Abstract
The Design and Fabrication of a Hydraulic Ram Pump (Hydram) is undertaken. It is meant to lift water from a depth of 5 feet below the surface with no other external energy source required. The overall cost of fabrication of this hydram shows that the pump is relatively cheaper than the existing pumps.
Chapter 1
INTRODUCTION
1. 1 Historical Background:
The first hydraulic ram pump was invented by John Whitehurst in England in 1772. This pump was non-self-acting. In 1796 a Frenchman, Joseph Michael Montgolfier, had added a valve, which made the device self-acting.
In 1809, the first American patent was issued to J. Cerneau and S. S. Hallet . Prior to the 1840’s most ram pumps in America were imported from Europe, but in 1843, H. H. Strawbridge of Louisiana put an American made model into use.
Rural communities in America found the features of the pump very attractive. Articles in magazines brought further recognition and understanding of the ram and its possibilities. A detailed book on the ram, published in 1842, was in its 16th edition by 1870.
In 1879, The People’s Cyclopedia included the hydraulic ram among the 55 most important inventions in the history of mankind. It defined the hydraulic ram as: ” A simple and conveniently applied mechanism by which the weight of falling water can be made available for raising a portion of itself to a considerable height.”
Patents on the ram abounded in the 1840’s and 1850’s, but after 1858 none were secured until 1870 when another burst of interest saw four patents awarded in 3 years.
Cost was a major factor in the growth of ram use. Not only were the machines inexpensive to buy, but they also were simple to install and were almost maintenance-free.
For more than 100 years rams were major movers of water to homes, farms, industries, railroads and towns. They contributed to improved crop production, introduction of extensive landscaping and, perhaps most importantly, to health and sanitation.
With the advent of electrical pumps, interest in the hydraulic rams became dormant. Ram pumps were allowed to rust in the stream until expensive parts, fossil fuel shortages, and environmental concerns brought back to the public’s mind the need for a pump that is
inexpensive, requires almost no repairs or maintenance is self-acting, and can raise water to a considerable height vertically. Ram pumps are again becoming increasing popular in both developing and developed countries. They are being operated successfully worldwide.
800px-Roscheiderhof-lambachpumpe
Figure An early Hydraulic Ram Pump
1. 2 Hydraulic Ram Pump:
The hydram uses energy of falling water to lift water. There is no separate motor or mechanism that operates the pump. In real life application water is diverted from a water source and made to flow in a straight and sloping pipe, called the drive pipe. The falling action of water causes a gain in its kinetic energy. The gain in energy increases with increase in velocity of water.
The hydram is located at the bottom of the drive pipe. The water flows through its main valve. When this valve closes water is brought to a sudden stop. The kinetic energy gained by water while falling down is converted to pressure energy. This is the energy which all pumps use to lift water. Some amount of the water is pushed into the delivery pipe due to this pressure and delivered where it required is.
Essentially, a hydram is an automatic pumping device which utilizes a small fall of water to lift a fraction of the supply flow to a much greater height; ie it uses a larger flow of water falling through a small head to lift a small flow of water through a higher head.
All hydrams need a large amount of falling water to provide the energy utilized by them. This is why they can only be used when the source is very large compared to the amount of water required to be pumped. Usually, 5 to 10% of the water from the drive pipe is pumped. The rest goes back to the main water source
1. 3 Advantages and Application:
The hydraulic ram pump can be used with great effectiveness in communities which are located at a higher elevation than their source of water. The hydram pump uses the power of falling water to pump a small portion of that water uphill. It requires absolutely no fuel or electricity and operate only water pressure.
There are only two moving parts which are lubricated by the water itself thus making a hydram a very simple device. Hydrams can be used in many diverse situations for example for domestic purposes or irrigation
The source of water supply to the hydram could be a stream, a spring, an irrigation canal, an artesian well, or even an existing gravity flow water system. In the mountainous topography, there are many places where, if a hydram were installed, much time spent hauling water could be used for other purposes.
Formerly unproductive or unused land could be made suitable for cultivation and yields will be increased in existing fields. Wide scale usage can benefit many people.
