Exhaust system for industrial premises. Local exhaust ventilation: features and calculations for a production workshop. Promising directions for industrial hoods
Work in factories and other manufacturing enterprises often involves the use of substances harmful to humans, the formation of toxic fumes, and unpleasant odors. All this is dangerous to the life and health of workers, so in such premises a ventilation system must be installed that will provide air exchange at the required intensity and create comfortable working conditions for people.
Even if only one person is required, ventilation requirements for production areas must be met. For industrial premises, microclimate requirements are established depending on the category of work. Below is a table of standard parameters in accordance with SNiP 41-01-2003.
Types of industrial ventilation
There are several features by which several types of ventilation of industrial premises can be distinguished.
According to the operating principle- natural and mechanical.
Natural ventilation occurs due to the temperature difference between different air flows or due to the special arrangement of windows in the room. But this system is not very efficient, so in emission-related industries harmful substances, used mechanical ventilation. It not only purifies the air, but also prevents harmful fumes from entering work areas and guarantees the safety of workers.
On the organization of air exchange- for general exchange and local.
General exchange Ventilation of industrial premises creates uniform air exchange, while all parameters: temperature, humidity, air speed become the same at any point in the room. This system allows you to quickly get rid of small dirt.
If a lot of harmful substances and fumes are released in a certain place, then local ventilation simply necessary. It is designed to purify a small volume of air and is located next to the device that pollutes the air. It can be combined with general ventilation to achieve better results. Local exhaust is accomplished either by an exhaust hood installed directly above the equipment or by a flexible duct connected to the exhaust vent on the equipment.
Local exhaust through an exhaust hood Local exhaust from equipment
If harmful substances are released at several points in the room, then it will be much more effective to work more efficiently. local system ventilation. It is an exhaust hood, mounted in close proximity to the source of emissions.
In order to calculate the power of the exhaust device, you need to know the size of the emission source, as well as its technological characteristics: electrical/thermal power, concentration of emitted harmful substances, etc. The dimensions of the umbrella must exceed the dimensions of the emission source by 10 - 20 cm on each side.
By device type- for supply, exhaust and supply and exhaust.
In enterprises, it is the latter type that is most often used: it is a combination of the functions of exhaust and supply ventilation of industrial premises, that is, it ensures complete air exchange, and not just the removal of contaminated air masses or supply of clean air.
- Exhaust ventilation of industrial premises forcibly removes air from the room; there is no organized air flow. The system only provides air exhaust and removal of contaminants, and air supply occurs through cracks, vents, and doors.
- WITH supply systems this principle works exactly the opposite: the air supplied from outside causes too much pressure in the room and the excess air itself is removed through the same gaps in the walls, door and window openings.
Both of these systems are ineffective, and for production processes in which hazardous substances are released, they cannot be used, because there is a high probability that harmful air will enter the work area. In addition, to organize a working exhaust system in production, it will be necessary to use large equipment electrical power, because they will be subject to serious loads. You will also need to organize a distribution duct system.
Calculation of ventilation of production premises
When calculating the ventilation of an industrial premises, it is necessary to determine what type of system is required: general exchange or local.
The general exchange system is calculated using the following formulas:
L = l * n, Where
L - required consumption air per room
n- number of people in the room
l - specific consumption air per person (in accordance with SNiP 41-01-2003).
This calculation formula applies to industries that do not emit harmful substances. Otherwise, the calculation of ventilation of production premises will be made for each type of substance as follows:
L = Lm.v. + (mv.v. - Lm.v. (Su.v. - Sp.v.))/(C1 - Sp.v.)
L m.v.- air consumption removed by local hoods, m 3 /h;
m i.v.- harmful substances entering the room from outside, mg/h;
C u.v.- concentration of harmful substances in the removed air, mg/m3;
C p.v.- concentration of harmful substances in the supply air, mg/m3;
C 1- required concentration of harmful substances in the room, mg/m 3 ;
If during the operation of an object not one, but several harmful substances are released, then the volume of air exchange is calculated for each of them using the above formula, and then the resulting values are summed up.
Design and installation of a ventilation system in production
There are several stages in planning and installing ventilation in production:
- Preparation and approval terms of reference for ventilation design (contains technological characteristics of equipment, air exchange requirements, etc.)
