CleaverBrooks CBEX-DE Installation guide

CBEX-DE
Dryback Elite Boiler
250-800 HP
Operation and Maintenance
750-392 10/2019

TO: Owners, Operators and Maintenance Personnel
This operating manual presents information that will help to properly operate and care for the equipment. Study its contents carefully.
The unit will provide good service and continued operation if proper operating and maintenance instructions are followed. No attempt
should be made to operate the unit until the principles of operation and all of the components are thoroughly understood. Failure to
follow all applicable instructions and warnings may result in severe personal injury or death.
It is the responsibility of the owner to ensure all service, repair, and operating personnel have received proper safety training.
Proper operating techniques and maintenance procedures must be followed at all times. Although the components supplied afford a
high degree of protection and safety, due attention is required to the dangers and hazards inherent in handling and firing of fuel.
“Automatic” features, where present, should not be understood as substituting for the normal responsibilities of the attendant. Such
features merely alleviate certain repetitive chores, allowing more time for proper upkeep of the equipment.
This manual is intended for a general scope of application. Because of state, local, or other applicable codes, controls and safety de-
vices may vary considerably from those described herein.
It is recommended that a boiler room log or record be maintained. Recording of daily, weekly, monthly and yearly maintenance activ-
ities and recording of any unusual operation will serve as a valuable guide to any necessary investigation.
Most instances of major boiler damage are the result of operation with low water. We cannot emphasize too strongly the need for the
operator to periodically check the low water controls and to follow good maintenance and testing practices. Cross-connecting piping
to low water devices must be internally inspected periodically to guard against stoppages which could obstruct the free flow of water
to the low water devices. Float bowls of these controls, where applicable, must be inspected frequently to check for the presence of
foreign substances that would impede float ball movement.
The waterside condition of the pressure vessel is of extreme importance. Waterside surfaces should be inspected frequently to check
for mud, sludge, scale and corrosion.
It is essential to obtain the services of a qualified water treating company or a water consultant to recommend the proper boiler water
treating practices for your specific application.
The operation of this equipment must comply with all requirements or regulations of the owner’s insurance company and/or other
authority having jurisdiction. In the event of any conflict or inconsistency between such requirements and the warnings or instructions
contained herein, please contact Cleaver-Brooks before proceeding.
DO NOT OPERATE, SERVICE, OR REPAIR THIS EQUIPMENT UNLESS YOU FULLY UNDERSTAND ALL
APPLICABLE SECTIONS OF THIS MANUAL.
DO NOT ALLOW OTHERS TO OPERATE, SERVICE, OR REPAIR THIS EQUIPMENT UNLESS THEY FULLY
UNDERSTAND ALL APPLICABLE SECTIONS OF THIS MANUAL.
FAILURE TO FOLLOW ALL APPLICABLE WARNINGS AND INSTRUCTIONS MAY RESULT IN SEVERE
PERSONAL INJURY OR DEATH.
!DANGER
WARNING

CONTENTS
CHAPTER 1 Introduction 1-1
Overview 1-1
Component Locations 1-3
CHAPTER 2 Waterside Care 2-1
Water requirements - steam boilers 2-1
Water requirements - hot water boilers 2-2
Water Treatment 2-4
Cleaning 2-5
Boil-Out of a New Unit 2-6
Washing Out 2-8
Blowdown - Steam Boilers 2-9
Periodic Inspection 2-12
Preparation for Extended Layup 2-13
CHAPTER 3 Preparations for Startup 3-1
Pre-Startup Adjustments 3-1
Burner Operating Controls: General 3-2
Control Checks 3-5
Low Water Cutoff Devices: Steam and Hot Water 3-6
Combustion Air Proving Switch 3-6
Atomizing Air Proving Switch 3-6
Gas Pilot Flame Adjustment 3-7
Gas Pressure and Flow Information 3-8
Adjusting Combustion 3-12
Linkage Settings (optional single-point systems) 3-12
Low Gas Pressure Switch 3-19
High Gas Pressure Switch 3-20
Burner Drawer Adjustment 3-20
Oil Drawer Switch 3-21
CHAPTER 4 Startup and Operation 4-1
Sequence of Operation 4-1
Flame Loss Sequence 4-4
General Preparation for Startup: All Fuels 4-6
Control Settings: Steam and Hot Water 4-7
Gas Pilot 4-7
Atomizing Air 4-7
Firing Preparations for No. 2 Oil (Series 100, 200) 4-9
Firing Preparations for Gas (Series 200, 700) 4-11
Startup, Operating, and Shutdown: All Fuels 4-12
Control Operational Checks 4-14
Troubleshooting 4-15
Emergency Shutdown 4-19

