If it ain’t broke, don’t automate it?
As a card-carrying member of the control engineering community, I’ve never understood the level of disdain some industries have for automating their processes. I started my career in an industry that understood they could no longer operate their plants without a robust and effective process control system. They realized a long time ago that manual operation of an 880 MW coal-fired power plant is just not an option. After almost 10 years in the utility power industry, I switched to working on control systems for industrial manufacturing customers. To say that I was surprised at the lack of controls in manufacturing would be an understatement – I was appalled! My first project was a new multi-fuel boiler and turbo-generator for a paper mill. The bulk of our control system was focused on drum level control and fuel-air ratio control. Of course, being a paper mill, much of the fuel for the boiler was bark and other waste being burned on a grate. This meant that the whole “fuel leads, air follows” paradigm I was drilled in with utility boilers was really only in place when we were burning oil or pulverized coal in suspension. Anytime we were firing with waste fuels on the grate, we really weren’t worried about a flame out causing a boiler explosion.
That was followed with another bark boiler project with similar scope. Then I did my first paper machine with a DCS (distributed control system) and thought to myself, “Now I’ll get to do some real controls work.”
Wrong! In fact, the paper machine superintendent would come by the control room every night to see what I was doing and on the way out the door would stop and say, “Remember, I can make paper in manual.” Now, I actually did get to do some real automation and ultimately set a record in automatic, but that attitude continues to present itself 30 years later in many industries. So many of our industrial facilities are still running with many of their control loops in manual. When I ask why that is, the usual answer falls into one of two categories:
“Oh, that never worked right,” and,
“I’m waiting on maintenance to fix something.”
There are variations of course, but the answers generally fall under one of these headings.
So, why do our plant managers and area superintendants allow this to continue? The easy answer is money, but it’s rarely the whole answer. As long as managers are making their production targets, there’s little or no incentive to spend money to make it better. A change might even make things worse. That attitude is fostered by the feeling that there isn’t a way to make it better, which is exacerbated by the lack of a system champion.
I did some work not too long ago for a pharmaceutical customer, an industry that is noted for effective use of control systems, on a regenerative thermal oxidizer (RTO) that they had purchased as a turn-key installation to address an emissions problem. The RTO had been running for about five years, and the only reason they wanted me to take a look at the controls was because the neighbors of the plant were complaining about the noise the stack was making when the RTO was running. No one at the plant knew anything about how the RTO was controlled, so my job was to reverse engineer it and fix whatever was causing the problem.
Step one was to observe the problem. They started it up, and the variable speed fan went to maximum speed and the stack howled like a banshee. After digging into the PLC code that operated the RTO and its associated scrubber, it became clear that the setpoint for the fan control loop, which was designed to pull the vapors out of the manufacturing suite, was set lower than the draft the fan could create. There was never anything wrong with the control code itself. I adjusted the setpoint to something the fan could achieve, and the exhaust quit howling. As an added bonus, gas consumption was greatly reduced. In one simple step, the company started saving money by using less auxiliary fuel and less electricity.
They had operated for five years with the system just the way the original vendor had left it, untested and untuned. Why? No one owned the system, and it wasn’t until they had a project manager join them who had a background in controls that they had someone question why they couldn’t fix this problem. So ask yourself, what’s running in your plant that has no real owner? Where are you losing money because no one has the vision that things can be made better? What are you just living with because no one knows how to fix it? What are you just ignoring because you’re making your production targets? As a controls engineer, you should be able to see opportunities where you can apply your knowledge and realize real benefits.
This post was written by Bruce Brandt, PE. Bruce is a technology leader at MAVERICK Technologies, a leading system integrator providing industrial automation, strategic manufacturing, and enterprise integration services in the manufacturing and process industries. MAVERICK delivers expertise and consulting in a wide variety of areas including industrial automation controls, distributed control systems, manufacturing execution systems, operational strategy, and business process optimization. The company provides a full range of automation and controls services – ranging from industrial cyber security to HMI systems design and remote facility management. Additionally MAVERICK offers industrial and technical staffing services, placing on-site automation, instrumentation and controls engineers.