BDF – Working End & Forehearths

BDF conditioning glass technology is completely automated and controllable by scada which has been developed to align itself with Industry 4.0 philosophy.

BDF designs have a typical shape, which offer advantages compared with conventional working ends and forehearths. The superstructure design in combination with the cooling and gas heating system provides an efficient possibility to influence the glass temperature prior to entering the forehearths.

The gas heating system is divided in control zones, with PID working temperature control loops. Manifold burners are applied for the gas heating system. The gas and combustion air supply and the air/gas control equipment is assembled on free-standing stations.

Combustion air is provided by radial fans (one of them as stand-by) and is regulated to supply for all zones. The gas supply station also has capacity to supply the conditioning area. The cooling air flow is automatically regulated by frequency speed controlled fan motor. Temperature is measured in the cooling zones with single thermocouples, whilst in the equalizing zones three triplex thermocouples are installed. This arrangement of thermocouples create a 9-point grid measurement, which provides a matrix to determine the thermal homogeneity of the glass in this crucial stage.
Often the heat energy to be extracted from the glass to deliver the required gob temperature is much higher than what is possible to achieve from the refractory heat loss and so it becomes necessary to provide additional cooling.

A forced convection cooling system is used to cool air through the forehearth superstructure.
Longitudinal centre line cooling, efficiently removes heat from the hot centre of the molten glass without adversely affecting side glass temperatures, and this method uses a relatively small volume of cooling air.

The roof cover design has been developed in order to maximize the refractory surface exposed to the glass in the forehearth centre.

This shape allows for increased heat exchange between the glass and the roof since the glass is exposed to a colder large refractory surface.

This application is fitted with openings in the superstructure roof blocks, to allow for the combustion waste gases exhaust.