JAW CRUSHER

• Crusher• Crusher is size reduction equipment A crusher is a machine designed to reduce large rocks into smaller, more manageable particles.

• Crusher is a machine which is used to crush heavy size particle into small size, also it’s a primary size reducer.

• Crusher are low speed machine for coarse reduction of large particles

• Approx. size of reduced of material from a crusher ranges from 150mm to 250 mm.

• Working Principle Of A Crusher

• A crusher uses compressive force

for breaking of particle.

• This mechanical pressure is

achieved by the two jaws, one jaw

is kept stationary and is called a

fixed jaw while the other jaw,

called a swing jaw, moves back and

forth relative to it.

• Types Of Crushers

• Jaw crushers

• Gyratory crushers

• Difference

• Difference between these jaw

crushers is the feed rate and

product rate and design, we are,

however, going to talk about jaw

crushers in this particular

presentation.

• Jaw Crusher

• Jaw crusher is a type of crusher

which produces coarse particle.

• Feed size of the jaw crusher is

1500mm-40mm and the product size is

from 50mm-5mm.

• Compressive strength of jaw

crushers is 320 mega Pascal.

• Rpm for jaw crusher is between 200-

400.

• Jaw Crushers

• Jaw crushers are heavy duty

machines and hence need to be

robustly constructed.

• The outer frame is generally made

of cast iron or steel.

• The jaws themselves are usually

constructed from cast steel.

• They are fitted with replaceable

liners which are made of manganese

steel.

Figure 1

• Working Principle Of A Jaw

Crusher

• A jaw crusher uses compressive

force for breaking of particle.

• A Jaw Crusher reduces large size

rocks or ore by placing the rock

into compression. A fixed jaw,

mounted in a "V" alignment is the

stationary breaking surface, while

the movable jaw exerts force on the

rock by forcing it against the

stationary plate.

• Working Principles

• The space at the bottom of the "V"

aligned jaw plates is the crusher

product size gap, or the size of

the crushed product from the jaw

crusher. The rock remains in the

jaws until it is small enough to

pass through the gap at the bottom

of the jaws.

• The Crushing Chamber

• The volume or cavity between the

two jaws is called the crushing

chamber.

• The movement of the swing jaw can

be quite small, since complete

crushing is not performed in one

stroke.

• The inertia required to crush the

material is provided by a weighted

flywheel that moves a shaft

creating an eccentric motion that

causes the closing of the gap.

• Jaws

• Angle between two jaws is between

20-30 degree.

• Larger lumps caught between upper

part of the jaw and broken into

small piece by impact force.

• Small pieces come to narrower space

at the bottom where compressive

force do a sufficient size

reduction and product obtained.

• Types Of Jaw Crusher

• Jaw crusher is classified into two

types.

1.Blake Jaw crusher

2.Dodge jaw crushers

• Both Crushers employs a compressive

force for size reduction.

• Blake Jaw

Crusher

• In Blake jaw

crusher, the

swing jaw is

pivoted at upper

position, the

greatest amount

of motion is at

the bottom which

means less

choking

• Dodge Jaw

Crusher

• In dodge jaw

crusher, the

swing jaw is

pivoted at

bottom

position, it has

a greater

tendency to

choke

• Blake Jaw Crusher

• The Blake type jaw crusher has a

fixed feed area and a variable

discharge area.

• Greatest amount of motion is at the

bottom of v which means that it

have a little tendency to chock.

• Single Toggle Jaw Crusher

• In the single toggle jaw crushers,

the swing jaw is suspended on the

eccentric shaft which leads to a

much more compact design than that

of the double toggle jaw crusher.

• The swing jaw, suspended on the

eccentric, undergoes two types of

motion- swing motion towards the

fixed jaw due to the action of

toggle plate and vertical movement

due the rotation of the eccentric.

• Single Toggle Jaw Crusher

• These both motions, when combined,

lead to an elliptical jaw motion.

This motion is useful as it assists

in pushing the particles through

the crushing chamber.

• This phenomena leads to higher

capacity of the single toggle jaw

crushers but it also results in

higher wear of the crushing jaws.

• These type of jaw crushers are

preferred for the crushing of

softer particles.

• Double Toggle Jaw Crushers

• In the double toggle jaw crushers,

the oscillating motion of the swing

jaw is caused by the vertical

motion of the pitman.

• The pitman moves up and down. The

swing jaw closes, it moves towards

the fixed jaw when the pitman moves

upward and opens during the

downward motion of the pitman.

• This type is commonly used in

mines due to its ability to crush

tough and abrasive materials.

• Doge Jaw Crusher

• In the Dodge type jaw crushers, the

jaws are farther apart at the top

than at the bottom.

• which form a tapered chute so that

the material is crushed.

progressively smaller and smaller

as it travels downward until it is

small enough to escape from the

bottom opening.

• Doge Jaw Crusher

• Greatest amount of motion is at the

top of V which leads to chocking.

• The Dodge jaw crusher has a

variable feed area and a fixed

discharge area which leads to

choking of the crusher.

• used only for laboratory purposes

and not for heavy duty operations.

figure

• Advantages Of Jaw Crusher

• Simple construction makes for easy

maintenance

• Stable performance

• High crushing ratio

• Low operational cost

• High capacity

• Adjustable discharge port

• Industrial Applications

• Crushers are used

1.Heavy duty mining

2.Cement industry

3.Fertilizers industry

4.Plaster of Paris Plant

5.Animal (Cattle) Feed plants

6. Herbal plants

7.Cement plants

8.Ceramic Plant

• Industrial Applications

• Coconut Shell Plant

• Salt Plant

• Mines and Minerals

• Agro Based industries

• Others where size reduction

required

• Gyratory Crushers

• Gyratory crusher looked like a jaw

crusher with circular jaws between

which material is being crushed

some point all the time.

• Rpm is 125-425 gyration per minute.

• Give a continuous discharge because

some part of the crushing head

working all the time.

• Produces up to 4500 ton per hour of

material being crushed.

• Gyratory Crusher

• A gyratory crusher is similar in

basic concept to a jaw crusher,

consisting of a concave surface and

a conical head; both surfaces are

typically lined with manganese

steel surfaces.

• The inner cone has a slight

circular movement, but does not

rotate; the movement is generated

by an eccentric arrangement.

• Gyratory Crusher

• As with the jaw crusher, material

travels downward between the two

surfaces being progressively

crushed until it is small enough to

fall out through the gap between

the two surfaces.