Supply ventilation device in production. Features and procedure for calculating exhaust and supply ventilation. According to the principle of operation

The fundamental difference between industrial ventilation is that the equipment copes with the maintenance of large premises, often with very difficult microclimate conditions. Harmful substances, hot steam or dust can be released into the air. The main task exhaust ventilation production facilities quickly "catch" all unwanted impurities and remove them without harming the environment.

Types of room ventilation

According to the method of air movement, there are two types of ventilation:

mechanical;
natural.

According to the principle of operation, all ventilation units are divided into:

Supply(for submission fresh air), can be local (oasis, curtain or air shower), as well as general (inflow directed or dispersed).
exhaust(evacuate exhaust air), are general or local.

Natural ventilation in industrial buildings

Any natural supply or exhaust ventilation of a production facility operates using the difference in temperature and air pressure in the workshop and on the street. This means that the driving force of natural traction is wind and thermal pressure.

Due to the temperature difference, expanded warm air masses are forced out of the workshop, and clean, cold air masses are drawn in their place. An area is formed from the windward region high blood pressure, enhancing the flow of fresh air from outside. On the leeward side of the building, on the contrary, the pressure is always lowered, which contributes to the outflow of exhaust air. Physical laws are successfully used for ventilation of enterprises with intense heat release. But not in all cases, a powerful air exchange guarantees the creation of all the necessary conditions for the work of personnel.

The more noticeable the temperature difference near the floor and the ceiling of the workshop, as well as the higher the room, the more efficient the system will work.

If there are gaps in the walls and windows of the workshop, doors or gates are often opened, drafts are likely to occur and the temperature drops. In the summer, in areas remote from doors and windows, the norms of ventilation of industrial premises are violated.

Air aeration in the room

Aeration in some cases creates an effective air exchange based on natural draft. For its implementation, aeration lamps are installed - specially designed ventilation elements.

Sometimes, during the construction of a production facility, ventilation is not calculated, the equipment is not installed. Then it is possible to place shafts and channels operating due to thermal pressure in an already finished workshop. The exits of the mines are covered with deflector heads. The wind blows over the deflector and forms a rarefaction area in the pipe, increasing the suction of air. A similar system is widely used in agricultural and livestock buildings, forges, small bakeries. The pipe is installed on the highest ledge of the roof.

Aeration is one of the most efficient examples of natural industrial ventilation. It is used in industries with abundant formation of gases, poisons and heat.

Natural ventilation device in production

In serviced buildings, 3 levels of openings with specially designed vents are equipped. The first two rows of openings are located at a height of 1-4 meters from the floor. Light-aeration lamps with adjustable vents are installed in the roof.

In summer, streams of clean air enter through the lower transoms, while dirty ones go up. In the cold season, air penetrates through the middle row of vents and, warming up, reaches the level of the staff.

The intensity of ventilation is regulated by different positions of the vents. Calculating the ventilation of the production premises, determine the area of the vents, openings. Since the worst time for the system to work is warm, calm weather, it is taken as a reference point.

In windy weather, natural traction works better. But with a combination of a certain force and wind direction, reverse thrust can be created.

Mixed with dust and gases, clean air is directed to the areas where people are located. To prevent the spread of dust and dirt, lanterns of an inflatable design with wind protection are installed.

In the hot season, the supply air is cooled by spraying in it cold water from nozzles located in the area of the vents. The air cools and the humidity increases slightly.

There are some requirements for buildings with natural aeration:

its perimeter must be open to air access;
aerated one-story workshops or located on upper floors high-rise buildings.

It is very difficult to mount natural ventilation in multi-span industrial premises. With a workshop width of more than 100 meters, delivering clean air to the center of the building is almost impossible. Then, for aeration, Baturin's non-blown lanterns are installed with a separate channel for exhaust and inflow. In winter, such a system can cause an undesirable temperature drop in working area production premises. Therefore, in multi-bay workshops, forced ventilation with inflow heating is usually installed.

All elements of aeration are controlled mechanically.

The advantage of this type of ventilation of industrial premises is the possibility of providing powerful air exchange.

Another plus is the low cost of mechanisms.

Flaws:

dependence on the weather;
complexity of management;
the impossibility of providing remote workplaces with fresh air.

Aeration, as a type of ventilation of industrial premises, is unacceptable if the technology involves the spread of harmful impurities and dust. Because filtering waste air masses impossible.

Forced ventilation in industrial premises

The supply or exhaust ventilation schemes of industrial premises on a mechanical draft make it possible to bring the parameters of the air supplied to the premises to the required ones (moisten, filter, cool, heat and neutralize the air).

Advantages forced ventilation:

its work is not related to the temperature outside;
it is possible to supply, remove air from the required point;
it is possible to change the ventilation rate of the production premises within any limits;
it is possible to make an accurate calculation of the exhaust or supply ventilation of the production room.