Because this simple pump works 24 hours per day, for many years and requires little attention, it is suitable for areas where people have little technical expertise. Because hydram installations are inexpensive and quickly installed, they are well suited for remote areas where there are extreme transportation difficulties, as well as for sparsely populated villages which often make gravity flow water supply system financially unfeasible. The ability to incorporate a hydram in an existing gravity flow water supply system has also proved very useful.
1. 4 Limitations:
The use of hydrams has certain constraints associated with it. These are:
Hydrams can only be used in mountainous topography. Where there is enough elevation distance between the water source and the community to which water is to be supplied. Generally the place for pumps should not be more than 100 meters below the place where water must be delivered.
In areas which are prone to inundation, the hydram should be located so that the waste valve (a component of the pump) is always located above flood water level, as the pump will cease to function if the waste valve becomes submerged.
The hydrams pump only a small portion of the water which is supplied to them therefore the source supplying hydram with water should be much larger than the amount of water which is desired to be delivered.
The water source should not be seasonal and be present year-round if continuous supply of water is desired.
Although hydrams are a very cheap technology compared to the more common used electric pumps they can have a high capital cost in relation to other technologies.
Hydrams are limited to small scale applications, usually up to 1kW.
A willingness for system care and maintenance to be provided by the community that uses the water.
Chapter 2
WORKING PRINCPLE
2. 1 Water hammer.
Water hammer (or, more generally, fluid hammer) is a pressure surge or wave resulting when a fluid (usually a liquid but sometimes also a gas) in motion is forced to stop or change direction suddenly. Water hammer commonly occurs when a valve is closed suddenly at an end of a pipeline system, and a pressure wave propagates in the pipe. If the pipe is suddenly closed at the outlet (downstream), the mass of water before the closure is still moving forward with some velocity, building up a high pressure.
When a valve in a pipe is closed, the water downstream of the valve will attempt to continue flowing, creating a vacuum that may cause the pipe to collapse or implode. Here water hammer has a negative impact. Nevertheless, the same phenomenon is used to life water in a hydram
There are two main Physics concepts.
2. 2 Momentum and Impulse.
When an object is moving at some velocity, v, it has a momentum equal to its mass times its velocity, m*v . In our system, when the waste valve closes, the velocity of the water goes quickly to zero. This change in velocity causes a change in momentum equal to m*Δ v. If you divide the change in momentum, also known as impulse, by the amount of time that has elapsed during the change in momentum, you get:
Impulse = m * Δ v / Δ t
Noting that force = m*a, impulse / time equals a force. This force is a constant that can be used to determine the amount of work that can be done on the system.
2. 3 Conservation of Mechanical Energy.
During any type of physical interaction, the energy of the system remains constant. The only type of energy that is applicable here is mechanical energy. Mechanical energy is defined as the sum of kinetic energy and potential energy.
To find the theoretical maximum height the pump can pump to, the final mechanical energy should be all potential energy and no kinetic energy. Therefore we take the equation
1/2 * m * v2 + m * g * hi = m * g * hf
Water enters through the inlet pipe and exits through the waste valve. As it moves through the waste valve it builds up speed / momentum / kinetic energy. When the water gets going fast enough, it pushes the plunger on the waste valve closed. The moment the waste valve closes, the water creates an impulse and pushes up through the one way valve and out towards its destination. Once this built up pressure is released, the one way valve closes and the waste valve opens, starting a new cycle
Chapter 3
OPERATION SEQUENCE OF HYDRAM
The hydraulic ram pump operates in a cycle. The time each cycle takes to complete is very less, often one second. Each cycle of the pump can be divided in four phases. These are explained as follows
3. 1 Acceleration:
Water enters the hydram through the drive pipe and fills the pump body and starts flowing out of the waste or impulse valve. The water flowing past this valve tries to close it. The flow accelerates. During this time the delivery or check valve remains closed and no water is entering the delivery pipe.
