Types and features of industrial ventilation systems. Ventilation of industrial premises: rules for organizing air exchange Exhaust ventilation system in production

With regard to industry, ventilation of industrial premises is a set of measures, equipment and organization of its maintenance, pursuing the goal of maintaining stable air exchange and moving air flows in the premises.

Ventilation systems are installed to maintain standard meteorological parameters in rooms of different functionality. The types of ventilation of industrial premises can be classified according to the following criteria:

The way of organizing air exchange is natural and forced (mechanical) ventilation.
Purpose: supply or exhaust ventilation.
Service area: general exchange or local system.
Structurally: channel or channelless ventilation system.

Types of industrial ventilation

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

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

The organization of the work of natural ventilation of the premises will not require significant injections into the equipment. Installing natural ventilation is the easiest of all. existing systems and does not require electricity. Disadvantages - dependence on temperature, pressure, wind direction and speed. The exact calculation of the natural ventilation of industrial premises is carried out according to the formulas:

Air flow exchange options

The current ventilation standards for industrial premises are reflected in SNiP 41-01-2003 dated 06/26/2003. According to these regulations, general ventilation must ensure the exchange of air throughout the room. Properly installed general ventilation of industrial premises removes waste masses throughout the entire volume of the premises, and the supply equipment supplies clean air back.

Supply exchange of air masses

Assimilation excess moisture, heat and dilution of harmful emissions and impurities are the tasks of supply general ventilation. All this allows you to comply with sanitary and hygienic norms and standards for a comfortable stay at the work site.

If the room is cold, then the supply general ventilation also solves the problems of mechanical stimulation, purification and heating of the supply air masses.

Hood of general exchange type

The simplest device for organizing a general exhaust ventilation system is a fan with an air vent through windows or into an exhaust duct. If the air duct is longer than 30-40 m and the pressure drops more than 30-40 kg/m2, the axial fan should be replaced with a central one. General exchange ventilation systems of industrial premises are often paired with other ventilation systems (more often it is natural or mechanical ventilation), since due to the heterogeneity harmful impurities And different conditions their formation, the use of any one system is ineffective.

Air ducts for ventilation of premises

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

Industrial ventilation is a set of measures aimed at organizing and maintaining stable air exchange in industrial premises. Operating equipment and production processes are often a source of airborne particles and toxic fumes, which can adversely affect human health. In addition, the lack of fresh air reduces productivity and the ability to tolerate physical exercise.

The task of ventilation of industrial premises is to remove exhaust air (exhaust ventilation system) and replace it with fresh air (supply ventilation system), specially cleaned, heated or cooled, that meets all standards.

When designing ventilation, the following conditions must be taken into account:

the presence of harmful fumes
change temperature regime
increased gas content

Solution

It must be said right away that everything depends on the type of production, therefore, when choosing a ventilation system, you need to build on:

Technique, production parameters
Required working conditions

Most often for ventilation of large production (120 thousand cubic meters) is usedsupply and exhaust ventilation with cooling or heating water. While not all production facilities are suitable for a system with heat recovery.

Ventilation price (online calculation)

Room/building type:

Select type Office or administration building Cottage Apartment Commercial premises (shop, shopping center) Sanatorium, hotel Gym, fitness center Warehouse Industrial, industrial premises Cafe, restaurant Swimming pool Server room

Equipment class:

Economy Medium Premium

The total area of all serviced premises:

m 2

Average floor height:

Maximum (estimated) number of people in the room/building:

people

Show cost

Air exchange rate

The optimal air exchange rate in industrial premises is determined based on the reference tables of SNiP 2.04.05-91 and is in a fairly wide range: from 3 to 40 times per hour. This means that in one hour the air in the room must be completely replaced with fresh air a given number of times. Also, the norms establish the minimum allowable volume of incoming fresh air. Let us consider in more detail what factors influence these calculations.