Among the types of ventilation used today in industrial premises, forced exhaust ventilation is the most widespread.

Ventilation of industrial premises limits the spread of dirty air and removes it directly from the source of its occurrence.

The quality of the local ventilation of the production premises is affected by the correct selection of equipment, the shape of the air inlets, and the degree of rarefaction of the atmosphere.

All types of exhaust units for ventilation of industrial premises consist of such components as:

suction (air inlet);
fan;
air ducts;
filters;
exhaust channel.

The entire volume of dirty air must be captured by the air inlet and then transferred through the local ventilation system of the production facility.

Types of industrial air inlets

Suction or air intakes for ventilation systems are of two types:

closed;
open.

Ventilation air inlets open type consist of:

protective cover;
exhaust umbrella;
on-board or articulated-telescopic suctions (installed directly at the workplace);
movable air inlets.

Such receivers are distinguished by the fact that the opening for the intake of dirty air is located a little further from the place of its release.

The protective anti-dust casing eliminates the column of dust (the so-called dust torch), which is formed, for example, in carpentry: during grinding, polishing, grinding machines. The device contains a visor and is installed across the movement of dust particles.

The multiplicity of local ventilation of the production room is calculated based on the speed and diameter of the grinding or grinding wheel.

Exhaust hoods reduce the distribution area and remove hot air containing dangerous impurities and rising upwards according to the principle of convection. The size of the umbrella should completely cover the area of the hot air source. Umbrellas are made with or without overhangs. Overhangs are made of rigid sheets or dense canvas. Open umbrellas are more convenient, as overhangs do not interfere with personnel access.

In hazardous industries, the speed of the air flow entering the umbrella should be from 0.5 meters per second and higher. If the umbrella removes hot air without impurities, the speed should be between 0.15 and 0.25 meters per second.

Air inlets in the form of slots or side suctions are installed on pickling and galvanizing baths. The air moves over the bath and draws out the harmful fumes of alkalis and acids before they spread throughout the room.

If the width of the bathroom is small (up to 70 cm), single-sided suctions are installed.

Wide bathtubs are equipped with double-sided suctions, as well as structures that blow off evaporation from the surface of the liquid, “with an overflow”.

The volume of air passed through such devices depends on the surface area of the liquid, the degree of toxicity of the vapor, and the temperature of the liquid. As the couples quickly destroy metal constructions, ventilation of industrial premises in this area is made of sustainable materials, such as PVC.

In welding and soldering shops, suctions are installed on vertical or beveled panels with many holes.

Telescopic and articulated suctions are very common. Thanks to the retractable pipe, the suction end can be brought closer to the desired location.

In workshops with semi-automatic welders and carbon dioxide soldering irons, suctions are mounted directly into the tools. Such equipment is effective at air exchange up to 20 cubic meters per hour.

If the place of work of the welder is not fixed, mobile suctions are used, some of them are attached to the welding machine on suction cups.

Closed type suctions:

fume hoods;
cabins;
shelter boxes;
cameras.

Fume hoods are installed in workshops with abundant release of toxic fumes and gases.

Shelter boxes do not provide for open openings and are used in industries with radioactive and highly toxic substances. The worker performs all manipulations with rubber gloves and built-in sleeves or mechanical devices.

Local exhaust ventilation in industrial premises with complete isolation of sources of hazardous emissions is called aspiration and is considered one of the safest and most effective schemes.

Types of industrial fans

Air in forced ventilation systems is driven by mechanical devices: blowers powered by electricity. Most often, radial or axial models are installed.

A radial or centrifugal fan is also called a "snail" in the form of a housing into which a wheel with blades is built. During the rotation of the wheel, air enters the housing, changes direction and is supplied under pressure to the air duct.

Exhaust air is often saturated with harmful and aggressive components and even explosives. Depending on possible impurities, fans are used:

standard type for air temperature up to +80 degrees with a small amount of dust;
anti-corrosion type - for alkali and acid vapors;
with protection against sparks - for explosive air mixtures;
dust - are used if the dust in the air is more than 100 milligrams per cubic meter.

Fan numbers indicate the diameter of the wheel, expressed in decimeters.

Axial fans are inclined blades installed in a cylindrical housing. During operation, the air moves parallel to the axis of the fan. Such models are installed more often in medium-sized networks, emergency exhaust ducts and in mines. Their advantage is that one fan can supply air in two opposite directions, carrying out both exhaust and inflow.

Air is supplied to the required points through air ducts. Most often they are made of sheet metal, and when working with aggressive substances - from plastic, ceramics and other stable materials.

Dust collectors and filters for industrial work

The quality of air emissions into the atmosphere is regulated by the requirements for ventilation of industrial premises. Therefore, dirty air from industrial plants must be filtered before being released into the environment. One of the most important parameters calculated for the ventilation of a production facility is the efficiency of air purification.

