Bucket elevators capacity

Fig. 6. Bucket elevators (a) centrifugal (b) continuous (c) positive (d) internal discharge (e) super capacity and (f) cement mill.

Industrial, centrifugal elevators usually operate at speeds of about 75 m /min, and handle free-flowing, fine and loose materials having lump sizes of <50 mm. Sticky material can be a problem. Fine fluidizing materials often require perforations in the bottom of the buckets to vent entrapped air. Centrifugal elevator capacities range up to 370 m /h for a single row of buckets, and up to 1400 m /h for multiple rows of buckets. The buckets can be mounted on a belt or chain. 

Bucket elevators are the simplest and most dependable units for making vertical lifts. They are available in a wide range of capacities and may operate entirely in the open or be totally enclosed. TFe trend is toward highly standardized units, but for special materials and high capacities it is wise to use specially engineered equipment. Main variations in quality are in casing thickness, bucket thickness, belt or chain quahty, and drive equipment. 

Bulk alum can be stored in mild steel or concrete bins with dust collector vents located in, above, or adjacent to the equipment room. Recommended storage capacity is about 30 days. Dry alum in bulk form can be transferred or metered by means of screw conveyors, pneumatic conveyors, or bucket elevators made of mild steel. Pneumatic conveyor elbows should have a reinforced backing as the alum can contain abrasive impurities. 

Bucket elevators are suited to vertical transport of sticky and abrasive materials. With buckets 20 x 20 in. capacity can reach 1000 cuft/hr at a speed of 100 ft/min, but speeds to 300 ft/min are used. 

TABLE 5.6. Capacities and Power Requirements of Bucket Elevator Conveyors... 

The carrying (elevating) capacity of bucket elevators depends upon the size of buckets, their spacing, speed of elevator and weight of material handled. When... 

The capacity of bucket elevators is calculated from this relationship ... 

The first 500 bpd semi-commercial bucket elevator Thermofor Catalytic Cracker went on-line at the Paulsboro refinery in 1941 with the first 10,000 bpd TCC unit being built by the Magnolia Oil Company at its Beaumont, Texas refinery in 1943. By the end of World War II, TCC capacity was at nearly 300,000 bpd. 

Bucket elevators (a) centrifugal-discharge-spaced buckets, (b) positive-discharge-spaced buckets, (c) continuous bucket, and (d) super capacity continuous bucket. 

A measure of 200 ton/h of limestone is to be transported to a processing plant 4 m above its storing place. Two options need to be contemplated to move the material a belt conveyor or a bucket elevator. The maximum slope for the belt conveyor is said to be 15°, its moving parts weight 1550 kg, and at maximum capacity the velocity is 24 m/min. For the belt conveyor, minimum values of the constants F and Lq apply. Demonstrate which conveying system would suit best for the duty of transporting the limestone. 

Fig. 5a Round-link chain for high-capacity bucket elevators (special style of construction)...

Table 12a Capacity data for vertical bucket elevators... 

A prestressed concrete silo of about 50 0001 capacity is illustrated in Fig. 2. Clinker is fed into it by two low-speed bucket elevators and is discharged through four bottom outlets. 

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