Feeder, arrangements

Another seal provided to enclose the nip is the feeder base at the end of the feeder arrangement which prevents material from escaping over the top of the... 

Other designs apply vacuum deaeration in a screw feeder or in the hopper of a force feeder arrangement to improve the effect of standard feeders. Similar results can be obtained with equipment called Vacu-Press it consists of two counter-rotating rolls of which one is hollow, perforated, covered with filter cloth, and evacuated. Material is slightly densified in the nip and deaerated under the influence of vacuum. 

Handling arrangements for bagged hydrate are usually quite basic, involving manual loading into a hopper with a screw or vibrating feeder arrangement to transfer the hydrate into the process. 

Dual-feeder arrangement. By incorporating two separate feeders, one for regrind and one for color concentrate, a more precise control of proportions can be achieved. 

Note When using either the single- or dual-feeder arrangements described here, it is advisable to mount the riser section on all processing machines so that the feeder units can be relocated if necessary. 

For applications that demand a very high level of purity, separators are available with two or three rare earth magnetic rolls, belts and feeders arranged in a cascading fashion. This enables antomated separation the particles with varying levels of paramagnetic susceptibility. 

FIG. 21-1 Typical feed arrangements for screw conveyors, a) Plain spouts of chutes, (h) Rotary cutoff valve, (c) Rotary-vane feeder, (d) Bin gate, (e) Side inlet gate. (FMC Corporation, Matetial Handling Systems Division. )... 

In a fixed construction, all the feeders in the switchboard, feeding the various load points, are securely mounted in the assembly and rigidly connected to the main bus. In the event of a fault in one feeder on the bus side, a shutdown of the entire switchboard may be required. A process industry or critical loads can ill afford such an arrangement. However, since this is the most cost-effective switchboard, it is also the most common type and is used extensively. It also suits all applications, except a process industry or critical loads, which may not be able to afford a total shutdown or prolonged downtime in the event of a fault. In such cases a draw-out type switchboard will prove to be a better choice as discussed below. A fixed-type construction may further be classified as follows. 

Padlocking arrangements may be required to lock the feeder in the OFF position when the machine is undergoing a shutdown or repairs. 

Typically, chemical formulations were supplied as balls or briquets and dispensed through bypass feeders or hanging baskets. Alternatively, pulverized or powdered treatments were dissolved in water and pumped to FW tanks or added via drip-feed arrangements. 

Figure 7. Conventional blow tank feeders (a) bottom-discharge arrangement (b) top-discharge arrangement.

Fig. 2 Swiss-roll -cell, arrangement of the electrodes 1 Steel net cathode 2,4 Polypropylene net as insulating separator 3 Nickel net anode 5 Current feeder...

Figure 5.3. Basic equipment arrangements of pneumatic conveying systems, (a) Vacuum system with several sources and one destination, multiple pickup (b) pressure system with rotary valve feeder, one source and several destinations, multiple discharge (c) pressure system with Venturi feed for friable materials (d) pull-push system in which the fan both picks up the solids and delivers them [after F. J. Gerchow, Chem. Eng. [17 Feb. 1975, p. )].

A unique modification shown in the pelletizer in Fig. 3.16 should also be noted. This unit incorporates an integral screw feeder discharging into the centre rear of the deep pan under the charge which is already in process. This arrangement eliminates free-fall of dry fine feeds, thus preventing dusting, and improves physical and visual access to the front of the unit. Reduced space and power requirements are also claimed for this design. 

A variety of feeding arrangements may be employed to ensure that particulate matter of appropriate bulk density is presented to the nip of the rolls. For smoothly flowing materials gravity feed may be used with a control device to adjust feed rate (Fig. 5.4). For fine powders which tend to bridge or stick and are of low bulk density, some form of forced feed (such as the tapered screw feeder shown in Fig. 5.5) must be used to de-aerate, pre-corn-... 

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