Factors that determine proper air exchange in industrial premises:

Workshop volume and geometry. Both the total volume of the room and its shape play a role. The fact is that the parameters of the movement of air flows around the room depend on the shape, turbulences and stagnant zones can occur.
Number of employees working in the workshop. The necessary influx of fresh air is determined based on the level of intensity of physical labor. When performing various manipulations that do not require significant physical effort, an air exchange of 45 cubic meters per hour per employee is sufficient, and when performing heavy physical work - at least 60 cubic meters per hour.
The nature of technological processes and air pollution with harmful substances And. For each substance there is a maximum permissible concentration, based on which the intensity of air exchange is determined, which will allow maintaining the concentration within safe limits. The most demanding in terms of multiplicity are dye shops, as well as various industrial sites where volatile and toxic substances are used. In such buildings, the required air exchange can reach 40 times per hour or more.
The heat generated by the equipment. Excess heat energy must also be effectively removed by the ventilation system, especially if the room is not provided with air conditioning.
Excess moisture. If processes involve the use of open liquids that evaporate and increase humidity, sufficient exchange must be provided to maintain stable humidity.

In production workshops with an area of more than 50 m2 for each employee, it is necessary to maintain the calculated air temperature in the permanent working area and at least 10 ° C at temporary workplaces;

In cases where the supply ventilation of the production premises cannot maintain the required microclimate indicators in the personnel service area for economic or production reasons, permanent workplaces are equipped with outdoor air showering devices or a local air conditioning system;

Air temperature working area at industrial facilities with fully automated production lines operating without attendants, it is allowed: in summer, at the level of outdoor air temperature, with excess heat - 4 ° C higher than outdoor air temperature; in winter - in the absence of excess heat - 10 ° C, in the presence of excess heat - an economically justified level.

Industrial ventilation requirements

Ventilation and air conditioning of industrial premises is regulated general requirements SanPiN, as well as parameters that are specific to the given workshop of the enterprise. These include:

mechanical ventilation of industrial premises must comply with fire safety rules;
removal of substances hazardous to health, emissions without access to the work area of personnel;
obligatory hygienic and fire safety certificate of the materials from which the elements of the ventilation system are made;
anti-corrosion coating of air ducts, or they must be made of materials resistant to such influences;
the thickness of the coating of ventilation ducts with combustible paint should not exceed 0.2 mm;
for personnel working areas located directly inside the workshop, concentration harmful substances should not be more than 30%;
humidity, speed indicators of air flow are not standardized in the summer;
in winter period the temperature indicator of the air inside the workshop with the personnel located there - at least 10⁰ С, in the absence of people - at least 5⁰ С;
in summer, the temperature indicators of the internal and external air flows are equal, or the internal temperature does not exceed the external temperature by more than 4⁰ С;
the requirements for industrial ventilation that are not used in the summer of the workshop are not regulated by the temperature indicator;
the total noise level inside the industrial hall should not exceed 110 dBa, this includes the operating noise of the ventilation system.

The above list is quite general. In practice, the requirements for ventilation of industrial premises are supplemented by individual parameters of production, the design of the workshop, the specifics of products, etc. In addition, it is imperative to take into account how heating and ventilation interact inside the workshop. And it should also be taken into account that lighting and ventilation of industrial premises are also interconnected.

Types of industrial ventilation

The classification of industrial ventilation is carried out according to the criteria of localization, direction and mode of operation. Let's consider in more detail.

According to the principle of operation

Natural. It is based on the natural circulation of air flows with different temperatures, pressures, and densities. A heavy cold air stream displaces a lighter and warmer one. IN industrial premises this process can occur through natural gaps, leaks in window doorways, or organized supply and exhaust openings, closed with gratings, deflectors.
Depends on atmospheric conditions, strength and direction of the wind, season (in winter, ventilation is better due to strong draft). This method is not suitable for all industries, especially where there are harmful emissions from operating equipment. It can be installed, for example, in agricultural premises.

artificial ventilation. If production involves side effect in the form of toxic heat and gas emissions, mechanical ventilation of industrial premises is strictly required. The main function is to divert the exhaust air flow from the working area of the personnel, prevent the penetration of harmful vapors into other rooms, compartments, as well as supply fresh outdoor air (purified or unpurified) by the general flow or by address.
It is organized with the help of mechanical means of supply and removal of air masses (supply, exhaust fans, roof installations). It is a more efficient way of cleaning, circulating the air flow inside the industrial workshop.

According to the principle of localization

General exchange. It is designed for uniform cleaning of the entire workshop from harmful technological heat emissions, normalizing the temperature and humidity index, air speed. Quickly copes with a small percentage of air pollution.
local ventilation. It is used when there is a localization of a large amount of toxins, vapors, smoke, etc. in a certain place. It is installed directly above the source of increased heat and gas emission. Hoods or a flexible duct connected directly to the equipment may be used. It is used in conjunction with the general ventilation system as an additional air-purifying equipment.
emergency. Installed and used in the future in case of emergency, for example, fire, excessive release of toxic substances industrial equipment, high level of smoke, etc.

