A New Solution of Spiral Chambers and Aspiration Elbows of Welded Double Shells for Pumps, Provided by Mathematical Modeling

摘要

Spiral chambers and aspiration elbows with oval section for pumps can be manufactured by casting and of welded shells. In the latter case result lighter assemblies and are obtained better yields due to lower roughness. Each shell represents a developable surface. If the shells are made of usual cheap sheet metal, result assemblies that wear out quickly, especially by pumping abrasive and / or corrosive liquids. If the shells are made of abrasion and/or corrosion resistant metal sheet, than the assemblies are expensive and weld difficult. Accurate calculations can provide both an easy implementation and a new solution, adopting double shell. To eliminate these disadvantages propose a new solution, based on double shells, providing both a relatively low cost price, and, especially, obtaining and maintaining long yields higher including in pumping abrasive and / or corrosive liquids. Thus each dual shells has outer shell of usual sheet metal, cheap and easy to weld, which takes all the pressure generated mechanical stress calculation and inside has a thin shell of abrasion and / or corrosion resistant metal sheet, which ensure achieving and maintaining high yields, resisting to wear. Realization of this solution requires a complex mathematical modeling, in particular to ensure correct folding. The paper presents mathematical modeling that will be used to the practical realization of the new technical solution of double welded shells for spiral chambers and for aspiration elbows with oval section of hydraulic machines.