In the production of edible oils from oil seeds and oil-rich fruits it is necessary to process the crude oil to separate pure oil (olein) from the crystalline solids (stearin), the amount of each depending on the temperature of the process. The growing importance of palm oil processing meant that the traditional rotary vacuum filter […]
Unlike the other horizontal belt filters, the (paper) band filter is a device used for clarifying machine tool and similar coolants and lubricants free of contaminants. It began as a means for holding a sheet of paper through which the oil/water emulsions could flow, and has developed into quite a sophisticated continuous filter. An automatic […]
Horizontal belt filters working on the vacuum principle were originally developed for process applications where intensive washing is required, but are now also employed for a wide variety of filtering requirements. They have become such a versatile processing tool that they have taken a considerable share of the market from the former workhorse of the […]
The capillary disc filter looks like any other standard rotary vacuum disc filter, as can be seen in Figure 3.25 , but the filter medium is a finely porous ceramic disc, which draws filtrate through the disc material by capillary action, under the applied vacuum. The filter discs are made of sintered alumina with uniform […]
Rotary disc vacuum filters have the advantage, compared with rotary drum filters, of giving a much larger filter area per unit of floor area. They are thus particularly suitable for the processing of bulk products, for example in coal preparation, ore dressing, pulp and paper processing, and so on. The principle of construction of a […]
The rotary pressure drum filter is basically a rotary drum filter enclosed in a large pressure shell, with suitable means for getting the feed suspension and any wash liquors in through this shell, and the filtrate and filter cake out of it. This results in a complex piece of machinery, as a glance at Figure […]
A range of filter media can be used on drum filters, depending on the specific application. Most media have a cut-off point below which value particles pass through the filter. One way to achieve high filtration efficiencies at low particle sizes is to coat the filter medium with a fine powder – the precoat – to […]
The choice of the most suitable method of cake discharge for a particular RVDF application depends not only on the nature of the cake, but also on considerations of protection of the main filter medium from wear. The cake can vary in consistency, thickness and structure according to the products being handled, from a pastelike […]
The rotary vacuum drum filters described so far utilize a filtrate flow from outside the drum to the inside, where the vacuum is applied. Rotary drum filters also exist with filtrate flow from inside the drum. A simple version is little more than a rotating drum strainer, used to clarify raw water, as filters for […]
A rotary vacuum drum filter consists of a cloth-covered compartmental drum suspended on an axial shaft over a feed trough containing the suspension, with approximately 50 to 80% of the screen area immersed in the suspension. The trough will usually include an agitator to maintain the feed suspension at a constant concentration. The oscillating swing-type […]
