Hydraulic Rock Splitting
--- A New Method for Breaking Rock without
Vibration. —
How tool works
A piston rock splitter machine is composed of a
power pack and one or more number of splitting cylinders connected with
hoses. Each power pack is driven by
electric motor supplied by 380(400)VAC 3
phase or 220(240)VAC single phase power
source. Splitting cylinders are connected to the powerpack through hoses of low pressured and high pressured .Splitting cylinders are sized to fit the pre-drilled holes of 90mm
diameter or larger ( 95,100,105 mm diameter holes)
The splitting cylinders are inserted into the
pre-drilled holes. Then the pistons expand as the hydraulic pressure
force is activated. When the expanded pistons crack the rock ,the rock is
fractured to be crushed.
Pic-1
Pic-2
Pic-3
Pic-4
Pic-5
pic-6
Pic-1 
Pic-2
Pic-3
Pic-4
Pic-5
pic-6
As we see on above pic 1~6, pistons are rising or falling by hydraulic pressures. When high pressure is activated, the pistons rise while low pressure is activated, pistons fall down. The cylinders in the drilled holes are smaller than the drilled holes by 10~15mm in diameter. When the holes are drilled 90mm diameter, the piston cylinders have 80mm diameters. Usual stroke of each piston has 25~35mm depending on the cylinder rod diameter.
Drilling is done by a separate rock drill . Crushing ( or mucking) the rock is done by a breaker or an excavator.
Then crushed rocks are removed from the site.
The holes are made
vertically or horizontally with some angles or straight. Usually horizontal drilling is made
for large volume work. Vertical drilling is made in an inevitable case such as shaft digging, trench work or quarrying sites.
Hydraulic
Power Pack
Hrd-tech has been offering a very sturdy and
reliable power pack among its kind. The
hydraulic power pack is driven by electricity of AC power ( either 380V3phase
or 220V single phase,50/60HZ). A power pack supplies the hydraulics to the
pistons of cylinders. This power pack must be a proven one. Its
failure means non-operation of the machine. The power pack should be from the renowned supplier, because it is not like
the ordinary power pack used for lifting jakki .
Hrd-tech.com has been manufacturing custom made
power packs since late 1990’s. The power pack has been improved and improved for its reliability. It is producing hydraulic power upto
2,500kgf/cm2. But it s use is l recommended to limit of 1,200kgf/cm2 pressure for the safety sake.. AC mains power supply required is either 220~240V AC or 380 VAC 3phase. with frequency of 50/60HZ.
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The power pack is accommodated inside the case. A power cord is connected to the power pack socket.
When the green push button is pushed , the electricity is on. Then the motor begins to run. As the motor runs, hydraulics is loaded.
When the lever is directed to left, the high pressure is loaded. When the lever is turned to right, low pressure is loaded. The medium position of the lever means the hydraulics is NOT loaded. Hydraulic oil is returned to the tank without producing any pressure.
Each cylinder in the hole produces expanding pressure of 150MT or more. When multiple cylinders are activated, very high pressing power is produced .
Each cycling of high to low pressing fluid takes
time of 2~3 monutes.
It is a safe machine. It needs very little maintenance of only with regular
cleaning outside. Oil and filters are recommended to replace every 6
months.
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( Hydraulic pressure cracks the
holes of the rock,)
Splitting Cylinders with Pistons--- Splitters
In the early stage of rock demolition, wedge
type splitting tools were used. As a German company DARDA named it as Darda, it has
been known as Darda splitter. Darda has been very effective for concrete works.
Some people used Darda for rock demolition but it took quite a long time because the spacing for rock
hole was so near, lots of small holes had to be made.
Piston Cylinders began to be used in late 1990 mostly in Korea. Korean government restricted to use any explosives for rock removal in residential area or building site.
Usually the holes are drilled with spacing of between 30cm to 60cm . In special hard rock the space is made more closely like 30cm . Soft rocks need more distant like 60cm spacing between holes. In the beginning, holes were made in 95mm or 105mm . The cylinders are made in 85mm or 95mm diameter steel rods. The length of the steel rod has to be limited in its length or weight. THose cylinders were mostly handled by human hands. The weight was set between 30~40 kgs.
( see below size table).