CHAPTER 5 Inspection and Maintenance 5-1
Periodic Inspection 5-2
Fireside Cleaning 5-3
Water Level Controls 5-3
Water Gauge Glass 5-4
Electrical Controls 5-5
Flame Safety Control 5-5
Removing Burner Drawer 5-7
Oil Burner Maintenance 5-7
Gas Burner Maintenance 5-9
Motorized Gas Valve 5-10
Solenoid Valves 5-10
Air Control Damper 5-10
Fan/Motor Cassette Removal 5-11
IFGR Inspection and Adjustment 5-12
Fan/Motor Cassette Replacement 5-13
Safety Valves 5-14
Fuel Oil Metering Valve 5-15
Air Pump and Lubricating System 5-17
Refractory 5-21
Front and Rear Access 5-26
Lubrication 5-28
Combustion Adjustments 5-28
Linkage Systems 5-29
CHAPTER 6 Parts 6-1
Burner Assembly 30 PPM/60 PPM/Uncontrolled Emissions 6-2
Arch Brick and Liner Tile 6-5
Front Head 6-6
Blower Cassette 6-8
Modbus Actuators (parallel positioning) 6-9
Gas Train 6-12
Light Oil Components 6-13
Low Water Cutoff 6-15
Auxiliary Low Water Cutoff 6-16
Pressure Controls, Steam 6-17
Temperature Controls, Hot Water 6-18
Rear Head 6-19

750-392
CBEX-DE
1-1
CHAPTER 1 Introduction
1.1 — Overview
The CBEX-DE boiler is a packaged firetube boiler of welded steel construction and consists of a pressure vessel,
burner, burner controls, forced draft fan, air compressor for oil atomization, oil pump, refractory, and boiler trim
supplied according to customer’s request.
Like all CBEX boilers, the CBEX-DE features spiral tubes for enhanced heat transfer. Other features include:
•30 ppm NOx standard
•Hinged or davited insulated rear door with sight port
FIGURE 1-1. CBEX-DE cutaway view

Introduction
1-2 750-392
CBEX -DE
The CBEX-DE is a 2-pass dry-back design. The flame originates in the furnace. As the combustion gases travel
down the furnace and through the firetubes, heat from the flame and combustion gases is transferred to the
water to generate steam.
For lower emissions the CBEX-DE firetube boiler line is designed to incorporate induced Flue Gas Recirculation
(FGR). FGR may be used when firing either natural gas and/or light oil.
The FGR system mixes a portion of the relatively cool flue gas from the exit of the second-pass tubes with the
incoming combustion air to reduce the furnace flame temperature, thereby reducing NOx emissions. In this
approach, the combustion air fan handles both the combustion air and the recirculated flue gases. Carbon mon-
oxide (CO) emissions also tend to be lower due to increased turbulence caused by the addition of the flue gases
into the combustion air stream.
The low emission design can affect the selection of the combustion air fan, motor, burner, and other components.
Several different system configurations are available, depending on the requirements for NOx emissions and the
fuels used. All systems use similar primary components, but fan and motor sizes as well as the FGR damper may
differ.
Installation should conform to state and local codes. Prior to installation, the proper authorities having jurisdic-
tion are to be consulted, permits obtained, etc.
CBEX-DE boilers offer compliance with multiple insurers’ requirements. Equipment provided may vary depending
on insurance.
Steam boilers are built for a specific design pressure, which is the pressure used in calculating the minimum per-
missible thickness or physical characteristics of the pressure vessel components. Typically, the safety valves are
set at or below design pressure.
Care taken in placing the pressure vessel into initial service is vital. The waterside of new boilers and new or
remodeled steam or hot water systems may contain oil, grease, or other foreign matter. Waterside care will con-
tinue to be important throughout the lifetime of the boiler. A boilout method for new boilers, as well as general
waterside care information, can be found in Chapter 2.
1.1.1 — Construction
Steam boilers designed for 15 psig and hot water boilers designed for 250º F at 125 psi or less are constructed
in accordance with Section IV, Heating Boilers, of ASME Code.
Steam boilers designed for operating pressures exceeding 15 psig are constructed in accordance with Section I,
Power Boilers, of the ASME Code. Hot water boilers designed for operating temperatures above 250º F or 125
psi are likewise built to Section I of the ASME Code.

