Ventilation requirements for production facilities. Ventilation of industrial premises: rules for air exchange. Design and installation

As applied to the industry, ventilation of industrial premises is a complex of measures, equipment and organization of its maintenance, which aims to maintain stable air exchange and movement of air flows in the premises.

Ventilation systems are installed to maintain regulatory meteorological parameters in rooms of different functionality. Classify types of ventilation production facilities can be based on the following features:

Increased air supply plays an important role in particle control. In turbulent ventilation, the limiting distribution of individual particles from different pollutants is critical for the degree of purity. The use of high-efficiency filters ensures the removal of very small particles. Preserving excess pressure is to prevent dust from entering clean rooms from surrounding areas. For ventilation turbulent rooms, the ventilation grill plays an important role.

In these rooms, gratings for wall suction are widely used. It is advisable to place them evenly around the perimeter of the room. That's why they are not recommended to place the equipment near the walls. It is desirable that they are at some distance from them. The recommended air traffic management structure is usually "rough".

The method of air exchange is natural and forced ventilation.
Purpose: supply or exhaust ventilation.
Service area: common or local system.
Structurally: channel or non-channel ventilation system.

The basic stages of design of industrial ventilation

Laminar air flow The organization of ventilation with laminar airflow is usually carried out when low concentrations of pollutant particles are required. In this case, turbulent flow does not pass through the room at first, where the current lines are approximately parallel, and throughout the space of the restricted space the velocity fields are even and approximately the same. The degree of purity is determined by the speed of pollutants emitted to the workplace. The flow velocity is usually chosen to suppress the gravitational jets forming, and the resulting vortices and the developing turbulence do not create any difficulties.

Types of industrial ventilation

Such natural ventilation of industrial premises is based on natural draft of air, the appearance of which is influenced by the following factors:

Difference between outdoor air temperature and indoor temperature (aeration).
The difference in atmospheric pressure between the lower level in the room and the extractor, which is mounted on the roof.
Wind speed and pressure.

The organization of work of natural ventilation of premises does not require significant infusions into the equipment. The installation of natural ventilation is the simplest of existing systems and does not require electricity supply. Disadvantages - the dependence on the values of temperature, pressure, direction and wind speed. The exact calculation of the natural ventilation of industrial premises is carried out according to the formulas:

Exit beyond these limits is allowed only in certain cases, and, according to experts, deviations from the average speed should not exceed ± 20%. It is believed that such an air jet speed can successfully remove relatively large particles before they settle on the surface. Laminar air flow provides immediate removal of pollutants released into the air. On the contrary, the turbulent airflow for removing dirt depends primarily on mixing and diluting the particles.

It is good to bear in mind that in an empty room where there are no obstacles, pollution is removed at air flow rates much lower than indicated. In a real situation, however, there are various obstacles and movement of people on the plane. When colliding with an obstacle, the laminar flow becomes turbulent. In these zones, higher concentrations of contaminants are observed. It is desirable to avoid the formation of overloaded areas, so that furniture and equipment are located so that they do not predispose to their formation.

Effective ventilation and air conditioning of industrial premises is calculated by the multiplicity of air exchange (L, m³ / h):

L = n ˣ S ˣ H

n is the multiple number of air exchange for a particular room. Usually for apartments and houses n = 1, and for warehouses, shopping or production areas n = 2.
S - area, m².
H - height, m.

The ventilation capacity by the number of people in the room (L, m³ / h):

It was found that the cleanliness of rooms with a laminar flow is directly proportional to the flow rate. As a rule, when using laminar air flow, the distribution scheme is designed to supply air from the ceiling and pass through the ventilation holes in the floor. If the room is narrow, air is not diverted through the floor, but through the ventilation suction holes near the floor.

Used air exchange schemes As we have already noted, the type of ventilation is usually chosen depending on the class of cleanliness of the room. Air is fed through the entire section of the ceiling or one of the side walls where absolute filters are installed. The air outlet is on the opposite side.

L = N ˣ Lnorm, where:

N - the nominal number of visitors to the premises.
Lnorm - air flow per person, m³ / h. For one person LNorm = 20-60 m³ / h.

