Business growth creates new challenges. This is the case for plant engineers and maintenance managers responsible for the efficient operation of the most common form of dust collection equipment — pulse-jet baghouses — used in foundries across the globe. Many baghouses were designed and built to accommodate a certain amount of air flow that was sufficient for past demands. As foundries have increased production, these flow requirements have amplified and the original design of the baghouses are no longer suitable. Their obsolescence is perpetuated by raised scrutiny on emissions and the focus on the business community’s responsiveness as good corporate neighbors and stewards to a sustainable environment.
In this blog, we will explore pleated filter element (PFE) technology and examine how two foundries successfully upgraded their pulse-jet dust collectors by installing PFEs, resulting in:
The Environmental Protection Agency (EPA) and Occupational Safety & Health Administration (OSHA) regulations have become increasingly more stringent, requiring foundries to upgrade their current operational ventilation systems to comply with regulatory standards. Foundries have evaluated their furnaces, shakeout, pouring and cooling lines, sand handling systems, finishing areas and many other parts of their operations reliant on pulse-jet dust collectors for proper ventilation. Their evaluations have found a multitude of problems, including:
As a result, foundries are looking for ways to upgrade their dust collection. The most economical and preferred option is to modify existing baghouses rather than installing completely new systems, which would require significant capital investment. PFEs provide an effective solution to this challenge.
Pleated filter elements, such as those manufactured by Parker Hannifin, are filters that use either a molded polyurethane or metal top and bottom that are used as direct replacement for standard felted filter bag and cage assemblies in pulse-jet baghouses, as well as in new equipment. Spun-bonded polyester fabric is the most common media used in PFEs because of its tight pore structure and rigid physical properties that allow it to hold a self-supported pleat —providing as much as 200 to 300% more filtration area at 99.992% efficiency than a filter bag in the same tubesheet hole.
A major Midwest foundry used a three-compartment, 882-bag shaker baghouse to ventilate four induction furnaces, a scrap preheater system, and a magnesium inoculation station. The foundry struggled with the following problems in its dust collection system:
As a solution, the company converted the original shaker system to an engineered pulse-jet style cleaning system using BHA® PFEs manufactured by Parker Hannifin's Industrial Gas Filtration and Generation Division. The baghouse was retrofitted with a new tubesheet and a walk-in clean air plenum, to allow for a top-load design filter element. The baghouse has been operating consistently since the retrofit.
Since the retrofit, the baghouse has been operating consistently and the following results have been reported:
A large foundry that manufactures castings for the automotive industry had a top-load design pulse-jet baghouse that contained 650 felted filter bags and cages. The unit ventilated several shot blast cabinets, grinders, and other finishing equipment. The system was originally designed at an air-to-cloth ratio of 6.1:1. The filter bags measured 5.25 in. in diameter by 12 ft. in length, for a total cloth area of 16.5 ft2 per filter bag. The challenges the foundry was experiencing with the current design were:
The foundry engineering team determined that installing Parker BHA PFEs in the dust collector was the most cost-effective solution.
Post installation results include:
Pulse-jet dust collectors used in most foundry applications can be successfully upgraded with the installation of pleated filter elements. The case studies show that when aggressively designed to air-to-cloth ratios and demands for increased airflow capacity cause poor dust collector performance, the installation of PFEs can dramatically lower differential pressures, improve filtering efficiencies, reduce emissions and lower overall plant maintenance requirements.
This blog was contributed by the Filtration technology team, Parker Industrial Gas Filtration and Generation Division.
13 Mar 2019
Gas turbine performance is affected by the environmental challenges of a specific power plant installation. In a recent project located in the Middle East, a filtration solution to protect the turbine needed to be designed to address each of the conditions faced, including varying amounts of:
The spectrum of potential hazards that could be faced at a turbine installation means one filter cannot meet all needs. Even the different forms of dust or moisture present need to be considered within the design of the filter house.
A brutal environment for gas turbines
In the Middle East, a mixture of sandstorms, heat, mist and moisture from random fog events, make for a brutal environment for a gas turbine. It is the combination of the moisture in thick fog combined with high dust concentrations that can be particularly challenging for a gas turbine filter system.
