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Keep in mind that enthalpy is not an absolute quantity, such as temperature or pressure, but always is relative to some base condition. Typically, the enthalpy is anchored to zero for the ideal gas state at a very low temperature, such as zero absolute. In an earlier version of the API Technical...

I suppose it would depend on the cooler design, and the relative contributions to total "R" of outside film coefficient, foam insulation, and inside film coefficient. Then there is the matter of separate areas for heat transfer: wetted and unwetted inside foam surfaces. The contact of water with...

Maybe someone who actually works with A/C or heat pump equipment can comment on this. Obviously, the compressor must pump the vaporized refrigerant from the evap side up to a pressure such that the equilibrium temperature of the liquid condensed in the condenser is greater than the temperature...

Another way to look at it is that as the V/L system approaches the critical point the properties of the two phases must become the same (volumes, enthalpies, compressibilities, viscosity, etc). Since the V & L enthalpies become the same, the heat of vaporization must become zero. Also, the...

When talking about efficiency in a refrigeration cycle, it all comes down to the temperatures of heat source and destination. The refrigerant must be evaporated at some temperature colder than the source, and it must reject the heat absorbed at a temperature higher than the destination. The...

Vapor pressure of water at 183 C is 1073 kPa, but that is absolute pressure. Your "1000 kPa" - is that gauge pressure? If so, you have liquid water coming out and a fair amount of heat is being left in the well. If your stated exit pressure is absolute, then it doesn't look like anything...

I agree with hanon's reply. The Brown-Souder chart is good for either absorption or stripping in simple separations. Basically, it is a semi-logarithmic plot of fraction not absorbed or stripped vs. absorption or stripping factor (A=L/VK, S=KV/L). The equations are the same: (1-f) =...

Somewhere on: http://groups.google.com/group/comp.lang.fortran there was a few months ago a post with a listing of available Fortran compilers. There are two open source freebies out there, along with (by one quote) seven commercial ones. It isn't clear what you mean by the impact of MS Visual...

A crude column configuration lets one draw multiple products from a single configuration having one heat source (furnace) at the bottom. Each product will not be pure, as in a chemical type process, but will cover a range of distillation temperatures; just how narrow a range depends on the...

An experimental measurement for glycerine (glycerol, propanetriol) is 18.18 C.

If I understad the description of your configuration, your original design uses the plate HX to pass heat from the superheated vapor to the liquid to vaporize it. Given the sensible heat of the vapor vs. the latent heat of the liquid, having a 64/36 vapor/liquid mix tells me (and the simple heat...

Zekeman, your final calculation is somewhat dependent on the value used for heat of combustion. I suspect your 140,000 BTU/lb is a gross heat of combustion, because the net heat for a typical no. 2 fuel oil is more like 125,000 to 130,000 I believe. Also, your density (7.5 lb/gal) seems high...

Mariatr, in your post of 25 Sept you said: ----------- "If we return to the column in the same tray as the feed (21st tray), the effect is exactly the same as preheating the feed. The main problem in this scenario is that reflux increases a lot (from 20 up to 30 m3/h)... However, if we return...

For D-limonene, NBP= 450.6 K, Tc= 653 K, and vp= 1.5 atm at T=468.6 K.

Tell us more about the exchanger configuration. Presumably it is horizontal, with CWS on the tube side, condensing on the shell. For the most part, if you get vapor out at 100 F, then the liquid will approach that too, except that condensate may run along the bottom without as much subcooling...

The "TL" and "TR" format specifiers just change the position in the current line where the next part of the output will go; they don't result in insertion of tab characters. Doing what you want is fairly easy. Basically, you want to write a character that has the value of the tab, which is 09...

The Jacobian inverse can be stored and reused to start off a re-calculation of the column. If the new feeds to the column are not much different and the specifications have not been changed much, then the saved matrix often is a good estimate of what it would be if a new Jacobian were to be...

For a heat pump type of system to handle the winter as well, check out the "Cold Climate Heat Pump" (CCHP), by Nyle Specialty, Bangor ME. Someone else does the marketing currently. I have been following this for a few years, am thinking of using it for a new house in a couple of years. They have...

A google on the matter turned up the reference below and many others. http://groups.google.com/group/microsoft.public.fortran/browse_thread/thread/c08cf53a036c9225/3f7c2b28665a855b%233f7c2b28665a855b

From the last post, mentioning cooling to 200 C by blowing air through a double-pipe HX makes me wonder about the scale of this operation. What is the flow of the hot stream? Is this a very small-scale system or something on a commercial scale? Normally an air-fin array would be used, with a...