What does Process Control mean?
Humans have been looking for an easier, safer, and more efficient way to do things since…well, since forever. This doesn’t mean we as a species are getting lazier; it just means we are freeing up time to do more important things. Process controls are a way that we make various menial tasks automated, but what does that really entail? We’ll try and define this concept, give an example, and see just how prevalent this notion is.
Our early ancestors developed tools to help hunt, cook, and survive, and we are still progressing our technology for those same tasks today. We may no longer hunt, but we have animal husbandry. We do our cooking these days in microwaves and convection ovens rather than by campfire. And we are capable of constructing an incredible variety of safe and comfortable living quarters, no more living in a cave. There is a natural progression for us to create tools to help us throughout modern life. They could be literal tools, like a screwdriver, but they could also be inventions, like computers, or even concepts, like the scientific method.
Figure 1: A VIP-9000 and a PX61
Here at Enercorp, we specialize in manufacturing instruments that sense temperature, pressure, moisture, humidity, and electrical current. These sorts of sensors can act as data collectors for the automated world of process controls, a modern type of invention where we harness technology to help observe, modify, and operate the numerous activities that go on all around us. If you’re curious to see some of these sensors, head on over to our pressure transmitters or our pneumatic VIP-9000s controllers. Let’s nail down this concept; what is Process Control?
The Definition of Process Control
The act of “Process Control” is the monitoring and influencing of an activity to maintain a desired output. Now that is an incredibly simplified definition, the essence of Process Control boiled down to the most basic idea. We’ll use an example to help flesh out that explanation.
Imagine some people inside a room that gradually loses heat and gets cold. We don’t want the people inside to freeze, so we’ll heat it with a furnace. When the room is cold, someone turns on the furnace to let warm air into the room. When the room is at a comfortable temperature, someone then turns off the furnace to keep the room from getting too hot.
Applying a Process Control
Having someone turn on and off a furnace is an easy solution to keeping the room at a desirable temperature. But is that the best way to perform this task? This is an ideal situation in which we’ll apply a process control to automate the operation and make it more efficient. We’ll do this by adding a thermostat to our example.
Imagine the same room that gradually gets cold. However, now our thermostat senses when the room is cold and signals the furnace to turn on. Once the room is at a comfortable temperature, the thermostat signals the furnace to turn off; lest it becomes too hot.
The Benefits of Process Control
In our previous example, by adding a thermostat to our room, we have created a hypothetical process control. We haven’t changed the desired output, keeping the room at a comfortable temperature, but we have added a way to monitor and provide actions in a way without the direct involvement of a person. The process control that comes with the thermostat gives many benefits; we’ll go through those next.
1. Automation:
The menial task of turning on and off a furnace is now given to an instrument. Therefore allowing a worker to perform a more specialized task instead. Another example of this sort of automation can be found in accounting. Accountants now no longer spend their days adding and subtracting numbers. The basic tasks of arithmetic are completed by computers, freeing up time for accountants to take on other work; engage with clients on a more personal level; or perform a more in-depth analysis of the data being crunched by computers.
2. Safety:
Humans can be an inaccurate and forgetful lot, that especially goes for the guy who had to turn on and off the furnace in our example above. What would have happened if he waited too long to turn on the furnace or fell asleep? You’d have a room full of cold, grumpy people. Applying a process control to an activity can also mean making that procedure safer by taking out the “human factor.”
3. Optimization:
Let’s say our forgetful human forgot to turn off the heat when he was supposed to, or it took him a little longer to react. Now the room is warmer than necessary, and people are uncomfortably hot. Your furnace has also been running more than needed. That means you’ve wasted more fuel and caused unnecessary wear and tear on the furnace components. The process control thermostat automates the furnace and avoids these kinds of excessive costs.
What else can have a Process Control?
Process control doesn’t have to be limited to heating a room. There are an infinite amount of places and situations that are using this sort of automation, although the phrase “process control” typically means something of industrial nature. Temperature is merely one of many variables that can be measured. Other monitored processes could be air pressure, water pressure, electrical current, flow rate; or really any value that can be quantified and then have an action taken based upon that measurement.
Let’s take the example of a company that manufactures lemonade. They would use process controls to measure out specific amounts of ingredients like water, lemon juice, and sugar to obtain the desired mixture. They also could use a process control that measures the amount of product an empty bottle requires for filling. There could even be a process control that can count when 24 bottles have been placed in a box; and trigger actions like moving the full case down a conveyor belt to a delivery truck and readies an empty box to take the next 24 bottles.
Figure 2: A DCS-4000 front and back board
At Enercorp, we sell controllers that provide centralized automation to some processes. A controller is a computer that accepts information from sensors and user inputs and then performs actions. It displays measured data, such as temperature sensed from a thermometer. Then based on the options a user chooses, various signals will be sent to connected devices, allowing certain actions to take place. For example, our DCS-4000 system is used in the tobacco drying process. You can adjust various parameters through the interface board. When this is combined with data from temperature sensors; fans can turn on to circulate air; gas valves can open to provide fuel to heat a kiln; and alarms can sound if certain conditions occur; just to name a few of the possible automated signals.
We use process controls across many different industries, from nuclear power production to oil refining to office building HVAC systems. It is more than just the automation of basic tasks; it allows for efficiency and safety. Also, freeing up human labour to take on more intricate or creative tasks. At Enercorp, we custom-manufacture all of our temperature sensors, and most of what we sell ends up as part of a process control system.
