Modernization of a continuous system employing three Krantz stenter frames
In the context of "Industry 4.0", Industrielle System Technik Michael Haasner (IST) recently modernized a textile stenter frame system – one of the largest in Europe – at VSM in Hanover. The installation, manufactured in 1986 by Krantz, has a fabric holding capacity of 280 metres and extends over 2 levels. The installation as a whole comprises an infeed unit, a dwell station, a Küsters S roll padder, three Krantz textile stenter frames each with 10 compartments, three applicators, a Küsters textile calender and an automatic winding station.
The legacy DC gear motors were replaced by highly efficient servo drive technology. In addition, all contactor circuits for fan motors were replaced by frequency converter technology.
For width adjustment of the three chains in the three stenter frames, a new gear motor with absolute encoder was fitted for each dryer compartment, enabling the chain to be adjusted in each compartment within a certain tolerance range with respect to the next compartment. Using a dedicated program for the width adjustment, written by IST, the machine operator can enter the total width on the touch screens at the entry and exit and adjust it automatically.
The former control room, in which two or three employees had a full view and control of the entire system at all times, gave the visitor the impression of being on the flight deck of a spaceship.
From here, all functions and processes were controlled by means of approximately 1,400 illuminated pushbuttons, 200 switches, 400 lamps, six touch screens, three anodized aluminium product flow displays with 100 LEDs, and 30 digital displays on the control desks.
The control concept of the installation was revised by IST and equipped with the latest control technology. The entire modernized installation is now operated by a single employee.
The workstation from which the system is now operated is a desk with three 24" monitors. The parameters for the individual machines are entered and monitored at this workstation. A hard drive with a capacity of a terabyte is able to store an almost infinite number of recipes. Each recipe stored can contain up to 1,000 records and 2,000 values per record.
An additional 12 cameras monitor and display the most important points on the system on three 42" monitors.
By modernizing and optimizing the control system, IST also achieved a huge reduction in the power consumption. Measurements show that the conversion reduced the system's electrical power consumption by approximately 360 megawatt hours per year. Statistically, this corresponds to the electrical energy consumed by 120 three-person households per year.
For modernization of the system as a whole, IST installed the following hardware components:
15 PLC stations, nine touch screens, three 24" monitors, 68 frequency converters,
nine sub-distribution panels, 15 control boxes and an 18-metre-long switchgear
cabinet, complete with modem for remote maintenance.
A Siemens control system and Profinet were used for automation.
IST offers you one-stop solutions employing the latest control technology for modernization (retrofitting) of textile stenter frames from any manufacturer (Krantz, Babcock, Artos, Famatex, Monforts, Brückner).
Call or email us. We will be happy to advise you!
The IST team – at your service