论文部分内容阅读
钨、钼材料的电阻温度系数较大,因而钨、钼丝炉在升温和工作过程中,由于炉温的变化,特别是冷炉起动时,极易产生过大的电流。在目前的可控硅装置中,常加装快熔或晶体管过流保护线路。 本文介绍一种更佳的过流保护方案——电流截止保护。它能获得下垂的伏安特性,可将钨、钼丝炉由于炉温变化引起的非故障性过流,抑制在可控硅允许的工作电流范围内。这样,不仅可保证炉子的连续正常运行,实现钨、钼丝炉的自动升温和控温,还可减小设备容量、节省投资。 本线路已成功地使用在我院研制的模拟热处理炉和真空钎焊炉上,具有简单、经济、实用的特点。
The temperature coefficient of resistance of the tungsten and molybdenum materials is relatively large, so the tungsten and molybdenum wire furnaces can easily generate excessive current due to the change of the furnace temperature, especially when starting the cold furnace, during the heating and working process. In the current SCR devices, often with fast-melting or transistor over-current protection circuit. This article describes a better overcurrent protection scheme - current cut-off protection. It can achieve drooping volt-ampere characteristics, and can cause non-fault overcurrent in tungsten and molybdenum furnace furnaces due to the change of furnace temperature, and can be suppressed within the allowable working current range of thyristors. In this way, not only can the continuous normal operation of the furnace be ensured, but also the automatic temperature rise and temperature control of the tungsten and molybdenum wire furnaces can be reduced, the equipment capacity can be reduced, and the investment can be saved. This line has been successfully used in our research and development of simulated heat treatment furnace and vacuum brazing furnace, with simple, economical and practical features.