Fluid purification is an essential task at hydroelectric dams. Water, entrained air and gases and solid particulates often contaminate turbine oil and hydraulic fluid and must be removed on a regular basis.
Conventional purifiers cannot start removing water until the hydraulic reservoir fluid reaches and maintains a temperature of 150 degrees F. This can take hours if the ambient temperature is low and the reservoir volume is large, which slows down operations and drives up energy costs.
This problem can be eliminated with Parker’s SentinelTM fluid purification system, which removes water and other contaminants from hydraulic fluid more efficiently, at less cost.
The Sentinel treats contaminated hydraulic fluid in smaller volumes. Every two minutes a 6KW heater heats 4-5-gallon batches of fluid at a time, cleans the fluid, and then releases it. This conserves power and saves time that would otherwise be spent heating the entire main system reservoir to the required temperature.
Other advantages include:
- Optimized size, weight and design for 1,000 gallon oil reservoirs
- Up to 75 percent lighter and smaller than most traditional full-scale purifiers on the market
- Easy to place, position and move due to smaller overall footprint
- Can be automated with customer-selected parameters within IQAN interface
How it works
Contaminated fluid is drawn through the Sentinel circuit by vacuum. The fluid is subjected to optimum vacuum, temperature and surface area to reduce the boiling point of water, and convert water to water vapor. Optimum temperature is achieved with a low watt-density heater. Maximum surface area is accomplished by passing the fluid through a unique diffusing column.
The fluid is protected from excessive heat by circulating it for a fixed amount of time. When that preset time period has ended, the fluid discharges through a high-efficiency filtration system to the main system reservoir. Any water vapor extracted from the system is exposed to a series of coalescers to eliminate any carryover oil vapor in the exhaust stream. The process repeats until the desired steady state condition is achieved.
The Sentinel is the only purifier on the market with an automatic monitoring system. A Parker IQAN controller allows the operator to set the parameters of operation. Once the parameters are set and the unit is turned on, it operates until the low limit of water content has been attained. At this point the timing setting takes over. The timer can be set from 1 hour up to 720 hours. Once the time setting is reached, the unit turns on, pulls a sample of fluid into it and measures the water content. If the content is below the high setting, the unit goes back to the timing mode. If the water is at or above the high setting for water, the unit goes back into operation and runs until it reaches the low setting again and repeats. The Sentinel can also be operated in standard mode—once the parameters are set and the unit starts, it will run until it reaches the low water setting and then turns off. It will not come back on unless the operator restarts the unit.
By keeping the hydraulic system as dry as possible, the Sentinel lessens the chance of destroying a bearing on a turbine and losing millions in revenue as a result of lost time and turbine repair. The unit can also diagnose almost any possible problem as it arises, showing an alarm on the screen; if it is a serious situation, the unit shuts off automatically to prevent any damage.
Attending Power-Gen International?
Garry Moore, Hydraulic Filter Division Parker Hannifin
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