• Journal of the Korean Society of Safety
• /
• v.34 no.5
• /
• pp.37-45
• /
• 2019

The characteristic of fire and explosion related to electrostatic discharge is that it is difficult to reproduce the electrostatic charge and discharge phenomenon in addition to the large human and material damage. Therefore, in order to prevent accidents and disasters related to electrostatic in fire and explosion hazard areas, it is important to manage the level of electrostatic in a safe manner from the perspective of system between industrial facilities and human bodies. Rule 325 of the Occupational Safety and Health Regulations, "Prevention of Fire / Explosion due to Electrostatic", requires the use of grounding, conductive materials, humidification and electrification in order to prevent the risk of disaster caused by static explosion and electrostatic in the production process. In order to comply with these measures, related technologies, standards and systems are needed from the viewpoint of preventive measures related to electrostatic in fire and explosion hazard areas, but in Korea, it is still insufficient. Therefore, technical, institutional and managerial measures are needed as a precautionary measure to improve the level of ESD safety in fire and explosion hazard areas and prevent electrostatic related injury. In Korea, we analyzed the current status and characteristics of electrostatic related disaster by using the statistics of industrial accident and fire statistics of the Ministry of Employment and Labor. We also analyzed the current status and characteristics of electrostatic related disasters in Japan using JNIOSH accidents and disasters investigation cases and JNIOSH fire accident data of Japan Fire Bureau. The purpose of this study is to compare and analyze the current status of electrostatic related accidents and disasters in Korea and Japan in order to improve the safety management of electrostatic in fire and explosion hazard areas. In order to prevent accidents and disasters in the industrial field, The technical, institutional, and managerial measures to manage the level of electrostatic in a safe state were derived from the system point of view.

• Journal of the Korean Institute of Gas
• /
• v.4 no.2 s.10
• /
• pp.33-36
• /
• 2000

As a result of electrostatic hazard analysis of electrostatic removing wear about combustible gas, in accordance with using period, character of charge voltage is shown that propensity is increased. but character of electrostatic charge amount is below standard(0.6 $\mu$C) of the hazard of electrostatic removing wear, It would seem that character of charge voltage is raised because of swelling phenomenon of the normal fiber and other phenomena. Besides, In some case '96 parka of electrostatic removing wear shown as 0.82$\mu$C that exceed the uppermost limit of the fire and explosion. Therefore, countermeasure or improvement and control are needed.

• Korean Chemical Engineering Research
• /
• v.59 no.3
• /
• pp.359-365
• /
• 2021

We investigated experimentally the ignition characteristic of dust and the hazard evaluating for electrostatic discharge. The ignition energy experiments were performed on sample dusts such as PE(HD), PE(LD), PMMA using the MIKE-3 apparatus. The formation of flame during the ignition of PE(HD) dust clouds occurred after the delay time of about 8 ms, and the flame kernels were not observed in center of ignition occurrence area. The voltage increased with increasing the number of dust dispersions and the increase rate of measured voltage with dust concentration was the highest in the order of PMMA, PE(LD) and PE(HD). For the effect of dispersion condition on the voltage in PE(HD) dust, the results were obtained that the voltage increased as the number of dispersions increased and as the concentration increased under the same dispersion number. The safety voltages to prevent fire and explosions by electrostatic ignition were estimated that PE(HD), PE(LD)-1, PE(LD)-2, and PMMA were 2.58, 44.72, 25.82, and 8.16 kV, respectively. We proposed the method for estimating the minimum ignition energy by using the measured voltage data for efficient investigation of electrostatic ignition hazard.

• Journal of the Korean Society of Safety
• /
• v.24 no.6
• /
• pp.39-44
• /
• 2009

In order to prevent fire and explosion due to the electrostatic discharge at the Gas Station etc. This result will be applied to standard in the future. Wearing the non-electrostatic removing wear, Charged voltage of human body is 3,980V(MIE is approximately 0.79mJ). There is a possibility of fire explosion because the MIE of LP gas is 0.25mJ. In accordance with using period(whasing times), Charged voltage is shown that propensity is increased. Electrostatic charge amount is upper standard($0.6{\mu}$C) of the hazard of electrostatic removing wear. There is a possibility of fire and explosion. Therefore, countermeasure and management are needed about gas station worker.

