Choice of smoke exhaust fan according to aerodynamic characteristics. Roof smoke exhaust fans
Recently on Russian market ventilation equipment, there is a sharp increase in interest in smoke ventilation systems and in the main components of these systems - smoke exhaust fans. This is largely due to the approval of the new " Technical Regulations about the requirements fire safety", One of the sets of rules of which is entirely devoted to fire requirements for heating, ventilation and air conditioning systems:" Set of rules 7.13130.2009 Heating, ventilation and air conditioning. Fire safety requirements "
The production of smoke exhaust fans is one of the main activities of the VKTtechnology company. This article addresses the following issues:
Types of smoke exhaust fans
The main differences between smoke exhaust fans are the design of the casing and the type of impeller. The most common and demanded fans on the Russian market are roof radial fans and volute casing radial fans .
Rooftop radial fans
Rooftop radial fans have a number of advantages over others.
At first, the fans are placed on the roof, the area of which is usually not used. This allows you to abandon the equipment of special rooms for the placement of smoke exhaust fans, and, as a result, increase useful area premises.
Secondly, the fans are placed on a shaft made of a construction design, which in many cases makes it possible to dispense with the laying of a vertical duct. It is also a clear advantage that air is discharged directly from the fan into the environment, and there is no need to use an air duct to remove combustion products from the fan.
Body design roof fans smoke exhaust is of two types: fans with side discharge and upward discharge. When choosing the design of the fan housing, one of the requirements must be taken into account regulatory documents: emission into the atmosphere should be provided at a height of at least 2 m from the roof made of combustible materials; the emission of combustion products at a lower height is allowed when the roof is protected with non-combustible materials at a distance of at least 2 m from the edge of the outlet. The advantage of a side blowing fan is its relatively low cost.
The advantage of a fan with an upward discharge is a higher location of the mark of the emission of combustion products relative to the level of the roof. For installation of a roof smoke exhaust fan, a mounting sleeve is used. The upper flange of the mounting shroud is connected to the outer flange of the fan. The lower part of the mounting sleeve has different connecting dimensions depending on the mine design. One way or another, the lower part of the glass rests on the shaft. The weight of the fan is transferred through the mounting sleeve to the shaft. There is a standard the lineup mounting sleeves, which is presented in the VKT product catalog. Also, depending on the design of the shaft, our designers select glasses with individual connecting dimensions. In certain cases, the use of an insulated mounting sleeve is required. In this case, the body of the glass is covered with thermal insulation, and an insulated air damper is placed inside the glass.
Radial volute casing fans
Sometimes the use of roof smoke exhaust fans is not possible. In these cases, applies volute casing radial fan... The advantage of this fan is that it can be placed almost anywhere in the building or next to the building, taking into account the norms for the placement of equipment. In addition, it is possible to connect an air duct to this fan both at the inlet and at the outlet. Considering that the fan is capable of developing a pressure of up to 2000 Pa, it is possible to remove the combustion products from the fan over fairly long distances. Air ducts on both the suction and pressure side must have a certain fire resistance. As a rule, the required fire resistance is achieved by covering the air ducts with a fire retardant compound.
Calculation and selection of a smoke exhaust fan
When calculating and selecting smoke exhaust fans, it should be borne in mind that all the characteristics presented in the catalog correspond to normal atmospheric pressure and an air temperature of 20 o С. , where T is the value of the temperature of the removed smoke in o C.
The VKTtechnology company produces fans with backward curved blades. When selecting a fan for one operating point, usually several fans are suitable. As one of the options, you should choose the fan with a lower rated motor power, if this characteristic is relevant. V otherwise it is recommended to use the smaller fan in order to reduce its cost.
It should also be remembered that at different points of the operating curve the fan consumes different power, that is, the rated motor power depends on the characteristics of the network.
The principle of operation and control of the smoke exhaust fan
The principle of operation and control of the smoke exhaust fan is quite simple. A control panel is used for the fan. The signal to turn on the fan comes to the control panel from the fire control panel.
As a rule, the smoke exhaust fan is used only in anti-smoke ventilation, but sometimes it can be used in general ventilation systems. In this case, a frequency converter is used, which, upon receiving a signal from the fire control panel, increases the fan speed. This scheme is quite beneficial, since it allows you to abandon the additional general ventilation system, using only the smoke exhaust system.
The TEKHVENTPROM company offers roof smoke exhaust fans (VRMK) radial type... Direct purpose - air extraction in residential and industrial premises.
All prices on request
Usually, smoke exhaust roof fan installed on the roof of the building. They are used to remove high-temperature smoke that occurs during a fire, as well as to ventilate the air with the environment. Horizontal and vertical views, as well as four and two-way transported air outlet.
