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Rock Crushers |
The provision of crushed stone for the construction industry has been characterized for a long time by large, heavy and expensive machines. The tendency has been for the industry to become extremely capital intensive and highly centralized. Many towns no longer have a crusher at all. In spite of the plentiful supply of labour and the decentralized nature of both the labour and the demand for stone, the size of stone crushing operations has continued to increase. One implication of this is that ever greater numbers of heavy haulage vehicles are required to make deliveries. The cost of operating these vehicles is now a significant proportion of the delivered cost of crushed stone. It is not uncommon for the transport cost of delivering a load of crushed stone to a point more than 100 km from the crusher to be more than the price of the stone itself.
Beyond a radius of about 50 Km from a large crusher, an accptable income can be derived from a small rock crushing business. The new Rock Crusher can virtually eliminate the cost of transportation and all income goes to labour.
Stone sold in small quantities (part loads) bears a higher price per cubic metre. For instance, 1?2 a cubic metre of crushed stone delivered 50 Km may cost three times as much per cubic metre as a large load.
Double Flywheel Model
This machine can also be fitted with a double flywheel as an optional extra. This is to allow for its use in very hot places where exertion for a long time is exhausting. It is also recommended for places where the people usually have a low body weight or lack physical strength. Doubling the flywheel mass allows the equivalent operation to be done at a lower speed. It also allows for the breaking of larger or stronger stone as it will have twice the power if run at the same speed as a single flywheel machine.
Operation And Maintenance
The Rock Crusher comes fitted with a heavy flywheel with a handle attached to it. Turning the handle causes one of a pair of jaws to move back and forth with tremendous force. Stones are dropped into the top of the jaws. As they are broken into smaller pieces they fall lower down where the jaws are closer together. Eventually the pieces are small enough to fall out of the bottom of the machine. Setting the space between the jaws sets the size of crushed stone produced. Heavy-duty sealed ball and spherical bearings cope with the loads.
The jaws can be adjusted closer to each other at the top and bottom giving more than 20 sizes of stone. To do this, pull out the top pin on the fixed jaw and move it closer to the swing jaw, and put the pin in again. The top has 3 positions: 150mm, 100mm and 50mm. When using a 100mm setting, a larger proportion of the jaw is used at a time. This reduces wear on the lower portion of the jaws and increases output. It is easier to break the small pieces than the large ones so the machine should be set to do as much work as people can handle.
Output
The larger the pieces you want, the higher the throughput. Normally the stone is first broken with a large sledge-hammer to pieces smaller than 150mm x 150mm. The smaller, the better. (It takes less effort to break a large stone with a 10 or 14 pound sledge hammer than with the crusher.) The machine is best at producing the small stones, which is the most difficult task for a hand held hammer. The large pieces are first crushed to about 40mm and stored in a pile. This can be done with a team of 7 at a rate of about 5 cubic metres per day. This is a size is suitable for railway sleeper beds, drains and 'stone pitching' beside the road. LITE reports they get 0.7 cubic metres of such stone per person per day, using a team of 7 people in one team as optimal.
Using quartzite, and setting the jaws to make 25mm pieces, the Rock Crusher can make about 1 litre of crushed stone per minute, or more than one half a cubic metre per day. Some crews make 1 cubic metre of 25mm stone per day (15 wheelbarrows). It's about 30 to 50 times faster than using a hammer and anvil.
To make small stones in the 12mm range it is faster and easier to do two more stages at smaller settings.
When producing sub-5mm stone for terrazzo floors, the throughput is much lower, but the product has a much higher value. The Rock Crusher is well suited to producing small quantities of different coloured stones for terrazzo floors.
Note that a small amount of "crusher dust" is produced at all times.
Division of labor
- 2 people pulling rocks out of the ground or hillside.
- 2 people hauling them to the work site.
- 3 people operating the Rock Crusher, taking turns at the handle.
Experience to date shows that operating the machine with a group of 3 people is best. Stones still have to be dug and transported to the machine by additional people if they are not crushed at the source. The three take turns on the handle in 15-20 minute shifts.
Available Crushers and Trailer:
Manual: 150 x 150mm (hand-turned flywheel, makes: 8mm to 35mm stone)
Double Flywheel: 150 x 150mm Double flywheel (makes: 8mm to 35mm stone)
Electric: 380 VAC, 3-Phase
Trailer: Bottom dumping. Low speed (35 kph) - 5-tonne, manual release. Suited for labor-based road construction and maintenance, tractor pulled.
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| Item # |
Description |
Price |
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| MM12729 |
Single Flywheel Rock Crusher |
$1,696.25 |
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to Cart
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| MM10427 |
Double Flywheel Rock Crusher |
$2,231.37 |
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to Cart
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| MM11029 |
Electric Rock Crusher |
$3,648.53 |
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to Cart
|
| MM11743 |
Rock Crusher Trailer - Bottom Dumping |
$3,192.47 |
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to Cart
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Single Flywheel Rock Crusher
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Double Flywheel Rock Crusher
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Double Flywheel Rock Crusher
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