According to the principle of flow direction

Supply ventilation units. The principle of operation is based on the displacement of warm exhaust air by a cold influx through organized exhaust openings at the top of the workshop. They can be both natural organization and mechanical.
Settings exhaust ventilation remove the exhaust air flow along with particles of burning, smoke, toxic fumes, excess heat, etc. Structurally, they can be general or local, most often with forced induction, since it is quite problematic to remove polluted air naturally.
Air handling unit is used most often, provides the necessary circulation of air masses inside the industrial workshop. Most often with mechanical equipment (supply, exhaust fans).

Equipment for ventilation of industrial premises

The forced ventilation system consists of the following elements:

air ducts;
fan;
air filters;
air valves;
air intake grilles;
noise-absorbing insulation;
air heater (air heating);
automatic control unit if necessary.

The mechanical exhaust ventilation device is organized according to the same model, with the exception of the air heater, filters, which are not needed for the exhaust air.

Local exhaust ventilation of industrial premises is organized by exhaust hoods, flexible air ducts connected to a common air exchange system.

In addition, supply and exhaust ventilation can be equipped with a heat recuperator to save energy during the heating of the incoming flow. The supply masses are heated by the heat of the exhaust air, without mixing with it.

Design and installation

To ensure the highest quality ventilation, it is necessary to carry out its design and installation already at the construction stage. This is the only way to take into account all safety measures, to properly design exhaust zones.

But it also happens that it is necessary to install a ventilation system in an already built building. In this case, all the conditions in which the system will be operated, as well as the purpose of the room itself, should be taken into account. The choice of equipment always depends on the explosion and fire hazard of the room.

As is known, general exchange and local ventilation is used for industrial premises. The first is responsible for air exchange and air purification of the entire room. But with the help of local suctions, it is possible to solve only local problems at the place of formation of those very harmful substances. But it is not possible to keep and neutralize such air flows completely, preventing their spread throughout the room. Here additional elements are needed, such as umbrellas.

The choice of equipment for the installation of ventilation of industrial premises is influenced by the type of production and the amount of harmful substances emitted, the parameters of the premises itself, and the design temperature for the cold and warm seasons.

Summing up, I would like to say that such not an easy task, as the calculation, design and subsequent installation of ventilation, must be performed by qualified specialists who have a wealth of knowledge and years of experience behind them.

Ventilation systems management

Automation control of ventilation systems allows you to optimize the process and reduce operating costs. This approach allows minimizing human participation in management and reducing the risk of the "human factor". Automatic control involves the installation of sensors that record the temperature / humidity of the air, the concentration of harmful substances, the degree of smoke or gas contamination. All sensors are connected to the control unit, which, thanks to the specified settings, turns the equipment on or off. Thus, automation helps to comply with the requirements of sanitary standards, quickly respond to emergencies and save significant money.

Ventilation systems are one of the main consumers of electrical and thermal energy, so the introduction of energy saving measures allows to reduce the cost of products. The most effective measures include the use air recovery systems, air recirculation and electric / motors with no "dead zones".

The principle of recuperation is based on the transfer of heat from the displaced air to a heat exchanger, which reduces heating costs. The most widespread recuperators are plate and rotary type, as well as installations with an intermediate coolant. The efficiency of this equipment reaches 60-85%.

The principle of recirculation is based on the reuse of air after it has been filtered. At the same time, part of the air from the outside is mixed in with it. This technology is used during the cold season in order to save heating costs. It is not used in hazardous industries, in the air environment of which there may be harmful substances of hazard classes 1, 2 and 3, pathogens, unpleasant odors, and where there is a high probability of emergency situations associated with a sharp increase in the concentration of flammable and explosive substances in the air. .

Given that most electric motors have a so-called "dead zone", their correct selection allows you to save energy. As a rule, "dead zones" appear during start-up, when the fan is running in idle mode, or when the mains resistance is much less than what is required for its correct operation. In order to avoid this phenomenon, motors with the possibility of smooth speed control and with no starting currents are used, which saves energy at start-up and during operation.