Mechanical air exchange

Mechanical ventilation of industrial premises works with the use of equipment and devices that move air masses over long distances, but at the same time expend a lot of electricity. The advantage of such equipment is that they regulate the number and direction of air flows regardless of the surrounding conditions.

In those cases where the number of technological operations requiring a high-frequency class is limited, experts recommend that processed air be supplied directly to workstations. This results in significant energy savings, as well as reduced vibration and the attainment of an additional noise-absorbing effect.

An efficient solution is also the use of a clean tunnel with a separate charging and maintenance area. Clean cabins and workplaces When there are technological processes in the room that require a higher class of cleanliness than common service throughout the room, the use of clean cabins and workstations is economically profitable. They are usually equipped with a fan that sucks air from the room and pushes it through the absolute filter in the work area.

Also, the air in such systems can be heated, cooled and cleaned. The combination of mechanical and natural systems led to the creation of mixed ventilation. therefore calculation of ventilation production facilities in this case is necessary to create efficient and efficient air purification.

Local ventilation of premises

As is known, the main purpose of ventilation systems is to maintain cleanliness and air mobility in a restaurant within the prescribed limits. In ventilated areas, fresh air must be supplied at a flow rate to meet the fresh air needs of people living in them. At the same time, it is necessary to limit the possibility of accumulation of harmful substances. The correct design and dimensions of the distribution network and air distribution devices are the key factor that determines the effective operation of the system.

Injection of air currents and extraction in the field

The inflow of a fresh jet is provided by forced ventilation. If necessary, the jet of fresh air can be pre-cleaned. Reverse exhaust ventilation of industrial premises is designed to remove the exhaust air. The extractor set includes exhaust fans and ventilation grilles, as well as air ducts for equipping the ventilation ducts.

Providing good ventilation is not only a matter of correct calibration, but also a good air traffic management. It is for this reason that experts in this area recommend that a ventilation system be provided for the design of all other systems and installations in the restaurant. Before determining the air ducts and the location of ventilation grids in a way that does not damage the interior design of the room. And, of course, at the same time ensuring the effective functioning of the system.

It is desirable that the supply of fresh air at each point of the room is carried out at regular intervals and at the same rate. In the premises of visitors it is undesirable to create zones with increased or reduced airspeed. Usually, even air distribution is achieved by appropriate selection and distribution of ventilation grids in the room. It's a good idea that the air ducts are hidden in the surrounding walls or ceiling, so as not to disturb the interior design. It is advisable to pre-treat the air in ventilated rooms.

Exhaust and supply ventilation systems should always work only together, but there are cases when the use of only one system is recommended. Production combined extract and input ventilation production facilities may be local or general exchange. The exact air flow is calculated by the formula Lots = 3600Fwо, where:

For this purpose it is recommended to use filters for different degrees of filtration. In addition, for the ventilation system it is necessary to have a section for preheating the air. To prevent the ingress of any unpleasant odors or harmful substances, the supplied exhaust air should be sucked from places where there are no sources of harm. It is recommended that the site be removed from the roads, as well as from places where household or industrial waste is collected. Of course, a suitable solution is to determine the intake of fresh air from neighboring green areas.

F - total area of openings, m2.
wо is the average air retraction speed, m / s. The speed wo depends on the toxicity of harmful emissions, such as the production operation, and a more accurate calculation of the exhaust ventilation of the production premises is carried out by experiments.

What is an air shower?

The local supply ventilation system is an air oasis and an air shower. The air shower system pushes clean air to the workplace and lowers the temperature in the supply zone. The air oasis is a zone for supplying cold air, alienated by partitions. To the systems of local fresh air ventilation is an air curtain forming an air barrier or changing the direction of air movement. In production, the release of harmful impurities is neutralized by the use of a mixed ventilation system.

The problem of noise ventilation system. The operation of some objects in the ventilation system is accompanied by an increase in the levels of generated noise. This requires taking measures to limit the spread and achieve ventilated premises. If the system has an incorrect size and inaccurately calculates the air speed in the air distribution devices, they can also be a source of noise.

