Measures of ventilation on efficiency. Ventilation check: We estimate the effectiveness of different methods
Ventilation in industrial premises is an extremely important and effective means of protecting the health of working and disease prevention.
In the production premises, many technological processes are accompanied by heat release, moisture, harmful substances in the form of vapors, gases and dust. Along with this, the air of the premises is constantly contaminated by the exhaled man with carbon dioxide gas, sweat decomposition products, sebaceous glands, organic substancescontained in clothing and shoes, as well as chemical substances that are released from polymeric materials. To maintain the specified aircraft parameters in the room, a fresh and removal of contaminated air is required.
Air of chemical-pharmaceutical enterprises and pharmacy production premises It can be contaminated in the process of make up and issuing drugs during a chemical analysis of prepared drugs. For example, with suspension, dosage, perspiration, packaging, chemical analysis of drugs in assistant, filling, in the room, the air-analyte room is polluted with dust, pairs and gases of medicinal substances. In the washing, distillation-sterilization air may contain excess heat and moisture. Long stay of a large number of people in the premises of the shopping hall causes changes in physical properties and chemical composition air (
perats, humidity, carbon dioxide content, number of microorganisms, etc.).
Maintaining in the industrial premises of the parameters of the air environment satisfying hygienic requirementsis carried out by various ventilation systems, when designing which the quantities of distinguished harm are taken into account.
Industrial ventilation occupies an important place in the complex of preventive measures to improve the air environment of industrial premises aimed at improving the working conditions of workers. Its direct appointment is to combat excess heat and moisture, as well as gases, vapors and dust.
According to the method of moving air distinguish systems of natural, mechanical and mixed ventilation.
Air motion motion in natural ventilation is the wind pressure on the wall of the building (wind pressure),conserving air movement through the room in the horizontal direction, and the difference in temperature indoors and outside (thermal pressure),by moving the convection currents of air vertically and removing heated, contaminated air through holes at the top of the room.
Natural ventilation can be applied in the form through ventilationcarried out by wind pressure, and in the form of controlled ventilation - aeration.Through ventilation is usually used in industrial premises with a large number of working and in the absence of harmful discharge (toxic dust, vapor and gases). Aeration is used only in premises with excessive heat (so-called hot shops) with heat release of more than 23 W / m 3. The outer air at aeration enters the room through open window openings and fraamuga, and the contaminated, carrying out excess heat, moisture, production dust, is removed from the workshop through the top openings or special devices. Local natural exhaust ventilation is organized in the form of exhaust mines (pipes) located above the selection of hot steam and gases (heating furnaces, blacksmith Horn) and bred on the roof of the building. To increase the efficiency of natural hood inside the exhaust mines, deflectors of various designs are installed.
The motion motion in terms of mechanical ventilation serve special devices (fans, ejectors).
Mechanical ventilation is divided into the direction of the air flow to the supply and exhaust. They can be in the form of general (generally exchange) and local (local) ventilation. Community ventilation is designed to create optimal and permissible meteorological conditions in the entire room. It is usually applied if jobs are uniformly located around the room, and harmful discharges come into directly in the air of the working area. The incoming air should be distributed evenly throughout the size of the room.
Complete openings of general ventilation,as a rule, air is fed into the lower (working) area of \u200b\u200bthe room. Air supply to the upper zone is possible in two cases: if there is permanent dust sources in the room (in order to avoid lifting dust) and water vapor, which can be condensed in the cool supply air, so air is supplied heated to 30-35? C in the upper room area . Local supply ventilation(In combination with aeration or mechanical supply-exhaust ventilation), it is used, as a rule, in hot shops in the form "Air Soul",feeding cool (18? C) Air directly on a working person, "Air Oasis",representing a watery-fledged place of rest of the workers, inside which is served cool air, as well as in the form of "Air thermal curtain"(Flood warm air Not higher than 50-70? With in the door exterior openings of industrial premises and the outer goal). The air vents of the air from the gaps or holes of the air and air conduction curtains should be at the outer doors not more than 8 m / s and at the gate - 25 m / s.
Exhaust ventilationdesigned to remove contaminated by harmful air selections from the room, for example, from a washing pharmacy, a room of an analytics chemist.
Total exhaust ventilationremoves polluted air from the upper zone of industrial premises. Local exhaust ventilationit is used directly in places of extraction of harmful substances generated under a number of operations (weighing, dosing, loading, etc.), to prevent them all over the room. Local exhaust ventilation is the most effective way Combating excess heat and moisture executions, gases, couples, dust. Since the concentration of harmful discharges at higher education is higher, consumption
the air to remove them requires significantly smaller than when communicating ventilation.
Local complishes must meet the following requirements: high tightness, convenience of service, resistance to aggression media, small air costs, high efficiency of harmful substances. Local Dance Designs can be completely closed, semi-openor open.The most efficient closed suction. They capture harmful substances as fully as possible with the minimum volume of the air removed. These include housings, cameras, hermetically or tightly shelting dusting equipment. In some cases, shelter sealing is impossible to carry out technological reasons. In these cases, suction with partial shelter (pull out drobe)or open: exhaust umbrellas, exhaust panels, onboard suctions and other devices. Exhaust cabinetsalmost completely covers the source of harmful discharge. Only working openings remain unburned, through which the air from the room enters the closet. Exhaust umbrellasused to capture harmful discharges raising up. Umbrellas are installed above the accumulation of sources of heat and moisture executions and other sources of non-toxic harms that are distinguished together with heat. Whiswing panelsused to remove harmful discharge when the zone of harmful discharge is relatively large and more complete shelter is impossible. On-board suctioninstalled around the perimeter of open baths containing technical solutions from the surface of which harmful pairs and gases are distinguished. The principle of operation of these suits is that the trim air captures harmful pairs, gases and takes them into an exhaust air duct.
There are direct and indirect methods for evaluating the efficiency of ventilation systems..
An assessment of the indirect methods is an assessment of the compliance of the air environment of the production facilities by sanitary standards in terms of the concentration of harmful substances in the air of the working area, temperature, relative humidity and air mobility of thermal irradiation, to direct methods - the speed and temperature of air flow, productivity, developed pressure and the number of revolutions Fan, pressure difference or vacuum, noise and vibration of ventilation systems, concentration of harmful substances in flow air.
