Industrial Process And Controllers
The is a benchtop process control system, comprising a process unit
mounted on an ABS plinth, a electrical control console, and control
software, which can be run on any Windows PC with a spare USB port.
Process Unit:
The process is modelled on an industrial high-temperature/short-time
(HTST) pasteurisation process. In this process the product stream has to
be kept at a predetermined temperature for a minimum time, usually for
bacteriological purposes. This is effected by the use of a holding tube,
which delays the product stream, thus posing particular process control
problems and introducing the concept of ‘dead time’.
Other reasons why the HTST process is a particularly suitable basis for
teaching process control are the use of a three-stage heat exchanger
(recycle, heating and cooling) and the use of a divert valve to reject
inadequately treated product. Again these important industrial
principles pose real process control problems and help maintain the
students’ interest.
Further process control problems are illustrated by the use of two feed
tanks, with different level sensor types.
Solenoid-driven valves control the filling and emptying of these tanks.
These enable different level control strategies to be developed and
provide startup and shutdown operational sequencing capability.
The unit includes a wide range of instrumentation for temperature and
flow measurement. It also includes a conductivity sensor, enabling
simple process concentration experiments to be performed.
The Unit Comprises:
Feed system with peristaltic pump
Water heating unit with peristaltic pump
Water cooling system
Plate heat exchanger with holding tube
Flow sensor in feed line
Conductivity sensor
Four temperature sensors
Level sensor in product tank
High/low level switches in washing/reagent tank
Two-way solenoid valves for filling feed tanks and cooling water to
exchanger
Three-way solenoid valves for selecting feed tank and diverting waste
product
Connections to the electrical console
The control console provides the electrical interface and signal
conditioning for the process module. It also includes a USB interface
for a Windows computer. The process module sensor outputs can be
displayed in engineering units on an integral LED display. The outputs
are also available for external monitoring.
The drive signals to the process module can be selected as either manual
control from the front panel, control from a PC via the USB bus, on/off
control from an external sourceor analogue control from an external
source . The source signals for both pumps and the heater are
individually selectable.
Electrical faults may be introduced into any of the low-voltage
measurement or control signals by a fault emulator installed in the
electrical console. Faults may be inserted individually or in
combination to suit the student’s ability. The quick-release fittings
used throughout the process enable faults to be introduced into the
process pipework.
The Unit Comprises:
Product feed pump speed controlHeating fluid pump speed control
Heater power measurement and control
Temperature (x4), flow, level & conductivity measurement
Digital inputs/outputs (from switches/to solenoid valves)
Simultaneous connection of all signals to via 50-way IDC connector or PC via USB port
Technical Specification
Flow rate ranges: Value
Product stream: 0-480 ml/min
Washing reagent: 0-480 ml/min
Heating fluid: 0-600 ml/min
Max temperature of heating fluid: 80°C
Heat exchanger: Plate type
Feed and reagent vessel capacities: 5.7l (each)
Heating vessel capacity: 3.7l
Signal voltages: 0-5V
Level sensor range: 0-250mm
Flow sensor range: 0-500 ml/min
Temperature sensor range: 0-100°C
Industrial Process And Controllers ALTEC Laboratory Equipments and ALTEC Laboratory Instruments Tenders.