• Korean Chemical Engineering Research
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• v.57 no.5
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• pp.637-651
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• 2019

In the event of a major accident such as an explosion in a refinery or a petrochemical plant, it has caused a serious loss of life and property and has had a great impact on the insurance market. In the case of catastrophic incidents occurring in process industries such as refinery and petrochemical plants, only the proximate causes of loss have been drawn and studied from inspectors or claims adjustors responsible for claims of property insurers, incident cause investigators, and national forensic service workers. However, it has not been done well for conducting root cause analysis (RCA) and identifying the factors that contributed to the failure and establishing preventive measures before leading to chemical plant's catastrophic incidents. In this study, the criteria of warning signs on CCPS catastrophic incident waning sign self-assessment tool which was derived through the RCA method and the contribution factor analysis method using the swiss cheese model principle has been reviewed first. Secondly, in order to determine the major incident warning signs in an actual chemical plant, 614 recommendations which have been issued during last the 17 years by loss control engineers of global reinsurers were analyzed. Finally, in order to facilitate the assessment index for catastrophic incident warning signs, the criteria for the catastrophic incident warning sign index at chemical plants were grouped by type and classified into upper category and lower category. Then, a catastrophic incident warning sign index for a chemical plant was developed using the weighted values of each category derived by applying the analytic hierarchy process (pairwise comparison method) through a questionnaire answered by relevant experts of the chemical plant. It is expected that the final 'assessment index for catastrophic incident warning signs' can be utilized by the refinery and petrochemical plant's internal as well as external auditors to assess vulnerability levels related to incident warning signs, and identify the elements of incident warning signs that need to be tracked and managed to prevent the occurrence of serious incidents in the future.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.252-259
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• 1997

A method to automate hazard analysis of chemical plants is proposed in this paper. The proposed system is composed of three knowledge bases - unit knowledge base, organizational knowledge base and material knowledge base, and three hazard analysis algorithms - deviation, malfunction and accident analysis algorithm. Hazard analysis inference procedure is developed based on the actual hazard analysis procedures and accident development sequence. The proposed algorithm can perform hazard analysis in two methods and represent all conceivable types of accidents using accident analysis algorithm. In addition, it provides intermediate steps in the accident propagation, and enables the analysis result to give a useful information to hazard assessment. The proposed method is successfully demonstrated by being applied to diammonium phosphate manufacturing process. A system to automate hazard analysis is developed by using the suggested method. The developed system is expected to be useful in finding the propagation path of a fault or the cause of a malfunction as it is capable to approach causes of faults and malfunctions simultaneously.

• Korean Chemical Engineering Research
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• v.58 no.3
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• pp.438-449
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• 2020

This study is to improve the method of calculating the risk of liability that arise from release and dispersion of chemicals outside the plant in process industries such as chemical and petrochemical plants. To achieve this goal, the correlation factors with the risk of chemical release accident is derived by simulating release and dispersion of substances (14 types) designated by Ministry of Environment as preparation for accident, analyzing the cases of chemical release and effects of plant life damage. The method of calculating chemical liability risk was modified and supplemented based on the results obtained from the study. The correlation coefficient between the probit value of 14 chemical types and the liability risk by EURAM (European Union Risk Ranking Method) was -0.526, while the correlation coefficient with the modified chemical release accident risk was 0.319. Thus, the value from modified method shows that they appear to be correlated. According to modified calculating methodology, the correlation between ERPG-2 value and liability risk of 97 chemical types was -0.494 which is 19 times higher than existing liability risk correlation as absolute value. And the correlation coefficient of corrosion risk was 0.91. The standardized regression coefficients (β) value of correlation factors that affected the increase and decrease of risk were derived in order of Corrosion Index(0.713), ERPG-2 (0.400) and NFPA Health Index (0.0680) by values. It is expected that these findings this study result will also enable the calculation of reasonable chemical release liability risk for existing and new chemical, and will help use them as quantitative liability risk management indicators for chemical plant site.

• Journal of the Korean Institute of Gas
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• v.7 no.1 s.18
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• pp.1-9
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• 2003

A Multi-distinction Equipment Screening Algorithm (MESA) is proposed. It selectively integrates Dow's F&EI as its process hazard index technique and ESA (Equipment Screening Algorithm) as qualitative hazard classification technique, and retrieves a detailed list of hazardous equipments with the total hazard indices of those equipments. The inherent expert system, which includes the accident scenarios of the equipments and processes and experts' views of them, narrows further down the list of hazardous equipments and recommends only the most notable candidates. Through the case study of distinguishing the hazardous ranking of the equipments of the LPG underground storage process, using the expert system or not, the applicability of MESA has been validated. Taking the characteristics of the process equipments with hazardous ranking in the point of process intrinsic safety, this proposed algorithm would contribute to providing engineers or managers with information on constructing safely devices and mitigation devices and on scheduling emergency response planning.

• Tribology and Lubricants
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• v.32 no.2
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• pp.56-60
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• 2016

Sapphire has a high hardness and strength and chemical stability as a superior material. It is used mainly as a material for a semiconductor as well as LED. Recently, the cover glass industry used by a sapphire is getting a lot of attention. The sapphire substrate is manufactured through ingot sawing, lapping, diamond mechanical polishing (DMP) and chemical mechanical polishing (CMP) process. DMP is an important process to ensure the surface quality of several nm for CMP process as well as to determine the final form accuracy of the substrate. In DMP process, the material removal is achieved by using the mechanical energy of the relative motion to each other in the state that the diamond slurry is disposed between the sapphire substrate and the polishing platen. The polishing platen is one of the most important factors that determine the material removal characteristics in DMP. Especially, it is known that the geometric characteristics of the polishing platen affects the material removal amount and its distribution. This paper investigated the material removal characteristics and the effects of the polishing platen groove in sapphire DMP. The experiments were preliminarily carried out to evaluate the sapphire material removal characteristics according to process parameters such as pressure, relative velocity and so on. In the experiment, the monitoring apparatus was applied to analyze process phenomena in accordance with the processing conditions. From the experimental results, the correlation was analyzed among process parameters, polishing phenomena and the material removal characteristics. The material removal equation based on phenomenological factors could be derived. And the experiment was followed to investigate the effects of platen groove on material removal characteristics.

