The FF-Series coalescing filters from Perma Pure are high efficiency particulate and coalescing filters designed for high temperature corrosive service. Used as a coalescer, this filter removes liquid droplets and particles down to 0.1 micron with an efficiency of 95% or greater. The thick, high capacity borosilicate glass and Teflon filter element uniformly drains coalesced liquids to the bottom of the housing, where they are evacuated through the 1/8″ NPT drain port. For particulates, the filter removes 95% of all particles 0.1 micron or greater, with a low pressure drop and long element life.

Coalescing filtration is achieved by forcing the gas stream through the filter element (see illustration). The flow path shown reflects a coalescing application. In this situation, small aerosol particles are forced together as they pass through the fine inner layer of the filter element. The larger drops created in this process fall out of the gas stream due to their mass. This natural separation is assisted by the coarse drain layer on the outside of the filter element. In a particulate application, this filter can be installed to reverse the flow path shown. The captured particulate then collects on the outside surface of the element, permitting visual determination of element condition.

FF-250 Series Coalescing Filter Specifications

FF-250 Series Filter Maintenance Items

FF-250 Series Filter Maintenance Procedure

All coalescing/ particulate filters should be checked regularly to ensure that the element is in good condition. The element should be replaced if it appears to be dirty or begins to cause a flow restriction in the system.

Common Spare Parts and Maintenance Items

For end users of our Sample Conditioning Systems, we have created a simple list of common spare parts and maintenance items available for them. Contact us for a quote or to  place an order for these items today.

AS-Series Ammonia Scrubber Media Replacement Part Numbers

FF-250 Series Coalescing Filter Maintenance Items

HD Series Heatless Dryer Maintenance Items

DM Series Desiccant Membrane Dryer Maintenance Items

AS-Series Acid Scrubbers Media Replacement Part Numbers

 Perma Pure Nafion Systems Maintenance Items

Baldwin Series Sample Probes – Model 32C, 33C, 33XP, 34C, 35C, 45
O-Ring: Pack, Viton, All probes, 5 ea 1⅞” OD, 2 ¼” OD – 3PAM-031PK
Filter element: Ceramic 2 micron (Note: Other types available upon request) – 3FEC-002
Gasket: graphoil 1.25” (10 pack) – 3PAM-006PK

Baldwin Sample Coolers and Conditioning Systems
Peristaltic pump, tubing, norprene, size 17 (10 feet) – 2PBT-002PK
Paste,Thermal,Compound,2 Oz.Tube – 0PTC-003
Impinger Fittings- Kynar
Connector,Kynar,1/4″Tx1/4″MPT – 100172   Note: Inlet fitting used for ¼” sample line
Connector, Kynar, 3/8″Tx1/4″MPT – 2FTK-009   Note: Inlet fitting used for 3/8” sample line
Elbow, Kynar, 1/4″, 1/8″ NPT – 100269   Note: Outlet of first impinger
Elbow, Kynar, 1/4″, 1/4″ NPT – 100848   Note: Inlet of second impinger
Connector,Kynar,1/4″Tx1/8″MPT – 100171   Note: Outlet of second impinger
Adapter,Kynar,3/8″MPTx1/4″Barb – 2FTK-010   Note: Liquid drain fitting; 1 per impinger
Peltier element kit, 40 mm – 3KPE-004
Sample pump repair kit, single head – 2PAM-001
Sample pump repair kit, dual head – 2PAM-002

by David A. Leighty, President

Increasingly stringent environmental regulations for stack gas emissions are forcing more industrial operations to install elaborate Continuous Emissions Monitoring Systems (CEMS). Unfortunately these systems often suffer performance or reliability limitations due to the problems with sample conditioning. A new technology has overcome this difficulty, even for a challenging CEMS task like hydrogen chloride (HCl) analysis. This new conditioning system is intended to accept virtually any hot, wet, dirty sample and transform it into a cool, dry, clean sample ready for analysis.

Removal of water is typically the problem. Until recently the preferred sample clean-up method has been condensation within a chiller system, followed by collection of water and other coalescable liquids. Unfortunately chiller/condensation systems have numerous limitations, in particular loss of water-soluble analytes, as well as difficulty with samples that are highly corrosive or that have very high water content or flow rate. Since chiller/condensation systems normally operate above freezing, at least 0.6% water remains in the sample even under the best circumstances.

A pharmaceutical manufacturer in North Carolina discovered chillers are sometimes inadequate to the task. The company monitors their stack gas emission of HCl then neutralized the HCl with lime to comply with permit conditions as part of their “green” (environmentally friendly) policy. The gas filter correlation analyzer for HCl used at their research and development facility in Research Triangle Park worked only sporadically without sample conditioning because water in the sample corroded the gold-filled mirrors in the system, requiring frequent replacement at an approximate cost of $900.

Dilution of the sample with dry air to reduce the water content of the sample proved ineffective because the HCl content in the diluted sample could not be detected. Installation of a chiller would not solve the problem; since HCl is highly water soluble, it would pass down the drain with the condensate instead of into the analyzer.