A
Drive Pipe
B
Impulse Valve
C
Delivery Valve
D
Air Chamber
E
Delivery Pipe
1
Figure 3. 1 Acceleration
3. 2 Compression:
The velocity and pressure of the column of water exiting from the impulse valve is overcome and the impulse valve closes. This creates a high pressure, compressing the water inside the pump body. This rise in pressure is called ‘water hammer’. The effect of water hammer is to open the check valve.
A
Drive Pipe
B
Impulse Valve
C
Delivery Valve
D
Air Chamber
E
Delivery Pipe
2
Figure 3. 2 Compression
3. 3 Delivery:
The water starts flowing through the check valve in the air chamber. Air trapped in the air chamber is simultaneously compressed to a pressure exceeding the delivery pressure. Once the pressure in the air chamber exceeds the static delivery head due to reexpansion, water is forced up the delivery pipe. The pressure in the pump body drops quickly to equal the pressure in the air chamber thus closing the delivery valve.
A
Drive Pipe
B
Impulse Valve
C
Delivery Valve
D
Air Chamber
E
Delivery Pipe
3
Figure 3. 3 Delivery
3. 4 Recoil:
After the delivery valve has closed, a shockwave is created and causes the water to flow back up the drive pipe. This results in a drop of pressure low enough for the impulse valve to open. Flow through drive pipe starts. The air volume in the air chamber stabilizes by this point and the flow from the delivery pipe stops.
A
Drive Pipe
B
Impulse Valve
C
Delivery Valve
D
Air Chamber
E
Delivery Pipe
4
Figure 3. 4 Recoil
Chapter 4
DESIGN
4. 1 Designs
Design 1
Hydraulic_Ram_Pump_p04a
Figure 4. 1 Design – 01
They tend to be made from heavy castings and have been known to function reliably for 50 years or more. However, although a number of such design is still manufactured in Europe and the USA in small numbers, they are relatively expensive, although generally speaking the drive-pipe, delivery pipe and civil workings will be significantly more expensive than even the heaviest types of hydram.
Design 2
Capture
Figure 4. 2 Design – 02
This design is very low in cost but the pipes in the end cost considerably more than the
hydram. They are not always as reliable as previous design, but are usually acceptably
reliable with failures separated by many months rather than days, and are easy to repair when they fail.
Table Comparison between Designs
Features
Design 1
Design 2
Fabrication
Difficult
Medium
Weight
Heavy
Not too much heavy
Reliability
Yes
To some extent
Fabrication cost
High
Low
Maintenance required
Yes
Yes
Complexity
High
low
Weighting matrix of designs
Not Important
Important
Table Weighting matrix of Designs
Features
A
B
C
D
E
F
TOTAL
WEIGHT
A
–
1
1
1
0
1
4
0. 21
B
1
–
0
1
1
1
4
0. 21
C
0
0
–
1
1
0
2
0. 1
D
1
1
1
–
0
1
4
0. 21
E
0
0
0
0
–
1
1
0. 06
F
1
1
1
1
0
–
4
0. 21
∑= 19
∑= 1
A- Ease of Fabrication
B- Weight
C- Reliable
D- Fabrication cost
E- Maintenance required
F- Complexity
Rating matrix of Design
0 – Does not meet requirement
1 – Meets requirement partially
2 – Fully meets requirement
3 – Significantly above requirement
Table Rating matrix of Designs
Features
Weighting
Design
Rating
I
II
I
II
A
0. 21
1
3
0. 21
0. 63
B
0. 21
1
3
0. 21
0. 63
C
0. 1
3
1
0. 3
0. 1
D
0. 21
2
3
0. 42
0. 63
E
0. 06
1
1
0. 06
0. 06
F
0. 21
1
2
0. 21
0. 42
∑= 1. 41
∑= 2. 47
A- Ease of Fabrication
B- Weight
C- Reliable
D- Fabrication cost
E- Maintenance required
F- Complexity
Considering fabrication, weight, cost, complexity design 2 is selected.