- Design stage. An aerodynamic calculation of the system is performed to determine the dimensions of the air ducts and the characteristics of the equipment. Ventilation units and additional components are selected for balancing and adjusting the system. The ventilation control system is selected. It is at the project stage that the system can be made energy efficient and therefore not expensive to maintain.
- Purchase and supply of materials and equipment. Carried out according to a previously prepared specification, after agreement with the Customer.
- Installation work. Installation is one of the most critical stages in the entire project. Installation must be carried out by qualified specialists, otherwise the system may not only fail to meet project costs, but may even fail altogether.
- Commissioning Any ventilation system has a start-up and control system. Also, to reach the design capacity, the air duct system needs to be balanced.
System design involves not only calculation, but also distribution of the main components of the system on the diagram.
Requirements for ventilation in industrial premises
According to SNiP 41-01-2003 production premises the following conditions must be taken into account:
- The noise level from equipment, including ventilation, should not exceed 110 dBA.
- The system must not be explosive.
- Ventilation must remove harmful substances without entering the work area.
- Devices must be repairable.
- The system equipment must undergo hygienic and fire certification, confirming that they are made from materials safe for humans.
- Air ducts that remove vapors harmful to humans or explosive can be crossed by pipelines with a coolant only if the temperature of the latter is more than 20 °C below the ignition temperature of the substance.
- Ducts must be covered or made from materials that are resistant to corrosion. If the passage is painted with flammable paint, the coating should not exceed 0.2 mm in thickness.
- During the cold season, the temperature of the production room should not fall below 5 °C if it is non-working time, and not below 10 °C if there are people in the room.
- IN warm time year, the temperature in production premises is not standardized if they are not used for their intended purpose or during non-working hours.
- In the warm season, the normal temperature in production premises is equal to the air temperature outside. If it is higher in production, then it should be lowered so that it does not exceed the street temperature by more than 4 °C. However, it is worth considering that it should not fall below 29 °C.
- Air humidity and the speed of its movement in the warm season are not standardized.
- For industries in which harmful substances are released, the MAC (maximum permissible concentration) standards must be observed. For work areas located directly at production concentration hazardous substances should not be more than 30% of the maximum permissible concentration.
All these requirements are necessary, but not always sufficient for a fully-quality technological process and comfortable working conditions for people.
In addition to the general SNiP requirements, each type of production also has a number of its own requirements, and there are many of them.
More details about the ventilation of some types of production workshops can be found in the corresponding article “Ventilation of the workshop”.
In conclusion, I would like to note that serious industrial ventilation of production facilities is a very delicate and difficult to calculate process. Don't neglect general rules when selecting a system, and of course, we recommend that you contact specialists with such tasks.
The air environment inside industrial buildings is polluted much more intensively than in apartments and private houses. The types and amounts of harmful emissions depend on many factors - the industry of production, the type of raw materials, the technological equipment used, and so on. It is quite difficult to calculate and design ventilation of industrial premises that removes all harmful substances. We will try to present in accessible language the calculation methods prescribed in the regulatory documents.
Design algorithm
The organization of air exchange inside a public building or in production is carried out in several stages:
- Collection of initial data - characteristics of the structure, number of workers and severity of labor, types and quantities of hazardous substances generated, localization of release points. It is very useful to understand the essence of the technological process.
- Selecting a ventilation system for a workshop or office, developing diagrams. TO design solutions 3 main requirements are put forward - efficiency, compliance with SNiP (SanPin) standards and economic feasibility.
- Calculation of air exchange – determination of the volume of supply and exhaust air for each room.
- Aerodynamic calculation of air ducts (if any), selection and placement of ventilation equipment. Clarification of supply and removal schemes for contaminated air.
- Installation of ventilation according to the project, launch, further exploitation and service.
Note. For a better understanding of the process, the list of works is greatly simplified. At all stages of documentation development, various approvals, clarifications and additional examinations are required. The design engineer constantly works in conjunction with the enterprise's technologists.
We are interested in points No. 2 and 3 - choosing the optimal air exchange scheme and determining air flow rates. Aerodynamics, installation of ventilation ducts and equipment are extensive topics in other publications.
Types of ventilation systems
To properly organize the renewal of the indoor air environment, you need to choose the optimal ventilation method or a combination of several options. Below on structural diagram The classification of existing ventilation systems installed in production is shown in a simplified manner.
