Purpose. Improvement of the half-face respirator insulating properties testing procedure according to EN 140 standard. Methodology. The filtering half-masks have been tested on ten testees with the mounted simulators of filters on sodium chlorine and paraffin oil test-aerosols. During the test, it was required to perform seven 2-minute exercises. Findings. The technique for testing the insulating properties of half-face respirator taking into account air inflow along the obturation line has been developed. It is based on the comparison of the values of aspiration resistance of the respirators on a tightly sealed half-face respirator with a half-face respirator having small tubes of certain size and diameter inserted into the obturation line to simulate gaps. The difference between these aspiration resistances allows determining the value of the gap between the respirator and testee's face. Moreover, the results indicating the dependence of the protective efficiency on the location of the air inflows along the obturation line were presented. Originality. The dependence of the coefficient of test-aerosol penetration upon the value of airflow resistance of the filter and the location of the air inflow gap has been determined. Various dynamics of flows can be observed under the respirator and the location of the gaps near cheeks markedly affects the penetration coefficient. Practical value. The technique for measuring insulating properties of half-face respirators has been developed. It has been determined that the gaps to a maximum of 1 mm along the obturator do not affect the protective efficiency of the respirator.

Індекс рубрикатора НБУВ: И183-532

Рубрики:

Гірничорятувальна справа

Шифр НБУВ: Ж16377 Пошук видання у каталогах НБУВ 

Важливою характеристикою респіратора є здатність його напівмаски захищати органи дихання від різноманітних забруднень в атмосфері за рахунок щільного прилягання до обличчя. Одним з низьковартісних і простих методів альтернатив діагностики захисних властивостей напівмасок за допомогою спеціальних тест-аерозолів є підтримання постійного перепаду тиску під маскою. Він базується на визначенні кількості повітря, що підсмоктується через щілини, при створенні розрядження у підмасочному просторі. Однак, немає рекомендацій щодо можливостей цього методу в оцінюванні ізолюючих властивостей легких фільтруючих напівмасок, з-під яких не можна відкачати повітря. Мета роботи - розробити спрощений метод оцінювання захисних властивостей напівмасок з використанням вимірювання ступеню розрідження повітря під фільтрувальною напівмаскою, який дозволяє встановити її ізолюючі властивості та коефіцієнт захисту. Коефіцієнт захисту респіратора можна оцінити за кількістю повітря, що проходить через фільтруючий матеріал і щілини з відомим коефіцієнтом проникнення і підсосу. Останній обчислюється як коефіцієнт аспірації в щілину відомої довжини. Витрати повітря визначаються експериментально за різницею тисків між герметично розташованою напівмаскою на манекені та розташованими по її периметру обтюрації трубочками з відомим діаметром. Побудована калібрувальна шкала взаємозв'язку перепадів тиску і витрат повітря через зазор для фільтруючих напівмасок. Розраховано коефіцієнти ізоляції та захисту респіраторів типу "Лепесток". Встановлено, що коефіцієнт захисту прямопропорційно залежить від співвідношення витрат повітря через фільтр і щілини між обличчям і напівмаскою по смузі обтюрації. Висновки: доведено, що метод визначення захисних властивостей фільтруючих напівмасок вимірюванням перепадів тиску можна використовувати як альтернативу високовартісній діагностиці якості засобів індивідуального захисту органів дихання, а також застосовувати при підборі та навчанні працівників правильній експлуатації респіраторів на виробництві відповідно до вимог ЕN529:2006.

