Hopper types

Chlorine is stored and transported as a Hquefied gas in cylinders of 45.4-kg or 68-kg capacity that are under pressure and equipped with fusible-plug rehef devices. Quantities in the range of 15 to 90 t are transported in tank cars having special angle valves on the manhole cover on top of the vessel. Tank barges of the open-hopper type having several cylindrical uninsulated pressure vessels are used for amounts ranging from 600 to 1200 t. Road tankers are used for capacities of 15 to 20 t. 

Top-feed drum filters are used for the treatment of very fast settling solids that cannot easily be kept in suspension. A drum filter may be preferable, rather than a horizontal pan or similar filter, because of its low cost, simplicity and reliability, and because of the relative ease with which it can be fitted with appropriate accessory features. A top feed drum filter incorporates multi-compartments, drainlines and a rotary valve identical to those in a conventional drum filter. The feed slurry is introduced at, or just before, top dead centre, and the cake is discharged from 90° to 180° from the feed point. The feed slurry can be distributed across the drum by sprays or a weir box, or it may be contained within a 3-sided head-box which is sealed against the moving drum at each end and across the back on the ascending filter surface. For materials which do not cake together sufficiently to be self-supporting on the drum surface, a hopper-type top feed filter may... 

Wagons fitted with (i) grease lubricated axle boxes (ii) end falling doors and (iii) doors on the floor (hopper type) should not be used for the conveyance of military explosives. 

The principle of the moving bed of Fig. 3.37a in cross-flow to the air supply is used for roasting zinc blende and for the combustion of large coal on chain grate stokers. Another kind of moving bed is found in hopper-type reactors in which particles are fed at the top and continuously move downwards to be discharged at... 

Figure 8.1. Hopper types based on flow patterns (a) Mass flow hopper, (b) Core (funnel) flow hopper.

Hazardous substances, as defined in 49 CFR 171.8, transported in cargo tanks, portable tanks, or hopper-type vehicles with capacities in excess of 3,500 water gallons, or in bulk explosives Division 1,1,... 

H(9) Factor to account for variation in arch thickness, hopper angle, and hopper type... 

Road tankers and ISO containers have a chlorine capacity of 15-201. The design of and the equipment on chlorine pressure road tankers is similar to these of rail tankers. In North America, large amounts of chlorine are transported by tank barges [24], These barges usually are of the open-hopper type with several cylindrical uninsulated pressure vessels. The total capacity of barges ranges from 600 to 12001. The chlorine is transported at low temperature. 

Comparison with Mechanical Blenders or Homogenizers. Mechanical blenders normally have recirculation systems either within the blender or placed outside it. There are several types, but they have in common steep hopper half-angles with respect to vertical as compared to fluid bed blenders. This is required to allow all the mixed material to flow out of the blender. The silo geometry has to ensure mass flow conditions, which accounts for even withdraw of products, but at the same time, the angles have to be somewhat shallower to allow shear between the flowing layers of products to cause blending. If the outer hoppers are shallower, then normally, blenders are equipped with inserts, such as hopper-in-hopper types. These inserts can work in both axisymmetric and plane flow blenders, although the former types are more common. 

SpiralTlevator Materials are moved upward by the centrally located spiral-type conveyor in a cylindrical or cone-shaped Nautamix vessel (Fig. 37c and d). Blending occurs by the downward movement at the outer walls of the vessel. The vessel serves the dual purposes of blending and storage. In these mixers the screw impeller actively agitates only a small portion of the mixture and natural circulation is used to ensure all the mixture passes through the impeller zone. In the case of Nautamix, an Archimedian screw lifts powder from the base of a conical hopper while progressing around the hopper wall. 

Tablet Press. The main components of a tablet compression machine (press) are the dies, which hold a measured volume of material to be compressed (granulation), the upper punches which exert pressure on the down stroke, and the lower punches which move upward after compaction to eject the tablets from the dies. Mechanical components deflver the necessary pressure. The granulation is fed from a hopper with a feed-frame on rotary-type presses and a feeding shoe on single-punch presses. A smooth and even flow ensures good weight and compression uniformity. Using the proper formulation, demixing in the hopper is minimized.

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