• Journal of the Korean Society of Safety
• /
• v.25 no.4
• /
• pp.19-24
• /
• 2010

A large amount of electrostatic charges is often generated on polymer powders in fluidized bed and thereby may lead to electrostatic problems. In this study, to evaluate electrostatic hazards of powder in fluidized bed, the electric field(E[v/m]) and the charge amount(q[c/g]) during fluidizing were monitored. We also investigated the Minimum Ignition Energy(MIE [J]) of sample powder used in fluidized bed with the Hartman vertical-tube apparatus. The batch-type fluidized bed system and 2kg as Polypropylene(PP) resin powders were used in the experiments. The following results were obtained: (1) Even when a safe margin of several times was considered, the values of E obtained with PP powder in this paper did not exceed 3 to 5kV/cm, at which an incendiary electrostatic discharge could occur. (2) the ave. q was -0.26${\mu}$C/g during fluidizing. This value was high enough to cause electrostatic agglomeration and adhesion. (3) the entrained PP powder in upper column due to fluidizing could be ignited by electrostatic discharges of 71mJ.

• Journal of the Korean Society of Safety
• /
• v.26 no.3
• /
• pp.15-22
• /
• 2011

Explosion and fire cause about 30 reported industrial major accidents a year by ignition source which discharge of electrostatic generated to flammable gas, vapor, dust and mixtures. It brings economically and humanly very large loss that accident was caused by fire and explosion from electrostatic discharge. Thus, it is very important that electrostatic discharge energy is to be control below not to be igniting flammable mixtures. There are two kinds of analysis model for electrostatic discharge, human body model and machine model. Human body model is available the parameter of human's electrical equivalent that capacitance is 100 pF, resistance is $1.5k{\Omega}$. To simulate and visualize the electrostatic discharge from human body need a very expensive and high voltage simulator. In this paper, we measured the value of capacitance and resistance concerned with test materials and sizing of specimen and the value of charged voltage concerned with test specimen and distance to develop an electrostatic charge/discharge simulating tool for teaching with which concerned industrial employee and students. The result of experiments, we conformed that the minimum ignition energy of methane-oxygen mixtures meets well the equation $W=1/2CV^2$, and found out that the insulating material and sizing of equivalent value having human body mode are the poly ethylene of 200 mm and 300 mm of diameter. Developed electrostatic charge/discharge simulating tool has many merits; simple mechanism, low cost, no need of electric power and so on.

• Journal of the Korean Society of Safety
• /
• v.35 no.1
• /
• pp.1-11
• /
• 2020

Article 325 (Prevention of Fire Explosion due to Electrostatic) of the Rule for Occupational Safety and Health Standard specifies that in order to prevent the risk of disasters caused by static electricity, fire, explosion and static electricity in the production process, However, in order to do this, it is absolutely necessary to use a pre-detection technology and a detector for antistatic discharge prediction, which is a precautionary measure by static electricity in a fire / explosion hazard place, but in Korea, And there is no technical standard for the application of the technology of the explosion proof structure of the related equipment. Research methods include domestic and overseas electrostatic discharge detection technology and literature investigation of related equipment explosion proofing technology, domestic and foreign electrostatic discharge detection device production and use situation investigation, advanced foreign technology data analysis and benchmarking. In particular, we sought to verify the results of empirical experiments using electrostatic discharge detection technology through sample purchase and analysis of related major products, development of optimization technology through prototype production, evaluation, and supplementation, and expert knowledge through expert consultation. The results of this study were developed and fabricated two prototypes of electrostatic discharge detector based on the technology / standard related to electrostatic discharge detection technology in Korea and abroad through development of electrostatic discharge detection technology and development and production of detector. In addition, based on the development of electrostatic discharge detection technology, we developed an intrinsic safety explosion proof ib class explosion proof technology applicable to the process of using and handling flammable gas and flammable liquid vapor and combustible dust. In the case of the over voltage and minimum voltage are supplied to the explosion-proof structure ESD detector, check the state of the circuit and the transient and transient currents generated by the coil and capacitor elements during the input and standby of the signal pulse voltage. Explosion-proof equipment-Part 11: Intrinsically safe explosion proof structure The comparative evaluation with the reference curve in Annex A of "i" confirms that the characteristics of the intrinsically safe explosion protection structure are met.