Індекс рубрикатора НБУВ: И31 н6 + Р124.504

Рубрики:

Розробка родовищ вугілля і вуглистих корисних копалин

Гігієна праці в гірничій промисловості (загальні роботи)

Шифр НБУВ: Ж16377 Пошук видання у каталогах НБУВ 

Purpose. To ensure the effective functioning of the area for diagnosis and repair of tractive electric vehicle (EV) battery by determining the technical and economic indicators of the production capacity of the enterprise. Methodology. Modelling the process of repairing section of the EV traction battery is performed using the main principles of the queuing system, the graph theory. While calculating the probability-time characteristics and determining the production capacity of the site, the methods of mathematical statistics and probability theory were involved. Findings. With the use of systematic approach, the EV market in Ukraine and the dynamics of the demand over the past three years have been studied. There was collected and analyzed information about issues related to the EV operation, and the most common ones were identified. Empirically, there was obtained an estimate for the duration of the process of repairing and replacing the EV traction battery, as well as the cost of basic operations. The battery repair section of the traction battery is represented as a multichannel queuing system, assuming that the flow of applications for diagnosing and repair is Poisson's flow, and the random process is Markovian. The problem of rational organization of the EV traction battery repair site has been solved by determining the minimum number of repair posts, at which the queue will not grow indefinitely (if customers can wait for their service for a long time and do not leave the queue). The number of repair posts was estimated for the traction battery, which in the existing conditions will allow organizing technical customer service effectively, minimizing the total economic losses from downtime of process equipment and refusals of applications for repairs. Originality. The use of models and methods of the queuing system for the calculation of technical and economic indicators of the production capacity of the traction battery repair section allowed taking into account the stochastic nature of the needs for repaire, and determining the optimal values of those characteristics that ensure the efficient performance of the EV repair section. Practical value. The proposed method for determining the production capacity of the repair section of traction battery is used in solving problems related to the selection and rational placement of technological equipment when designing or upgrading a workshop.

Purpose. To determine the dependence between the design parameters (diameter and height) of a filtering box, the gas filter resistance and the protective power time. Methodology. The calculation results of the filter sorption capacity for the specified organic compound are obtained involving classic statements of the theory of monomolecular adsorption. Experimental studies of gas filters were carried out according to DSTU EN 13274-3:2005 "Respiratory protective devices. Testing methods". Findings. It is shown that in terms of the similar sorbent volume and dimensions of the outlet of a filtering box with the exhale valve, the increasing filter area reduces considerably the breathing resistance; however, that results in the reduced protective time of a gas respirator. It has been determined that in this case an increased filter area causes nonuniform distribution of the filtration rate over the filter area and, as a result, nonuniform use of the filter sections. A section in front of the outlet experiences the greatest load in terms of sorption of the harmful gases. Originality. It has been specified that the increase in the outlet diameter relative to the filter diameter prolongs the protective time of a filter in terms of the same sorbent volume. Practical value. Dimensions of a filtering box have been identified to provide uniform use of the sorbent and maximum protective time.

Purpose. Improvement of efficiency of organizing the work of an electric vehicle (EV) service station (SS) due to the rational distribution of its resources. Methodology. System analysis of technological processes of diagnosing EVs depending on customer needs; mathematical modeling, operations research, combinatorial optimization. Findings. An analysis of technological processes of diagnosing EVs is carried out. The information about the basic services provided by the electric vehicle service station is collected and systemized. For each of them it is established what processes constitute the service, their resources, how many of them operate and the duration of each operation. Mathematical models are built to organize the operation of an EV SS, which allow ensuring a uniform load of available resources and determining the time for the next service. A model problem to reserve resources to serve the largest number of clients is resolved. The proposed mathematical model is generic so that it can be used by any service enterprise that seeks to rationally distribute its resources while providing services to a large number of customers. Originality. It has been found that the efficiency of a service station is increased by reducing the downtime of equipment or human resources, as well as by serving the largest number of customers who contacted a service company. Practical value. A mathematical model is proposed that will allow, first, tracking the employment of resources; second, increasing the throughput by the rational usage of resources.

