Filtration unit

Gas Filtration Vendors are the primary source for sizing baghouses, however the process engineer should at the very least make an estimate of the pressure drop requirements for an intended system. The pressure drop will, of course, provide information needed on the approximate size of the fan needed, and the energy requirements needed to operate a system. In fact, pressure drop is the primary parameter in establishing particle removal efficiency for a fabric filtration unit, and hence, is usually the starting place for discussions with the equipment supplier. 

Comparative calculations of specific capacities of different filters or their specific filter areas should be made as part of the evaluation. Such calculations may be performed on the basis of experimental data obtained without using basic filtration equations. In designing a new filtration unit after equipment selection, calculations should be made to determine the specific capacity or specific filtration area. Basic filtration equations may be used for this purpose, with preliminary experimental constants evaluated. These constants contain information on the specific cake resistance and the resistance of the filter medium. 

The first two categories, clarifying and crossflow filters, have been very well developed and optimized for use in biotechnology and standard wastewater treatment applications. Equipment is easily available for these applications, whether as small 0.2 micron sterilizing filter used to terminally sterilize 100 ml of product solution, or a small 500 ml crossflow filter used to concentrate a small amount of antibody solution. Many vendors of this equipment to wastewater treatment applications have their origins in the CPI (Chemical Process Industries), and have incorporated many of the scale-up and optimization properties developed in much larger units used in large scale chemical production. As a result, these two filtration unit operations are one of the most optimized and efficient used in wastewater treatment. 

The third category, cake filters, although well developed in many wastewater treatment applications, are the least developed of the filtration equipment use by the Biotech Industry. In the organic synthesis laboratory sometimes very simple equipment like a funnel and filter paper is used to accomplish this operation. Some other operations used for this filtration step in the lab are more sophisticated, but many are very labor intensive and limit the capacity of the overall production process itself. As a result, there is a need for optimization of the cake filtration equipment used in biotechnology. Cake filtration equipment is available in batch and continuous modes. Following are several examples of cake filtration units ... 

Figure 6. Cross section of a typical filtration unit.

Downstream side The side of a product stream that has already passed through a given filter system portion located after the filtration unit. 

Wastewater from the concentration and filtration units W,3 (300 ton/hr, 30 ppmw methanol). 

Filtration units can be incorporated into circulation lines, thus ensuring that clean oil is fed to gears and bearings. 

Commercially available plate- and frame- type ultrafiltration equipment are used for exopolysaccharide concentration. The membranes are polysulphone or polyvinylidine fluoride with molecular weight cut-off between 20-60,000. There is a relatively low eneigy requirement (1-2 kWh m 3) for pumping the fluid through the filtration unit at the desired pressure. Pressure difference across the membrane is of the order 2-14 atmospheres. 

A shake-flask broth was filtered with a filtration unit and all the process conditions and variables are defined in the following table. 

Flotation-Filtration Systems 6.9.3.1 Combined Flotation-Filtration Unit... 

A combined flotation-filtration unit, shown in Figure 6.8, is an advanced water clarification system, using a combination of chemical flocculation, DAF, and rapid sand filtration in one unit. The average processing time from start to finish is less than 15 min.15-57-58... 

The following paragraphs briefly describe how the flotation-filtration unit shown in Figure 6.8,... 

FIGURE 6.8 Top and side views of the flotation-filtration unit. (Taken from Krofta, M. and Wang, L.K., Flotation Engineering, Technical Manual Lenox/1-06-2000/368, Lenox Institute of Water Technology, Lenox, MA, 2000.)... 

The flotation-filtration unit can be either manually operated or completely automated with a level control [17] that operates the inlet flow valve [18]. Filter backwashing can also be automated by a timer or head loss control [19]. 

It is important to note that all flotation clarifiers63,64 may be used for treatment of nickel-chromium plating wastes regardless of their shapes (rectangular or circular) or manufacturers. A filtration unit is an optional step for final polishing. The treatment efficiency of separate flotation and filtration units65 will be similar to that of a combined flotation-filtration unit (Figure 6.8). 

The filtration system consists of a granular bed multimedia filter unit, a GAC filter unit, and/or a membrane filtration unit.10 12... 

A DAFF clarifier s top portion is similar to a DAF clarifier, but its bottom portion is an automatic backwash filtration unit. The readers are referred to elsewhere for a detailed description of a DAFF clarifier.41 43... 

Fig. 3.17 Anton Paar accessories for special applications gas loading system, filtration unit, UV lamp (left to right).

For general solid-phase reactions in a dedicated multimode instrument, an adaptable filtration unit is available from Anton Paar (see Fig. 3.18). This tool is connected to the appropriate reaction vessel by a simple screw cap and after turning over the vessel, the resin is filtered by applying a slight pressure of up to 5 bar. The resin can then be used for further reaction sequences or cleavage steps in the same reaction vessel without any material loss. However, at the time of writing, no applications of this system for solid-phase synthesis had been reported. 

Poly(diallydimethylammonium chloride) (PDDA) was purchased from Aldrich Chemical Co. 2-Morpholinoethanesulfonic acid (MES) was from Wako Pure Chemical Industries Ltd. Poly(butylviologen) (PBV), shown in Scheme 1, was synthesized according to literature method and checked by HNMR [7], Ultrapure water (18.3 M l) was prepared with a Milli-Q filtration unit of Millipore Corp. 

Using a HEPA air filtration unit (fitted with appropriate filters) to remove contaminants from the outside air before it is pulled into the building... 

Because a water filtration unit can be designed to fit most budgetary constraints, it is recommended that one of these units be installed in every home and building. Several companies that could be contacted for purchasing water filtration units are ... 

Sample Location Double filtration unit treating dairy waste (exclusively)... 

This sample is included because it is an interesting departure from the odorous emissions more commonly associated with water reclamation works. Aqueous dairy waste sampled at this time and subsequently analysed by the same techniques demonstrated that none ol the listed osmogenes were present. The odorous emission was thus a function of the filtration unit and its mode of operation rather than directly originating from the effluent being treated. The key osmogenes are believed to be -... 

Coverage of thermal, chemical, surface, and mechanical properties of inorganic membranes includes discussion of pore diameter, thickness, and membrane morphology. You ll gain valuable insights into membrane modification, as well as the design and operation of membrane filtration units. 

The use of in-line filters between injectors and colunm can prevent the accumulation of particulate material on the inlet frit of an analytical column, and can avoid back-pressure problems. A second, and often overlooked, site for filter installation is between the column and the detector. Cartridge-type filtration-units that contain readily changed, 0.2-/i,m filters are commercially available, and they contribute insignificantly to peak broadening. These filters are essential for the prevention of clogged detectors when laboratory-packed columns are used. 

Buffer filtration device (either a glass filtration unit, fitted with a 0.45-itm membrane, connected to a side-arm flask or a tissue culture sterilization filter unit). 

---