Gradmatic Refractory Installation and Vibration System
The Refractory Installation and Vibration System has four components to install completely and vibrate any dry refractory, not just silica. Each component can be purchased individually or all units as a system. No other company offers a more comprehensive system to install and vibrate dry refractory in coreless induction furnaces.
Furnace Floor Vibrator
Installation and Vibration of Furnace Floor Material
Material is added to the furnace bottom by hoist using bulkgags which are available from most refractory suppliers, with specially designed spouts to reduce airborne dust.
The furnace bottom is compacted in one operation, from the furnace deck, using a vibrator plate equipped with two electric vibrators. The vibrator plate, custom designed to fit the floor diameter ensuring even and full vibration, is lowered by hoist. Floor vibration is accomplished in about 12 minutes (depending on furnace size) with no worker entering the confined space of the furnace and risking exposure to hazardous dust.
Conventional vibration requires workers to enter the furnace and can take more than one hour, depending on the size of the furnace.
Refractory Vibration System
Vibrating furnace sidewalls using the Refractory Vibration System
The sidewalls are vibrated using a three-legged machine, each leg being equipped with an electric vibrator. A central cylinder extends the spring-loaded legs against the interior of the form, simultaneously delivering equal force to the three contact points. Furnaces 15 metric ton capacity and larger are vibrated using a four-legged vibrator.
The unit is lowered to the bottom of the furnace with vibration beginning one inch (25 mm) above the base of the form. The legs are adjusted against the angle of the taper using an air valve to ensure that contact is controlled and consistent during vibration. Vibration is concentrated in the tapered section of the form where maximum compaction is critical to long lining life. Eight of the typically fourteen minutes total vibration time is spent in this area. The machine is then slowly pulled up the form, ensuring equal treatment for the entire length of the parallel section.
Conventional vibration is either by direct vibration of the refractory or by vibrating the form. Both methods are labour intensive, time consuming and do not adequately vibrate the tapered section where premature wear and “elephant foot” erosion commonly occurs.