automatic skimmer

kevinws

has any one heard of a automatic skimmer for a steam boiler ?

nicholas bonham-carter

auto-skimmer

someone should make one, so the installer/homeowner is not forced to sit for hours/days next to a  pipe dribbling into a bucket.

i think the following arrangement might work [at least on my peerless with a side tapping for the steam outlet]. right now, it is the skimming port with a large elbow, and valve and nipple pointing down. if i piped that into the boiler drain tapping, with an extra "t" and valve, the oily water would get thrown up into this skimming leg, and the water level will always be at the waterline of the boiler, because of the connection to the boiler bottom. a small percentage of each splash will be the oily water, which then can be periodically emptied by opening the valve on the "t". gradually, the oils will have been emptied out. i would experiment with that sometime, but later rather than sooner, as i have already spent my time sitting on the washing machine, watching the temporary extension pipe dribbling into the floor drain!--nbc

Dave in QCA

For Process Boilers

These are available for high pressure process type boilers.  But the skimming opeation on these boilers is acutally a top blowdown used to control the amount of total desolved solids.  The skimmer tube is usually a 1.5"  or 2" pipe which has a series of holes drilled in it, that extends accross the boiler, just below the water line.  When the skimmer is opened, it bleeds off the boiler water from the top, where the level of dissolved solids is the highest.  Undesolved solds such as pieces of lime scale, sludge, etc., fall to the bottom and are flushed out via manual blowdown.  Here is a diagram, albeit a poor one, http://www.ges-inc.com/BoilerWater.gif   

The automatic skimmer control samples the water by opening at a regular interval, say every 60 minutes.  As the water passes through the piping, an electrode senses the conductivity, and will hold the skimmer in the open position until the conductivity falls to the set point, at which time the skimmer automatically closes.   Here is a link to a manual for a typical automatic skimmer control.  http://www.advantagecontrols.com/downloads/pdf/M-Analog_Boiler.pdf



However, this type of skimming and this type of control is NOT the same procedure that is used to remove the oils from a new cast iron sectional steam boiler.