Grizzly Feeders

BASIC DATA YOU WILL NEED :
Nature of material being fed, its weight per cubic foot (kg/m.cu) and angle of repose. An approximate breakdown of material sizes. The greatest dimension of the largest piece. Required feeder conveying distance. Desired feeder capacity.

STEP 1 : Using the estimated percentage of large size (see * below) material, select the proper feeder width factor from Table A. Multiply this factor by the greatest dimension of the largest piece of material to determine minimum feeder width. Table A also shows throat opening factors when a four-sided hopper is utilized. Select the proper factor and multiply it by the same greatest dimension to find minimum hopper throat opening .


STEP 2
: Refer to Table C and identify the various combinations of feeder widths and slopes available for the desired capacity. Disregard any that are smaller in width than the minimum feeder width calculated in Step 1. It may become necessary to increase the minimum feeder width to obtain desired capacity. If so, disregard minimum width from Step 1 and substitute with the revised minimum feeder width for the desired capacity as shown in Table C.

STEP 3 : Now consider feeder length. Usually the size and positioning of companion equipment such as crushers, conveyors, aprons, hoppers, chutes, etc. suggest the given to minimum feeder pan length. The pan can also be no shorter than that which is needed to retain the material at its angle of repose on the pan after the feeder has been shut down.Determine minimum pan length by referring to Sketch B. Make your own scaled diagram to show slope of feeder and the angle of repose of the material on the pan at rest. Allow for the proper hopper throat opening (from Step 1) when using a four-sided hopper. Add 12" (30 cm) to the pan length as a safety factor to prevent the material from continuing to flow freely. Then add the length of any required grizzly sections to the minimum pan length to determine the minimum feeder length.

STEP 4 : Again evaluate width, slopes and capacities shown in Table C. Consider feeder length and headroom requirements. Match these with location, elevations and critical dimensions of companion equipment. Remember to allow for future capacity increase demands. Now select the width/slope combination that meets desired capacity and which is best suited to your particular application and installation peculiarities. You may want to go narrower and steeper to match up with a crusher opening; perhaps wider to accept feed from an existing apron conveyor. Or, you may have to go wider with less slope to accommodate elevation limitations. You are likely to discover that although more than one size feeder will satisfy your capacity requirements, one particular width/slope/length combination best serves your specific needs.

TABLE A - SECTION FACTORS

Percent Large Size*
Feeder with Factor
Hopper throat Factor
1-10%
1.3
1.5
10-40%
1.5
2
40-60%
2
2.5
60-90%
2.5
3
90-100%
3
3.5

* Those pieces which range in size from 75-100% of the largest piece. If the largest piece is 36" (91cm) then "largesize" are all pieces 27" (69 cm) and larger.

Primary grizzly feeders, VGF Series Straight-line motion. For controlled feeding of primary crushers after separation of quarry fines

Primary vibrating feeders VGC Series combine scalping of run-of-quarry and feeding oversize retained by grizzly bars to crusher. Fines passing the steel bars spacing like the crusher jaw setting, can be directly conveyed to screening.

Advantages :

Crusher operates at max. capacity with low wearing since the crushing chamber is not filled with undersize material.

Grizzly fines, discharged by crushed prod, belt conveyor, protect the rubber belt from attrition and shearing due to product discharge from primary crusher.

 

TABLE C - CAPACITIES       Based on material weighing 100 Ib./ft.cu (1600 kg/m.cu.), 12" (30 cm) material bed depth and 1/2" (13 mm) stroke                                            @ 800 RPM

Slope of Pan

FEEDER WIDTH IN MM/TONS PER HOUSE

800
900
1100
1200
1400
1500
1800
2000
2500
0 DEG
275
350
400
475
525
600
725
850
1000
5 DEG
375
450
525
600
675
750
900
1050
1160
10 DEG
450
550
650
725
825
900
1075
1250
1440
15DEG
550
650
750
850
975
1075
1300
1500
1850

SKETCH B - MINIMUM PAN AND FEEDER LENGTH

SIZE
VGF 800
VGF 900
VGF 1100
VGF 1200
VGF 1400
VGF 1500
VGF 1800
VGF 2000
VGF 2500
Size of
800
900
1100
1200
1400
1500
1800
2000
2500
feed
deck
width
Grizzly
1600
1700
1800
2000
2400
2500
2600
3000
3200
length
Total
2800
3000
3300
3600
4200
4400
4600
5600
6600
length
Grizzly
50/
50/
50/
507
507
507
507
507
507
bars-
150
180
200
200
250
250
300
350
400
openings
Max. feed
500
600
700
800
1000
1100
1200
1400
1600
size mm
Max.
250
350
400
480
640
750
1040
1200
1400
capacity
TPH
Horse
15
20
25
30
30
40
50
75
100
power
Wt.
3500
4200
5200
6500
8800
9800
12200
14600
16200
Kgs.

FEATURES

Massive welded frame to withstand extreme shock loads.
Conveying deck with pan and grizzly combination, back and side renewable liners.
Non-plugging and stepped grizzly, separately renewable, for material tilting and easy fines passing.
Vibrating unit consisting of two contra-rotating eccentric shafts, geared together in oil-bath. Special roller bearings in oil-bath and protected by    grease labyrinths.
Setting of amplitude is effected at still machine by varying unbalance.
Actuation is by 4-pole motor and V-belts drive.
Special steel springs arranged for the installation on concrete or steel supporting structure.
Welded plate supporting structure (supplied upon request), cross-breams and steel-sections preset for feed and fines discharge hopper application. It is possible to insert a device for continuous output setting.

VIBRATING GRIZZLY FEEDER
MODE
A
B
C
D
E
F
G
VGF 800
2800
800
1950
535
730
1290
1180
VGF 900
3000
900
2200
560
780
1350
1300
VGF 1000
3300
1100
2400
590
800
1400
1450
VGF 1200
3600
1200
2510
590
875
1460
1620
VGF 1400
4200
1400
2935
675
1000
1640
1800
VGF 1500
4400
1500
3100
700
1020
1720
2100
VGF 1800
4600
1800
3180
790
1190
1880
2275
VGF 2000
5600
2000
3500
900
1200
2000
2400
VGF 2500
6600
2500
4100
1100
1500
2200
2600
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