Level control in a horizontal cylindrical tank

[Yobbo]

L.S.,

I would like to check a certain feature with others about copntrolling a level in a horizontal cylindrical tank. I have been taught that for level control it is wise to have a certain dead zone around the nominally desired level, so that small deviations will not immediately require controlling action and that the tank will function more like a volume buffer.
Are there any considerations pro or against to actually stick to this rule?

Thanking you in advance for your comment I remain

with best regards,

Karel Postulart

Karel Postulart, The Netherlands
Nuon Power Generation

 

[xnuke]

It depends on the function of the tank. See

http://www.driedger.ca/ce6_v&t/CE6_V&T.html.

xnuke
"Live and act within the limit of your knowledge and keep expanding it to the limit of your life." Ayn Rand, Atlas Shrugged.
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[sreid]

The reason for the dead band is to minimize cycling of the valve [on-off].

 

[Yobbo]

xnuke and sreid,

Thank you for your swift response and helpfull information.

With best regards,

Karel Postulart, The Netherlands
Nuon Power Generation

 

[waross]

In support of;
"It depends..."
As an example of a dead band, we had a condensate return tank where the dead band was between about 15% and 20% of tank capacity. When the condensate return flow surged, the tank would go to almost 100%.
The normal operating level was between 20% and 90%. If the level went below 15% it was topped up to 20%. Not all of the steam was returned as condensate. From time to time, generally due to operator error, the level would go to 100% and excess water would overflow and be wasted.

Bill
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Jimmy Carter