 |
HOW VSI WORKS ?
VSI is nothing but a Centrifugal "STONE-PUMP". Stones are fed into centre of the rotor (like water in the centrifugal pump) & stones are thrown outwards towards the periphery by centrifugal force.
Feed material is fed through a vertical tube in the centre of the horizontal rotor rotating at high speed (60 M/Sec to 70 M/Sec) around a vertical axis. Feed material due to centrifugal force starts picking up speed and it starts getting distributed over the distribution cone & as the material travels over the rotor-vanes, towards the periphery attains the same speed as speed of rotor's periphery. At the instant of alighting from the rotor, material attains a velocity which is the resultant of peripheral velocity and radial velocity (due to centrifugal force) and direction of the resultant velocity is almost 45 degrees to radial direction.
Kinetic energy of these feed particles, is so high that after impact, against the breaking surfaces stresses developed within the particles overshoot their ultimate strengths and thereby particles disintegrate into number of pieces giving rise to new surfaces.
|
|
IT IS THE VELOCITY & VELOCITY ALONE DECIDES THE AMOUNT OF FRAGMENTATION
Therefore VSI is in true sense a Pure Impact Crusher which crushes only by Impact. Not like other conventional Impact Crushers, where shear, compression, attrition & impact allocations, play the role in crushing the material.
In VSI there is no gap setting. Crushed material falls through the annular open ring area by gravitational force only.
ECOMAN manufactures both types of VSIs :
a) STONE-ON-STONE
b) STONE-ON-STEEL
STONE ON STONE TYPE : Rotor is so designed that, stone layer gets formed on the vane & breaking surface is also formed by material built up. Thereby reducing the wear on the vanes & also on breaker walls. But this cushioned surfaces, reduce considerably the amount of crushing. But amount of spare consumption also gets reduced.
STONE ON STEEL TYPE : In this type of VSI, material glides on the metallic steel vanes & after getting released from rotor, hits on the metallic steel surfaces. Naturally wear on, vane surfaces & breaker surfaces is high. Bigger feed sizes upto 100-150 are possible. Ratio ot reduction is high. |
|
| POINTS TO REMEMBER |
 1 |
One should clearly understand, that Stone-on-Stone V.S.I, is primarily a "SHAPING MACHINE" & nota harsh heavy reduction crushing machine. Heavy size reduction has been intentionally avoided in .. Stone-On-Stone V.S.I, by providing a "SOFT CUSHIONED IMPACT", so that, material is not reduced la to desired product size in one pass, but it attains the desired product size, only after 3-4 passes ormore, This has been done intentionally. |
| 2 |
Therefore quite a high recirculating load is essential. And that is how cubical shape achieved by 9 stone-stone type V.S.I, is very much superior to cubical shape obtained by any other existing ; i crushing equipments. |
| 3 |
Therefore, throughput capacities are very high and should not be confused with the ultimate product out-put capacities. Invariably throughput capacity has to be 1.5 to 5 times of output capacities. For instance, sand manufacturing V.S.I, of output capacity of 20 TPH, should have say 100 TPH throughput capacity.
Therefore, capacities of feeding equipments and recirculating equipments should be based on throughput capacities and not on output capacities. |
| 4 |
Ensuring of no over sized material is fed to V.S.I, is very vital. Even occasional, one piece or two pieces can be harmful, as these pieces may choke up in the feed tube or block the passages in the rotor. Rotor will get imbalanced & if continued to run further may damage the bearings.