Design 2:
Capture1
4. 2 Parts of Hydram
Tanks
Pipes
Impulse and delivery valve
Air chamber
pump
throttling valve
rubber washers
Pipe Elbows
Pipe collar
4. 2. 1Tanks
We will be using three tanks
Supply tank
Waste water tank
Delivered tank
Supply tank:
The water that to be elevated will be supplied from the supply tank. A pipe with a throttling valve will be connected with it. this tank will be 5 feet from ground and have capacity of 10 gallons.
Waste water tank:
The water that comes out from the impulsive valve will go to waste water tank.
Delivered tank:
This tank would be at the height of 10-12 feet. The water from the delivery tank will go to the delivered tank.
4. 2. 2 Pipes
There are two pipes
Drive pipe
Delivery pipe
Drive pipe:
The water coming from the Supply tank will flow in drive pipe. The flow in this pipe can be controlled through a valve.
Delivery Pipe:
The water at the delivered tank will be delivered through delivery pipe.
Table Price list of different material for pipes
Materials
Length (Feet)
2 in. Dia Cost (Rs)
3 in. Dia Cost (Rs)
PVC
13
560
900
GI (M)
20
3060
4500
GI (L)
20
2600
3250
GI (EL)
20
2350
2900
CI
6
1100
1500
Weighting matrix of pipe
0- Not Important
1- Important
Table Weighting matrix of Pipe
Design feature
A
B
C
D
E
TOTAL
WEIGHT
A
–
0
1
0
1
2
0. 15
B
1
–
1
1
1
4
0. 30
C
1
0
–
1
1
3
0. 23
D
1
0
1
–
1
3
0. 23
E
0
0
1
0
–
1
0. 07
∑= 13
∑= 1
Design Factors
A – Weight
B – Friction factor
C – Cost
D – Assembling
E – Resistance to corrosion
According to matrix friction factor, cost, assembling are important factors.
Rating matrix of pipes
0 – Does not meet requirement
1 – Meets requirement partially
2 – Fully meets requirement
3 – Significantly above requirement
Table Rating matrix of Pipes
Design Factors
Weighting
Concepts
Rating
I
II
III
I
II
III
A
0. 15
3
2
2
0. 45
0. 3
0. 3
B
0. 30
3
3
0
0. 9
0. 9
0
C
0. 23
3
2
2
0. 69
0. 46
0. 46
D
0. 23
1
3
2
0. 23
0. 69
0. 46
E
0. 07
3
3
1
0. 21
0. 21
. 07
∑= 2. 48
∑= 2. 56
∑= 1. 29
Concepts
I – PVC
II – GI (Galvanized iron)
III – CI (cast iron)
Design Factors
A – Weight
B – Friction factor
C – Cost
D – Assembling
E – Resistance to corrosion
According to matrix we might use PVC or galvanized iron
4. 2. 3 Air chamber
Air chamber is to turn the intermittent flow through the delivery valve into steady, continuous flow up the delivery pipe. the air chamber provide the pump with a constant head to pump against and removes the inefficiencies associated with intermittent flow in the delivery pipe . The size of the air chamber therefore should ensure the conditions in the air vessel are little affected by the sudden inflow of water each cycle coming through the delivery valve.
The volume of the air in the air chamber therefore should be at least 20 and preferably nearer 50 times the expected delivery flow per cycle . An air chamber with a volume many times that of the water entering per cycle will experience little change in condition at each delivery. Pump running to low heads with large delivery flows therefore actually require air chamber than ones pumping smaller flows to high delivery head.
4. 2. 4 Pump
A pump will be connected with waste tank that will pump the waste water and delivers it to the supply tank so that if the water level in supply tank gets low , the waste water will be pumped to the supply tank.
4. 2. 5 Throttling valve
A valve will be connected with drive pipe to control the flow of water.
4. 2. 6 Rubber washers
When the valve will close, water should not leak out from it. In order to prevent leakage rubber washer will be used.
4. 2. 7 Pipe elbows & collars
To connect different pipes we will use pipe elbow. Mostly we will use 90o elbow. We will also use welding technology if required.
