A hydraulic intensifier is used to increase the pressure of a liquid (water) which is at low pressure and large volume to a higher pressure and lower volume.
It increases the pressure in a hydraulic circuit to a higher value than the pressure provided by the pump.
These older hydraulic machines required hydraulic liquids which are at higher pressure.
To achieve the high pressure of the liquid, a pump is used. But the pump cannot provide that much pressure, so a hydraulic intensifier is used between the pump and the machine to increase the pressure further.
This high pressure cannot be obtained from the main supply directly. So hydraulic intensifier is located between the pump and hydraulic machines like the pump, lift, and crane.
Construction Of Hydraulic Intensifier:
Fixed Ram Cylinder:
It is the bottom part of the hydraulic intensifier. It is fixed and cannot slide or move.
Sliding Ram Or Cylinder:
The fixed ram cylinder is surrounded by a sliding ram or cylinder. This sliding ram slides up and down on the fixed ram.
Large fixed cylinder:
The sliding ram is surrounded by a Large Fixed cylinder. It is fixed which means it cannot move or slide.
In total there are three cylinders, fixed ram cylinder, sliding ram cylinder, and large fixed cylinder.
in between two fixed cylinders, there is a sliding cylinder.
In the fixed ram cylinder, we have two valves V1 from where the low-pressure liquid is supplied, and the second valve V2 from where the high-pressure liquid is supplied to a machine like a lift or a crane.
There is no valve in the sliding ram or cylinder.
In the large fixed cylinder, there are two valves V3 and V4. V4 is the inlet valve just like V1 from where the low-pressure liquid is supplied and the V3 valve is the exhaust valve from which the low pressure is exhausted.
Both the fixed ram has one inlet and one outlet valve. V1 and V4 are the inlet valves and V2 and V3 are the outlet valve.
The sliding cylinder contains water at high pressure. So high pressure is achieved in the sliding cylinder, then high-pressure water from the sliding cylinder is supplied to the fixed ram, and from the fixed ram high pressure water is supplied to the different hydraulic machines through valve V2.
The large fixed cylinder contains the water from the main supply through the V4 valve and the water also exhausts from valve V3.
Working Of Hydraulic Intensifier:
1) The working of the hydraulic intensifier is started by opening valve V4. When valve V4 is opened large quantity of water at low pressure is supplied to the large fixed cylinder.
2) When low-pressure water is supplied to the large fixed cylinder, it exerts pressure to the sliding ram and the sliding ram moves down and reaches its bottommost position.
3) After that the V2 and V4 valves are closed. One inlet and one outlet valve are closed. In a fixed ram outlet valve is closed and in a large fixed cylinder inlet valve is closed.
4) Then water is supplied through the V1 valve and this water starts filling in the sliding ram. Due to this sliding ram starts moving upward and as it moves upward, water available in a large fixed cylinder is exhausted through valve V3.
The sliding cylinders move upward and reach their topmost position.
5) After that V1 and V3 valves are closed and V2 and V4 valves are opened. As the V4 valve is opened low-pressure liquid enters through the V4 valve and the large fixed cylinder starts getting filled and the liquid exerts pressure on the sliding ram from upwards and the sliding ram starts to move downward.
When the sliding ram moves downward it increases the pressure of the liquid inside the sliding ram and high-pressure liquid is achieved and this high-pressure liquid passes moves downward and enters the fixed ram and then it is supplied to the hydraulic machines through valve V2.
From the downside hydraulic intensifier suction takes place and from the upper side of the hydraulic intensifier, delivery takes place.
6) This process is repeated continuously to convert low-pressure liquid to high-pressure liquid.
Performance Of Hydraulic Intensifier:
P1 = Intensity of pressure of water from supply to the large fixed cylinder (low pressure).
D1 = Outer diameter of the sliding cylinder
A1 = c / s are of sliding cylinder= π/4 * D12
P2 = Intensity of high-pressure liquid in fixed ram.
D2 = Outer Diameter Of the fixed cylinder.
Force exerted by the low-pressure liquid on the sliding cylinder ( in a downward direction)
F1= P1 A1
Force exerted by the high-pressure liquid on the sliding cylinder ( in the upward direction)
F2= P2 A2
Equating the upward and downward forces,
P1 A1 = P2 A2
P2 = P1 A1 / A2
Putting the value of A1 and A2, , we have
P2 = P1 * ( D1 / D2)²
Advantages Of Hydraulic Intensifier:
1) It is compact in size and easy to work and control.
2) It is very cheap to buy and provides very economical operation.
3) It is a very high-speed device and can be started and stopped very rapidly.
4) It is very easy to operate.
Disadvantages Of Hydraulic Intensifier:
1) One of the main disadvantages of hydraulic intensifiers is leakage of the fluid.
2) It requires high maintenance.
3) If corrosive hydraulic fluid is used, it can damage the machinery.
Applications Of Hydraulic Intensifier:
1) It is used in different hydraulic devices like hydraulic press, which is used for bending or cutting different types of forging instruments.
2) Used in Hydraulic Crane, which is used to move heavy weights from one place to another.
3) It is also used in Hydraulic Lift, which is used to lift heavy weights.
Types of hydraulic Intensifiers:
Hydraulic intensifiers are of the following types:
1) Single-Acting Intensifier:
In a single-acting intensifier, a piston is present with a piston rod extending to one side only.
2) Double-Acting Intensifier:
In a double-acting intensifier, a large piston is present with a piston rod extending to both sides of the piston.
3) Air Oil Intensifier:
In an air oil intensifier, the compressed air is replaced by low-pressure oil. This compressed air is used to pressurize a small amount of hydraulic fluid.