• Safety and Health at Work
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• v.2 no.3
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• pp.260-272
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• 2011

Objectives: The promotion of health and safety (H&S) awareness among hospital staff can be applied through various methods. The aim of this study was to assess the risk level of physical hazards in the hospital sector by combining workers' perception, experts' evaluation and objective measurements. Methods: A cross-sectional study was designed using multiple triangulation. Hospital staff (n = 447) filled in an H&S questionnaire in a general hospital in Athens and an oncology one in Thessaloniki. Experts observed and filled in a checklist on H&S in the various departments of the two hospitals. Lighting, noise and microclimate measurements were performed. Results: The staff's perception of risk was higher than that of the experts in many cases. The measured risk levels were low to medium. In cases of high-risk noise and lighting, staff and experts agreed. Staff's perception of risk was influenced by hospital's department, hospital's service, years of working experience and level of education. Therefore, these factors should be taken into account in future studies aimed at increasing the participation of hospital workers. Conclusion: This study confirmed the usefulness of staff participation in the risk assessment process, despite the tendency for staff to overestimate the risk level of physical hazards. The combination of combining staff perception, experts' evaluation and objective measures in the risk assessment process increases the efficiency of risk management in the hospital environment and the enforcement of relevant legislation.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.51-57
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• 2019

A plant layout problem has a large impact on the overall construction cost of a plant. When determining a plant layout, various constraints associating with safety, environment, sufficient maintenance area, passages for workers, etc have to be considered together. In general plant layout problems, the main goal is to minimize the length of piping connecting equipments as satisfying various constraints. Since the process may suffer from the heat and friction loss, the piping length between equipments should be shorter. This problem can be represented by the mathematical formulation and the optimal solutions can be investigated by an optimization solver. General researches have overlooked many constraints such as maintenance spaces and safety distances between equipments. And, previous researches have tested benchmark processes. What the lack of general researches is that there is no realistic comparison. In this study, the plant layout of a real industrial C3MR (Propane precooling Mixed Refrigerant) process is studied. A MILP (Mixed Integer Linear Programming) including various constraints is developed. To avoid the violation of constraints, penalty functions are introduced. However, conventional optimization solvers handling the derivatives of an objective functions can not solve this problem due to the complexities of equations. Therefore, the PSO (Particle Swarm Optimization), which investigate an optimal solutions without differential equations, is selected to solve this problem. The results show that a proposed method contributes to saving the capital expenditures.

• Proceedings of KOSOMES biannual meeting
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• 2003.05a
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• pp.205-209
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• 2003

The various pretreatment processes were evaluated for removal of oil pollutants with weathered oil contaminated seawater in a reverse osmosis desalination process. Weathered oil contaminated seawater was made by biodegradation and photooxidation with oil containing seawater. Coagulation, ultrafiltration, advanced oxidation processes and granular activated carbon filtration was used with pretreatment for dissolved organic carbon. Crude oil was removed but. weathered oil contaminated seawater was not removed by biodegradation and coagulation. DOC and E260 was removed with about 20 % and 40 % by membrane filter of cut off molecular weight 500. So, the most of dissolved organic carbon in weathered oil contaminated seawater was revealed that molecular weight was lower than 500. It is difficult to remove DOC in weathered oil contaminated seawater by advanced oxidation processes treatment, but, E260 was removed more high. However, DOC in weathered oil contaminated seawater was easily adsorbed to GAC. It is revealed that DOC was removed by adsorption.

• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.613-619
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• 2014

A flare system is a very important system that crucially affects on the process safety in chemical plants. If a flare system is designed too small, it cannot prevent catastrophic accidents of a chemical plant. On the other hand, if a flare system is designed too large, it will waste resources. Therefore, reasonable relief load estimation has been a crucial issue in the industry. American Petroleum Institute (API) suggests basic guidelines for relief load estimation, and a lot of engineering companies have developed their own relief load estimation methods that use an unbalanced heat and material method. However, these methods have to involve lots of conservative assumptions that lead to an overestimation of relief loads. In this study, the new design procedure for a flare system based on dynamic simulation was proposed in order to avoid the overestimation of relief loads. The relief load of a deethanizer process was tested to verify the performance of the proposed design procedure.

• Journal of the Korean Society of Safety
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• v.9 no.1
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• pp.155-160
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• 1994

A study of stream pollution caused by construction of the Industrial Complex in Agricultural Area of Chung Chong Nam Do were descrived here. The five main results of this studies are summerized. First, since 1988, among the companies moved in the industrial complex area, the number of electric and electronic companies have increased compared with food companies requiring much BOD. This Is very desirable to reduce the water pollution. Second, the average Biochemical Oxygen Demand(BOD) of Masan stream was the highest and it was decreased in the order of Yudug, Jo and Jungan stream. Third, although the concentration of heavy metals such as Cd and C $r^{6+}$ are not off the limit and the amount of it is small, it is desirable to introduce a chemical process to remove these metals. Fourth, since the wastewater from industrial complex area is the major factor in stream pollution, the laws associated with environmental protection should be enforced even then if the Industrial complex area with food and chemical companies produce wastewater less than 500ton/day. Fifth, it is required to improve a facilities which separete living wastewater from inderstrial wastewater In Kaya-gok and Nojang industrial complex areas.