ITT Goulds Pumps 3500XD, Инструкции по установке, эксплуатации и обслуживанию

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Figure 19: Vent line to drain
5.3 Dilution system – typical
(Refer to Figure 17 and 18)
For Order Specific Description - Refer to the IOM Appendix
An automatic standpipe dilution system is recommended so the highest possible average consistency for
which the discharge piping is designed can be continuously delivered by the pump. The consistency of
the stock being pumped is the major contributor to friction head loss in the discharge piping, followed by
temperature and pH (this is true only if the same fiber type is being pumped). The higher the consistency,
the greater the friction head loss will be. Usually the only parameter or variable that can be adjusted in
the standpipe is stock consistency, which can be controlled by the dilution system.
The dilution system normally consists of an upper spray nozzle with a control valve (DCV-1) and a lower
dilution header with a control valve (DCV-2)
In the auto mode, the upper dilution valve (DCV-1) will open to assist pumping when the standpipe level
exceeds its set point by 10%. A maximum signal selector is also used to allow DCV-1 and DCV-2 to be
open a preset amount, while still maintaining the automatic function on an increase in level.
The normal set point of the standpipe level controller (LCI) is approximately 25%. When the level ex-
ceeds 25%, the level control valve opens to bring the level back to its set-point. When the level exceeds
35%, the dilution controller (DCI) will signal the dilution valve (DCV-1) to start to open. It will open gradu-
ally with level and be 100% open at 85% level. DCV-1 will gradually close as the level decreases back to
its set-point.
The lower dilution valve (DCV-2) should be programmed to begin opening when DCV-1 is greater than
50% open, and should be 100% open, when DCV-1 is 100% open. Refer to the IOM Appendix for the
order specific information on the dilution scheme.
If the Model 3500XD is running and the standpipe level is less than 10%, the upper and lower dilution
valves will open 100%. The valves will close when one of the above conditions change.
5.3 Dilution system – typical
28 3500XD Installation, Operation and Maintenance Instructions