The Importance of Filtration in Process Operations
By Daniel Morosky, Rosedale Products, Inc.

Models 4, 6, and 8 can serve as bag filter, cartridge filter or basket strainer.

Filters, like valves and pumps, are common industrial components that are used everywhere.

The "behind the scene" nature of filter installations doesn't mean that filters' housings are bland. These pressure vessels are very important components in process operations worldwide and are often installed in extreme service conditions.

The variations in filter housings are limited only to the imagination. Because filter installations are seldom the same, custom features abound.

Industrial filter housings, in liquid and gas applications, range typically from 4" to 48" in diameter and are normally longer than they are wide. Mounting styles can be horizontal or vertical. Each has distinct advantages applicable to the specific installation.

Horizontal units are ergonomic. The access to the filter elements is close at hand, and many use "inside out" flowing elements to keep the solids on the inside. High flow style elements are 7 inches in diameter by 60 or 80 inches long and contain as much as 30 pounds of solids. The footprint for horizontal styles is larger than that of vertical pressure vessels.

Vertical vessels are better suited for use with standard bag filters and vintage tubular elements. Low profile designs keep facility costs down by not requiring a platform for accessing large diameter filter housings.

Industrial filter housings generally contain filter bags, filter cartridges, or basket strainers.

DESIGN
Critical filter housing criteria is design pressure and temperature, and material of construction. Once that is determined, one can look at other features.

MATERIALS
Filter housings are most commonly made in carbon steel, and types 304, and 316 stainless steel. High nickel alloys and titanium are routinely available. Polypropylene and PVDF are also manufactured in limited models.

PERFORMANCE
The degree of filtration determines the inside configuration of the filter housing. If the selection is coarse straining, then a basket with perforated metal or wire mesh inlay will suffice. This can be one large basket or many smaller baskets depending on ergonomics and logistics. Filter bag options are normally in multiple arrangements as are filter cartridges. The exception is that filter cartridges can be of several small diameter tubes, or larger high surface area pleated units.

LID STYLES
The basic closure lid styles are: V band clamp, eye nut rod end hatch assembly, clam-shell with hinge, hydraulic assist, mechanical quick clamp, blind flange, and threaded cap.

Depending on how frequently the device is to be serviced and project budget range, the closure style can be determined. Low-pressure service under 100 psi is popular for the selection of a V Band clamp. For more frequent filter changing, the more rugged eye nut rod end closure may be preferred. Larger diameter vessels use a davit swing arm as its standard lid access.

CONNECTIONS
The selection of available pipe connections is dictated by the individual application. NPT or ANSI flange connections dominate the U.S. market, but straight thread, butt weld, socket weld, Victaulic, European BSP and DIN are readily available.

Every filter vessel should be equipped with a drain and vent connection as well as differential gage ports.

CODES AND STANDARDS
Filter housings are designed in accordance with ASME pressure vessels code with varying degrees of specificity. Optional standards can include conformance to Canadian and European codes. Critical service often requires corrosion allowance, radiography, post weld heat treatment, liquid penetrate test and others.

Rosedale Products' line of filter housings offer everything stated above. Filter housings with connections from Þ" to 30" are standard. Each vessel can be configured to be a bag filter, cartridge filter, or a basket strainer, and in some cases both. Below is a brief description of some of the standard line and custom housings.

MODELS 4, 6, and 8 BASKET STRAINERS
Strainers or Filters: Your Choice!

Rosedale Models 4, 6, and 8 are single unit housings that can be configured to meet a vast amount of filtration needs. These industry standard housings allow use as a strainer or filter without any type of modification. Piping configurations are variable to meet most system requirements.

MODEL NCO and NLCO BAG
Low cost filter housings for flow rates to 100 gpm.

NCO high-capacity bag filters offer an exceptional value in basic filtration applications. Offered in trade sizes 1, 2, and 12, the NCO is also available with the 700 cartridge series.