After carrying out the hygienic efficiency of ventilation, after the implementation of all necessary technological, operational and organizational measures to eliminate or reduce excess of excess heat, dust and gases from equipment in the premises.
A representative of Rospotrebnadzor before the control of ventilation systems should become familiar with the following documents: approved in installed manner A project of ventilation, as well as a list of digressions from the project, acts of inspection and acceptance of hidden works, technical testing protocols and adjustment of ventilation systems, passports of ventilation systems, schedules of planning and warning repair and its logging.
Checking the efficiency of the operation of the active ventilation is carried out by measuring the speed and temperature of air flow in work zoneIn open openings and work sections of air-actuating devices, as well as in transport, installation and aeration openings, in the supply jets from air-distribution devices, air shower and curtains. In addition, the performance of fans and pressures developed in ducts in the ducts of secrets and exhaust systems built into the equipment of local suits and aspiration shelters and is measured by the difference in pressure or vacuum in the industrial premises of relatively adjacent rooms or atmospheric, in boxes, cabins and shelters.
Performance of ventilation systems of local suns, aspiration shelters, etc. Determined by the formula:
To estimate the performance of mechanical ventilation, the speed of the air passing through the closed air duct is determined by the magnitude of the pressure generated by air moving along the air duct, by the formula:
Dynamic pressure (n din) is the pressure difference required to move air through the air duct.
Dynamic pressure in the air ducts is measured by micromanometer MMN-2400- (5) -1.0, thermomemometer (TESTO-435), pressure gauge (differential digital DCM-0.1 / m, liquid U-shaped) complete with a pneumometric tube PITO and DR .
Direct measurement of air flow velocities in channels or air ducts is carried out by thermoenemometers (Testo- 425, LV-110, etc.).
Sanitary and hygienic assessment of ventilation efficiency, indicative base of action.With sanitary and hygienic control mechanical and natural ventilation, as well as local suits of all types, effectiveness is estimated as the ability to maintain the production area of \u200b\u200bthe production premises of the air parameters satisfying the requirements of SanPiN 2.2.4.548-96, ace 2.2.5.1313-03, ace 2.2.5.1314-03.
The sanitary and hygienic assessment of the ventilation of the production premises should be carried out with the participation of representatives of the relevant services of the enterprise: technologists, mechanics, laboratory workers, safety and ventilation service provisions.
The scheme of the mechanical ventilation and air conditioning installations can be represented as follows:
A brief description of the production process and work premises (cubature, number of employees);
The characteristic of the main harm that changes the state of the air environment, the nature of its selection: constant or periodic, localized or scattered;
Ventilation system: Community or localizing, supply-exhaust, recycling;
Mechanical characteristic of the unit: fan number, motor power;
Measures to reduce noise and vibration from the operation of ventilation plants;
The location and sanitary characteristics of the intake air and emission fence places;
Devices for the preparation of the supplied air and their technical specifications (cleaning, heating, etc.);
The location of the supply and exhaust holes in the room;
Temperature and speed of movement of the supplied air (at the duct screw hole);
Description and characteristics of localizing exhaust devices;
Air movement speed in shelter openings;
Description and characteristics of local airborne devices;
The speed and temperature of the air supplied by local supply devices;
Air exchange indoors (separately on the influx and exhaust), the air cube (the number of cubic meters of air, entering 1 operating) and the multiplicity of volume;
Air balance in the room (the ratio of the amount of supplied and removed air);
Characteristic harmful factors premises nearby; the possibility of interpenetration of harm;
The characteristic of the air environment under the action of ventilation and without it:
a) temperature and humidity of air at workplaces (including the characteristic of the uniformity of temperature and humidity at different points of the room, at different distances from the supply and exhaust holes);
b) air movement speed in the workplace, in the aisles at the door, the presence of tangible air currents in the workplace;
c) air dusting (at workplaces);
d) the concentration of harmful gases and vapors (at workplaces). With periodic excavation, it is necessary to specify the maximum amount due to certain points of the production process;
Survey data working on health and, if necessary, the results of physiological monitoring of the heat-regulation process;
Conclusion.
Direct assessment of the efficiency of the ventilation system of the production room begins with preliminary measures: compliance checks technological process the regulations, the health of technological equipment and communications (if there are defects, is given an indication of their elimination), inspection of the ventilation systems and their elements, assessing the correctness of the fan operation (correct direction of rotation, the absence of extraneous noise during rotation), inspection of the aircraft network (for availability breaks and damage in it), air-powered and air intake devices (blinds, lattices, valves, etc.) and calorificates.
After elimination of selected defects, measurements of microclimate parameters are carried out and determining the content of harmful substances in the air of the working area.
Ventilation of the surveyed room is recognized effective if the values \u200b\u200bof the specified parameters are within the requirements of sanitary regulations.
When the air parameters deflects from acceptable values, the ventilation instrumental survey should be proceeded.
Mechanical ventilation performance is measured for: determining the conformity of actual ventilation performance of the project value; calculating the multiplicity of air exchange; identifying the volume of inflows and exhaust and their distribution over the area zones; Calculations of the average air movement rates in the working sections of air-actuate devices.
If the actual values \u200b\u200bcoincide with the design, but do not provide regulated aircraft parameters, then the ventilation of this room is estimated as unsatisfactory, and a labor hygiene specialist should indicate the need to revise the ventilation project, taking into account the actual mode of operation of technological equipment (an increase in equipment intensification, intensification of production processes, introducing new harmful substances into technological cycles, etc.).
If the actual values \u200b\u200bof the ventilation parameters do not coincide with the project, then the order is drawn up to bring the ventilation parameters to project values \u200b\u200bwith an indication of the execution time. After executing the enterprise, the prescription is carried out
re-measure the parameters of the ventilation systems and assessment of the condition of the room of the room.
15.2. Examination of ventilation projects
When examining the project, it is necessary to study its technological part, then check the main calculations and evaluate the project according to the following scheme.
1. Assessing the correctness of the choice of ventilation system.
2. Characteristics and evaluation of the supply system:
The method and place of the intake air fence;
Devices for cleaning, heating and humidifier air;
The location and device of the supply openings indoors;
Temperature and flow rate of supply air;
The adequacy of the air exchange on the influx (its verification calculation);
Cabbage room per person, air cube and metabolism;
The presence of recycling, admissibility and its scale.