• Journal of the Korean Society of Safety
• /
• v.25 no.4
• /
• pp.13-18
• /
• 2010

To investigate electrostatic ignition hazards of commercial gasoline used in the gas station, experiments were conducted dealing with the minimum ignition energy(MIE) of several kinds of gasoline under the various temperature. The conductivity of gasoline that was required for an accurate risk assessment as well as the MIE were also examined. The solvent ignitability apparatus which can heat up the inside of the vessels up to $210^{\circ}C$ was used in this study. Four kinds of premium gasoline and four kinds of regular gasoline, differing with respect to the companies, were used as test specimens. The following results were obtained: (1) all gasoline specimens were so sensitive that even an electrostatic discharge with a very low energy, such as about 0.5mJ, could ignite them. The ignitability of premium gasoline was constant irrespective of the companies. On the other hand, the ignitability of regular gasoline was variable depending on the company. (2) The MIE of all specimens depended markedly on the temperature; in other words, an increase in temperature decreases the ignition energy value. (3) The conductivity values of all specimens were low. Those must be taken into consideration in electrostatic risk assessment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.10a
• /
• pp.53-54
• /
• 2017

In this paper, we have studied the electrostatic discharge test for the battery protection circuit module in the lithium ion battery used as a smartphone battery which is used to prevent the explosion hazard due to overcharge, over discharge, and short-circuit. A lithium ion battery of S company was used as an experimental sample, and an ESD gun simulator compliant with IEC 61000-4-2 standard was used for electrostatic discharge injection. The contact discharge was applied to the various pins of the battery protection circuit module in increments of 2 kV in the range of 2 kV to 10 kV and in 5 kV increments in the range of 10 kV to 30 kV.

• Journal of the Korean Society of Safety
• /
• v.34 no.4
• /
• pp.22-31
• /
• 2019

The flammable liquid conductivity is an important factor in determining the generation of electrostatic in fire and explosion hazardous areas, so it is necessary to study the physical properties of flammable liquids. In particular, the relevant liquid conductivity in the process of handling flammable liquids in relation to the risk assessment and risk control in fire and explosion hazard areas, such as chemical plants, is classified as a main evaluation item according to the IEC standard, and it is necessary to have flammable liquid conductivity measuring devices and related data are required depending on the handling conditions of the material, such as temperature and mixing ratio for preventing the fire and explosion related to electrostatic. In addition, IEC 60079-32-2 [Explosive Atmospheres-Part 32-2 (Electrostatic hazards-Tests)] refers to the measuring device standard and the conductivity of a single substance. It was concluded that there is no measurement data according to the handling conditions such as mixing ratio of flammable liquid and temperature together with the use and measurement examples. We have developed the measurement reliability by improving the structure, material and measurement method of measuring device by referring to the IEC standard. We have developed a measurement device that is developed and manufactured by itself. The test results of flammable liquid conductivity measurement and the data of the NFPA 77 (Recommended Practice on Static Electricity) Annex B Table B.2 Static Electric Characteristic of Liquids were compared and verified by conducting the conductivity measurement of the flammable liquid handled in the fire and explosion hazardous place by using Measuring / Data Acquisition / Processing / PC Communication. It will contribute to the prevention of static electricity related disaster by taking preliminary measures for fire and explosion prevention by providing technical guidance for static electricity risk assessment and risk control through flammable liquid conductivity measurement experiment. In addition, based on the experimental results, it is possible to create a big data base by constructing electrostatic physical characteristic data of flammable liquids by process and material. Also, it is analyzed that it will contribute to the foundation composition for adding the specific information of conductivity of flammable liquid to the physical and chemical characteristics of MSDS.