The EDl00l system was developed by Elite Technologies to enable students to practice notions in instrumentation, regulation, control and automation of continuous processes. It allows students to become familiar with real processes by allowing them to connect the different components of the system, to initiate different calibrations and to set up tuning parameters. The strategies can be modified and the system also allows cascade control, feedforward control and other control strategies.
The open-modular concept allows students to connect the system to other equipment such as programmable logic controller, process controls, PID controllers and distribute control systems (DCS).
The unit is mounted, inspected and delivered ready to use. Different educational aspects are taken into consideration during the design, as well as ensuring that the final assembly will be easy to move, sturdy, attractive, safe, flexible, and versatile.
A laboratory manual containing a series of proven experiments comes with each system.
The design was done in close collaboration with technical college professors and technicians from industries. The choice of components was made in accordance to today’s industrial reality, with emphasis on sturdiness and precision, as well as on the choice of manufacturer.
The choice of processes, loops and their static and dynamic characteristics (time constants, time delays, process gains) were all made carefully.
The system was designed with 4 loops:
- Pressure (the same transmitter is used for each loop)
- Temperature (optional).
Protection and alarms (PLC)
A programmable logic controller, connected to sensors, ensures the security of the system and generates appropriate alarms. The alarm sequences are identical to those found in the industry. Additional inputs (dry contacts) allow the user to include other signals in the alarm system.
Sensors allow a sequence of alarms and protections, sequential control as well as batch control:
- Low level float
- Controller contacts
- Additional level switch (optional)
- Pressure switch (optional)
The system consists of pumping water into a reservoir, and then recycling it. Using a very quiet pump, water from a reserve is pumped into a reservoir (50 inches) by way of a control valve, which controls the level if the system is in a single loop, or the flow if the loops are in cascade control. The output of this reservoir discharges into a reserve and returns to the pump. This reserve contains a heating element (temperature loop).
The security system will cut off the heating element if the circulation pump is functioning. This pump is protected by a low-level float. Two configur-able alarms are also available to students.
This system was designed to be used in a laboratory as well as in the classroom. Requiring only an electrical supply of 120 Vca and an air supply of 20 lbs/inch2 or more (a reservoir of compressed air is offered as an option, allowing an autonomy of about one hour when the positionner is not being used).
Set on wheels and not too large (6 feet high by 3 feet wide), it is easily moved around and easily stored. Recycling the same water, it does not require access to a drain or water supply in order to work.
Its white facade, on which the process controllers and controls are mounted, can be used as a drawing board, allowing the student to trace (using a dry ink pen) the connections between the different components. The ISA symbolic drawings on the front panel represent the components mounted behind the panel (ISA 5.1 to 5.5).
The component connections are made from the back by using cables with rapid connectors. The different loops are not permanently connected, allowing various combinations of the components.
Summary of practical experiments
Contains 4 loops (flow/level/temperature/pressure), allowing the students to become familiar with:
- Low measurement with differential elements,
- Level measurement by hydrostatic pressure
- Temperature measurement with resistance temperature detector (RTD),
- Final control devices, valves etc.
- Standard signals and converters:
- 4-20 mAcd,
- 3-15 PSI,
- Time proportioning
- Control configuration and data acquisition,
- Standard ISA symbolization,
- Control modes: ON/OFF, P, PI, PID, Tuning
- Start-up of control loop,
- Single and cascade loops,
- Batch controls,
- Supervisory control and data acquisition (SCADA).
It is possible to control a continuous process and to build independent sequences with a PLC, for example:
- Alarm sequence,
- Protection system allowing security between components (interlock),
- Starting and stopping sequences, with or without feedback.
- ON/OFF pump control on High/Low level,
- Sequential control (times or conditions).
Supplied laboratory experiments
Twenty (20) experiments are supplied with each system, covering the following subjects:
- Process control,
- Automatic control,
- Process measurement,
- Final control devices,
- Batch control,
- Programmable control systems, sequential control,
- Industrial processes
Option #1 (level loop)
The level transmitter measures the hydrostatic pressure at the bottom of the tank.
- Level transmitter,
- PID controller
Option # 2 (temperature loop)
- RTD Pt100
- Temperature transmitter
- PID controller
- Electric heater
- Solid state relay
- Temperature switch (capillary bulb)
- Blower (to ensure good process response)
Option # 3 (communication)
- RS-422 or RS485 converter
Option # 4 (multimeter)
Option # 5 (level switch)
Option # 6 (pressure switch)
- Adjustable pressure switch
Option # 7 (ManMachineInterface)
Option # 8 (training)
Option # 9 (air tank)
An air tank ensures one hour of autonomy (without an air compressor).
Option # 10 (aluminum base for air tank)
Option # 11 (feedforward)
A Venturi tube and a differential pressure transmitter are added to measure the tank outflow.
- Venturi tube
- Flow transmitter (dP)
- Wood box with foam
Option # 13 Low noise portable air compressor