Design of a miniature pump

• Main Author: Tan, Tat Cheng.
• Other Authors: Chan Weng Kong
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Mechanical engineering::Fluid mechanics
• Online Access: http://hdl.handle.net/10356/54011
• Institution: Nanyang Technological University

Macro size pumps do have their limitations which constricts the number of applications it could serve. On the other hand, the miniature pump opens up a new area of applications as it brought about mobility, precision flow rate, convenience and etc. Design and development of the miniature pump is necessary in serving these applications, however, miniaturization is a very challenging process. In this project, a new concept for a miniature pump design was designed and developed. The novel reciprocating pump design features a contactless energy input mechanism through the use of permanent magnets. The new reciprocating wing pump (RWP) is unique in that it does not require any additional valve to regulate flow and produces unidirectional flow. In addition, the design is simple and easy to fabricate. The risk of contamination is kept to a minimal without the use of supporting components such as bearings. A test rig has been made for the experimental study. The prototype of the pump was subjected to experimental testing at three different speeds (100rpm, 150rpm and 200rpm) along with variables to determine the pump performance and characteristics. Variables such as different materials of flat valve (acrylic, aluminium and stainless steel), different rotation angle (30 and 40 degrees) and also varying stroke length (40mm, 50mm and 60mm) were introduced. The final RWP is 27 mm long, has a diameter of 18.8 mm and is mainly made of magnetic stainless steel. Instantaneous differential pressure and instantaneous flow rate measurements were taken in the experimental study. The results show that RWP generates flow even during its backward stroke which verified the unique characteristics of the RWP. This proves that the RWP is superior to the conventional reciprocating pump. The average flow rate as high as 5 l/min was achieved when the pump operates at 200 rpm with a stroke length of 60 mm. The RWP also achieve flow efficiency as high as 167% when comparison between theoretical calculations of conventional reciprocating pumps and experimental results of the RWP was made. Overall, the pump shows reliability as denoted by consistent readings at every cycle, similar to the performance of a positive displacement pump. However, the RW is able to achieve higher flow output and has a simplistic design which reduces the difficulty of miniaturization.