The solution was a Gas Analysis Sampling System (GASS™) from Perma Pure Inc. The GASS device utilizes a Nafion gas dryer to very selectively absorb water vapor from stack gases. Nafion® is a corrosion-resistant fluoropolymer that functions as a semi-permeable membrane to water vapor. The system removes water from the sample stream while still in the vapor phase, so there is no contaminant loss of water-soluble gases such as HCl. Dew points as low as -25°C (corresponding to only 600 ppm of water) are achieved while handling sample flow rates up to 25 liters per minute.

The GASS-II system quickly proved its merits at the pharmaceutical facility by restoring the gas filter correlation HCl analyzer to operation. Elimination of HCL losses during sample conditioning dramatically improved the accuracy and precision of the analysis. When the water content of the sample dropped substantially, the mirrors inside the analyzer ceased corroding, eliminating frequent mirror maintenance. According to one plant engineer, the GASS-II system paid for itself in just a few months based on this benefit alone.

Once the results became more accurate and reliable, the analyzer could also be used as a process control device in addition to environmental monitoring. Lime was originally added in excess to control the HCl in the stack gas emissions. Continuous HCl monitoring permits more accurate lime additions, eliminating waste and expense. In the Coalescing/Filtration Zone, The sample is equilibrated to the desired temperature regardless of its initial temperature. Particulate and high-boiling point liquids such as sulfuric acid (if present) are then removed by a coalescing filter with an automatic drain. In the Drying Zone, the sample temperature is raised slightly before introduction in the dryer(s).

Pharmaceutical processing is not the only industry benefiting from the GASS system. Although hydrogen chloride and sulfur dioxide are particularly water soluble, even nitrogen oxides are moderately water soluble and are consequently lost when passed through a chiller/condenser system. Nearly every CEMS location is required to monitor one or more of these gases. Utilities, refineries and other major industries are now turning to the GASS systems as an alternative to chiller/condensation or dilution systems to achieve more accurate, reliable CEMS data.

Another reason many industries are turning to the GASS-II system is its adaptability. A wide range of options are available to tailor the system to any particular application. The transformation of a hot, wet, dirty sample into one suitable for analysis is accomplished in stages as the sample passes through three zones within the system: Coalescing/Filtration, Drying and Control.

In the Coalescing/Filtration Zone, the sample is equilibrated to the desired temperature regardless of its initial temperature. Particulate and high-boiling point liquids such as sulfuric acid (if present) are then removed by a coalescing filter with an automatic drain. In the Drying Zone, the sample temperature is raised slightly before introduction in the dryer(s). The temperature is then steadily reduced to ambient levels. Water is removed at the same time, so the sample remains non-condensing as it exits into the final zone. In the Control Zone, drying is completed; the sample can ten pass through unheated tubing to the analyzers without risk of condensation. Also included in this zone are flow controls for the dryer purge air. The entire assembly is mounted with an environmentally sealed enclosure for trouble-free fieldd installation.

While not perfectly selective, the GASS-II system avoid losses of most analytes of significance in CEMS applications. Among the compounds typically monitored, only ammonia is lost through the Nafion dryer while water is being removed. As monitoring requirements become more stringent, condensation sytems used for CEMS are proving more problematic, with unacceptably high analyte losses, high residual water, and attendant reliability problems. As a product incorporating new technology that overcomes these shortcomings, GASS systems have proved their suitability for CEMS applications.

Mini-GASS™ systems prepare hot gas sample streams for high performance gas analysis.

• 12″w x 28″h x 7″d fiberglass enclosure w/transparent cover
• 1/4″  inlet compression fitting
• Heat-shrinkable conduit for heated sample line inlet
• PID temperature controller with digital display
• Purge gas flowmeter, pressure regulator and pressure gage
• System ready/alarm outputs
• Corrosion-resistant coalescing filter, 2.5″ diameter housing with borosilicate glass shell; filter element of borosilicate fiber in Teflon® binder with 1 µm absolute porosity
• Rated NEMA/ Type 4X
• CE Mark approved

MG-1228P Probe mounted Mini-GASS system incorporates all the features of the std MG-1228 along with a heated probe filter, heated blowback and probe in a NEMA 4X fiberglass enclosure.

Perma Pure MiniGASS 1228P Probe System Recommended Accessories

Perma Pure MiniGASS 1228P Probe System Spare Parts

Mini-GASS™ systems prepare hot gas sample streams for high performance gas analysis.

• 12″w x 28″h x 7″d fiberglass enclosure w/solid cover
• Heated probe filter assembly
• PID temperature controller with digital display
• Purge gas flowmeter, pressure regulator and pressure gage
• System ready/alarm outputs
• Corrosion-resistant coalescing filter; borosilicate fiber in Teflon® binder element 1 µm absolute porosity
• Calibration gas inlet port
• NEMA / Type 4X rated
• CE Mark approved

MG-1228W Wall Wall mounted Mini-GASS system incorporates all the features of the std MG-1228 along with a heated probe filter, heated blowback and probe in a NEMA 4X fiberglass enclosure.