Air exchange calculation example

All living things in nature, one way or another, depend on clean fresh air, and the human body is designed in such a way that it needs oxygen saturation every second. This is especially noticeable when a person endures physical activity, for example, when performing any work.

The supply of fresh air is especially important if workplace located in the production hall. The equipment located in it and the technological processes associated with it are often the main source of various toxic fumes, gases, dirt, dust, and chemical impurities entering the air. Therefore, ventilation in production is an essential measure in the organization of any technological process.

It is an erroneous opinion that the creation of ventilation in industrial premises (workshops, sections) is practically no different from the organization of the air conditioning process, for example, in an office or residential building. In this case, it is worth emphasizing that industrial ventilation is not a one-time measure, but a whole range of engineering developments.

Ventilation in production plays a much deeper role than ventilation (air conditioning) in any other room. It is industrial ventilation that is designed to ensure uninterrupted air purification from various impurities, its functional circulation, while not disturbing the course of technological processes, but creating favorable conditions for their successful implementation.

Ventilation as an engineering and technological complex is divided into two main types:

local;
general exchange.

The main purpose of local ventilation is the localization and subsequent removal of harmful substances directly at the very place of their initial formation. As a rule, a malicious source is covered from all sides by so-called shields that form a cap. Inside this shelter, the pressure is much less than atmospheric pressure, due to which a vacuum is created when air is sucked out (harmful impurities do not enter the surrounding room). Local type ventilation is very effective and, at the same time, its organization does not require huge financial investments, since the removal of pollutants from the air is achieved at a low consumption.

In cases where malicious sources cannot be localized in full, the general exchange type of ventilation is used. From the name it becomes clear that its purpose is a comprehensive air purification in all industrial premises, and it is carried out by diluting the total content of impurities, dirt, dust, as well as moisture and heat.

Classification of industrial ventilation by mode of action

According to the method of exposure, there are the following types of ventilation:

supply air ventilation;
exhaust ventilation;
supply and exhaust ventilation.

Supply ventilation in production is designed to ensure the free supply of fresh air in volumes sufficient for the intended functioning of production. As a rule, duct fans are widely used in supply-type systems. They are able to fully ensure the forced flow of air into the workshop. At the same time, the air pressure increases several times compared to atmospheric pressure and, accordingly, there is an unorganized, natural extrusion of polluted air through various outlets, slots and openings into the street or into neighboring rooms.

Exhaust ventilation in production is designed to remove exhaust air (polluted, either humid or hot), while portions of fresh air enter the premises in an unorganized manner, through doors, windows, wall openings, etc. This type of ventilation is especially effective in industries whose technological processes involve the release of a sufficient amount of harmful substances, moisture, heat, as well as the presence of a large crowd of people.

The simplest exhaust type installation consists of an electric motor and a fan. If you need to purify the air in rooms of a large area or complex layout, then the minimum set is added with special filters and an extensive duct system for extracting exhaust air to the street.

Supply and exhaust ventilation in the workplace provides both the supply of fresh air into the room and the simultaneous removal of exhaust air from it. The distribution of air flows can be carried out in two ways:

mixing;
displacement.

In the first case, high-velocity diffusers are mounted on the ceiling or wall areas of the production workshop or site, through which street air is forced to enter. When it enters a closed room, it naturally mixes with the spent one and, already mixed (with impurities), is removed through special diffusion valves.

In the second case, several low-velocity air distributors are mounted in the lower part of the room (usually on the floor surface), which provide forced supply of fresh air. Since the air distributor is at the bottom, accordingly, fresh (cooled) air is distributed in the lower part of the room, and, following the law of physics, warm air rises and is removed through ventilation holes naturally.

Organization of natural ventilation

Natural ventilation in production is organized on the principle of a self-arising difference in the pressure of air flows, their direction and differences in temperature characteristics. An example of a primitive ventilation of a natural type is the simplest draft, for which you just need to open the doors and windows in the production room. This method of ventilation is also called unorganized, since everything is built on elementary physical phenomena.

An organized method of natural ventilation involves the use of special boxes with dampers, with which you can adjust the strength and degree of natural air flow.

The main advantage of natural ventilation is the low cost of its organization. The creation of such a ventilation method does not involve the purchase of special filters, fans, air exchangers, diffusers and other devices. A significant drawback is the impossibility of complete control over air flows, as well as the low degree of renewal of air masses.

