BMEIA Hydram Pump DesignWCDE-00088-06Air Vessel Volume CalculationThe air vessel is a vital component of the Hydram pump and is visually its main characteristic. Without it, thewater coming through the delivery valve would have a great velocity and too much head losses would becreated. With the air vessel, the water is slowed down because the air inside the air vessel acts like a spring.The volume of the air vessel, manufactured by BMEIA, ranges between 0.5 m3and 2 m3depending on thewater source and water requirements. The air vessel is axially symmetric about the vertical axis, as shown inFigure 2 (b). The top section is an elliptical sphere with a flange and the bottom section is a cylinder withamounted connecting parts. Figure 2 (a) and (b) shows a section view of the air vessel and the approximatedinside profile respectively. The basic design parameter used to determine the inside volume is shown in Figure2 (b) and detail dimension of the air vessel is given in Appendix A.The inside volume of air vessel needs to be estimated during the preliminary design stage since it determinesthe amount of water that can be pumped per unit time. BMEIA engineers used CAD software to compute thevolume and amount of material required as part of their design process. After developing the 3D model aMass Properties dialog box, similar to Appendix B, displays all geometric details of the given 3D model,including its volume. However, this method is a time consuming process since the designer needs to develop aCAD model to determine these parameters. In the following exercise calculate the volume of the air vesselshown in Fig. 2 using a triple integral in circular cylinder coordinates evaluated using MathCAD. Compareyour results with the value from the SolidWorks® model shown in Appendix B.esten(a) (b)Figure 2:- Hydram pump air vessel (a) section view (b) inverted air vessel inside profile and design parameters
BMEIA Hydram Pump DesignWCDE-00088-06References David Effa and Dr. Abiy Awoke, “BMEIA Hydram Pump Design”, WCDE 00089-01, Waterloo Cases inDesign Engineering, April 2010 David Effa and Dr. Abiy Awoke, “BMEIA Hydram Pump Design”, WCDE 00089-02, Waterloo Cases inDesign Engineering, April 2010 Lorenz, H.: Theorie des hydraulischen Widders. Z. VDI Vol. 54 (1910) pp. 88/90.
4WCDE-00088-06Appendix A - Air Vessel Detail Design
5WCDE-00088-06 BMEIA HYDRAM WATER PUMP DESIGNAppendix B - SolidWork Air Vessel 3D model Mass Properties Dialog Box