Blowers are a type of "fan" used for making air. A common type of blower is the "Squirrel Cage" design. A typical fan of this type is used in the majority of furnaces in existence today. Other types of blowers are the "High Pressure Blower" and the "Lobe Blower".
Squirrel Cage Blower
A squirrel cage blower is a cylindrical device (looking much like a drum) with the top and bottom of the drum being referred to as the "blower wheels". One of these ends is solid and the other simply a disc. There are, then, many small fan blades placed around the circumference of the drum. These small blades are fastened at each end to the circumference of the "blower wheels". The appearance of the final assembly is like a "cage" that one might house a small pet ..... like a "squirrel"????
If you're still confused about what one looks like, picture the wheeled device that keeps a hamster running forever! Better yet, here's a photo
These devices create a high volume of air for the speed at which they are operated AND are much quieter than many other air handling units that would create a similar amount of air.
Again, one of the most common uses for this device is on furnaces and air conditioners i.e. the HVAC industry.
High Pressure Blower
Another type of blower is the HIGH PRESSURE blower.
This device produces, as the name implies, high pressure air. This air is then used in processes like the printing industry. The air is brought in one end of the blower and as it is passed from one stage to the next, within the blower housing, the pressure is increased. This is similar to the action of a "compressor" but with the blower type of device, the pressure is not nearly as high BUT the volume of air is much higher.
These blowers are usually HIGH NOISE producers and the compressing nature of the device produces a significant amount of heat.
Some typical applications include:
Combustion Air, Air Drying, Product Cooling, Pollution Systems, Pneumatic Conveying, among others.
Gardner-Denver is a manufacturer of the multi-stage blower shown above. Other manufacturers produce a high pressure blower in single stage and turbine type designs. Some of these other manufacturers are New York Blower, Illinois Blower, ILG, and Spencer Turbine, among others.
This type of blower produces a high VOLUME of air at reasonably low pressures; i.e. 18 to 20psi is considered the top end for these devices.
Their name comes from the design of the rotating (air making) members of the blower. When disassembled, the rotating members, when viewed from either END, resemble a figure "8", with the loops of the 8 being the descriptive "LOBE". There are 2 such rotating members and they are designed so that they "fit together". They are displaced by 90 degrees so that the loop of one figure "8" fits into the side of the other figure "8". In this way, and due to the lobe design, this blower can produce high volumes of air at what is considered medium pressure.
Typical Applications include:
These blowers are used heavily in the material movement type of industry. For instance, animal feeds are transferred from the delivery truck to the storage bin at the farms by this type of blower. The high volume of air is able to move the feed very efficiently and more rapidly when compared to a bucket or screw conveyor. Also, when compared to the bucket or screw conveyor, there is significantly less moving parts and therefore maintenance is much lower.
They are also used in some aeration systems and operations where high volumes of air are used to dry product, such as in some sand plants.