Серед професійних захворювань хвороби органів дихання є найрозповсюдженішими в світі, основною причиною виникнення яких є забруднення робочої зони шкідливими аерозолями та використання невідповідних антропометричним розмірам обличчя засобів індивідуального захисту органів дихання. Проблематика. Ефективність фільтрувальних респіраторів залежить від двох компонентів: часу захисної дії фільтрів та ізольованих властивостей півмасок. Це вимагає проведення відповідних досліджень для побудови конструкцій півмасок, які дозволять забезпечити високі ізоляційні властивості. Мета роботи - підвищення захисної дії фільтрувальних респіраторів шляхом удосконалення їхньої конструкції, яка відповідає антропометричним параметрам обличь. Матеріали й методи. Для побудови поверхні півмаски застосовано рівняння вільної енергії вигнутої довільної пластинки, яке описується двовимірною сплайн-поверхнею, а її невідомі коефіцієнти встановлюють методом лінійної інтерполяції на основі даних тривимірних координат ключових точок антропометричних рис обличчя. Результати. Визначено закономірності формування поверхні півмаски, грунтуючись на даних тривимірних координат ключових точок антропометричних параметрів обличчя. Розроблено метод вимірювання температури поверхні обтюратора тепловізором на основі опрацювання вихідних сигналів, що дозволяє здійснювати оперативний контроль місць утворення зазорів уздовж смуги обтюрації, виявляти погіршення ізолювальних властивостей протипилового респіратора та обчислювати коефіцієнт його захисту. Висновки: розроблено алгоритм проєктування півмасок з урахуванням результатів 3D-сканування обличь, створення цифрових моделей голови та на їхній основі - поверхні півмасок і конструкції обтюратора. Визначено раціональні параметри фільтрувальної коробки, розміру вихідного отвору для забезпечення мінімального перепаду тиску та рівномірного розподілу пилового осаду на фільтрувальній поверхні.

Purpose. To develop a model of the integrated system for company management, basing on the integration of the quality control and labour safety systems that differs from the known ones by combination of the processes based on the increase in the level of corporate safety cultures within a company. Methodology. Formation of the basis for integration of the quality control and labour safety systems relies on the complex use of system analysis methods that, in combination with Deming and Shewhart cycle and with the performance of corresponding estimation and analysis of the organizational and safety cultures, help plan the practices, procedures, and resources for stage-by-stage combination of the systems as well as maintain the obtained results. Findings. An approach for efficient development of the integrated management system has been proposed on the basis of the analysis of levels of organizational and safety cultures; in future, this will help select such tools and practices that will allow having painless stage-by-stage combination of the available systems of quality control and labour safety with the substantiation of the necessary recourses. It has been established that a key element of the combination is readiness and motivation of not only top management but also linear management and ordinary workers to accept new technologies, approaches, and practices aimed at integration of those cultures, which is provided by the efficient staff involvement by means of corresponding training and constant communication to form the risk-oriented thinking. Originality. A structure and model of the integrated system of quality and safety management as a unified interdependent mechanism have been proposed on the basis of the combination of organizational and safety cultures; that has allowed forming the unified principles for the development of a combined management system. Practical value. The control parameters have been determined to identify stages of integration of the quality control and labour safety systems basing on the attitude to values and formed worldview as well as on the gaining the necessary competences by the workers.

Purpose. To determine the correlation between adhesion tightness of filtering half-masks and anthropometric indices of employees' faces. Methodology. To study tightness of the half-mask adhesion to a user's face, a coefficient of NaCl aerosol test was determined in accordance with the requirements by DSTU EN 149:2017 (EN 149:2001 + A1:2009, IDT). Volunteers took part in the testing selected in keeping with the parametric table divided into 12 settings along the face length and across its width. The tests were carried out using Respi and Standart respirators produced in lots by SPE Standart ltd. Findings. It has been identified that the tested filtering half-masks correspond to the standards by DSTU EN 149:2017 (EN 149:2001 + A1:2009, IDT) and provide adequate protection of respiratory organs of users against harmful aerosols. It has been demonstrated that the required half-mask adhesion to a face depends upon the obturator design, half-mask geometry, and stretching force of a headband. It has been proved that employees with small faces require the instrumental verification of the preferred half-mask while selecting respiratory protective equipment. In turn, for users with large faces quality control is quite sufficient by means of any suitable method described by DSTU EN 529:2006 (EN 529:2005, IDT). Individuals with large faces have demonstrated the greatest values of the tightness coefficient of filtering half-mask adhesion. Originality. It is represented by the scientific substantiation of the tightness coefficient of filtering half-mask adhesion upon the length and width of users' faces. Practical value. Mathematical expressions have been derived making it possible to calculate the tightness coefficient of the half-mask adhesion relying upon the face size. The abovementioned will help assess preliminarily protective characteristics of respirators without specific laboratory equipment.

