HORIZONTAL CONVEYOR FURNACES
Sargeant & Wilbur controlled atmosphere horizontal mesh belt conveyor furnaces are designed for economical and safe operation. The assembly consists of a loading area, purge chamber, furnace box, water-jacketed cooling chamber and unload area.
Sargeant & Wilbur conveyor furnaces are capable of annealing, sintering, glass to metal sealing of electronic packages and brazing metals with bright results. The purge chamber, furnace box and cooling chambers are sealed to one another to provide impermeable gas-tight protective atmosphere containment. The furnace can operate with a dissociated ammonia, exothermic gas, endothermic gas, hydrogen, nitrogen or blended gas protective atmosphere which provides a pure oxygen-free passage through the furnace assembly to prevent discoloration, (oxidation), of exposed metallic product surfaces at elevated temperatures. The conveyor belt travels through the furnace box within a heat resisting alloy muffle which is an impervious vessel which will receive and maintain the protective atmosphere. It will extend completely through the furnace and continue further in open air at both ends where it will be affixed and sealed to the purge chamber and cooler.
The electrically heated furnaces operating at temperatures of 2000°F and below will be supplied with 80 - 20 nickel-chromium heating elements and silicon carbide elements will be provided for furnaces operating at temperatures up to 2200°F.
Gas-fired furnaces are capable of operating at temperatures up to 2200°F
The furnaces are provided with a closed loop proportioning temperature control system capable of maintaining precise control of furnace temperature. The heating chambers may be divided into multiple independently controlled zones of thermal input to further advance repeatable control of furnace heating profile.
The alloy mesh conveyor belt will be pinch driven through a large diameter rubber lagged drum to assure long conveyor belt life. Conveyor belt speed will be regulated through a closed loop digital control system capable of moderating motor speed precisely with excellent reproducibility. The drive speed controller will receive a square wave input signal directly from a motor shaft sensor and will generate a corresponding output voltage across the conveyor drive motor. Open speed controllers, without feedback frequently experience control speed drift resulting in inconsistent product dwell within the heating chamber,. The corrective drive speed control capability represents a significant process variable regulating function to assure consistent uniform control of product quality.
Sargeant & Wilbur application engineers work directly with the customer to accurately determine the furnace which meets your requirements. The conveyor belt width, heating chamber length, cooling chamber length and drive speed range are determined by your process demands, product geometry, belt loading and required heating profile. We do not attempt to apply a standard design to your process specification. The proposed furnace will represent a unique response to your application. In the past 62 years we have manufactured over 1000 conveyor furnaces and there is no thermal process we have not encountered. We have shipped many different combinations of conveyor belt width and heating chamber length but very rarely produced two furnaces which were exactly alike.