3. Evaluation of local air supplies:
Direction of air soul flow;
Air temperature;
Air supply rate.
4. Characteristics and evaluation of the exhaust system:
Device and location of the openings of general exhaust ventilation;
Device of localizing shelters;
Initial air velocity in shelter holes;
Device for cleaning the air removed from the room;
Characteristics of the release of the air removed;
Air exchange hood (its verification calculation).
5. Characteristic and evaluation of the ventilation system as a whole:
The ratio of air supply air intake and emissions of the air removed;
The ratio of the location of the supply and exhaust holes in the room;
Balance of the room (i.e., the ratio of the total amount of supply and removed air).
6. General sanitary assessment of the ventilation system. Conclusion for the ventilation project.
Basic hygienic recommendations in the design and construction of ventilation and contingentization systems. Appointment of ventilation and air conditioning systems in industrial premises - maintaining microclumatic conditions in them in accordance with the requirements of sanitary rules and removal of harmful substances from the air of the working area to the PDC levels.
Task of ventilation to combat excessive heat(The difference in heat generation and heat loss in the room) is to maintain the optimal and permissible temperatures of the air in the room as a whole (with the help of secrerative ventilation) or in limited space Workplace (air souls). To do this, aeration, common natural or mechanical ventilation with a local influx, etc. can be applied in the work premises.
For workshops with significant excess of explicit heat under heat change of more than 23 W / m 3, referring to rooms with significant heat dissipation (the so-called hot workshops), aeration is the cheapest and reliable way Ventilation.
The task of ventilation to combat excess moisture- maintaining the relative humidity of air air levels at the level, depending on other meteorological conditions and the nature of the work, the normal thermal balance of the body. At the same time, ventilation should prevent the formation of the condensation of water vapor (in the air and on the inner surfaces of the fences).
When solving the issue of principles and regimens of ventilating rooms with excessive moisture, first of all, it should be provided for the hermetic local ventilation covers of the voltage-paying units with the removal of excess moisture from them.
In cases where, for some reason, local exhaust devices cannot be used or they cannot provide a sufficiently complete removal of excess moisture, we use secregnate supply and exhaust ventilation at the calculation of the assimilation of excessive moisture to the inlet outer air and removing the moistened air outward.
General principles of combating moisture subject with general ventilation are the supply of heated dry air in
working and upper zones and extraction of wet warm air from the upper room area.
To prevent the condensation of moisture and the formation of drops, it is necessary that the air coolant in external fences has a temperature above the dew point.
To combat harmful couples and gasesthe most effective localizing exhaust ventilation (directly from hermetically covered aggregate highlighting a harmful factor).
In some cases, when according to technological, constructive and other conditions, it is not possible to use local exhaust ventilation, applied generally. With it, clean air is supplied, diluting harmful substances incoming to the PDC. The accumulation of the selected vapors and gases in the upper or lower zones is possible only with relatively large amounts and insignificant air mobility. In the absence of these conditions, diffusion occurs and the active mixing of gases and air in the industrial premises due to the movement of machines, people and the presence of convective thermal currents, and the resulting gas-air mixture almost does not change the specific mass. Under such conditions, the choice of zone to remove the contaminated air will depend mainly from excess in the heat room capable of heat polluted air and raise it up. In general, it is necessary to recommend the extraction of air from the zones, the most close to the venues of the possible excretion of the harm.
Trying air, as a rule, should be submitted to the working area (at an altitude of 1.2-1.5 meters from the floor) to the places of the greatest contamination. In cases where gas divisions are localized by local suction, the air is usually supplied to dispersed in the upper area of \u200b\u200bthe room.
To combat dustthe most efficient local exhaust ventilation removing dust from the zone of its formation. In the ventilation project, measures should be provided for the maximum tooling the source of dust and dusting and the approximation of the suction opening to the dust source.
Fighting dust using general ventilation, as a rule, does not give the necessary hygienic effect. In some cases, when the condensation aerosol is formed (welding) and work is not performed on fixed workplaces, but in different areas
kah shop, removal of dust using local exhaust ventilation It is impossible, it is necessary to use secregnate supply ventilation, designed to dilute the complex welding aerosol (iron, manganese, titanium oxides, etc.).
Supply ventilation system.Exterior air receiving devices should be placed at an altitude of more than 1 m on the level of sustainable snow cover, but not lower than 2 m from the ground level and not lower than 3 m from the ground level in the areas of sandy storms.
Common receiving devices for outdoor air should not be designed for equipment support systemsthat are not allowed to post in one room.
Protection of receiving devices from pollution with suspended impurities of plant origin must be provided in the presence of instructions in the design task.
Consumption of the supply air during the warm season for premises with excess heat should be determined by providing direct or indirect evaporative cooling of the outdoor air and air-airing indoors, in which, under the terms of work, high humidity is required.
Padded air from the air distributors is given, as a rule, to the room with a constant stay of people, for permanent jobs and direct so that the air does not flow through the zones with great pollution in the zone with less contamination and did not violate the work of local suns.
The damping air into the working zone is supplied by horizontal jets produced within or above the working area, including in vortex ventilation, inclined (down) jets produced at an altitude of 2 m and more on the floor, and vertical, produced at an altitude of 4 m and more from gender.
With minor excess warmth, the trim air into production rooms can be supplied to the upper zone by jets: vertical directed from top to bottom, horizontal or inclined (down). In rooms with significant moisters with a heat-smear ratio of 4000 kJ / kg and less, as a rule, part of the supply air in the condensation zone of moisture on the enclosing structures of the building is supplied.
In rooms with dust secretions, the trimming air should be supplied with jets directed from top to bottom from the air-screening agents, which are located in the upper zone.
Ventilation with artificial motivation It is necessary to provide for Cainry cabins in rooms with excess heat of more than 23 W / m 3 and when irradiated with a heat wheel with a heat flux with a surface density of more than 140 W / m 2.
If in the air surrounding the cabin cabin, the concentration of harmful substances exceeds the MPC, then it is necessary to provide a ventilating outer air.