Let us explain each type of air exchange in more detail:
- To the disorganized natural ventilation This includes ventilation and infiltration - the penetration of air through door frames and other cracks. Organized supply - aeration - is carried out from windows using exhaust deflectors and skylights.
- Auxiliary roof and ceiling fans increase the intensity of exchange during the natural movement of air masses.
- The mechanical system involves the forced distribution and extraction of air by fans through air ducts. This also includes emergency ventilation and various local suction systems - umbrellas, panels, shelters, laboratory fume hoods.
- Air conditioning – bringing the air environment of a workshop or office to the required condition. Before being supplied to the work area, the air is purified by filters, / dehumidified, heated or.
Air heating/cooling using heat exchangers - air heaters Reference. According to regulatory documentation, the serviced (working) area includes the lower part of the workshop volume, 2 meters high from the floor, where people are constantly present.
Mechanical supply ventilation is often combined with air ventilation - in winter the street flow heats up to optimal temperature, water radiators are not installed. Contaminated hot air is sent to the recuperator, where it transfers 50-70% of the heat to the influent.
Achieve maximum efficiency A combination of the above options allows work at a reasonable price of equipment. Example: in a welding shop, it is allowed to design natural aeration, provided that each station is equipped with forced local exhaust.
Scheme of flow movement during natural aeration Direct instructions for the development of air exchange schemes are given by sanitary and industry standards; there is no need to invent or invent anything. Documents have been developed separately for public buildings and various industries– metallurgical, chemical, enterprises Catering and so on.
Example. When developing ventilation for a hot welding shop, we find the document “ Sanitary rules when welding, surfacing and cutting metals,” read section 3, paragraphs 41-60. It sets out all the requirements for local and general ventilation depending on the number of workers and material consumption.
Supply and exhaust ventilation industrial premises are selected depending on the purpose, economic feasibility and according to current regulations:
- In office buildings, it is customary to provide natural air exchange - aeration, ventilation. In case of increased crowding of people, it is planned to install auxiliary fans or organize air exchange with mechanical stimulation.
- In machine-building, repair and rolling shops large sizes it would be too expensive to arrange forced ventilation. The generally accepted scheme: natural exhaust through skylights or deflectors, the inflow is organized from openable transoms. Moreover, in winter the upper windows open (height - 4 m), in summer – the lower ones.
- If toxic, hazardous and harmful vapors are released, aeration and ventilation are not allowed.
- In workplaces near heated equipment, it is easier and more correct to organize the showering of people with fresh air than to constantly update the entire volume of the workshop.
- In small industries with a small number of sources of pollution, it is better to install local suction in the form of umbrellas or panels, and provide general ventilation with natural ventilation.
- In production buildings with a large number of workplaces and sources of harmful emissions, it is necessary to use powerful forced air exchange. It is not advisable to fence 50 or more local hoods, unless such measures are dictated by regulations.
- In laboratories and work areas of chemical plants, all ventilation is mechanical, and recirculation is prohibited.
General exchange project forced ventilation three-story building with central air conditioning (longitudinal section) Note. Recirculation is the return of part of the selected air back to the workshop in order to save heat (in summer - cold) spent on heating. After filtering, this part is mixed with fresh street flow in various proportions.
Since it is unrealistic to consider all types of production within the framework of one publication, we have outlined general principles air exchange planning. A more detailed description is provided in the relevant technical literature, e.g. tutorial O. D. Volkova “Design of ventilation for an industrial building.” The second reliable source is the ABOK engineers forum (http://forum.abok.ru).
Methods for calculating air exchange
The purpose of the calculations is to determine the flow rate of the supplied supply air. If point hoods are used in production, then the amount of air mixture removed by the umbrellas is added to the resulting volume of inflow.
For reference. Exhaust devices have very little effect on the movement of flows inside the building. Inflow jets help inform them in the right direction.
According to SNiP, calculation of ventilation of production premises is done according to the following indicators:
- excess heat emanating from heated equipment and products;
- water vapor saturating the workshop air;
- harmful (toxic) emissions in the form of gases, dust and aerosols;
- number of employees of the enterprise.
Important point. In utility rooms and various household rooms normative base also provides for calculation based on the frequency of exchange. You can familiarize yourself with the methodology and use the online calculator.
