Apron feeder

Belt or apron feeders can also be used to give uniform feed from a bin, but care must be taken that dead spots are not produced in the... 

FIG. 21-28 Sloping striker plate in the belt of an apron feeder ensures the flow of non-free-flowing solids, Couitesif of Chemical Engineering,)... 

Basically, they are heavy-duty feeders. Apron feeders are composed of a series of steel plates, which overlap to form a continuous belt (Figure 25). The plates are linked together or mounted on a conveyor chain and driven by sprockets. 

Apron feeders are mostly used to introduce solid waste in the processing plant. They can be installed either horizontally or with an upward inclination. 

Figure 25 Apron feeder. (With permission from Ref. 26.)...

The apron feeder capacity is estimated by this relationship ... 

S = perpendicular cross-section of solids on apron feeder(m )... 

Steel plate conveyors are similar to apron feeders, as described in details in Section 10.1. The main difference lies in the length of the conveyor, which in any case is longer than that of the feeder but usually no longer than 35 m, as it is a heavy construction and, consequently, the demands in installed power are increased with length. They are mostly used to convey mixed-waste material to the disposal site. 

Metso Minerals, World-Class Apron Feeders , Brochure No 1802-05-04-MPR, 2004, p. 1. 

The lead concentrates and fluxes are transported to the mixing room bins, as previously discussed. Under each mixing room bin, an apron feeder with a pre-set gate continually withdraws the material and discharges it onto a conveyor belt. Scale systems are used to... 

Screw feeder Rotary plough Belt feeder Apron feeder... 

Apron feeder < 18° incline 2-12 m horizontal 10-150 Mg/h not for particles that cake or are light and fluffy or are fine with < 150 pm diameter, pneumatic transportation limited by solids loading that plugs pipe. 

Use a vibratory, screw or apron feeder to unload the particles onto the conveyor. Prefer dense phase to dilute phase pneumatic conveying (H). 

Bin apron feeder for controlled conveyor loading linked to belt weigher for accurate control... 

The empty skip leaves the surface dump bin and descends to pick up another load of ore. The apron feeder commences loading the load-out conveyor with 60 tonnes of ore at a specific time after the skip has left the dump a time delay is incorporated in the system design to initiate this process. The load-out conveyor remains running at slow speed while accepting the ore from the feeder... 

The load-out conveyor resumes to slow speed while waiting for the time delay signal to receive a load from the apron feeder. 

The obvious drawback of this arrangement is the additional cost associated with the second conveyor, apron feeder, and subsequent larger excavation requirements. Depending upon the conveyor size, the drift width requirement can sometimes make this option nonviable due to ground stability issues. Additionally, there are associated costs with more frequent skip finer replacement at the impact zone on the skip back wall. 

The slewing conveyor loading arrangement, as illustrated in Figure 2, depicts a typical apron feeder at the bin bottom with a short discharge belt feeding a slewing conveyor. 

Feeders interface to the gravity flow of hoppers and silos, and promote and control the passage of materials onto conveyors and containers or into process equipment. There are very many types which have found application for different materials, material lump sizes, capacities, control requirements, and hopper or silo configuration. The most popular types include vibrating feeders, belt feeders, screw feeders, apron feeders, and rotary or star feeders. It is usually of critical importance to ensure that the type of feeder selected has a proven history of suitability for the application. 

A feeder is a device used to control the flow of bulk solids from a bin. Any feeder must be selected to suit a particular bulk solid and the range of feed rates required. It is particularly important to design the hopper and feeder as an integral unit, in order to ensure that the flow from the hopper is fully developed with uniform draw of material from the entire hopper outlet. There are several types of feeders but the most common are the belt or apron feeder, the screw feeder, the vibratory feeder, and the star feeder. Careful considerations, such as those described above, should be taken in selecting a feeder for a particular application. 

Types of feeders, (a) Apron feeder (b) screw feeder (c) vibratory feeder and (d) star feeder. 

Primary breaking is either by hammer mill or by spiked rolls in combination with a knife shredder. Batteries are handled by front end loader into a hopper with apron feeder discharging onto a conveyor and into the primary breaker. Breakage releases the dilute sulfuric add electrolyte and equipment must be constructed of stainless steel and be fully enclosed to contain add spray and fine particulates. If crushing rolls are used the discharged material is wet screened to separate fines and electrolyte, and the coarse material is passed under a magnet to remove any tramp steel and is then processed in the knife shredder. 

A limestone hopper at a cement plant was duplicated and uprated (the hopper slot was lengthened in an attempt to increase delivery rate). As Figure 16.6 shows, the hopper was wedge-shaped and fed by an apron feeder. The hopper fed from the rear of the feeder and required the feed material to be dragged... 

Figure 16.6 Initial design of limestone hopper with apron feeder. A high proportion of...

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