Ventilation of industrial premises - types of systems, requirements. Ventilation systems for industrial premises: exhaust, local, natural Installation of exhaust hoods in production

There is no doubt about how important industrial ventilation is, since it is a mandatory factor for the safety and health of workers at work. Quite often in industrial enterprises people work with compounds, metals, and impurities that are harmful to health, and the ventilation system for such premises must be at a high level.

Types of ventilation systems in production

Of course, production facilities place not only high demands on ventilation. Given the large area and often difficult working conditions, ventilation of industrial premises is carried out in slightly different ways than for a residential building, for example.

The following types of industrial ventilation can be distinguished:

1. Natural.
2. Mechanical.

Depending on which circulation method is chosen for a given room, ventilation is divided into local and general exchange.

And the systems themselves for air ventilation in industrial premises are divided into:

• exhaust units - which forcefully remove large volumes of air from a workshop or any other room.
• air supply units - they, in turn, ensure uninterrupted supply of fresh air into the ventilated room.

Production premises with natural ventilation

Natural ventilation is based on air exchange based on temperature differences. This indicator affects, first of all, the different specific gravity of air, inside the production workshop and outside. The efficiency of such a system depends on the difference between these parameters. That is, the greater the difference in specific gravity and temperature, the greater the efficiency of this system.

This ventilation system can be organized or unorganized. In the first option, air volumes enter through gaps between windows or doors, as well as when opening vents or doors. The flow of fresh air is improved by installing special ventilation shafts, and the shafts or channels themselves are additionally equipped with special nozzles, they are also called deflectors.

This system, even of an organized type, can only be used in industrial buildings with a small area. It is most often used in agricultural workshops or farms.

In small workshops, natural ventilation is carried out by aeration. Calculation of the ventilation system for industrial premises when using this method consists of placing windows at a certain height, as well as special openings, the size of which depends on the size of the room itself.

For example, a small workshop in which ventilation will be carried out by aeration should be equipped with openings with special transoms. The openings themselves must be mounted in two levels. In this case, the height of the first level should vary from 1 to 1.5 meters from the floor, and the second level from 4 to 6 meters from the same floor.

The ceilings in the workshop should be equipped with transoms in the upper part, with so-called aeration lanterns with transoms that open to the required value.

This method is not applicable for production areas that contain harmful substances or exhaust gas vapors that pollute the atmosphere. Natural circulation does not provide for air purification, so for such rooms more complex ventilation systems must be installed with mandatory filters to purify the air, both in the room and when leaving it.

Industrial premises with mechanical ventilation

Industrial ventilation carried out by this method has greater productivity compared to the natural method. In addition, special equipment is used here that cleans the air coming from outside from dust and dirt, and the exhaust air released into the atmosphere also necessarily passes through a special cleaning system.

These systems are installed in such a way that they do not simply purify the air, but also prevent the emission of harmful dust or vapors directly into the workroom itself.

Elements of installations with mechanical ventilation include air intakes. fans, ventilation ducts, filters for purifying the air from harmful impurities and, of course, a device for exhaust air outflow.

The systems are designed in such a way that air from outside is supplied to the place of the highest concentration of harmful substances. Most often, supply channels are made of ordinary steel. But if there are aggressive reagents in the work shop, for example, alkali vapor, then the installation of supply ventilation ducts should only be made of stainless steel, ceramics or plastic.

During the cold season, large volumes of air entering workshops are usually heated using air heaters. At the same time, to prevent the air from becoming too dry due to heating, it is passed through special irrigation chambers. Passing through these devices, it is moistened by water or steam.

Recycling of industrial premises

Ventilation of industrial premises using this method is carried out by air circulation. When using this method, energy is saved, which is used to heat the air in the cold season. In this case, there is a continuous air circulation. The purified street air entering the room exits through a special installation, is cleaned and again enters the working room.

But the use of such a system also has its limitations. For example, using the recirculation method is prohibited in those workshops where the air may have unpleasant odors or a variety of microscopic fungi. If the work shop contains substances belonging to the 1st, 2nd or 3rd hazard class, the recirculation method is also prohibited.

Air conditioning of industrial premises

In this case, powerful systems are installed in production, which are configured specifically to create a favorable microclimate. The settings set the appropriate parameters for air temperature, humidity and indoor circulation. In difficult working conditions with materials of increased contamination or danger, additional requirements are placed on installations, since they must provide additional ionization of the air and purification from bacteria.

