Depth filter cartridges

Hou, K.C. Zaniewski, R. Depyrogenation by endotoxin removal with positively charged depth filter cartridge. J. Parenter. Sci. Technol. 1990, 44, 204-209. 

The pre-treated water flows to the cartridge filter (nominal pore size of 5.0 tm) at 70 m /h. The pressure drop (AP) across the filter is monitored by a local AP indicator/ switch. When AP exceeds 1 bar or every 3 months, the plumed cartridges are replaced. The pleated depth filter cartridges are sized based on flow rate and pressure drop, e.g. the rating is 301/m per 25 cm long cartridge with a pore size of 5.0 pm. 

A novel water pmification filter has been in development over the past seven years. The first version is a pleated depth filter cartridge that has high particle retention efficiency at moderate to high flowrates, while also having a high particle retention capacity. The filter media is also sold as non-woven media by Ahlstrom imder the tradename Disrupter . Argonide manufactures the filter cartridge from Disraptor media. 

Depth-type cartridges, for cartridge filters, 11 368-369 DEREK, 6 19... 

Aerobic fermentation processes also require a continuous supply of large quantities of air, typically on the order of one volume of air per volume of liquid per minute, VVM. Sterilization of this air is mandatory in almost all fermentations. Absolute filter cartridges of polymeric membranes are now used almost exclusively in the fermentation industry. Relatively small units have replaced the large depth filters used in the past. Still, water and particulates pose a major problem for filters thus requiring the use of prefilters and traps to remove these contaminants before they reach the absolute filter. Parallel installation of the filters prevents a total shutdown of the fermentation process in the event of filter clogging. 

There are many filter configurations within the industry, such as sheet or modular depth filter types for prefiltration purposes, flat filter membranes mainly for microbial detection and, specifications, and, most commonly, filter cartridges containing either depth filter fleeces or membrane filters. Such membrane filters are available in a large variety of membrane polymers for different applications. These materials are discussed later in the chapter. 

In smaller water purification systems, we can often find a cartridge-type depth filter used for the particle removal. The cartridge is made of cellulose, cotton, or polymer fibers, which trap dirt particles throughout its volume. Once a cartridge reaches its holding capacity, it is disposed of and replaced by a new one. 

The disc has a depth-filter region from 100 to 200 pm, followed by the major extraction region that is 800 to 900 pm in thickness. Thus, the disc is both filter and sorbent. Several advantages of the disc over standard SPE cartridges include ease of processing cloudy samples (important in automated procedures where plugging may cause serious losses of samples), fast processing times, and much decreased volumes of solvent (Blevins and Schultheis, 1994). 

Clarification of liquids often calls for the use of depth filtration equqnnent. The process techniques used and the filtration mechanisms involved in depth filters are outlined in Ch t 6, which includes information on sand filters and cartridges. 

Depth Filters. All the mechanisms for particle collection provided in Section 6.1, except surfece straining, are relevant in cartridge depth filtration. Metal fibers are preferred to... 

Filtration processes may be classified as either depth filtration or surface filtration. Depth filtration relies on a layer of porous media in which suspended particles in the beer are trapped within the media. Examples in brewing include filter aid filtration, sheet filtration and some forms of filter cartridge. Surface filtration normally refers to membrane technology. A thin layer of membrane has pores throughout the structure. This means that it is possible to achieve very exact filtration, perhaps enabling sterilisation, but typically the quantity of suspended beer particles that may be removed is less than for depth filtration. 

At the time of writing the most important technique to achieve sterile filtration in a brewery is through the use of cartridge filters. These comprise a membrane or depth filter that is a relatively thin layer and is pleated within the snpport stmctnre to provide a high filtration area in a compact volume (Figure 11.3). 

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