I would like to use a water seal instead of a steam trap. I will design the water seal "p trap" at the highest pressure I expect. This pressure will be 1.75 PSIG or 49 inches w.c. I included a 1 PSIG or 28 inch additional water column above the water seal to aid in back pressure issues...
The total length of the tunnel is 120 ft of 18 inch duct. Looking at 210 cu. ft of air now.
I calculated the heat loss to be about 10,000 btu/hr using 1 ft thick fiberglass insulation with outdoor temperature of 30 degrees and inside temp of 275.
The KW requirement for a heater can be found...
Here is my new idea. Heat the air incrementally until desired setpoint then close off the duct heater section and run windtunnel. Using an electric duct heater sized at 20 kw instead of 310kw. Maintain heat loss with heat trace cable system. See attached...
Problem: How to heat air from 30ºF to 275ºF in a wind tunnel. Initially the air must be heated then maintained. Heater coil/medium cannot be in windtunnel (test particles would collect on them). Thus air must be first heated then introduced into the wind tunnel.
Specifications:
Volume Air in...
PROBLEM: CONFLICTING MATERIAL COMPATABILITY FOR 60ºF-130º AT 100PSIG PROPYLENE GLYCOL (DOWFROST HD.
SOURCE
AST, MECHANICAL SEAL MATERIAL SELECTION GUIDE
NBR:NO
EPDM:NO
VITON:YES
SOURCE
CHEMICAL RESISTANCE GUIDE FOR ELASTOMERS II
NBR:YES UP TO 250ºF
EPDM:YES UP TO 70ºF
VITON:YES UP TO...
I found two excellent sources for o-ring material compatability.
http://www.parker.com/o-ring/fcg/fcg.asp
http://www.bray.com/apps/braymat/braymat.cfm
EPDM is recommended for PG.
I AM IN SEARCH OF A COMPATIBILITY CHART FOR PROPYLENE GLYCOL (DOWFROST HD) WHEN SELECTING SEAT MATERIALS FOR BUTTERFLY VALVES. SPECIFICALLY: EPDM, NBR, PTFE, SINCE THESE ARE THE MOST COMMON AND LEAST EXPENSIVE.
THANKS.
I AM IN SEARCH OF A COMPATIBILITY CHART FOR PROPYLENE GLYCOL (DOWFROST HD) WHEN SELECTING SEAT MATERIALS FOR BUTTERFLY VALVES. SPECIFICALLY: EPDM, NBR, PTFE