Thermal comfort In the process of designing plants in restaurants, it is necessary to pay due attention to the thermal comfort of people. The ventilation system, together with the air conditioning system and regardless of the season, should provide a suitable indoor climate. Namely, in warmer months they offer coolness, comfort during the transitional seasons, and in the colder months they do not allow creating currents and passing cold airflows through the room. As a good technical solution, integration of ventilation and air-conditioning systems with central airflow control is also adopted.

The regulatory requirements for the ventilation of industrial premises for the local exhaust system are simple - reliable removal of hazardous impurities from the areas of their localization. Local exhaust hoods and removes gases, dust, smoke with special suction.

Local exhaust ventilation is installed to prevent the spread of harmful emissions to production facilities. But it does not solve all the problems - to clean the room of harmful impurities on a large area, local ventilation can not. For this there are general exchange ventilation systems.

Emergency artificial ventilation

Kitchens are the main part of public catering enterprises, which mainly carry out preparatory, finishing and washing operations. During the process, significant amounts of water vapor, oily aerosols, odors and heat are released. For this reason, and to meet the hygiene requirements, the kitchen is necessarily equipped with ventilation suction and suction. Above the heat treatment facilities, it is necessary to place local suction devices to suck off the vapors at a rate that prevents their spreading in the room.

Airflow exchange options

The effective ventilation standards of industrial premises are reflected in SNiP 41-01-2003 of 26.06.2003. According to these regulations, general exchange ventilation must ensure the exchange of air throughout the room. Correctly installed general ventilation of production premises removes waste materials throughout the room, and the supply equipment supplies clean air back.

This creates favorable conditions for the staff and limits the possibility of spreading odors in other premises. If the restaurant or cafe is located under office, residential or other residential space, it is necessary to provide an outlet for suction channels above the roof of the building. For a hot kitchen, the supply air is usually at a lower temperature. A good solution is to supply air through low-speed air distributors in the lower part of the room. Fresh air emits contaminated warm air from the room, leaving no sudden changes in temperature and does not create conditions for the formation of currents.

Supply air exchange of air masses

Assimilation of excess moisture, heat and dilution of harmful emissions and impurities - the tasks of supply ventilation. All this allows you to comply with sanitary and hygienic standards and standards for a comfortable stay in the work area.

Climatic system - technical solutions Various air conditioning systems are used to ensure good air conditioning in public areas. Among the most commonly used technical solutions is a pressure suction ventilation system in combination with a split or split system. In this case, mainly cassette or channel indoor units are used. They are preferable because they are installed in a false ceiling, leaving them hidden and not violating the concept of the interior.

If the room is cold, then the general ventilation ventilation solves the problems of mechanical motivation, cleaning and heating of the air supply air.

Extraction of general exchange type

The simplest device for organizing the general exchange exhaust ventilation system is a fan with an air vent in the windows or in the exhaust channel. If the duct length is more than 30-40 m and the pressure drop is more than 30-40 kg / m 2, the axial fan should be replaced by a central one. General ventilation systems for industrial premises often work in conjunction with other ventilation systems (usually natural or mechanical ventilation), because due to the heterogeneity of harmful impurities and different conditions for their formation, the use of one system is ineffective.

As a rule, they are placed above the central area of the room, which makes it possible to create a uniform temperature field and exclude the possibility of excessive noise. Advantages of the cassette-type separation system are the uniform distribution of the air flow in four directions, which makes it possible to use them in large rooms. Very suitable for rooms of more complex shape. They do not violate the general appearance of the institution, since only the decorative grid is visible. In the case of an air duct type duct system, the distribution of the air flow takes place through a network of channels.

Air ducts for ventilation of premises

The use of ventilation systems implies in some cases for the effective movement of air the presence of a network of ducts, that is, channel systems. In the absence of ventilation ducts, such a system is called non-channel. For example, the fan is installed in the ceiling or in the wall, if available natural ventilation systems etc. Any ventilation system has 4 main properties: functionality, volume of serviced areas, method of moving air masses and design.

