- Construction, mining and quarrying
- Cost varying form material to material to be ripped
- Hard rock
- Compared with drilling, blasting
- Life of ripping tips as well as shortening of undercarriage should be considered.
Characteristic of the material to be ripped influence the selection of ripper type:
- Number of shank required
- Ripping speed
- Amount of ripper penetration
Ripper types
- Various type rippers are used in the dozers
- Towed units – cable operated
- Integrated units – hydraulic operated
- Backrippers – mounted on frame of the dozer – high duty
- Intergral rippers two types
- Hinge type
- Parallelogram type
- Tip can be replaced, it protects shank and adopter from damage.
- When adopter is damaged, next shorter tip so as to reduce the load on the adopter.
- Protector provides the support to the tip and wear protection to the adopter
- When protector worn out to 6mm
- Protector failure – adopter damage
Ripper classification
- Fixed multiple shank ripper
- Variable multiple shank ripper
- Fixed giant ripper
- Variable giant ripper
- Fixed multiple shank ripper -simple ripping operation
- Shank moves – up & down
- Digging depth adjustable
- Fixed Giant ripper: single powerful shank
- not common compare to variable giant ripper
- Variable multiple shank ripper: change the angle
- used where there are many boulders or quality of rock not constant
- The variable giant ripper: single powerful shank
- Angle of ripper changed according to ground requirements
Ripping efficiency
- When material is broken, loosen the surface in one direction, then cross ripping should be adopted
- If material is soft use multiple rippers
- Ripping should be downhill
- Avoid reversing when shank is in ground
- When both dozing and ripping operations are required to be done, it should rip going out and doze on the way in
- Shank tip should be sharp
- Use a low gear range
- When the track start slipping, ripper and shank should be raised
- For the hard material use shorter tip, for a ordinary work use longest and sharpest point
- Do not uncover the unripped portion of the rock during dozing of the material loosened by ripping.
Rippability
- It has been established that rippability of most the rocks are related to the speed at which the sound wave travels through the rock.
- Sound travels faster in a dense medium i.e. the greater the speed the greater is the hardness of material.
- The speed of sound can be determined by the ‘refraction’ seismograph.
- Thus rocks which propagate sound waves at low velocities are rippable, while rocks which propagate waves at high velocities are not rippable.
- Marginal rocks – blasting or drilling – correct size of ripper and capacity of tractor
- Cost of earth excavation, without rock is very less as compared to excavating a rock by ripping.
- life of undercarriage components will be shortened
- These factors need be considered while determining the ripping cost.
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