Without the correct design and implementation of a system, the installation is at risk of sudden pressure increases, gas turbine shutdowns, difficult and time-consuming maintenance and greatly shortened filter life. Indeed, as one operator was experiencing, it is not uncommon for pre-filters to require changing every two or three days and final filters to need replacement after just six or seven months, as opposed to a normal life expectancy of over two years. The increased labour and ongoing cost to keep operations running and reduced availability of the gas turbine were having a serious impact on the operation’s bottom line.
The gas turbine installation in question was at a power plant in a coastal, desert location in the Middle East. Seasonal fog events and extremely high levels of dust were causing havoc with the system. After careful review of the installation and specific environmental conditions, however, relatively simple changes led to a dramatic improvement in performance.
When to pulse – and when not to
One of the first areas to be considered was the pulse system settings. A pulse system removes dust build-up on the filter and tends to operate in one of two ways. In the first, it can be set to run continuously without regard for the differential pressure.
Alternatively, however, it can be configured to run when the differential pressure across the filter reaches a certain level. Once this level is seen, the pulse system turns on, cleans the filters and then turns off when a low differential pressure setpoint is met.
The site’s pulse system was set to run continuously. The issue this created, however, was that the fine dust in the area was leaving the filters in a dust cloud and simply becoming re-entrained on the filter. The system was changed to operate only when differential pressure reached a pre-set trigger level. The switching levels were established based on testing with the local environmental conditions and found to be optimized with the system turning on at 1.5” wg (water gauge) and off at 1.0” wg. This meant the filters were cleaned before pressure became an issue but not before a dust cake built up on them that enabled gravity to help the dust move down the filter house. Typical set points for pulse cleaning start around 3.0” wg and stop at 2.5 or 2.0” wg.
Handling the moisture from the fog
The next area to be considered were the coalescers, which were experiencing serious issues. Coalescers are used to remove moisture from the air flow prior to it reaching the filter. If there is a lot of moisture in the air flow when it reaches the filtration stages, small moisture droplets combine with the dust and sand to create blockages and sudden increases in differential pressure. The size of these droplets means they can also work their way into the matrix of the filter media and get stuck. Coalescers usually work to prevent this from happening by combining small moisture droplets to form bigger, heavier ones — many of which will then naturally fall out of the airflow.
The site in question had traditional coalescers installed, known as mat coalescers, which employ media similar to that used in dust filtration. The issue with these, however, was that the high volumes of dust were quickly clogging them and, with no path for the inlet air flow, they were being forced out of place. Once the air was able to completely bypass the coalescers, the moist air and dust were continuing to the filter and creating blockages. Placing the coalescing technology with a modern, fully washable, 100% synthetic mesh resolved this issue and, even after 12 months of operation, the coalescers remain firmly in place and doing the task for which they are installed.
Unlike the traditional mat equivalents, the new synthetic media coalescers had been specifically designed to allow the sand and dust to pass through. The new units work by using a two-stage coalescence configuration. The first stage is a moisture separator with coalescing efficiency down to 50 microns. The second stage, a clearcurrent TS1000 coalescer, has 99 percent coalescing efficiency for droplets down to 10 microns but which has limited dust removal capability. It is this deliberate limitation of dust removal capability which avoids blockages and significantly reduces the maintenance overheads where high levels of both dust and moisture are present. The dry dust is then easily handled by the filtration system, to prevent it from damaging the turbine.
Two simple changes equal huge improvements in performance
Following these two changes on site, pulse system settings and coalescer technology employed, the site has experienced no shutdowns because of problems with the filter system or sudden differential pressure increases. The self-cleaning filter life is exceeding the customer requirement of two years and maintenance intervals have been extended. This has reduced operating costs, limited manual labour interventions required, and increased production availability — significantly improving operating profits.
In regions where extreme conditions as found, such as in the Middle East, operators are advised to:
Success is not about paper specifications
Measurement of the success of a filtration solution cannot be measured by specification comparisons or laboratory testing, as these do not portray the real-world conditions of each installation. Instead, success criteria need to be based on critical factors such as the reduction in turbine downtime and outages for filter replacements.
The example given above shows that, with the correct experience and expertise, significant improvements to turbine performance can be gained with even relatively small solutions and adjustments. System design and settings need to be geared towards the real-world environment in which the solution is installed. Working with filtration experts, other turbine operators can benefit from evaluating total solution management of their inlet systems.
