Eclipse Combustion ImmersoJet Series Guide

Immersion
Burners
version 2.20
ImmersoJet Series
No. 330, 10/02
Design Guide

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
Copyright I997 by Eclipse Combustion,Inc.All rights reserved
worldwide.This publication is protected by federal regulation and
shall not be copied, distributed, transmitted, transcribed or
translated into any human or computer language, in any form or
by any means, to any third parties, without the express written
consent of Eclipse Combustion, Inc., Rockford, Illinois, U.S.A.
We reserve the right to change the construction and/or
configuration of our products at any time without being obliged
to adjust earlier supplies accordingly.
The material in this manual is believed adequate for the intended
use of the product. If the product, or its individual modules or
procedures, are used for purposes other than those specified
herein, confirmation of their validity and suitability must be
obtained. Eclipse Combustion, Inc. warrants that the material
itself does not infringe any United States patents. No further
warranty is expressed or implied.
We have made every effort to make this manual as accurate and
complete as possible. Should you find errors or omissions, please
bring them to our attention so that we may correct them. In this
way we hope to improve our product documentation for the
benefit of our customers. Please send your corrections and
comments to our Documentation Manager.
It must be understood that Eclipse Combustion’s liability for its
products, whether due to breach of warranty, negligence, strict
liability, or otherwise, is limited to the furnishing of such
replacement parts and Eclipse Combustion will not be liable for
any other injury, loss, damage or expenses, whether direct or
consequential, including but not limited to loss of use, income of
or damage to material arising in connection with the sale,
installation, use of, inability to use or the repair or replacement
of Eclipse Combustion’s products.
Any operation expressly prohibited in this Guide, any adjustment,
or assembly procedures not recommended or authorized in
these instructions shall void the warranty.
COPYRIGHT
DISCLAIMER NOTICE
LIABILITY AND
WARRANTY
2

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
AUDIENCE
RELATED DOCUMENTS
About this manual
This manual has been written for people who are already
familiar with all aspects of an immersion burner and its add-on
components, also referred to as “the burner system.”
These aspects are:
• design/selection
• use
• maintenance.
The audience is expected to have experience with this kind of
equipment.
Design Guide No. 330
• This document
Data Sheet No. 330-2, 330-3, 330-4, 330-6, 330-7, 330-8
• Available for individual IJ models
• Required to complete design calculations in this guide
Installation Guide No. 330
• Used with Data Sheet to complete installation
Price List No. 330
• Used to order burners
• EFE 825 (Combustion Engineering Guide)
• Eclipse bulletins and Info Guides:
610, 710, 720, 730, 742, 744, 760, 930
Purpose
The purpose of this manual is to make sure that the design of a
safe, effective and trouble-free combustion system is carried out.
IMMERSOJET
DOCUMENTS
3

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
There are several special symbols in this document.You must
know their meaning and importance.
The explanation of these symbols follows below. Please read it
thoroughly.
dDanger:
Indicates hazards or unsafe practices which WILL
result in severe personal injury or even death.
Only qualified and well trained personnel are
allowed to carry out these instructions or
procedures.
Act with great care and follow the instructions.
wWarning:
Indicates hazards or unsafe practices which
could result in severe personal injury or damage.
Act with great care and follow the instructions.
cCaution:
Indicates hazards or unsafe practices which could result in
damage to the machine or minor personal injury.
Act carefully.
nNote:
Indicates an important part of the text. Read thoroughly.
If you need help,you can contact your local Eclipse Combustion
representative. You can also contact Eclipse Combustion at any
of the addresses listed on the back of this document.
DOCUMENT
CONVENTIONS
HOW TO GET HELP
4

