Trade.Information

Product Name: FORWARD CURVE

Product Description

High-Temperature Centrifugal Fans

Robinson FC fans are furnished with forward-curve wheels that are ideally suited for applications involving continuous operation at temperatures ranging from 70° F to 2,000° F. FC Series units are often constructed of special alloy materials for high-temperature service, but are used also for low-temperature operations. Other fan types designed and built by Robinson for high-temperature applications include axial flow, paddle wheel and radial blade series.
Performance Ratings

Robinson’s FC design is a result of thorough and exacting laboratory testing. Documented performance ratings from this work enable Robinson to provide equipment for quiet, efficient service over a broad performance range.

Performance ratings shown in this catalog were achieved through laboratory testing. These ratings were calculated on the basis of complete fan units, including wheel, casing and inlet section. Components are also furnished separately by Robinson, but the fan unit must be set up with wheel, shaft, casing, inlet and all other components in place to Robinson design specification to achieve rated performance.

ROBINSON FC SERIES FANS
Series
Temperature (Max.)
Class 300
300° F
Class 700
700° F<
Class 900
900° F
Class 1000
1000° F
Class 1300
1300° F
Class 1450
1450° F
Class 1550
1550° F
Class 1700
1700° F
Class 1800
1800° F
Class 2000 and above
*


*Consult factory

To View Forward Curve Fan Tables
Click here Literature Page and choose Bulletins/Brochures

Design Considerations
FC fans may be furnished with either non-insulated or fully insulated units.

FC fans are also offered with an insulated plug and non-insulated housing. In this type of construction, the non-insulated housing is usually mounted on the inside wall of the furnace or oven.

All Robinson FC Series are available in fan arrangements 1, 2, 4, 8 and 9. Flexibility in design also allows Robinson to offer both round and square plugs to accommodate a wide range of furnace requirements. Other capabilities include gas-tight designs.

For reliable, efficient service, Robinson has always stressed the importance of preventive maintenance. Fan casings are therefore designed with either plug-type housings or split housings for accessibility to the wheel for service and/or removal.
Design Considerations

FC fans may be furnished with either non-insulated or fully insulated units.

FC fans are also offered with an insulated plug and non-insulated housing. In this type of construction, the non-insulated housing is usually mounted on the inside wall of the furnace or oven.

All Robinson FC Series are available in fan arrangements 1, 2, 4, 8 and 9. Flexibility in design also allows Robinson to offer both round and square plugs to accommodate a wide range of furnace requirements. Other capabilities include gas-tight designs.

For reliable, efficient service, Robinson has always stressed the importance of preventive maintenance. Fan casings are therefore designed with either plug-type housings or split housings for accessibility to the wheel for service and/or removal.

Quality Control

Dye penetrant testing, ultrasonic testing, vibration analysis, x-ray testing and, in some cases, magnetic particle inspection, are utilized to ensure that FC Series fans meet Robinson’s stringent quality control requirements. Other steps taken to ensure long fan life include dynamic balancing of the wheel and shaft assembly on independent, computerized equipment. Full-scale mechanical testing is performed on the assembled FC unit (when possible) prior to shipment.

Fan Repair and Field Service

Robinson field service representatives are available for troubleshooting, field balancing and diagnostic inspection of fans and other types of rotating equipment. These personnel supervise certain on-site repairs or, if necessary, determine whether the unit must be factory-repaired.

Robinson repairs and rebuilds FC units as well as all types of industrial fans, regardless of original manufacturer. In addition to fan repair as a cost-saving alternative, Robinson redesigns and upgrades existing air-moving equipment to increase capacity and improve efficiency.

Robinson FC Drive Arrangements

Arrangement 1
FC fan arrangement for either v-belt or direct drive, depending on customer specifications.
· Sizes: 18 in – 73 in.
· Temperature range: 70° F – 2,000° F

Arrangement 2
FC fan arrangement for attachment of bearing base to plug, typically utilized in mounting fan unit to sidewall or roof of furnace or oven. Fan may be belt-driven or direct connected. This design can be furnished with either flange or pillow-block bearings.
· Sizes: 18 in – 73 in.
· Temperature range: 70° F – 2,000° F

Arrangement 4
FC fan arrangement for mounting of fan rotor directly to motor shaft.
· Sizes: 18 in – 30 in.
· Temperature range: 70° F – 180° F

Arrangement 8
FC fan arrangement for direct connected service. Robinson unit includes motor base in addition to standard bearing base.
· Sizes: 18 in – 73 in.
· Temperature range: 70° F – 2,000° F


Arrangement 9
FC fan arrangement for v-belt with bearing base to receive direct motor and adjustable motor base for proper drive tension.
· Sizes: 18 in – 73 in.
· Temperature range: 70° F – 2,000° F

FC Fan Housing Designs

This section includes housing designs for Robinson FC fans. Design of insulated plugs allows removal of wheel, shaft and bearing assembly without affecting field or housing insulation. When the fan is insulated without the plug assembly, the wheel and shaft are removed through the inlet side of the housing. Split-housing designs are also available for any size. Split housings may be required on fans larger than 60" size.

