Floor space

Rotary Vacuum Disk Filters. An alternative to the dmm filter is the disk filter, which uses a number of disks mounted vertically on a horizontal shaft and suspended in a slurry reservoir. This arrangement provides a greater surface area for a given floor space, by as much as a factor of 4, but cake washing is more difficult and cloth washing virtually impossible. 

The vertical recessed plate automatic press is shown schematically in Figure 15. Unlike the conventional filter press with plates hanging down and linked in a horizontal direction, this filter press has the plates in a horizontal plane placed one upon another. This design offers semicontinuous operation, saving in floor space, and easy cleaning of the cloth, but it allows only the lower face of each chamber to be used for filtration. 

The primaiy advantages of a centrifugal pump are simplicity, low first cost, uniform (nonpulsating) flow, smaU floor space, low maintenance expense, quiet operation, and adaptability for use with a motor or a turbine drive. 

Car-bottom furnaces differ from standard types in that the charge is placed upon movable cars for running into the furnace enclosure. The top oi the car is refractory-lined and forms the furnace hearth. The top only is exposed to heat, the lower metal structure being pro-tec ted by the hearth brick, sand, and water seals at the sides and ends and by the circulation of cooling air around the car structure below the hearth. For use where floor space is hmited elevator furnaces serve similar purposes. 

Working capacity, nd Total volume, nd Heating surface, ni Drive, kW Floor space, ni Weight, kg Purchase cost (1995) ... 

Size numher Capacity, U.S. gal Typical supplied horsepower Floor space, ft... 

This type of clarifier is used in apphcations such as prehminaiy oil-water separations in refineries and clarification of waste streams in steel mills. When multiple units are employed, common walls are possible, reducing construction costs and saving on floor space. Overflow clarities, however, generally are not as good as with circiilar clarifiers, due primarily to reduced overflow weir length for eqmvalent areas. 

The filter press has the advantage of simplicity, low capital cost, flexibility, and ability to operate at high pressure in either a cake-filter or a clarifying-filter application. Floor-space and headroom needs per unit of filter area are small, and capacity can be adjusted by adding or removing plates and frames. Filter presses are cleaned easily, and the filter medium is easily replaced. With proper operation a denser, drier cake compared with that of most other filters is obtained. 

Of all continuous filters, the vacuum disk is the lowest in cost per unit area of filter when mild steel, cast iron, or similar materials of construction may be used. It provides a large filtering area with minimum floor space, and it is used most in high-tonnage dewatering apphcations in sizes up to about 300 m" (3300 ft") of filter area. 

Relatively expensive, but high capacity for a given floor space used for finer separations. 

The Humphreys spiral concentrator is a spirally shaped channel or launder with a modified semicircular cross section, as illustrated in Fig. 19-30. The standard spiral consists of five complete turns, but three-turn units are used in some instances when an unusually rapid and clean separation takes place, as in second-stage or cleaner spirals. There is a drop of 0.34 m (13.5 in)/turn as the flowing pulp progresses from the top to the bottom of the spiral. One spiral concentrator occupies about 0.37 m" (4 ft") of floor space and about 2.1 m (7 ft) of headroom measured from feed to discharge box. The optimum particle-size range of feed particles for spirals is about 10 to 200 mesh (2 to 0.074 mm). 

Slide Conveyors Simple gravity slides and spiral chutes, while not technically conveyors, are widelv used with conveyor systems or as separate units for lowering materials from one floor to another. They are low in cost and require httle floor space if slopes are held at fairly steep angles. However, they must be used only after a careful study... 

Aisle racks, used when there is a rapid turnover of inventory, permit a storage depth of only one or two pallet loads but offer the advantage of instant access to the stored item. Although this requires only a minimum of lift-truck time to store or retrieve a pallet, a high percentage of floor space must be devoted to aisles. 

The combination of diafiltration and batch concentration can be used to fractionate two macrosolutes whose retentions differ by as little as 0.2. It is possible in principle to achieve separations that are competitive with chromatography. When tanks and other equipment are considered, as well as the floor space they occupy, the economics of membrane separation of proteins may be attractive [R. van Reis, U.S. Patent 5,256,294 (1993)]. 

This test is intended to determine the temperature rise in different parts of the motor windings while running at rated conditions and the permissible temperature rise limits are specified in Table 11.1. While preparing for the temperature rise test the motor should be shielded from currents of air coming from adjacent pulleys, belts and other components to avoid inaccurate results. Sufficient floor space should be left between the machines... 

When minimum floor space for large filtration areas is required. 

Figure 9 shows the details of a typical horizontal tube-type ozone generator. This unit is preferred for larger systems. Water-cooled plate units are often used in smaller operations. However, these require considerably more floor space per unit of output than the tube-type units. The air-cooled Lowther plate type is a relatively new design. It has the potential for simplifying the use of ozone-generating equipment. However, it has had only limited operating experience in water treatment facilities. 

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