Rock crushers

Details Rock crushers Rock crushers

2000-11-06

2004-08-31

Rosenbaum, Mark (Department: 3725)

Solid material comminution or disintegration

Apparatus

Stationary comminuting surface or material bed

C241S285300

Reexamination Certificate

active

06783092

ABSTRACT:

TECHNICAL FIELD
This invention relates to improvements to rock crushers.
In particular, the present invention relates to improvements in rotary) impact rock crushers which provide a greater control over the fracture mechanisms and the grade of rock product.
BACKGROUND ART
The many end use applications for rocks require that a range of rock grades are available for use.
The desirable characteristics of a rock product are that it is shaped and graded to suit the duty for which it is required and the strength of the rock is maximized.
The desirable crushing characteristics of a crusher are that there is a high size reduction of the rock, shape and strength of the rock product are maintained or improved and that the crush can be controlled to maximise the desired end product.
There is generally a large compromise between what a crusher will make and what rock product is required. High reduction generally gives poor shape and low strength rock which are undesirable. Low reduction generally gives good shape and high strength which are desirable but high by-product and low output which arm undesirable.
It is common to create a by-product in order to make a specification rock product. This by-product is expensive to produce, has low commercial value and sometimes high environmental costs.
It can be seen that there will be a balance between these characteristics as to which best suits
a) the rock product required; and
b) the crusher making it.
The current problem is that
specifications for rock products are becoming much tighter.
existing crushers lack the control to make a variety of tight specification products at a high rate or without by-product.
Finishing crushers generally fall into the following categories:
Cone Crushers, where rock is crushed by compression between two eccentric metal cones. These machines have good reduction but do not produce fine sand or have good shape.
Hammermills, where rock is crushed by impact with metal hammers attached to a rotor on a horizontal shaft to metal anvil linings in the crusher casing. These machines have high operating costs and the rock product changes rapidly as the crusher wears, i.e. they will not hold the desired rock product specification.
Anvil VSIs, where rock is thrown by a metal impeller (referred to as a rotor) onto metal lining, and is crushed by impact. These machines have good reduction but high operating costs, lower rock strength, bad shape, and won't hold a desired rock product specification as they wear. Anvil VSIs must also be stopped frequently in order to replace worn anvils, which results in expensive down-time.
Rock on Rook VSIs, where rock is crushed by impact with a rock lined impeller (known as a rotor) on a vertical shaft to rock linings in the crusher casing. These machines have high rock strength good shape and produce good sand but have low reduction, and often produce high by-product (unwanted product).
The main reason for low reduction in the Rock-on-Rock VSI is explained as follows. Rock ejected from the rotor is flung out into the crushing chamber where it strikes the rock bed and circulates in the chamber forming a rock swirl.
Rock on rock crushing occurs when rocks ejected from the rotor impact against rocks in the rock swirl. The greatest impact occurs when there is the greatest possible speed differential between the ejected rocks and the swirling rocks. Generally, the swirl moves rapidly in the same direction as the ejected rock and therefore the motion of the rock swirl particle reduces the impact force between the rock swirl particle and the rock ejected from the rotor.
VSI crushers provide some control over the rate of the rock swirl by variation in speed only (reducing rotor speeds which sacrifices output, and reduction).
Cone and Hammermill crushers only control a specific gap in which rock is crushed which has no control over the rock fracture mechanism.
The Applicant has compiled the following table, subjectively depicting the advantages and disadvantages of each crusher type.
The points given are subjective with the greater number of points, the higher the performance.
TABLE 1
Stan-
Short/
Rock on
Hammer-
Possible
dard
Fine
Rock
Anvil
mill/
Points
Cone
Cone
VSI
VSI
Impactor
Performance
Feed Size
4
4
1
2
4
3
Dust Production
4
1
2
3
3
2
Chip Production
4
3
2
3
4
2
Product Shape
4
2
2
4
2
3
Product Control
4
2
2
2
2
2
Cost
Wear Rate
6
6
5
6
1
1
Power
3
3
3
1
2
2
Consumption
Capital Cost
8
1
2
4
2
6
Installation
Height
2
2
2
1
1
2
Weight
2
1
1
2
1
2
TOTAL
41
25
22
28
22
25
Clearly if a crusher could combine the characteristics of one crusher one day to make product ‘X’, and be changed in a controlled way to provide the characteristics of a different crusher on another day to make product ‘Y’ this would be a useful advancement of the art.
It is an object of the present invention to address the foregoing problems of at least to provide the public with a useful choice.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.
DISCLOSURE OF INVENTION
According to one aspect of the present invention there is provided a rotary impact rock crusher having componentry which includes
a crushing chamber housing, and
a rotor into which rock may be introduced and ejected therefrom positioned in the crushing chamber housing,
the rock crusher characterised in that
the relative angles of at least one of the crusher components is adjustable with respect to the vertical.
In some embodiments, the present invention may be configured so that the rotor angle and the angle of the crushing chamber housing with respect to the vertical are adjustable independently of each other.
In some embodiments, the rotor angle may be varied relative to the crushing chamber without departing from the scope of the present invention.
In preferred embodiments, the present invention may be configured so that the planes of the rotor and the crushing chamber housing are at a fixed relative position to each other so the rotor and crushing chamber housing are moveable together with respect to the vertical
Reference to the componentry angle with resect to the vertical will now be made with reference to the embodiment described in the preceding paragraph, wherein further, the planes of the rotor and the crushing chamber housing arm substantially parallel.
This should not be seen to be limiting in any way, as other arrangements, including those described above may be used according to the present invention without departing from the present invention's scope.
The rotor componentry will be referred to hereafter as the crushing chamber, which is intended to encompass the crushing chamber housing, and the rotor.
Reference to the angle from the vertical may be made hereafter with reference to “the angle” for convenience.
The adjustable angle may include angles in all directions about the vertical.
Reference to a rotary impact rock crusher may be made with reference to any crusher whereby rock is introduced to the crusher and has velocity imparted to it by means of a centrifugal rotor, which then sects the rock at speed onto a crushing surface which may be a rock, a rock bed, an anvil or a combination of these.
The crushing chamber may further include an anvil configured so that rocks ejected from the rotor impact on the anvil.
The rock crusher may be configured so that the crushing chamber angle is adjusted to control The fracture mechanisms in the crashing chamber,
The rock fracture mechanisms may include shatter/impact, cleavage, attrition, and abrasion (terms defined further).
In some embodiments the control of the fracture mechanisms will be chosen according to the desired rock product output from the crusher.
In all rock crushers, a range of rock grades is always present in the product. A particular fracture mechanism will have a fairly predictable effect on rock and result in a particular rock grade. The choice of fracture mechanisms made by the operator may be made to select and maximise a particular grade of product in the product range.
In some

Affiliated with

Also associated with

Rating

Rock crushers does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Rock crushers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rock crushers will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3335493