Wittmann: Small Temperature Controller for Demanding Applications

At Fakuma 2005 Wittmann (www.wittmann-robot.com) presented a new development from its „Water & Cooling“ product range: the small microprocessor controlled temperature controller Tempro Plus Direct 120 “Direct Injection” which was specifically designed for small to medium range molding machines, as well as applications requiring high cooling capacity.

The new temperature controller comes in a very compact package with a pump flow rate of up to 35 liters and a maximum pressure of 5.5 bar. The heating capacity reaches 6 kW with low-watt density incoloy heating elements. The completely non-ferrous construction of the unit eliminates problems associated with rust and wetted component degradation common in ferrous units. The unit is constructed with a rugged metal frame and foamed ABS side panels.

Advert

The units are equipped as a standard with integrated pressure monitoring and exact water flow measurement. By means of two pressure sensors both process and return line pressures are measured, the differential is then used to determine the water flow rate. Set points can be set individually for the flow rate, the process and the return line pressure. In the event these set points are actually exceeded, an alarm message can be activated.

As the name implies, the temperature controller model Tempro Plus Direct 120 is equipped with direct cooling. If cooling is activated, water is purged from the process circuit and cooling water is introduced into the system. Compared to an indirectly cooled unit, the cooling capacity is increased by over 100%.

A special feature of the unit is to offer an unlimited purging volume in case of mold evacuation or purging. To start the purging mode, the control automatically reverses the pump direction and through a pneumatically actuated 3-way valve, the water is directed into the cooling line. This allows the unlimited purging capacity of the temperature controller.

A user-friendly, self-optimizing microprocessor control is also standard. The controller monitors the temperature every 10 seconds to allow for fast response and automatic temperature adjustment. The unit operates with PID control based on several different input parameters. This allows for a very steep heat up curve and extremely short balancing out once the set point is reached. The unit can maintain a temperature of up to 120 °C (250 °F) in its standard positive pumping mode. An audible alarm buzzer sounds to notify the operator if any errors occur. An operating hour counter indicates when routine maintenance is either required or recommended.

Wittmann Robot Systeme GmbH, Wien, Österreich

back to news list