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
Table of Contents
About this manual ............................................................. 3
Table of contents ................................................................ 5
Introduction ........................................................................... 7
Product Description .................................................................. 7
Safety.......................................................................................... 9
Introduction ................................................................................. 9
Safety ............................................................................................ 9
Capabilities ................................................................................... 10
OperatorTraining ....................................................................... 10
Replacement Parts ..................................................................... 10
System Design...................................................................... 11
Step 1: Burner model selection ......................................... 11
Step 2:Tube design................................................................ 13
Step 3: Control methodology ............................................ 15
Step 4: Ignition system ......................................................... 16
Step 5: Flame monitoring system ...................................... 16
Step 6: Combustion air system.......................................... 17
Step 7: Main gas shut-off valve train ................................. 20
Step 8: Process temperature control system ................. 20
Appendix.................................................................................. 21
Key to the system schematics ................................................. 22
1
2
3
5

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6

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
Introduction
PRODUCT
DESCRIPTION
Figure 1.1 The ImmersoJet Burner
1
The combustion gases from the burner scrub the inner tube
surface and produce high heat transfer rates. This, in
combination with the high velocity flow through the smaller
diameter tubes allows for system efficiencies in excess of 80%.
The smaller ImmersoJet tubes also have smaller bends which
means less tank space is occupied by the tubes.With a
combustion chamber that is integral to the burner body, the
new version of the ImmersoJet can sit lower on the tank than
previous ImmersoJet models.
FEATURES
7
The ImmersoJet (IJ) is a nozzle-mix tube-firing burner that is
designed to fire at high velocities through small diameter
immersion tubes. The standard burner includes a packaged
blower, actuator control motor, integral butterfly valve, ratio
regulator, burner body, combustion chamber, nozzle (specific to
fuel used), rear cover, spark and flame rods, and gas orifice (also
specific to fuel used).

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
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8

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
Safety 2
In this section you will find important notices about safe
operation of a burner system.
dDanger:
The burners covered in this manual are designed
to mix fuel with air and burn the resulting
mixture. All fuel burning devices are capable of
producing fires and explosions when improperly
applied, installed, adjusted, controlled or
maintained.
Do not bypass any safety feature; You can cause
fires and explosions.
Never try to light the burner if the burner shows
signs of damage or malfunctioning.
wWarning:
The burner is likely to have HOT surfaces.Always
wear protective clothing when approaching the
burner.
nNote:
This manual gives information for the use of these burners
for their specific design purpose. Do not deviate from any
instructions or application limits in this manual without
written advice from Eclipse Combustion.
Read this entire manual before you attempt to start the
system. If you do not understand any part of the information
in this manual, then contact your local Eclipse representative
or Eclipse Combustion before you continue.
INTRODUCTION
SAFETY
9

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
Adjustment, maintenance and troubleshooting of the mechanical
and the electrical parts of this system should be done by
qualified personnel with good mechanical aptitude and
experience with combustion equipment.
The best safety precaution is an alert and competent operator.
Thoroughly instruct operators so they demonstrate an
understanding of the equipment and its operation. Regular
retraining must be scheduled to maintain a high degree of
proficiency.
Order replacement parts from Eclipse only.Any customer-
supplied valves or switches should carry UL, FM, CSA,CGA and/
or CE approval where applicable.
CAPABILITIES
OPERATOR
TRAINING
REPLACEMENT PARTS
10

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
System Design 3
Designing a burner system is a straightforward exercise.The
steps are:
1. Burner model selection.
a. Determine net input required for the tank or process
b. Select tube efficiency
c. Calculate gross input required
d. Select burner model
2. Tube design.
3. Control methodology.
4. Ignition system.
5. Flame monitoring system.
6. Combustion air system: blower and air pressure switch.
7. Main gas shut-off valve train.
8. Process temperature control system.
Determine the net input required to the tank
The net input to the tank is determined from heat balance
calculations.These calculations are based on the heatup and
steady-state requirements of the process, and take into account
surface losses, tank wall losses and tank heat storage. Detailed
guidelines for heat balance calculations are in the Eclipse
Combustion Engineering Guide (EFE 825).
Select tube efficiency
The efficiency of the tube is the net heat input to the tank
divided by the heat input to the tube. Efficiency is determined by
the effective tube length. The diameter of the tube has little
influence on the efficiency. At a given burner input, the net input
to the tank is higher for a longer tube than for a relatively short
tube.
It is customary to size conventional immersion tubes for 70%
efficiency, a reasonable compromise between fuel economy and
tube length. However, small diameter tubes occupy less tank
space than conventional tubes, so their length can easily be
increased to provide efficiencies of 80% or more.
Calculate the gross burner input
Use this formula to calculate gross burner input in Bth/hr:
DESIGN
SS
SS
STEPTEP
TEPTEP
TEP 11
11
1
::
::
:BURNER MODEL
SELECTION
net output to tank
tube efficiency =gross burner input
11

