39results about How to "Lower melt temperature" patented technology

The invention provides a method for directionally solidifying and purifying polycrystalline silicon by adopting ferro-silicon alloy and relates to a purifying method of polycrystalline silicon. The method comprises the following steps of putting industrial silicon powder into hydrochloric acid for soaking and then washing with deionized water; putting silicon powder and iron powder into a graphite crucible, putting the graphite crucible into a directional solidification furnace, closing a furnace cover, vacuum-pumping to below 10 Pa and introducing argon; opening an inductive heating power supply and carrying out heat preservation after the temperature in the graphite crucible reaches 1570-1650 DEG C; starting a directional solidifying lifting device for directional solidification and removing impurities in the silicon to obtain a cast ingot; putting the cast ingot into a vacuum annealing furnace for annealing treatment and then cooling the furnace to a room temperature to obtain an alloy cast ingot; and taking out the alloy cast ingot and cutting 20-40 percent of the upper part of the alloy cast ingot and obtaining a remainder, i.e. the polycrystalline silicon directionally solidified and purified by adopting the ferro-silicon alloy. The method has the advantages of low equipment cost, simple and feasible process, good purifying effect and very wide market prospect in the production field of the solar grade polycrystalline silicon.

The present invention relates to the technical field of directional solidification, in particular to a multi-mode excited deep subcooled directional solidification device and method, which includes a reaction furnace, a smelting device, a feeding device, an excitation device, a drawing rod and a drawing device, and the feeding device is used for Add purifying agent to the crucible during the heat melting process; the excitation device includes an excitation chamber that can be filled with liquid metal, a water-cooled ring layer and a liquid level controller that communicates with the excitation chamber, and the liquid level controller is used to control the liquid level of the liquid metal in the excitation chamber ; The pulling device can pull at least a part of the crucible into the excitation chamber at a predetermined speed range through the pulling rod. This device realizes the deep subcooling of the melt through the combination of glass purification and cyclic superheating, and ingeniously combines smelting, liquid metal / water dual cooling and drawing devices. Different modes can be selected to stimulate the directional solidification of the deep supercooled melt, so that it can Obtain deep supercooled directional solidification castings with different microstructure and performance characteristics to meet more research and application needs.

The invention discloses PP-R (polypropylene) pipe production equipment. The PP-R (polypropylene) pipe production equipment comprises an extruder, a machine head arranged on the extruder, and a forming head arranged at an outlet end of the machine head, wherein the machine head comprises a core model, a mouth model, an adjusting seat, a core model afterbody, an outer model afterbody, and a core model seat; the core model afterbody comprises a flange and a core model section, the core model section of the core model afterbody is conical and is inserted into an inner hole of the outer model afterbody, the core model afterbody is internally provided with a feeding inlet, a spiral chute is arranged in the outer surface of the core model section of the core model afterbody, the depth of the spiral chute is gradually shallower from the head part to the tail part, and the head part of the spiral chute is communicated with the feeding inlet by a distribution hole arranged in the core model afterbody. When materials pass through the spiral chute, the melt flow is changed from the axial direction to the radial direction, thereby playing a good mixing effect and effectively eliminating the stress memory property of a melt.