Therefore pre-screening prior to feeding into V.S.I, is very essential. Even cardboard pieces, papers, clay lumps & cotton waste etc., can block the passages. Upper limit of feed size, i.e. maximum feed size should be very strictly controlled. |
| 5 |
Feeding continuously, without interruption at rated throughput capacity gives best results. It increases outputs & shape of aggregates, gets further improved. |
| 6 |
Surface velocity of rotor decides the ratio of reduction. For finer end product, higher speeds are required. For standard aggregates, 45 m/sec is good speed but for finer products higher speeds even upto 70 m/sec to 80 m/sec are used. |
| 7 |
It is very much advantageous & advisable to make provisions in the crushing circuit, in such a way that all the separated sizes in desired proportion you should be able to feed back to V.S.I, to
improve shape further and to get desired grain analysis in the product. (You may say to achieve desired F.M.). |
| 8 |
As the material is always flowing over the material bed and impacting also on material built-up, wear & tear on the components is minimised & therefore spare parts consumption per ton of aggregates produced is very low; especially when compared with conventional impactors. |
| 9 |
In case of bigger size V.S.I.'s twin motor drive should be selected. One motor will bring the V.S.I, to full speed, then the other motor is brought into operation. Thereby starting heavy currents are reduced considerably. This arrangement is very useful especially when plant is run of D.G. Set. |
|
|
| Crusher Dimensions in mm |
TYPE |
A |
B |
C |
D |
E |
F |
G |
35 |
1630 |
900 |
791 |
300/594 |
1104 |
1600 |
3400 |
55 |
1866 |
1643 |
798 |
500 |
1690 |
2600 |
4550 |
80 |
1866 |
1643 |
798 |
500 |
1690 |
2600 |
4550 |
110/160 |
2484 |
1659 |
978.5 |
- |
- |
2800 |
4170 |
220/330 |
3005 |
2439 |
1178 |
606 |
2006 |
- |
- |
|
| Crusher data |
TYPE |
35 |
55 |
80 |
110 |
160 |
220 |
330 |
Max.feed size |
0-30 |
0-35 |
0-35 |
0-40 |
0-40 |
0-50 |
0-50 |
R
O
T
O
R |
Diameter in mm |
610 |
780 |
780 |
1000 |
1000 |
1200 |
1200 |
Surface speed m/sec |
30-62 |
45-65 |
45-65 |
45-65 |
45-65 |
35-55 |
35-55 |
RPM |
1300-2000 |
1320-2000 |
1320-2000 |
1030-1670 |
1030-1490 |
640-990 |
640-990 |
Power in KW |
55 |
75 |
90 |
160 |
200 |
250 |
300 |
V-Belts |
4xXPB |
5xSPC |
6xSPC |
6xSPC |
6xSPC |
8xSPC |
8xSPC |
Wt. in Kgs. approx |
2800 |
3200 |
3800 |
5800 |
6000 |
6900 |
7000 |
|
Motor Pulley |
236 |
250 |
265 |
4000 |
400 |
540 |
540 |
|
| Production Capacities (depend on material & feed size , approx valuse) |
|
TYPE |
THOUGHTPUT
|
PRODUCT THOUGHTPUT |
0-2 mm |
0-4 mm |
35 |
40 tph |
8-12 tph |
15-20 tph |
55 |
70 tph |
12-16 tph |
20-25 tph |
80 |
90 tph |
16-24 tph |
23-30 tph |
110 |
130 tph |
25-30 tph |
35-40 tph |
160 |
160 tph |
30-40 tph |
50-70 tph |
220 |
220 tph |
50-70 tph |
70-90 tph |
330 |
280 tph |
70-90 tph |
110-130 tph |
|
|
 |
Closed Rotor
(Welded Construction)
 Material Build up
Main Body
Wear Components
Hard facing (Reduilding ) |
Open Rotor
(Bolted Construction )
Main Body
Wear Components |
|
|
| Life of tips with different application. |
| Product - 0-4 |
Mineral |
Hre Apprx. |
|
1500-1300 |
Mineral with 60-90% Quartz
|
500-1500 |
Klinker |
4000-8000 |
|
1000-7000 |
Limestone |
4000-12000 |
Corundum |
250-500 |
Blast Furnace Slog |
3000-4000 |
Bauxite |
500-1000 |
Above Non-binding values vary considerably. |
|
|
|
|
|