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
.
BURNER MODEL
SELECTION (CONTINUED)
Figure 3.1 Capacity Guide
Applications requiring special consideration:
ImmersoJet burners are used for firing spray wash tanks, dip tanks,
and storage tanks such as those used for fire sprinkler systems.
Generally, the small bore system can be used wherever conventional
immersion burner systems are used, except where high heat flux off
the small bore tube can break down the tanks contents.
Zinc phosphate solutions
High heat fluxes break down the phosphate, forming a heavy
insulating sludge which deposits on tube surfaces and causes
rapid tube burnout. To reduce early tube failure, make the
immersion tube with electro-polished stainless steel, and limit
the burner to capacity shown in the limited capacity portion of
Figure 3.1 based on tube size.
Iron phosphate solutions
These are susceptible to the same problem described above for
zinc phosphate solutions. To reduce early tube failure, make the
immersion tube with stainless steel. Electro-polishing is not
required. Limit the burner to capacity shown in the limited capacity
portion of Figure 3.1 based on tube size.
Cooking oils
To avoid burning the oil, limit heat flux to 50 Btu/hr per square
inch of tube area.
Highly viscous liquids
All immersion systems depend on natural convection currents to
carry heat away from the tube and throughout the tank.
Convection is minimal in high viscosity solutions, such as asphalt,
residual oil or molasses. This can severely overheat the liquid
around the tube..
cCaution
Do not use the ImmersoJet for highly viscous fluids
Select burner model
Choose a burner model with a maximum capacity greater than the
gross burner input calculated previously. Refer to Figure 3.1.
12
2” IJ V 2 2 50 190,000 55 235,000 69 370,000 108
3” IJ
V 2 3 80 440,000 129 550,000 161 850,000 249
4” IJ
V 2 4 100 830,000 243 1,000,000 293 1,800,000 527
6” IJ
V 2 6 150 2,000,000 586 2,500,000 732 3,600,000 1054
8” IJ
V 1 8 200 n/a n/a n/a n/a 8,000,000 2344
Model
Tube Size
mm
Low-Pressure
Packaged Blower
Btu/hr.kW
High-Pressure
Packaged Blower
Btu/hr.kW
Remote Blower
Btu/hr.kW
in.
Limited Capacity
Zinc
Phosphate Iron
Phosphate
Btu/hr. kW
110,000 32
Btu/hr. kW
220,000 64
1,800,000 527 3,600,000 1055
250,000
440,000
1,000,000
73
129
293
500,000
880,000
2,000,000
146
258
586

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
6,500,000 7,000,000 7,500,000 8,000,000
70%
65%
75%
80%
85%
200
0
20
40
60
80
100
120
140
160
180
Effective Tube Length, in Feet
500,000
1,000,000 1,500,000 2,000,000 2,500,000 3,000,000 3,500,000 4,000,000 4,500,000 5,000,000 5,500,000 6,000,000
Heat Transfer To Tank, Btu/hr
0
Determine effective tube length
Find the required effective tube length using the previously
selected tube efficiency, net heat input values and the following
figures 3.2. or 3.3. The effective length of a tube is the total
centerline length of tube covered by liquid.
SS
SS
STEPTEP
TEPTEP
TEP 2:2:
2:2:
2: TUBE DESIGN
Figure 3.2 Effective
Tube Length to 200 ft.
Figure 3.3 Effective
Tube Length to 50 ft.
13
See
area
enlarged
below.
35
40
45
50
Effective Tube Length, in Feet
0 50,000 100,000 150,000 200,000 250,000 300,000 350,000 400,000 450,000 500,000
Heat Transfer To Tank, Btu/hr
0
5
10
15
20
25
30
80%
75%
70%
65%
85%

