A design synthesis for a microflow control system is presented based on the interrogation of an analytical model, testing, and observation. The key issues relating to controlling a microflow using a variable geometry flow channel are explored through the implementation and testing of open and closed-loop control systems. The reliance of closed-loop systems on accurate flow measurement and the need for an open-loop strategy are covered. A valve and control system capable of accurately controlling flowrates between 0.09 and 400 ml/h and with a range of 900:1 is demonstrated.
OhK. W.AhnC. H.A review of microvalves. J. Micromech. Microengng, 2006, 16(5), 13–39.
2.
LaserD. J.SantiagoJ. G.A review of micro-pumps. J. Micromech. Microengng, 2004, 14(6), 35–64.
3.
KiddM. D.Bicycle chain efficiency. PhD Thesis, Department of Mechanical and Chemical Engineering, Heriot-Watt University, Edinburgh, UK, 2000.
4.
StilesG. F.Liquid viscosity effects on control valve sizing, 19th Annual Symposium on Instrumentation for the Process Industries, Texas, 1964.
5.
BaumannH. D.Viscosity flow correction for small control valve trim. Trans. ASME, J. Fluids Engng, 1991, 113(1), 86–89.
6.
GeorgeJ. A.Sizing and selection of low flow control valves. InTech, 1989, 36(11), 46–48.
7.
RahmeyerW.DriskellL.Control valve flow coefficients. J. Transp. Engng, 1985, 111(4), 358–364.
8.
SondhH. S.SinghS. N.SeshadriV.GandhiB. K.Design and development of variable area orifice meter. Flow Meas. Instrum., 2002, 13(3), 69–73.
9.
SinghS. N.GandhiB. K.SeshadriV.ChauhanV. S.Design of a bluff body for development of variable area orifice-meter. Flow Meas. Instrum., 2004, 15(2), 97–103.
10.
ThananchaiL.Design factors for ‘linear’ ball valve: theoretical and experimental studies. Songk-lanakarin J. Sci. Technol., 2005, 27(2), 353–361.
