Pressure Atomized Oil System; Air Atomized #2 Oil; Gas Pilot; Fgr Duct System - Webster JBE Series Operation, Maintenance & Installation Manual

Forced draft burners, high swirl combustion head
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CAUTION
PUMP FAILURES CAUSED BY FOREIGN MATTER
IN THE OIL LINES WILL NOT BE COVERED BY
WARRANTY

6. Pressure Atomized Oil System

A pump is provided as standard with this system (Figure
C-8). There are several components that are required to
complete the oil system as indicated on the schematic.
The burner supplied oil pump suction should not exceed
10" hg.
The oil pump should be mounted close to the burner, so
that the pressure and flow can be properly controlled.
The oil supply and return lines must be piped to the
burner, with the components installed as shown in the
schematic. The motor base of the oil pump should be
bolted securely to the floor or some rigid base.

7. Air Atomized #2 Oil

The standard air atomized burner equipped for light
oil may not include the optional oil pump. Oil is to be
delivered to the burner at a constant 50 to 75 PSIG and
with a flow capacity that is at least 50% higher than the
rated nozzle capacity. For pump selections, the capac-
ity should be 50% over the nozzle capacity. A supply
and return line connection are required, along with the
components indicated. The lines must be sized
correctly to provide the required flow with minimal
pressure drop. The pressure in the return line should
not exceed 3 PSIG.
Equivalent Lengths of Pipe
(Use for calculating total
4"
5"
6"
Pipe diameter(in)
Mitered 90º elb
21.0 26.0
32
or "T" side flow
Standard 90º
8.7
10.8 13
elbow
Long rad 90º elb
7.1
8.7
10
(rad = 8 x dia)
Mitered 45º
5.5
6.7
8
elbow
FIGURE C-11
Equivalent Lengths of Fittings for FGR Duct
The oil supply and return lines must be piped to the
burner, with the components installed as shown in the
schematic. The oil pressure regulator must be located
close to the burner to provide a constant oil supply
pressure.

8. Gas Pilot

The typical piping arrangement for the gas pilot is shown
in Figure C-10. The supply is connected upstream of
the first manual gas valve.
JBE(X) Manual
Fittings
length)
8"
10"
12"
14" 16"
42
52
61
71
81
17
22
26
30
35
14
17
20
23
27
10
13
15
17
20

9. FGR Duct System

If the burner is equipped with Induced Flue Gas Recircu-
lation (IFGR), it will require a duct connection between
the stack outlet of the boiler and the air inlet of the burner
(See Figure C-13). FGR is used to reduce NOx emissions.
There can be different levels of NOx emissions that require
different quantities of flue gas and different FGR duct and
valve sizes. Proper sizing and installation of the FGR duct
must be done to provide the required emission control and
burner performance.
The FGR control valve is already installed on the burner
and the duct will connect to this point. Depending on the
duct size required, a pipe reducer may be required to
match the control valve to the duct. The control valve is
usually a smaller pipe size. The FGR shutoff valve may
also require a pipe reducer, depending on the duct size.
If the FGR duct is to be installed in the field, the following
procedures should be used to determine the best arrange-
ment. The process uses a "Trial and Error" sequence to
evaluate different possible duct arrangements.
a. Put together a duct arrangement based on a estimated
duct size.
b. Determine the equivalent total pipe length based on
the arrangement and fittings used.
c. Calculate the actual pressure drop in the duct using
the value in Figure C-12 for the drop per 100' of pipe.
d. If this pressure drop is higher than the allowed drop
(Figure C-12), select a larger duct size or fittings that\
have a lower equivalent length and repeat the steps.
e. If the calculated pressure drop is less than the
maximum drop, that arrangement can be used.
Figure C-11 can be used to determine the equivalent duct
length. Each fitting used in the duct has an equivalent
straight pipe length, which is given in the chart. By
adding up all of the equivalent lengths (including the length
when multiple fitting are used) and all of the straight pipe
lengths, the total equivalent length can be determined.
This number is used to determine the pressure drop.
Figure C-12 provides pressure drop information used in
sizing the FGR duct. The maximum FGR duct pressure
drop is given for different inputs and NOx levels. The duct
must be sized to be under this pressure. For a specific
duct design, the equivalent length is used with the
pressure drop per 100 feet of duct (selected from the
chart, for the burner input and NOx level). The total
pressure drop is:
Pressure drop = (drop per 100 feet)*(equivalent
length)/100
This is the pressure drop expected from the duct that was
selected. If the pressure drop is higher than the maximum
allowed drop, the duct must be modified to reduce the
pressure drop. This can be done by reducing the total
length, using fittings with lower pressure drops or using
larger pipe sizes. The pressure drop from the FGR
control valve and shutoff valve (if required) do not need to
be included in this evaluation.
Page 24
Section C - Installation

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