Pleated cartridge filters

Figure 7.11 Cut-away view of a simple pleated cartridge filter. By folding the membrane a large surface area can be contacted with the feed solution producing a high particle loading capacity. (From Membrana product literature)...

Nassehi V., Hanspal N.S., Waghode A.N., Ruziwa W.R. and Wakeman R.J., 2005. Finite-element modelling of combined free/porous flow regimes Simulation of flow through pleated cartridge filters, Chem. Eng. Sci., 60, 995-1006. 

Cartridge filters Filters normally consisting of nonwoven V-pleated filter paper made into flat panels or cylindrical car-... 

Brake horsepower, centrifugal pumps, 200 Driver horsepower, 201 Burst pressure, 405, 456 Cartridge filters, 274-278 Capture mechanism, 279 Edge filler, 278 Filter media, table, 278 Micron ratings, 277 Reusable elements, 281 Sintered metal, 280 Types, 276, 277, 279 Wound vs. pleated, 276, 277 Centrifugal pumps, operating characteristics, 177-180 Calculations, see hydraulic performance Capacity, 180... 

Figure 6.24 Photographic representation of a range of filter types and their stainless steel housing. Most filters used on an industrial scale are of a pleated cartridge design, which facilitates housing of maximum filter area within a compact space (a). These are generally housed in stainless steel housing units (b). Some process operations, however, still make use of flat (disc) filters, which are housed in a tripod-based stainless steel housing (c). All photographs courtesy of Pall Life Sciences, Ireland...

Despite the limited volumes that can be treated before a filter must be replaced, microfiltration is economical because the cost of disposable cartridges is low. Currently, a lO-in.-long pleated cartridge costs between US 10 and US 20 and contains 0.3-0.5 m2 of active membrane area. The low cost reflects the large numbers that are produced. 

Disposable cartridge filters should be made of synthetic, non-degradable materials such as nylon or polypropylene. Their construction can be spun-bonded or melt-blown, string-wound, and pleated. These are described below. 

Pleated These cartridge filters are typically used in higher-purity applications, such as pharmaceutical and microelectronics. The filters can have a multi-layered construction or be single layer. Typical materials of construction include polypropylene, polyethersulfone, and borosilicate glass fiber. 

Figure 5. Gelman pleated crossflow filter cartridge. Cartridge components (A) a porous pleated support screen to provide mechanical support under applied pressure (B) the pleated microporous filtration element (C) the pleated spacer which creates the thin flow channel and promotes turbulent flow (D) the impermeable film which creates the flow channel (E) a porous support tube to provide an exit for permeate (F) open-end cap which provides for exit of product flow (G) closed-end cap completely which seals one end of module (H) outer seal ring which creates the seal between the impermeable film in the module and the interior of the housing. The back pressure support tube is not pictured. The ends of the cartridge are potted and sealed. A space between the ends of Film D and the end seals is provided to allow the entrance and exit of the flow-channel fluid.

Figure 17. Plugging test results a, pilot microscreen effluents b, filtrates from polishing by crossflow filtration through Ll-pm Acropor filter in axial filter (1.5 psi, 1000 rpm) and in pleated cartridge (loop).

Figure 1.33 Schematic diagram showing membrane modules presently used in industrial separation processes (a) pleated membrane filter cartridge (b) plate-and-frame membrane module (c) spiral wound membrane module (d) tubular membrane module (e) capillary membrane module (f) hollow fiber membrane module.

V.A. Bielobradek, Selecting a better media for your pleated bag and cartridge filter . Powder and Bulk Engineering 14 (2000)10, 77-81. 

Small disc filters and small single-use slacked disc filters in plastic housings are avail le and have the appearance of cartridge filters but consist of a series of separate membranes rather than of one continuous pleated membrane. This added complexity may make sterilization by saturated steam more difficult. Deep vacuums intended to ensure effective air removal from the filter media... 

The operational part of the cartridge is the membrane, pleated to provide a significantly large surface area in a compact presentation. A cartridge filter of 5 cm diameter and 25 cm length may contain up to about 6500 cm of pleated membrane surface [6]. Greater surface areas of membrane require lower applied differential pressures to achieve acceptable rates of volume flow through filters. The membrane is in most instances sandwiched between two support layers of a pleated protective nonwoven fabric (Fig. 3). This is mainly because membranes... 

Fig. 3 Construction of pleated membranes for cartridge filters. (Courtesy of the Pall Company, Glen Cove, New York.)...

---