How does an exhaust fan work? 50

1. Basic principles.

Exhaust fan. It belongs to the axial fan.

one. It is mainly used in negative pressure ventilation and cooling engineering, and is called industrial exhaust fan. The exhaust fan has the characteristics of large air duct, large blade diameter, large exhaust air volume, ultra-low energy consumption, low speed and low noise. ‍‍

It can be used together with the cooling curtain to solve the ventilation and cooling problems in one step. During the operation of the exhaust fan, a negative pressure environment will be formed in the room. If a cooling curtain is installed on the other side wall of the exhaust fan outlet, the exhaust fan will not only exhaust the stuffy air from the room to the outside, but also enter the room through the cooling water curtain and contain abundant water vapor.

The low-temperature air is sucked into the room, so as to achieve the effect of ventilation and cooling.

2. Ventilation principle.

In the process of exhausting the air from the exhaust fan, the indoor air pressure will drop, and the indoor air will become thinner, forming a negative pressure area, and the air will flow into the room due to the air pressure difference compensation. In the practical application of industrial plants, the exhaust fan is usually installed on one side of the plant, the air inlet is on the other side of the plant, and the air is convection from the air inlet to the exhaust fan. In this process, the doors and windows near the exhaust fan remain closed, and the forced air is compensated for by the door and window on the side of the air intake.

The air flows into the workshop in an orderly manner from the air intake, flows through the workshop, and is discharged from the workshop by the exhaust fan. The ventilation is thorough and efficient, and the ventilation rate can be as high as 99%. Through specific engineering design, according to the need to design the ventilation speed and wind speed, any high heat, harmful gases, dust and smoke can be quickly discharged from the workshop, and any poor ventilation problems can be completely solved at one time.

Ventilation can be achieved within seconds of turning on the fan.

3. Cooling principle.

The exhaust fan can quickly discharge the stuffy air in the room, and suck the air on the other side of the outdoor into the room, so that the temperature is the same as the outside temperature, and the temperature in the workshop will not rise. In the process of air flow, the body heat will be taken away, and the air flow will accelerate the evaporation of sweat and absorb the body heat, so that the body feels cool, to achieve the same cool as the natural wind.

As you can see from the schematic diagram above, the centrifugal wind wheel is pumping outward. The blowing direction of the centrifugal wind wheel is to the left and right, rather than vertically downward.

The working principle of the exhaust fan is relatively simple, the impeller rotates through the motor, the impeller pushes the air movement, produces a directional air flow, and replaces the air in the room through the movement of the air flow.

The machine of axial impeller generally extracts air from the open space into the open space, and is generally not connected to the air duct, for the machine with relatively large air volume, the axial flow exhaust fan for industry, the axial flow fan is connected to the air duct, the air volume of the centrifugal impeller exhaust fan is relatively small, and the wind pressure is larger, there is an air inlet for the open space, the air is exhausted through the air duct, and the air inlet and outlet are connected to the air duct products, mainly due to a certain wind pressure, it can be connected to a certain length of air duct, and the space exhaust in the closed room is there. The through-flow exhaust is mainly used in the exhaust of the air curtain machine.

The working principle of the exhaust fan is very simple, that is, a motor with a few maple leaves keeps rotating, and then the rotating leaves will stir the wind speed, so that the air is circulated and plays the role of exhaust.

The exhaust fan generally circulates the indoor air, and you ask this question in chemistry, which should be to make the indoor solvent volatilize and be quickly eliminated, so as not to cause the solvent content in the indoor air to be too high, which will cause ** or poisoning.

Introduction: The exhaust fan can not only ensure the removal of indoor dirty air, but also continuously inhale fresh outdoor air to achieve the effect of ventilation and cooling. Therefore, it is very important to purchase a cost-effective exhaust fan for indoor air circulation.

Next, I will introduce what is an exhaust fan and the principle of an exhaust fan.

Exhaust fan is a kind of air conditioning appliance that drives the fan blade rotation by the motor to drive the airflow and make the indoor and outdoor air exchange. Also known as ventilation fan. The purpose of exhausting.

It is to remove the dirty air in the room and adjust the temperature, humidity and feel. Exhaust fans are widely used in homes and public places.

1. Exhaust fan classification

1. Press the intake and exhaust port

1) Exhaust fans are divided into intake and exhaust outlets:

Partition wall type: Both sides of the partition wall hole are free space, and ventilation is carried out from one side of the partition wall to the other;

Catheter exhaust type: one side intakes air from free space while the other side is exhausted through the catheter;

Catheter intake type: one side is inlet through the catheter, while the other side is vented into free space;

Full duct type: ducts are placed on both sides of the exhaust fan, and air is inlet and exhausted through the duct.

2) According to the form of airflow, it is divided into:

Centrifugal: air enters from a direction parallel to the axis of rotation and discharges perpendicular to the direction of the shaft;

Axial flow: air enters from the direction parallel to the axis of rotation and is still discharged parallel to the direction of the axis;

Cross-flow: Air enters and exits perpendicular to the direction of the shaft.

Second, according to the ventilation mode

There are three types of ventilation types for exhaust fans: exhaust type, suction type, and combined type.

Exhaust type: air enters from the natural air intake and discharges dirty air through the exhaust fan;

Inhalation: Fresh air is inhaled through the ventilation fan and dirty air is discharged from the natural exhaust port;

Combined: Suction and exhaust are done by the ventilation fan.

2. Specifications

1. At present, there are three main appearance specifications of exhaust fans circulating on the market, namely:

1) 1380*1380*kW.

2) 1220*1220*kW.

3) 1060*1060*kW.

2. The mode of rotation can be divided into two types: belt rotation and motor direct rotation

1) The speed of the belt-type rotating exhaust fan is generally 400 450 rpm, which has the characteristics of low noise;

2) The motor directly rotates the exhaust fan at a higher speed, which is 440 720 rpm.

3. Structural classification

From the leaf structure, there are three main structures: five leaves, six leaves and seven leaves.

The exhaust fan uses air convection to keep the room in a negative pressure state, forming a suction force, continuously inhaling the outdoor air and discharging the stuffy air indoors, so as to achieve the effect of ventilation and cooling.

If you want to have a healthy and fresh living environment, the exhaust fan is an indispensable household item, and it is important to choose a good exhaust fan. What is an exhaust fan I introduced above The principle of an exhaust fan I hope it will be helpful to you.