An example of a local suction system operating from one fan. Dust collection is provided with a scrubber and an additional filter Ideally, the inflow flow rate is calculated according to all indicators. The largest of the obtained results is accepted for subsequent development of the system. One caveat: if 2 types of dangerous gases are released that interact with each other, the influx is calculated for each of them, and the results are summed up.
We calculate the consumption by heat releases
Before starting calculations, you need to carry out preparatory work to collect initial data:
- find out the areas of all hot surfaces;
- find out the heating temperature;
- calculate the amount of heat released;
- determine the air temperature in the work area and outside it (above 2 m above the floors).
In practice, the problem is solved jointly with the enterprise’s process engineer, who provides information about production equipment, product characteristics and the intricacies of the manufacturing process. Knowing the specified parameters, perform the calculation using the formula:
Explanation of symbols:
L – the required volume of air supplied air supply units or penetrating through transoms, m³/h;
- Lwz – amount of air taken from the serviced area by point suction, m³/h;
- Q – amount of heat release, W;
- c – heat capacity of the air mixture, taken equal to 1.006 kJ/(kg °C);
- Tin – temperature of the mixture supplied to the workshop;
- Tl, Twz – air temperatures above the working zone and within it.
The calculation seems cumbersome, but if you have the data, it can be done without problems. Example: indoor heat flow Q is 20,000 W, exhaust panels remove 2,000 m³/h (Lwz), outdoor temperature is + 20 °C, inside – plus 30 and 25, respectively. We consider: L = 2000 + = 8157 m³/h.
Excess water vapor
The following formula practically repeats the previous one, only the heat parameters are replaced by humidity symbols:
- W – the amount of water vapor coming from sources per unit of time, grams/hour;
- Din – moisture content in the inflow, g/kg;
- Dwz, Dl – moisture content of the air in the working area and the upper part of the room, respectively;
- the remaining designations are as in the previous formula.
The complexity of the technique lies in obtaining the initial data. When the facility is built and production is running, humidity indicators are not difficult to determine. Another question is to calculate the vapor emissions inside the workshop at the design stage. The development should be carried out by 2 specialists - a process engineer and a ventilation system designer.
Emissions of dust and harmful substances
In this case, it is important to thoroughly study the intricacies of the technological process. The task is to compile a list of harmful substances, determine their concentration and calculate the flow rate of supplied clean air. Calculation formula:
- Mpo – mass of harmful substance or dust released per unit of time, mg/hour;
- Qin – content of this substance in street air, mg/m³;
- Qwz – extremely permissible concentration(MPC) harmfulness in the volume of the serviced area, mg/m³;
- Ql is the concentration of aerosol or dust in the remaining part of the workshop;
- the decoding of the designations L and Lwz is given in the first formula.
The ventilation operation algorithm is as follows. A calculated amount of inflow is directed into the room, diluting the internal air and reducing the concentration of pollutants. The lion's share of harmful and volatile substances local umbrellas located above the sources are drawn in, the mixture of gases is removed by mechanical exhaust.
Number of working people
The methodology is used to calculate the inflow into office and other public buildings where there are no industrial pollutants. You need to find out the number of permanent jobs (denoted by the Latin letter N) and use the formula:
Parameter m shows the volume of clean air mixture allocated per 1 workplace. In ventilated offices, the value of m is taken to be 30 m³/h, completely closed - 60 m³/h.
Comment. Only permanent workplaces where employees stay for at least 2 hours a day are taken into account. The number of visitors does not matter.
Calculation of local exhaust hood
The purpose of local suction is to remove harmful gas and dust at the extraction stage, directly from the source. To achieve maximum efficiency, you need to choose the right umbrella size depending on the dimensions of the source and the height of the suspension. It is more convenient to consider the calculation method in relation to the suction drawing.
Let's decipher letter designations on the diagram:
- A, B – the required dimensions of the umbrella in plan;
- h – distance from the lower edge of the retractor to the surface of the ejection source;
- a, b – dimensions of the equipment to be covered;
- D – diameter of the ventilation duct;
- H – suspension height, assumed to be no more than 1.8…2 m;
- α (alpha) – the opening angle of the umbrella, ideally does not exceed 60°.
First of all, we calculate the dimensions of the suction in plan using simple formulas:
- F – area of the wide part of the umbrella, calculated as A x B;
- ʋ — air flow speed in the duct, for non-toxic gases and dust we take 0.15...0.25 m/s.
