CleaverBrooks CBEX Elite, Эксплуатация и обслуживание

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Waterside Care
3-2 750-368
CBEX Elite 100-1200 HP
FIGURE 3-1.
Dip Tube
The air vent tapping on the top center line of the boiler should be piped into the expansion or compression tank.
Air trapped at the top of the boiler will find its way out of the boiler through the tapping.
Minimum Water Temperature
The minimum recommended boiler water temperature is 170º F. When water temperatures lower than 170º F
are used, the combustion gases are reduced in temperature to a point where water vapor condenses, which can
cause corrosion in the boiler and stack.
Condensation is more severe on a unit that operates intermittently and which is greatly oversized for the actual
load. Condensation can be minimized by maintaining boiler water temperatures above 170º F.
Rapid Replacement of Boiler Water
The system layout and controls should be arranged to prevent the possibility of pumping large quantities of cold
water into a hot boiler, which will cause shock or thermal stresses. Water temperature in a boiler of 200° F or
240° F cannot be completely replaced with 80° F water in a few minutes time without causing thermal stress.
The same fact applies to periods of normal operation, as well as during initial startup.
When individual zone circulating pumps are used, it is recommended that they be kept running-even though the
heat users do not require hot water. The relief device or bypass valve will thus allow continuous circulation
through the boiler and can help prevent rapid replacement of boiler water with cold zone water.
Continuous Flow Through the Boiler
The system should be piped and the controls arranged to allow water circulation through the boiler under all
operating conditions. The operation of three-way valves and system controls should be checked to be sure that
the boiler will not be by-passed. Constant circulation through the boiler mitigates the possibility of stratification
within the boiler and results in more even water temperatures to the system.
A rule of thumb of 3/4 to 1 gpm per boiler horsepower can be used to determine the minimum continuous flow
rate through the boiler under all operating conditions. The operator should determine that water flow exists
through the boiler before initial firing or refiring after boiler has been drained.
NOTE: If the operating water temperature going to the system must be lower than 170º F, the operating boiler water
temperature should be a minimum of 170º F and mixing valves should be used to avoid damage to the equipment.