Filters vertical leaf

Horizontal Vessel, Vertical Leaf Filters. In a cylindrical vessel with a horizontal axis (Fig. 18), the vertical leaves can be arranged either laterally or longitudinally. The latter, less common, arrangement may be designed as the vertical vessel, vertical leaf filters but mounted horizontally. Its design is suitable for smaller duties and the leaves can be withdrawn individually through the opening end of the vessel. 

The OMD leaf filter (Stella Meta Filters) is a vertical leaf filter with a mbber diaphragm suspended between the leaves. The cake that forms on the leaves eventually reaches the diaphragm at which point pump pressure is used to inflate the diaphragm and compress the cake. The cake discharge is by vibration. 

Vertical Pressure Leaf Filters are essentially the same as Horizontal Plate Filters except for the orientation of the filter elements which are vertical rather than horizontal. They are applied for the polishing slurries with very lov solids content of 1-5% or for cake filtration with a solids concentration of 20-25%. As with the horizontal plate filter the vertical leaf filters are also well suited for handling flammable, toxic and corrosive materials since they are autoclaved and designed for hazardous environments when high pressure and safe operation are required. Likewise, they may be readily jacketed for applications whenever hot or cold temperatures are to be preserved.The largest leaf filters in horizontal vessels have a filtration area of 300 m and vertical vessels 100 m both designed for an operating pressure of 6 bar. 

Select a Vertical Leaf Filter for an application when... 

Horizontal leaf filters OMD leaf filter Vertical leaf filters Leakage, in FETs, 22 253, 254 Leakage prevention, pumps for, 21 76 Leak detection and repair (LDAR) program, 10 70, 71-75 14 205 Leakers, 10 70, 72 Leak frequency, 10 72... 

Pressure leaf filters are supplied in a wide range of size and materials of construction. One typical design is the Verti-jet unit with a vertical tank and vertical leaf filter, as shown in Figure 7.12, with rectangular leaves mounted individually but connected to a common outlet manifold. For sluice cleaning either a stationary or oscillating jet system... 

For more efficient leaf cleaning, horizontal tank-vertical leaf filters are made with various types of movable sluices. 

In Figure 22.24, resistance plots for p/ q versus are shown for a series of runs involving Kentucky No. 9 liquefied coal filter in the U.S. Filter Co. vertical leaf filter. They follow the general trends of filtrations subject to both medium and cake clogging as illustrated in Figure 22.23. 

In comparison with nutsche filters, leaf filters provide more filtration area in the same volume of a pressure vessel. They are more suitable for handling larger quantities of slurry. Leaf filters can be subdivided into four classes in accord with the vertical or horizontal position of the tanks and leaves. In Figures 22.32 and 22.33, vertical leaves are shown in vertical and horizontal tanks. For vertical leaf filters, to prevent cake dropping, the cake thickness is normally restricted to 3.5 to 4.0... 

FIGURE 22.32 Vertical tank vertical leaf filter. 

FIGURE 22.33 Horizontal-vessel, vertical-leaf filter. 

FIGURE 58.4 Vertical tank, vertical leaf filter. (From Shirato, M. et al.. Filtration—Principles and Practice, eds. M.J. Matteson and C. Orr, Marcel Dekker, New York, pp. 299-423, 1987. With permission.)... 

Kgure 11.48 Vertical leaf filters back-flushing and sluicing discharge (Courtesy of U.S. Filter Co., Vanpipe Co. Ltd, Burslem, Stoke, U.K.)... 

In these units, only half the available leaf area is available for filtration. Also, the horizontal units are limited to sizes up to 65 m so that, despite the inherent cake loss problem, vertical leaf filters are usually ecified for larger tonnages. 

Monel and lined carbon steel are standard materials of construction for filter vessels. Linings are similar to those used in primary filters. Figure 7.60 shows a typical vertical-tank vertical-leaf filter. The stream to be filtered enters the body of the tank. A bottom connection is shown, but there are other options. The leaves are arranged vertically, and flow is from the outside to the inside of the leaves. Filtrate collects in a pipe at the bottom this also serves as support for the filter elements. The tank also has drain, vent, and compressed air connections. The detail shows one type of assembly that can simply be lifted from the effluent pipe. O-rings supply the seals. 

Pressure-vessel leaf filters (a) vertical-tank, vertical-leaf filter, and (b) horizontal-leaf filter. 

One operational problem with these filters is concerned with the disposal of the heel of unfiltered slurry which is still in the vessel at the end of the filtration period. This is particularly troublesome with the vertical-leaf filters because compressed air cannot be used to complete the filtration of this heel... 

Vertical-tank, vertical-leaf filters (Figure 12.6)... 

In general, the horizontal-vessel, vertical-leaf filters with the leaves arranged laterally can be designed up to filtration areas of 300 m. Cake washing is possible but it must be carried out with caution because there is a danger of the cake falling off. 

Industrial filtration units can be either batch or continuous in operation. In addition to the plate and frame filter press of Figure 14-1, there are leaf filters that also function in the batch mode. Figure 14-5 shows both a vertical leaf filter and the filter leaf itself. Other leaf filters include a Niagara type (Figure 14-6), which uses a horizontal leaf filter, and the Sweetland type (Figure 14-7), which consists of two half-cylinders that allow the bottom half to be opened downward to access vertical disk-shaped leaves. 

Figure 14-5. Vertical leaf filter and filter leaf. (Courtesy of Industrial Filter and Pump Mfg. Co.)...

Horizontal body with vertical leaf filter, i.e., Sweetland, Vallez, Auto-Filters, and Industrial. 

Vertical tank with vertical leaf filters i.e., Niagara, Angola, and Pronto. 

There is a large variety of conventional filtration equipment. One of the most common types of batch filter is the plate-and-frame filter (Figure 12.4). This filter consists of a number of filter chambers with medium-covered filter plates alternated with frames that provide space for the cake. The chambers are closed and tightened by a hydraulic ram or screw which pushes the plate and frame together. Other types of batch filters are horizontal or vertical leaf filter, tray filter, tube or candle filter, and Nutsche filter. These are all enclosed pressure filters. 

---