Our team primarily used Ansys Granta Edupack to select materials. Using the level 3 dataset, we filtered materials by operating temperature and acid resistance (The level 3 dataset allows filtering by specific acids at varying concentrations). We then produced an Ashby chart showing acid resistance vs bulk price to determine which materials would be most suitable without driving the price up unnecessarily. 

Shell

The main body of the pump was composed of sheet molding compound, which was to be compression molded and machined.

The first change we made from the original design was to adjust the location of the inlet and outlet ports. In the original design, the angle between the ports was smaller than the vane angle, which allowed for fluid to bypass the pump.

We also chose to shape the main housing as a ‘pie dish’ in order to reduce part count and eliminate a location where a seal would be necessary.

Faceplate

We chose to enclose the ‘pie dish’ with water-jetted soda-lime glass, as this provided ease of viewing for preventative maintenance. 

In order to have the level of acid resistance necessary, the rotor body was made from Alloy 20, a Nickel stainless steel alloy. To achieve the desired geometry, it was to be forged and turned.

The main change we made from the original rotor design was to increase the number of vanes and offset them from the radius. The offset essentially made the pressure differential inside the chamber an ally, as it forced the vanes outward as the rotor spun.

The rotor was mounted on a 316 Stainless Steel keyed shaft to allow for easier maintenance.

The vanes were designed as injection-molded PTFE (e.g. Teflon). The edges were rounded to allow for a tangent contact with the housing. In order to account for loading, we modeled the vanes as a cantilevered beam loaded with the inlet and outlet pressures.