Water Contamination In Hydraulic Oil

Portable Purification Systems Solve Contamination Problems in Power Plants

Hydraulic oil or hydraulic fluid is the mechanism for transferring power in hydropower systems. These fluids can be water or oil-based. In order for these power systems to function properly, the system must be free of contaminants.

Water is one of the most common contaminants in a fluid power system and one of the most damaging. When water contaminates a system, it can cause serious problems. Among the most serious problems are:

  • Fluid breakdown
  • Reduction of lubricating properties
  • Additive precipitation
  • Oil oxidation
  • Abrasive wear
  • Corrosion

There are a variety of so-called dryers that attempt to address the water contamination issue. A centrifuge unit can remove water. However, there are some drawbacks. These include it only removes free water, has difficulty breaking stable emulsions, and is costly. Another type of dryer is a desiccant unit. Unfortunately, they have limited water removal capability, they only remove air ingressed particles, and again, can be costly. A third option is a coalescent unit. Which can only remove free water, has difficulty breaking down stable emulsions and can take up a lot of floor space.

Free vs. Dissolved Water

When discussing the effects of water contamination, there are two kinds of water to consider. The first is so-called “free” water and the second is “dissolved.” Free water occurs when oil becomes saturated and cannot hold any more water. This water is usually seen as cloudy oil or puddles of water at the bottom of an oil reservoir. Water which is absorbed into the oil is called dissolved water. At higher temperatures, oil has the ability to hold more water in the dissolved stage due to the expansion of oil molecules. As the oil cools, this ability reverses and free water will appear where not visible before. In addition to temperature, fluid type also determines the saturation point for each system.

Restoring Contaminated Hydraulic Oil

With the use of a portable purification system from Parker, it’s possible to restore the oil to acceptable levels of purity. The machine draws the contaminated oil via a vacuum. The oil passes through the in-line low watt density heater. The heater raises the oil’s temperature an optimal 150°F. The oil then enters the distillation column where it is exposed to the vacuum through the use of special dispersal elements.

This process increases the exposed surface area of the oil and converts the water to vapor form. The vapor form is then drawn through the condenser by the vacuum pump. The water-free oil falls to the bottom of the column and is removed by a heavy duty lube oil pump. This pump forces the dry oil through a final particulate removal filter. Clean oil passes out of the unit, back to the reservoir, and into the system. The oil is clean.

Parker Sentinel System

The Parker Sentinel System has many applications in the commercial/industrial marketplace. The most common applications in power plants are turbine oil, transformer oil and electro-hydraulic control systems. The system has many important design advantages:

  • Condensate holding tank to eliminate potential hazard of exhausting in the atmosphere
  • Compact size allows for easy transport and movement around the plant 
  • Automatic operation increases running time and reduces labor costs 
  • High temperature safety circuit prevents system damage 
  • Programmable thermostat allows for unattended operation and increases oil life