What Are the Different Types of Chemical Process Control?

Chemical process control safely automates a process, or series of operations, for a chemical product. There are many types of process controls, and most are unique to a specific manufacturing process of engineering. The main purposes of chemical process control are making and moving chemical products, like sulfuric acid. The operations are commonly divided into five main categories and are controlled with three options. All steps in a chemical control process also behave continuously or discretely, which means the operation can either be always flowing or done in batches.

The most important characteristic of chemical control process is whether it is discrete or continuous. All the calculations for operations, measurements, and controls are based on chemical flow. Predicting continuous flow is difficult and requires engineering skill, but discrete operations are more common. Baking a cake is done in discrete steps, normally one cake at a time, but a factory may choose a continuous process. By using a much larger oven and a conveyor belt, it becomes possible to automate a continuous flow of cakes.

It is often useful for an operation to perform at least one of the five main tasks of chemical process control. These tasks are heating, evaporating, distilling, drying, and reacting. Any setup has a variety of engineering options for performing these operations. For example, drying can be done with air, heat, and other chemical options. The operations are used in combinations with process measurements.

Process control is accomplished in three different ways: feedback, feed-forward, and computer controls. Feedback process control involves setting a point for a measurement and having the system stop when that point is reached. Feed-forward means the set point causes the system to start, while computers have several options of digital controls. Power plants commonly use feedback controls for temperature control, feed-forward controls for chemical flow, and computer controls for monitoring the systems. The central command room is covered with instruments and digital controls in many chemical plants, all for the purpose of process control.

Taking measurements for control processes has the most variety when discussing types of chemical process control. The combination of operations, flow types, measurement tools, and control systems all contribute to determining the final type of chemical process control. Engineers use recorded data and math tools to predict the design of a chemical process control and determine ways to improve those already in use.