Q: So you want to start enacting some Light Green Machine Institute principles in your mill. Where do you start?
A: Small structures. Traditionally when we have added small structures (to support a drive or some other piece of equipment placed in space), we have designed a conventional structural steel platform.
This is the lazy way to go about executing this task--mimicking the kitchen table.
First, think of this--a plane in space is defined by three points, so why not use three legs instead of four? That's one way to reduce the size and weight of the structure.
But let's go further: why not use two legs and make a cantilever structure? Frank Lloyd Wright did wonders with cantilevered structures at Falling Water. We have much more sophisticated calculation methods than old Frank's structural engineers ever had. You'll reduce weight and make cleaning and servicing tasks much easier.
But why stop here? Go the full distance and use one large diameter steel leg. Look at the large billboards erected seventy or eighty feet in the air next to expressways--they have this huge flapping sail on the ends and they have one large, carefully engineered pipe support. Your dinky little platform can surely be built to such standards. It will be lightweight and easy to maintain and clean. Its total installed cost will be less than that spidery abomination your predecessor installed.
Think light, do light.
Jim
And a bit more on dryers from Dave Bennett:
Hi Jim;
It is heart-warming to see positive discourse on better ways to do such a basic papermaking process - dry the sheet!
Interesting aspects of this to me are less whether the dryer is made from aluminum alloy or steel, whose very high allowable stress means it can be about 1/4" thick, and with flat, insulated heads, etc., give aluminum a strong challenge in the heat transfer process, but why?
a) This concept has never been (publicly) computer-modeled with simple heat flux software to show the influence of metal, size, surface roughness, etc. on sheet drying efficiency. This can be done simply by a university student or by a dryer manufacturer not named Toscotec or Ippel!
b) No dryer manufacturer serving the NA market, without even making an actual dryer, has yet methodically investigated this technology in order to offer their customers a modern, "energy efficient" (Green?) and definitely SAFER dryer with substantially lower cost of ownership? (Onerous TAPPI/insurer inspection requirements are not required with ductile dryer material.) This would virtually show the technical feasibility and expected economic benefits - essential keys to considering winning an order.
As I've previously mentioned in this forum, in addition to the benefits listed above, a welded steel dryer costs less than a gray (or ductile) cast iron dryer of the same OD and requires significantly less energy to drive because it weighs so much less.
In the past 10 years my efforts to interest Metso, Voith and GL&V in this "model the benefits and they will come" approach for dryers have been as quixotic as my efforts to get mills to use non-metal pipe for white-water; specify CPVC instead of FRP for chlorine dioxide piping, and replace brick linings in bleach towers with modern stainless steel sheet linings, to mention just three, totally feasible ways mills can save loads of maintenance dollars, which few mills seem to have.
Perhaps the New Year will bring greater enlightenment in a few key places to improve the industry's health.
I certainly hope 2015 brings you good health and productive times at work and at home.
Best regards again,
Dave
with "LGMI Frontiers" in the subject line.