avoid solids formation after a control valve ?

Dear M.A. Verduyn:

1) the bubbles may contribute to the "gel-bonding", remove them; 2) by dropping pressure you are lowering solubility, decrease the pressure before the valve; 3) when shearing through the valve you may be forming bonds (latex does this); decrease the pressure before the valve, or eliminate the valve.

Perhaps you could pass this fluid through a gear motor to let this fluid dissipate its energy *outside*...

David A. Smith

"N:dlzc D:aol T:com (dlzc)" schrieb im Newsbeitrag news:Ql9Mc.16544$Zr.11514@okepread01...

Thanks David, hope I understand you correctly So the picture is a bit like opening a beer can, when I open the beer can, I decrease pressure and bubbles form But when there are no sharp points on the glass less bubbles are formed, the sharp points relate to shearing in the valve Does this picture apply ? Marcel

Dear M.A. Verduyn:

Yes, and no. The beer is "metastable", so that the bubbles will eventually form. Your substance sounds "thixotropic", which simply means it thickens when stressed. You might want to do an internet search on this word. If you can minimize the stress, perhaps the thickening will not occur at all.

A better analogy *might* be cream vs. butter. It is cream until you agitate it, then it hardens to butter.

Try passing your flow through a meter or so of small diameter tubing, and see if the thickening still occurs at the end. Take care that the entrance and exit of the tubing is as smooth a possible. If this works well, then you might be able to use this in conjunction with an "air pinch valve" (APV) to do the fine control of flow. APVs are horrible for controlling gas flow (with any kind of pressure drop), because they sound like a continuous fart.

David A. Smith

iF IT'S ONCE THROUGH, YOU COULD ADD THE COMMON SALT TO FORM THE GEL AT THE LOW PRESSURE SIDE - BUT IT WILL BE A RECIRCULATORY SYSTEM i EXPECT - AND YOU NEED TO REDUCE THE SALT CONCENTRATION JUDICIOUSLY, THEN FIND A GEL MANUFACTUREr who knows of stabilizing additives - for hair set gel, aloe gel etc., etc., as well as your novel air conditioning app. (??)

Sorry about the upper case - I'm always hitting the caplock key - I should pull it off the keyboard

Brian W