Control Systems & PLC's

High Temperature

High Temperature Industrial Axial Ventilators

Northen Industrial Co. now offers high temperature construction on its axial fans.  There are a few steps of fan heat construction available: 200 F, 725 F, 800 F. High temperature inline fans are ideal for industrial oven and dryer exhaust systems where pressure requirements are minimal and compact light-weight designs are advantageous.

200 F High Temperature Duct Fans come with special heat bearings and a belt drive with increased safety factor.

650 F Tubeaxial Fan design involves special belt tunnel cooling system that induces a flow of cooler, ambient air through the belt well and inner tube, cooling the fan's internal components. Depending on temperature requirements, modifications include high-temperature alloy fan wheel, special drive components, and modifications to provide internal ambient air cooling.

Fans with ambient air cooling systems handling hot airstreams must have sufficient airflow and be kept in operation until airstream temperatures cool below 120 F to prevent damage to the fan unit. The Tubeaxial fan ambient air cooling system is only effective while fan is operating.

800 F Vaneaxial Fans are designed to operate continuously at temperatures to 800 deg. F, and include an auxiliary cooling fan that forces air through the bearing compartment and exits out through the insulated belt opening taking away excessive heat from the shaft and bearings. A high temperature shaft seal is also standard on this design.

Fans handling hot airstreams must have sufficient airflow and be kept in operation until airstream temperatures cool below 120 F to prevent damage to the fan unit. The Tubeaxial fan ambient air cooling system is only effective while fan is operating.

The Northen Industrial complete high temperature fans line now include:

- Operating up to 2200 F, centrifugal, axial and plug fan types;
- Pre-engineered and custom made fans for all types of applications with vaiety of impeller types and accessories;
- Northen Industrial engineers provide a professional advice and recommend a right fan for every application & oven / plenum design;
- The fan offering provides competitive replacement fans to Garden City, Lau, IGE, Alloy Fabricating fan models; repairs, re-build & balancing;
- Unique high temperature water-cooled motors for operation up to 2300 F;

in the two major types of high temperature fans - centrifugal and axial:

Centrifugal Wheels:

    * Multiblade forward curve wheel.  This type of wheel is usually specified where there is a necessity for large volumes of flow against low to medium static pressure requirements.  The forward curve blade is that it delivers the same volume of air as either the backward or radial blade wheel, at a lower fan speed, which is important due to wheel stresses at elevated temperatures.  This fan is the most common type used in all types of heat treatment operations except where a buildup of material on the blades could occur, as wheel unbalance would result.
    * Radial Blade, paddle wheel type fans.  This type of wheel is usually specified where there is a necessity for medium volumes of flow against medium to large static pressures. The paddle wheel is considered a self cleaning type of wheel.  It could be used where there are various materials or dust in the air stream.  Due to its structurally strong design, it is used in many heat treatment applications at very high temperatures where maximum fan longevity is desired.

Axial Blade Wheels:

    * The axial blade wheel is usually specified where there is a need for very large volumes of flows against low static pressure.   Axial wheel like the multi-blade forward curve type wheel could cause an axial fan to deliver different air volumes at the same static pressure, if the total pressure requirement of the fan system was underestimated. This type of fan is ideally suited where a large volume of flow is required with a minimum of duct work and is used extensively for small and large furnaces, such as aluminum annealing.

For additional information please refer to http://northernindustrialsupplycompany.com/products/industrialfan_blowers.html.

Oleg Cthetchel
Canadian process air systems developer
Northen Industrial Co.
http://northernindustrialsupplycompany.com/products/index.html
http://northernindustrialsupplycompany.com/manufacturers.html

About the Author

Oleg Cthetchel
Canadian process air systems developer
Northen Industrial Co.

http://northernindustrialsupplycompany.com/products/index.html

http://northernindustrialsupplycompany.com/manufacturers.html

In one cycle a heat engine absorbs 460 J from a high-temperature reservoir and expels 290 J ?

In one cycle a heat engine absorbs 460 J from a high-temperature reservoir and expels 290 J to a low-temperature reservoir. If the efficiency of this engine is 56% of the efficiency of a Carnot engine, what is the ratio of the low temperature to the high temperature in the Carnot engine?

Work done by the engine per cycle
W = Qh - Qc = 460J - 290J = 150J

efficiency of the engine
η = W/Qh = 150J/460J = 0.326

The engine operates at 56% of maximum attainable efficiency (carnot efficiency), i.e.
η = 0.56∙ηc

Hence:
ηc = η/0.56 = 0.326 / 0.56 = 0.582

Carnot efficiency is related to the cold temperature to hot temperature ratio as:
ηc = 1 - Tc/Th

Hence:
Tc/Th = 1 - ηc = 1 - 0.582 = 0.418

High Temperature Plastic