Price list of different elbow of different materials
Materials
2 inch 90o elbow
3 inch 45o elbow
2 inch 45o elbow
3 inch 45o elbow
PVC
Rs. 50
Rs. 50
Rs. 110
Rs. 110
GI (M)
Rs. 150
Rs. 170
Rs. 210
Rs. 260
GI (L)
Rs. 140
Rs. 160
Rs. 170
Rs. 210
GI (EL)
Rs. 120
Rs. 150
Rs. 165
Rs. 190
CI
Rs. 295
Rs. 295
Rs. 330
Rs. 350
Table List of different elbow of different materials
4. 3 Estimated Cost
Estimated cost of hydram from different materials
MATERIALS
ESTIMATED COST (Rs.)
PVC
10000 – 15000
GI (M)
23000 – 26000
GI (L)
22000 – 24000
GI (EL)
18000 – 23000
CI
16000 – 20000
Table Estimated cost of Hydram from different materials
List of Abbreviation
A1 cross sectional area of supply pipe
A2 cross sectional area of delivery pipe
D1 diameter of supply pipe
D2 diameter of delivery pipe
D Diameter of waste water inlet
d Diameter of waste water outlet
Dv Diameter of valve poppet
F force on waste valve poppet
H supply head
h delivered head
L1 length of supply pipe
L2 length of delivery pipe
∆L Distance of waste valve poppet from the centerline of drive pipe
mass flowrate in supply pipe
mv mass of waste valve poppet
P0 pressure on supply tank
P1 pressure developed due to fall of water
P2 pressure on waste valve poppet
Q volume flowrate
V velocity of water in supply pipe
V1 velocity of water entering hydram
V2 velocity of water leaving hydram
power gained by falling water
Ï density of water = 1000 kg/m3
g acceleration of free fall = 9. 81 m/s2
μ viscosity of water = 1. 12 x10-3 Ns/m2
γ specific weight of water = 9810 N/m3
Abstract
The Design and Fabrication of a Hydraulic Ram Pump (Hydram) is undertaken. It is meant to lift water from a depth of 5 feet below the surface with no other external energy source required. The overall cost of fabrication of this hydram shows that the pump is relatively cheaper than the existing pumps.
Design Selection
During the selection of deign for the hydram the following were considered
Ease of Fabrication
Weight
Reliable
Fabrication cost
Maintenance required
Complexity.
The design was chosen giving priority to fabrication, weight, cost and complexity. The hydram will be fabricated from PVC.
Chapter 5
TECHNICAL DRAWINGS
Capture8
Figure 5.: 3D view of pump
Capture9
Figure 5. : (a) Front view of pump
Capture10
Figure 5.: Front View of Pump
Capture1
Figure 5.: 3D view of waste valveCapture2
Figure . 5 Front view of Waste valve
Capture3
Figure 5. 3D view of Delivery Valve
Capture5
Figure 5. Front view of Delivery Valve
Capture6
Figure 5. 3D view of Air ChamberCapture7
Figure 5. Front View of Air Chamber
Chapter 6
MATERIAL PROPERTIES AND JOINING METHODS
6. 1 PVC pipes and fittings
The difference between Schedule 40 and Schedule 80 PVC Pipe is the thickness of the pipe wall. Schedule 40 has a thinner wall than Schedule 80. This makes Schedule 80 PVC Pipes perfect for applications with very high water pressures.
The outside diameter of the pipes is constant for different sizes and therefore they are interchangeable (provided that they meet the correct strength requirements).
PVC Pipe Fittings differ similarly to PVC Pipe, except that they maintain the same inner diameter with the outer diameter differing based on the Schedule. This means that these are all interchangeable so long as they meet the requirements.