Perma Pure MiniGASS 1228P Probe System Spare Parts

Mini-GASS™ systems prepare hot gas sample streams for high performance gas analysis.

• 12″w x 20″h x 7″d fiberglass enclosure w/transparent cover
• 1/4″ inlet compression fitting
• Heat-shrinkable conduit for heated sample line inlet
• PID temperature controller with digital display
• Purge gas flowmeter, pressure regulator and pressure gage
• Corrosion-resistant coalescing filter, 2.5″ diameter housing with borosilicate glass shell; filter element of borosilicate fiber in Teflon® binder 1 µm absolute porosity
• NEMA-4X rated
• CE Mark approved

MG-1220 The low-cost Mini-GASS system which incorporates sample filter, Nafion dryer, temperature and purge controls, safety interlocks and optional heatless dryer.

Perma Pure MiniGASS 1220 Recommended Accessories

Perma Pure MiniGASS 1220 Spare Parts

Perma Pure HD-Series heatless dryers are ideal for low flow air drying operations. Dryer operation is fully automatic, and outlet dew points as low as -50°C can be achieved.

HD Heatless Desiccant Dryers dryers consist of two chambers filled with highly adsorbent desiccant. The standard desiccant is molecular sieve 4A. One chamber dries the gas stream while the opposite chamber is regenerated (purged). Purge air is a small portion of dried air taken from the drying chamber, expanded to atmospheric pressure and flowing counter-current through the regenerating (wet) chamber. Wet purge air is released from an exhaust port in the vapor state so that no drain is required. Purge air volume is controlled with an orifice housed within the unit. Purge air may be vented directly into the surrounding atmosphere, or it may be piped to a remote location. Once electrical power and air pressure are supplied to the dryer, it is ready to be used.

There are two models available. The 7″ model is best for flows under 60 liters per minute, while the 12″ version is recommended for flows of up to 90 liters per minute. The 12″ model is also recommended for applications requiring dew points below 40°C.

Electrical Connection

The Heatless Dryer requires 110 VAC/60Hz or 220VBAc/50Hz, depending upon model.

Piping Connections

A compressed air line supplying between 60 psig and 100 psig should be connected to the 1/4″ wet air inlet port located between the two solenoid valves. The 1/4″ polypropylene compression fitting is the dry air outlet port. This should be connected via 1/4″ tubing. If the length of tube exceeds 15 meters, 3/8″ tubing should be used. The purge air exhaust ports located at the center of the solenoid valve coil should be left open to the atmosphere to provide venting for the wet air exhaust. They can be piped to a remote location if desired. An inexpensive particulate after-filter may be used on the purge air exhaust to reduce noise.

Operation

Once electrical power and air pressure are supplied to the dryer, it is ready for use. The dryer will operate indefinitely assuming a few precautions are taken. The number one cause of failure is compressor oil contamination of the drying media. A coalescing oil/water pre-filter is recommended for installations where oil or water mist is present.

HD Series Heatless Dryer Maintenance Items

FB-Series bypass filters are inertial separation filters for high particulate load applications. Used upstream of fine particulate filters, FB filters greatly increase the life and performance of particulate and coalescing filters. Flow can be passed through under pressure or pulled through under vacuum. Perma Pure offers a compressed air-driven eductor and a heating system as options.

Inertial Bypass Filter

Large volumes of high-velocity, particulate laden gas pass straight through the filter element (see illustration). Sample is drawn from the bypass flow through a port which is perpendicular to the main flow. Pulled off the bypass stream, the sample is filtered by the mesh or porous filter element. The bulk of the particulate passes directly through the length of the filter element due to its high velocity and inertia, which prevents particulate from being diverted by the pull of the sample outlet port. Any particles that are pulled to the sample outlet are filtered by the element. The high velocity flow also continuously flushes the filter element, reducing pore clogging.

For applications involving a high temperature, wet sample, Perma Pure offers bypass filter heating systems. This involves a simple electrical resistance strip heater mounted in a piece of steel channel. The temperature is controlled with a factory pre-set mechanical thermostat which switches electrical power on and off to maintain the desired setting.

Applications for Perma Pure FB-Series bypass filters can be found in both CEMS and process monitoring applications. In addition to reducing high particulate, these filters can be installed to reduce the response time of analyzers. A pump or vacuum eductor is used to pull the fast bypass sample through the filter thus reducing the response time when the sampling system is located some distance from the sample point. Since analyzers generally only require a sample flow of 1-2 lpm, the time required to pull the sample from the sample point to the analyzer would be excessively long without this fast bypass loop. This increases the life of conditioning systems. By virtue of its design the Perma Pure Bypass Filter, which is sometimes called an inertial filter, serves to eliminate large amounts of particulate and tends to be self cleaning.

FB-Series filters are available in two models: FB-625 and FB-1000. Flow rating for the filters is dependent on the particulate level of the sample. In general the FB-625 Series filters are suitable for sample flows of up to 10 liters per minute while the FB-1000 Series filters can handle higher flows.

All connections are female NPT

All seals are viton