Vacuum Pump Water Priming Systems
The Duplex, tank mounted system is fabricated and tested in accordance with CompreVac guidelines for industrial vacuum systems. The System includes two single stage, rotary vane, air cooled, vacuum pumps. The lubricated vanes are manufactured from aluminum a minimum lifetime expectancy of 50,000 hours and supported with a 5 year warranty.
Each pump is expected to operate at a vacuum depth in excess of 20 inches Hg vacuum and preferably at 29 inches Hg. The duplex system is mounted on an ASME coded receiver with CRN number, application specific controls, all necessary instrumentation, interconnecting piping and wiring.
The system is configured for easy installation with all electrical connections terminating at one location (starter panel) and having one vacuum (inlet) connection. Each pump has its own discharge port, which is an NPT connection.
An Electronic Control Panel designed and built by CompreVac Electronic Engineers is the most usual preference. This option provides for an Automated Solenoid Operated Drain System that is able to evacuate any water that finds its way back to the Central Vacuum Receiver Vessel automatically, even while the system is under full vacuum.
In addition, purge valves are located ahead of each pump to ensure that vapors are driven off prior to pump shut-down. Minimum run timers and temperature switches safeguard the longevity of the motors and pumps.
Many plants have experienced Float Valve failure where water under full pressure can be slammed into the Vacuum Priming System. CompreVac have an additional safeguard for this eventuality that involves the isolation the vacuum Priming System within one second should the emergency arise. Visual and audible alarm systems, also SCADA connections provide plant operators with full remote control.
CompreVac - Pioneers
Our engineers have pioneered the use of Oil Lubricated Rotary Vane Pumps for water pump priming over the past 10 years and have reached a stage where we can be confident that they will perform beyond expectations. In the past, it was easy to identify the vacuum priming system in a water pumping station because it was usually the ugliest, most rust stained piece of equipment in the plant. Refer to the above before and after shots.
Water pumping stations use large centrifugal impeller pumps to pump the water into the plant for purification before it gets sent into the grid. These large, electric driven pumps are unable to prime themselves. Quite often, they are required to pump water from a lower level, (lake or river). This means that there is a large diameter 12”, 22”, 36” pipe that rises up from the lower level lake or river and it is totally empty. At the highest point of the impeller pump is a special float valve. (Please refer to Vacuum Priming Valve on right) . The priming valve from the pump(s) has a 3/8” pipe that runs back to the vacuum pump system and is constantly under a vacuum which is in excess of 15”Hg. The deeper the vacuum, the higher the system can raise the water up the pipe and fill the water impeller pump so that it can be started. Sometimes there are situations where the plant needs to start up a pump (or several) in an emergency. Therefore it is a great advantage to have a vacuum pump priming system that is has a deep vacuum and fast pumping speed, (more cfm).
Most existing water pumping stations have Liquid Ring Duplex Vacuum Pumping systems like the one in the BEFORE picture above which we can provide if the end user is insistent. However, these systems require water to seal them, they are prone to corrosion and they require continuous ongoing maintenance due to water leakage. The pumping speed is often slow, as they seldom achieve a good vacuum depth. This also changes as the seasons change and water and ambient temperatures fluctuate. Reliability is the greatest reason for dissatisfaction with these systems.