It is calculated like this:

Where Kvh is the concentration of impurities in the air before the filter, Kout is the concentration after the filter.

Sometimes a single dust collector or filter sufficiently cleans the air, then cleaning is called single-stage. If the air is very polluted, it is necessary to organize multi-stage cleaning.

The type of purification system depends on the amount of impurities, chemical composition and forms.

The simplest design of dust collectors is dust settling chambers. In them, the speed of the air flow is sharply reduced and due to this, mechanical impurities settle. This type of cleaning is only suitable for primary cleaning and is not very effective.

Dust chambers are:

simple;
labyrinth;
with a baffle.

To catch dust with particles larger than 10 microns, cyclones are used - inertial dust traps.

Cyclone- This is a cylindrical container made of metal, tapering from below. Air is supplied from above, dust particles under the influence of centrifugal forces hit the walls and fall down. Clean air is removed through a special pipe.

Two small cyclones installed one behind the other increase the cleaning efficiency by 90% compared to one large one.

To further increase the amount of trapped dust, water is sprayed into the cyclone body. Such devices are called cyclones-washers. The dust is washed off with water and sent to the septic tanks.

The modern type of dust collectors is rotary or rotoclones. Their work is based on a combination of Coriolis forces and centrifugal force. The design of rotoclons resembles a centrifugal fan.

Electrostatic precipitators- This is another way to clean the air of dust. Positively charged dust particles are attracted to negatively charged electrodes. Pass through the filter high voltage. To clean the electrodes from dust, they are automatically shaken from time to time. Dust gets into the bins.

Water-wetted gravel and coke filters are also used.

Medium and fine filters are made of filter material: felt, synthetic non-woven materials, fine meshes, porous fabrics. They catch the smallest particles of oils, dust, but quickly clog and require replacement or cleaning.

If the air needs to be cleaned of very aggressive, explosive substances or gases, ejection systems are used.

The ejector consists of four chambers: rarefaction, confuser, neck, diffuser. The air enters them under high pressure, entrained by a powerful fan or compressor. In the diffuser, the dynamic pressure is converted into static pressure, after which the air mass is carried out.

Supply ventilation in production

The norms of ventilation of industrial premises are specified in SNiP 41-01-2003. Before entering the room, the air should be treated: cooled or warmed, filtered from dust, and sometimes its humidity should be increased.

Supply ventilation device:

air intake;
air ducts;
filters;
heaters;
fan;
air distributors.

When installing the ventilation of the production room, a supply chamber is organized to accommodate the heater, filter and fan.

Air inlets are located at a height of 2 m above ground level, in places remote from pollution sources, sometimes above the roof of the building. When choosing a place, the direction of the winds is taken into account. Outside, the air intakes are covered with blinds, grilles or umbrellas.

The supply air is cleaned by the filters of the different type, usually made of non-woven materials.

The air in winter is heated by shadows or heaters. The heat carrier is water or electricity. If humidification is required, irrigation chambers are installed, where a finely dispersed fraction of air is sprayed. The air is cooled in the same way.

Local supply system in the room

The requirements for ventilation of industrial premises are not always met by general ventilation. And then a local supply system is installed.

Types of local supply ventilation:

air-thermal curtains;
air showers;
oases;
air curtains.

air shower is a stream of clean air directed towards workplace. Its purpose is to increase the heat transfer of the employee's body and prevent overheating.

Shower installations can be:

stationary;
mobile.

Showering is organized in hot shops, as well as when infrared exposure of personnel is more than 350 W/sq. meter.

The norms of ventilation of industrial premises of this type depend on the severity of the work, the air temperature in the workshop and the intensity of IR radiation. On average, the air temperature in the air shower is from +18 to +24 degrees. The flow moves at a speed of 0.5 to 3.5 meters per second. The speed is directly proportional to the air temperature and the radiation intensity. And the temperature of the inlet flow is inversely proportional to these indicators.

To change the direction of the air flow, special rotating pipes are attached to the ends of the air ducts.

Air oases serve the whole section of the workshop, which is fenced off from the rest of the area with light screens. In the area, the air moves at the calculated speed and temperature. In the oasis, the ventilation rate of the industrial premises is carefully calculated.

Air-thermal and air curtains are designed to prevent hypothermia of employees and to cool rooms through open doors or openings.

There are 2 types of curtains:

with supply air heating;
without heating.

General ventilation is necessary in cases where moisture, heat and pollution enter the entire volume of the workshop and it is impossible to comply with the norms of ventilation of industrial premises with the help of local measures. With a general exchange ventilation system, the exhaust air in the production room is diluted with clean air to the requirements of sanitary and hygienic control. This is not an economical and not very efficient system.

Industrial ventilation is a process whose purpose is to comply with technological and hygiene requirements in production, including air in the workplace.

