Furnace equipments products

Stirrer Mechanism

The purpose of the Stirring Mechanisms is to homogenize the glass in the forehearth. The main applications are:

Taking into account the severe working conditions due to the high working temperatures, special attention has been paid to select the appropriate materials, both for the steel supporting frame and for the moving parts which are subject to wear, in order to improve their reliability and to reduce as much as possible the maintenance operations.



Generally a stirrer mechanism comprises the following:

Glass Service produces the following stirrer systems:

Flag-Type Stirrer Mechanism

The stirring machine consist of:

Technical Characteristics

Vertical height
Approx. 2.275 mm - customizable
Vertical stroke of stirring mechanism
Approx. 950 mm - customizable
Distance from center forehearth to support column
N° of rotors
1 to 5
Max. weight stirrers
120 kg each
Stirrer revolution speed (manual adjustment) - screw type
4.8 – 26 rpm
Stirrer revolution speed (manual adjustment) - paddle type
1.3 – 12,6 rpm

Installed Power

0.75 kW
Power supply
380 V 3 Ph – 50 Hz / 440V 60 Hz

Maintenance and Replacement of Stirrers

The maintenance and the replacement of the paddles/screws is easily carried out. The operation sequence for this is as follows:

X-Y Stirrer Mechanism

Minimal installation spaces

Maintenance operation simplified

Quick type coupling system for refractory screws or paddles

Bearing cooled
and lubricated

Up to 5 rotors installable

Minimum space required for stirrer replacement


Glass Service has developed a stirring mechanism with two movements on both the X and Y axes that greatly reduces the space required for the installation and simplifies any maintenance operation. This machine is a vertical structure attached to the forehearth steel frame. An electric motor drives the chuck support arm up and down the structure.

This Y movement is achieved by moving the supporting arm on two parallel reinforced rails with special bearings and reinforced wheels. The motor and gearbox are located on top of the structure with a chain directly coupled to the chuck holder arm. In the unlikely event of chain breakage the arm cannot fall down due to the special design of the rails. The chuck support arm can easily slide towards the side of the forehearth on a horizontal arm. This movement is again operated on two parallel and reinforced rails with special bearings and reinforced wheels whilst power transmission is achieved through a rack and pinion. Each spindle turns on large graphite ball bearings. Thanks to this innovation the following features can be achieved:

  • Minimum installation space
  • Any maintenance operation, both on paddles or motor, is simpler and performed away from the hottest area of the forehearth
  • The re-positioning of the spindles over the forehearth is very simple and precise.

Technical Characteristics

General dimensions
According forehearth dimensions
N° of rotors
1 to 5
Rotors interaxis
Max. weight of each stirrer
60 kg
Stirrer revolution speed (manual adjustment) - screw type
4.8 – 26 rpm
Stirrer revolution speed (manual adjustment) - paddle type
1.3 – 12.6 rpm
Installed power
0.75 kW
Installed power for spindle arm raising mechanism
0.18 kW
Power Supply


On the top of the chuck holder arm the rotors power transmission group is located. Rotors are driven by a motor plus its gearbox, allowing a perfect control of the rotation speed.
This group is designed to allow, for each rotor, the possibility to rotate in two directions, so that, according to the installation the system can be configured as following:

  • All rotors with the same rotation sense
  • Each rotor rotating in opposite rotation

Optionally an inverter can be used to control the rotation speed. Each moving part of the machine is fitted with steel guards for safety purposes as well as to protect the mechanisms from dust. The drive assembly is also cooled and lubricated by means of compressed air.
The machine can support any type of rotor currently available on the market.
The chuck and rotor coupling system is a quick release model.

Maintenance and Replacement of Stirrers

The maintenance and replacement of the paddles/screws is easily carried out and requires very little space at the side of the forehearth. The operation sequence for this is as follows:

Rotors Type

Rotors type selection

Two types of rotors can be used, these are:

Glass Service will suggest the correct type of rotor according to the customer requirements.

Below are some types of rotors that Glass Service can supply according to the requirements of the customer (and many others…):

Rotors positioning

Depending on the forehearth width, type of glass, type of colouring, the available space at the sides of the forehearth etc., we will offer the best solution for the installation of the stirring unit.

Below are simple sketches of a possible installation:

Control cabinet

Glass Service can provide a compact control cabinet including:

As an option we can provide remote control cabinet with:


There are some options that we can provide: