high moisture contents.

Would you like to learn how PTFE membrane filter bags can improve your dust collector operation and save you money? Contact us today to find out more!

A Baghouse filter with PTFE (Teflon) Membrane

PTFE membrane or PTFE finish can be applied to a baghouse filter made from any fabric, such as fiberglass, polyester, or aramid (Nomex). It can even be used with pleated filters or cartridges.

Bent and rusted dust collector filter cages

The answer is that it depends…In many applications it is possible to reuse the cages once or possibly more. But in many other applications it may not be wise to reuse the cages.

Damaged Baghouse Cages From Corrosion and Mishandling

The main two types of cage damage we see are physical damage (bending, breaking, warping, etc.) and corrosion. Cages frequently get bent or broken by maintenance personnel over time by handling during changeouts and maintenance work. Other times, cages are damaged when stacked on top of each other for storage.  Additionally, fires or temperature excursions can warp cages.

Rip in a baghouse filter caused by a broken support cageCorrosion can occur from chemical attacks (e.g. acid flashes,) or upset conditions within the system. In some applications, high moisture levels can promote corrosion of the metal cages very quickly. And sometimes cages are stored outside uncovered  and left exposed to the elements.

Reusing Damaged Cages Will Cause Your Baghouse Filters To Fail Sooner!

There are three ways damaged or corroded cages cause filters to fail:

A bent baghouse cage has worn holes in the filter.

Bent or warped cages can eventually wear holes through your bags and cause massive leaks.Using damaged or corroded cages along with new baghouse filters will damage your filters and lead them to fail. This means you will experience leaks or even total filter failure much quicker than normal. Such failures can have high costs in terms of maintenance, possible system shutdowns, lost production as well as the costs of buying replacement filters sooner than normal.

  • When pulsed bent cages can cause the filters to rub against each other or against the sides of the collector causing the bags to tear open
  • Bent, twisted, or broken cages will have many sharp edges that can cut holes in the fabric very quickly when pulsed
  • Rusted or corroded cages will eat through the bag fabric and very quickly cause holes to appear.

In applications with very corrosive environment
(acid/alkali compounds, high humidity, condensation, etc.) such as foundries, dryers, chemical processing, etc., it is essential to avoid reusing cages that are damaged or corroded.

Even in applications with milder environments, the frequent handling of cages during repeated changeouts will eventually result in damage to the cages. Using cages in good condition extends filter life and improves efficiency by preventing:

  • Tearing or cutting filter on sharp edges
  • Damage from abrasion from other bags or unit
  • Corrosion eating through the fabric on the bags (Consider investing in galvanized, epoxy-coated or stainless steel cages to improve resistance to corrosion
  • Ineffective cleaning by ensuring the bags are properly fitted to the cages (Bags need to fit correctly
    across entire cage in order to get the required snap back when pulsed with air…not possible with bent cages

Reusing Damaged Cages Can Cost You Dearly

Bent and rusted dust collector filter cages

Corroded (rusted) cages will lead to early bag failure. Avoid reusing cages if they are damaged or corroded in any way.

Even minor rips, holes, and tears in the bags can lead to exceeding emissions limits. In many plants, such a problem will cause an emissions spike, becoming a “reportable event”, with possible fines and sanctions from regulators as a consequence. Additionally, any baghouse malfunction has the potential for causing plant-wide problems, that may lead to shutdowns, production losses and other costs far in excess of replacing the cages.
You can avoid all these problems and more by not using damaged or corroded cages in your baghouse. Additionally, if you keep spare cages on site at your facility make sure to store them where they are protected from corrosion and avoid stacking to many rows on top of another to prevent bending.

Baghouse Filter Cage Styles

Do you have corroded or bent cages in your baghouse? Let us give you a quote today for new cages along with your next set of replacement filters and receive a discount on both! Contact us now for a free quote.

Large backdraft workstation vented to dust collector by ductwork

Dust collector OEMs constantly try to come in with bids lower than competitors. In an attempt to do so, some baghouse manufacturers offer undersized systems. This article discusses what customers can do to avoid accepting a bid for an inadequately-sized baghouse dust collection system.

By Dominick DalSanto
Dust Collection Expert & Sales Director
Baghouse.com

”I’m sorry, but the other supplier came in lower than you. We went with their proposal over yours.”

