Design and Implementation of an Innovative Hydraulic Ram Pump Pressure Release Mechanism for the Philippines

Introduction

According to the 2006 United Nations Human Development Report, more than one billion people in the world do not have access to clean water and over two billion people do not have adequate sanitation. This is an ongoing problem in the rural Philippines where rough mountainous terrain makes fetching water an arduous task. The mission of the Northwestern University Ram Pump Team is to provide the rural villagers of Tress Hermanos access to clean running water and sanitation through the implementation of a RAM pump system. The team will be working in conjunction with NGOS Alternative Indigenous Development Foundation Inc-AIDFI and Green Empowerment. AIDFI is an NGO based in the Philippines with over 17 years of experience in ram pump technology and has been utilizing their own (see Figure 1) to improve the lives of many Filipinos. My role on the ram pump team is to 1)offer a solution to a flaw in the currently used model; 2) visit a village where installation is taking place in order to develop appropriate technology and best practices; 3) use data collected from the trip to finalize the model and recommend long-term solutions to the problem. During Spring Quarter I will design the mechanism itself. This summer our team will travel to Tres Hermanos to assist with the installation of the pump and training local residents to use and repair the pump. My project this summer will be to assess the effectiveness of the unjamming mechanism in the field to develop strategies for improving the ease of use and repair. This research will contribute to the further improvement of the design and help promote Ram pump technology as a safe and cost-effective solution to clean water delivery in developing areas.

Hydraulic Ram Pumps rely solely on gravity, pressure, and a phenomenon known as the water hammer effect to pump water from a lower to higher elevation. The pumps main parts consist of a drive pipe, waste valve, check valve, air chamber, and delivery line (see Figure 2). With relatively few moving parts, the ram pump is very rugged which makes it ideally suited for remote locations due to its energy independence.

Previous projects done by AIDFI involving ram pumps included no safe and reliable way of unjamming a waste valve. Solutions included attempting to pry the waste valve open with bamboo sticks or sometimes even hands and feet. Both of these techniques are extremely dangerous. The pressure build up behind the waste valve causes the hinged gate to close with dangerous amounts of force. This could cause serious personal injury and take away from the positive effects of the ram pump itself. Research Questions and Methodology Hypothesis: a lever mechanism that can be manually operated and easily used without additional energy, ie. electrical input, is the best way to solve of the problem of waste valve jamming. There are several options to address this issue. One is to weld a metal component onto the side of the pump so that it can be used conveniently whenever necessary. However, it is likely that a simple, detachable lever system will be best for the rough environment and limited access to tools and materials.

Will the mechanism actually work, and if it does what design features allow it to be easily fixed in the Philippines? This trip will allow quantification of the effectiveness of the mechanism and its ability to solve the problem of waste valve jamming through extensive observations. To quantify the PHFKDQLVPVSHUIRUPDQFHLQWKHILHOGSUHVVXUHPHDVXUHPHQWVZLOOEHWDNHQDWWKHVLWHDQGGHIRUPDWLRQand wear related to stress will be recorded and analyzed. Theoretical calculations have revealed that roughly 220 lbs will be applied to the waste valve door so compressions and tensions in members of the mechanism will have to be recalculated in addition to the computer data using statics analysis. Various

aspects that make the design successful will also be examined to see how it might be improved. A thorough assessment of local repair options will be conducted to help decide what design features could be changed in order to make it easier for the Filipino people to repair it. Through these assessments, I hope to gain deep insight into what makes a versatile design.

What makes the mechanism well suited for its job? Waste valve unjamming involves a half hour trek every time the pump jams. Observing how the Filipino people will deal with this distance carrying a heavy tool will provide insight into design methodology. Much of good design is taking care of the subtle problems that occur when using a design. For example if the villager leaves the tool in a hidden place halfway down the trek to the valve, the design will have to be modified to be able to resist deterioration while fully exposed to the environment. Observing how the Filipino people might adapt the mechanism will also provide insight into design methodology. Will they flip it to the side and gain more leverage? Will they cut off a part and utilize it in a completely different area of the pump? Will it and is it used for other things besides unjamming? Identifying such subtleties is crucial to the design process.

In order to detect subtle changes in design use such as implementation and user habits developed as a result from contact with the design, observations will be extensive and will detail every villager in contact or in any way affected by the mechanism. Every potential user will be interviewed periodically as the mechanism is incorporated into daily life. Questions ranging from how the mechanism performs to how the people view the task of unjamming will be asked. Advantages/disadvantages matrices will be updated and kept in order to analyze how the design, its uses, and its effectiveness might change as people EHFRPHPRUHDFFOLPDWHGWRLW2EVHUYDWLRQVFKURQLFOLQJGLIIHUHQWVQDSVKRWVRIWKHPHFKDQLVPVVWDWHDQGWKHXVHUVVDWLVIDFWLRQZLOODOVREHNHSWLQRUGHUWRDQDO\]HWKHFKDQJLQJUROHWKHPHFhanism might have. Careful, methodical observation will be crucial in pinpointing the absolutely critical small details that have the potential to greatly improve the design.

Conclusion

There are many factors like user habits, externalities, unforeseen obstacles, and unplanned adaptations of the design that all factor into what many times turns out to be a deceptively simple design. After taking Engineering Design and Communication, I have a solid grasp into what goes into designing a reliable, human-centered design. However, EDC does not allow proper assessment of a final prototype in the field. All successful designs undergo extensive user testing after the initial design is completed. This project presents an extremely valuable opportunity to extensively observe and evaluate a design in the field. It will allow me to observe the design in use and give me a sense of the broader impact of an effective design. It will also allow me to gain a deeper insight into the minute details of the design process. Not only will improvements to the current ram pump model benefit the village of Tres Hermanos as a result, but also thousands of systems all over the Philippines will benefit as well. In addition, other countries have recently become interested in this model as a solution to their water access needs, and so the completion of this project would allow all future manufactured models to accommodate the lever mechanism. The URG grant would be essential in making this possible.

Figure 1: The AIDFI Ram Pump utilizes a hinged waste valve door. The pump is shown here without the air tank and both drive and delivery lines.

Figure 2: The diagram above shows the entire system. The force of the water in the drive pipe flowing downhill causes the waste valve to close and pressure to build up in the body. This pressure increase causes the water to open the check valve to the air chamber where air pressure causes the valve to close again and water to be pumped out of the delivery line. While this is happening, the main drive pipe is relieved of the pressure caused by the initial closing of the waste valve. This in turn causes the waste valve to open, water to flow down the drive pipe, and the waste valve to close again due to the force of the flowing water. The cycle then repeats.