In production, air conditioning is used mainly either to maintain the required humidity (when, for example, work is carried out on precision equipment) or to ensure certain sanitary conditions. As a rule, such capabilities are available only to air conditioning systems.

Ventilation systems for industrial premises based on air conditioning are divided into general and local. In general type systems, the installation is installed in a room specially allocated for it, and the inflow and outflow of air flows is carried out through air ducts. With the local type, the air conditioning unit is installed directly in the workshop, and ventilation is carried out without air ducts.

This method is the most expensive today, both in installation and maintenance. But this is the best option when creating a climate in production premises that is required by hygienic standards.

It is worth noting that practice has shown that these installations pay for themselves over time, since the production environment creates exactly the right microclimate that helps improve staff performance. Improving working conditions affects not only well-being, but also productivity, which quite naturally becomes higher.

As statistics show today, in industries where premises have a high level of heat and gas emissions, more and more enterprises have begun to install these installations. Only powerful equipment can provide those comfortable working conditions in a difficult working environment.

Currently, special requirements are imposed on the ventilation of industrial premises: this includes ventilation equipment, ventilation ducts and shafts, and the efficiency of systems.

Thousands of workers suffer every year from occupational diseases, the main cause of which is harmful substances that appear during the production cycle. Exposure to high temperatures, dust, and various contaminants “accompany” workers in the metallurgical, chemical, mining industries, and more than a dozen other 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 reduce the presence of harmful gases and dust at the place of their production below the WPC, and is advisable as the main means of their localization.

Types and purpose

Local ventilation can be of two types. Supply air - serves to supply air to the devices intended for this purpose: air showers. These devices, in most enterprises, are used to create “islands” of clean air in workshops with a large emission of pollutants. Thermal curtains are used to create an air barrier against cold or polluted air masses when there is a need to frequently open doors. The most widespread in hazardous industries is local exhaust ventilation, designed for local removal of contaminated air, in places where it appears, during a certain production process. A local exhaust ventilation system prevents the spread of harmful substances throughout the production site. The most popular exhaust ventilation equipment in most enterprises is local suction.

Requirements for local suction

The main requirement for local exhaust ventilation systems and suction systems is to prevent contaminated air from entering the human respiratory system and eyes. Besides:

1. They should be simple in design so that personnel can easily install and dismantle the devices for cleaning.
2. Devices for removing harmful substances should not be bulky or bulky, or interfere with the production process.
3. Contaminants and gases that appear during the production process must be removed: volatile substances, vapors - upward, and dust and contaminants heavier than air - downwards.

Main types of air intake equipment used in production

Local suction is part of any modern enterprise. Today there are several types of these devices:

Half-open suction. These are mainly ventilated chambers and fume hoods. These devices provide the highest quality removal of contaminants with minimal air consumption. They come in several types. Devices with top exhaust are used when releasing substances with high temperature or humidity. Cabinets with a bottom intake are designed to eliminate “heavy” polluted air. Portable cabinets with side intake of contaminated air are used to eliminate dusty contaminants.

• A completely open device for sucking contaminated air is an exhaust structure that is located outside the source of their emission. Today, the most popular devices of this type are hoods, suction panels and side suctions. A side air intake device is installed if access to the source of pollution is required from different sides. Exhaust hoods are the simplest version of suction. They are installed in places where harmful substances are released, which tend to rise upward. 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 part of the equipment and is made in the form of a cover, through the technological openings of which air flows enter the device.

Suction devices are classified according to the shape of the hole in the device, which can be round, square or made in the form of a slit. Round and square holes are most often used in metal welding and soldering processes. Ventilation during welding cannot always neutralize all harmful air flows, so a forced general ventilation system must be installed in the welding shop, with a fresh air flow 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 a large number of types and methods of welding. It is their diversity that has led to the variety of suction options used specifically in welding shops. Based on their design features, they can be divided into 4 main groups:

1. Small-sized devices for automatic and semi-automatic equipment. Such ventilation devices are integrated into welding equipment. These include air intakes in welding holders.
2. Local suction built into welding tables. These devices are used for welding and soldering small parts. Local ventilation for soldering and welding can be connected to the general ventilation system.
3. 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.
4. Rotary lift and portable contaminant removal tools for welding applications in a variety of locations. This group of devices includes all portable air receivers of various designs.