Task and functions

The design and installation of industrial ventilation solve several problems, the main one being the determination of air exchange processes. After the necessary calculations, specialists determine the conditions of the technical process in production, the volume and nature of harmful emissions, and, taking these data into account, design a ventilation system.

It is almost impossible to accurately determine the necessary data. A lot here is played by the erudition and experience of specialists: technologists, designers, engineers. If you determine the amount of air removed from the room incorrectly, even the most expensive and modern ventilation will not give the desired effect.

Why is industrial ventilation necessary?

Its main function is to provide comfortable conditions for the stay of employees of this production workshop. In addition, due to competent ventilation, the necessary technological processes and requirements for the storage of a particular type of product are provided.

It is with the help of ventilation systems that enterprises create optimal conditions, in accordance with sanitary standards. They not only increase the efficiency of production and labor productivity of workers, but also improve the quality of products, reducing the rejection rate.

In the process of ventilation, dust particles and excess moisture are removed from the air in the production room, optimum temperature. The air is purified from combustible, explosive and simply harmful to human health substances.

Harmful substances emitted in production

Industrial ventilation and air conditioning purify the air and neutralize Negative influence substances released during production. For example, they successfully cope with excessive heat and moisture release, remove substances in vapor and gaseous form, including various toxins that are harmful to health.

Industrial ventilation solves the problem of excessive dustiness of premises, when dust particles are released into the air in an amount exceeding the maximum allowable values. The same applies to smoke particles and aerosol substances. Finally, during the production process, the smallest particles of liquid are concentrated in the air in the form of fog or hollow drops of gas bubbles.

All these "harmful things" are carried by air. And the ventilation system just determines the desired air flow, forming temperature fields. It constantly removes polluted air from the outside, and blows clean cool air from outside. Such air exchange is carried out by special exhaust equipment.

Design and calculation of ventilation

So, industrial ventilation directly affects the efficiency of work. Many technical processes depend on its correct calculation and functioning. Therefore, before installing industrial ventilation, experts carefully calculate the intensity and frequency of air renewal in the room. Here are the factors that are taken into account.

The area of the production premises, its dimensions and height;
Design features and architectural nuances;
Purpose of an industrial facility;
The size and type of installations that release harmful substances into the air;
The number of workers permanently located in the premises and the duration of their stay;
Location of workplaces;
The number of units of equipment and the level of its workload, as well as much more.

Industrial and others major cities organized according to specific requirements. For example, a small room with an area of less than 20 square meters should receive at least 30 cubic meters of clean air per hour per person.

Equipment in the ventilation system

There are two main types of equipment in the ventilation system: exhaust and supply. The exhaust, or industrial exhaust ventilation, is responsible for the removal of dirty air, and the supply air is responsible for supplying clean air. They can work either simultaneously or randomly. However, the amount of air supplied and exhausted is always the same.

Depending on the method of air injection, industrial ventilation is divided into mechanical and natural. The latter is carried out due to the natural movement of air inside the room, due to different pressures and the action of winds. Mechanical ventilation, respectively, works due to installed fans.

To increase the safety of the technical process of ventilation, in some cases, an emergency or backup system is installed.

Forced ventilation

So, industrial supply ventilation serves to replace the dirty air removed from the room with clean, injected from the outside. It is divided into two types: local and general exchange.

General ventilation

This system is in the most polluted areas. With its help, air is supplied in quantities sufficient to dilute harmful substances up to the maximum allowable values. When it comes to thermal values, the temperature is lowered to the limit in order to prevent an excess of heat.

local ventilation

Serves to create specific settings in a well-defined room. Technically, it is implemented using special structures, including:

air curtain - a flat air jet that does not allow harmful substances from the air to enter a certain area;
air shower - a directed stream of air, for example, on an industrial installation or on a worker;
air oasis - a system for filling a certain part of the room with clean air.

So, general industrial ventilation neutralizes only excess heat and reduces the concentration of harmful substances in the air. If during the production process there is a significant release of harmful gases, vapors and dust, a mixed system is used, based on general ventilation, but with local exhausts.

It is not recommended to install a general ventilation system at enterprises with increased dust and gas emission. In this case, the more powerful the equipment, the stronger the harmful substances will be carried around the production area.

What are industrial fans?

Today there are Various types fans. Here are the main ones.

Axial. The most common type on Can be installed not only in industry, but also in the system. The design of this device is familiar to everyone and is a casing with blades.
Roof. As the name implies, it is installed on the roofs of shops, warehouses, and other manufacturing enterprises. It is also used in the ventilation system of residential complexes.
Channel. Often used in offices, mounted under false ceilings or in air duct networks, directly in the ventilation duct.

In addition to the usual ones, there are also fans with special functions.

