Design of a low cost trainer for flow control

Process control laboratories in most colleges and universities include a single process trainer for control exercises in temperature, level, flow and pressure. Single trainers are present because of the size and cost of the systems; however, the use of single systems makes it difficult to use small laboratory teams without reducing the enrolment limit placed on the laboratory section. Ideally, the process laboratory should have multiple trainers in at least two of the four primary process variables to learn the basics of process control. Then the students could move to the larger more robust systems to study control of a large industrial process. This paper describes a low cost flow trainer that was developed with the support of a National Science Foundation (NSF) Instructional Laboratory Instrumentation (ILI) grant to permit training in basic control concepts to multiple student teams. Construction cost for the flow system is less than $500 and all of the components are available off-the-shelf from a number of industrial sources. The system can be controlled by any single-loop process controller, a programmable logic controller, or a microcomputer using a control software product, such as Lab View. The system has been tested at several colleges and universities including Trident Technical College with excellent results. This paper describes the system design, construction requirements, example laboratory exercises and test results.