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

Factors influencing the calculation of ventilation in welding production

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

This publication will provide general information about what affects ventilation calculations for a production site with a permanent welding station.

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

• The required air flow rate of the air intake device, depending on its design and type of welding.
• Its effectiveness in a specific workplace.

To calculate air flow, you can use the formula:

L = 3600 * F * Vo

Where:

L— air exchange
F is the area of ​​the suction opening
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 vehicle 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 at the rate of: 3300 m3/hour per 1 m2 of panel area.

The efficiency of the device is calculated using the formula:

E = (Lm — Lpr) / Lm

Where

E— device efficiency
Lm- the power that will be required by the in-shop ventilation system, in the absence of a local air intake
Lpr- air flow required to dilute non-localized contaminants to maximum permissible concentrations.

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

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

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 purified, heated or cooled, meeting all standards.

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

• presence of harmful fumes
• change in temperature
• increased gas pollution

Solution

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

1. Techniques, production parameters
2. Required working conditions

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

Ventilation price (online calculation)

Type of premises/building:

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

Equipment class:

Economy Average Premium

Total area of ​​all serviced premises:

m 2

Average floor height:

m

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

people

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Air exchange rate

The optimal frequency of air exchange in industrial premises is determined based on reference tables SNiP 2.04.05-91 and is within 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. The standards also establish the minimum permissible volume of incoming fresh air. Let's take a closer look at 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 through the room depend on the shape; turbulence and stagnant zones may occur.
• Number of employees working in the workshop. The required supply 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 frequency are dyeing 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.
• Heat generated by equipment. Excess heat energy must also be effectively removed by the ventilation system, especially if the room is not air conditioned.
• 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 in temporary workplaces;

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

The air temperature of the working area at industrial facilities with fully automated production lines operating without maintenance personnel is allowed: in the summer at the level of the air temperature outside, with excess heat - 4 ° C more than the outside air temperature; in winter - in the absence of excess heat - 10°C, in the presence of excess heat - an economically justified level.

Requirements for industrial ventilation

Ventilation and air conditioning of production premises is regulated by the general requirements of SanPiN, as well as parameters specific to the particular workshop of the enterprise. These include:

• mechanical ventilation of industrial premises must comply with fire safety rules;
• removal of substances hazardous to health and emissions without allowing personnel into the work area;
• a hygienic and fire safety certificate is required for 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 flammable paint should not exceed 0.2 mm;
• for personnel work areas located directly inside the workshop, the concentration of harmful substances should not be more than 30%;
• Humidity and air flow speed indicators are not standardized in the summer;
• in winter, the air temperature inside the workshop with personnel located there is at least 10⁰ C, in the absence of people - at least 5⁰ C;
• 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 C;
• workshops that are not used in the summer do not regulate the requirements for industrial ventilation in terms of temperature;
• the overall noise level inside an industrial workshop 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 production parameters, workshop design, specifics of the products, etc. In addition, it is necessary to take into account how heating and ventilation interact inside the workshop. 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 method of operation. Let's take a closer look.

According to the principle of operation

• Natural. It is based on the natural circulation of air flows with different temperatures, pressures, and densities. Heavy cold air flow displaces lighter and warmer air. In an industrial building, this process can occur through natural gaps, leaks in window and door openings, or organized supply and exhaust openings covered with grilles and deflectors.
  Depends on atmospheric conditions, wind strength and direction, time of year (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. Can be installed, for example, in agricultural premises.

• Artificial ventilation. If production involves a side effect in the form of toxic heat and gas emissions, mechanical ventilation of production premises is strictly required. The main function is to remove the exhaust air flow from the personnel work area, prevent the penetration of harmful vapors into other rooms, compartments, as well as supply fresh street air (purified or unpurified) in a general flow or targeted.
  It is organized using mechanical means of supplying and removing air masses (supply and exhaust fans, roof units). It is a more effective way to clean and circulate air flow inside an industrial workshop.

