more positive news., page-11

contrarian how can you possibly say with a straight face that:

"As for the 100metres of piping, well you'd be lucky to see any heat losses once the machine is operational for more than 10 minutes"

What is the basis for this assertion?

A brief Google search I conducted shows that heat loss from piping is a big issue. Here is an answer provided by someone who is clearly an engineer to address the same problem in an unrelated installation:

"Process85,

First of all I cannot understand your logic of not having any insulation on a 500 m length piping with a process temperature of 220 deg C. This is certainly not good engineering practice. You definitely need to provide heat conservation insulation. To me, providing insulation doesn't seem to be such a big problem. The heat loss calculation for insulated pipe is calculated as follows:

q/l = 2.PI*Km*delta T / Ln (Do/Di)

where

q/l = heat loss in Btu/h/ft

Km = Thermal conductivity of insulation material, Btu/ft*h*degF @ avg temperature

delta T = Process Temperature, deg F - Acceptable Surface Temp at top of insulation cladding, deg F
(Note: In your case process temp is 220 deg C or 428 deg F. An acceptable surface temperature would be 49 deg C or 120 deg F. However, the end user can decide the surface temperature at the insulation cladding surface).

Do = Diameter of pipe including insulation thickness, feet = OD of bare pipe + 2*insulation thickness

Di = OD of bare pipe in feet.

It is important to note that for a given insulation thickness, higher the delta T i.e. lower the surface temperature selected at the cladding surface, higher the heat loss.

An industry thumb rule is to select an insulation thickness to have a heat loss less than equal to 100 kcal/h/m2 (36.9 Btu/h/ft2).

Hope this information helps.

Regards,
Ankur."

For those who wish to further investigate this issue, this website is a start: http://www.cheresources.com/invision/topic/6248-heat-loss-from-fluid-flowing-through-uninsulated-pipe/

ERJ, perhaps you would care to elaborate on whether this heat loss issue is a concern or not (facts and evidence please).

Contrarian, despite the fact the ERJ has performed dismally and against the predictions you have been making for years (and the hopes I have had), I have no personal animosity towards you -in fact the opposite. But PLEASE don't make predictions or assertions stating THEY ARE FACT about things that you either don't know about or CAN'T predict.

Apart from that lets all have a happy Friday.


These days I'm too ashamed to advertise what companies I hold.


Cheers, SJB

All in my humble opinion.