10-01-2012, 01:21 PM
(09-16-2012, 04:56 PM)Rickabilly Wrote: Often the easy way to regulate flow when using a centrifugal blower is by use of a butterfly valve, as RPM vs flowrate curves are far from linear and with little back pressure just plain difficult to manage, but, with a correctly sized butterfly; a closed butterfly is closed and at half open the flow is around half of full flow and open is full flow.
Yes Mr Sunset,
That is exactly what I was saying when I posted this above, to get good simple control just throttle the flow rather than mucking around with expensive RPM control and fighting with pump delivery charts.
On a few of the other posts listed;
When using a hair dryer for blast air, make sure you use the heating element as it will help keeping the combustion process going and also make the process more efficient. better still use a paint stripper gun as more heat is "more good" and I find them to be cheaper to buy as a general rule.
Regarding the loss of swarf to oxidation, covering the pot and mixing the brass swarf with crushed charcoal, or at least adding a second pot inside the melt pot full of crushed(6-15mm) charcoal or coke, as the coke oxidizes the oxygen inside the closed pot is used up which prevents the swarf being lost to oxide, it works with most metals, use it where carbon content in the final metal is not an issue, it is a common metallurgical practice and has been used as long as metal has been smelted, as a matter of fact add a little flux, (crushed limestone or borax) and you can even convert some of your oxides back to metal!
When heat treating, this added carbon method prevents scale build up on the surface of most metals especially iron based metals, but keep the carbon away from the steel in the furnace.
Regards
Rick
Whatever it is, do it today, Tomorrow may not be an option and regret outlasts fatigue.