What is a negative pressure fan?
A lot of people do not understand this concept, the following details of the negative pressure fan is what. The negative pressure fan in the air cooler is a kind of suction fan, because the working principle is to use negative pressure ventilation, the physical principle of air convection to force air convection ventilation and cooling, so it is called the negative pressure fan. Negative pressure fan is the best choice for ventilation and cooling, especially used in industrial plants, pig farms, chicken farms, greenhouses, Internet cafes and other places. Negative pressure fan is mainly used for the overall solution of high temperature, sultry, smoke, odor, dust and other poor ventilation problems. Negative pressure fan is low pressure fan. Negative pressure fan is commonly known as wet curtain fan, glass fiber reinforced plastic fan, galvanized sheet fan, iron fan, industrial fan, negative pressure exhaust fan, negative pressure ventilation fan, animal husbandry fan, etc.

One, the type of negative pressure fan:
Negative pressure fan this kind of product is various, mainly from the following aspects:
1, from the frame material distinction: FRP glass fiber (FRP), galvanized sheet, plastic steel;
Galvanized sheet negative pressure fan is made of galvanized iron sheet (commonly known as tin sheet). It is the most common negative pressure fan in the market. Because it is affordable, many manufacturers choose negative pressure fan made of this material. But the service life of this negative pressure fan is short;
FRP negative pressure fan:
FRP glass fiber negative pressure fan (FRP is fiber reinforced plastic) commonly known as FRP fan;
FRP features:
(1) light weight and high strength.
(2) good corrosion resistance. To the atmosphere, water and general concentration of acid, alkali, salt and a variety of oils and solvents have better resistance.
(3) Good electrical performance. Excellent insulating material, used to make insulators. Good dielectric protection at high frequencies. Microwave transmittance is good.
(4) good thermal performance. FRP has low thermal conductivity and is not easy to deform.
Because of the above characteristics of FRP, FRP negative pressure fan is high temperature resistant, acid and alkali resistant, light and stable, and has a longer service life.
Plastic steel negative pressure fan: rarely used on the market at present;

2. Transmission mode: the transmission mode of the negative pressure fan is divided into direct type and belt type.
From the perspective of this transmission mode, the transmission mode affects the air volume, noise, and maintenance of the negative pressure fan; Direct type is superior;
1. The blades of direct negative pressure fan are directly installed on the motor, which reduces the power loss caused by transmission. For fans with the same power, the air volume of direct negative pressure fan is about 10% larger than that of belt type. The belt of belt-type negative pressure fan will become loose after a long time, and the air volume of the fan will decrease significantly after loosening.
2. Direct negative pressure fan also has no noise caused by belt friction.
3. Belt type should be maintained. Generally, the negative pressure fan belt can be used for two years (imported) and a small amount can only be used for one year, especially the negative pressure fan installed at high altitude is also difficult to replace.

What is an axial fan
Axial flow fan is the air flow in the same direction as the axis of the blade (that is, the flow of the wind is parallel to the axis), such as electric fans, air conditioning fans are axial flow fans.

A common example of an axial fan is a typical bench type fan. It is called "axial flow" because the air passing through the fan does not change direction, but flows parallel to the fan axis. Axial fan is usually used in high flow requirements and low pressure requirements of the occasion.

Axial fan blades work in a similar way to the wings of an aircraft. But whereas the latter push lift up the wings and support the weight of the aircraft, the axial fan holds the air in place and moves it around.

The cross section of an axial fan is generally a wing section. The blade may be fixed in position or rotated about its longitudinal axis. The Angle of the blade to the airflow or the blade spacing may be unadjustable or adjustable. Changing blade angles or spacing is one of the main advantages of axial fan. Small blade spacing Angle produces lower flow rate, while increasing spacing produces higher flow rate.

Advanced axial fans can vary the blade spacing as the fan is running (much like a helicopter rotor), changing the flow rate accordingly. This is called a vane adjustable (VP) axial fan.

Axial flow fan, also called local fan, is a kind of fan commonly used in industrial and mining enterprises. Its motor and blade are in a cylinder, and the shape is a cylinder. It is used for local ventilation, convenient installation, obvious ventilation effect, safety, and can be connected to the air duct to send the air to the designated area.

What are the differences between axial fan and negative pressure fan
As we all know, there are a lot of high temperature factories are installed with a large number of axial flow fans, but the workshop is still so hot to the hopper, or so much dust and odor.
To the surrounding air.
An example shows that if you stand next to the axis of an axial fan, you will not feel the air flow at all, even though there is a lot of wind on the axis.
And suction fan is like a reverse atomizer, it is to absorb the air horn shaped, not only drives the fan axis of airflow, but by the fan in the outward show trumpet-shaped scroll air, we were standing next to the axis of the fan impeller to the powder machine will also feel a strong airflow, this feature determines its exhaust thoroughly with high efficiency.