Note. If it is necessary to suck out toxic pollutants, standards require increasing the exhaust flow speed to 0.75...1.05 m/s.
Knowing the amount of air taken, it is not difficult to select duct fan required performance. The cross-section and diameter of the exhaust air duct is determined by the inverse formula:
Conclusion
Designing ventilation networks is the task of experienced engineers. Therefore, our publication is for informational purposes only; the explanations and calculation algorithms are somewhat simplified. If you want to thoroughly understand the issues of ventilation of premises in production, we recommend that you study the relevant technical literature, there is no other way. Finally, the calculation method air heating as part of the video.
An industrial hood is designed to create air circulation inside industrial premises in order to remove harmful substances and gases. Refers to industrial equipment installations. This is especially true in ventilation systems at heavy and chemical industrial enterprises.
The main unpleasant factors that a hood can remove are harmful substances, production waste, unpleasant odors, tobacco smoke and street smog. Main elements of the hood:
- Air ducts.
- Electric motors.
- A set of fans in air ducts.
- Cleaning filters.
Ventilation of industrial premises is divided:
- Hanging. All elements of such a system, as a rule, are located under the ceiling of the room, without cluttering the work area production process. But this requires high-altitude installation of the components of such a system, and thereby attracting more qualified personnel for the work, with permission to work at height.
- Built-in. In some cases, hood elements can be installed into the design of the plant and workshop facilities. This will save some space in the room, but will require the development of additional technical documentation(plan, design features) such an installation.
- Wall-mounted. This is perhaps the most common installation scheme for ventilation of industrial premises, because... does not require a special approach to installation. This arrangement of the hood elements reduces the labor intensity of servicing the ventilation system.
- Island. This type of installation involves installing the components of the hood, and most importantly, the air intake in a certain place in the production room. As a rule, such a place is the source of maximum emissions of harmful substances and gases in large workshops.
- Angular. Basically, equipment and machines are mounted in the central part of the room, for maximum access to them during work. Thus, the corners of the workshop remain unused. Therefore, such places become attractive for installation where additional equipment is needed, in the form of local exhaust ventilation.
According to the principle of operation, production exhaust ventilation systems are divided into various types: continuous (natural) and forced. First exhaust system production ventilation is used if the level of pollution in the room is not so high. At its core, flow hood uses the movement of air mass from the workshop to the outside, due to the difference in temperature and pressure in the room and outside it. This excludes the use of electric motors and fans from the circuit, which makes it possible not to use electricity during its operation. But if emissions of harmful substances in industrial premises are massive, then without compulsory system local exhaust ventilation is indispensable.
Its design includes electric motors connected to fans, which make it possible to “suck” significant volumes of air from the room, which in turn leads to a significant cleansing of the “atmosphere” of the workshop from pollution. Filters are often installed in the forced exhaust system to help solve the problem of contamination environment. Ventilation air exchange in production includes two pipelines: suction and exhaust. A fan unit with an electric motor is installed between them, creating forced air circulation. The presence of an additional gas analyzer element allows you to significantly save energy. Its purpose is to control the content of harmful substances in the workshop. Depending on their concentration, the analyzer controls the engine speed. That is, when there is a lot of gas pollution, it increases the speed, and therefore the volume of air space pumped out from the room. If the content of harmful substances in the “atmosphere” of the workshop is low, he switches the engine to low speeds or turns it off altogether.
As a rule, along with exhaust from the room, supply is also used. fresh air from the street. Such a system is called circulation. This, in turn, allows you to better clean the room and “saturate” it with fresh air.
There are two types of exhaust fans: radial and centrifugal. Air speed in radial fans higher than in centrifugal ones. This is due to the fact that the air mass in them moves in a straight direction. In turn, this scheme ensures faster movement of air flows, therefore, more “high-speed” air exchange.
Snail hood
Perhaps the most common design for an exhaust ventilation unit in industrial workshops is a snail hood. Its design differs significantly from centrifugal fans.
This model is characterized by ease of manufacture and installation in the workshop. Its main element is the frame on which the electric motor is mounted. A round fan box is mounted to the engine mounting flanges. A centrifugal fan in a sound-insulated casing, connected to the electric motor shaft, is placed through a central hole in the box inside. Due to the special angle of installation of the blades on the fan air duct wheel, when it rotates, a vacuum is created in the cavity behind it. This ensures a constant flow of air to the exhaust unit and its movement further in the outlet pipeline.
