Water contamination is a serious problem for hydraulic and lubrication oils that can cause surface corrosion, reduced lubricity, and degradation of the oil's physical and chemical properties. The Active Flow Dehydrator (AFD) addresses moisture issues by producing a continuous flow of dry air into the system to desorb moisture from the oil. It uses pressure swing adsorption to attract water vapor more strongly than air, adsorbing moisture and producing dry air without moisture buildup. The AFD operates automatically to maintain low humidity levels in the oil.

1. Water contamination is one of the most common problems in the management of hydraulic and lubrication oil,
and one of the most serious. Very small amounts of water can cause:
• Surface corrosion of the lubricated parts & accelerated metal surface fatigue wear
• Physical property degradation of the oil, such as reduced lubricity and load carrying characteristics
• The chemical properties on which even small amounts of water can have a measurable effect are:
Thermo-oxidative stability - the reaction of oxygen with fluid basestock forms oxygenated compounds
and is accelerated by heat and the presence of water. Metals, in the form of wear debris, often act as a
catalyst. Oxidation ultimately leads to higher viscosity and deposits, such as polymeric compounds or
sludges.
Deposition characteristics - soot, coking.
Premature additive depletion and additive precipitation, impacting fluid performance.
Hydrolysis: - the decomposition of ester-based fluids as a result of heat and water results in acids and
alcohols, leading to increased corrosivity.
The Active Flow Dehydrator (AFD)
was developed by J.M. Grimstad, Inc.
to address moisture and humidity
problems that exist in many gear
boxes and hydraulic systems. AFD
produces actively flowing dry air into
the head space of the system forcing
the desorption of moisture from oil.
AFD
Active Flow Dehydrator
J.M. Grimstad, Inc.
Muskego, WI. PH: 414-422-2300
www.grimstad.com
An Employee Owned Company

2. Features:
As the surface of the oil in the reservoir or gear box is continuously flushed with dry air, moisture
is removed, and the oil dries to beneficially low levels.
Actively flowing dry air into the tank head space prevents build up of moisture.
Once the oil humidity levels are in control, the system operates in a monitor mode, operating as
needed to maintain dry oil.
• Simple, low maintenance design
• Long service life
• Small size: 20 inch cube
• Easy to install on existing systems in under
30 minutes
• Automated control with error monitoring
• Operates as a stand alone system or easily
integrates with PLC’s and monitoring systems
• Real-time moisture monitoring with relative
humidity and temperature
• Standard voltage: 115V/60hz or 230V/60hz
single phase AC
• 12VDC available
• Robust powder coated frame
AFD
Active Flow Dehydrator

3. The AFD is a Pressure Swing Adsorption device. Pressure Swing Adsorption is a
technology utilized to separate certain gas species from a mixture of gases under
pressure.
Pressure Swing Adsorption relies on the fact that under pressure, gases tend to be
attracted to solid surfaces, or adsorbed. The higher the pressure the more gas is
adsorbed. When pressure is reduced, the gas is released or desorbed.
When pressurized air is passed through the AFD, the dryer system attracts water vapor
more strongly than air, adsorbing moisture and producing an active flow of dry air. The
dryer utilizes twin desiccant beds that operate under 1% relative humidity allowing a
continuous flow of dry air.
How the AFD Makes Dry Air Continuously

4. AFD DEMO AND TEST SYSTEM

5. ---------Time--------
Added Water to oil

6. AFD Maintenance / Replacement Parts
The AFD, under normal service will have long service life.
The compressor is rated for 15,000 hours of continuous use prior to replacement
of piston cup seals. This simple process requires removing four bolts on the
compressor head, removing the old seal and replacing with the new cup. The
compressor carries a 5 year warranty.
The dryer portion utilizes 2 desiccant cartridges with a life span of 12,000 hours.
The cartridge kits include seals and built in filters.
The dryer also has a valve pack replacement kit. This kit should be replaced at
24,000 hours of use or at the second desiccant replacement period. The AFD
automatically informs the user when the desiccant needs to be replaced by hours
of use.
J.M. Grimstad, Inc.
Muskego, WI. PH: 414-422-2300
www.grimstad.com
An Employee Owned Company