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
Efficiencies 80% or more
1/2”
Drain
Pipe
Stack–
Twice
Tube
Diameter
Efficiencies less than 80%
Elbows
• Use standard and sweep elbows only.
• For maximum tube life place the first elbow eight tube
diameters from the burner.
Stack
• Make sure that the stack is large enough to handle the
heated exhaust flow plus the dilution air.
• The stack must be at least one pipe size larger than the tube
exhaust.
nNote:
If you use a common stack for more than one burner, then
make sure that the stack is large enough to handle the
exhaust flow plus any dilution air from all the burners.
Detailed guidelines for flue sizing calculations are in the
Eclipse Combustion Engineering Guide (EFE 825).
Stack
Draft breaking
hood
Dilution air
Tube exhaust
14
Draft breaking hood
A draft breaking hood is an open connection between the heater
tube exhaust and the exhaust stack. It allows fresh dilution air to
pass into the exhaust and mix with the exhaust gases.
The advantages of a draft hood are:
•
the burner operation is less sensitive to atmospheric conditions
• the temperature of the exhaust gases is lower when they
pass through the roof.
nNote:
Leave access between the draft hood and the tube exhaust. Install
a damper plate if acoustic feedback occurs in the tube.
Condensate provisions
If the immersion tube will operate at efficiencies less than 80%,
the exhaust leg can be raised through the liquid surface. For
efficiencies of 80% or higher, locate the exhaust stack outside of
the tank and provide a drain.
nNote:
Regardless of the exhaust design, pitch the immersion tube down
towards the exhaust so condensate will not collect at the burner.
cCaution:
At efficiencies of 80% or greater, low exhaust temperatures
will cause condensation to form in the tube at start-up or
during long idling periods. The higher the efficiency the more
condensation will increase
To prevent condensation/corrosion from shortening tube life or
disrupting burner operation, provide a condensate drain at the
exhaust and slope the immersion tube downward, away from
the burner.
Tube placement in tank
The tube placement height in the tank should be high enough to
avoid the possibility of sludge build-up on the bottom of the tank;
however, it should be low enough to avoid tube exposure due to
liquid level variations caused by evaporation or displacement. In
the latter case use a liquid level switch to shut down the burner.

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
P
2
1
4
P
1
23
4
Control methodology
ImmersoJet burners use a modulating on-ratio control system
as shown in Figure 3.3. To control the heat delivered by the
burner, adjust the air flow to the burner.The gas flow will
change in proportion to the air flow.
The burner will operate reliably at any input between the low
fire and high fire limits stated on the burner‘s Data Sheet.
SS
SS
STEPTEP
TEPTEP
TEP 3:3:
3:3:
3: CONTROL
SYSTEM
Components
Automatic butterfly valve
Ratio regulator: varies gas flow to
burner in proportion to air flow.
Automatic shut-off valve (optional).
Manual butterfly valve
Safety
valve
train
Figure 3.3 System Schematics
Loading line
Packaged blower
Remote blower with
External air butterfly valve–
Multiple burner zones
Safety
valve
train
Loading
line
Remote blower with
External air butterfly valve
Safety
valve
train
Loading
line
1
2
3
4
to other burners
15
P
1
2

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
For the ignition system you should use:
• 6000 VAC transformers
• full wave spark transformers
• one transformer per burner.
Do not use:
• 10,000 VAC transformers
• twin outlet transformers
• distributor type transformers
• half wave spark transformers.
ImmersoJet burners will ignite reliably at any input within the
ignition zone shown in the appropriate burner data sheet.
However, it is recommended that low fire start be used. Local
safety and insurance requirements demand that you limit the
maximum time that a burner takes to ignite. These time limits vary
from country to country.
The time that a burner takes to ignite depends on:
• the distance between the gas shut-off valve and the burner
• the air/gas ratio
• the gas flow at start conditions.
In the USA, with a time of 15 seconds to ignition, there should be
sufficient time to ignite the burners. It is possible, however, to have
the low fire too low to ignite within the time limit. Under these
circumstances you must consider the following options:
• start at higher input levels
• resize and/or relocate the gas controls
A flame monitoring system consists of two main parts:
• a flame sensor
• flame monitoring control
Flame sensor
There are two types that you can use for an ImmersoJet burner:
• U.V. scanner
• flame rod
You can find U.V. scanner information in:
• Info Guide 852; 90º U.V. scanner
• Info Guide 854; straight U.V. scanner
• Info Guide 855; Solid State U.V.I.R. scanner
• Info Guide 856; self-check U.V. scanner.
You can find flame rod information in:
• Bulletin / Info Guide 832
SS
SS
STEPTEP
TEPTEP
TEP 4:4:
4:4:
4: IGNITION SYSTEM
SS
SS
STEPTEP
TEPTEP
TEP 5:5:
5:5:
5: FLAME
MONITORING SYSTEM
U.V. scanner
Flame rod
16

