Oil Sealed Vacuum Pump System

The company says their VmaxVFD, a liquid ring oil sealed vacuum pump system, is now available with a variable frequency drive, a VFD.
The system produces vacuum on a CNC router to hold workpieces that can be held better by vacuum than by magnetic or clamp down methods. The vacuum holds these pieces on the router tool table. This applies to materials such as wood, plastic, aluminum, stainless steel, brass, stone and other non-magnetic materials that require machining such as routing, engraving, milling, drilling and polishing. When using a vacuum, the workpieces to be machined can be held down without damage or distortion. 
The company says variable speed technology allows equipment to respond more precisely to different loads, and varies motor speed to match changing machine and usage requirements. The VFD controls the system’s capacity and automatically controls the desired suction pressure whether the router is working on a large 8' × 10' sheet of wood or on smaller pieces. By operating at as low as half the hp, the company says the user can see energy savings, often as early as the next utility bill. 
The system begins operation with a soft start that eliminates the amperage spikes associated with across the line starters. The utility companies bill at peak amperage usage and the number of times those peak levels are reached. The company says the VFD reduces the peak amperage numbers, which results in less overall energy costs. For shops running in a continuous, 24-hour shift setting, users will benefit from overall energy savings and longer operational life of the pump. When running constantly, the machine will have less start-up and stop time (the motor slows down when demand is low and the overall amperage is lowered). The VFD is said to provide up to a 50 percent turn down in power thus equating to similar energy savings. For example, a 40 hp pump will run at 20 hp with the VFD, but still provide the same vacuum level required. Without the VFD, a loss of system efficiency can usually be expected for most of the operation cycle. 
A common concern with CNC router users is part slippage due to insufficient flow or vacuum. The system addresses this concern with several additional user benefits. By providing a consistent vacuum level and operating at approximately half the hp, the company says a reduction in part scrap rates and material damage can be seen by the router user. Because of the reduced energy consumption, immediate cost savings are realized. Also, with its conservative speed, the system has a quiet operation, below 70-80 dBA depending on the pump size. The company says the VFDs are easy to install and are one of the most cost-effective ways to maximize efficiency and reduce operating costs. The system is available in 35-5,000 cfm.