Ceiling fans and fans-faiths (except for applied for scenario of workplaces) should be provided in addition to the supply ventilation systems for a periodic increase in air movement speed in the warm season above the permissible, but not more than 0.3 m / s at workplaces or individual Plots of the room: on permanent workplaces during irradiation with a radiant heat flux with surface density of more than 140 W / m 2.
Local supply installations.Air strokes with outdoor air permanent jobs should be provided:
When irradiated with a radiant heat flux with an intensity of more than 140 W / m 2;
With open technological processes, accompanied by the release of harmful substances, and the impossibility of the shelter device or local exhaust ventilation, providing measures to prevent the proliferation of harmful discharge on permanent jobs. Estimated temperature standards and air velocity at the workplace during air scenario in industrial premises are presented in SNiP 41-01-2003 (Table 15.1).
When evaluating the projects of the air shower, it is necessary to remember the following: thermal irradiation of the head, neck and chest is heavier than the irradiation of the limbs; The more irradiated body surface, the fact of the feeling; Continuous exposure is an intermittent (the state of the worker improves, if during a pause, at least very short-term, it is in conditions favorable for heat transfer).
Radek offers comprehensive services on sites of any category of complexity in Moscow and MO. We have a staff of experienced employees, as well as all the necessary measuring equipment in order to check the efficiency of this engineering network accurately, carefully and in a short time. As a result of the verification, it is determined whether the ventilation system corresponds to valid sanitary, fire and other norms, whether the necessary air exchange is complied with other parameters to be controlled.
Our prices
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Services provided |
Price |
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5000 rubles |
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Measuring the multiplicity of air exchange indoor |
12000 rubles |
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Measuring the multiplicity of air exchange indoor |
10,000 rubles |
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Passportization of the supply / exhaust ventilation system (for 1 system) |
10,000 rubles |
In what cases is required for ventilation systems?
Measuring key parameters of the functioning of ventilation systems are needed in the following cases:
- In the course of commissioning and commissioning. Immediately after the ventilation was mounted, it is necessary to hold it, check and launch it. In addition, new systems are passporting, an integral element Which is a thorough check of operating parameters.
- With reconstruction. Under the reconstruction, it can be understood as a complete replacement of the entire ventilation equipment at the facility and a significant change in the structure (for example, commissioning of the new air conditioning system, due to which the performance indicators of the entire ventilation network significantly changed). After performing work, measurements confirming the compliance of the new system standards.
- During regular periodic monitoring of equipment performance. In accordance with existing standards At various facilities, ventilation systems should be checked with a set periodicity. General principle: The more dangerous technological processes and the stronger safety is associated with the efficiency of the ventilation equipment - the more often the checks are needed. So, in residential buildings such a check can be carried out 1 time in 3 years, while the majority industrial facilities Pass the procedure annually. For the same premises, even the monthly check can be required in the technology.
What parameters are estimated during testing of ventilation systems?
A specific checklist of checks that will be performed on the facility depends on the purpose of this object, technological processes, as well as the composition of the ventilation system. The most typical set can be attributed the following parameters:
- . This is a conditional indicator, which characterizes the amount of full air shift in the room per unit of time (as a rule - per hour). The higher the concentration of harmful substances in the air - the higher the requirements for multiplicity.
- Air pressure in ventilation channels and air ducts (air traffic speed). This indicator allows you to check the correct functioning of the ventilation equipment, including the aggregates of active ventilation - from a simple intra-channel fan to a high-performance chiller.
- Volumetric air flow. At objects where exhaust ventilation is running, diffusers and air distributors are used, it is necessary to estimate which air volume goes to the ventilation grille or an exhaust umbrella per unit of time.
- Individual indoor microclimate performance. It should be understood that testing of ventilation systems and checking the microclimate is different kinds Research. However, some parameters must be determined to assess the efficiency of the equipment. For example, the ventilation system characterizes such an indicator as the air flow rate indoors.
Based on the measurements carried out, the work of engineering systems is concluded: how important the actual indicators correspond sanitary standards, And is it possible to count the ventilation system at the object is sufficient.
How is the work?
To test the operation of equipment, Radek engineers arrive at the object, which bring with them all the necessary equipment. To assess the effectiveness, an electronic balometer can be used, measuring air flow, the thermoemometer used to test the air flow rate and temperature, as well as other equipment. Electronic devices are used to estimate the airflow parameters in ventilation channels and other devices. The work is made according to the following algorithm:
- Preliminary study of technical documentation for the ventilation system. If we are talking about new equipment, preliminary calculations are based on project documentation, if the existing ventilation is taken into account the information recorded in the dataset passport.
- Getting access to Radek specialists directly to the ventilation system. In the course of field research, all performance indicators are evaluated. The parameters received during the checks are entered into protocols. If necessary, examined ventilation channels. All work on the ventilation system is non-destructive and secure for equipment.
- Calculation of settlement values. After the field, the cameral stage is carried out, during which engineers calculate ventilation characteristics and compare them with the regulatory values \u200b\u200bthat are specified in the project documentation or passport. Conclusions are made about the work of the equipment and compliance with the established standards.
- Registration of the act. According to the results of the work carried out, a detailed report on the established methodology is drawn up, in which all certain indicators are given, after which the conclusion is made. If there were no problems, it is concluded that all ventilation elements are functioning correctly, and the ventilation system can be used safely and in accordance with the norms. In case of identifying problems, a list of works aimed at eliminating identified problems will be recommended.
Depending on the characteristics of technological processes, ventilation checks can be carried out or comprehensively (on the entire object) or only in some premises.
Air conditioning and ventilation: Is there a difference from the point of view of verification?
IN modern conditions The ventilation channel can perform air-conditioned air delivery functions. At objects, central air conditioning is increasingly introduced, which works in an inseparable bundle with ventilation.
Therefore, if a similar solution is implemented at the facility, the evaluation work must be carried out comprehensively, evaluating all the parameters of the work. The procedure for estimating the efficiency of the system, in the presence of air conditioning units, is somewhat different, as attention is paid not only to air movement indicators, but also microclimatic characteristics (temperature, air humidity, etc.)
Radek: Your confidence in the proper operation of systems
Our company combines three key benefits: personnel with impressive experience, availability necessary equipment and strict adherence to the norms. As a result, contacting us, you will receive:
- Competent solution in a short time so that you can smoothly use the system. Compiled by our specialists an act will be reliable protection From any claims from the regulatory authorities.
