centrifugal air blower sirocco blower cross flow fan

What Is a Centrifugal Blower?

Many industrial processes require the movement of air or other gas. Whenever you need a continuous flow of air or gas, centrifugal blowers can help. They belong to a class of machines call turbomachines.

Turbomachines

Turbomachines transfer energy between a rotating shaft and a fluid. The fluid can be a liquid, such as water, or a gas, such as air or steam. Turbines transfer energy from the fluid to the shaft. Fans, blowers and compressors transfer energy from the shaft to the fluid, which is usually air.

Centrifugal Blower Characteristics

Blowers, fans and compressors are classified by a measure called the pressure ratio --- the outlet pressure divided by the inlet pressure. Fans have the lowest pressure ratio, compressors the highest, and blowers are in the middle. The flow rate of a blower depends on the system resistance: The lower the resistance, the higher the flow rate and the power requirement. The efficiency of the blower is highest at some intermediate flow that should correspond with the normal operating flow.

Applications

Blowers move materials in the form of fine particles through ducts and pipes. They provide cooling airflow and blow-off air. Blow-off air is used to dry or clean parts before processing them. Blowers also provide combustion air. The suction side of a blower can provide a vacuum for cleaning or picking up parts.

Centrifugal Blowers & Fans

Centrifugal Fans and Blowers typically have one of six types of wheels that draw the air into the inlet of the blower housing, through the wheel, and discharges it at 90 degrees out through the discharge of the housing.

The two most common types of Centrifugal Blowers are Pressure Blowers and Volume Blowers.

Pressure Blowers are designed to draw or push air at high pressures, rated in static pressure water gauge (SPWG).

Volume Blowers are designed to draw or push larger volumes of air, rated in cubic feet of air per minute (CFM), at lower static pressures than Pressure Blowers.

Centrifugal Blowers are typically made of fabricated steel, stainless steel or cast aluminum.

Types of Air Blowers

Air blowers generally use centrifugal force to propel air forward. Inside a centrifugal air blower is a wheel with small blades on the circumference and a casing to direct the flow of air into the center of the wheel and out toward the edge. The design of the blades will affect how the air is propelled and how efficient the air blower is. Blade designs in air blowers are classified as forward-curved, backward-inclined, backward-curved, radial and airfoil.

Forward-Curved Air Blowers

Forward-curved blowers are impulse devices with blades that are curved in the direction of rotation. The blower accelerates air to a high velocity while rotating at a low speed. Forward-curved blower wheels spin at relatively low speeds and produce high volumes of air at low static pressures. This type of blower is incapable of operating at the speeds necessary to create high static pressures because of its lightweight construction. Still, forward-curved blowers are the most common type of air blower because they propel the most air volume in relation to blower size and speed.

Backward-Inclined and Backward-Curved Air Blowers

A backward-inclined blower, operating at roughly twice the speed of a forward-curved air blower, has flat blades that slant away from the direction of travel. This type of blower is highly efficient (low horsepower requirement) and has a rugged construction suitable for high static pressure applications. This type of air blower is best used in locations where the air is either clean or mildly contaminated. Similar to this style is a backward-curved air blower. The blades of a backward-curved blower are a single thickness throughout and curve away from the direction of travel. These blades are sturdier than backward-inclined blades and can be used in corrosive and erosive environments.

Radial Air Blowers

Radial blowers are designed for industrial use in small exhaust systems. These air blowers are capable of handling air that contains bits of dirt, grit, lint and other foreign particles while still maintaining a high-pressure supply of air for conveying and cooling. Their use in particle-laden air means that this type of blower is generally designed to be self-cleaning. Radial air blowers have the lowest efficiency levels because the blades have no curve or lean and are perpendicular to the wheel's rotation. Think of a paddleboat racing a boat with an outboard motor. No matter how fast the paddle spins, it will not catch up to the boat with the outboard motor.

Airfoil Air Blowers

Airfoil blowers have the most efficient design of all air blowers. Their blades have an airfoil shape that is wide at the center and curves down to narrow edges. Airfoil blowers are extremely efficient because they require lower horsepower levels to operate. This type of blower is used in clean air situations.

Centrifugal Fan wheels, Impellers, impeller, fan, sirocco fan, fan wheel, blower wheel

Centrifugal Fan wheels / Impellers
Specifications:
                 1. Size: Diameter in 3 - 40"
                 2. Type: Double inlet ,Single inlet. Strip type, Tablock type.
                 3. Material: Aluminum, Steel, Stainless steel SUS304, SUS316, and Galvanized steel
                 4. Motor speed: 800-3600 rpm
                 5. Fan Wheel Revolution Rotational Direction: CW (clockwise), CCW (counter clockwise)

Characteristics:
Mainly apply on blowers equipment, HVAC, oven, packing machine, kitchen hood, baking machine,
air shower, boilers for air suction and discharging.

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SIROCCO FAN REVOLUTION DIRECTION

SIRROCO FAN DIAGRAM

sirocco ventilation fan application

Sirocco fan / ventilation

fans are specifically designed for use in the ventilation of indoor environs such as kitchens. They are also useful in locations such as mines for ventilating, drying and cooling purposes.

Application: for in door and kitchen ventilation mining ventilation, cooling, drying.

blower application: small boiler kitchen hood, baking machine, packing machine, air shower, humidifier, dehumidifier, HVAC system for air suction and discharging, inflatable industry, toy castle, clean room…etc.

Application:

PCB cleaning system,bottling system,plastic auxiliary equipment.
Label printing machine,woodworking machine,paper manufacturing,packing machine,
food machine,textile machine,waste water treatment system,aquaculture industry,
ceramics and mining industry,industrial vacuum cleaning,powder conveying ,

drying machine,glass industry,ice manufacture and cooling system,etc.

sirocco fan blower
Radial Blowers
Dustcontrol fans are radial blowers, air is introduced at the center of the fan wheel
and forced outward with centrifugal force toward the fan housing. These fans can be
operated fully restricted in a ”freewheeling”condition without adverse
effect and can therefore be operated without vacuum relief valves. The fans
are designed for pressure and are overloading type units. They cannot be
operated without being connected to the restriction of a tubing system. Operation

above their maximum rated flow will result in overloading and the motorprotection will trip out.

Turbo Blower features:

1. High pressure,large air flow,low noise and light weight.
2. ADC 12, aluminium alloy material ,make light weight design.
3. I.E.C design for electric motor,full cut-off aluminium motor cover,special axis design,
in order to increase working life of the Turbo Blowers.
4. Special design of impellers,make high pressure,large air flow ,low noise and longer running life.

5. Speical damper to adjust air flow,make sure air flow can be control stable,easy to handle.(suitable for CX ,TB,HYB series Turbo Blower)