The main difference of the type of the channel from other types of split-systems is the possibility of supplying fresh air with a flow that provides the necessary ventilation of the room. Through the air duct system, air is supplied to the premises at the same time by several countries and, if necessary, can be distributed in several rooms. Among the most common models of split systems is the type of wall. The reasons are their low cost, compact size and relatively easy entry into the interior. For large institutions it is recommended to use multi-zone air conditioning systems using the same indoor units as in split systems.

Creating a truly comfortable and cozy atmosphere at the workplace not only increases the productivity and efficiency of the labor process, but is also an indispensable condition that the sanitary authorities put forward. Therefore, ventilation systems are as important in production as the elements of a central heating system or power grid services. The installation of such systems is a rather complicated and time-consuming work, therefore it is usually not done by oneself, but trusted by professionals with solid experience. In any case, to know about the principles of functioning, design and development will not hurt anyone.

Air conditioning and various areas of the premises in production is carried out using sophisticated systems, including in addition to the air duct, also various air heaters, filters, coolers, recuperators, fans and other elements. The ventilation system, regardless of the variety of the production process, the area and size of the workshops and the contamination of the airspace, should perform such functions:

Providing fresh clean air to the workers of the enterprise.
Removal of unpleasant and foreign odors, as well as dust from the room.
An important function of the ventilation system is filtration from various harmful impurities that arise as a result of certain technological influences and conditions.

Inset: Important: Ventilation of mechanical and natural type is used in industrial and production shops for normal air exchange. When designing works, it is necessary to take into account various regulatory documents regulating the condition of factory and factory shops.

During the manufacturing process associated with the manufacture of pharmaceuticals or products from processed oil, toxic elements that represent a certain danger to human health are released, so the ventilation system must ensure their efficient and immediate neutralization.

To develop or in a production room, it is necessary to admit only highly qualified specialists, certified engineers and professionals. At the same time, it is necessary to take into account climatic and weather conditions, the number of workers, the size of the room, the features of production and many other nuances and features.

Elements of any ventilation system are air ducts, exhaust and supply devices, as well as equipment that helps create a comfortable and cozy indoor microclimate (including humidity stabilizers, as well as air-conditioning units and air conditioners).
For normal ventilation of various objects in production conditions, it is necessary to use such equipment that is able to remove from the air particles of dust, aerosol and gas that appear as a result of the operation of complex equipment.
In some industries (such as pharmaceutical or high-precision electronics), specific working conditions are required, therefore, various additional elements, such as special filters and high-power air conditioners, are added to the powerful ventilation system.
According to the operating instructions for certain types of equipment, those workshops and areas where evaporation that is hazardous to human health may be present should be additionally equipped with trap-extractors, which are separated from the general workshop network.
Devices that carry out hygienic-sanitary control of ventilation systems are part of air exchange systems, and depending on their indications, special equipment that removes various toxic impurities and purifies air can be connected.
During the design of ventilation systems, it is necessary to take into account such a parameter as the cost of operation. It is best if the hot air that leaves the room is used in special exchangers, and cold air is used to cool the machines and other equipment.

Table: Heat consumption of the ventilation system

Ventilation, which is used in industry, is divided into the following varieties:

Ventilation of the general exchange type is responsible for the normal replacement of air masses in the room. The most typical example is an ordinary fan of an axial sample, which is inserted into a wall or window channel. Based on such parameters as the length of the duct and the cross section, the corresponding capacity of the equipment is selected.
(or individual type) - allows you to clean the air of various toxic impurities, smoke, heavy dust and other substances that can harm human health, directly in the workplace.
Emergency air purification from gas, smoke or all kinds of toxic impurities is resorted exclusively to force majeure cases, therefore the standards here are different from those generally accepted in the industry and will not be considered in this context.

Ventilation is also mechanical and natural. The natural scheme removes and influxes the air masses through a thrust that arises because of the difference in temperature and pressure inside and outside the production room. The effective functioning of such a ventilation system is influenced by:

The difference in the temperature of the ambient air inside the production hall and on the street.
The difference in atmospheric pressure near the exhaust outlet of the extractor and near the floor in the room.
The speed of movement of air masses in the street.