- Minimum trouble. Our experts can work carefully and imperceptibly, therefore checks even on functioning enterprises are made without significant complications for business.
- Carefulness and accuracy of performing all measurements. We will check each ventilation channel and the exit of the lattice, make sure that there are no problems in the operation of systems. Therefore, our check is not just a formality required to verify the protocol, but the ability to identify real problems.
- Impeccable documentation design. Our reports and acts without problems are recognized by government agencies and services, guaranteeing the legal protection of our customers.
To get advice and clarify details regarding the order of this service, call us right now!
Topic 10. Hygienic assessment of industrial ventilation
Topic 10. Hygienic assessment of industrial ventilation
Objective:explore the various types of industrial velocities, hygienic requirements for the organization of ventilation of industrial premises of pharmacies; We will master the methods for determining the necessary air exchange and its multiplicity in various pharmacy premises, hygienic assessment of the effectiveness of ventilation systems.
When preparing for the lesson, it is necessary to work
questions of theory.
1. Sources of air pollution of industrial premises of pharmacies. Appointment and types of ventilation.
2. Natural ventilation, organized and unorganized air exchange, aeration. Factors defining the intensity of ventilation.
3. Artificial ventilation. Ventilation systems. Features of the organization of ventilation in the industrial premises of pharmacies with excretion in the air of excess heat, water vapor, dust, poisonous vapors and gases.
4. Hygienic assessment of the effectiveness of ventilation systems of industrial premises. Determination of the necessary air exchange in various pharmacy premises and its multiplicity.
After mastering the topic the student should know:
Stages of the hygienic examination of production ventilation;
Determination of the necessary air exchange in various pharmacy premises and its multiplicity;
be able to:
Choose the most effective views ventilation for specific production conditions in the premises of pharmacy organizations;
Evaluate the effectiveness of natural and artificial ventilation in the premises of pharmacy organizations on the results of research on compliance with hygienic standards;
Evaluate the effectiveness of the operation of the ventilation systems;
Use main regulations and information sources of reference nature on the use of efficient ventilation systems to ensure optimal and permissible meteorological conditions and purity of pharmacy rooms.
Educational material for assignment
Ventilation in industrial premises is extremely important and effective tool Protection of health and prevention of diseases.
In the production premises, many technological processes are accompanied by heat release, moisture, harmful substances in the form of vapors, gases and dust. Along with this, the air of the premises is constantly contaminated with the exhaled man with carbon dioxide, the products of swelling, sebaceous glands, organic substances contained in clothing and shoes, as well as chemicals separated from polymeric materials. To maintain the specified aircraft parameters in the room, a fresh and removal of contaminated air is required.
The air of chemical-pharmaceutical enterprises and pharmacy industrial premises can be contaminated in the process of corrosion and issuing drugs during the chemical analysis of preparations. For example, with suspension, dosage, crossing, packaging, chemical analysis medicinal preparations In assistant, filling, in the room, the air-analyte room is polluted by dust, pairs and gases of medicinal substances. In the washing, distillation-sterilization air may contain excess heat and moisture. Long stay large number People in the placement of the shopping hall causes changes physical properties and the chemical composition of the air (the
perats, humidity, carbon dioxide content, number of microorganisms, etc.).
Maintaining in the production premises of the parameters of the air environment that satisfies the hygienic requirements is carried out by various ventilation systems, when designing which the amounts of distinguished harm are taken into account.
Industrial ventilation occupies an important place in the complex of preventive measures to improve the air environment of industrial premises aimed at improving the working conditions of workers. Its direct appointment is to combat excess heat and moisture, as well as gases, vapors and dust.
According to the method of moving air distinguish systems of natural, mechanical and mixed ventilation.
Air motion motion in natural ventilation is the wind pressure on the wall of the building (wind pressure),conserving air movement through the room in the horizontal direction, and the difference in temperature indoors and outside (thermal pressure),by moving the convection currents of air vertically and removing heated, contaminated air through holes at the top of the room.
Natural ventilation can be applied in the form through ventilationcarried out by wind pressure, and in the form of controlled ventilation - aeration.Through ventilation is usually used in industrial premises with a large number of working and in the absence of harmful discharge (toxic dust, vapor and gases). Aeration is used only in premises with excessive heat (so-called hot shops) with heat release of more than 23 W / m 3. The outer air at aeration enters the room through open window openings and fraamuga, and the contaminated, carrying out excess heat, moisture, production dust, is removed from the workshop through the top openings or special devices. Local natural exhaust ventilation is organized in the form of exhaust mines (pipes) located above the selection of hot vapors and gases (heating furnaces, blacksmith mines) and bred buildings. To increase the efficiency of natural hood inside the exhaust mines, deflectors of various designs are installed.
The motion motion in terms of mechanical ventilation serve special devices (fans, ejectors).
Mechanical ventilation is divided into the direction of the air flow to the supply and exhaust. They can be in the form of general (generally exchange) and local (local) ventilation. Community ventilation is designed to create optimal and permissible meteorological conditions in the entire room. It is usually applied if jobs are uniformly located around the room, and harmful discharges come into directly in the air of the working area. The incoming air should be distributed evenly throughout the size of the room.
Complete openings of general ventilation, as a rule, air is fed into the lower (working) area of \u200b\u200bthe room. Air supply to the upper zone is possible in two cases: if there is permanent dust sources in the room (in order to avoid lifting dust) and water vapor, which can be condensed in the cool supply air, so air is supplied heated to 30-35? C in the upper room area . Local supply ventilation(In combination with aeration or mechanical supply-exhaust ventilation), it is used, as a rule, in hot shops in the form "Air Soul",feeding cool (18? C) Air directly on a working person, "Air Oasis",representing a watery-fledged place of rest of the workers, inside which is served cool air, as well as in the form of "Air thermal curtain"(flux of warm air is not higher than 50-70? with in the door exterior openings of industrial premises and the outer gate). The air vents of the air from the gaps or holes of the air and air conduction curtains should be at the outer doors not more than 8 m / s and at the gate - 25 m / s.
Exhaust ventilation designed to remove contaminated by harmful air selections from the room, for example, from a washing pharmacy, a room of an analytics chemist.