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
Flame Monitoring Control
The flame monitoring control is the equipment that processes
the signal from the flame rod or the U.V. scanner.
For flame monitoring control you may select several options:
• flame monitoring control for each burner: if one burner goes
down, only that burner will be shut off
• multiple burner flame monitoring control: if one burner goes
down, all burners will be shut off
There are three recommended flame monitoring controls:
• Bi-flame series; see Instruction Manual 826
• Multi-flame series 6000; see Instruction Manual 820
• Veri-flame; see Instruction Manual 818
Other manufacturer’s flame monitoring systems can be used
with the burner if spark is maintained for a fixed time interval
and is not interrupted when a flame signal is detected during trial
for ignition.
ImmersoJet burners are sold in these configurations:
• Burner with integral low pressure blower.
• Burner with integral high pressure blower.
• Burner less blower.
nNote:
This section describes how to size a blower for burners
purchased less blower.
SS
SS
STEPTEP
TEPTEP
TEP 6:6:
6:6:
6: COMBUSTION AIR
SYSTEM
Effects of atmospheric conditions
The blower data is based on the International Standard
Atmosphere (ISA) at Mean Sea Level (MSL), which means that it
is valid for:
• sea level
• 29.92” Hg (1,013 mbar)
• 70ºF (21ºC)
The make-up of the air is different above sea level or in a hot
area.The density of the air decreases, and as a result, the outlet
pressure and the flow of the blower decrease. An accurate
description of these effects is in the Eclipse Combustion
Engineering Guide (EFE 825).The Guide contains tables to
calculate the effect of pressure, altitude and temperature on air.
17

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
Blower
The rating of the blower must match the system requirements.
You can find all the blower data in Bulletin 610.
Follow these steps:
1. Calculate the outlet pressure.
When calculating the outlet pressure of the blower, the total
of these pressures must be calculated.
• the static air pressure required at the burner
• the total pressure drop in the piping
• the total of the pressure drops across the valves
• the pressure in the immersion tube
• recommend a minimum safety margin of 10%
2. Calculate the required flow
The blower output is the air flow delivered under standard
atmospheric conditions. It must be enough to feed all the burners
in the system at high fire.
Combustion air blowers are normally rated in terms of standard
cubic feet per hour (scfh) of air.
An example calculation follows the information tables below:
Series SMJ turbo blower
COMBUSTION
AIR SYSTEM (CONTINUED)
DESCRIPTION UNIT OF MEASURE FORMULA SYMBOL
Total system heat input Btu/hr Q
Number of burners - -
Type of fuel - -
Gross heating value of fuel Btu/ft3q
Desired excess air percentage percent %
(Typical excess air percentage
@ high fire is 15%)
Air/Gas ratio - α
(Fuel specific, see table below)
Air flow scfh Vair
Gas flow scfh Vgas
Figure 3.4 Required calculation information
* Stoichiometric: No excess air.The precise amount of air and gas are present
for complete combustion.
Figure 3.5 Fuel gas heating values
FUEL GAS
STOICHIOMETRIC*
AIR/GAS RATIO
αα
αα
α (ft3air/ft3gas)
GROSS HEATING
VALUE
q (Btu/ft3)
Natural gas
(Birmingham, AL) 9.41/1 1,002
Propane 23.82/1 2,572
Butane 30.47/1 3,225
18

