TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The upper cover is provided with an explosion-proof top cover, which is formed by welding the double layers of stainless steel plate and a flange. An observation window opens in the middle of the explosion-proof cover with a thermocouple hole and a charging hole. The middle barrel body is provided with a vacuum pipeline, a coil heating electrode joint, a middle barrel body supporting seat, a furnace cover lifting seat, a locking buckle and furnace supporting legs. The inner part of the middle barrel body is set with a stainless steel frame. The upper part of the stainless steel frame is provided with a copper heating coil. The copper heating coil is provided with a temperature resistant heat insulating material and graphite magnetic conducting heating body. The lower part of the stainless steel frame is provided with a heat preservation barrel body. The lower furnace cover is provided with a lower furnace body lifting seat, a lifting screw rod and a lower cover locking buckle handle. The lower part of the furnace cover is equipped with a crucible lifting mechanism and a door lifting mechanism. The crucible lifting mechanism and door lifting mechanism are composed of a heating lifting platform and a crucible lifting platform. The lifting platform comprises a heating door fixing support and a fixing plate. The lifting platform ensures vertical operation of four straight line guide rails through a lifting speed reducer. The lifting speed reducer through a servo motor drives the screw driven rotary crucible lifting platform and the door lifting platform to perform lifting operation. The door lifting platform is connected with the crucible lifting platform through a straight line shaft. The lower furnace cover is set with a crucible, a graphite crucible cover, a crucible graphite plate, a graphite heat exchange platform and graphite felt heat preservation cover (21). The crucible graphite plate, graphite heat exchange platform, graphite crucible cover and crucible ensures up and down movement along with the graphite heat exchange platform through the crucible lifting mechanism. The graphite felt heat preservation cover moves up and down through a lifting mechanism, and controls the crystal growth by controlling the speed to form temperature gradient for silicon material in the crucible. The lower part of the graphite felt heat preservation cover is set with a silicon melting anti-leakage alarming device and silicon leakage anti-leakage groove. The silicon melting anti-leakage alarming device is divided into a silicon liquid leakage fuse alarm and leak alarm. The silicon leakage fuse alarm is formed by a stainless steel support and a copper-wire porcelain element. The copper wire is uniformly wound around the porcelain element. The copper-wire porcelain element is uniformly distributed in a graphite anti-leakage material receiving groove connected to the silicon melting anti-leakage alarming device. The silicon leakage fuse alarm is installed on the lower part of the silicon melting anti-leakage alarming device, and comprises the double layers of stainless steel, and a dense steel wire net. The middle of the wire mesh is composed of insulating porcelain pieces to separate the double layers into two electrodes. The lower part of the graphite anti-leakage material receiving groove is paved with flame-resistant alumina felt and silicon dioxide ore. The center of the upper furnace cover is provided with an anti-explosion opening with a diameter of 800 mm, and the upper end of the vacuum pipeline is provided with an explosion-proof opening with a diameter of 600 mm.