Rapid Engineering CTHN-40, Руководство по установке и эксплуатации

Страница: 45 / 100

SECTION 9: M
ULTIBURNER
H
EATER
I
NSTALLATION
39 of 91
9.6.3 Herringbone Layout and Manifold Tube
Length Rules
The herringbone layo u t is essentially several T
layo u ts stacked together. Therefore, the same
principle for manifold t u be calc u lation as u sed for T
layo u ts is u sed for herringbone layo u ts, w ith one
exception. In a herringbone layo u t, the manifold
t u be length bet w een tees (or crosses) as w ell as
bet w een the last tee (or cross) and the p u mp is
calc u lated by dividing by 1.5 as sho w n in the T
example on Page 37, Section 9.6.2 . The only
manifold t u be length in a herringbone layo u t that is
not divided by 1.5 is any manifold t u be length located
bet w een the end of the radiant t u be and a tee or
cross.
Example: Consider a herringbone layo u t similar to
the layo u t on the left in Figure 25 , having ten CTHN-
100 b u rners. Ass u me that each heater has 40' (12 m)
of radiant t u be and 10'(3 m) of manifold t u be before
the connecting tee or cross.
According to Table 10 each b u rner m u st have at least
40' (12 m) of radiant t u be, also each b u rner m u st
have bet w een 6' (2 m) and 45' (13.5 m) of manifold
t u be. Each b u rner has already met the minim u m
manifold pipe req u irement d u e to the 10' (3 m) of
manifold t u be before the connecting tees and
crosses. The maxim u m manifold t u be length for the
entire system is 10 b u rners X 45' (13.5 m) = 450'
(135 m). S u btract the 100' (30 m) that has already
been u sed before the connecting tees/crosses and
350' (105 m) remains.
Since the remaining manifold is located either
bet
w een or after connecting tees or crosses, the
manifold length m u st be divided by 1.5. 350' (105 m)/
1.5 = 233' (70 m). Therfore, u p to 233' (70 m) can be
u sed bet w een the branches and also bet w een the
last cross and the p u mp.
FIGURE 25: Herringbone Layout
Last Cross
Manifold tube
between joining
tee and pump.
Manifold tube between
radiant tube ends.
Tee
Pump
Cross (3)
Tee
Pump
Last Tee
Burner
M u ltiple opposing ro w s of b u rners: p u mp placed at the end of the manifold t u be or some w here bet w een
the b u rners.