Steam or Air ? 1

[ayfarm]

Scenario is to run say min. 5000 CFM aircompressors blowing several underwater (100 ft sea) jet nozzles on and off cycle at 300 psi operating. Would steam be cheaper instead? How about freeze up and enviro concern at sea? What nozzle valve design would work to prevent soil plug ups? Please help.

 

[butelja]

Insulating the underwater steam line would be a challenge to say the least.

 

[poetix99]

I really think that for mechanical cleaning you would be a lot better off with air, primarily because of the possible problems with steam.

If you did adequately insulate a steam line, you would have very different jet behaviors with air and with steam.

The steam would very rapidly condense at the jet discharge upon contacting cold seawater or cold soil, etc. The steam jet condensation actually tends to be periodic, although at a very high frequency (this is not a vortex phenomenon, by the way).

The air would (obviously) not condense but will expand. The mechanical "blowing" effects are greater with the air jet (scrubbing bubbles).

The cyclic duty also seems to be a potential problem for the use of steam. You could easily induce water hammering while the steam is not actively discharging: water would be drawn up the steam line and possibly cause mechanical damage depending upon the piping details and the rapidity of the condensation of the "idle" steam. A check valve near the discharge might solve this, but could cause other problems that I haven't thought through to.

 

[ayfarm]

I appreciate your input poetix99. Trying to quantify the "effectiveness" of the nozzle "velocity" to reduce the skin friction of the soil is a nightmare. I suppose, "modelling" might help, although the scale factor is so small that accuracy could become a problem. Thanks. Roque Engineers