Filter Bag Housings: How Do Filter Bag Housings Work
filter bag housings are a critical component in industrial filtration systems. These sturdy metal or plastic vessels enclose the filter bags that remove solids and contaminants from liquids and gases. Choosing the right filter bag housing for your application is key to maximizing performance and equipment life.
How Do filter bag Housings Work?
filter bag housings contain cylindrical filter bags made of woven or felted fabric. The contaminated fluid enters the housing and flows from the outside to the inside of the bags. Solids collect on the outer surface while clean fluid passes through the bag material into the housing center. This filtered fluid then exits the housing.
The bags are periodically cleaned by pulsing reverse air flow. This knocks the collected solids off the bag surface so the filtration process can continue. filter bag housings allow easy access to the filter bags for inspection, replacement, and maintenance.
Key Benefits of Using filter bag Housings
High filtration efficiency for both liquids and gases
Filter bag housings excel at removing contaminants and solids from both liquids and gases. Their high filtration efficiency results from the cylindrical shape and large surface area of the filter bags. As fluid passes from the outside to the inside of the bag, particulates are captured throughout the depth of the fabric. This allows them to operate as both a depth filter and screen filter in one. Efficiencies of 98% or higher can be achieved with proper bag selection and housing design. The same housing can filtrate particles from 10 microns down to 100 nanometers by utilizing filters of different porosity. Whether you need to clarify liquids or purify air, a filter bag housing optimizes filtration performance.
Can accommodate various filter media types
One benefit of bag style filters is their compatibility with numerous filter media. filter bag housings can utilize woven fabrics, felts, membranes, synthetics, and more. Media can be tailored for specific temperatures, chemical environments, or particle sizes. Elements can be single-use disposable or cleanable and reusable.
Polypropylene, polyester, nylon, Teflon, nomex, and fiberglass are common materials used. Pleated or non-pleated bags are available. Multi-bag housings allow mixing of different media to optimize the filtration. This media flexibility lets you configure your ideal filtration system.
Bags are cleanable for long service life
While surface filter media can load up with solids and require frequent replacement, filter bags can be cleaned for extended use. When the pressure drop indicates solids have accumulated, pulses of reverse air flow dislodge the cake and restore the bag. Media selected for resistance to blinding can often be cleaned hundreds of times before needing change-out.
This cleaning via pulses of air allows long service life from the filter media, saving on replacement costs. Though the bags eventually wear, regular cleaning extends the useful life dramatically. The cost savings of reusable filter bags make them an economical choice.
Simple bag replacement when needed
When filter bags do require change-out, replacement is a simple process with filter bag housings. The vessel cover is removed, spent bags are taken off their attachment collars, and new bags installed on the collars. Only the inexpensive filter media is discarded while the housing is reused. No tools or expertise are needed to swap in fresh bags.
Keeping spare bags on hand allows quick restoration of the filtration system if media becomes damaged or excessively dirty. The straightforward bag replacement makes maintenance fast and easy compared to replacing entire filter cartridges.
Allows filtration of high solid load fluids
Filter bag housings excel when filtering liquids with high amounts of contaminants and solids. The depth filtration action traps particulates throughout the volume of the bag instead of just on the surface. The large filter area of multiple bags handles high concentrations of solids. As filtration proceeds, pulsing the bags removes the built up filter cake so the process can continue.
Though solids eventually overwhelm single-use filters, filter bags can be repeatedly cleaned to handle feeds with extremely high amounts of contaminants. This capability makes them well suited for waste streams, chemical processing, and other dirty applications.
Customizable for specialized applications
While standard filter bag housings handle many basic needs, the ability to customize them is a key advantage. Housings can be fabricated from exotic alloys for extreme temperatures and corrosion resistance. Multi-bag vessels allow segmented zones with different filter types. Special coatings, valves, and clean-in-place features can be added.
Housings can be designed for sanitary applications. Unique shapes fit existing footprints. With customized options, filter bag housings can meet the specific needs of specialized processes and industries. Work with your supplier to create a tailored filtration system.
Durable construction for rugged environments
Filter bag housings are built to take punishment in harsh industrial settings. They are constructed from robust materials like carbon steel, stainless steel, fiberglass, and CPVC plastic. These housings stand up to high pressures, temperatures, and flow rates. Anchor points allow stable installation. Thick walls resist damage from physical impacts. The tough exterior protects the filter bags inside, extending their usable life.
Gaskets, welds, and seals maintain integrity. While the interior filter bags require care, the housing itself is designed for years of reliable service with minimal maintenance. The rugged exterior keeps your filtration system operating in challenging conditions.
