Horizontal belt filters

Agitated/Monoplate Nutsche Filter/Dryer Horizontal Plate Filter/Dryer Continuous Equipment Rotary Drum Filter Centrifugal Filter Horizontal Belt Filter... 

Vacuum filters include the nulschc filter, enclosed agitated vacuum fillers, the vacuum leaf filter, the tipping pan filter, horizontal rotating pan filters, horizontal belt vacuum fillers, rotary vacuum drum lilters. and rotary vacuum disk filters. 

Table or Pan Filter Rotary Drum or Disc Filter Horizontal Belt... 

Horizontal filter surfaces also allow a high degree of control over cake formation. Allowances can be made for changed feeds and/or different cake quality requirements. This is particularly tme of the horizontal belt vacuum filters. With these units the relative proportions of the belt allocated to filtration, washing, drying, etc, as well as the belt speed and vacuum quality, can be easily altered to suit process changes. 

Fig. 11. Schematic diagram of a horizontal belt vacuum filter.

Horizontal belt filters are well suited to either fast or slowly draining soHds, especially where washing requirements are critical. Multistage countercurrent washing can be effectively carried out due to the sharp separation of filtrates available. Horizontal belt vacuum filters are classified according to the method employed to support the filter medium. 

Another type of horizontal belt vacuum filter uses reciprocating vacuum trays mounted under a continuously traveling filter cloth. The trays move forward with the cloth as long as the vacuum is appHed and return quickly to their original position after the vacuum is released. This overcomes the problem of friction between the belt and the trays because there is no relative movement between them while the vacuum is being appHed. The mechanics of this filter are rather complex, and the equipment is expensive and requires intensive maintenance. A range of solvents can be used. Widths up to 2 m and areas up to 75 m are available. The cloth can be washed on both sides. 

Some horizontal belt vacuum filter designs incorporate a final compression stage for maximum mechanical dewatering. This is achieved by another compression belt which presses down on the cake formed in the preceding conventional filtration stage. 

Horizontal or vertical vessel filters, especially those with vertical rotating elements, have undergone rapid development with the aim of making truly continuous pressure filters, particularly but not exclusively for the filtration of fine coal. There are basically three categories of continuous pressure filters available, ie, disk filters, dmm filters, and belt filters including both hydrauHc and compression varieties. 

A horizontal belt filter has been used in place of the small dmm filter in filtration studies (17). The entire filter was placed in a large pressure vessel with no moving parts passing through the filter shell. There is no commercial filter based on this principle the utilization of the space inside the pressure vessel would be poor and the filtration areas limited. 

The vertical recessed plate automatic press, shown schematically in Figure 15 and described previously, is another example of a horizontal belt pressure filter. Cycle times ate short, typically between 10 and 30 minutes, and the operation is fully automated. The maximum cake thickness is about 35 mm washing and dewatering (by air displacement) of cakes is possible. Apphcations include treatment of mineral slurries, sugar, sewage sludge, and fillers like talc, clay, and whiting. 

The endless-belt percolator (Wakeman, loc. cit.) is similar in principle, but the successive feed, solvent spray, drainage, and dumping stations are hnearly rather than circulany disposed. Examples are the de Smet belt extractor (uncompartmented) and the Lurgi frame belt (compartmented), the latter being a kind of linear equivalent of the Rotocel. Horizontal-belt vacuum filters, which resemble endless-belt extractors, are sometimes used for leaching. 

On a horizontal belt filter, the equivalent sections extend across the filter in narrow strips. Therefore, changes in vacuum do occur rapidly and may be considered as happening at a particular point along the length of the filter. 

The examples which follow show how data from the correlations justpresented and a knowledge of thephysical characteristics of a particular filter are used to determine a filtration cycle and, subsequently, the size of the filter itself. The three examples which follow involve a disk, a drum belt, and a horizontal belt filter. 

Horizontal Belt Filter Since the total cycle of a horizontal belt filter occurs on a single, long horizontal surface, there is no restriction with respect to the relative portions of the cycle. Otherwise, scale-up procedures are similar. 

Additional equipment is sometimes integrated vvkth horizontal-belt filters to further devv ater the cake through expression. The addition of such equipment shouldn t be confused with expression equipment that utilizes filter medium belts. Belt type expression equipment is described later in the Expression subsection. 

Intensive soluble recovery or removal of contaminants from the cake as accomplished by countercurrent washing operations. This is especially the case with horizontal belt, tilting pan and table filters, which are described later in this subseetion,... 

When a large filtration area is required but a horizontal belt filter does not fit into the layout. 

Horizontal belt pressure filters, 11 379 Horizontal belt vacuum filter, 11 354-355 Horizontal box heaters, 19 511 Horizontal current classifiers, 16 619 Horizontal Feret s Diameter (HFD), 16 147 Horizontal injection wells, 16 613 Horizontal leaf filters, 11 366-367 Horizontal magnetic field-type (HMC), 23 857... 

Pressure filters, 76 658-659 horizontal belt, 77 379 thickening, 77 382-388 Pressure gauge, 20 645 Pressure gradients, flow caused by, 9 110 Pressure infiltration, of metal-matrix composites, 76 167-169 Pressure injection, moldings, 10 11 Pressure-jump method, 73 427-428... 

Reciprocating vacuum trays, with horizontal belt filters, 77 355 Reciprocity... 

The applications of horizontal belt filters are discussed by Blendulf and Bond 30. A typical filter for dewatering concentrates is shown in Figure 7.16, and it may be noted that this type of equipment is the most expensive per unit area. 

Figure 7.16. Delkor horizontal belt filter dewatering copper flotation concentrate (filter area 21 m2)...

Horizontal Belt Vacuum Filter The final piece of equipment is the horizontal belt filter, in which the nnderflow from the hydroseparator (basically gypsum diluted with process liquor) will be filtered to produce marketable gypsum of -12% moisture. The filter cake will be washed to reduce the amount of dissolved solids and will be conveyed to a prodnct gypsnm storage area. Filtrate from this filter will be disposed of as an aqneons pnrge stream. 

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