Clayton Steam Generator model EO-100-1
PAGE 50 / 70
Instruction Manual, doc.nr.: MAN18206 Rev A PSC
THE CLAYTON COIL
The coil of a Clayton Steam Generator is of a unique design which has been developed for optimum heat
transfer at all steam output levels.
The coil is a single water tube which is stacked in spirally wound layers in the upper section of the
Clayton Steam Generator and forms a ‘water wall’ around the combustion chamber of
the lower section. The configuration of the coil as well as the variation in the tube
diameter, spacing between layers and spacing between tube turns in different
temperature zones of the coil are all carefully designed to maximise efficiency and
thereby minimising fuel consumption.
The spiral construction of the coil is extremely robust and counteracts the effects of expansion during rapid
heating and cooling cycles. The coil also undergoes in-house heat treatment to eliminate stresses and each
coil is tested at high pressure.
An added advantage of the single coil design is that the internal condition can be monitored by observing the
pressure of the feedwater at the coil inlet. In the case of oil fired units, sootblowing facilities are provided to
remove deposits from the outside of the coil.
It is recommended to open the soot blower valve once every 8 hours of operation, for a period as described in
( 9.2.2. ).
Soot is removed by blowing full capacity of the steam generator into the combustion chamber through
connection
(4-fig.8.8).
9.2.1
REMOVAL OF SCALE FROM RESTRICTED HEATING COIL ( FIG 8.8 )
-An authorized Clayton technician should supervise this operation
•
Obtain a 200 l container
(heat resistant, not galvanized)
and place it near the feedwaterpump. If
possible provide a pipe outlet DN 50 at 50 mm above the bottom of the container for acid suction.
Elevate the container to provide about 30cm gravity feed to the feedwaterpump.
•
Close steam discharge valve
[47]
•
Start unit without burner operation and circulate cold water until entire system is cooled. Then stop
plant and drain hotwell.
•
Remove intake pipe and attach a suction hose
(heat and acid resistant).
Attach other end of suction
hose to outlet at bottom of container. If an outlet is not provided in the bottom of the container, fasten
a fine mesh screen over end of hose and place the end of the hose in the tank. Place about 20 cm of
water into the tank. Be sure suction hose or suction outlet is below the water level.
•
Attach hose to separator drain valve
[32],
long enough to reach the 200 l container. Securely tie or
fasten the end of the hose to the container so that it will not be dislodged during the cleaning
operation. Considerable pressure is sometimes developed in the hose due to acid reaction with scale.
•
Close steam trap valve
[35].
•
Start plant without burner operation. Add or remove water from the container until a steady
circulation can be maintained trough unit and back to container with about 13 cm of water above
suction outlet remaining in container. Be sure feedwater pump housing is primed.
•
Mix a can KLEENKOIL with 4 litres of hydrochlorid acid and slowly add this solution to the water in
the container. If necessary prepare more solution