Soundproof. They are placed in rooms where even the seemingly minimal noise from the fan needs to be neutralized. For example, in medical institutions or libraries.
Heat resistant. They can operate in a wide temperature range - from minus 20 to plus 100 degrees. They are made of highly durable materials and covered with a special fire-resistant paint.
Explosion resistant. They are used in enterprises whose activities are related to the production of explosive gases. They are made of a special material silumin, resistant to corrosion and particularly durable.
Resistant to aggressive environments. Indispensable in chemical plants or laboratories where there are chemically aggressive substances in the gaseous state.
For smoke removal. Such fans are often seen in emergency ventilation systems. They do an excellent job of removing polluted air and reducing smoke in case of fires.

Industrial ventilation systems are an important part of any production, and competent specialists should be engaged in their design and installation.

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 endure physical activity.

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Solution

Ventilation of industrial facilities is essentially the supply of fresh air and the removal of exhaust air. And it includes a number of solutions.

The first stage is planning. And for this it is necessary to take into account several important conditions: the presence of harmful fumes in the premises, gas contamination and temperature conditions.

To solve the tasks, it is necessary to take into account the necessary conditions labor, as well as build on the parameters of the premises and its specifications.

Most often, in large rooms, supply and exhaust ventilation with air cooling or heating is used.

Currently, there are many ventilation systems that differ in functionality and cost. Often this is a specific solution for each a separate room. It is thanks to this that we get an efficient, economical, and ideally coping with the tasks set. It should be understood that the ventilation system is a very complex mechanism that not only provides clean and fresh air in the room, and therefore high performance of not only equipment, but also employees, as well as their well-being, and also allows you to control many parameters to create optimal climatic conditions depending on the time or part of the room. The ventilation system can be controlled mechanically or electronically, but mixed types are also possible.

The task of industrial ventilation

The main task of industrial ventilation is to ensure the constant presence of clean air in the premises (without impurities, odor and harmful components). This is ensured in 2 ways: by removing polluted air masses from the workshops and by providing an influx of fresh air. The second task is to maintain a certain microclimate. This includes requirements for temperature regime and air humidity. These requirements are especially relevant for industries accompanied by a large release of heat, moisture and harmful fumes.

A professionally designed ventilation system contributes to the following benefits:

staff get sick less
labor productivity increases
a favorable microclimate is maintained
moisture does not accumulate on the equipment, the metal does not oxidize or corrode
compliance with the requirements for production processes.

Exhaust aeration in production

Air ducts are mainly used for ventilation of local spaces inaccessible to infiltration flows. The movement and distribution of air occurs without external coercion, only under the influence of temperature differences and atmospheric pressure outside and inside the room. To increase the efficiency of aeration, deflectors are installed at the outlet, special expansion nozzles that draw the exhaust air out of the room. This is also facilitated by window transoms and ajar skylights.

IN summer time the role of supply air channels is performed open gate, openings in external walls and doors. In the cold season, in warehouses up to 6 meters high, only openings are opened at a height of at least 3 meters from the zero mark. With a height of more than 6 meters, the bottom of the ventilation openings is designed at a distance of 4 meters from the floor level. All openings are equipped with water-repellent visors, which, moreover, deflect the supply air jets upwards.

Supply and exhaust aeration

Extraction of polluted air occurs due to transoms and ventilation shafts. Transoms act as a kind of thermal damper, the opening and closing of which regulates the air pressure in the ventilation streams. As an additional pressure regulator, special holes are designed, equipped with louvered doors:

slightly above floor level - stimulating air flow,
just below the ceiling level - optimizing its outflow.

The volume of circulating air is proportional to the area of open transoms, openings and vents.

Note

If the concentration of harmful substances in the outdoor air exceeds the maximum allowable limits by 30%, natural ventilation is not used.
The elements of the upper hood are installed approximately 10-15 degrees below the ridge on the roof. This reduces the risk of their destruction.

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 are necessary additional elements 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 a difficult task as the calculation, design and subsequent installation of ventilation should be performed by qualified specialists who have a wealth of knowledge and years of experience behind them.

Classification of industrial ventilation by type of action

There are different typesindustrial ventilation. They are classified according to the following parameters:

the method of organizing the inflow and outflow of air masses (natural, forced);
by functionality (supply, exhaust, supply and exhaust);
method of organization (local, general exchange);
design features (channelless, channel).

The simplest and most cost-effective is natural ventilation. It is based on the laws of physics, when the warmer layers of air, rising up, displace the cold ones. The main disadvantage of such systems is the dependence of the time of year, weather conditions and a limited scope (suitable for a limited range of industries). To organize natural ventilation in production shops, 3 levels of adjustable openings (windows) are arranged. The first 2 are arranged at a height of 1-4 m from the floor, the 3rd level is under a stream or in a light-aeration lamp. Fresh air enters through the lower openings, and dirty air is forced out through the upper ones. The intensity of air exchange is regulated by opening/closing the vents. Natural ventilation can only be used for one-story buildings.

