Tài liệu Reboiler typer

REBOILER APPLICABILITY Type Flow Layout Vaporizatio n Range % Kettle Gravity Horizontal 20-100 P 20-80 R Thermoshyphon Gravity Once-through, vertical 20-30 R Thermoshyphon Gravity Circulating, vertical 20-30 PP 20-100 O Thermoshyphon Gravity Horizontal Forced circulation Forced Horizontal -C 20-40 PP,R 20-60 PP,P 20-100 O 20-60 Sub-in bundle None Horizontal 0-100 Falling film Gravity Vertical, cocurrent 0-90 Falling film Pumped Vertical, cocurrent 0-90 Falling film Gravity 0-80 Falling film Pumped Horizontal, spray distribution Horizontal (alltype) Vertical (all-type) Vertical, counter-current 0-60 Suited for High vaporization -4 Vacuum service -3 Two phase feed -4 Simple hydraulics Wide boiling range mixtures -4 Reduced piping -3 Lower duties High purity system Reduced piping -3 High vaporization -4 Lower duties High purity systems Large sizes -3 Reduced pressure drop Problems with Dirt collection Heavy end accumulation Large size and higher cost Heat flux limits Vacuum services -2 Tower height requirements Vacuum services -2 Tower height requirements Complex return flow, flow instability in piping Difficult to size High viscosity -3 Extra pump cost, size, power and Fouling service -4 maintenance Higher once-through vaporization Eliminate process piping -4 Dirty service -1 Vessel foundation loads Bundles maintenance Require attention to tower baffling and level control Bundle length limited by tower diameter Heat sensitive system -4 Overall unit height Vacuum systems -3 Sticky fouling systems Complex liquid distribution at high vaporizations High viscosity Heat sensitive system -4 Sticky fouling systems Vacuum systems -3 Complex liquid distribution at high vaporizations High viscosity Heat sensitive system -4 Sticky fouling systems Vacuum systems -3 Complex liquid distribution at high Adds extra fractionation vaporizations High viscosity Heat sensitive system -4 Vacuum systems -3 Large sizes, Dirty services Reduced plot area required -3 Dirty and fouling services -2 Large sizes P= Possible, R= Recommended, PP= Per pass, O= Overall, C= Most common, 4= Excellent, 3= Good, 2 = Poor, 1= Avoid Notes: Vaporization range in percent of nets liquid traffic entering the reboiler