Шифр НБУВ: Ж16377 Пошук видання у каталогах НБУВ 

Purpose. To improve the approach to the development of a safe work system, one of the important elements of the occupational health and safety management system (OHSMS) of employees at an enterprise. Methodology. The research is based on the "Safe Systems of Work", which combines the content of safe procedures, which are determined taking into account the content of the worker's production task when performing production activities, his/her competence in understanding the technological process and characteristics involved technological equipment. Findings. To reduce occupational diseases and industrial injuries at enterprises, it is proposed to implement the "Safe Systems of Work" (SSW) of "5 steps": "analyse", "summarize", "anticipate", "support", "improve", which will make it possible to identify occupational risks (OR) and justify the feasibility of reducing their impact on the worker during the performance of production activities. For the implementation of each step, a corresponding procedure is provided, which allows ensuring their implementation. It is proposed to carry out the OR evaluation procedure according to the "Tree Trunk Analysis" model, which is a section of the trunk of a tree divided into six parts which characterize the dangerous factors that affect the activity of the employee, the functioning of the technological equipment and the environment. A feature of the proposed approach is the establishment of zones of interaction between the following components of the proposed SSW: the worker and technological equipment, the worker and the environment, as well as the environment and technological equipment, which characterize the specified external and internal factors of influence on the SSW. Originality. The approach to the organization of SSW to reduce the level of OR during the performance of production activities has been improved based on the improvement of the OR management process, the identification of external and internal dangerous factors that affect the level of OR, the probability of the occurrence of a dangerous event and its degree of severity, taking into account changes, over time, in the conditions of performing professional activities: during stable work, during an emergency situation, during an accident and during martial law. Practical value. Improved labour protection instructions or maps of safe production processes can be applied at enterprises with the aim of better perception by employees of labour safety requirements and improvement of document flow at the workplace.

Purpose. Improving the process of managing occupational risk (OR) in occupational safety and health management systems, due to the distribution of dangerous factors which increase the probability of a dangerous event into several phases: before the occurrence of a dangerous event and after its occurrence. Methodology. The method of morphological analysis is used, which is based on the selection of possible solutions for individual parts of the task based on several morphological typical features important for the problem being solved, and the compilation of all possible combinations of hazardous factors and precautionary measures that will allow reducing the amount of occupational risk. Findings. A new approach to occupational risk management is proposed, which involves the division of all dangerous factors into several phases: before the occurrence of a dangerous event, after its occurrence, provision of pre-medical assistance, provision of emergency and medical care. Typical dangerous factors are defined that increase the probability of the occurrence of a dangerous event, which relate to the first phase (before the occurrence of a dangerous event), as well as dangerous factors that affect the severity of accidents and are characteristic of the second, third and fourth phases (after the occurrence of a dangerous event). A concept was developed for calculating the magnitude of occupational risks, based on the consequences of the occurrence of a dangerous event or by the type of injury with the area of responsibility of the enterprise; from the consequences of pre-medical care or the condition of an injured person with the area of responsibility of the enterprise and with the consequences of emergency and inpatient medical care or the state of loss of health of the employee with the area of responsibility of the medical institution. The hierarchy of preventive measures has been improved due to the addition of protective measures consisting of pre-medical care, emergency medical care, in-patient medical care. Originality. When assessing professional risks, it is proposed to determine the amount in accordance with the area of responsibility of the enterprise and and medical institution taking into account dangerous factors corresponding to a specific phase. Practical value. Examples of three matrices for assessing the occupational risk have been developed, taking into account the classification of the severity of the consequences for the health of the employee, which occurred immediately after the occurrence of a dangerous event (accident), after the provision of pre-medical care and after the provision of emergency and medical care. A description of preventive actions to reduce the severity of the consequences is proposed, taking into account the sphere of responsibility.