View the presentation given at Middle East Rotating Machinery Technology and Innovation Conference & Showcase (ROTIC) 2018
About Parker Gas Turbine Filtration
With more than 50 years of experience delivering innovative solutions for gas turbine inlet filtration and monitoring fleet-wide performance data, our industry and applications experts will select the appropriate filter for your site designed to meet your specific operating goals.
Parker Gas Turbine Filtration supplies a full range of inlet systems and filters engineered to meet your operating goals, including:
Through our Parker brands, altair® and clearcurrent®, we are the choice for advanced filtration for new units and replacement filters. Our inlet system designs include self-cleaning (pulse) and static inlet systems for all gas turbine OEMs. We supply a full range of filter types at all efficiency levels. The predictable and reliable performance of our air filters significantly reduces compressor contamination and the need for unplanned maintenance for gas turbines in power plant applications.
This article contributed by David Trisante and Dan Burch.
David Trisante is sales director at Parker Hannifin Gas Turbine Filtration division. Trisante earned his engineering degree in the prestigious Universitat Politecnica de Catalunya (Spain) and the Aalborg Univeritet i Esbjerg (Denmark). He holds more than 20 years’ experience in purification and air pollution control markets as well as in a variety of filtration equipment ranging from dust collectors, electrostatic precipitators or gas turbine air intake systems.
Dan Burch is pricing manager, Gas Turbine Filtration (GTF) Division, Parker Hannifin. He’s covered all aspects of the company’s filtration offerings, with a particular focus on developing marketing and pricing strategies for gas turbine inlet filtration products. He has 15 years of experience in marketing and journalism roles. Dan has a B.A. in journalism from Indiana University and an MBA in marketing from the University of Missouri-Kansas City (UMKC).
The case study and paper were presented as part of the Middle East Rotary Machinery Technology 2018 conference.Related content
24 Jan 2019
The consequences of failure during downstream processing are severe. Following the Affinity Chromotography stage, the value of the product increases significantly at every step. A failure at the final bulk filling stage, therefore, could lead to the waste of millions of dollars’ worth of drug product.
It’s vital, therefore, to safeguard the bulk filling process. But traditional methods of conducting bulk fill operations have several disadvantages including:
1. Manual handling
This introduces the possibility of human error to the bulk filling process. It is also labour intensive, meaning that process operators need to divert their resources into this task.
2. Operator training
When bulk filling is carried out manually, investment must be made in operator training. This can be costly, both financially and in terms of the time dedicated to it by personnel.
3. Supply chain complexity
By using a range of components from several different suppliers in the bulk filling process, there is more potential for variation – and more time must be spent on sourcing and ordering suitable components.
4. Laminar air flow (LAF) maintenance and validation
In traditional bulk fill operations, laminar air flow must be maintained and validated to protect the products from contamination. This requires time and resources.
5. Shipping issues
At the shipping stage, poor handling of bottles – and the use of unsuitable containers – can lead to damage to products before they even arrive at their destination.
6. Non-standard operations and process variability
Traditional methods of bulk filling introduce variability into the process. If bulk filling operations aren’t standardized, they can be subject to a number of factors which can impact the final product. Factors such as different flow rates applied by different operators come into play.
Automating and enclosing bulk fill operations can address the challenges detailed above and increase safety for operators. Parker Bioscience Filtration has developed the SciLog® SciPure FD system as an automated and integrated single-use system for final bulk filtration, filter integrity testing and dispensing into final bulk product containers.
Here are some of the benefits:
This reduces the risk of human error from manual handling and allows operators’ resources to be spent on other tasks.
Standardizing operations means that training can be simplified and variations in the process can be eliminated.
Enclosing the process allows operators to process highly potent molecules and protects both the operators and the process. And, as the flow path is completely enclosed, both filtration and dispensing can be performed in areas of lower classification, eliminating the requirement for vertical laminar flow cabinets.
The SciLog® SciPure FD system
The SciLog® SciPure FD system benefits from innovative component selection based around material science studies, improved filling accuracy (+/-1%), and greater flexibility in the scale of filling (from 50ml samples to 20L).
The system features include a barcode reader for manifold tracking, reverse flow and purge options to maximize product recovery and fully programmable alarms and interlocks to product and process.
