Centrix Help Online

Centrix is a centrifugal fan selection program that enables a fan manufacturer to select, design, cost and quote fans for applications.

Version 3.5 with CAD drawings :

New Feature : Project file saving and loading.

Save the current status of your fan selection project for later retrieving!

Features :

Selects fans from a range of designs to suit a volume and pressure.
Plots Performance Curves.
Calculates noise levels.
Designs Silencers.
Mechanically designs and calculates stresses.
Produces detail and arrangement drawings.
Many drawings and details can be saved as Autocad dwg files.
Produces cutting profiles for the main components.
Estimates the costs, areas and weights.
Produces a handing specific General Arrangement drawing.
Produces a quotation document.

Centrix Does not :

Design the aerodynamic proportions. The aerodynamic proportions must be known and entered into the Centrix database. Centrix uses these proportions and designs a range of fans by manipulating the fan laws.

Full List of Software Features :

This program does in a couple of minutes what an experienced fan engineer would take days to design and cost!

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Aerodynamic designs and a nominal range of sizes are entered into the program by Raksolutions. These designs are usually provided by the purchaser. Raksolutions can provide fan aerodynamic design criteria if required.

The aerodynamic design is what gives a particular fan its volume, pressure and power characteristics. A single aerodynamic design can meet any volume and pressure that you can think of but the size or speed may not be practical due to mechanical limitations (size outside the range or speed outside the range).

The mechanical design must consider :
a) Impeller stresses - dependent on speed, temperature, thickness and material selection.
b) Casing thickness - dependent upon fan diameter, pressure and noise breakout.
c) Shaft design - dependent upon impeller weight, belt or coupling load, motor torque, fan arrangement, temperature etc.
d) Bearing selection - dependent on shaft size and loads and rpm.
c) Pedestal design - dependent on fan diameter, power and rpm.

Centrix selects a standard size of aerodynamic design and calculates all the above factors (and more). For example a particular fan selection may not be suitable for belt drive because the bearings can't take the load and larger bearings can't be used because of rpm limitations. However the same fan could be direct coupled arrangement 8 with no problems due to the much lower load. Also Arrangement 7 shaft and bearings can often be used when an arrangement 8 shaft can't.

Shaft critical speed is easily calculated by Centrix. If you have ever been unable to balance a fan in service and it vibrates like crazy then you probably have a shaft critical speed problem. Did you know that in overhung fans (arrangements 1, 2, 8, 9) the shorter the distance between the bearings the higher the critical speed is and the larger the impeller overhang from the inboard bearing the lower the critical speed is. The shaft critical speed should always be higher than the fan running speed by a margin of at least 25%. Centrix gives a warning when the critical speed is below 35% margin.

Ever had a start up problem? Centrix calculates the starting time and gives warnings alerting you to investigate the use of a larger motor or higher staring torque. Need a speed versus torque curve? Get one from Centrix with dampers open or closed.

Centrix enables the user of the software to interact with the program and mechanically design the fan. From this point of view it is invaluable as a design aid and also as a training tool.

Your Company Logo is added to the program by Raksolutions and will appear on all quotation drawings and documents.

The program contains the following main features:

• Quotation database.

• Fan selection and curve plotting including total and static efficiencies and calculated inlet vane / damper curves.

• Automatic calculation of the gas density.

• High temperature selection and design features are provided for temperatures up to 650 Degrees Celsius.

• Noise calculations. Internal Sound power level, inlet and outlet pressure level and breakout noise are all calculated.

• Silencer design, selection and costing.

• Impeller stressing (static 2 dimensional), areas, weights, inertias, material and labour costs.

• D.O.L starting time and torque speed curves with closed or open damper.

• Arrangements 1, 2, 3, 4, 7, 8 and 9 are supported. (Arrangement 2 is used for Plug fan designs)

• Fan shaft design for over hung and centre hung arrangements and shaft detail drawing.

• Roller bearing, Carb bearing and ball bearing selection, design life, minimum loads and costing.

• Static component design (thickness, stiffener patterns and stiffener size), areas, weights and labour hours for pedestal, casing, inlet box, inlet damper, outlet damper, inlet vanes.

• Damper and Inlet Vane operating torque.

• Damper detail dimension drawing including selection of damper spindle diameter (calculation of deflection and stress) and bearing costs.

• Pedestal manufacturing drawings for arrangements 1, 8 and 9.

• Arrangement 9 stability calculation.

• Belt centres calculation with slide rail positioning features for true belt centres and tensioning allowance.

• Costing database which allows the user to adjust hours, rates and mark up factors for each individual quote.

• Materials and proprietory equipment database for storing motor dimensions and prices, bearing prices, plate and bar prices etc.

• Calculation of paint costs for various paint schemes.

• Dimension sketch of the fan for the most common fan arrangements including channel base detail drawing for arrangement 1 fans.

• Database maintenance facilities to enable users to keep their costs and rates up to date as well as tune the labour hours to suit different manufacturing techniques.

• Quotation technical schedule document with full editing features.

• Saving and retrieval of projects for later editing.