Edmund Erdmann - The Newest Generation of the Horizontal Tempering Plants for Flat Glass VITROMOD®

Constant temperature distribution over the entire batch surface (+/-5°C).

2. Different heating zones within the furnace each with single heating control.

3. Fastest temperature modifications within the furnace through non-covered heating elements.

4. Significant shorter heating times (up to 25 %) by means of a patented EEE-Jetstream Convection System.

5. Trouble-free processing of all Low-E glasses suitable for tempering, soft coatings inclusive.

6. Constant fracture pattern and excellent plane surface.

7. Maximum profitability with lowest maintenance operating expense by means of strong machine construction, the use of reliable components and modular construction.

8. Short assembly times by means of the application of pre-tested components and on the basis of the modular construction.

9. Considerable lower average electric power consumption during operation in comparison to systems of our competitors, whose heat-storage-systems use current all the time. EEE-VITROMOD® however requires current only with thermal fluctuations, in order to re-establish the predetermined desired temperature values.

10. Improved performance of the tempering station by means of
- big exhaust air-cross-sections
- an optimised jet-form
- constant pressure-circumstances over the entire working width
- application of speed controlled fans

11. Utmost production security and reliability of the installation by means of
- application of roller conveyor drives with maintenance-free 3-phases induction motors
- application of durable heating elements
- readjusting of chains and tapes become redundant
- lubricant free functioning of the roller conveyors
- the PJ 40 automation system with its legendary stability and resilience in long-term application under most extreme conditions
- modular construction

The OPERATOR plus is the improved version of EEE's successful OPERATOR system, which among other things offers the following new performances:
- sophisticated operator-identification via password
- user-defined derivative process parameters with process- and desired values
- vertical integration in ERP-systems (Enterprise Resource Management), for example plant data processors

Jetstream

During the heating of glass in a furnace for tempering flat glass sheets, the heat transfer takes place by means of two mechanisms. On one side the glass is supplied by heat (by means of radiation) from above and below, on the other side there is an additional heat flow because of the contact between glass and ceramic rollers (from the rollers onto the glass [conduction]). The best way of heat transfer is to realize it in the same manner from above and below in order to preserve the plane surface of the sheet. With clear float glass this is generally possible.

Glass which is coated with a reflecting surface represents a problem in this context, because the heat will be reflected by the coating to the top. (Normally this is desired by the consumer.) Here the heat transfer by means of radiation from above is more or less blocked.

Remedial action can be taken by heat transfer with convection. Generally air jets are assembled for this in the upper part of the furnace, which shall set the warm air in motion. Weak points of conventional convection equipment are on one hand the cold ambient air temperature, which is blown into the furnace, on the other hand the very high pressures (sometimes more than 10 bar) which are necessary, in order to achieve a satisfactory convection effect. Both reduce the technological as well as the economical efficiency of the tempering line.

By using the Jetstream technology developed by Edmund Erdmann the disadvantages of the conventional convection are no longer existing.

The way of function of the Jetstream is based on the acceleration of furnace air by means of a low air pressure created by a secondary air flow. For this with the help of an injection jet a small quantity of air is blown in very near behind the confusor of a Jetstream which - because of the arising low air pressure - sucks in a large quantity of heated furnace air out of the confusor. The potential relation of secondary and furnace air can behave hereby until 1:40.

By the application of this technology the supply pressure can be reduced to 1 bar. By using the integrated mixer the secondary and the furnace air are mixed, the temperature influence of the furnace atmosphere will be minimized compared with the conventional blowing of the cold ambient air.

By the intensified effect of the Jetstream it is possible to circulate the furnace atmosphere once a second.

Operating with the Jetstream means an optimum of the relation between resource which has been used up and efficiency.