Posted by Raymond on June 17, 2001 at 12:49:39:
In Reply to: to manny silver tarzan & raymonds posted by zaib on June 17, 2001 at 08:12:59:
: my no.2 question was that how we will come to know that what percentage of continuous blow down (c.b.d.)valve we should open so that we may keep concentration of dissolved solid in boiler water within limits. you know that there is a scale fitted on c.b.d. valve which shows opening of c.b.d. valve in percentage. (simply i want to ask you , is there any formula that can tell us what percentage of c.b.d. valve we will need to open to control the t.d.s. of boiler water. as a friend has already suggested that it can be adjusted on the basis of c.c. i want to know how we will adjust c.b.d.)
: thanks.
The correction, by the amount of blow down, of boiler water mineral concentration as to be based on its quality. Quality control is either done in line, continuously, or otherwise manually with a frequency based on experience.
I f you have an in line continuos quality control you can start thinking of controlling the blowdown with this signal.
If water analyses are done an a say daily frequency you have to alter the blowdown valve according to the quality analyses results.
If production and feed water quality remain stable. You’ll find after a while that very little has to manipulated on your blow down valve. If on the contrary water quality and steam production varies a lot corrections will have to be made that’s live.
h.f.
Raymond