A validated shipping solution
To reduce the risk of damage to the product when shipping, Parker Bioscience Filtration has designed a fully validated shipping solution to complement and extend the capabilities of the SciLog® SciPure FD System. Parker Bioscience Filtration has created a unique bottle design that offers manufacturers the confidence that bulk drug products will arrive at their final destinations without contamination.
Parker Bioscience Filtration drew on its extensive material science knowledge during the development of the bottle and material selection was based on an FMEA study. The bottle integrity has been validated down to -89˚C.
Parker Bioscience has also developed an anti-foaming device that eliminates foam and enables a higher filling speed.
The development of the SciLog® SciPure FD System is an example of the change in the vendor/end user relationship: by using a vendor such as Parker Bioscience Filtration, which can provide a complete solution, end users can increase their productivity and gain greater control and protection over their processes.
This post was contributed by Graeme Proctor, product manager (single-use technologies), Parker Bioscience Filtration, United Kingdom
Parker Bioscience Filtration specializes in automating and controlling single-use bioprocesses. By integrating sensory and automation technology into a process, a manufacturer can control the fluid more effectively, ensuring the quality of the final product. Visit www.parker.com/bioscience to find out more.
17 Jan 2019
Mycoplasma contamination events, although rare, can have an enormous and immediate negative impact on biomanufacturers leading to reduced productivity and delays in products reaching patients.
Parker Bioscience Filtration will be examining how to implement a holistic approach to the prevention of Mycoplasma contamination in an upcoming webinar entitled: The Prevention and Control of Mycoplasma Contamination in Bioprocessing which will take place on January 15, 2019, at 3 p.m. London time/10 a.m. New York time.
Here presenters Guy Matthews, global market development manager, and Dr. Carolyn Heslop, technical support group team leader, answer common questions on the threat posed by Mycoplasma contamination and how this can be tackled by biopharmaceutical manufacturers.
What are the potential consequences of Mycoplasma contamination?
“Short-term consequences for a biopharmaceutical manufacturer can include unplanned downtime and lost batches. This can result in the supply of pharmaceutical products to patients being affected. In the long term, there may be financial consequences through a loss of confidence in the manufacturer and a resulting decline in the company’s stock value.”
— Guy Matthews
Why does Mycoplasma contamination pose such a risk in biopharmaceutical manufacturing processes?
“As Mycoplasma can infect mammalian cell cultures through adhesion and subsequent fusion to cell membranes, this allows them to exploit the conditions and synthesized molecules provided by the host cell. This means that detection and quarantine procedures must also be implemented around cell lines. Mycoplasma can vary in size and shape from 0.2 microns upwards, have no peptidoglycan cell wall and exhibit pleomorphism (the ability to alter size and shape in relation to environmental conditions). This means that they are capable of penetrating sterilizing grade filtration systems.”
— Dr. Carolyn Heslop
What steps should biopharmaceutical manufacturers consider in combatting this threat?
“Start with the basics: employing the standards of Good Laboratory Practice. Considering factors such as the storage and packaging of media, and understanding the nature of the supply chain are all important factors in mitigating the risk of Mycoplasma contamination. Identifying where contamination is likely to originate from and mitigating the risk at the source can prevent problems further on in the process. Gamma irradiation or heat inactivation to eliminate Mycoplasma present on gamma or heat-stable incoming raw materials can be used to guard against contamination. However, not all media components can be heated or subjected to irradiation. Therefore, filtration has a vital role to play in combating contamination during the biopharmaceutical process. Biopharmaceutical manufacturers should consult with their filter suppliers on issues such as filter sizing to ensure that their filtration systems are optimized appropriately."
— Guy Matthews
What kind of filtration system is needed?
“In order to effectively control Mycoplasma, the use of a Mycoplasma retentive 0.1 micron filter – such as Parker's PROPOR MR – is recommended. However, as the filter is twice as tight as a standard 0.2 micron sterilizing grade filter, pressure levels in the process can be a major concern. Filters may not function effectively if the flow is too rapid – for instance when pressure peaks occur.”
— Dr Carolyn Heslop
Is there a solution to this challenge?
“Biopharmaceutical manufacturers could consider implementing an automated single-use system. This ensures that critical process parameters such as pressure levels can be constantly monitored, ensuring the process stays within the validated process limits. An automated single-use system will also remove the possibility of human error – and give manufacturers more control over the process.”