Purpose of VRMK roof smoke exhaust fans
The fans comply with the fire safety requirements established in GOST R 53 302-2009, SP 7.13130.2009 and are designed to move smoke-air mixtures formed during a fire with a temperature of 400 ° C for 120 minutes and 600 ° C for 120 minutes.
The transported medium must be non-explosive, not contain explosive gas mixtures, sticky substances, fibrous, abrasive materials, cannot be more aggressive towards carbon steels of ordinary quality than air. The content of dust and other solid impurities in it is not more than 10 mg / m³. For aggressive and explosive environments, the fans are made of of stainless steel and dissimilar materials.
VRMK roof smoke exhaust fans used in emergency systems exhaust ventilation industrial, public, administrative, residential and other buildings, except for categories A and B according to SP 7.13130.2009. It is forbidden to operate the fans for other purposes.
Operating conditions of roof smoke exhaust fans
It is forbidden to operate the fans for other purposes.
The fans are designed for operation in a moderate (U) climate of the 2nd category of placement in accordance with GOST 15150-69 at a temperature environment from minus 45 ° to + 40 ° C, relative humidity up to 100% at a temperature of 25 ° C. It is allowed to operate the fans in a temperate climate of the 1st category of placement.
RMS value of vibration velocity external sources vibration in the places where the fan is installed should not exceed 2 mm / s.
Main technical data and characteristics of roof smoke exhaust fans
3.1 The design of the fans, their overall and connection dimensions are shown in Figures 1, 2, 3 and in Table 1.
3.2 The aerodynamic characteristics of the fans are shown in Figures 4-27.
3.3 Specifications electric motors are shown in table 2
3.4 Mounting the fan on glasses (passage units) of the SMKU in Fig. 4
1 - base, 2 - impeller, 3 - fan diffuser, 4 - casing, 5 - wall, 6 - electric motor blowing impeller, 7 - baffle impeller, 8 - hub, 9 - screen, 10 - bracket, 11 - blowing system diffuser electric motor.
Fig. 1 Main parts and assemblies of the fan
1 base, 2 - impeller, 3 - fan diffuser, 4 - casing, 5 - wall, 6 - electric motor blowing impeller, 7 - baffle impeller, 8 - hub, 9 - screen, 10 - bracket, 11 - motor blowing system diffuser , 12 - flare assembly, 13 - flow direction
Fig. 2 Main parts and assemblies of the fan
A - length, width of the fan;
Н - fan height
D- diameter;
C is the distance between the centers of the connecting holes.
Rice. 3. The main parts and assemblies of the fan
Rice. 4. Mounting the fan on glasses (passage nodes) SMKU
Main overall and connecting dimensions
fan VRMK-3,15DU - VRMK-14DU
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Overall and connecting dimensions mm. |
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Fan index |
side throw |
upward throw |
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VRMK-3.15DU |
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VRMK-3.55DU |
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VRMK-4.5DU |
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VRMK-5.6DU |
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VRMK-6,3DU |
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VRMK-7,1DU |
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An axial fan is usually an impeller (K) located in a cylindrical casing, fixed on the shaft of an electric motor. In addition, the inlet guide vane (VNA) and the SA straightening device can be used. Our enterprise manufactures axial industrial fans according to K and K + CA schemes. In an axial fan, the medium to be transported passes along the axis of rotation of the impeller. The main part of the axial fan is the impeller, due to the rotation of which part of the drive energy is transferred to the air to create a certain pressure and speed of the transported medium. The impeller consists of a sleeve and blades spaced evenly around the circumference in a certain way. The blades are made of bulk or sheet and can be rotary or fixed. The straightening device (SA) is used to convert the dynamic pressure associated with the swirling speed of the flow behind the impeller into static pressure. In this case, the static pressure and static efficiency increase without increasing the power consumption. In some designs, the CA additionally performs the functions of a power unit, where an electric motor or a bearing unit can be placed. Roof axial supply fans, type VKOP and VKOP-K VKOP VKOP-K Installations of the UVOP type are used in supply smoke ventilation (PD) systems and are installed on the roofs of buildings and structures. VOF-DU VKOP-S The use of the VKOP-S fan in tandem with the VOF-DU fan creates a harmonious pair of industrial installations on the roof of the building, created in the same style and having a modern design. IN TO VKO-K VKO-K is manufactured in various designs: The VKO and VKO-K fans, due to a different parameter field, complement the range of radial-type roof fans. To reduce the levels of vibration transmitted from the fans to the bases and attached air ducts, use of various types vibration isolators and flexible inserts. Appointment Design The material of the hose and flanges is determined by the fluid to be transported. A corresponding insert design is provided for each fan version. Operating conditions
A fire occurs due to careless handling of fire. The fire site may be located in hard-to-reach places, so arriving firefighters cannot immediately neutralize it. The main danger to human life is represented by combustion products and temperature rise. In order to secure evacuation, fire-fighting systems specialists have developed roof smoke exhaust fans. Types and characteristicsThe roof fan is one of the units of the smoke exhaust system, which is designed to remove the hot gas mixture from the building. It is he who takes on the main heat stroke and, thanks to his design, continues to work until the fire is completely eliminated. The temperature of the removed gas mixture can reach +900 ° С. Roof-mounted smoke exhaust fans are of three types, depending on the method of removing the gas mixture to the outside: axial, diagonal and radial. - one of the simplest in its design. It is a cylinder with blades in a protective casing. Rotating, the propeller blades artificially reduce the pressure and thereby pull out gas mixture. Appearance resembles a simple home fan.
