Furnace"Cabin Style Direct Fired Heaters", 29 Jul 2010:
Interpretation of natural draft burner data.Clearance datafloor
vertical burner (see radiant section sketch)23.940Gas firing per
API 560Oil firing per API 560Oil or gas firing based on
(1)23.9420.0burner distance fromburner distance fromburner heat
releaseburner distance fromburner heat releasewall tube CL
levelroof tube CL levelwall tube CL levelroof tube CL levelwall
tube CL levelroof tube CL levelMM Btu/hMM kcal/h[B] m[A] m[B']
m[A'] mMM kcal/h[B''] m[A'']
m20.50.612.770.511.941.00.763.960.843.661.01.13.161.50.915.160.994.881.51.24.382.01.076.321.146.102.01.35.6102.51.227.521.307.322.51.47.4123.01.378.711.458.53143.51.529.911.609.75164.01.6811.10184.51.8312.29Estimated
clearances from 95 MM Btu/h (NHV) burner to tube CL (centerline) -
natural draft9523.97.7058.17.7759.123.95.7666Estimated clearence
from 6'' tube CL (centerline) to the internal refractory wall (1):
m0.23Estimated clearances from 95 MM Btu/h burner to refractory
wall - natural draft,
m9523.97.9358.38.0059.423.95.9966.3NotesaAssumptions for mentioned
radiant section are presented in the scheme beside(vertical burner
and horizontal tubes around the walls)bClearence of 6" tube CL from
refractory wall should be 0.229 m (that is 9 in) (1)radiant section
sketchReferences(1)P. & M. Mitsopoulos ''Applied numeric
methods in Industry - Fortran programming'' (in Greek), ION
publishers, 1994.English, Greek and Romanian references in their
book. Chapter 3.3.23 (58 pages) devoted to refinery furnace design
through an example, also including following notes.--Typical
dimensions of a (cabin type) radiant section: maxL=30 m, W=4-6 m,
maxH=12 m (first tube row 1 m from floor).--Typical heat release in
furnace radiant (or convenction) section (based on NHV) : 36000 -
72000 kcal/m3/hr.thusconcerning total heat release of 68/0.81=84 MM
Btu/h=21.168 MM kcal/hresulting radiant chamber volume is 294 - 588
m3 . This chamber can be of (say) 3.7 m x 14.5 m x 9.5 m, with 10
burners along it of 10 MM Btu/h each.noteMinimum length is
considered as (1.22+0.23)+9x1.22+(1.22+0.23)=13.88 m between
refractory walls, assuming distance [B]=1.22 m between burner
centerlines, whichis uncertain (can be shorter?) since no relevant
data has been found.(2)W. L. Nelson ''Petroleum Refinery
Engineering'', 4th edition, McGraw-Hill (1958)Chapter 18 (40 pages)
deals with furnace (tubestill heater) design, in a practical and
comprehensive manner. But no mention on burner clearance.Subjects
similar to those referenced by Ankur in previous post are also
touched, of course as of 1958.
Furnace0.60962.768600.83823.657611.90.7623.9624200.99064.87681.13.10.91445.15621.1436.0961.24.31.06686.32461.29547.31521.35.61.21927.51841.44788.53441.47.41.37168.71221.60029.75361.5249.9061.676411.09981.828812.2936
[B][A][B'][A']API 560API 560Ref (1)Ref (1)burner heat release,
MM kcal/h (LHV)Burner CL clearance, my = 2.419x + 1.2192R2 = 1
[?][B][A]Burner
