Rapid Engineering CTHN-40, Руководство по установке и эксплуатации

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SECTION 9: M
ULTIBURNER
H
EATER
I
NSTALLATION
37 of 91
9.6.2 T and Fork Layouts and Manifold Tube
Length Rules
See Page 37, Figure 23 through Page 38, Figure 24
for diagrams of T and Fork layo u ts. The T and Fork
layo u ts have a tee or cross (called the "last tee" or
"last cross") w here the comb u stion gases in the
system enter the tee or cross w ith directly opposing
flo w directions, w hich creates an added so u rce of
press u re drop in the system. This additional so u rce
of press u re drop req u ires some difference in ho w the
allo w ed manifold length is calc u lated. In this case,
w e have to differentiate manifold t u be that is located
bet w een the radiant pipe and the last tee (or cross)
from manifold t u be that is located bet w een the last
tee (or cross) and the p u mp.
First determine the length of manifold t u be bet w een
the radiant t u be end and the last tee (or cross). Do
not co u nt any t u be length t w ice. No w refer to Page
34, Table 10 and find the maxim u m manifold t u be
length for each b u rner. Add together the maxim u m
manifold t u be length on the table for each b u rner in
the system, this is the maxim u m manifold t u be length
for the entire system.
To determine the maxim
u m manifold t u be allo w ed
bet w een the last tee (or cross) and the p u mp:
S u btract the manifold t u be length bet w een the
radiant t u be and the last tee (or cross) from the
maxim u m manifold length for the entire system, then
divide that n u mber by 1.5.
Example: Consider a T layo u t w ith t w o CTHN-100
b u rners. See Page 37, Figure 23 . Ass u me that 15'
(4.5 m) of manifold w as u sed from each radiant t u be
end to the last tee. Page 34, Table 10 indicates that
each CTHN-100 b u rner can have a maxim u m of 45'
(13.5 m) of manifold t u be. Therefore the maxim u m
manifold t u be length amo u nt allo w ed bet w een the
last tee and the p u mp in this case is
([45' + 45']-[15' x 2])/1.5 = 40' or in metric,
([13.5 m + 13.5 m]-[4.5 m x 2])/1.5 = 12 m .
FIGURE 23: T Layout
Pump
Manifold tube between joining tee
and pump.
Last Tee
Burner
One pair of b u rners.