Forced ventilation- a more efficient system, including a set of equipment and engineering networks. However, you have to pay for efficiency, as it is associated with the purchase of expensive equipment and the consumption of a large amount of electricity.

Only supply or only exhaust ventilation is used extremely rarely (mainly in industries where air pollution is low). Much more common supply and exhaust systems providing more uniform air exchange.

General ventilation organized in large factories. Depending on production processes and air composition, it can be used in combination with other systems. local ventilation, unlike the general exchange, monitors the purity of the air in certain areas - for example, above the welding or painting area. This type is selected if the general exchange cannot cope with ventilation in all rooms.

What gives a combination of local exhaust and supply general exchange systems? Taking in polluted air, the exhaust system does not allow it to spread throughout the room, and the supply system provides an influx of fresh air (it can be equipped with filters and a heating system).

duct ventilation involves the organization of boxes or pipes of large cross-section, designed to transport air. Channelless systems - a set of fans and air conditioners built into the openings of walls or ceilings.

Design of ventilation of production shops

Design industrial ventilation systems has its own specifics. There is no universal equipment that can meet the needs of all types of industries. When designing, a lot of data is taken into account. The algorithm for solving the problem is as follows:

Calculation of the required air exchange.
Selection of equipment that supports the calculated parameters.
Calculation of air ducts.

At the first stage of design, a technical task (TOR) is developed. It is compiled by the customer and includes requirements for air parameters, features technological processes, tasks of the system.

architectural plan of the object with reference to the area;
construction drawings of the building, including a general view and sections;
the number of employees in one shift;
facility operation mode (one-shift, two-shift, round-the-clock);
features of technological processes;
potentially dangerous zones with reference to the plan;
required air parameters (temperature, humidity) in winter and summer.

The calculation of the required air exchange is carried out in the following areas:

supply of fresh air according to sanitary standards (according to the norms per person 20-60 m³ / h);
heat assimilation;
moisture assimilation;
dilution of air to the maximum permissible concentrations of harmful substances.

The largest air exchange obtained as a result of the calculations described above is taken as the basis.

Using the emergency ventilation system

According to SNiP ("Ventilation of special and industrial buildings") in hazardous industries, it is necessary to provide emergency ventilation system. An emergency situation may arise in the event of an emergency release of explosive or toxic gases, a fire. She represents completely self-installation exhaust type and is calculated in such a way that when working with a conventional system, 8 air changes are provided in 1 hour.

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 meet the requirements sanitary norms, quickly respond to emergencies and save significant funds.

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. To the most effective measures can be attributed to 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 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 occurrence emergencies 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.

Optimal air parameters for some industrial premises according to the conditions of work or storage of materials

Type of production and premises	Temperature	Relative Humidity

Libraries, book depositories
Museum premises with exhibits made of wood, paper, parchment, leather
Studios of artists with paintings on easels
Warehouses of paintings in museums
Fur storage rooms
Leather storage rooms

Engineering enterprises
Metal Laboratories
Thermal constant rooms for precision work of various groups




Extra clean rooms for precision work:
Shop of precision engineering
Workshop for winding transformers and coils, assembling radio tubes
Workshop for the manufacture of electrical measuring instruments
Selenium and Copper Oxide Plate Processing Workshop
Optical glass melting shop
Lens grinding shop
Computer rooms with built-in fans:
Parameters of the air supplied inside the machines
Air parameters at the outlet of machines
Room air parameters

Hospitals
Surgical
Operating


Woodworking industry
Shop machining tree
Carpentry and Procurement Department
Workshop for making wooden models
Match production
Drying matches

Printing production
Sheetfed offset printing workshop
Roll Paper Rotary Printing Workshop
Offset paper warehouse
Warehouse of coated paper in sheets
Rotary Roll Paper Warehouse
Workshops: bookbinding, drying, cutting, gluing paper

photographic production
Photographic film processing rooms
Film cutting department

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 the workplace is 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 extremely necessary 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 ventilation is very effective and at the same time its organization does not require huge financial investments, since the removal of contaminants from the air is achieved at a low flow rate.

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 exits, 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 it is required 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 system of air ducts for 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 the vents in a natural way.

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. And a significant drawback is the impossibility of complete control over air flows, as well as a 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 works are among the most harmful types of work for human health, nitrogen, carbon, fluorine oxides and many other various chemical compounds are certainly formed in 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 perform high-quality technological processes, aimed at observing the basic safety regulations, and also contributes to the proper organization of each workplace, and most importantly, eliminates harm to the health of an employee involved in production.

Creating a truly comfortable and cozy atmosphere in the workplace not only increases the productivity and efficiency of the labor process, but is also a prerequisite that the sanitary authorities put forward. Therefore, ventilation systems are just as important in production as are the elements of the central heating system or the services of the electrical network. The installation of such systems is a rather complicated and time-consuming work, so they usually do not do it yourself, but trust professionals with solid experience. In any case, knowing about the principles of operation, design and development does not hurt anyone.

