Figure 1-20.Airflow diagram.
(3) which, if it sights no flame, reacts to cause a switching
action that results in shutting down the burner.
FLAME FAILURE AND OPERATIONAL
Frequently on fully automatic boilers, you will find
an electronic type of device provided for the control of
flame failure. The device provides automatic start and
operation of the main burner equipment. Some controls
are designed to close all fuel valves, shut down the burner
equipment within 4 seconds after a flame failure. and
actuate an alarm. Some controls also create a safety
shutdown within 4 seconds after de-energization of
ignition equipment when the main burner flame is not
properly established or fails during the normal starting
sequence. These controls must create a safety shutdown
when the pilot flame is not established and confirmed
within 7 seconds after lighting. A safety shutdown
requires manual reset before operation can be resumed
and prevents recycling of the burner equipment.
What is the process of maintaining a difference of
pressure between two points in a system
The flow of the air-fuel mixture supplied to the
furnace is regulated by steam demand. What is this
The rate at which combustion air is delivered to the
blower can be changed by throttling what device?
Once a safety shutdown of a boiler has occurred,
what action must be taken before operations can
INSTRUMENTS AND METERS
Learning Objective: Identify the instruments and meters
used on boilers and describe the function of each.
A pressure gauge is essential for safe operation of a
boiler plant. However, the use of additional instruments.