I think there are few things I hate hearing more than those words in my position in baghouse sales. I can respect a client who has found a better deal on a comparable system. But I am upset when I hear that my competition came in with a bid lower than mine by recommending a grossly undersized system. As a sales professional, this particularly exasperates me as I feel these OEMs abuse the level of trust placed in them by the customer by offering something they know will not work properly — and because I know how big a problem it is in our industry.

Many sales reps apparently believe in the viability of their plans, and, thus, offer them in good faith, but others have — and will — propose systems that are smaller than customers require knowing that it will not perform adequately. The end result is that vital baghouse systems do not operate adequately, and customers, workers, and the community end up paying the price in the form of higher operating costs, safety hazards, and more pollutants.

The situation can present a major problem for customers as most of them rely on the experience and expertise of baghouse manufacturers or environmental technology experts to recommend a properly sized system. Lacking knowledge on dust collection engineering and industry best practice, customers must rely on others without being able to independently verify their figures.

The question this arises, how can customers prevent this from happening?

Baghouse Case Study at Silver Mine Lab

View of entire testing area equipped with a dust collection system

View of entire testing area including the various hoods and backdraft table connected to a dust collection system.

A few years ago, a silver mining operation contacted us and requested a technical inspection of one of the mine’s baghouse dust collection systems. The task was to examine a small 5,000 cfm system used for venting an onsite testing lab. In the lab, plant personnel conducted daily tests of ore samples taken from various locations in the mine to ascertain which areas had the highest concentrations of silver ore. The process for conducting these tests involved the use of several extremely harmful substances, chiefly lead and cyanide.The main concern was that during some recent evaluations for safety purposes, lead dust had been found on windowsills and in nearby rooms. Additionally, the amount of lead dust found on the clothing of workers in these areas — specifically lab technicians — was found to be several times higher than allowable under MSA standards, leading to one worker requesting a transfer to a different department. In addition, the system itself appeared to function at a very low level of efficiency and “did not seem to run properly,” according to staff.

Problem — An Undersized Baghouse System

Large backdraft workstation vented to dust collector by ductwork

Backdraft workstation – Draft (i.e. suction) on the table was so weak it could hardly contain any dust generated on the table

After conducting an inspection and reviewing several elements of the system, I immediately realized it was grossly undersized. It was “designed” to ventilate the testing lab using a series of venting hoods and vented workstations. There were five pickup points in the system that were connected directly to the baghouse, which was located just outside the exterior wall. The first drop point was a large backdraft workstation (Picture  #2), 72 in. x 36 in., for mixing the lead and other compounds together with the ore samples. There were three small furnaces — used to heat samples — with venting hoods of 32 in. x 39 in. above them. And there was one tall, ducted workstation, 32 in. x 39 in., used as a back-up for the other mixing station. Venting for everything went straight up through the ceiling to the main trunk (Picture #3), which then ran directly out through the exterior wall and into the baghouse. The main trunk was 12 in. in diameter, tapering to 10 in. then 8 in. then 6 in. The main workstation was connected using a 10 in. duct, and all others used a 5-in. duct (Picture #4) to connect the hoods to the main trunk.

Dust collection system ductwork above the ceiling of the testing room

The ductwork above the ceiling of the testing room. The size of the individual branches and the way they connect to each other was not designed according to industry best practice

According to the supplier-provided specifications, the baghouse had (49) 5.5 in. x 10 in. bags, and the system fan was rated for 5,043 cfm at approximately 10 in. w.g. of pressure. In this arrangement, the system should have resulted in an air-to-cloth ratio of approximately 7.15:1.

After manually taking airflow readings, I found that the system cfm actually was 3,969. Additionally, when we physically removed a sample bag and measured it, we found it to be 5 in. in diameter, not 5.5 in. as the spec sheet listed. After crunching the numbers, we determined that the air velocity was, at times, below 79 ft./m. This was less than one-50th of the minimum recommend air velocity for this application.

Venting hood connected to a dust collection system

One of the hoods over a test furnace. Notice the lack of curtains and small diameter duct going up out of the hood.

Poor ductwork design, a grossly undersized baghouse, and an equally underpowered fan combined to make this system almost worthless to the facility. (they neglected to size the fan based on the relative elevation and in doing reduced the output of the already undersized fan by another 30%) The effective pull from the system was so weak that one could place a hand directly under the intake on any of the stations and feel almost no noticeable suction — even when the system was running at full power. It was so weak it could hardly lift a piece of paper out of my hand! Obviously, this led to the excessive contamination of the workers and surrounding area.