Air-conditioning of premises of various sizes in production is carried out using the most complex systems, which, in addition to the air duct, also include various heaters, filters, coolers, recuperators, fans and other elements. The ventilation system, regardless of the type of production process, area and size of workshops and air pollution, must perform the following functions:

Providing fresh purified air to the employees of the enterprise.
Removal of unpleasant and extraneous 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.

Sidebar: Important: In industrial and production workshops, mechanical and natural ventilation is used for normal air exchange. When designing, it is necessary to take into account various regulatory documents regulating the state of factory and factory shops.

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

Only highly qualified specialists, certified engineers and professionals should be allowed to work in the development or in the production room. At the same time, it is necessary to take into account climatic and weather conditions, the number of workers, the size of the premises, production features and many other nuances and features.

The elements of any ventilation system are air ducts, exhaust and supply devices, as well as equipment that helps create a comfortable and cozy microclimate inside the room (this includes humidity stabilizers, as well as heaters and air conditioners).
For normal ventilation of various objects in production conditions, it is necessary to use such equipment that is able to remove particles of dust, aerosol and gas from the air, which appear as a result of the operation of complex equipment.
In some industries (such as pharmaceuticals or the production of high-precision electronics) the creation of specific working conditions is required, therefore, all kinds of additional elements are added to the powerful ventilation system, such as special filters and high-power air conditioners.
According to the operating instructions for certain types of equipment, those workshops and areas where fumes that are hazardous to human health may be present should be additionally equipped with extractor traps that are separated from the general workshop network.
Devices that carry out hygienic and sanitary control of ventilation systems are part of air exchange systems, and depending on their indications, special equipment can be connected that removes various toxic impurities and purifies the air.
When designing 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 the cold air is used to cool machines and other equipment.

Table: heat consumption of the ventilation system

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

General exchange ventilation is responsible for the normal replacement of air masses in the room. The most typical example is an ordinary axial fan, which is inserted into a wall or window duct. Based on such parameters as the length of the duct and the cross section, the appropriate power of the equipment is selected.
(or individual type) - allows you to purify the air from 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 to exclusively in force majeure cases, therefore the standards here differ from those generally accepted in production and will not be considered in this context.

Ventilation is also mechanical and natural. The natural scheme carries out the removal and inflow of air masses through draft, which occurs due to the difference in temperature and pressure inside and outside the production room. The effective functioning of such a ventilation system is affected by:

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

Varieties of the ventilation system

The natural ventilation and ventilation system is silent, environmentally friendly and economical. However, changing weather conditions can have a very negative impact on its effectiveness. Mechanical ventilation is free of such a disadvantage, which is able to move the air flow through an air duct of any configuration and section to any distance. In such cases, it is often carried out the installation of additional equipment that heats the air, and also humidifies, dries or filters it if necessary. To date, the most popular combined ventilation systems, which use elements of both mechanical and natural systems.

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

The implementation of mechanical ventilation of industrial and industrial premises requires a fair amount of electrical energy, so this method is not always cost-effective. The advantage of this method of ventilation is the independence of air flows and temperature from conditions. environment. The air in such systems is often heated and also cleaned or, if necessary, cooled. Today, the most popular is the combined ventilation system, which combines elements of mechanical and natural ways of ventilating the room.

The ventilation standards include certain provisions, according to which the ventilation system must be located in absolutely all production workshops and premises. Moreover, regardless of functional features the area occupied and the number of employees on it. The capacity of the ventilation equipment should be sufficient for the maximum fast cleaning indoor air in case of emission of harmful substances or smoke. The development of a project, according to which the work of the ventilation system will be further implemented, should be carried out by professionals who are able to do this in full compliance with applicable laws, documents and regulations. During design, the following parameters must be taken into account:

inside a workshop or production facility.
fire safety conditions.
Air humidity indicators.
The presence and number of toxic and poisonous substances that pollute the environment.
Climatic features.
Space and functionality.

It is worth noting that providing each employee with air is a norm, the implementation of which is monitored by various authorities and services. The norm is thirty cubic meters per hour on an area less than or equal to forty square meters. For large industrial complexes, such standards are calculated separately. When calculating the technical characteristics of the ventilation system, it is worth considering the following nuances:

The ventilation system should not be a source of noise that is strongly emitted even during operation. technological equipment and machine tools. The noise level should be at a medium or low level, otherwise a long stay in the workshop 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, then it is most likely that it itself is the cause of increased pollution of the surrounding air space. To ensure that the ventilation system does not act as 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 type include compliance with sanitary and hygienic standards due to the assimilation of excess 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 comfortable conditions that comply with all established norms and rules. In the event that the room temperature is low, then the supply-type ventilation system can solve this problem by heating the supply air masses.