1. Non-insulated Fan Assembly
Maximum temperature: 700° F
Horizontal mount: Arrangements 1, 8 or 9
Vertical mount: Arrangement 2

2. Insulated Plug/Non-insulated Housing
Maximum temperature: 2000° F
Horizontal mount: Arrangements 1, 8 or 9
Insulated plug contains 5-1/4" insulation.

3. Complete Insulated Fan Assembly
Maximum temperature: 2000° F
Horizontal mount: Arrangements 1, 8 or 9
Vertical mount: Arrangement 2
Insulated plug contains 5-1/4" insulation.

4. Insulated Plug
Maximum temperature: 2000° F
Horizontal mount: Arrangements 1, 8 or 9
Vertical mount: Arrangement 2
Insulated plug contains 5-1/4" insulation.

5. Insulated Plug/Non-insulated Housing
Maximum temperature: 2000° F
Horizontal mount: Arrangements 1, 8 or 9
Vertical mount: Arrangement 2
Insulated plug contains 5-1/4" insulation.

Fan housing is mounted on internal surface of oven or furnace. Housing can be furnished with tabs (A) for mounting inside of furnace or oven surface, or with a sleeve and flange (B). Flange is field-welded to sleeve.

FC Fan Housing Construction

Designed for efficient service, Robinson housings are fabricated from a wide range of materials to meet application requirements of temperature and/or corrosion. Housings feature welded construction, and fabrication tolerances are closely monitored.

In situations involving fan-related expansion, Robinson FC housing units are designed to consider thermal expansion. Attached inlet and outlet duct connections must allow for expansion. Depending on various factors, this expansion allowance may be provided by the use of slip joints or fabricated expansion joints. Factors that affect thermal expansion design include fan size, attached duct location, and design and type of system; i.e., whether or not it is gas-tight. Expansion joints are offered by Robinson as optional items or may be provided by other suppliers.

FC fan housings are furnished by Robinson in both non-insulated or fully insulated construction. Plug-type or split housings are available for both non-insulated and fully insulated designs. Plugs are constructed to both round or square designs, but round plug units are furnished by Robinson unless otherwise specified.

As required, housing may be furnished separately for mounting on the inside surface of the furnace/oven or kiln. In this situation, they are available with or without a sleeve, depending on customer preference.

Fan equipment built for explosive, gas-tight or highly corrosive applications requires special construction features. For explosive service, these include nonferrous construction and grounding of components. Gas-related applications require gas-tight mechanical seals. Water-cooled shafts and water pad are often used to dissipate heat buildup.

Robinson has extensive experience in building fans for highly corrosive environments. A wide range of alloys and special metals are used in the construction of FC units for this type of service. A special surface treatment is also offered by Robinson for high-temperature fans used in certain corrosive conditions.

Wheels

FC wheels are carefully engineered by Robinson to provide optimum performance while maintaining the integrity necessary for demanding high-temperature service requirements.

Finite element stress analysis procedures are used to design the wheels for a wide range of size, temperature and speed requirements. From this information, selections are made regarding types of materials to be utilized in wheel construction as well as thickness of the materials.

In the engineering data section of this bulletin are listed limiting speeds for fan size and temperature conditions.
Requirements falling outside of these parameters are also possible, pending approval of Robinson’s engineering staff.

Shafts

Shafting is solid and machined to meet applicable bearing tolerance and wheel-fit tolerance requirements. Alloy shafts are utilized in high-temperature situations.

Set-screw and key method is used for standard wheel and shaft attachments. A weld wheel-to-shaft attachment design is sometimes recommended by Robinson if certain temperature, speed, size and mounting arrangements dictate the need for it. Shafts are furnished with heat flingers to protect fan bearings as required.

Bearings

Depending on equipment size, speed and temperature, either ball, roller or sleeve bearings are used in FC fan construction. Either heavy-duty pillow-block or flanged-type bearings are furnished by Robinson, depending on the application. Grease is the standard lubrication for ball and roller bearings.