Why So Small?

The system was designed by in-house personnel, who had no air-handling engineering experience, and a testing lab consulting company. The consultant procured the system from a sales rep organization, which, in turn, procured it from another independent sales rep that worked with the manufacturer. The final cost of the system was more than $75,000 for the baghouse, fan, ductwork, and hoods — much of that being mark-up for all the parties involved. The system was undersized from the start, so while cheaper for the customer, it ended up virtually useless for that customer.

Using even rough calculations, with a minimum conveying velocity of 250 ft./m in the hoods — and that really should have been even higher — the system would have required at least 12,000 cfm to function at an adequate level. Heavy dusts such as lead require high conveying velocities between 4,000 ft/min or more to prevent product drop out. This would mean a much larger system fan, (adjusted to the 4,400-foot geographic elevation of the plant), a baghouse with either triple the amount of bag filters or the use of pleated filter elements to increase filter area, and a completely redesigned ductwork system with a larger trunk and branches, along with better hood design and a damper system to further increase collection efficiency.

Solution — How to Avoid Being Sold an Undersized System

Some may feel that this case study serves only as a horror story to scare potential buyers on the pitfalls of trusting unscrupulous salespeople. I agree that part of the reason for telling this story is to advise you that implicitly trusting any vendor trying to sell you something as large and expensive as a dust collection system is not wise. The main moral of the story, however, is to help you make sure you get the best dust collection system for your needs. In the previously outlined case study, the following steps may have helped prevent this disaster:

1) The first step is to do your homework before you call for quotes. While becoming an expert on every piece of industrial equipment before contacting vendors isn’t feasible, gaining as much knowledge as possible goes a long way to ensuring you get what you need. Knowledge provides you with leverage during the sales process. Since, in this case, company personnel went in completely ignorant of how a dust collection system operates, they were at the mercy of whatever their vendor was going to tell them. This meant they had no idea of air-to-cloth ratios, air conveying velocities, ductwork design, etc.Additionally, where possible, deal directly with a baghouse dust collector manufacture (such as Baghouse.com) as opposed to sales rep organizations, that often have little to no practice experience engineering dust collection solutions.

2) Second, verify vendor calculations. While at times you may be able to determine exactly what size a system you need on your own, you may require assistance. This is especially true with regard to new installations and new processes. There is nothing wrong with asking vendors to assist you, but make sure to review their numbers afterward. This may require a bit of research or even hiring an outside consultant to verify the engineering. In the case study, had plant personnel taken the time to review system specifications proposed by the vendor, people would have found that the figures were far off from accepted industry standards. (See the American Council of Governmental Industrial Hygienists (ACGIH) Manual for standards on minimum air-conveying speeds and system design standards.) This would have exposed that the system was grossly undersized and allowed staff either to correct the problem or to seek a different vendor.

3) Third, seek alternative proposals. Had the company solicited alternative bids, personnel likely would have noticed the obvious discrepancies between them. Additional proposals likely would have shown a large difference in price, owing to the vendor’s undersizing of the system. Other vendors (likely) would have submitted more realistic proposals. Instead of believing that any one supplier somehow may have managed to undercut the competition by such a large margin — while offering an adequate product — the wise course would be to investigate why one bid would come in so much lower than the others and correct any mistakes that may have been made.

Conclusion

Yes, this story is meant to raise concerns over the buying process, but that is a good thing for potential buyers. If they keep in mind the points outlined here, they can avoid the pitfalls of an installing an undersized dust collection system and avoid the complications that can come with it.

Magnehelic gauge for reading differential pressure in a baghouse

Slag processing facility recently agreed to pay over $325,000 in fines for a violation of their air permit. What major infraction lead to such an immense fine? A broken differential pressure gauge on their baghouse! 

By Dominick DalSanto
Dust Collection Expert
Baghouse.com

Portage, Indiana – On September 18th, 2014 a manufacturing plant agreed to pay $325,000 in fines over a broken dust collector differential pressure gauge and falsified reports.

Calumite Company LLC manufactures an additive for the glass industry made from recycled slag from nearby steel mills. As part of its air permit with the state of Indiana, the company is require to operate dust collection systems throughout the plant and to record and report their operation efficiency to state regulators.

