JOURNAL O F CHEMICAL EDUCATION
A SIMPLE GAS-MIXER PUMP W. T. M. JOHNSON E. I. du Pont de Nemours & Company, Philadelphia, Pennsylvania
A SIMPLE gas-mixer pump was required for studies involving gas and vapor evolution in static reactor syst e m s . b k magnetically driven gas pump was developed featuring simple construction, operation, and servicing. The essential features of this pump and some performance data are aiven in the hope that other workers may find this type of pump nsefnl.
t
,,,,,,,IN GAS WASE
0 TEFLON PLUG,
I/
11
IMPELLER ASSEMBLY
20 TIME
40
6
- MINUTES
Fiqure 2. Gas-pump Porformanco Cu-s FAN IRON STRIP WATCH GLASS
ALUMINUM FAN
TEFLON PLUG WATCH GLASS
Sketches of the pump are shown in Figure 1; the glass-joint housing makes for simple replacement or adjustment. The drive unit is a rectangular iron strip curved to fit against the watch glass and sealed from the gas atmosphere by the base plate of the aluminum fan unit. The fan blades were cut from sheet aluminum and cemented to the aluminum base plate with a sodium silirate-iron oxide cement; this cement was used for the entire gas-impeller system. Some performance data are indicated in Figure 2. These data show the pumping behavior for a radioactive vapor admitted to a 130-ml., cyclic, static reactor system containing a Geiger-counter gas cell. An improved pump might be made from an impeller molded completely of "Teflon" tetrafluoroethylene resin containing. an embedded bar magnet.