Ventilation of welding production workplaces

Ventilation in welding production is designed to clean the air masses of harmful impurities with high quality and thoroughness, since welding work is one of the most harmful types of work for human health, nitrogen, carbon, fluorine oxides and many other various chemical compounds are certainly formed during the welding process.

The type and organizational type of ventilation of such a workshop depends, first of all, on the dimensions and capacity of the production of welded products.

If the capacity of the welding shop is small, and the volume of products produced is also small, then local ventilation can be arranged at the welding workplace.

If technological processes involve constant local movement of workers throughout the workshop area, then the organization of mobile posts with local ventilation loses its relevance. In this case, it is advisable to organize ventilation of a general exchange type. As a rule, such an extract affects the lower and upper parts of the room, and forced flows additionally provide heating of the room, which is especially important for welding in the cold season.

Industrial ventilation has long ceased to be a simple production necessity. in various industries modern trends(capacities and volumes), ventilation began to act as the most important engineering complex, because the correct organization and subsequent implementation of measures to equip production with ventilation systems contributes to the creation of a healthy microclimate in workshops and production sites. This means that it makes it possible to carry out high-quality technological processes, aimed at observing the basic provisions on safety, and also contributes to the proper organization of each workplace, and most importantly, eliminates harm to the health of an employee involved in production.

Thousands of workers annually suffer from occupational diseases, the main cause of which are harmful substances that appear during the production cycle. The impact of high temperatures, dust, various pollution, "accompany" workers in the metallurgical, chemical, mining industries, and more than a dozen industries.

In most modern industrial enterprises, where a significant amount of pollution is released during the production process, along with a general ventilation system, a local type of ventilation is also used. This type of ventilation system helps to reduce the presence of hazards, gases and dust content, at the place of their production below the WPC, and is appropriate as the main means of their localization.

Types and purpose

Local ventilation can be of two types. Supply - serves to supply air to the devices intended for this: and air showers. These devices, in most enterprises, are used to create "islands" clean air in workshops with a high emission of pollution. Thermal curtains are used to create an air barrier to cold or polluted air masses when there is a need to open doors frequently. The most widespread in hazardous industries is local exhaust ventilation, designed for local removal of polluted air, in places of its occurrence, in a certain production process. The local exhaust ventilation system prevents the spread of harmful substances throughout the production site. The most demanded equipment for exhaust ventilation, at most enterprises, has become local suction.

Requirements for local suction

The main requirement for local exhaust ventilation systems and suction systems is to prevent the ingress of polluted air into the human respiratory organs and eyes. Besides:

They must be simple in design so that personnel can easily assemble and dismantle cleaning devices.
A device for removing harmful substances should not be bulky and bulky, as well as interfere with the production process.
Pollution and gases that appear during the production process must be removed: volatile substances, vapors - up, and dust, and pollution heavier than air - down.

The main types of air intake equipment used in production

Local suction is a part of any modern enterprise. To date, there are several types of these devices:

Semi-open suction. These are mainly ventilated chambers and fume hoods. These devices provide the highest quality removal of contaminants, while minimum flow air. They are of several types. Devices with a top exhaust are used for the release of substances with high temperature or humidity. Cabinets with a lower intake are designed to eliminate “heavy” polluted air. Portable cabinets with side intake of polluted air are used in the elimination of dusty pollution.

A fully open polluted air suction device is an exhaust structure that is located outside the source of their emission. To date, the most popular devices of this type are hoods, suction panels and side suctions. The side air intake is mounted if the source of pollution release requires access from different sides. Exhaust hoods are the simplest version of suction. They are mounted in places where harmful substances are released, which tend to rise up. The umbrella is placed at a height of 1.5 m from the floor. The efficiency of devices of this type is achieved by a large volume of exhaust air.
A completely closed air intake is a part of the equipment and is made in the form of a cover, through the technological openings of which air flows into the device.