Over a period of at least 16 months this particular unit did not have a working differential pressure gauge (also called a magnehelic gauge). Rather than replace the broken gauge, workers regularly estimated DP readings for their reports and then submitted them to state and federal regulators as required. The dust collector in question controlled emissions from the loading and unloading of the company’s product onto railcars and truck trailers. During the course of the investigation, several workers admitted to falsifying reports, and supervisors even admitted to knowing about the broken gauge, but signed-off on the readings and submitted the reports anyway.

Magnehelic gauge for baghouse dust collection system

A broken baghouse differential pressure gauge resulted in massive fines for one facility

What is Differential Pressure on a Baghouse?

State and federal regulators often use differential pressure readings to determine how efficiently a dust collector operates and thus use it as a standard for controlling emissions. Differential pressure is the difference in pressure between the clean and dirty air sides of a dust collector. As dirty air passes through the filters in a dust collector it encounters resistance from the fabric and any buildup dirty on the filters. When the filters are clean there is less resistance and thus a lower drop in pressure between the two compartments inside the dust collector. For this reason, differential pressure readings tell operators the current condition of the filters and the unit in general. If the DP is high, it can signify high dust loading, filter blinding (i.e. clogged filters) which in turn lead to high emissions. A abnormally low reading can also mean that the filters have holes in them or have come lose…also resulting in high emissions.

Lessons Learned? – Do Not Neglect The Dust Collectors

The company was fined for operating one of its dust collectors without taking accurate differential pressure readings. While most dust collection related penalties and fines are related to failure to replace blinded or torn dust collector filters (often due exceeded service life, lower efficiency media, or pushing too much airflow through the filters) this fine comes solely from a failure to accurately monitor the dust collector operation and to record and report it accurately.

The take away here is to never neglect dust collection system maintenance, operation, and especially as this case highlights, reporting. While keeping up with the many regulations, regulations, standards, and requirements imposed on facility managers for dust collection systems might pose a challenge, forgoing the needed maintenance to change something seemingly small and unimportant (in this case a DP gauge) will eventually cost far more in fines, lost productivity, system downtime, and repair costs than maintaining the system properly ever will.

Link to official case record: https://www.justice.gov/opa/pr/indiana-manufacturer-pleads-guilty-clean-air-act-false-statement-violations

 

Baghouse.com now offers free dust collector inspections to new customers in the Los Angeles and San Diego areas.

By Dominick DalSanto
Baghouse Technology Expert and Sales Director
Baghouse.com

Baghouse.com News | Beginning June 1st, new customers in the Los Angeles and San Diego areas can request free site visits from Baghouse.com. Visits from a dust collector engineer provide far greater value than the usual method whereby companies merely send manufacture’s representative to pitch products.

Upon request, a dust collector engineer will arrange to visit the facility and conduct a condensed version of a standard dust collection system audit. They will visually inspect and review the plant’s dust collectors (if exceptionally large facility , then only primary units), review operating conditions, maintenance procedures, and discuss overall system performance and issues with operators and maintenance personnel. After reviewing the data, the dust collector engineer will present a set of recommendations to improve system efficiency, capacity, and service life of filters, while also reducing maintenance, operating costs (e.g. electricity, compressed air usage, replaceable parts, etc.) and system downtime. If any specific issues are identified during the inspection, or presented by plant personnel, these also will be addressed in the report.

Benefits of a Baghouse.com Dust Collector Report

Free dust collector inspection and report from Baghouse.com

Many of our current customers have benefited from our recommendations. By putting into practice our recommendations they increased efficiency, capacity without large capital investments, reduced down-time, operating costs, and lowered emissions and improved safety (due to air quality) within their facilities. Here are just some of the items we often identify during a free site visit:

  • Troubleshoot existing issues and work with staff on how to resolve them
  • Filter selection: recommend alternative fabrics, finishes (e.g. PTFE membrane), filter types (e.g. pleated filters
  • Baghouse condition and unit selection:
    • Recommend repairs (structural, pulse valves, gaskets, etc.)
    • Identify shaker and reverse air units with potential for retrofitting into newer pulse jet style
    • Condense several inefficient small units into one larger system,  etc.
  • Examine current operating methods and make recommendations on how to improve efficiency, reduce operating costs and system downtime (e.g. startup and shut down procedures, fan operating parameters, cleaning system settings, etc.)
  • Examine current maintenance procedures and make recommendations for improvement. Includes daily, weekly, monthly, yearly procedures, inspection checklist, handling of replacement bags, diagnosing need for bag replacement, proper bag replacement techniques, etc.
  • Replacing out of date equipment and methods with latest technology, such as pleated filters, clean-on-demand cleaning, PTFE membrane filters, etc.
  • Recommendations for new OSHA standards for combustible dust, such as explosion protection and fire suppression systems.