Usually the holes are drilled with spacing of between 30cm to 60cm . In special hard rock the space is made more closely like 30cm . Soft rocks need more distant like 60cm spacing between holes. In the beginning, holes were made in 95mm or 105mm . The cylinders are made in 85mm or 95mm diameter steel rods. The length of the steel rod has to be limited in its length or weight. THose cylinders were mostly handled by human hands. The weight was set between 30~40 kgs.
( see below size table).
Division
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unit
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Manual type
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Mechanical Type
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SR80-10
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SR85-10
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SR85-11
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SR95-06
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SR150-2
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SR185-1
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SR95-10
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SR150-08
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Cylinder Diameter
|
mm
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80
|
85
|
85
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95
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150
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185
|
95
|
150
|
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Length of Cylinder
Excluding. handle
|
mm
|
650
|
745
|
810
|
525
|
300
|
195
|
705
|
1000
|
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Weight of Cylinder
Including. handle
|
kg
|
27
|
30.8
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32.5
|
29
|
36
|
35
|
39.3
|
125
|
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Number of Pistons
|
#
|
10
|
10
|
11
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6
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2
|
1
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10
|
8
|
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Diameter of
Pistons
|
D1
|
mm
|
38
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40
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40
|
45
|
58
|
90
|
45
|
58
|
|
Force
|
piston
|
ton
|
18.2
|
20.8
|
20.8
|
28.5
|
58.8
|
114
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28.5
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58.8
|
|
cylinder
|
ton
|
182
|
208
|
229
|
171
|
117.6
|
114
|
285
|
470
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Required
Hole diameter
|
mm
|
90
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95
|
95
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105
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165
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200
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105
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165
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Applying force
|
Kgf/cm2
|
1,200
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1,200
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1,200
|
1,200
|
1,200
|
1,200
|
1,200
|
1,200
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Splitting cylinders are made with special steel. The steel needs special machining unlike normal machine. The structure must stand with the ultra hard impact during its repeated stressing activity. It needs special heat treatment to get temper and tensile flexibility.It should be light and sturdy enough for mannuvoering and protecting its function under high pressure.
Manual type is used with workers’ hands. Manual
type weighs around 30kgs including its handle.Mechanical type is assisted by a
winch or an excavator with some grippers.
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Most popular cylinders are SR85-10 or SR85-10 for medium hard rock splitting. They are rather light but producing very heavy cracking power.
SR95-06 or SR95-07( not listed) is used for very hard
rock splitting. Tunnel job requires SR95 types because of hard rock .
From above table, you can see that SR185-1 produces
the strongest force among all other sizes. Though the total cylinder force
is not big,SR185 has the most powerful cracking force.
Mechanical type is used by limited contractors who need more productive constant work. There is no limit in weight or length. Sizes are built by customer specifications. |
Pre-requisite: Rock drilling work.
Every hydraulic rock splitting, whether it is wedge type or piston type, preparation of rock hole is required. From our experience, rock drilling takes 2~3 times of splitting time. So every rock demolition specialist must study the rock drill job carefully.
here follows several hints for a new entrepreneur.
Every hydraulic rock splitting, whether it is wedge type or piston type, preparation of rock hole is required. From our experience, rock drilling takes 2~3 times of splitting time. So every rock demolition specialist must study the rock drill job carefully.
here follows several hints for a new entrepreneur.
Drilling Holes for Splitting
Rock drilling has been done with many rock
drills. Some of the following methods have been used for hydraulic piston rock
splitting.
Crawler rock drill
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A crawler rock drill has been used for
drilling holes in the rock. It is speedy in deep drilling upto 3 meter
deep. The rod is extendable.
Drills are built for certain range of
drill bit sizes. The drill bit of 90~105mm is to be used for the manual
cylinders.
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Core drill mounted on excavator.
Very hard rocks are drilled with core drills.
Usually large size holes of over 120mm are made by core drills.
Following photo shows core drilling
work. The core drill is mounted on an excavator.
The cylinder diameter is smaller than
the drill size by 15mm .In case of 200mm drill hole, 185mm cylinder is
used. For the 165mm diameter holes, 150mm cylinder is used. As the drilling
takes lots of time, one or two cylinder is enough for splitting job
Drilling pace decides the rock splitting. Drilling pace is determined by several factors: 1. Spacing between holes: 2. Depth of the holes: 3. Splitter's expanding power. 4. Rock's characteristics. For a guide purpose, we recommend to set a spacing of 50cm with manual splitter. For the mechanical splitter, 60cm spacing is recommended. Then based on your experience of some splittings, you can adjust the spacing wider or narrower. |