Cost-effective for high filtration capacities
For high volume filtration applications, filter bag housings are an economical choice compared to cartridge or other filter types. Their inexpensive filter media, cleanable bags, and large hold-up volume make them very cost effective. Housings last for decades while filter bags are periodically replaced at reasonable expense.
The high flow rates and efficient usage of filter area minimize the number of vessels required. Savings add up from lower capital investment, smaller footprint, reduced labor, lower filter consumption, and lower disposal costs. When correctly applied, filter bag housings provide excellent value for challenging, high-capacity filtration tasks. Their superior performance and lower overall cost make filter bags a key part of cost management.
Types of filter bag Housings
Single bag housings enclose one large filter bag for simple filtration needs. Multi-bag housings allow rows of different sized bags to be used in the same vessel. This maximizes the filter area for higher flow rates.
Housings can be designed for low or high pressure operation. Horizontal or vertical configurations are available. Housings come in carbon steel, stainless steel, and various plastic materials.
Applications for filter bag Housings
filter bag housings are commonly used for:
Pre-filtration in reverse osmosis systems
Reverse osmosis relies on membrane filters to remove contaminants and purify water. However, the RO membranes require extensive pre-filtration to operate efficiently and prevent fouling. filter bag housings equipped with 1-5 micron filter bags provide excellent RO pre-filtration. The depth filtration action protects the delicate RO membranes by capturing particulates, organics, colloids, and oxidants.
Multi-bag housings allow stepped filtration with progressively finer media. The high dirt holding capacity handles fluctuating feed quality. Automated pulsing cleans loaded filter bags. filter bag housings maximize uptime and minimize replacements of expensive RO membranes when utilized as pre-filters.
Final filtration of processed liquids
As a final polishing step, filter bag housings remove traces of contaminants and particulates down to 0.5 microns or less. Final filters protect downstream processes and ensure purity standards are met. Pharmaceuticals, chemicals, beverages, and heat transfer fluids often undergo a last filtration by filter bags. The all-liquid design prevents product loss versus gas-blown filters.
The extensive filter area of multi-bag housings handles high flow rates. Automated systems continually clean the filter bags for consistent performance. For final clarification of processed liquids, properly designed bag housings deliver exceptional results.
Clarifying oils and solvents
Filter bag housings help recover and reuse expensive solvents, hydrocarbons, and lubricating oils. Removal of soot, waste products, and other contaminants lets oil be recycled. A single pass through a bag housing can clean and clarify dirty oil very effectively. The high temperature resistance and excellent solvent compatibility of filter media allows effective filtration.
Housings in carbon steel or stainless steel handle hot oil feeds. The vessels can be steam jacketed or traced for heat if needed. For high purity requirements, double filtering through two housings ensures optimal cleanliness. Keeping oils clean with bag filtration extends fluid life, prevents fouling, and saves money.
Removing dust from air streams
Industrial plants often utilize filter bag housings to remove dust from large air volumes. The cylindrical filter bags provide extensive media area for gas flow with low pressure drop. Dust particles from metalworking, combustion exhaust, or material handling cling to the outside of the filter bags. Periodic pulses of reverse air shake the filter cake off so gases keep flowing.
Well-designed systems emit clean air with minimal particulate emissions. Choosing filter media compatible with the dust prevents bag blinding. filter bag housings provide efficient two-stage air filtration when paired with cyclones or inertial separators. Keeping plant air clean improves safety and product quality.
Recovery of solid products from waste streams
Filter bag housing systems enable profitable recovery of saleable solids from waste discharges. Valuable materials like catalysts, carbon, metal powders, and pigments can be filtered from waste slurries. Multi-bag housings allow continuous high-volume filtration.
Solids are dried and removed as filter cakes. Automated shaker mechanisms facilitate cake discharge. The recovered materials can be recycled or sold rather than landfilled. Payback from the reclaimed solids can offset the filter system costs. Waste stream filtration with well-engineered bag housings cuts disposal expenses while generating income.
And many other industrial processes
Nearly any industry can benefit from bag filtration including food & beverage, mineral processing, petrochemical, pollution abatement, metal finishing, electronics, pharmaceuticals, water treatment, and more. Superior contaminant reduction, high capacities, and excellent filter lives make bag housings a versatile solution.
They remove everything from catalyst fines to coffee grounds. Well-designed filter bag systems withstand temperatures from -20°F to over 500°F. With customized features, filter bags can meet specific process needs. And new filter media developments continue expanding their capabilities.
If your liquid or gas stream needs reliable clarification, discover the benefits of filter bag housing systems. Call a Griffin Filters Engineer to find out more at 315-451-5300
Proper housing selection ensures your bag filtration system operates reliably and cost-effectively. Work with a knowledgeable filter supplier to choose the best configuration for your specific needs. Investing in high quality filter bag housings will pay dividends for years to come.