Maximum Pressure
Maximum operating and required minimum bursting pressures at 73oF (23oC) for PVC pipe fittings according ASTM D1785 ” Standard Specification for Poly Vinyl Chloride (PVC) Plastic Pipes Schedules 40 and 80 are indicated in the diagram and table below:
pvc pipes – bursting and operating pressure limits diagram
Figure 6. 1 Graph for the Max. Pressure
PVC
Nominal Pipe Size
(inches)
Required Minimum Burst Pressure
(psi)
Maximum Operating Pressure
(psi)
Schedule 40[1]
Schedule 80[2]
Schedule 40
Schedule 80
1/2
1910
2720
358
509
3/4
1540
2200
289
413
1
1440
2020
270
378
1 1/4
1180
1660
221
312
1 1/2
1060
1510
198
282
2
890
1290
166
243
2 1/2
870
1360
182
255
3
840
1200
158
225
Table 6.: Table Pipe sizes and Max. Pressure
1 psi (lb/in2) = 6, 894. 8 Pa (N/m2)
Chemical Resistance:
PVC pressure pipe and fittings are inert to attack by a wide variety of strong acids, alkalis, salt solutions, alcohols, and many other chemicals. They are dependable in corrosive applications and impart no tastes or odors to materials carried in them. They do not react with materials carried, nor act as a catalyst.
Strength
PVC Schedule 40 and Schedule 80 pipe and fittings are highly tough and durable products that have high-tensile and high-impact strength. They withstand high pressure for long time.
Fire Resistance
PVC pressure pipe and fittings are self-extinguishing, and do not support combustion..
Internal Corrosion Resistance
PVC Schedule 40 and Schedule 80 pipe and fittings resist chemical attack by most acids, alkalis, salts, and organic media such as alcohols and aliphatic hydrocarbons, within certain limits of temperature and pressure.
External Corrosion Resistance
Industrial fumes, humidity, salt water, weather, atmospheric, or underground conditions – regardless of soil type or moisture – cannot harm PVC pressure pipe and fittings. Scratches or surface abrasions do not provide points which corrosive elements can attack.
.
Low Friction Loss
The smooth interior surfaces of PVC Schedule 40 and Schedule 80 pipe and fittings assure low friction loss and high flow rate. Because PVC pipe and fittings do not rust, pit, scale, or corrode, the high flow rate continues for the life of the piping system.
Low Thermal Conductivity
PVC pressure pipe and fittings have a much lower thermal conductivity factor than metal pipe. This ensures that fluids maintain a more constant temperature. In most cases, pipe insulation is not required. [3]
.
6. 2 Joining Methods
There are several techniques for the joining the pipes and fittings.
Solvent cement
Threaded connections
Solvent cement
For joining solvent cement will be used. It is simple and reliable if procedures are followed correctly. Since variables of temperature, humidity, pipe size, time, and other conditions have a significant effect on solvent cement joints, it is important to understand the principles of each step and make adjustments for actual conditions.
A wide variety of solvent cements and primers are commercially available. Selection of specific type, grade and consistency of solvent cement should take into account pipe type, size, installation conditions and chemical compatibility of cement and system fluids.
For best results, installation should be made at temperatures between 10°C and 45°C. All joint components should be inspected for any breaking, chipping, gouging or other visible damage before
Threaded Connections
Threading reduces the effective wall thickness of pipe, pressure ratings of the pipe are reduced to one-half that of unthreaded pipe using solvent cement welded joints. By threading different parts specially the valves can be joined.
Chapter 7
CALCULATIONS
The calculations for the design parameter have been done after carrying out a market survey of the components and materials available. Our aim is to achieve a delivered head of 4 meters from a fall of maximum 1. 5 meters from the supply tank.
The height of the supply tank has been varied to see if the desired delivery head is achieved or not. The calculations are theoretical and the situation will be different practically. The calculations only give a rough estimate of the design parameters. Trial and error will be used to start the operation of the hydram.
The pre defined parameters include
Diameter of drive pipe = 1 inch = 0. 0254 m
Diameter of delivery pipe = 0. 5 inch = 0. 0127 m
Distance of waste valve poppet from the centerline of drive pipe = 0. 1 m
Diameter of waste water inlet = 2. 5 inch = 0. 0635 m
Diameter of waste water outlet = 1. 35 inch = 0. 0345 m
Schematic of Hydraulic Ram Pump Setup
h0Delivery Tank
P0
(1)
L
Hf
<