應用本質較安全策略探討機械安全連鎖裝置較佳化設計之研究–以某TFT-LCD廠為例

Abstract

LCD生產設備具有大型化、高速化、自動化等特性，且設備尺寸仍不斷放大，複雜的生產設備間存在著各種可能造成嚴重傷害的危害源。從TFT-LCD產業重大傷亡及分析某光電廠之職災傷害類型，仍以機械傷害為首。分析事故原因，以機械設備的本質安全性及安全連鎖裝置失效等安全防護不足為主因，其次為人員作業錯誤所造成。 事實上機械不可能不故障，且又無法保證人員永不錯誤。針對機械的危害，本研究將應用本質較安全策略，其作法有強化、取代、減弱、限制影響、簡單化、避免骨牌效應、防愚設計、狀態清晰、容忍、易於控制及軟體等，利用其優勢並搭配結合安全連鎖裝置較佳化設計，以電磁式、舌片式、動力源多樣化及安全光柵等型式之應用，達到使人員要進入能量運作空間危險區域時，能量的運作必須停止;而當能量要開始運作時，可確保人員不在危險區域。並藉由案例來驗證其防護安全性，對於操作人員的安全，全面進行新人及在職人員機台操作安全及危害認知等訓練及查核獎懲制度之執行，讓員工了解機台的危害及針對不同作業危害訂定其安全標準作業規範，使作業人員能確實依標準作業程序作業。達到防止發生重大職業災害致生產中斷之不可接受風險之研究目的。

LCD production equipments are featured by large scale, high speed, and automation. As larger and more complex equipments continue to become available, there are various hazard sources that may cause serious damages. Analysis on serious casualties occurred in the TFT-LCD industry and the occupational injury types of a photoelectric plant indicated that, mechanical injury is the primary cause. The main reason is insufficient safety protections, such as failure of intrinsic safety on the mechanical equipment and safety interlock, followed by improper operation. However, it is inevitable for machines to encounter malfunctioning and for personnel to make mistakes. Hence, this study applied intrinsically safe strengthening, substitution, attenuation, limitation of effects, simplification, avoidance of domino effect, foolproof design, clear status, tolerance, easy to control, and software. These strategies were combined with the optimum design of safety interlock, in the forms of electromagnetic type, tongue type, diversification of power sources, and safe optical grating. There fore, once personnel enter into the danger zone of energy operation space, the energy operation will stop, and the personnel are guaranteed to be out of the danger zone once the energy operation restarts. Meanwhile, a case study was conducted to verify the protection safety. To ensure the operators’ safety, comprehensive trainings could be provided for newly-hired and in-service staffs on the operating safety and hazard recognition of the equipments. Moreover, a reward and penalty system could be implemented to reinforce the staffs’ understanding of the machinery hazards and the safety standards. The code for practice against different operating hazards needs to be established to ensure the operators to operate in accordance with the standard procedures in order to prevent the unacceptable risk of production interruption caused by occupational hazards.