According to the principle of localization

• General exchange. Designed to uniformly clean the entire workshop from harmful technological heat emissions, normalizing temperature and humidity levels and air movement speed. Quickly copes with a small percentage of air pollution.
• Local ventilation. It is used when there is localization of a large amount of toxins, vapors, smoke, etc. in a certain place. Installed directly above the source of increased heat and gas generation. Exhaust hoods or flexible ducting connected directly to the equipment may be used. Used in conjunction with a general ventilation system as additional air purifying equipment.
• Emergency. It is installed and used in the future in case of emergency, for example, fire, excessive release of toxic substances from industrial equipment, high levels of smoke, etc.

Based on 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 either natural or mechanical.
• Exhaust ventilation units remove waste air flow along with particles of burning, smoke, toxic fumes, excess heat, etc. Structurally, they can be general or local, most often with forced motivation, since it is quite problematic to remove polluted air naturally.
• Supply and exhaust unit used most often, it ensures the necessary circulation of air masses inside the industrial workshop. Most often with mechanical equipment (supply and exhaust fans).

Equipment for ventilation of industrial premises

The forced supply ventilation system consists of the following elements:

• air ducts;
• fan;
• air filters;
• air valves;
• air intake grilles;
• sound-absorbing insulation;
• 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 and filters, which are not needed for the removed air.

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

In addition, supply and exhaust ventilation can be equipped with a heat recuperator to save energy when heating the incoming flow. The supply masses are heated by the heat of the removed 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 and correctly design exhaust zones.

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

As is known, general exchange and local ventilation are used for industrial premises. The first is responsible for air exchange and air purification of the entire room. But with the help of local suction, only local problems can be solved at the place of formation of those same harmful substances. But it is not possible to contain and neutralize such air flows completely, preventing their spread throughout the room. Additional elements are needed here, such as umbrellas.

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

To summarize, I would like to say that such a difficult task as calculation, design and subsequent installation of ventilation should be performed by qualified specialists who have a wealth of knowledge and years of experience.

Ventilation systems control

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

Ventilation systems are one of the main consumers of electrical and thermal energy, therefore the introduction of energy saving measures makes it possible to reduce the cost of manufactured products. The most effective measures include the use air recovery systems, air recirculation and electric motors with no “dead zones”.

The recovery principle is based on the transfer of heat from the displaced air to a heat exchanger, resulting in reduced heating costs. The most widespread are plate and rotary type recuperators, 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, some air from outside is mixed into it. This technology is used in the cold season 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, pathogenic microorganisms, 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 .

Considering 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 startup, when the fan is running in idle mode, or when the network resistance is significantly less than what is required for its correct operation. In order to avoid this phenomenon, motors are used with the ability to smoothly regulate speed and with the absence of starting currents, which allows saving energy when starting and during operation.

Example of air exchange calculation

The main purpose of exhaust ventilation is to remove exhaust air from the serviced premises. Exhaust ventilation, as a rule, works in conjunction with supply ventilation, which, in turn, is responsible for supplying clean air.

In order to have a favorable and healthy microclimate in the room, you need to draw up a competent design of the air exchange system, perform the appropriate calculations and install the necessary units according to all the rules. When planning, you need to remember that the condition of the entire building and the health of the people who are in it depend on it.

The slightest mistakes lead to the fact that ventilation ceases to cope with its function as it should, fungus appears in the rooms, finishing and building materials are destroyed, and people begin to get sick. Therefore, the importance of correct calculation of ventilation should not be underestimated in any case.

Main parameters of exhaust ventilation

Depending on what functions the ventilation system performs, existing installations are usually divided into:

1. Exhaust. Necessary for the intake of exhaust air and its removal from the room.
2. Inlet. Provides fresh, clean air from the street.
3. Supply and exhaust. At the same time, old musty air is removed and new air is introduced into the room.

Exhaust units are mainly used in production, offices, warehouses and other similar premises. The disadvantage of exhaust ventilation is that without a simultaneous installation of a supply system, it will work very poorly.

If more air is drawn out of a room than is supplied, drafts will form. Therefore, the supply and exhaust system is the most effective. It provides the most comfortable conditions both in residential premises and in industrial and working areas.

Modern systems are equipped with various additional devices that purify the air, heat or cool it, humidify it and distribute it evenly throughout the premises. The old air is removed through the hood without any difficulty.

Before you begin arranging a ventilation system, you need to take the process of calculating it very seriously. The ventilation calculation itself is aimed at determining the main parameters of the main components of the system. Only by determining the most suitable characteristics can you make ventilation that will fully fulfill all its tasks.