— Guy Matthews
Sign up for our webinar and learn how to mitigate the risk of Mycoplasma contamination
For more information on the advantages of single-use technology in mitigating the risk of Mycoplasma contamination and how to implement a holistic approach to the prevention of Mycoplasma contamination, register for Parker Bioscience Filtration’s forthcoming webinar: The Prevention and Control of Mycoplasma Contamination in Bioprocessing. The webinar will take place on January 15, 2019, at 3 p.m. London time/10 a.m. New York time.
This post was contributed by Guy Matthews, global market development manager, and Dr Carolyn Heslop, technical support group team leader, at Parker Bioscience Filtration, United Kingdom.
Parker Bioscience Filtration specializes in automating and controlling single-use processes. By integrating sensory and automation technology into a process, a biopharmaceutical manufacturer can control the fluid more effectively, ensuring the quality of the final product.
7 Jan 2019
Many companies, including those in the food and beverage, pharmaceutical, cosmetics, manufacturing and electronics industries, recognize the negative effects on quality created by oil contact with their product during production. Product rejections and consumer safety concerns associated with oil contamination can have broad negative financial and commercial impacts on a company. However, an often overlooked source of oil in compressed air — ambient air — is frequently misunderstood, underestimated or ignored.
In this blog, we’ll examine the effect that ambient oil vapour levels can have on downstream compressed air quality and what to consider when looking for technically oil-free compressed air to ISO8573-1 Class 0 or Class 1 for total oil.
What is ambient air?
Ambient air is the air we breathe and it’s all around us. It’s also the air that is drawn in by air compressors. Ambient air is made up of approximately 78% nitrogen and 21% oxygen. The remaining 1% contains a mix of argon, carbon, helium and hydrogen as well as a variety of contaminants — oil vapour being one of them. Ambient air is an often overlooked source of contamination that can have a big impact on a compressed air system.
How is ambient air contaminated?
Ambient air quality is directly impacted by air pollution caused by industrial processes such as burning fossil fuels and emissions from vehicle exhaust, oil and gas fields, paints, and solvents.
Oil vapour in ambient air is made up of a combination of hydrocarbons and volatile organic compounds (VOC). Ambient air typically contains between 0.05mg/m3 and 0.5mg/m3 of oil vapor, however, levels can be higher in dense, urban or industrial environments or next to car parks and busy roadways.
These levels may seem negligible, but when it comes to compressed air contamination, we must consider the effect that compressing the air has on the ambient contamination, the amount flowing into the compressed air system, and the time the compressor is operating.
Compressing air – compounding the problem?
The process of compression, as well as flow rate and time, build the level of oil in the compressed air that travels through a production system — air that eventually finds its way to production equipment, instrumentation, products and packaging materials.
Compression, or pressurizing the compressed air, can significantly increase the volume of oil. The greater the operating pressure, the higher the potential level of oil in the compressed air. This is compounded by the flow rate and time of operation. Compressors are often designed to operate continuously. This means that the concentration of oil continues to multiply in the confined space of the compressed air system. In turn, it will only exit the system at points where the air is released. These exit points are often in areas where the contaminated air comes in contact with product, production equipment or instrumentation. So, what may seem like negligible levels of hydrocarbons and VOC in ambient air, can become a great concern when the same is drawn in and compressed for use in manufacturing.
Effect on quality
Once inside the compressed air system, oil vapour will cool and condense, mixing with water in the air. This contamination causes numerous problems to the compressed air storage and distribution system, production equipment and final product leading to:
Due to the financial and commercial impact of contaminated product, many companies specify the use of an oil-free compressor, in the mistaken belief that this will deliver oil-free compressed air to critical applications.
Oil-free compressed air systems are typically installed without downstream purification equipment intended to remove oil, as they are deemed unnecessary accompaniments. While it is true that oil-free compressed air systems will not contribute contamination in the manner that oil lubricated systems will, oil vapour from ambient air remains untreated.Considerations for technically oil-free air
Technically oil-free air, in accordance with ISO8573-1 (international standard for compressed air purity) Class 0 or Class 1 for Total Oil, can only be guaranteed through the proper application of downstream purification equipment. This equipment may include water separators and coalescing filters to remove liquid water and oil, aerosols of water and oil, and solid particulate as well as adsorption filters to treat oil vapour. Compressed air users seeking an oil-free source of air would be wise to consider these precautionary purification steps, whether they are used with oil-lubricated or oil-free compressed air systems.
