MTS Water Quality Guide - Manual (Page 20)

Heat Exchanger Care and Water Quality Guide 20 Heat Exchanger Care
5. Keep the motor outside surface of direct drive heat exchangers free of dirt
and grease so the motor will cool properly. Make sure the cooling air over
the motor is not obstructed. Pre lubricated ball bearing motors require no
lubrication for extended periods of time. Follow the lubrication instructions
attached to the motor and provided by the motor manufacturer.
6. The combination fan hub and sheave assembly on external drive heat
exchangers is pre lubricated at the factory prior to shipment. Lubricate the
assembly after every 1000 hours of operation following the manufacturer's
instructions.
How do I remove corrosion?
MTS recommends you use Dowfrost HD, an industrially inhibited propylene
glycol fluid to remove corrosion from the tubes and protect them from future
corrosive attack.
1. Clean new or lightly corroded existing systems with a 1–2% solution of
trisodium phosphate in water prior to the installation of the Dowfrost HD.
2. Extensively corroded systems should be cleaned by an industrial cleaning
company and all necessary replacements and repairs should be made before
the heat exchanger is used again.
How do I remove water from the hydraulic fluid after a heat exchanger failure?
Once a heat exchanger failure occurs, remove the damaged unit from service and
assess the amount of water in the hydraulic fluid. If the contamination is severe
(the water content is greater than 2.0% by weight), the sensible approach may be
to drain and discard the hydraulic fluid in the distribution system. If discarding
the contaminated fluid is not desirable of feasible, the hydraulic fluid can be left
standing and a large portion of the water will separate out. This water can then be
siphoned from the bottom of the reservoir. Water absorbing filter elements can be
used in the HPU to remove most of the water from the hydraulic fluid.
The hydraulic distribution system also requires attention after a heat exchanger
failure. Water will tend to settle in low points in the system. These points should
be drained and the fluid discarded. If contamination is not severe (water content
is less than 1.0% by weight), it may be advisable to simply flush the system with
the “dry” fluid from the HPU, and continue dry filtering the water.
How do I know when to replace my heat exchanger?
Watch for changes and trends in your regular analysis of the hydraulic fluid (for
example, the copper counts in the hydraulic fluid may rise with each analysis). A
slow trend is nothing to worry about, but a sudden change in the fluid analysis
may indicate that your heat exchanger will fail soon.