Request Your Free Dust Collector Report Today!

To request a free visit in the Los Angeles and San Diego areas, simply contact Baghouse.com by phone at 800 351 6200 or send us an email and ask for information about our free Las Vegas dust collector inspections and reports. For more information please see the following pages:

 

| Dominick DalSanto is an author & dust collection technologies expert, specializing in dust collection systems. With nearly a decade of hands-on working experience in the industry, Dominick’s knowledge of the industry goes beyond a mere classroom education. He is currently serving as sales director at Baghouse.com. His articles have been published not only on Baghouse.com , but also on other industry related blogs and sites. In his spare time, Dominick writes about travel and life abroad for various travel sites and blogs.

Best practice for installing a baghouse magnehelic differential pressure gauge

This simple baghouse accessory can mean the difference between a properly functioning baghouse and an operational disaster! Use this guide to ensure proper installation and maintenance of your differential pressure device.

By Dominick DalSanto
Baghouse Technology Expert and Sales Director
Baghouse.com

One of the most common issues we identify during our dust collection system audits/inspections  is poorly installed and maintained differential pressure system components (e.g. magnehelic/photohelic gauges, DP air lines, DP taps, etc.). As we have covered in previous articles in this series, having accurate differential pressure readings is essential to proper dust collector operation.

Baghouse differential pressure air lines

Avoid the example here. Avoid splitters and crooked lines.

I was recently asked by one of our readers if we could write an article on how to install the differential pressure reading system components for a baghouse. The process, like many baghouse-related items, is not complicated. However, there are some industry best practices that make maintenance easier and reduce likelihood of problems in the future.

This guide can be used regardless of what kind of differential pressure reading system you are going to use. The process is the same for magnehelic and photohelic gauges, as well as timer boards and control boards with on-board pressure sensors.

Installing a Baghouse Differential Pressure System

  1. Determine what kind of differential pressure controls you will use
    • Magnehelic gauges are simple and provide reliable data. However, they alone cannot be used to control the cleaning system on a baghouse.
    • Timer boards are useful for processes that are consistent in dust loading and operating schedules, but must be manually set by operators.
    • Clean on demand systems are the best choice for controlling a dust collector. Often, these systems are all in one controllers, or they are a mix of a control board with an external photohelic or magnehelic gauge for pressure readings
    • Air lines running between the controls and the baghouse can be plastic, carbon fiber, or even metal (copper or aluminum). Plastic or carbon fiber lines are easier to run, but metallic lines are much more durable and will require far less maintenance in the long run.
    • Consider installing secondary magnehelic gauges for redundancy and easy reading by maintenance personnel.
  2. Decide on the location of your control(s)
    • Locate your controls where they can be easily accessed by maintenance personnel. With smaller units often the most convenient location for controls and gauges will be on the ground level. Good locations include on supports or nearby walls. On larger units, controls are best located near the doors or along access platforms. Common locations include next to the door, above the pulse valves and compressed air header, or on a nearby wall or column.
  3. Decide on the location of your air taps and plan your air line runs
    • Air taps are best placed near the corners of the clean and dirty plenums. This minimizes the amount of dust that can enter back into the air lines and possibly foul the DP sensors. Try to keep them about at least 6″ from the walls and in the corners where practical. Keep both taps near each other for easy access when performing maintenance.
    • Decide on the best path for your air lines. Avoid runs over 100′ as this may affect the accuracy of the readings.

Common Issues with Dust Collector Differential Pressure Gauges

Problem: I hooked up the DP lines, but my DP sensor is giving me a negative reading.

Solution: You likely have the lines mixed up. Try switching the lines on the inputs.

Problem: I have the lines set up correctly, but I am getting very low readings (usually under 1″).