Total exhaust ventilation removes polluted air from the upper zone of industrial premises. Local exhaust ventilationit is used directly in places of extraction of harmful substances generated under a number of operations (weighing, dosing, loading, etc.), to prevent them all over the room. Local exhaust ventilation is the most efficient way to combat excess heat and volatility, gases, pairs, dust. Since the concentration of harmful discharges at higher education is higher, consumption
the air to remove them requires significantly smaller than when communicating ventilation.
Local complishes must meet the following requirements: high tightness, convenience of service, resistance to aggression media, small air costs, high efficiency of harmful substances. Local Dance Designs can be completely closed, semi-openor open.The most efficient closed suction. They capture harmful substances as fully as possible with the minimum volume of the air removed. These include housings, cameras, hermetically or tightly shelting dusting equipment. In some cases, shelter sealing is impossible to carry out technological reasons. In these cases, suction with partial shelter (pull out drobe)or open: exhaust umbrellas, exhaust panels, onboard suctions and other devices. Exhaust cabinetsalmost completely covers the source of harmful discharge. Only working openings remain unburned, through which the air from the room enters the closet. Exhaust umbrellasused to capture harmful discharges raising up. Umbrellas are installed above the accumulation of sources of heat and moisture executions and other sources of non-toxic harms that are distinguished together with heat. Whiswing panelsused to remove harmful discharge when the zone of harmful discharge is relatively large and more complete shelter is impossible. On-board suctioninstalled around the perimeter of open baths containing technical solutions from the surface of which harmful pairs and gases are distinguished. The principle of operation of these suits is that the trim air captures harmful pairs, gases and takes them into an exhaust air duct.
Features of the ventilation system in pharmacy institutions
In pharmacy institutions, the ventilation and air conditioning systems are considered effective if they are supported by microclumatic conditions in the premises in accordance with the requirements of sanitary regulations and harmful substances from the air of the working area to the MPC levels are removed.
In premises with redundant warmthmost effective is to maintain optimal and permissible air temperatures as a whole due to the general natural (aeration) or mechanical
ventilation using local air inflows in the form of air evidence for individual jobs. For "hot shops" aeration is the cheapest and reliable way of ventilation.
To ensure normal thermal Balance organism in premises with excessive moistureventilation should contribute to the removal of the excess moisture and prevent the formation of water vapor condensation in the air and on the inner surfaces of the fences. For this, the most rational hermetic local exhaust devices in the form of suns. If it is impossible to use their use, consistent supply-exhaust ventilation with the supply of heated dry air into the working and upper zones and the extraction of wet warm air from the upper area of \u200b\u200bthe room.
For removing harmful vapors and gasesthe most effective is the local exhaust ventilation with the organization of the supply of the air intake in the upper area of \u200b\u200bthe room. If it is impossible to use its use, considerable supply ventilation is used, which, when applying clean air into the working area (at an altitude of 1.2-1.5 meters from the floor), helps to dilute the harmful substances to the PDC. Removing the contaminated air in these cases is recommended from the zones, the most close to the highlighting places, and during the excess of heat - from the upper zone, even during the isolated heavy gases and vapors.
To combat S. dustthe only effective means of dedusing is local exhaust ventilation, removing dust from the focus of its formation. In cases where the condensation aerosol is formed or work is performed not at fixed workplaces, it is necessary to use common air ventilation, designed to dilute an aerosol.
The speed of suction of polluted air depends on the dispersion of contaminants and the degree of their toxicity (hazard class). The coarse dust is recommended to remove with a speed of at least 4 m / s, fine - 2 m / s. To remove high-tech vapors and gases, it is recommended to observe the rate of suction of at least 1.5 m / s, for low-toxic - 0.7 m / s. Dust suction air ducts should not have acute corners In places to change their direction and should not be combined with air ducts that remove water vapors or toxic substances, in order to avoid accumulation of dust sediments and blocking air ducts.
The ratio of the total inlet and removed air (air balance)
Balance is considered balancedif the amount of air entering the room is equal to the amount of air, which during this time is removed from the room by exhaust ventilation. If the number of air supplied to the air is larger than the amount of deleted, indoors are created high blood pressure; In this case, the air balance positive.Usually, a positive air balance is used in the rooms where it is undesirable to enter the contaminated air from the adjacent rooms ("clean" rooms: aseptic pharmacy unit) or cold air outside. Due to the excess air pressure in the aseptic unit, the movement of air flow will be directed from this unit into the premises adjacent to it. If more air is removed from the room by exhaust ventilation than is supplied supply ventilation, Balance denied(Premises with harmful discharge).
Also, the aseptic unit is recommended using special equipment to create horizontal or vertical laminar flows of clean air in the entire room or in separate local zones to protect the most responsible sections or operations (clean cameras). Clean chambers or tables with laminar air flow should have surface and saws from a smooth durable material. The speed of the laminar flow - in the range of 0.3-0.6 m / s with regular control of air sterility at least 1 time per month.
Air conditioning. Under air conditioning, it is understood as the creation and automatic maintenance of the constancy of the air indicators, such as temperature, humidity, pressure, gas and ion composition, smell, and air movement speed. A device that carries out the required air treatment (cleaning, heating or cooling, etc.) is called installation of air conditioning, or air conditioning. With the help of air conditioners in rooms, the necessary microclimate is ensured to create the comfort conditions and the normal flow of technological processes.
Features of the training system ventilation air at the enterprises of the pharmaceutical industry
In connection with the introduction of GMP rules in many enterprises of the pharmaceutical industry, one of the main issues is the preparation of so-called pure industrial premises (CPP), or "clean zones" in which the most responsible technological operations Production of drugs.
Clean rooms are the main consumer and part of Air preparation systems. Maintenance possible sources Air Pollution: Personnel, Equipment, Technological Process Election in Air Particles, forming aerosol of solid particles suspended in air, or fog of liquid. To remove particles forming aerosols or fogs, a system of multistage filtering of atmospheric air is intended.