Purpose. Development of a mathematical model of the air flow movement in a motorized filter respirator (hereinafter referred to as MFR), which allows ensuring the control of the fan parameters, taking into account external and internal influences on the duration of the protective action and favourable operating conditions. Methodology. To describe linear objects of the "input-output" type, it is convenient to use their transfer functions as mathematical models. In this case, to determine the mathematical description of the MFR operation, two tasks need to be solved. The first is related to finding the structure of the mathematical model, and the second involves determining the coefficients of the polynomials in the numerator and denominator of the transfer function that describes the motion of the air flow in the MFR. Findings. A mathematical model of airflow in a MFR has been developed in the form of a transfer function of the third order; it can be used to develop a pressure control system for the air in the under-mask space in accordance with the user's work mode in order ensure comfortable working conditions. The presented mathematical model of airflow in the MFR differs from the existing approaches by taking into account the influence of the following external and internal parameters of the system on the performance indicators: the user's work mode, atmospheric pressure, filter resistance, pressure drop in air ducts with the effect of air accumulation in the under-mask space based on the "capacity-resistance" principle. Numerical coefficients of the mathematical model of airflow in the air duct of the MFR have been determined, which allow adjusting the number of fan rotations according to the time of operation, the increase in resistance on the filters, and the operating mode. Originality. A correlation has been established between the external and internal parameters of the MFR: atmospheric pressure, pressure drop in the air duct, filter resistance, and the user's work mode with the effect of air accumulation in the sub-mask space reflected according to the "capacity-resistance" principle. Practical value. The parameters of the mathematical model have been determined, which can be used when developing a control system for the airflow movement in the MFR: changes in air flow rate in accordance with different conditions of physical exertion of the user when performing professional activities.

Purpose. To improve the process of managing dynamic occupational risks, which considers changes in time in hazardous factors of the organization's environment in the occupational safety and health management system. Methodology. To improve the process of managing occupational risks, we have applied a well-known "Bow-Tie" model (ISO 31010:2018). The model allows assessing occupational risks as the product of the probability of hazardous event occurrence and severity of the consequences, taking into account the influence of hazardous external and internal factors, hazardous actions or dangerous inactions, which, according to the requirements of Clause 4.1 of the ISO 45001:2018 standard, are interconnected and subject to the influence of time. Findings. A model of the connection of hazardous factors of the internal and external environment of an organization, related to their negative influence on the growing probability of hazardous event (incident) occurrence and a degree of severity in time, has been developed. The process of managing occupational risks is proposed, taking into account changes in the time of exposure to hazardous factors, which will allow determining the acceptability or unacceptability of the occupational risk in time. The analysis of changes in occupational risks is proposed to be considered in the following time intervals (specifically in those where there is a corresponding change in risk factors): time of the day, day of the week, month of the year, quarter, half year, year, years etc. All the proposed professional risks were divided into two groups of professional risks considering the changes in their levels in time: static and dynamic ones. To calculate the occupational risk level, it is also proposed to determine all combinations of hazardous factors that can occur simultaneously in time within the corresponding intervals of the time under analysis. Originality. It has been determined that identification of the acceptable level of an occupational risk in the maximum combination of all hazardous factors acting simultaneously at a certain point in time will lead to the fact that all other combinations of hazardous factors will also have an acceptable level of occupational risk. This provision follows from the fact that the level of occupational risk from a smaller number of hazardous factors will not exceed the indicator of occupational risk from the exposure to a larger number of hazardous factors in time. Practical value. The forms for dynamic occupational risk assessment have been developed; a matrix has been proposed for determining the number of combinations of hazardous factors acting simultaneously in time.