Types of ventilation system

The natural system of ventilation and airing is distinguished by its noiselessness, ecological compatibility and economy. However, changing weather conditions can negatively affect its effectiveness. A similar disadvantage is lacking mechanical ventilation, which is able to move the air flow through the duct of any configuration and cross-section to any distance. In such cases, often installing additional equipment that heats the air, and also moisturizes, dries or filters it if necessary. To date, the most popular combined ventilation systems, which use elements of both mechanical and natural systems.

To realize normal natural ventilation, there is no need to spend significant funds, conduct electricity, or buy additional equipment. Turning to professionals who make exact calculations and plans for optimal ventilation in a particular industrial or industrial room, you can solve the problem of ventilation and compensate for such a disadvantage as the dependence on speed and wind speed changes, pressure and temperature.

For the mechanical ventilation of industrial and industrial premises requires a fair amount of electrical energy, so this method is not always economically viable. The advantage of this method of ventilation is the independence of airflow and temperature from environmental conditions. Air in such systems is often heated, and also cleaned or cooled if necessary. To date, the most popular is the combined ventilation system, which combines elements of mechanical and natural ways of airing the room.

To the standards of ventilation include certain provisions, according to which the ventilation system must be absolutely in all production halls and premises. And regardless of the functional characteristics of the occupied area and the number of employees on it. The capacity of the ventilation equipment should be sufficient for the fastest possible cleaning of the air in the room in case of emission of harmful substances or smoke. Develop a project, which will further implement the work of the ventilation system, should professionals who are able to do this in full compliance with applicable laws, documents and regulations. During design, you should take into account such parameters:

inside the workshop or production room.
Conditions of fire safety.
Indicators of air humidity.
The presence and number of toxic and toxic substances that pollute the environment.
Climatic features.
Area and functionality.

It is worth noting that the provision of air for each employee is the norm, which is monitored by various agencies and services. The norm is equal to thirty cubic meters per hour on an area less than or equal to forty square meters. For large production complexes, such norms are calculated in a separate order. When calculating the technical characteristics of the ventilation system, it is worth taking into account such nuances:

The ventilation system should not be a source of noise, which is very prominent even during the operation of process equipment and machines. The noise level should be at an average or low level, otherwise a long stay in the shop will become problematic.
In the event that the ventilation system has been installed for a long time and has not been thoroughly cleaned for a long period of time, it is most likely that it itself is the cause of increased pollution of the surrounding airspace. To ensure that the ventilation system is not a source of pollution, it is recommended to clean it at least several times a year.

The tasks of the ventilation system of the supply air type include compliance with sanitary and hygienic standards due to the assimilation of excessive moisture, dilution of toxic emissions that can damage the human body and reduce the concentration of harmful impurities. All this allows the employee to be on his own site in a comfortable environment that meets all established norms and rules. In the event that there is a low temperature in the room, the ventilation system of the supply air type can solve this problem by heating the supply air masses.

The simplest device, which is installed in various workshops and production facilities, is a fan that has an air vent. Due to the fact that the number of various harmful and toxic impurities in enterprises is usually higher than normal, the use of only one ventilation system is not always effective. To maximize the safety of employees, modern enterprises use both a natural and a mechanical system.

In the modern market, a huge number of different systems, ventilation, which allow you to create within the workplace the most safe and comfortable working conditions. The widest choice of devices that differ from each other both in functionality and price, will satisfy the demands of even the most demanding customer. During the construction of a complex industrial ventilation system, it is necessary to install both a supply equipment that is a guarantee of supplying clean air to the shop and plant premises and special extraction systems. With their help, you can remove air from the workplace, saturated with pathogenic bacteria, toxic substances, dust, smoke and other harmful elements. It is selected proceeding from features of manufacture.

Choose one or another variation of the equipment individually, with due regard for the differences and features that are inherent in a particular industrial or construction large object.

The ventilation system must have the following parameters:

Economical.
Efficiency.
Reliability.
Quick payback.

Thanks to clean and cool air, you can achieve not only good mood, health and efficiency of employees, but also low wear of technological equipment and various tools. It is economically expedient to add a device in the design of the project, which is connected to the ventilation system and provides a comfortable indoor microclimate.

