A metallurgical customer has a throughput requirement of 10 mbar l/s to 300 mbar l/s in a pressure range of 1x10-3 mbar to 0.1 mbar. The pump must be extremely reliable offering very high pumping speed and throughput, high cross-over pressure and must be industry proven. What pump does this customer want / need? Hint, the pump is a “secondary” vacuum pump (or high vacuum pump) and can be found in section 9 of the Edwards 2007 product catalog. Once you determine what pump the customer wants / needs, size the mechanical pump required to “back” the chosen secondary pump.
Hint, the pump is a “secondary” vacuum pump (or high vacuum pump) and can be found in section 9 of the Edwards 2007 product catalog. Once you determine what pump the customer wants / needs, size the mechanical pump required to “back” the chosen secondary pump.
Bonus question: How many EH4200 roots blowers does it take to match the throughput of the secondary pump required for this application?
Solution:
The pump referred to above is a 30B5M Vapor Booster Pump. This vacuum pump has the following features and benefits:
- Very large pumping speed at high operating pressures
- Very high throughput operation pressures (300 mbar l/s)
- Quick crossover for excellent pump down times
- Industry Proven for 40 years and continuously updated to suite OEM and end-user requirements
- Excellent Reliability
- Boiler access at both ends for ease of cleaning
All this from a pump that has no moving parts! Awesome!
We use the following equation to size a rotary mechanical pump to back the 30B5M Vapor Booster Pump
Where:
S = is the speed of the rotary pump
Tm= is the maximum throughput of the vapor pump (300 mbar l/s)
Pcb= is the critical backing pressure of the vapor pump. (5.3 mbar)
Substitute:
S = 113 l/s = 407 m3/hr = 240 ft3/min
The actual recommended backing pump is a GV400 Dry Pump, 412J Rotary Piston Pump or E1M275 Single State Rotary Vane Pump. These are given for guidance, please contact Edwards for a recommendation of pump combinations best suited for your application.
Bonus Question Solution:
3.5 x EH4200 mechanical blowers for operation at 0.1 mbar inlet pressure to the 30B5M.
5.8 x EH4200 mechanical blower for operation at 0.06 mbar inlet pressure to the 30B5M |
