Enhancing BMS Safety with the use of PLC-based Controls

Combustion equipment safety is essential for the daily operation of facilities and safety of plant personnel. Safety protocols and mechanisms in industrial plants have improved drastically in the last century, but incidents still occur far too frequently. Because boiler systems are inherently dangerous, safety must be factored into the design of not just the boiler, but also the burner, combustion control, and the overall operation of the system.

The burner management system (BMS) is just one of many safety devices built into a boiler system, designed to control the combustion process from beginning to end in a safe and reliable manner. It monitors high and low gas pressure, the combustion air fan, combustion air, and water levels, in addition to monitoring safety devices and controlling the sequence of lighting the burner. If any issues arise related to pressure or water level, it will initiate closure of the shut-off valves. To automate these processes, PLC-based controls are often used as a BMS. PLC based BMS gives you much more flexibility, the ability to use analog input signals as limits, limit voting and the versatility to have almost unlimited safety limits.

A Programmable Logic Controller (PLC) is a robust computer utilized for industrial automation. Although a PLC doesn’t physically look like a typical computer, it incorporates the very same technology seen in computers and smart devices that we use every day. The PLC receives information from connected sensors or input devices, processes the data, and triggers outputs based on pre-programmed parameters. It consists of a power supply, a CPU (central processing unit), input and output cards, and communication cards. A programming device (often a laptop computer) is utilized for writing programs into the PLC and HMI (human machine interface) which provides a visual model of the system as a whole.

Compared to traditional technologies, a PLC-based system is easier to troubleshoot, more reliable, more cost-effective, and much more versatile. In addition, PLC-based controls provide added levels of safety for the burner management system and overall operation of your boiler. PLCs are built in compliance with NFPA 85 and SIL2 requirements at minimum and can be configured to meet SIL3 standards as well. Therefore, we are seeing boiler control panels being built or updated to PLC-based systems more than ever.

Pacific Combustion Engineering has extensive knowledge and experience in the design, build, and programming of PLC-based combustion control systems. If you are in the market for an upgrade or brand-new panel that incorporates PLC, give us a call and we will design a system that fits your unique process needs.