One of the most common sights in a power station or processing plant is the large chamber filled with an array of filter bags, known in some industries as a baghouse, and in others as a fabric filter. These are used on large exhaust gas streams, mainly to prevent pollution from dust residues, but quite […]
Filter bags for liquids are effective in removing particulate contaminants in the processing of a wide variety of materials. Bag filtration is a pressure-driven operation, wherein the product to be filtered is forced through the filter unit. Such a unit would normally consist of the filter housing, a retaining basket and the filter bag. Generally […]
In the dry filtration processes that use pads or panels to capture dust, the filter surface is basically flat – one side of the filter sheet in a pad filter, or the upstream surface of a pleated medium panel. The group of filter types to be described next capture the dust inside or on the […]
The flat elements employing a thick filter medium and working by depth filtration, are distinguished here, as filter pads, from those using thin sheet media and working by surface filtration, which are called filter panels. The basic need of all kinds of filter is to maximize the available filtration area, and a single thin sheet […]
The pad filter (often called a cassette) is a special case of the range of panel filters, all of which are made in standard sizes, to fit air-conditioning installations. The pad, as its name implies, is a thick flat sheet of fibrous filter medium, made either by wet-laying (as in paper) or by dry-laying (as […]
The requirements for dust filtration vary considerably with the particle size of the dust material, and with its concentration in the suspending air or gas (and also with the velocity of the suspending gas). Where the concentration of the solids is reasonably high, the most likely separator would be a cyclone, or even a simple […]
From the complexities of the centrifugal filter, the Handbook moves on to one of the simplest forms of filter, used mainly for dust removal from air, in ventilating situations. These are the pad or panel filters, consisting of thick sheets of filter medium, or thinner materials folded to occupy the same space as a pad, […]
The moving bed centrifuge with a cylindrical basket is known as the pusher centrifuge, and is one of the most common types of centrifuge for separating fast-draining crystalline or fibrous solids from suspension, at high throughput rates of solids. In its basic action, a layer of filter cake forms on the inside of the basket, […]
There are two main designs of moving bed centrifuge: those with a cone-shaped basket and those with a cylindrical basket. In the latter, solid movement needs mechanical assistance, but in the conical basket, the solids are potentially free to slide from the narrow end of the cone, which is where the feed zone is, to […]
In the fixed bed centrifuges just described, the separated solids form a cake in the basket that is stationary with respect to the basket while filtration is occurring, and the solids then have to be dug out of the basket in some way. In the moving bed centrifuges, on the other hand, the separating cake […]
