Why VSI?
The Vertical Shaft Impact Crusher
The proper choice for today's superpave specifications and industry needs.

From the earliest days of road building, crushing rock and precious ores, the world has been looking for the easiest and most economical way to produce the ultimate rock products. With the rising costs of labor, electricity and fuels, there is very demanding need for increased production at lower costs. In today's building materials market, the specifications for concrete aggregates, manufactured sand, asphalt mixes, and road bases have become so precise that you cannot really compete in rock products, precious ore milling, and pharmaceutical minerals without the proper crushing equipment. The answer? A vertical shaft impact rock crusher.


The VSI rock crusher benefits include outputting the cubical shape required for today's specifications, gradation control, variable production versatility in making fines or coarse materials, high product yield with low horse power per ton, non-plugging with wet, muddy materials, and low capital investment and cost per ton of material.

Check out the testimony of one of our production partners telling why they switched to a Canica VSI rock crusher in the video "SHOW ME."

Also, see the video "VSI WEAR PARTS BUZZ" to see and hear the true story of VSI wear parts costs.

 

How does a Canica Impeller and Anvil VSI rock crusher work?
The material enters through the feed tube and drops onto the distribution plate that divides the material equally between the impellers. The impeller then accelerates the material to a stationary anvil that is positioned at a set angle and distance to achieve maximum reduction for a prescribed application. The material hits the anvil once and then falls freely to the discharge area below. Because of the "true impact crushing" process, the machine does not retain the crushed material. This eliminates the high cost of grinding or recirculation rock in the crushing chamber. It also allows a lower horse power requirement, less wear, and a higher product yield.

 

 

The following is a comparison of other types of rock crushers:
CONE CRUSHER
The material enters the crushing chamber by contacting the feed plate. The feed plate distributes the stone equally around the mantle and concave. As the mantle oscillates, the material is crushed by the squeezing action between the mantle and concave. Sizing of the stone can be changed by increasing the closed side setting to generate large stone or by decreasing the closed side setting to make smaller stone. The normal reduction ratio is a 4 to 1. For proper reduction and consistent product gradation, the crusher must be choke fed at all times. If it is not choke fed, the liners will wear unevenly and can cause mechanical problems in the future and will not make consistent output gradations. Other disadvantages are very poor particle shape, and an inability to handle wet, sticky feeds.

 

HORIZONTAL IMPACTOR
The material falls into the feed opening. The rotating hammer hits the material which drives it into the primary impact plate. The crushed material then falls into the grinding zone. Hammers grind the material against the grates until the material is small enough to pass through the grate openings. This results in high wear, tremendous horse power draw and substantial gradation changes as the parts wear.

 

ROCK-ON-ROCK VSI
The material enters through the feed tube into a closed rotor assembly. Then it is thrown against an angular rock bed and is struck by other rock being thrown by the rotor. With the swirling action of the material, it shapes the rock into a more cubical product with some fines generation. As a result of the designed crushing action, a high rotor R.P.M. is necessary, resulting in high horsepower requirements for fines yield.

 

Why is an impeller and anvil VSI the right crusher choice?
We all know that crushing rock with impact crushers gives a cubical particle shape and high fracture percentages. Furthermore, the Canica impeller and anvil VSI is the right tool for fines production and prepping material before ball mills because:

  • The patented geometric design of the crushing chamber requires less horsepower due to slower RPMs of the impeller table. This results in higher fines yield per horse power.
  • Due to a higher first pass production, the recirculation loads are lower. This allows for a high screening efficiency.
  • One problem with impact crushing is the gradation will change. When the wear parts are new, there will be high fines production. As the wear parts are worn, the amount of fines decrease. With the impeller and anvil VSI, the geometry of the wear parts are such that they wear at approximately the same angles as they were when new, making gradation changes minimal if at all. This keeps fines production and screening efficiency up.
  • Many crushing chamber configurations are available for applications, such as different table diameters, 3,4,5 shoe impeller tables and different impeller designs. Anvil rings are also available with different diameters to fit anvils that are one-way or two-way reversible or vaulted for specific crushing needs.
  • There is a selection of feed tube sizes for the proper distribution of material to the impellers for controlling air flow and feed volume.