Boiler plant construction
Given also that micro-processor based controls are now an almost universal feature on new packaged-boilers, the traditional boiler attendant is becoming an endangered species in small to medium sized plants supplying process steam. At the very least, their role has changed from that of direct, hands-on operation to one of supervising the operation of the BCS and performing tasks that ensure its continuing integrity and compliance with the requirements of boiler codes and standards.Boiler operation has evolved to the point that in many jurisdictions, fully attended operation is unusual outside of large, complex plants. The exceptions are large power utilities, chemical recovery boilers and similar integrated processes where the boiler is a key component.what is a limited-attendance boiler?The Limited-Attendance mode of operation allows for periodic checking of the boiler at set minimum intervals rather than continuous attendance. A key feature of limited-attendance boilers is that they may at any time be brought under the control of an appropriately qualified operator and operated in the fully attended mode under continuous supervision.Many older packaged boilers and those that have been upgraded from attended status are classified as limited-attendance simply because their control systems do not achieve the same standards of integrity and reliability as do modern micro-processor based systems. Many also include provision for manual intervention which in most jurisdictions disqualifies them for consideration for unattended status.What is an unattended boiler?An Unattended Boiler is essentially a fully automatic boiler that operates under the continuous supervision and control of a sophisticated, micro-processor based, BCS. The BCS controls the entire boiler function including the energy input management system (on oil and gas-fired boilers commonly known as the "Burner Management System" or, BMS), the water level management system, the alarm system, the pressure controls, trip devices, all instruments and circuitry.
A key feature of this type of boiler is that in most jurisdictions boiler codes and standards dictate that a boiler that is classified as unattended must be under the continuous supervision and control of the BCS at all times that it is in service. The unattended boiler may only be operated in unattended mode. It may not be operated in attended mode under any circumstances even for brief periods and even if a qualified operator is available. In practice, the BCS employed on an unattended boiler has no provision for manual operation. In the event of a control system fault or a potentially unsafe condition, the BCS will shut down the boiler and lock-out the energy input system. It will prevent a boiler restart until such time that the control system fault has been repaired or, the potentially unsafe condition has been addressed and all of the BCS inputs indicate that the boiler is in a safe condition.The BCS is equipped with some means of recording all major events that cause the alarms to activate. On early unattended boilers this was typically a simple printer that recorded such events on a line-by-line basis. More modern systems however, store the information in the onboard micro-processor memory for an extended period. That is, they may only be operated in unattended mode. giving customers a 2-year guarantee on the labour performed as well as a no obligation estimate. Biomass boilers, Carbon filters, Boiler plant construction