Solution: Before installing the both lines, you need to zero out the gauge. Attach one side and then with the other one off zero out the DP sensor. Now when you attach the second line it should give an accurate reading

Problem: My controller is setup, but the solenoids are not firing.

Solution: Check your wiring to make sure you have everything correct. Often, the common line from the solenoid to the control is mixed up with one of the control wires. Double check everything and follow the wiring diagrams from your manufacture exactly. 

Special Thanks

A special thanks goes out to one of our readers, Tim Skiba, for suggesting this subject for an article.  If you have any topics that you would like to see discussed on Baghouse.com, please share them with us in your comments below. Thank you so much for reading.

 

| Dominick DalSanto is an author & dust collection technologies expert, specializing in dust collection systems. With nearly a decade of hands-on working experience in the industry, Dominick’s knowledge of the industry goes beyond a mere classroom education. He is currently serving as sales director at Baghouse.com. His articles have been published not only on Baghouse.com , but also on other industry related blogs and sites. In his spare time, Dominick writes about travel and life abroad for various travel sites and blogs.

Baghouse.com now offers free site visits to new customers in the Las Vegas area to all new customers. 

By Dominick DalSanto
Baghouse Technology Expert and Sales Director
Baghouse.com

Baghouse.com News | As of May 1st, Baghouse.com now offers free on-site visits to all new customers in the Las Vegas, Nevada area. These visits will provide potential customers with a more personalized relationship with the company. Upon request, a baghouse engineer will arrange to visit a facility on-site to introduce the company’s products and services. Where possible, the baghouse expert will tour the facility and examine its dust collection systems. When finished, the Baghouse.com representative will review their findings with plant personnel and issue a brief written summery within one week. This will include an overview of the facility’s dust collection systems and general recommendations for areas where improvement can be made.

Benefits of a Baghouse.com Dust Collector Report

Free dust collector inspection and report from Baghouse.com

Free dust collector inspection and report from Baghouse.com

Many of our current customers have benefited from our recommendations. By putting into practice our recommendations they increased efficiency, capacity without large capital investments, reduced down-time, operating costs, and lowered emissions and improved safety (due to air quality) within their facilities.

Here are just some of the items we often identify during a free site visit:

  • Troubleshoot existing issues and work with staff on how to resolve them
  • Filter selection: recommend alternative fabrics, finishes (e.g. PTFE membrane), filter types (e.g. pleated filters
  • Baghouse condition and unit selection:
    • Recommend repairs (structural, pulse valves, gaskets, etc.)
    • Identify shaker and reverse air units with potential for retrofitting into newer pulse jet style
    • Condense several inefficient small units into one larger system,  etc.
  • Examine current operating methods and make recommendations on how to improve efficiency, reduce operating costs and system downtime (e.g. startup and shut down procedures, fan operating parameters, cleaning system settings, etc.)
  • Examine current maintenance procedures and make recommendations for improvement. Includes daily, weekly, monthly, yearly procedures, inspection checklist, handling of replacement bags, diagnosing need for bag replacement, proper bag replacement techniques, etc.
  • Replacing out of date equipment and methods with latest technology, such as pleated filters, clean-on-demand cleaning, PTFE membrane filters, etc.
  • Recommendations for new OSHA standards for combustible dust, such as explosion protection and fire suppression systems.

Request Your Free Dust Collector Report Today!

To request a free visit in the Las Vegas area, simply contact Baghouse.com by phone at 800 351 6200 or send us an email and ask for information about our free Las Vegas dust collector inspections and reports.

For more information please see the following pages:

 

| Dominick DalSanto is an author & dust collection technologies expert, specializing in dust collection systems. With nearly a decade of hands-on working experience in the industry, Dominick’s knowledge of the industry goes beyond a mere classroom education. He is currently serving as sales director at Baghouse.com. His articles have been published not only on Baghouse.com , but also on other industry related blogs and sites. In his spare time, Dominick writes about travel and life abroad for various travel sites and blogs.

Baghouse differential pressure air lines

For baghouses to run efficiently, trustworthy differential pressure readings are required. How can you tell if your DP readings are accurate? What can you do if you suspect you are receiving false readings? This second article in our series on baghouse differential pressure will answer that question. 

By Dominick DalSanto
Baghouse Technology Expert and Sales Director
Baghouse.com

Why Worry About False Differential Pressure Readings?

