STOPPER ROD SYSTEM

(Modernization of existing casting plants)

The device described here is the Progelta Stopper Rod System. It is designed to start, stop and control the flow of iron being poured. The operation is designed to be completely automatic. The stopper rod holder is made of stainless steel, a material suitable to withstand liquid iron.

The Stopper Rod Drive Assembly comprises a motor that causes the vertical movement on a ball screw.
The electric motor is of the brushless type. This type of motor permits a dynamic response and gives control over the position of the stopper with promptness and precision to about 0,1mm.

The Stopper Rod Drive Assembly can be rotated on its support axis (except in cases where there are constraints caused by connection cables), simply by lifting the rod to the upper stroke limit so that the rotation guide bar is raised above the upper brass (1), making the rotation possible (2).

.

This makes access for cleaning and replacing the bar easy.

All moving parts and the stopper rod guide are protected by a cylindrical casing; one part to protect the motor compartment, and the other part to protect the sliding guide.

This casing can be easily opened and removed for normal maintenance operations.

The motor is connected to the control unit with two cables and connectors. One connection is to the power supply, and the other is to the encoding transducer that measures the opening of the stopper.

In addition, a device is installed inside the housing that detects the temperature at the motor and if necessary will activate the cooling system. The temperature is monitored at the supervision computer and an alarm is generated should the temperature exceed a given level.

The cooling system is via two Vortex coolers (air conditioning devices working with compressed air). Fan coolers can be installed on request and depending on operating conditions.

Technical Specifications

Overall weight of the Stopper Rod System 213 kg
Weight of the stopper holder 15 kg
Maximum mechanical stroke 490 mm
Maximum working stroke 100 mm
Power Supply 380/480 Vac
Command signal modulated voltage
Air pressure (for Twist Cylinder) 6 bar Max.
Max. Temperature of the installation environment 60 ° C

The Progelta Stopper Rod System can be fitted with additional devices, such as the Nozzle Cleaning Assembly to clean the nozzle of the stopper rod, and the Progelta Twist to improve sealing the stopper rod in the closure to prevent the iron from leaking.

Progelta Nozzle Cleaning System

The Nozzle Cleaning System consists of a specially manufactured cylinder that plunges a steel bar through the nozzle hole to remove the slag build-up that causes narrowing of the diameter and consequently slows the liquid metal flow rate.

The cleaning bar (or pipe) is a consumable part. For this reason the cleaning device is equipped with a coupling unit to enable quick replacement of the cleaning bars.

The cleaning cylinder is installed on board of the stopper device and moves the cleaning bar up and down inside the stopper. The arrangement allows the installation of the correct length of cleaning bar.

The cleaning cycle can be manually operated by a push button on the command console or it can be automatically induced by PLC control according to set intervals.

Maintenance Operators of the customer can do the installation. There is no need for intervention by Progelta technicians. All details regarding mechanical, pneumatic and electric installations will be supplied with the device.

The Progelta Nozzle Cleaning System is designed to work on Progelta Stopper Rods. We can, if required, work on the possibility of adapting our design to work on Stopper Rods of other makes.

Progelta Twist

Progelta has developed a system to rotate the stopper in order to refresh the contact surface between the closed stopper and the seat, stopping iron from leaking. This system, called “Twist”, consists of a pneumatic cylinder, which by means of a special mechanism causes the partial rotation of the stopper.
This is useful in the case where dirt (slag) intrudes between the stopper and bushing, causing leakage.

The installation of the Twist to the Progelta stopper drive system is easily done with an accessory kit. We can investigate the possibility of such installation on other types of stopper drives.

The operation of the twist causes no delay in cycle of the casting system.