One of the main documents describing the method of multi-stage air filtration is the developed SCC with the participation of the hybrimemide "Typical Ventilation Air Preparation Scheme", upgraded with new requirements
in 2002
The air purification system in the proposed scheme consists of several filters: filter rough Cleaning, Filter of fine cleaning, highly efficient finishing filters. After passing a coarse cleaning filter, the air enters the central air conditioner, where it is consistently exposed to heating, cooling and heating in various sites, then enters the steamotrier and through the fan into the fine cleaning filter, after that - in a highly efficient filter. Then the air enters clean rooms Different zones A, B, C, D, to which the relevant requirements for the content of mechanical particles of 0.5 μm and microorganis content are presented (Table 46). In this embodiment typical scheme A differentiated recycling air return is also carried out, which reduces the cost of air preparation costs. The system works with two air conditioners.
Table 46.Technological parameters of ventilation air in pure industrial premises
Laboratory work "Hygienic assessment of ventilation of industrial premises"
Tasks student
In accordance with the data of the situational problem:
1. Select optimal option Ventilation system for specific production conditions.
2. Determine the performance of the exhaust ventilation system.
3. Determine the multiplicity of air exchange indoor.
Work technique
Determination of the necessary air exchange in industrial premises
The calculation of the magnitude of the supplied and removed air is carried out on the basis of the amount of harmful discharges to be diluted to permissible levels. When calculating the air exchange room, the consumption of the supply air required to absorb excess heat, moisture, harmful substances is determined.
The required amount of air supplied to the room during gas division is calculated by the formula:
If there is not one, but several different harmful ingredients (pairs, gases) in the air of the working area (pairs, gases), the calculation of the performance of sociable ventilation has its own characteristics. So, while highlighting the working area chemical substancesnot possessing a unidirectional nature of toxic action, the volume of secrend \u200b\u200bventilation is calculated separately to dilute each component to the MPC.
With a unidirectional effect of chemicals that simultaneously released into the working area, the calculated air exchange is found by summing the volume of air obtained at the rate of each substance. At the same time, such concentrations (C) are considered to be admissible for design, which satisfy the condition:
The required amount of air supplied to the room during dusting is calculated by the formula:
The calculation of the supply air required to dilute excess heat generations during aeration device is made by the formula:
If the air quality is worsens only as a result of the presence of people, the calculation of the volume of ventilation is carried out by carbon dioxide by the formula:
Definition and evaluation of the effectiveness of ventilation systems
The priority event to ensure favorable meteorological conditions in the premises is effective system Ventilation. Evaluation of the effectiveness of the current ventilation system is reduced to the comparison of the air exchange, which it creates with the regulatory air exchange. The air exchange in the room is found across the multiplicity (k, h -1) - the value showing how many times within an hour the air is completely replaced by clean. Ventilation is considered effective if the multiplicity of valid ventilation (K d) is greater than or equal to the normative (K H).
The value of normative multiplicity is estimated in view of the specifics of the technological process and the type of harmful factors, worsening air quality in the room (gases, pairs, aerosols of toxic substances, heat or moisture - excess, etc.). The regulatory multiple air exchange is in the formula:
K H \u003d L UD / V SV, (2.10)
where L ud is the volume of air to be removed from the room for an hour by sanitary and hygienic requirements, m 3 / h;
V SV - free space, equal to 80% of the geometric volume -
V sv \u003d 0.8vg g, m 3.
When entering the air of gases, vapors or dust, the volume of air removed is found according to the formula:
L UD \u003d G V / (C 1 - C 2), (2.11)
where G V is the amount of harmful substances (gases, vapors or dust) entering the air of the room for an hour, mg / h. This amount can be found according to the formulas given in the literature.
C 1; C 2 - concentration of harmful substances, respectively, in removable and supply air, mg / m 3.
When determining the regulatory air exchange rate with 1 \u003d PDC RZ, from 2 \u003d 0.3 PDK RZ.
Upon admission to the air of several types of harmful substances of unidirectional action (the effect of the summation), the volume of air is found to remove each substance, and they are folded. For substances that do not possess a unidirectional action, the normative takes the maximum of the calculated volumes.
When entering the air of water vapor, the air volume to be deleted is calculated by the formula:
L UD \u003d G Water / (D 1 - D 2), (2.12)
where G water is the number of water vapor entering the air of the room from the technological equipment for an hour, g / h;
d 1, D 2 is the content of water vapor (absolute humidity of air), respectively, in removable and inlet air, g / m 3.
The absolute humidity of air (a, g / m 3) is not much different from the partial pressure of water vapor under the same conditions measured in millimeters of the mercury pillar (p, mm.rt.st.). Therefore, to determine moisture content in the air in the air temperature to find partial pressure saturated vapor (see Alp., Table 2.7) and multiply this value to the relative humidity of the air in the fractions of the unit.
When admitting inside the insulation (q kj / h) from heated equipment and products, the normative air volume for their removal is calculated by the formula:
L UD \u003d Q / [C × R CP × (T 1 - T 2)], (2.13)
where the heat capacity of the air, C \u003d 1.2 kJ / (kg × hail);
r cp - air density with average temperature air (t cf), kg / m 3;
t 1, T 2 - temperature of respectively removed and supply air, o C.
t cf \u003d (T RZ + T 1) / 2, (2.14)
where T RZ - the temperature of the air in the work area, for which the highest value is accepted permissible temperature For the work of this category of gravity for the warm period of the year (see Ap., Table 2.3).
t 1 \u003d T RZ + DT H × (H-2), (2.15)
where DT H is a temperature gradient, taking into account the increase in temperature at the height of the room, DT H \u003d 0.5-1.5 o C / m;
H is the height of the room, m.
Air density (R T) at a temperature (t) of more than 0 o C can be calculated by the formula:
r T \u003d 1.29 ×. (2.16)
If there is no technological equipment in the room, the source of revenues of toxic substances, dust, heat or moisture, but at the same time many people can be, then the necessary air exchange (L UD) is found according to the formula:
L UD \u003d L H × N, (2.17)
where L H-Furious air volume per person under sanitary requirements, m 3 / person × h: If there are natural ventilation for industrial premises - 30, public and administrative - 40; Without natural ventilation for manufacturing, public and administrative - 60.
N-maximum number of people who can at the same time be present in this room, people.
Determination of the effectiveness of natural ventilation - aeration
The removal of insulators from the technological equipment (q) in the "hot" rooms is carried out, most often, due to organized system Natural ventilation- aeration. To carry out aeration on the roof of the building, there are special structures - aeration lights or deflectors through which the heated air is removed from the room due to thermal and windproof.