As we mentioned in our previous article in this series, having accurate differential pressure readings is essential to operating your baghouse correctly, and efficiently. Operators base almost all of their operational decisions on baghouse DP. If they are given incorrect readings it could result in damage to the system, increase emissions, or even fire and combustible dust hazards.

For example, assume that a unit is giving readings that are lower than they actually are, 3″ w.g. when it really is running at 8″. Because the operator sees such a low reading, he could now make several incorrect operating choices that could have very severe consequences. He may take this low DP reading to mean that his filters are in good condition and do not need to be replaced. With blinded bags, he could begin seeing decreased system performance. Or perhaps his bags could begin producing higher emissions levels thus causing the plant to exceed its air permits, potentially leading to heavy fines and sanctions.

While we cannot detail every possible problem that could arise from this, the point is clear. So what can and maintenance personnel do if they they are receiving incorrect DP readings?

How To Troubleshoot Differential Pressure

Maintenance personnel should examine the DP instruments and determine if there is any obvious problem. Lose connections, backwards connections, and obviously broken gauges are common enough that they should be expected.  Other times, maintenance personnel will need to troubleshoot the instruments to diagnose and remedy less conspicuous issues.

Maintenance personnel will need to determine whether the individual pressure gauges are faulty, or simply have blocked lines coming into them. We recommend the following troubleshooting procedure:

  1. Disconnect all gauges, controller boards, etc., from air lines coming from the collector.
  2. Using compressed air, clean all air lines thoroughly, making sure to blow back into collector.
  3. Using a handheld DP gauge (a normal manometer with flex tube connectors will suffice), hook up the air lines from the collector to obtain the operating DP.
  4. Reconnect the newly-cleaned air lines to the controller board and/or pressure gauge.
    1. If the controller board/pressure gauge reads the same as the handheld gauge did after cleaning the lines, then the controller board pressure sensor and/or pressure gauge is working properly
    2. If the controller board/pressure gauge reads the differently than the handheld gauge did after cleaning the lines, then the controller board pressure sensor and/or pressure gauge is not working
      1. (For the baghouse-mounted DP gauge) Replace with new gauge.
      2. (For controller board) Contact manufacturer about possibility of replacing only the board’s pressure sensor.
        1. If not possible, replace entire board with new controller board.
  5. Remove all unnecessary line splitters, additional lines, and long runs, ensuring all gauges are located as close as possible to the air taps (within 10’ – 15’)
Baghouse differential pressure air lines

Avoid the example here. Avoid splitters and crooked lines.

NOTE: When connecting the new gauge to the clean and dirty side lines, make sure to connect them to the correct ports on the gauge. They should be marked “HIGH” and “LOW”. Just remember, that if hooked up backwards, the needle will pull backwards, instead of giving a positive reading.

How To Prevent False DP Readings

It is important to remember that just because you fixed this problem once, it likely will come back again and again over the life of the baghouse. Inspecting and cleaning/repairing the DP gauges and air lines should be a regularly scheduled maintenance task for all baghouses.Industry best practices should be followed when installing the gauges and air taps to reduce the likelihood of fouling.

Notice in the picture to the right how the maze of lines coming in and out this DP gauge. Best practice is to have just one line from each side of the baghouse coming into the gauge. The lines should run in the most direct and shortest path possible. For this reason, avoid locating the gauges exceedingly far from the unit, such as in other rooms or other floors. Further, to avoid buildup in lines themselves, place the taps near the top corners in each side of the unit.

Baghouse Differential Pressure - Good air lines

A better example of how lines should be run.

Also, using copper line as opposed to plastic or rubber tubing is preferable and we facilitate easy cleaning and is far more durable.

Once You Have Accurate Readings

With your now trustworthy readings in hand you can now begin consider what these readings in conjunction with other available information is telling your about your baghouse.Our next article in this series will examine how to understand your baghouse DP readings and use it to make wise operating decisions.

 

 

| Dominick DalSanto is an Author & Environmental Technologies Expert, specializing in dust collection systems. With nearly a decade of hands-on working experience in the industry, Dominick’s knowledge of the industry goes beyond a mere classroom education. He is currently serving as Sales Director at Baghouse.com. His articles have been published not only on Baghouse.com , but also on other industry related blogs and sites. In his spare time, Dominick writes about travel and life abroad for various travel sites and blogs.