If the pipe is devoid of a vent for ventilation, difficulties with traction can arise during the operation of the system. Smoke outflow can be suspended or stopped for several reasons, including:
- snow;
- rain;
- strong wind;
- low height;
- incorrect location;
- insufficient pipe diameter.
The deflector can handle all these problems.
Deflector Assignment
The turbo deflector for ventilation allows you to reduce the influence of external factors on the system and directs them to the benefit of the entire structure. This need is due to the fact that quite often atmospheric conditions determine the efficiency of the ventilation system. Due to the lifting force, air flows begin to circulate . This effect occurs due to the temperature difference outside and inside the room. Thus, the wind adjusts the ventilation, accelerating or obstructing the natural air exchange.
The turbo deflector for ventilation outwardly resembles a cap, which should be located in the upper part of the exhaust duct. This unit minimizes the negative impact of rainfall on equipment, protects the mine from birds and debris, and also enhances and activates traction by redirecting and generating wind flows. To increase traction in the chimney, an umbrella design is used. If we are talking about a deflector installed on a chimney, then it acts as a spark arrester.
Principle of operation
The main idea of the operation of the above device is the reflection of the air flow from the diffuser. As a result of this, Bernoulli's law begins, which consists in the fact that the air flow is dissected by a diffuser, which leads to rarefaction of air and the appearance of draft.
The device can work more efficiently if you install it on a channel located with a bend or along a curved line. If you increase the draft in the pipe, then the efficiency of the device can increase by 20%.
The main types of deflectors
Modern ventilation deflectors for sale differ in their functionality and design. Among others, a rotary deflector should be highlighted. The most common model is the Grigorovich deflector variant, which is great for use on ventilation and chimney pipes. The design of this model is very simple, which allows you to build it yourself.
The described products can be classified according to the material in the basis, which can be:
- plastic;
- stainless steel;
- copper;
- Cink Steel;
- aluminum.
Structurally, deflectors are divided into:
- open plate type products;
- in the form of a star;
- Tsaga deflectors;
- devices operating on the principle of Grigorovich;
- H-shaped constructions.
The most popular today is the Grigorovich deflector, due to the simplicity of its design. We can distinguish the described devices in two large classes. Deflectors can be:
The former are motionless, while the latter are rotating.
Description of the main types of deflectors
The ventilation deflector may be a disk design. It is effective and simple. Rotary models are a complex device with a special blade system and a rotating part. A distinctive feature is higher efficiency and impressive cost.
On one tip of the H-shaped model contains two deflectors at once. But the rotary nozzles with the keel are weathervanes that rotate the structure in the direction of the wind. This allows you to ensure the direction of flows into the system of the blades and holes, causing the effect of gas ejection from the duct.
One of the varieties of deflectors is a rotational design
Rotary reflectors are rotating devices that are used not only in ventilation systems, but also in chimneys. An engine is not required for operation. The rotation is provided by the action of wind force.
A rotating turbine creates a vacuum in the channel, in the process, excess moisture and heat, dust, harmful gases are drawn, and the interior is protected from condensation. The direction of the wind does not affect the rotation of the deflector head. The vacuum only enhances the draft in the ventilation and smoke channels. The head eliminates the occurrence of reverse thrust. It is especially convenient that the installation of such a device does not require the supply of electricity.
Description of the Statodynamic Deflector
The French company Astato has developed a statodynamic deflector, with which you can achieve increased traction flow of the system with natural ventilation. The nozzle is installed on houses of any number of storeys; they can be new or reconstructed. After turning on the electric motor, the aerodynamics of the channel are preserved, and the degree of vacuum is the value of the pressure and pressure of the fan.
The installation of this device can be carried out by the method of nipple connection, which is suitable for round ventilation ducts. If you have to work with a group of shafts and rectangular ducts , an adapter is used. The structure can be controlled manually or by means of a pressure sensor and a time switch. It is based on aluminum.
The described deflector is presented for sale in six positions, they differ in nominal diameter, which varies from 16 to 50 cm. Choosing a modification of the DYN-Astato series, you get a device with a two-speed fan. The cost of such products can reach 24,000 p., Which depends on the size.
More about the principle of action
The vent of the ventilation system will have a design that depends on the area of its application. For example, in the supply and exhaust systems of natural ventilation, the described structures are located on the head of the exhaust channel. This allows you to increase traction, which is provided by the creation of the region of low pressure.
In addition to the Bernoulli law, it can be noted that the effect of rarefaction of air is created by means of a changing section. With increasing air velocity, the pressure drop becomes more impressive. Due to the wind energy that blows through the pipe, a vacuum is created in the tip area, which contributes to the upward movement of the masses inside the pipe. This creates additional traction.
The exhaust pipe deflector consists of several parts, among them:
- diffuser;
- cap or umbrella;
- external cylinder or housing.
A diffuser is a piece of pipe that has the shape of a truncated cone. It is worn on the pipe with the narrow side. A diffuser is needed to increase the pressure in the pipe in the head area, which increases the pressure difference and the activity of ejection of exhaust air. The ventilation deflector umbrella is necessary to protect the channel from the entry of debris, precipitation and foreign objects. As for the housing or the external cylinder, it acts as a divider of the air flow, creating a reduced pressure inside.
Grigorovich cap design
Grigorovich deflector has a slightly different design. The device includes the following nodes:
- inverse cone;
- umbrella or hood;
- diffuser.
The latter is represented by the same truncated body, but it is worn on the pipe with the wide side. The section of this side should be larger than the section of the head. This part is called a glass. The cap protects the structure, as in the previous example of the device. Under the cap, the inverse cone is set downward. It eliminates the accumulation of air under the umbrella and, together with the diffuser, creates a tapering wind flow.
This type of ventilation deflector works according to the principle of ejection in two directions. One of them is directed towards the reverse housing, while the other is towards the wide side of the diffuser. In this case, the flow velocity under the inverse cone increases due to the fact that the channel narrows, which leads to an increase in the pressure difference.
Finally
Plastic deflectors - this is just one of the varieties of such products that are offered by the modern market. Manufacturers make caps from stainless steel, aluminum, ceramics, galvanizing and copper.
From the point of view of the balance of quality and cost, aluminum and steel products are the best solution. Due to the high cost of copper deflectors are used very rarely. An alternative is the metal structure, which is coated with plastic. Such devices are a symbiosis of strength and decorativeness.