Applications of dust explosion hazard and disaster prevention technology

Highlights

• The imperfect of PSI is the main reason for the continuous occurrence of dust accidents.

• Dust hazard characteristic parameters are important PSI for the implementation of PHA.

• Create a safety management framework and standard for flammable dust workplaces.

• The most non-compliant factor found in dusty locations is explosion-proof electrical equipment wrong choice.

• Lack of verified dust hazard characteristics parameters lead to underestimation of process risk.

Abstract

Powdered materials are widely used in industrial processes, chemical processing, and nanoscience. Because most flammable powders and chemicals are not pure substances, their flammability and self-heating characteristics cannot be accurately identified using safety data sheets. Therefore, site staff can easily underestimate the risks they pose. Flammable dust accidents are frequent and force industrial process managers to pay attention to the characteristics of flammable powders and create inherently safer designs.

This study verified that although the flammable powders used by petrochemical plants have been tested, some powders have different minimum ignition energies (MIEs) before and after drying, whereas some of the powders are released of flammable gases. These hazard characteristics are usually neglected, leading to the neglect of preventive parameters for fires and explosions, such as dust particle size specified by NFPA-654, MIE, the minimum ignition temperature of the dust cloud, the minimum ignition temperature of the dust layer, and limiting oxygen concentration. Unless these parameters are fully integrated into process hazard analysis and process safety management, the risks cannot be fully identified, and the reliability of process hazard analysis cannot be improved to facilitate the development of appropriate countermeasures. Preventing the underestimation of process risk severity due to the fire and explosion parameters of unknown flammable dusts and overestimation of existing safety measures is crucial for effective accident prevention.

Introduction

On June 27, 2015, a major flash-fire accident involving corn flour occurred (Color Play Asia). Multicolored corn flour was sprayed into the air during an event at Formosa Fun Coast in New Taipei City, Taiwan; the powder ignited, and the accidental flash fire resulted in 15 deaths and 484 injuries, increasing the public's awareness of fire accidents (Chen and Shu, 2015; Wang et al., 2017; Yang and Shih, 2016). In addition, according to investigations, the petrochemical plants (located in the central and southern regions of Taiwan) of two different companies had acrylonitrile–butadiene–styrene (ABS) dust fire and explosion accidents, respectively, on July 10, 2015, and March 21, 2017 (Wu et al., 2019). Most fire and explosion accidents involving flammable dust occur at petrochemical or processing plants in which flammable dust is used as raw material in production or the finished product is flammable dust (Chen et al., 2012; Jones, 2003). To help prevent losses in factories, this study summarized 26 combustible dust fire and explosion accidents that occurred in petrochemical or processing plants in Taiwan and mainland China from 2005 to 2017 (Table 1). The statistics show that flammable dust fire and explosion accidents in Taiwan's petrochemical and processing plants occur approximately once every two years. This was repetitive. Please review.

In an investigation of the causes of the aforementioned dust fire and explosion accidents, the safety data sheets (SDSs) of the chemical powders did not contain the six fire and explosion prevention parameters for chemical powders, namely powder particle size and moisture content, minimum ignition energy (MIE), the minimum ignition temperature of the dust layer (MITL), the minimum ignition temperature of the dust cloud (MITC), and the limiting oxygen concentration (LOC). Therefore, numerous fire and explosion accidents involving flammable dust during factory operation have occurred. Dust explosion accidents in petrochemical plants and the colored corn flour flash fire at Formosa Fun Coast were caused by insufficient process safety information (PSI) regarding dust, leading to underestimation of process risks and overestimation of existing safety and protection measures (Barton and Rogers, 1997; Knegtering and Pasman, 2009).

To explore the proportion of petrochemical plant fire and explosion accidents in which the severity of process risks was underestimated and existing safety and protection measures were overestimated due to insufficient PSI, this study collected the accident reports of 46 fires that occurred in petrochemical plants or general factories in Taiwan from 2012 to 2019. Quantitative analysis was performed on 88 items related to the accidents’ causes and process safety management (PSM) (Amyotte and Lupien, 2017; Swuste et al., 2016). The summarization results revealed that PSI was insufficient in 25 of the accidents. The most critical management item of PSM is thus PSI, as illustrated in Fig. 1.

This study cooperated with a Taiwanese petrochemical group that promotes fire and explosion prevention and is conducting a project for controlling workplaces in which flammable dust is present. In total, a project inventory of 102 such workplaces in 77 of the group's Taiwanese plants was performed. During the project's launch, this study focused on 19 dust operation sites in 11 petrochemical plants. A total of 17 samples of combustible dust (including that produced and that used in production) from the sites were used to conduct experiments and identify 82 missing fire and explosion prevention parameters. The unknown fire and characteristic explosion parameters of the flammable dusts were investigated after the experiment to analyze the level of the flammable dust fire and explosion hazard, complementing safety inspections at work sites. The parameters were used to review whether worksite safety and protection measures have been established correctly and thus identify any inadequacies related to plant safety and provide suggestions for improvement.