Suctions are classified according to the shape of the opening of this device, which are round, square or made in the form of a slot. Round and square holes are most often used in the processes of welding and soldering metals. Ventilation during welding cannot always neutralize all harmful air flows, therefore, in the welding shop in without fail a forced general ventilation system is arranged, with an influx of fresh air of at least 40 cubic meters per hour, per worker. http://www.youtube.com/watch?v=rDK-xg-Cp_A

Features of the ventilation system of the welding shop

There are many types and methods of welding. It was their diversity that led to the variety of suction options used specifically in welding shops. By design features they can be divided into 4 main groups:

Small-sized devices for automatic and semi-automatic equipment. Such ventilation devices are integrated into the welding equipment. These include air intakes in welding holders.
Local suctions built into the welding tables. These devices are used in welding and soldering small parts. Local ventilation for soldering and welding can be connected to the general ventilation system.
Suction units integrated into welding stands and equipment for welding large parts. This group of devices is integrated into welding and assembly installations and stands.
Swivel-lift and portable decontamination devices used for welding operations in various locations. This group of devices includes all portable air receivers of various designs.

The efficiency of air intakes to remove harmful substances requires an accurate calculation of local exhaust ventilation.

Factors affecting the calculation of ventilation of welding production

Advice:
The development of a project and calculations of a ventilation system at any production site is a complex and responsible process that should only be handled by professionals.

This publication will give general information about what affects the calculation of ventilation of a production site with a stationary welding post.

The main factors influencing the calculation of the ventilation system and, accordingly, the selection necessary equipment, are:

Required air consumption by the air intake, depending on its design and type of welding.
Its effectiveness, in a particular workplace.

To calculate the air flow, you can use the formula:

L = 3600 * F * Vo

where:

L– air exchange
F is the area of the suction hole
Vo is the speed of air movement in the hole

You can use ready-made standard calculations, depending on the design of the air intake.

For example:

The car service station is equipped with a stationary welding station, where an exhaust panel is used as a local suction. In this case, the required air flow is determined on the basis of: 3300 m3/hour per 1 m2 of the panel area.

The efficiency of the device is calculated by the formula:

E = (Lm — Lpr) / Lm

where

E- device efficiency
Lm- the power that will be required for the intrashop ventilation system, in the absence of a local air intake
Lpr- air flow required to dilute non-localized contaminants to MPC.

Important!
The efficiency of these devices is not the same for various contaminants released during welding and other production cycles.

An optimal microclimate must be maintained in production. Ventilation design begins with taking into account the characteristics of the industry. Ventilation of industrial premises should promptly remove all contaminants and vapors without overdrying or overmoistening the air.

Ventilation of production facilities is subjected to increased loads

Varieties of systems

Ventilation systems for industrial premises are divided into 2 types:

natural;
automatic.

Ventilation in production, depending on the type of air flow supply, can be supply or exhaust.

natural

The natural ventilation system in the workplace works due to the temperature difference between indoors and outdoors. Wind speed and thermal pressure are the main driving factors of the system. With a sharp temperature drop, warm vapors from the production room are replaced by cooler ones. The operation of a natural ventilation system is based on simple physical phenomena. The higher the ceilings and the greater the air pressure drop at the floor in the production hall, the better the ventilation will be. If there are gaps in the walls and window openings, as well as with frequent opening of windows and doors, there is a high probability of drafts and freezing of the room in winter. In the summer, in areas remote from doors and windows, ventilation standards will be violated.

Aeration is a kind of natural type of industrial ventilation. To implement control, aeration systems are installed. Often, when designing a building, the presence of ventilation systems is not taken into account. In this case, ventilation equipment can be installed in the finished room. Shafts are mounted in the hall of the workshop, which will work by changing the pressure of the air pressure. Mine hatches are covered with deflectors. The wind flow, getting into the deflector, creates a zone of rarefaction of air, increasing the influx of air masses. Such ventilation systems are most often used by agricultural and livestock buildings, forges, and not too large bakeries.

Aeration is the most effective method ventilation production in an elementary way. The supply pipe is fixed at the highest point of the roof.

For large industries need forced ventilation

Automatic

Automatic supply and exhaust ventilation systems make it possible to normalize the microclimate at large enterprises. Such systems have many advantages.

They work regardless of temperature fluctuations in the street.
The supply and exhaust effect can be achieved at any point in the room.
You can change the airflow rate.

It is necessary to comply with the requirements for ventilation of industrial premises. Ventilation equipment of a forced supply and exhaust design allows you to prevent air pollution by chemicals, removing it directly from the source of occurrence. The shape of the receivers, as well as the degree of rarefaction of the atmosphere, affect the quality indicators of work. Ventilation of industrial premises consists of:

air inlet;
fans;
air outlets;
filters;
hoods.