During the ventilation calculation, the following parameters are determined:

1. Consumption.
2. Operating pressure.
3. Heater power.
4. Cross-sectional area of ​​air ducts.

If desired, you can additionally calculate the energy consumption for operation and maintenance of the system.

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Step-by-step instructions for determining system performance

The calculation of ventilation begins with determining its main parameter - productivity. The dimensional unit of ventilation performance is m³/h. In order for the air flow calculation to be performed correctly, you need to know the following information:

1. The height of the premises and their area.
2. The main purpose of each room.
3. The average number of people who will be in the room at the same time.

To make the calculation, you will need the following equipment:

1. Tape measure for measurements.
2. Paper and pencil for notes.
3. Calculator for calculations.

To perform the calculation, you need to find out such a parameter as the rate of air exchange per unit of time. This value is set by SNiP in accordance with the type of room. For residential, industrial and administrative premises the parameter will vary. You also need to take into account such points as the number of heating devices and their power, the average number of people.

For domestic premises, the air exchange rate used in the calculation process is 1. When calculating ventilation for administrative premises, use an air exchange value of 2-3 - depending on the specific conditions. The frequency of air exchange directly indicates that, for example, in a domestic room the air will be completely renewed once every 1 hour, which is more than enough in most cases.

Calculation of productivity requires the availability of data such as the amount of air exchange by multiplicity and the number of people. It will be necessary to take the largest value and, starting from it, select the appropriate exhaust ventilation power. The air exchange rate is calculated using a simple formula. It is enough to multiply the area of ​​the room by the ceiling height and the multiplicity value (1 for household, 2 for administrative, etc.).

To calculate air exchange by number of people, multiply the amount of air consumed by 1 person by the number of people in the room. As for the volume of air consumed, on average, with minimal physical activity, 1 person consumes 20 m³/h, with average activity this figure rises to 40 m³/h, and with high activity it is already 60 m³/h.

To make it clearer, we can give an example of a calculation for an ordinary bedroom with an area of ​​14 m². There are 2 people in the bedroom. The ceiling has a height of 2.5 m. Quite standard conditions for a simple city apartment. In the first case, the calculation will show that the air exchange is 14x2.5x1=35 m³/h. When performing the calculation according to the second scheme, you will see that it is already equal to 2x20 = 40 m³/h. It is necessary, as already noted, to take a larger value. Therefore, specifically in this example, the calculation will be performed based on the number of people.

Using the same formulas, oxygen consumption is calculated for all other rooms. In conclusion, all that remains is to add up all the values, obtain the overall performance and select ventilation equipment based on these data.

Standard performance values ​​for ventilation systems are:

1. From 100 to 500 m³/h for ordinary residential apartments.
2. From 1000 to 2000 m³/h for private houses.
3. From 1000 to 10000 m³/h for industrial premises.

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Determining the power of the air heater

In order for the calculation of the ventilation system to be carried out in accordance with all the rules, it is necessary to take into account the power of the air heater. This is done if supply ventilation is organized in combination with exhaust ventilation. A heater is installed so that the air coming from the street is heated and enters the room already warm. Relevant in cold weather.

The calculation of the power of the air heater is determined taking into account such values ​​as air flow, the required outlet temperature and the minimum temperature of incoming air. The last 2 values ​​are approved in SNiP. In accordance with this regulatory document, the air temperature at the heater outlet must be at least 18°. The minimum outside air temperature should be specified in accordance with the region of residence.

Modern ventilation systems include performance regulators. Such devices are designed specifically to reduce the speed of air circulation. In cold weather, this will reduce the amount of energy consumed by the air heater.

To determine the temperature at which the device can heat the air, a simple formula is used. According to it, you need to take the power value of the unit, divide it by the air flow, and then multiply the resulting value by 2.98.

For example, if the air flow at the facility is 200 m³/h, and the heater has a power of 3 kW, then by substituting these values ​​into the above formula, you will get that the device will heat the air by a maximum of 44°. That is, if in winter it is -20° outside, then the selected air heater will be able to heat the oxygen to 44-20 = 24°.

