高压断路器触头无线测温改造

介绍了无线测温系统的组成及无线测温传感器的技术性能,叙述了无线测温传感器在高压断路器上的安装方式和数据上传途径。无线测温装置安装后,设置报警温度60℃,>95℃时必须停电检查触头。无线测温系统运行后,发挥了提前预警、避免设备发生事故的作用。     

一起整流站开关柜事故的原因及处理措施

阐述了山东德州实华化工有限公司热电车间一起整流站开关柜事故发生的经过,分析了事故发生的原因,并提出了整改措施.     

盐酸尾气放空管着火的原因分析及预防措施

由于天气的缘故,鲁西化工集团热电股份公司盐酸工段尾气放空管顶端引起2次着火.就此问题,进行了原因分析并提出防范措施:消除静电火花;定期检查HCl合成炉炉嘴、尾气组分情况及整个吸收系统是否有漏气现象;尾气放空管着火时,用隔绝空气法扑救.     

Fire losses in selected property classifications of non‐residential,commercial and residential wood buildings. Part 1: hotels/motels and care homes for aged

In an attempt to evaluate the adequacy of building code requirements for selected classifications of non‐residential, commercial and residential wood buildings, researchers at Forintek Canada Corp. have examined Canadian and American fire loss statistics and compared fire losses for the selected classifications of wood buildings with those for similar buildings of non‐combustible construction. They have also examined causal factors associated with fires in those structures, extent of flame and smoke spread, ability of sprinkler systems and building construction to minimize fire losses, and outcomes of fire events. Because of the volume of information that was analysed, the results are being reported through three separate papers. This, the first, presents the ‘big picture’ with respect to fire losses in the selected classifications of non‐residential, commercial and residential structures, and discusses in detail fire losses for hotel/motel properties and care homes for the aged. Copyright © 2006 John Wiley & Sons, Ltd.     

Mechanisms and modes for ignition of low‐voltage,PVC‐insulated electrotechnical products

PVC is the most common insulation material used for wiring in low‐voltage (LV) service. ‘Low‐voltage’, in the context of this paper, is taken to be 120–240 VAC. The electrotechnical products considered include insulated wires, cables and cords, and also appurtenant termination devices, e.g. male plugs or female taps. Well‐known factors leading to the ignition of PVC‐insulated wiring and related products include: (a) manufacturing defects; (b) grossly excessive current; (c) over‐insulation, sometimes augmented by overcurrent; (d) localized heating due to strand breakage; (e) localized heating due to mechanical strand severing by staples or nails; and (f) localized heating due to failed terminations. Other failure modes are known but have received only limited study. These include (i) excessive force and creep; (ii) chemical interaction effects; and (iii) breakdown under voltage surge conditions. Additional research is needed in these areas. The proximate cause of ignition involved with many of the above mechanisms is arc tracking (arcing across a carbonized path). In turn, it is shown that PVC is especially susceptible to becoming charred, it requiring only approximately 160°C for the material to become semiconducting during short‐term exposure (around 10 h), while longer‐term exposure (around 1 month) may cause failures at temperatures as low as 110°C. Some limited data exist which suggest that standard UL and IEC temperature classifications are unduly optimistic, as applied to PVC. Fire can originate if wiring or equipment cannot withstand a powerline surge. Mains‐connected electrical appliances need to be designed to resist 6000 V surge voltages, even though this is not mandated in most of the current UL and IEC standards. Data are presented showing that the IEC 60112 wet‐tracking test gives especially misleading results for PVC and should be improved or abrogated. Copyright © 2005 John Wiley & Sons, Ltd.     

The mesh disturbance effects in a low‐temperature cascade arc torch for surface modification of low density polyethylene

A stainless steel mesh was placed in a low‐temperature cascade arc torch (LTCAT) to study its disturbance effects on the plasmas and on the surface modification of low density polyethylene (LDPE). It was found that the photoemitting species were deflected by the screen and only faint glow was observed after the mesh. Optical emission spectroscopy examination indicated that the amount of electronically excited species in the plasma was greatly reduced after passing through the mesh. Grounding the mesh altered the nature of the discharge and a greater intensity of O emission was observed in Ar LTCAT + O₂ discharge, which indicated greater energy transfer to the oxygen. Although a decrease in surface damage was observed on the treated LDPE samples by placement of the mesh in the Ar LTCAT discharges, the wettability achieved was also greatly reduced. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010