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
Application example:
A designer of a spray washer has determined the heat input for the
water tank requires 857,500 Btu/hr. Based on the size of his tank,
he has selected a tube efficiency of 70% which results in a gross
burner input of 1,225,000 Btu/hr.
Calculation example to determine the air flow
requirement:
a. Decide which ImmersoJet model is appropriate:
•
From the capacity table, either the 4” with a remote
blower (1,800,000 Btu/hr), or the 6” with the low-
pressure packaged blower (2,000,000 Btu/hr) have
sufficient capacity. For this example, the designer selects
the 4” tube because his tank size limits the amount of the
larger 6” tube that will fit.
• Select an IJ004, 4” diameter tube ImmersoJet burner with
a remote blower for a maximum firing rate of 1,225,000
Btu/hr.
b. Calculate the required gas flow:
V
gas
= Q/q = 1,225,000 Btu/hr / 1,002 Btu/ft
3
= 1,223 ft
3
/hr
• Gas flow of 1,223 ft
3
/hr is required.
c. Calculate the required stoichiometric air flow:
V
air-stoichiometric
= a (air/gas ratio) xV
gas
= 9.41 x 1,223 ft
3
/hr
= 11,508 ft
3
/hr
• Stoichiometric air flow of 11,508 scfh required
d. Calculate the final blower air flow requirement based on 15%
excess air at high fire:
V
air
= ( 1 + excess air %) xV
air-stoichiometric
= ( 1 + 0.15) x 11,508 ft
3
/hr = 13,234 ft
3
/hr
• For this example, final blower air flow requirement is
13,234 scfh at 15% excess air.
nNote:
It is common practice to add an additional 10% to the final
blower air flow requirement as a safety margin.
3.
Find the blower model number and motor horsepower (hp).
With the output pressure and the specific flow, you can find the
blower catalog number and the motor hp in Bulletin 610.
4. Select the other parameters:
• inlet filter or inlet grille
• inlet size (frame size)
• voltage, number of phases, frequency
• blower outlet location, and rotation direction Clockwise
(CW) or Counter Clockwise (CCW).
COMBUSTION
AIR SYSTEM (CONTINUED)
19

Eclipse ImmersoJet v2.20 Design Guide 330, 10/02
SS
SS
STEPTEP
TEPTEP
TEP 8:8:
8:8:
8: PROCESS
TEMPERATURE CONTROL
SYSTEM
nNote:
The use of an inlet air filter is strongly recommended.The
system will perform longer and the settings will be more
stable.
nNote:
When selecting a 60 Hz Blower for use on 50 Hz,a
pressure and capacity calculation is required. See Eclipse
Combustion Engineering Guide (EFE 825)
Step 6: Combustion Air
System: Blower and
air pressure switch
(continued)
The total selection information you should now have:
• blower model number
• motor hp
• motor enclosure (TEFC)
• voltage, number of phases, frequency
• rotation direction (CW or CCW).
Inlet filter with
replaceable filter
element
Air pressure switch
The air pressure switch gives a signal to the monitoring system
when there is not enough air pressure from the blower.
You can find more information on pressure switches in:
• Blower Bulletin 610
wWarning:
E clipse Combustion supports NFPA regulations,which
require the use of an air pressure switch in conjunction
with other safety components, as a minimum standard
for main gas safety shut-off systems.
Consult Eclipse
Eclipse can help you design and obtain a main gas shut-off valve
train that complies with the current safety standards.
The shut-off valve train must comply with all the local safety
standards set by the authorities that have jurisdiction.
For details, please contact your local Eclipse Combustion
representative or Eclipse Combustion.
nNote
Eclipse Combustion supports NFPA regulations (two shut-off
valves) as a minimum standard for main gas safety shut-off
systems.
Consult Eclipse
The process temperature control system is used to control and
monitor the temperature of the system.There is a wide variety of
control and measuring equipment available.
For details, please contact your local Eclipse Combustion
representative or Eclipse Combustion.
Step 7: Main gas shut-off
valve train
Air pressure switch
20