The 4838 Temperature Controller has been added to the line of Parr Controllers. This compact controller is intended to control the temperature in our extensive line of non-stirred pressure vessels. No provision is made for the current or future expansion to control motor stirring speeds or actuate cooling water.
The 4838 contains the same Temperature Control Module used in the 4848 Controller and provides identical control and communications capabilities. The high low heater feature (full or half power) as well as the lock out relay and reset for over temperature protection are also included.
The 4838 Controller can be enhanced with the addition of either a Pressure Display Module or a High Temperature Cut Off Module or an External Temperature Limit Module.
4838 Temperature Controller
Modular Design
A total of seven different modules are offered for the 4838 Temperature Controller. One extra expansion module in addition to the primary temperature control can be installed in the 4838 Temperature Controller. The user can select either the Tachometer Display Module or the Motor Control Module. This either/ or option also applies to the High Temperature Cut Off and External Temperature Limit Modules.
Please note that the 4838 Temperature Controller cannot be equipped with stirring control or the modules related to stirring. Users desiring this should consider the 4848 Reactor Controller.
1. Temperature Control Module (TCM)
The temperature control module can accept either thermocouples or RTD temperature sensors. It has three outputs that are used for heating and cooling control and for alarm actuated heater cut off. The control function is a full proportional, integral and derivative (PID) control with auto-tune capabilities.
The controller provides ramp and soak programming with up to 49 segments.
The temperature in the reactor is transmitted to and displayed on the PC on a continual basis.
2. Pressure Display Module (PDM)
The pressure monitoring module is set up to accept its input from a pressure transducer mounted on the reactor or attached accessory. It can be set to accept a wide variety of operating ranges. Operating pressures are transmitted continuously to the PC. These modules are available calibrated in either psi or bar. In most applications, pressures are controlled by either a forward or back pressure regulator. The output from the pressure monitoring module is connected to the alarm relay to shut off power to the heater if the high pressure limit set by the operator is reached during operation.
3A. High Temperature Cut Off Module (HTM)
The high temperature cut off module or limit controller augments the operation of the main control module. Its redundant sensor can be mounted either internally or externally to the reactor. The primary output of the module is wired to activate the lock out relay in order to provide safety shutdown should the reactor reach an unsafe temperature.
3B. External Temperature Limit Module (ETLM)
This configuration uses the same aforementioned HTM Module with its sensor mounted in such a way to monitor the reactor’s outside wall temperature. The primary output of this module is used to limit the external temperature of the reactor. This is done by interrupting the control signal from the main temperature controller when the external temperature exceeds a predetermined value.
The secondary output of this module is used to activate the lock out relay if the outside wall temperature exceeds a preset unsafe temperature. The use of this module provides and effective alternative to cascade control, offering improved temperature regulation in systems with large thermal lags, such as those found in non-stirred reactors or systems that use PTFE liners, as well as systems where the reactants have low heat capacities, such as gas phase reactions.
Communications Software
Software is provided with each 4838 Controller to provide bidirectional communications between the controller and an attached PC. All operating set points and control parameters can be sent from the PC to all of the operating modules installed in the 4838 Controller. All data gathered by the modules of the 4838 is transferred to the PC for display and logging.
Free ParrCom software included with the 4838 (A1925E4 RS-485 to USB Conversion cable required for operation)
Free software is included with each 4838 Controller for simple logging processes (A1925E4 RS-485 to USB conversion cable required). For users requiring a true human-machine interface with the ability to change settings and log multiple variables, the A3504HC SpecView package is recommended.