In order to establish compliance with ISO8573-1 Class 0 or Class 1, the international standards categorizing oil level in compressed air, users must perform tests to assess both oil aerosol and oil vapor presence in their systems. The levels of each phase will combine to establish total oil in the compressed air system.
To conduct the tests, samples of each phase must be drawn through a solvent extraction process and analyzed using gas chromatography (GC) or Fourier transform infrared (FT-IR) technology. The combination of the two methods will provide an accurate reading down to 0.003mg/m3.
While there are other methods for testing oil levels, like Photo Ionisation Detector (PID), these will leave certain compounds undetected. To this end, they should be used for estimation purposes only. GC and FT-IR will provide results that can be related to ISO standards with reliable and complete accuracy.
Parker has recently introduced a new compressed air purification system. The OFAS Oil Free Air System is a fully integrated heatless compressed air dryer and filtration package suitable for use with any compressor type and can be installed in the compressor room or at the point of use. Fitted with a third adsorbent column for oil vapour removal, the OFAS has been third-party validated by Lloyds register to provide ISO 8573-1 Class 0, with respect to total oil from both oil-lubricated and oil free compressors, ensuring the highest quality air at the point of use for critical applications.
Compressed air is vital to any production process. Whether it comes into direct contact with the product or is used to automate a process, a clean, dry reliable compressed air supply is essential. If the compressed air contains oil, the consequences can be high both financially and in terms of brand damage.
This blog was contributed by Mark White, compressed air treatment applications manager, Parker Gas Separation and Filtration Division, EMEA.
13 Nov 2018
One of the challenges faced in any biopharmaceutical process is bioburden control and containment — or how do you keep what is out, "out" and what is in, ‘"n".
For a stainless steel-based manufacturing system, the process is well understood. The lines are set up, the CIP and SIP cycles are run, the appropriate valves are closed and the system is pressurized and then left for a period of time, perhaps overnight, while it is monitored for pressure decay. If the pressure decay is minimal, you have an integral system.
If you tried this method with a single-use system, assuming the bag could take the pressure, at a minimum you would see losses from the tubing as it is a porous material which has a diffusion rate. Identifying a fail in a single-use system based on pressure decay, therefore, becomes difficult. The question is, is the decay due to a leak and therefore a faulty assembly or is it diffusion across the tubing material on an assembly that is intact and fit for use? Commercially available systems are now available which will provide the answers.
Integrity testers or leak detection systems?
A key point for discussion is: should the biopharma industry be talking about integrity testers or should we be talking about leak detection systems? This is an important difference due to the weight this industry places on the word integrity, especially if we talk about integrity tests.
If we use the language of integrity testing, it implies a level of security backed up by validation and a clear binary result. The meaning in this context is well defined and if a system fails an integrity test, a batch ultimately could be rejected, pending any rework or investigation.
At the post integrity testing stage, you can report that a sterilizing grade filter is integral or is not by using recognized and validated methods. However, it may be more difficult to make the same statement for a single-use assembly.
As an industry, we should be sure what integrity means in this context and how it should be described.
Leak detection on a system requires and allows for the interpretation of the results. Of course, if the interpretation is backed up by the manufacturer’s validation package then so much the better. The questions that are open are:
There is no need, however, to revert to stainless steel in bioprocessing operations. Stainless steel is not without its own challenges and potential points of weakness. The connections on a system, many of which are not used in a process — for example blanking ports on a vessel — all need to be assembled and tested. The stresses and strains, when going from ambient temperature to 121oC and back again, which are put on stainless steel systems, are avoided in single-use.
But we should be very clear about what we are testing and what those test results mean, so as not to create a false sense of security. The impact of simply assuming a single-use assembly is integral when there is no knowledge of how testing has been carried out can have serious consequences for a biopharmaceutical manufacturer.
We should also be challenging the vendors of single-use systems to ensure that the facilities and processes used to build and ship assemblies minimize any risk and that those processes are validated.
The old adage "you cannot test in quality, you must build it in", certainly rings true in this case.
13 Sep 2018