Evaluation of the effectiveness of aeration is carried out by comparing the real area of \u200b\u200bexhaust holes in the aeration lamp (S p) or the diameter of the deflector (D R) with their regulatory values \u200b\u200b(S H, D H).
The regulatory area of \u200b\u200baeration lamp in m 2 is found according to the formula:
S H \u003d L UD / (3600 × R × W), (2.18)
where L Ud is a connection of the air, which should be removed through an aeration flashlight for an hour by sanitary standards, m 3 / h, (see F-Lo 2.13);
r is a coefficient that takes into account the active area of \u200b\u200baeration lanterns and the receiving values \u200b\u200bfrom 0.16 to 0.65;
w is an average air movement speed in the plane of aeration lamp, m / s.
w \u003d (2h y × g / r) 1/2, (2.19)
where H in the expression at the top of the room, which ensures air removal through an aeration lantern, kgf / m 2;
g - acceleration of gravity, m / s 2;
r - density at the temperature of the air removed, kg / m 3.
With zero air balance (the influx is eclipsed):
H y \u003d \u200b\u200bH t / 2; and H T \u003d H (R n - R y), (2.20)
where n T - thermal pressure, providing air flow and removal using aeration system, kgf / m 2;
h - the distance from the middle of the supply to the middle of the exhaust holes, m. For approximate calculations, H can be taken equal to 1-2 m less than the height of the building;
r n; R y is the density of the appropriate and removed air, kg / m 3.
Air density, taking into account the temperature of the supply and remote air, is calculated by formula 2.16.
In small production buildings The channel aeration is used, at which low-quality air is removed through the ventilation channels provided in the walls of the room. To enhance the drawing from the channels on the roof of the building, deflectors are installed - devices that create cravings both due to thermal pressure and by blowing them by wind. The performance of the deflector is proportional to its diameter (D, M) and can be found by the formula:
D \u003d 0.0188 (L y / w n) 1/2, (2.21)
where L y is the normative volume of air to be removed using this deflector, m 3 / h;
w P - air velocity in the deflector nozzle, m / s. This speed is taken equal to 20 - 40% of the average wind speed for the locality where the room is located. For the Ivanovo region, the average wind speed is 3.5 m / s.
Question from Dmitry:
Hello! Can you please tell me what regulatory requirements for verification and maintenance support and exhaust ventilation and air conditioners in private medical centerWhat supervision follows this (checks)? What is the frequency of such checks and maintenance?
Answer for Dmitry:
Hello Dmitry.
According to clause 3.1.1. GOST 12.4.021-75 SSBT. Ventilation systems. General requirements The operation is allowed ventilation systems that fully passed commissioning and having instructions for use according to GOST 2.601-2006, passports, repair and operation logs. The instructions for the operation of ventilation systems should reflect the questions of the explosion and fire safety. Planning inspections and verification of the compliance of ventilation systems with the requirements of this standard should be carried out in accordance with the schedule approved by the administration of the object (clause 3.1.2. GOST 12.4.021-75). Preventive inspections of ventilating equipment, cleaning devices and other elements of ventilation systems, servicing premises Categories A, B and B should be carried out at least once in shift with the inspection results in the operation log. The faults detected at the same time are subject to immediate elimination (clause 3.1.3 GOST 12.4.021-75). Cleaning ventilation systems should be made in time, installed instructions Operating. The cleaning mark is entered into the system repair and operation log (clause 3.2.7. GOST 12.4.021-75). The form of the journal of repair and operation of the ventilation systems can be found in Appendix 10 of the RD 34.21.527-95 " Typical instruction For the operation of heating and ventilation systems of thermal power plants.
Efficiency of the ventilation system in medical institutions It must be checked once a year.
Justification:
The heating, ventilation and air conditioning systems should provide the normalized parameters of the microclimate and the air of the rooms in which medical activities are carried out. One of the most important elements Any building is a system of supply and exhaust ventilation with mechanical and (or) natural motivation. The mechanical supply-exhaust ventilation system must be sent (clause 6.5 SanPIN 2.1.3.2630-10 "Sanitary and epidemiological requirements for organizations carrying out medical activities") (hereinafter - SanPine 2.1.3.2630-10). Quite often there is a violation associated with the operation of the supply and exhaust ventilation system - not to test the effectiveness of its operation, which does not comply with the requirements of clause 6.5 Sanpin 2.1.3.2630-10. Due to the specified norm, the performance of work should be conducted once a year. maintenance (If necessary), as well as cleaning and disinfection of mechanical supply and exhaust ventilation and air conditioning systems.
In accordance with paragraph 11.2. One hundred nostroy 2.24.2-2011 Network engineering Buildings and structures internal. Ventilation and air conditioning. Testing and adjusting the air conditioning and air conditioning systems »(hereinafter - one hundred nostroy 2.24.2-2011) during the operation of heating and ventilation systems, it is necessary to have:
- Passports of the installed form on thermal nodes, heat consumption systems and ventilation plants with protocols and acts of inspections and repairs;
- working drawings of equipment;
— executive schemes thermal assembly and pipelines with numbering of reinforcement and equipment, armature instrumentation and automation;
- journals of operation of heating and ventilation systems;
- Factory instructions for maintenance of heat consumption and ventilation systems;
— official instructions service personnel.
According to paragraph 11.3. One hundred Nostroy 2.24.2-2011 Factory instructions should contain:
— brief description systems or equipment;
- order of start-up, stop and maintenance during normal operation and measures taken in emergency modes;
- order of admission to inspection, repair and testing of the system or equipment;
- Safety and explosion safety requirements specific to this system or installation.
In the factory instructions for the operation of heating and ventilation systems, specific actions of personnel to eliminate systems faults, taking into account their nature and place of occurrence, the appointment of the served room, the degree of influence of malfunction on the performance of technological equipment and the safety of the service personnel (clause 11.4 hundred Nostroy 2.24 .2-2011).
When conducting planned warning repairs, the following documentation should be drawn up (p. 11.5 hundred Nostroy 2.24.2-2011):
- annual and monthly plans for repairing heating and ventilation systems;
- Vedomosti Defects and Works, Estimation (if necessary);
- schedule and project of repair organization;
- necessary repair documentation;
- when carrying out work on reconstruction or modernization
- Approved technical documentation.
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