The Multi-Process Station, Model 3505, consists of a 20-cm (8-inch) diameter, 92-cm (36-inch) high Plexiglass cylinder, a 10-cm (4-inch) diameter inner column for dual volume process characteristic, a pump, a diaphragm-actuated control valve, two pipe-mounted differential pressure (D/P) transmitters, and a current-to-pressure (I/P) converter. A microprocessor-based controller, a variable frequency AC drive, a dual-pen strip chart recorder, and two alarm lamps are also mounted on the main panel. A regulator needle valve controls air flow to a bubbler pipe for level measurement. In addition, at the base of the level column are two valved taps that permit connection of the D/P cell or optional manometers. A low-pressure gauge and a compound-pressure gauge are mounted on the side of the control cabinet. A pressure cap on the level process tank permits level controls of a pressurized vessel. A wet leg standpipe is also provided.
All process piping is made of clear thermoplastic (PVC). Two 30-cm (12-inch) headers allow insertion of flow measurement devices on both the inflow and outflow of the level process tank. The station includes a rotameter flow indicator in series with the process piping, and a Venturi flow-element. Flow control can be achieved by either using the pump running at fixed speed and the pneumatic control valve, or by bypassing the control valve and operating the pump at variable speed using the variable frequency AC drive.
The level column can be bypassed to operate a fast process flow loop. Pressure control is achieved the same way as flow control, with piping throttled downstream of the variable area flow meter. Coupling unions allow the Multi-Process Station to be directly coupled to other stations to achieve more advanced interactive control loops such as temperature, pH, and ratio control. Pressure taps are provided on the system piping to permit measurement of pressure drops around the system and to evaluate the system performance thoroughly.
Supporting courseware comprises 22 laboratory exercises, written specifically for the Multi-Process Station. Completion of the courseware also requires a digital multimeter and a DC process signal calibrator. These devices are available on the Lab-Volt Calibration Bench, Model 3550.
|| All required gauges, switches, manometers, patchcords, hoses, and flow elements are included
Fault insertion capability
Transparent piping and valves for student observation of system operation
Interconnectable workstations to allow training in complex systems
Realistic process response
Quick-disconnect fittings for a rapid system configuration
Multi-element and ratio control capability
Patch-connected control devices to permit alternate control schemes and flexibility in incorporating new technology as it is developed
Standard industrial instrumentation