To date, the most optimal way to control the parameters of the ventilation system is the use of automatic computerized systems that make changes to certain characteristics, based on data obtained from outdoor sensors. Thus, it turns out to achieve maximum economy and efficiency in work.

Thanks to the use of a supply or exhaust system, it is possible to easily adjust the humidity indices at the plant to normal, and also to neutralize, heat, cool, filter or humidify the air. The huge advantage of forced ventilation is that its operation is not affected by external conditions and weather factors. Removal and air supply can be made from the required point. You can make exact calculations of supply or exhaust ventilation and make a schedule of costs.

The work of ventilation systems is influenced not only by competent selection of equipment and installation, but also by atmospheric discharges, the shape of air receivers, the correct installation of filters, fans, air ducts and other elements. At the enterprises it is most expedient to install axial or radial blowers operating from electricity. Thanks to such a solution it is possible to easily provide employees with clean airspace at the workplace, free of harmful impurities and toxic elements. For the best filtration, electrofilters and other components are often used today, which can safely protect even the environment saturated with aggressive chemical compounds and components.

Air conditioning in enterprises and industries allows to achieve a normal microclimate, which is especially important for the optical industry, instrumentation, the vacuum industry and other areas where maintaining a certain humidity in the room is very important. To configure and install the ventilation system, it is best to refer to professionals with experience and knowledge in their field.

Ready-made ventilation systems need periodic cleaning, since if the channels are clogged, being in the production hall or room becomes unsafe because of the high concentration of particles of dust and harmful elements. For maximum efficiency, different filters are used today, made of felt, fabric, porcelain rings and all kinds of porous materials that perfectly absorb dust and toxic substances that can damage human health.

Features of equipment mounting

During the installation of ventilation systems in factories and industrial facilities, it is necessary to take into account a huge number of features and nuances that directly affect the durability of the design and the efficiency directly during operation. That is why it is necessary to attract highly qualified specialists for installation of separate elements of the air exchange network, which have the relevant knowledge and experience. It is also important to choose the right place for installing equipment, such as filtration systems, fan units, heat exchangers and other units.

In industrial and production rooms are usually attached directly to the ceiling. If desired, they can be hidden using hanging decorative panels. In those rooms that are used for commercial purposes, it makes sense to use channels made of plastic or copper, which are reliable and durable and have an attractive appearance.

Currently in the construction of such types of air channels:

Tough. For their production, materials such as fiberglass, multi-layer aluminum, galvanizing and others are used. Of these elements, the installation of virtually the entire ventilation system is carried out. The only exception is the special parts of the shaped sample, which are used for the device of branching, contours and turns. To transport air, which contains various harmful impurities, it is worthwhile to use air ducts with walls of increased thickness.
Flexible. Their main purpose is the communication of various sections and openings with the ducts of the main line. For the design of a local ventilation system, the purpose of which is air cleaning in the immediate vicinity of the workplace, aluminum hoses are often used.

Installation of ventilation ducts in industrial and industrial areas is carried out in the following order:

To begin with, the wall thickness and air channel cross-sections are calculated, and then the mass of each of the elements of the ventilation system is calculated based on the obtained data. Sometimes the installation of channels with a square cross section is impossible because of insufficient space. Therefore, faced with a similar situation, it is worth using rectangular air ducts to solve the problem.
Then, at the junction points, the fixing points of the air ducts should be indicated. Thanks to this, you can easily calculate the required number of fasteners, brackets and other accessories. It should be remembered that for mounting brackets it is undesirable to allow the occurrence of oscillations of long network segments directly during the passage of air through them. It is most preferable to equip the structure with an excessive number of fasteners, since in this case they will withstand even an increased load without problems.
When the installation of the trunk channels is carried out, it is possible to start installing separate suction and spray devices. For such cases it is recommended to use special hoses that have the flexibility and the required cross-section.

conclusions

Installation and design of industrial ventilation systems is a responsible and complex process. The finished project must comply with strict building codes and current regulations. This directly affects the health of employees and the efficiency of the whole team.

Ventilation requirements for production facilities. Ventilation of industrial premises: rules for air exchange. Design and installation

The basic stages of design of industrial ventilation

Types of industrial ventilation