Automatic grease systems are also available for bearing lubrication. For oil-lubricated bearings, static oil is the standard lubricant, although circulating oil and oil mist systems are also available.

Shaft Seals

For applications requiring shaft seals, standard gasket seals are normally furnished with materials to suit the application.

Other types of specialized seals are available for more demanding service, including gas-tight applications. Shown is a positive packing gland of alloy construction with adjustable features.

Accessories

Optional accessories and design modifications include discharge drains, inlet and outlet flanges, inspection doors, discharge dampers and insulation studs. These accessories are standard on some Robinson FC models, depending on the application and type of service, and they may also be recommended by Robinson engineers for fans used in certain conditions.

Repair and Rebuilding – A Cost-Effective Alternative

The knowledge and experience gained by working with a wide range of standard and high-grade alloys enables Robinson to offer an excellent high-temperature repair and rebuilding service. Robinson also redesigns and upgrades existing fan equipment for increased capacity and efficiency.

Robinson is particularly equipped to handle reoccurring high-temperature fan problems, regardless of original manufacturer. In addition to high-temperature expertise and special fabrication capabilities, Robinson utilizes diagnostic and nondestructive testing procedures to effectively eliminate problems often encountered in the demanding high-temperature area.

Recognizing the effect of downtime on production, Robinson expedites repair projects to get the fan equipment back into production as soon as possible. In fan rebuilding, original components, such as the shaft and hub, are re-used when possible to save time and money.

Facilities in both Zelienople, Pa ., and Lakeland, Fla ., have the proper equipment for high-temperature fan repair and rebuilding. Robinson also features large-capacity electronic dynamic balancing equipment at both locations. Robinson balances fan rotating equipment up to 180 inches diameter and/or 100,000 pounds to 30 foot centers. All repaired or rebuilt fans are precision balanced prior to shipment.

Should your high-temperature fan show signs of wear, corrosion or unbalance, or if it requires constant maintenance, contact Robinson to arrange a visit by expert field service representatives. Catching the problem before it becomes critical and repairing fan equipment during the shutdown will save time and money.

Centrifugal Fans for High-Temperature Recirculation

Air Performance and Sound Testing
Research engineers and technicians use modern instrumentation to ensure accurate test results in accordance with strict test standards.

Mechanical and Dynamic Testing
Robinson engineers can utilize strain gauge technology to compare actual operating stresses of rotating fan wheels to theoretical finite element analysis.

Nondestructive Testing
The emphasis on quality at Robinson is backed by expert workmanship and a thorough quality control program. Nondestructive testing techniques used by Robinson include:

Computer finite element stress analysis
Magnetic particle inspection
Ultrasonic testing
Dye-penetrant testing
Radiographic (X-ray) testing
Vibrational resonance testing using dual-channel real-time analyzer
Dynamic strain gauge testing
Other Special Alloy Fans for High-Temperature and Corrosive Applications

Robinson manufactures all types of axial flow , radial bladed or forward curve fans , either insulated or non-insulated. Special alloy fans are custom designed and constructed to meet your furnace atmosphere, high-temperature and corrosive applications.

Years of experience enable Robinson to recommend special features needed for your particular application. These may include horizontal or vertical shaft applications, housed and unhoused units, insulated or non-insulated components, or any combination thereof.

High-Temperature Axial Flow
Bulletin 6310

Arranged for vertical mounting, this unit features a flange motor mounting that provides uniform load distribution. View of this axial flow fan shows the accessibility of the bearings.

Arranged for horizontal and vertical mounting, this unit features a conventional foot-mounted motor with slide rails arranged for V-belt drive. This view of the axial flow fan shows the overall quality of workmanship performed at Robinson.

High-Temperature Forward Curve
Bulletin 6320

This 36-1/2" forward curve fan features full insulation and a split housing for easy access to the wheel for servicing and/or inspection.

This Robinson recirculating fan is furnished with an alloy wheel and drive-side plug.

High-Temperature PW
Bulletin 6330

50-1/2" PW fan features “Rob-insulated” casing, alloy wheel and shaft. Operating temperatures up to 2000° F.

A plug assembly illustrating a typical “high-temperature” impeller with corresponding shaft and bearings. “Factory” insulated plug furnished on all high-temperature fans for temperatures over 1000° F.

Company Details

Robinson Industries Inc., based in Zelienople, PA, is the leading manufacturer of custom-engineered and custom-built industrial fans in North America, with sales extending worldwide. With four U.S. locations, Robinson Industries works in a... more