The number of blades, their sizes and compaction at the points of contact between the low and high pressure determines the flow rate. The wheel diameter can vary from 25 to 150 cm, depending on the volume of pumped air.
Snail hoods are divided into three classes:
- Low pressure (P-100 kg/m²). They are used, as a rule, in domestic conditions and small workshops.
- Medium pressure (P-from 100 to 300 kg/m²). The devices are used in production workshops with low gas contamination.
- High pressure (P- more than 300 kg/m²). They are used in particularly polluted places, be it paint shops or areas of metallurgical plants with a high concentration of harmful substances.
Depending on the environment with which the blades will come into contact, they are made heat- and corrosion-resistant.
Calculation of supply and exhaust ventilation
Before you start calculating the basic parameters of the hood, you need to decide on the source of harmful, flammable or explosive substances. But calculations are usually based on required amount fresh air for one person. In this case, the calculation of the general exchange air concentration is determined as follows:
Amount of air: L=N × m, where N is the number of people working in the room, and m is the specific air flow per person per hour.
According to SNiP standards, the value of m is: 30 m³/h for ventilated rooms and 60 m³/h for unventilated ones.
If, however, substances that are not only harmful, but also dangerous to human life are released into the “atmosphere” of the workshop, then the calculation is carried out according to the maximum permissible concentration (MPC). The MAC norm for a specific substance is taken from special reference books and is strictly regulated by high requirements. In this case, the volume must be calculated:
Amount of air during hazardous emissions: L=Mv/ (inc. -p), where Mv is the mass of the substance released into the air (mg/h); pm - specific concentration of this substance in the workshop space (mg/m³); unit is the concentration of the same substance entering the air in the room.
If there are several sources of harmful emissions in the workshop, then the calculation is carried out individually for each. And the overall result is the maximum obtained value of the required volume of air entering the workshop. Because calculations are made based on the influx of fresh air, then it must be clearly understood that exactly the same volume must be pumped out of the room.
Industrial hood filtration
Before the air enters the room, it is purified using filters. It is also important to clean the air mass leaving the workshop. There are three types of filters:
- Porous. The basis of the cleaning element was porous material, like a traffic jam.
- Absorbing. This filter contains a material that actively absorbs harmful emissions from the environment.
- Fabric. Perhaps the most common filters. The fabric is good at retaining various impurities from the air during the filtration process.
If the source of emission before exhaust is massive, then so-called multi-stage filtration is used. It uses several types of filters to better clean the surrounding area of impurities.
Bulk filters are also available. But they are used extremely rarely in industrial hoods due to their low efficiency in purifying the air mass from contamination.
Promising directions for industrial hoods
One of the promising directions in creating hoods is the use of recuperators in the ventilation scheme. The basic principle of this device is to carry out heat exchange between the air flow entering the room and leaving it. Thanks to the use of recuperators in the ventilation system, it is possible to save up to 50% of the heat accumulated in the workshop. In them there is an intersection of both flows. IN simple version the pipeline from the initial emission to the exhaust is blown with air entering the workshop.
Another direction for improving industrial hoods was the replacement of galvanized air ducts with plastic ones. This significantly reduces the cost of piping design for production premises.
Application asynchronous electric motors in the fan drive, significantly reduced the noise from operating equipment, and also increased its efficiency.
Conclusion
According to some estimates, manufacturing enterprises Around the world, up to 170 million tons of various substances are emitted into the Earth's atmosphere. And a considerable amount of them gets there thanks to emissions from the exhaust from the workshops of factories and plants. Therefore, along with creating conditions for employees to work at the enterprise, the exhaust hood is also required to filter the exhaust air. This aspect is strictly regulated at the level of environmental organizations in many countries around the world.
During operation, indoor air changes its parameters - temperature, humidity and composition under the influence of a variety of factors: changes in outdoor air parameters, heat, moisture and carbon dioxide from people, dust and other harmful substances from operating equipment, machines, installations. In this regard, it is necessary to carry out air exchange, i.e. remove contaminated indoor air and replace it with purified fresh (outside) air. The task of ventilation is to ensure air exchange in industrial premises to maintain the design parameters of the air in them.
Air parameters can be:
- comfortable and provided by ventilation systems for residential and administrative buildings;
- acceptable, achieved through the ventilation of industrial buildings.