The simplest device that is installed in various workshops and industrial premises is a fan that has an air vent. Due to the fact that the amount of various harmful and toxic impurities in enterprises, as a rule, is higher than the norm, the use of only one ventilation system is not always effective. To maximize the safety of employees, modern factories use both natural and mechanical systems.

In today's market, there are a lot of various systems, ventilation, which allow you to create the safest and most comfortable working conditions within the workplace. The widest selection of devices that differ from each other both in functionality and in price will satisfy the needs of even the most demanding customer. During the design of a complex industrial ventilation system, it is necessary to install both supply equipment, which is the guarantor of the supply of clean air to the space of workshops and plant premises, and special exhaust units. With their help, you can remove from the workplace air saturated with pathogenic bacteria, toxic substances, dust, smoke and other harmful elements. It is selected based on the characteristics of production.

They choose one or another variation of equipment on an individual basis, with the obligatory consideration of the differences and features that are inherent in a particular industrial or construction large facility.

The ventilation system must have the following parameters:

Profitability.
Efficiency.
Reliability.
Payback speed.

Thanks to clean and cool air, you can achieve not only Have a good mood, health and performance of employees, but also low wear of technological equipment and various tools. It is economically feasible when drawing up a project to add a device that is connected to the ventilation system and provides a comfortable indoor climate.

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

Thanks to the use of supply or exhaust circuits, you can easily bring the humidity indicators at the enterprise to normal, as well as neutralize, heat, cool, filter or humidify the air. A huge advantage of forced ventilation is that its operation is not affected by external conditions and weather factors. Air removal and supply can be made from the required point. You can make accurate calculations of supply or exhaust ventilation and draw up a schedule of costs.

The operation of ventilation systems is affected not only by the competent selection of equipment and installation, but also by the rarefaction of the atmosphere, the shape of the air inlets, the correct installation of filters, fans, air ducts and other elements. In enterprises, it is most advisable to install axial or radial blowers powered by electricity. Thanks to such a solution, it is easy to provide employees with a clean airspace in the workplace, devoid of harmful impurities and toxic elements. For better filtration today, electrostatic precipitators and other components are often used, which can maximally secure even an environment saturated with aggressive chemical compounds and components.

Air conditioning in enterprises and industries makes it possible to achieve a normal microclimate, which is especially important for the optical industry, instrument making, electric vacuum industry and other areas where maintaining a certain humidity in the room is a very important point. To set up and install the ventilation system, it is best to contact professionals with experience and knowledge in their field.

Ready-made ventilation systems need periodic cleaning, because if the channels are clogged, be in production shop or the room becomes unsafe due to the high concentration of dust particles and harmful elements. For maximum efficiency Today, various filters are used, 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 installation

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 structure and efficiency directly during operation. That is why for the installation of individual elements of the air exchange network it is necessary to attract highly qualified specialists who have the appropriate knowledge and experience. It is also important to choose the right place for the installation of equipment, such as filtration systems, fan units, heat exchangers and other units.

In industrial and industrial premises, they are usually attached directly to the ceiling. If desired, they can be hidden using hanging decorative panels. In those premises 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, the following types of air channels are used in construction:

Rigid. For their production, materials such as fiberglass, multilayer aluminum, galvanization and others are used. Of these elements, the installation of virtually the entire ventilation system is carried out. The only exceptions are special parts of a shaped sample, which are used for branching, contours and turns. To transport air that contains various harmful impurities, it is worth using air ducts with walls of increased thickness.
Flexible. Their main purpose is the communication of various sections and openings with the main air ducts. For the design of the local ventilation system, the purpose of which is to purify the air in the immediate vicinity of the workplace, aluminum sleeves are often used.

The installation of ventilation ducts in industrial and industrial premises is carried out in the following order:

To begin with, the parameters of the wall thickness and the cross section of the air channels are calculated, after which, based on the data obtained, the mass of each element of the ventilation system is calculated. Sometimes the installation of square ducts is not possible due to insufficient space. Therefore, faced with a similar situation, it is worth using rectangular ducts to solve the problem.
Then, at the joints, you need to designate the fixation points for the air ducts. Thanks to this, you can easily calculate the required number of fasteners, brackets and other fittings. It is worth remembering that for mounting brackets it is undesirable to allow oscillations of long sections of the network to occur directly during the passage of air through them. It is best to provide the structure with an excess number of fasteners, since in this case they will withstand even increased loads without problems.
When the installation of the main channels has been completed, it is possible to proceed with the installation of separate suction and spray devices. For such cases, it is recommended to use special hoses with flexibility and the desired cross section.

conclusions

Installation and design of industrial ventilation systems is a responsible and complex process. Finished project must comply with strict building codes and current rules. The health of employees and the performance of the entire team directly depend on this.