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Operating pressure and duct cross-section

Calculation of ventilation involves the mandatory determination of such parameters as operating pressure and cross-section of air ducts. An efficient and complete system includes air distributors, air ducts and fittings. When determining working pressure, the following indicators must be taken into account:

1. The shape of ventilation pipes and their cross-section.
2. Fan parameters.
3. Number of transitions.

Calculation of the appropriate diameter can be done using the following relationships:

1. For a residential building, a pipe with a cross-sectional area of ​​5.4 cm² will be sufficient for 1 m of space.
2. For private garages - a pipe with a cross-section of 17.6 cm² per 1 m² of area.

A parameter such as air flow speed is directly related to the cross-section of the pipe: in most cases, the speed is selected within the range of 2.4-4.2 m/s.

Thus, when calculating ventilation, be it an exhaust, supply or supply and exhaust system, you need to take into account a number of important parameters. The effectiveness of the entire system depends on the correctness of this stage, so be careful and patient. If desired, you can additionally determine the energy consumption for the operation of the system being installed.

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

Mission and functions

The design and installation of industrial ventilation solves several problems, the main one of which is 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, they design the ventilation system.

It is almost impossible to accurately determine the required data. The erudition and experience of specialists: technologists, designers, engineers plays a lot here. 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 ventilation of industrial premises necessary?

Its main function is to provide comfortable living conditions for the employees of this production workshop. In addition, thanks to proper ventilation, the necessary technological processes and storage requirements for a particular type of product are ensured.

It is with the help of ventilation systems that optimal conditions are created at enterprises, in accordance with sanitary standards. They not only increase production efficiency and worker productivity, but also improve the quality of manufactured products, reducing the defect rate.

During the ventilation process, dust particles and excess moisture are removed from the air in the production room, and the optimal temperature is established. The air is cleaned of flammable, explosive and simply harmful substances to human health.

Harmful substances released during production

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

Industrial ventilation solves the problem of excessive dust in premises, when dust particles are released into the air in quantities exceeding the maximum permissible values. The same applies to smoke particles and aerosol substances. Finally, during the production process, tiny particles of liquid are concentrated in the air in the form of mist or hollow droplets of gas bubbles.

All these “harmful things” are carried by air. And the ventilation system determines the required air flow, forming temperature fields. It constantly removes polluted air from outside and pumps in clean, cool air from outside. This air exchange is carried out using special exhaust equipment.

Design and calculation of ventilation

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

• The area of ​​the production premises, its dimensions and height;
• Design features and architectural nuances;
• Purpose of the industrial facility;
• Size and type of installations that emit harmful substances into the air;
• The number of workers constantly present in the premises and the duration of their stay;
• Location of workplaces;
• The number of units of equipment and its level of workload, as well as much more.

Industrial and other large cities are organized taking into account certain requirements. For example, a small room with an area of ​​less than 20 square meters must 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. An exhaust hood, or industrial exhaust ventilation, is responsible for removing dirty air, and supply air is responsible for supplying clean air. They can work either simultaneously or chaotically. However, the amount of injected and exhausted air 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 indoors, due to different pressures and the action of winds. Mechanical ventilation, accordingly, works due to installed fans.

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

Forced ventilation

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

General ventilation

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

Local ventilation

Serves to create specific parameters in a clearly defined room. Technically, it is implemented using special structures, including:

• air curtain - a flat air stream that prevents harmful substances from entering a certain area from the air;
• air shower - a directed stream of air, for example, at an industrial installation or at 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 suction.

In enterprises with increased dust and gas emissions, it is not recommended to install a general ventilation system. In this case, the more powerful the equipment, the more harmful substances will be spread throughout the production area.

What types of industrial fans are there?

Today there are different types of fans. Here are the main ones.

• Axial. The most common type 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 industrial enterprises. Also used in the ventilation system of residential complexes.
• Duct. Often used in offices, mounted under suspended ceilings or in air duct networks, directly in the ventilation duct.

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

• Soundproofed. They are installed in rooms where even 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 from particularly durable materials and coated with special fire-resistant paint.
• Explosion resistant. They are used in enterprises whose activities involve the production of explosive gases. They are made from a special silumin material, which is corrosion-resistant and especially durable.
• Resistant to aggressive environments. Indispensable in chemical plants or laboratories where chemically aggressive substances are present in a gaseous state.
• To remove smoke. Such fans can often be seen in emergency ventilation systems. They do an excellent job of removing polluted air and reducing smoke during fires.

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

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