A diagonal fan is an elongated drum, inside which one or more impellers are placed. The blades suck in hot air in the direction of the axis, and throw it out in a diagonal, hence its name. The advantage of this unit is its high performance and low noise level. A centrifugal or radial fan blows smoke out of the room thanks to the special design of the blades. During operation, such a fan throws combustion products out into the street due to the centrifugal force created by the curved blades. With a high air exchange, such a fan is quite noisy, so it is usually installed in industrial buildings. Roof smoke exhaust fans are automatic and manual. Automatic devices equipped with special sensors. They are triggered when the temperature rises. Hand models equipped with a special button to turn on. Criterias of choiceBefore choosing a roof fan, a number of criteria must be considered:  The assembly of the roof fan structure is carried out at the factory.... This avoids design inaccuracies that reduce aerodynamic performance. As a rule, the smoke exhaust fan model is chosen at the design stage. But if the fan becomes unusable during operation, then you can choose it yourself, according to the existing nomenclature.
In the designation of the VR-10-DU-2ch / 600 (400) ° С-5.5 / 710 fan, the letters indicate its type (“VR” - radial, “DU” - smoke exhaust). The numerical values in order determine its main parameters:
Some manufacturers add the direction of rotation of the wheel and the position of the body in degrees to the standard nomenclature. Installation of devicesInstallation of the fan depends on the type and angle of inclination of the roof. To begin with, a hole is made and a check valve is installed in it, if necessary, a vibration-absorbing structure is mounted. Then the pallet is attached, and the fan structure itself is on top. It is important not to skew during installation, as the fan will not work in such positions. After fixing, it is necessary to treat all joints with a special refractory sealant.
When choosing a rooftop smoke exhaust fan, it is necessary to remember that it helps people not to get poisoned and not burn themselves with combustion products during a fire, therefore, its choice must be carefully thought out. It should be powerful, compact, and low in noise. The structure must be lightweight and fire resistant. KVDU - roof smoke exhaust fan DU - smoke exhaust PVK - PetroVentKomplekt When a fire occurs and a fire starts, people in the room are not only in danger of the fire itself, but also combustion products that can lead to complete disorientation and loss of consciousness. For this reason, it is important from the very first seconds to ensure that the smoke is removed by means of a special ventilation structure. Purpose and deviceThe company "PetroVentKomplekt" produces smoke exhaust fans, axial fans for pressurizing air and roof supply fans, which are successfully used at construction, industrial and administrative facilities throughout Russia and the customs union. Fastening the roof radial fan DYM (VKR)Roof smoke exhaust fans DYM-F (exhaust upward) and DYM-N (exhaust to the side) remove combustion products from a room engulfed in flames, thereby providing conditions for work fire brigade and the survival of those affected. Both models, DYM-F and DYM-N, are radial smoke exhaust fans capable of operating at temperatures up to 600 C for two hours. Additional equipment includes mounting sleeves for fastening to the roof (models MSU, MSU-VKOP), as well as check valves and control panels. Smoke exhaust fans from "PetroVentKomplekt"The specialists of the technical department of our company have developed an energy-efficient fan impeller, which allows, with the same efficiency, the use of smoke exhaust systems of more compact dimensions and electric motors of lower power. In addition, all DU roof fans manufactured by PetroVentKomplekt have mounting dimensions that are fully compatible with equipment from other manufacturers. This allows us to use our equipment at any facility and for the implementation of even the most complex projects... If necessary, the professionals of our company will help you choose the optimal equipment and elements of the installation kit, as well as assist in commissioning at the facility. If you want to buy smoke exhaust fans at the manufacturer's price, get a full free consultation from our technical specialist by calling: + 7-812-309-48-11, or by sending a request through the feedback form on the website. Already now you can download a price list for products, a technical catalog, a selection program and questionnaires: Selection program | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