Ventilation systems for industrial premises are often faced with other tasks: removal of smoke (in case of fire), dust and harmful substances (during the operation of machines, units and equipment). Ventilation of industrial premises is a set of devices and measures that provide calculated air exchange. Depending on the air flow being processed, a distinction is made between domestic (up to 10,000 m³/hour) and industrial ventilation (over 10,000 m³/hour). Ventilation of industrial buildings is a mandatory measure in production workshops, hangars and other premises in which technological equipment, people or mechanisms are working.
Ventilation of industrial buildings
Industrial ventilation equipment because of large quantities The transported air differs in its weight and size characteristics, energy consumption and increased requirements for its reliability and safety. The operation of any ventilation, including industrial ventilation, is ensured by several engineering systems called ventilation systems. They consist of devices of different designs, each of which performs its own function:
- air circulation - fans;
- air purification – filters of various cleaning classes;
- air flow regulation – air valves and dampers;
- heating and cooling of air – air heaters and air coolers;
- air distribution throughout the room - diffusers, anemostats and grilles;
- air supply and removal - air ducts;
- vibration reduction – flexible inserts and vibration isolators;
- noise reduction – noise suppressors.
Ventilation of industrial premises
Activities include proper management of industrial ventilation, compliance with standard air velocities in air ducts to reduce the level of aerodynamic noise, compliance with manufacturing technology, installation, and sealing of air ducts to reduce leaks to a minimum. Currently, for ventilation of industrial premises and simultaneous organization inflow and exhaust are used industrial ventilation units, allowing you to perform most of these functions using one unit - air handling unit. The peculiarity of these installations is that their design combines supply and exhaust unit, which in turn allows you to get more favorable price, apply various recovery systems and make the ventilation process of industrial premises more efficient.
Peculiarities
According to their purpose, ventilation units are divided into:
- inlet;
- exhaust;
- supply and exhaust;
- recuperative (supply and exhaust with recuperator).
When installing ventilation systems V industrial building it is necessary to take into account not only their features, but also their types. Ventilation in production has the following classification:
Supply;
- exhaust;
- local;
- general exchange;
- supply and exhaust;
- natural;
- mechanical.
Each type has its own distinctive features, advantages and disadvantages compared to others.
Forced ventilation
The system feeds fresh air outside in an organized manner. The mass escapes outward using pressure through cracks and openings in windows and doors. Supply ventilation can have a ducted air outlet, as well as a special valve. It prevents the spread unpleasant odor from other rooms and does not allow the contaminated composition to pass between neighboring rooms. The capacity can be 500 m3/h, which ensures fast air supply and replacement of the entire composition in a set time unit. Depending on the area of the room, you can choose required power devices.Exhaust ventilation
Installing such a system allows you to thin the air even at large area. It pulls out the contaminated composition, and instead it enters clean through the cracks, holes and window openings. The device helps remove exhaust air and all combustion products that arise during the operation of the enterprise. The performance of such a hood must be perfectly balanced to the volume of air in the room. Its main advantage is its widespread installation in industrial premises due to the simplicity of design and installation. One of the leaders in the production of fans is the VENTS plant.Supply and exhaust ventilation
The most popular type in enterprises. Combines everything best properties both systems, which allows you to achieve better results, quickly and effectively purify the air. This does not require additional installations and equipment, the purchase of which may affect costs. The peculiarity of the combined system is its functionality. It naturally attracts clean air and returns the contaminated air outside the building in the same organized manner.Local ventilation
The main purpose of the installation is local air supply. It also removes the contaminated composition from specific places where the largest amount of harmful substances is formed. The system is used in cases where it is possible to determine the location of contamination and prevent the spread of bacteria throughout the room. This type is used only in industrial enterprises.General ventilation
The use of this type involves uniform creation of air flow under the same environmental conditions. The air temperature, its humidity and the mobility of air masses must be the same throughout the entire volume of the room. The system is provided in case bacteria spread in space and there is no way to connect them all together. Usually installed when there is little air pollution, which allows you to quickly clean it.All types of ventilation have their advantages. They are quite simply mounted on the surface and are not difficult to maintain. The choice of system depends on its capacity, as this affects the level of performance and ensures clean air. Installation of a ventilation system in production – important stage ensuring labor safety and maintaining a comfortable and clean climate.
