Grantee Research Project Results
2022 Progress Report: AguaClara's Ram Pump for Zero Electricity Drinking Water Treatment
EPA Grant Number: SV840017Title: AguaClara's Ram Pump for Zero Electricity Drinking Water Treatment
Investigators: Cowen, Todd
Institution: Cornell University
EPA Project Officer: Aja, Hayley
Phase: II
Project Period: August 1, 2020 through July 31, 2022 (Extended to July 31, 2023)
Project Period Covered by this Report: July 1, 2021 through June 30,2022
Project Amount: $75,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2019) Recipients Lists
Research Category: P3 Awards
Objective:
The fundamental purpose of the ram pump is to relieve the burden of labor on the plant operators who are currently manually filling buckets of filtered water to deliver to AguaClara Plant’s chemical stock tank. The ram pump, in turn, will automatically pump this water into the chemical stock tanks and become integrated into the plant's functionality. Our research during the past year supports this end-goal and the mission of AguaClara in general.
Progress Summary:
During this performance period the work focused on an experimental approach to better understand the role of springs and spring constants with regard to the opening and closing of the ram pump check valve, with a focus on simplicity and translatability to field scale AguaClara plants. Robustness of design and construction of ram pump components was foremost in our minds as well as the ability of plant operators in the field to calibrate and operate the pump without the requirement of any technical equipment.
At the start of the performance period, various components of the laboratory model required replacement and the first step was to replace these components. While waiting for replacement parts to arrive we formulated and started work toward answering a new question, what is the effect of driving pressure head at a given plant on ram pump performance and robust calibration and configuration? We identified the key parameters but decided this should be a new applied research project in the future as answering the question would require significant reworking of our existing physical model, which would delay meeting current objectives. In restoring our laboratory model ram pump to fully functional form we realized that only three subteam members understood the ram pump operation sufficiently well to troubleshoot the facility. This was deemed a problem, both in the lab and the field, and we developed a concise reference manual to allow the easy dissemination of gained ram pump knowledge to new operators.
Our experimental; program showcases the efficiency and reliability of the work process in the ram pump development team and AguaClara in general. Previous work and results are the foundation to new ideas and innovation. For example, previous work had centered on a parallel spring model that included a weak and strong spring to control the opening and closing of the ram pump check valve. In this performance period, the subteam decided to focus on simplicity and robustness. They revisited the value of the dual-spring configuration, finding that the weak 2 spring contributed little toward performance but added complexity and made the decision to eliminate the weak spring. The subteam then turned its attention to fully characterizing the range of single strong spring constants that met the design criteria of delivering the requisite flow rate against the minimum driving hydrostatic head of 5 m. On a broader scale beyond the Cornell University laboratory and ram pump prototype, the determined optimal spring constant range will allow ram pump implementation in ram pumps across all AguaClara plants, each with its own driving pressure head. Simplicity in optimizing and calibrating the system eases the process for plant operators and again, prevents the stoppage or a inconsistent flow delivery of clean, accessible water.
Future Activities:
The final task carried out during this 12-month period was to theoretically estimate the time for check valve closure, which was estimated based on fundamental fluid mechanics and Newton’s second law to be 83 ms. With this value in hand, in the next and final performance period the subteam will collect images of the spring/valve assembly at > 50 frames per second and use quantitative image analysis to determine if the valve, once the drive pipe is full of water, is re-opening to the initial position or if the force of the water is too great for the spring to fully re-open the valve to its original position. We will also compare our results to the determined theoretical closing time of 38 ms to evaluate if our theoretical model of the valve movement is sufficiently accurate.
Progress and Final Reports:
Original AbstractP3 Phase I:
AguaClara's Ram Pump for Zero Electricity Drinking Water Treatment | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.