750-392
CBEX-DE
1-3
Component Locations
1.2 — Component Locations
FIGURE 1-2. Boiler front view (67” boiler - configurations may vary)
1. Blower assembly
2. Feedwater piping
3. Main gas train
4. Burner drawer
5. Oil system
6. Aux low water cutoff
1
2
3
4
5
6
FIGURE 1-3. Boiler side view (67” boiler - configurations may vary)
1
7
8
9
10
11
12
13
7. Control panel/entrance panel
8. Low water cutoff
9. Pressure controls
10. Safety valves
11. Oil supply piping
12. Air compressor
13. Bottom blowdown piping

Introduction
1-4 750-392
CBEX -DE
1.2.1 — Blower assembly
The blower assembly, also called the cassette,
comprises the fan and motor and can be removed
as a unit from the front of the boiler without open-
ing the front door. The front davit arm is used to
support the blower cassette during removal.
1.2.2 — Feedwater piping
Feedwater piping configurations can vary. A typical configuration is shown below, comprising three-valve bypass
piping with strainer and a modulating feedwater valve.
FIGURE 1-4. Fan/motor cassette
FIGURE 1-5. Feedwater piping

750-392
CBEX-DE
1-5
Component Locations
1.2.3 — Main gas train
Depending upon the requirements of the insurance carrier or other governing agencies, the gas train may consist
of some or all of the following items.
1. Shutoff Cocks: For manually opening and closing the main fuel gas supply downstream of the main gas line
pressure regulator. A second shutoff cock, downstream of the main gas valve(s), is installed to provide a
means of shutting off the gas line whenever a test is made for leakage across the main gas valve.
2. Main Gas Valve: Double body safety shutoff valve. Electrically actuated valves open simultaneously to admit
gas to the burner. The downstream valve is equipped with a with a regulating actuator and a proof of closure
switch that is connected to the pre-ignition interlock circuit.
3. Main Gas Vent Valve (if required): A normally open solenoid valve installed between the two main gas valves
to vent gas to the atmosphere, should any be present in the main gas line when the gas valves are deener-
gized. The vent valve closes when the gas valves are energized.
4. Low Gas Pressure Switch: A pressure-actuated switch; closed whenever main gas line pressure is above a pre-
selected pressure. Should the pressure drop below the setting, the switch contacts open a circuit causing the
main gas valve(s) to close, or prevent the burner from starting. The switch is usually equipped with a device
that must be manually reset after being tripped.
5. High Gas Pressure Switch: A pressure actuated switch; closed whenever main gas line pressure is below a
preselected pressure. Should the pressure rise above the setting, the switch contacts will open a circuit caus-
ing the main gas valve(s) to close, or prevent the burner from starting. The switch is usually equipped with a
device that must be manually reset after being tripped.
6. Test Cocks: The body of the gas valve has 1/4-inch NPT fittings for pressure test connection.
7. Butterfly Gas Valve (not shown): The pivoted disc in the valve is directly driven by a servo motor actuator to
regulate the rate of gas flow to the burner. In optional 700-800 HP single point systems, the valve is driven by
the modulating motor through connecting linkage.
FIGURE 1-6. Main gas train
1
1
2
45
6

Introduction
1-6 750-392
CBEX -DE
1.2.4 — Pilot train
1. Gas Pilot Valve: A solenoid valve that opens during the ignition period to admit fuel to the pilot. It closes after
main flame is established. The sequence of energizing and de-energizing is controlled by the programming
relay. A second gas pilot valve may be required by insurance regulations.
2. Gas Pilot Shutoff Cock: For manually opening or closing the gas supply to gas pilot valve.
3. Gas Pressure Gauge: Indicates gas pressure to pilot.
4. Gas Pressure Regulator: Reduces incoming gas pressure to suit the pilot.
1.2.5 — Burner drawer
The burner is a nozzle-mixing orifice design with interrupted gas pilot. Burners equipped for oil use a low pres-
sure, air-atomized oil system.
FIGURE 1-7. Pilot train
1
2
3
4
FIGURE 1-8. Burner drawer
GAS HOUSING
BURNER SUPPORT
BURNER DRAWER