NCO housings provide large dirt-holding capacity combined with a rugged design rated to 150 psi. The housings incorporate an eye-nut cover that is easily removed, reducing time spent on bag or cartridge change-out. The NCO bag housing offers versatility for any piping arrangement, utilizing uni-style design (side and bottom outlet). Two connection sizes are available for both bag and cartridge filters.

The NCO housings are electro-polished creating a smooth, easy-to-clean surface.

Multi-basket strainers and multi-bag filters

Plastic PVDF/Polypro Model 8 bag filter housing

ALL PLASTIC PVCF/POLYPRO
Excellent for use in pure, ultra-pure and corrosive applications.

The Rosedale Generation II filter housings incorporate a unique one-piece, seamless body that handles flows to 100 GMP. It is rated to 100 psi at 150 F, and offers excellent resistance to corrosion. In addition Rosedale has added new features.

An easy to remove cover and basket make bag change-out quick, clean and simple. No special tools are needed, and the filter is back in service in a matter of minutes.

ROSEDALE MODEL HSS and HSS750
Single Cartridge Housings for Liquids:

The Rosedale Model HSS single element filter housing is an all stainless steel unit ideal for general industrial service. It features a ring-nut closure (HSS) or bolt closure (HSS750) for easy access to the head and cartridge sump.

The HSS is available in 10" or 20" cartridge models. HSS units are rated for 150 psi service at 200 F. HSS750 units are rated for 750 psi service at 200 F. Flow rates to 30 GPM.

MULTI-BASKET MODELS offer a wide range of flow capacities and contaminant-holding capabilities. They contain 2 to 23 same-size baskets and can handle flows from 400 to 4500 GPM. Multi-cartridge housings contain 2-205 cartridges.

DUPLEX MODELS are two housings that are piped together for alternate use, providing continuous operation, reducing operating costs. Flow is switched back and forth between the filter housings, allowing one side to be serviced while the other is in use. One lever actuates all valves simultaneously. All Duplex Models are also available in a trouble-free automatic service system.

PORTABLE FILTRATION SYSTEMS
The perfect choice for batch processing or filtering from tanks of drums.

This cart-mounted filter system has a diaphragm pump, pneumatic components and valves. The housing itself uses a standard size 12 bag. The clamp cover is easily removed and helps to reduce the time spent cleaning or replacing the bag. Rosedale's superior side-entry design does not allow contaminant by pass around the filter bag nor fluid to impinge the filter bag. It also prevents the spills and messes caused when opening.

In-line solids/liquids separators

SOLIDS/LIQUIDS SEPARATORS
In-Line Separators for Industrial Applications:

Use Rosedale's centrifugal-action separator to remove grit, sand, metal chips, fines, and other solids from liquids. They're perfect for use as a pre-filter to extend the life of fine filtration systems. These units require little or no maintenance, as there are no moving parts to wear out, or filter media to replace. The unit only requires a simple purging, eliminating downtime. It is made for flows from 6 GPM and retention ratings to 50 micron.

CUSTOM HOUSINGS AND TANKS
Rosedale can build anything from simple modifications on standard housings, to customer specified skid-mounted filtration systems. These can incorporate filters, strainers, separators, controllers, sensors, and automated operations and the options are numerous. The company also manufactures tank diameters to 8 feet.

Rosedale has a long history of innovative filtration designs. They are as simple as the Model 4 Housing or as complex as the multi-station Automatic Backwashing Filtration Systems. Using their expertise, the company works with clients to manufacture systems that meet all their requirements. Some of their current standard models started out as solutions to a client's need, such as the duplex and multiplex filters or convertible housings. The company designs housings on a daily basis, and is ready to meet any client's needs. Rosedale has developed systems that meet the demanding requirements of the metalworking industry, environmental water reclamation industry, and solids recovery process.

For more information contact:
ROSEDALE FILTRATION PRODUCTS, INC.
10863 Portal Drive | Los Alamitos, CA 90720 USA
Tel: 800-821-5373 or 734-665-8201 | Fax: 734-665-2214
Email: filters@rosedaleproducts.com | Website: www.rosedaleproducts.com