glass furnace forehearth

A simplified Forehearth design that achieves a high degree of thermal stability and cooling capability.The Sanjin Advanced Gas Fired Forehearth provides glassmakers with the increased flexibility and tonnage pull range necessary to meet rapidly changing market demands.

The Sanjin Advanced Gas Fired Forehearth provides thermal stability and cooling capability with simplified operational ease. This Forehearth has the capability to heat both the side and centre glass (as required), providing better flexibility and control of the glass conditioning process.

Key Features include:

- Indirect centerline cooling
- Cooling Section partitioning for preferential side (gas) heating
- Equalizing Section central partitioning allowing independent side firing
- Stable and precise temperature control
- ‘In-glass’ thermocouples

Indirect Centerline Cooling

When using colored glasses (such as Amber and Green) where color consistency is important, the Forehearth’s indirect centerline cooling helps maintain constant redox levels. Indirect cooling prevents cooling wind from mixing with combustion products. This provides a high degree of thermal efficiency for both heating and cooling systems. Changes in cooling wind do not affect forehearth internal pressure.

Individual cooling plates placed along the cooling section also allow cooling to be introduced more gradually. This reduces the likelihood of chilling the top glass.

Combustion System

The Forehearth combustion system is designed to work with either LPG or Natural Gas, and is based on, venturi mixers and pressure sensing ratio regulators to provide manifold pressures in the range of 20mm WC to 250mm WC.A combustion system based on flow sensing ratio regulators is available as an option.

Cooling Wind Control

The Forehearth uses individual blowers with variable speed drive controls. The slight increase in capital cost is more than offset by the significant operating energy cost savings.

Specifications:

Channel width :   460 mm - 1371mm
Tonnage range : 3 to 150 tons per day (depending on width)
Cooling mode :   Indirect centerline cooling
Control Configuration : Standard heat/cool PID control
Control sensors :            Thermocouples/Fibre Optic pyrometers depending
on glass color/customer preference
Combustion configuration : Pressure or flow sensing air/fuel ratio
control/customer preference
Glass Type : Suitable for all glass colors

A Better Forehearth

This advanced gas fired forehearth not only provides improved glass conditioning but, because of the increase in cooling capability, will accommodate wider tonnage and gob temperature ranges.

Typical Overview Display from the PLC based Advanced Forehearth Control System