Arrangement of elementary ventilation

In industrial buildings, three-level openings are made with windows of a special shape. The first two levels are localized at a height of 1-4 meters from the floor level. In the roof, protective lights with windows are mounted, in which manual regulation is provided. Air exchange in the summer is carried out by getting air masses inside through the lower vents, and the release of contaminated vapors through the vents in the roof. In winter, air currents pass through the middle row of vents.

The intensity of air exchange is regulated by opening the vents in different positions. In calm weather, the ventilation of the room will be much worse, but with a certain direction and strength of the wind flow, reverse draft may occur. To prevent such an effect, ventilation structures are made protected from the wind by installing special lights.

In the warm season, the cooling of the supply masses occurs due to the spraying of water in the lantern from the nozzles mounted in the transoms. This cools the supply air and increases the humidity.

The ventilation system in the industrial premises is controlled manually. Aeration is not used as ventilation for industrial premises, where a large amount of harmful impurities is expected to spread. The natural air exchange system does not allow filtering the treated air flows.

Types of supply structures

Purpose and classification of air inlets:

closed;
open - the hole for receiving the used air masses is located far from the place of their exit.

An open-type industrial air inlet is a combination of: a casing, an exhaust hood, air vents, and mobile air inlets. According to convection conditions, hot air currents rise up, where exhaust hoods reduce the area of their distribution and produce further removal. The dimensions of the umbrellas must correspond to the area of the hot air outlet. Protective umbrellas can be with or without overhangs.

In galvanic industries, slit-like air extractors are mounted. In workshops with welding machines and blowtorches that operate in a carbon dioxide environment, air inlets are installed directly on the equipment.

If the workplace of a person is not fixed, portable types of ventilation are used, which are attached directly to the welding equipment with suction cups.

The regime type exhaust system is represented by: cabinets, cabins, boxes, cameras. Cabinets are installed in industrial enterprises with abundant release of toxic fumes. The installation of the box is carried out at enterprises with the release of radiation or poisons.

Forced ventilation of the room

Ventilation equipment

Air exchange of supply and exhaust type in autonomous systems is carried out by a fan. The most commonly used models are:

radiator;
axial.

Radiator fans are snail-shaped. When air enters the receiver from the outside, the air mass is redirected and then fed into the air extractor. Depending on the saturation with impurities and the varieties of these impurities, various types of equipment can be used:

standard - recommended for air masses with a temperature of +80, with a low dust content;
anti-corrosion - used to remove alkalis and acids;
spark-proof - used in the production of hazardous explosives;
dust - recommended for installation in a room with an increased dust rate.

Axial fans are blades mounted in a cylindrical housing. The movement of the air flow occurs parallel to the fan axis. The installation of these types of fans is mainly carried out in mines and emergency mines. The advantage is the release of air in several directions at the same time.

Cleaning systems

The quality of the supply air exchange is controlled by the installation of cleaning devices. The air is filtered before being released into the environment. View cleaning systems ventilation will depend entirely on the amount of contaminants in the air stream. The simplest device for a ventilation cleaner is dust collectors. The flow rate in such devices drops sharply, thereby achieving dust settling. The system is suitable for primary cleaning, and with an increase in the amount of dust in excess of the norm, it becomes ineffective.

To capture dust of more than 10 microns, cyclones are installed in production - metal containers, cylindrical shape, narrowed down. A stream of air is supplied from above, due to which dust particles hitting the walls settle below.

Electrostatic precipitators are the most effective method purify exhaust industrial air. They also install gravel and coke filters, which are wetted with water. Ejections are used to purify industrial air from explosive particles. They consist of 4 chambers.

Requirements for cleaning systems

General ventilation must meet a number of requirements. Any processes in enterprises are accompanied by the release of certain substances into the air. Installation of ventilation must be carried out in accordance with sanitary standards.

Installing quality equipment will help to avoid many problems. Ventilation system makes it possible to control the microclimate. The type of ventilation system should be selected in accordance with the parameters of the premises, purpose and number of employees.

It is necessary to use ventilation systems in each individual production room, even if it is not supposed to be occupied.

In addition to purifying the air and maintaining microclimatic conditions inside the industrial area, ventilation makes it possible to purify the exhaust air before it is released into the atmosphere. All air exchange standards are prescribed in SNIP.