Clayton EO-100-1M, Инструкция по эксплуатации

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Clayton Steam Generator model EO-100-1M PAGE 22 / 70
Instruction Manual, doc.nr.: MAN18206 Rev A PSC
CONSERVATION OF GENERATORS
Generally two conservation methods can be distinguished. The first one is the dry shutdown method, the
second one is the wet shutdown.
6.6.1 DRY SHUT DOWN PROCEDURE
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With plant operating at normal steam pressure, close feedwater intake valve [26] , open separator drain
valve [32] and coil drain [25] valve and start timing.
•
Progressively close steam discharge valve in such a manner as steam pressure will remain just below
the modulation pressure. This will permit continuous burner operation. If coil thermocouple protection
does not shut down the boiler in 60 seconds, shut down plant manually after 60 seconds
•
Close valve in steam trap line and valve in automatic blowdown line.
•
When steam pressure drops to zero, close coil drain valve and steam discharge valve.
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Leave separator drain open but make sure that the drain line contains a vacuum break, so that no drain
water can be returned to boiler. If block and bleeder valves are installed in separator drain line, leave
bleeder valve open to aerate boiler.
•
To protect the whole installation from freezing, drain all water containing pipes and vessels. Drain
pumps, separators, hotwells and/or pressure vessels. Remove all tubes and equipment from water and
steam system in which a low sump may contain water. Remove snubbers from pumps and pig-tails
from pressure gauges. Drain blowdown tanks. See to it that no water can enter the system from drains.
If necessary create vacuum breaks on drain lines.
•
When restarting the installation and the boiler after long dry shutdown, adapt watertreatment in order
to rebuild protecting magnetite layer.
•
To restart, fill-up pressure vessels, hotwells, accumulators and/or separators with water. Circulate
water over boiler for two hours and purge all piping before applying heat to the boiler.
6.6.2 WET SHUT DOWN PROCEDURE
6.6.2.1 If feedwater tank is installed at top level of installation
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Bring system under steam pressure
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If the content of feedwater tank is not sufficient to fill up the system, raise water level before starting
this procedure or contact Clayton.
•
For longer shut down periods, bring oxygen scavenger level in feedwater tank up to 4 times normal
working level.
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Shut down burners.
•
Close drain valves and automatic blowdown valves
•
Close off supply water to feedwater tank.
•
Gradually close steam outlet valves (do not create overpressure)
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Fill system with water using feedpumps and/or circulation pumps.
•
Stop pumps.
•
Check oxygen scavenger level weekly. If oxygen scavenger level drops below normal working level,
add oxygen scavenger to feedwater and run feedpumps and/or circulation pumps for two hours.Check
water level in feedtank weekly. If level drops below minimum level add water and oxygen scavenger
to tank until normal scavenger level is established.
•
Whenever feedtank is refilled, check alkalinity . If needed bring alkalinity up to normal level while
running feedpumps.
•
Close off supply water to feedwater tank and check for leakages in system.