Effective Use of Infrared Heating for Wire & Cable Applications

©2010 Glenro, Inc.

Wire Expo 2010 Milwaukee 1

Presentation Overview • How it works – Effective Use of Infrared Theory • What makes it work – Effective Equipment Choices • Where it works – Effective Heating Solutions

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Presentation Overview 2

What is Infrared Energy?

• All objects above absolute zero (- 460° F) emit infrared radiation. The infrared portion of the electromagnetic spectrum is found between visible light and short radio waves. Infrared radiation is emitted at wavelengths between 0.72 and 1000 microns. However, only the 1 – 10 micron wavelength band is utilized in the vast majority of industrial heating applications (1% of the range).

Electromagnetic Spectrum - Useful Infrared Region

0.72 - 1 .5 µm 1.5 - 5.6 µm 5.6 - 10 µm Short Wave Medium Wave Long Wave •

Figure 1: Useful Infrared Spectrum for Industrial Heating Applications

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Infrared Spectrum 3

Infrared Radiation Heat Transfer • Absorbed by the product • Transmitted through the product • Reflected away from the product

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Infrared Heat Transfer 4

Useful Equation

• Wein’s Displacement Law: µm = C/T • – µm = Wavelength of most energetic radiation – T = Absolute Source Temperature – C = 5200 when applied to absolute temperature in Fahrenheit (°F + 460) – C = 2900 when applied to absolute temperature in Centigrade (°C = 273) • This equation will calculate the most energetic or peak operating wavelength of the radiant source when operated at a specific temperature. • If source temperature = 1500 °F, then µm = 5200/(460 + 1500) = 2.7

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Useful Equations 5

One Last Equation

•

Stefan-Boltzmann Law: W = Eσ (T s 4 - T t 4 )

– E = Emissivity Factor (1 for Black Body) – T s – T t = Absolute Temperature of Source = Absolute Temperature of Target – σ = Stefan – Boltzmann Constant = 3.5 x 10 – W= Watts/in 2 -12 (° F + 460) 4 Energy Density or Flux Transferred • This equation shows how small changes in source temperature relate to much larger increases in energy transferred. The implication of this Law reveals that a practical limit is quickly reached with respect to industrial heating applications for the kinds of products and materials under consideration for this presentation.

• As an example, if the source temperature is increased 10% from 1500° F to 1650° F, the energy transferred or flux increases from 51 W/in 2 to 69 W/in 2 or 35%.

. ©2010 Glenro, Inc Useful Equations 6

Understanding Target Absorption

• 2.9 µm or 1300° F – One place to run • 6.0 µm or 400° F – Another place to run • Target Temp = 250° F • Using Stefan-Boltzmann – 2.9 µm ~ 32 Watts/in 2 – 6.0 µm ~ 2 Watts/in 2 ©2010 Glenro, Inc.

Wavelength vs Temperature 7

Practical Overview of Theory

•

What you should know…

– Infrared energy delivered to a product by an industrial heater encompasses a range of wavelengths and temperatures – The physical characteristics of your product will determine the rate at which infrared energy is effectively absorbed.

– Almost all products are highly absorptive at more than one wavelength.

•

The Right Approach – Solve for Watt Density & Dwell Time

– The key to successfully incorporating infrared energy on a product manufacturing line relates more to watt density and dwell time and less to whether the infrared heater is operating at the peak absorption wavelength of the product. – How aggressively can I heat my product before something bad happens? – How much time is required to transfer the energy I need to get my work done?

– These are the questions to answer that will serve you well and ultimately help you produce an acceptable product. ©2010 Glenro, Inc.

Practical Overview of Theory 8

What Makes it Work • Infrared Heater Characteristics

Characteristic

Radiant Efficiency Mechanical Strength Heat Up/Cool Down Emitter Temperature Color Sensitivity Wavelength Range Power Density

Short Wave

Quartz Lamp (T-3) High to Medium Low Fast 4000 ° F High 1 to 1.5 µm 100 W/linear inch

Medium to Long Wave

Quartz Cylinder Flat Panel High High Slow 1500 ° F Low 2.5 to 5 µm 10 W/in 2 High to Medium Medium Medium 1800 ° F Low 2.3 to 5 µm 30 W/in 2 ©2010 Glenro, Inc.

Infrared Heater Characteristics 9

Infrared Heater Illustrations

• • • • • • • High Watt Density Quartz Lamp Emitters with Reflectors Fast Response Horizontal or Vertical Water or Air Cooling Required Single Pass Product Centerline Crucial

Short Wave Infrared Heater

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Short Wave Infrared Heater 10

Infrared Heater Illustrations

• • • • • • • • • Low Watt Density Resistive Wire Element Emitter Quartz Core Slow Response Horizontal or Vertical Solid Core/Split Case/Slotted Opening Insulated Construction Single Pass Typical Rugged

Medium Wave Quartz Cylinder Radround® Heater

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Medium to Long Wave Infrared Heater 11

Infrared Heater Illustrations

• • • • • • Medium Watt Density Open Resistive Wire Element Construction Medium Response Horizontal or Vertical Insulated Construction Single or Multiple Pass Capable

Medium Wave Radplane ® Heater

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Medium to Long Wave Infrared Heater 12

Controlling Technologies

• Open Loop Control • Semi-Open Loop Control • Closed Loop Control One of IR heating’s biggest advantages over other methods of heat transfer is its’ ability to transfer significant heat energy in a relative small space. This concentrated energy needs to be controlled accurately for repeatable process results. A radiant heater realizes its full potential for a given application only when the proper controls are utilized. The method of control relates the heater to the application.

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Controlling Technologies 13

Open Loop Control

• Open Loop Control: These circuits do not use heater or work (product) temperature as a control factor. Instead, control is by manually varying the heater supply voltage. Since there is no corrective feedback from heater temperature or work temperature, open loop control cannot be used where close control of the process is important.

• Heater Element vs Product Temperature Control

:

Where either the temperature of the heater or of the work (product) must be the controlling factor, a temperature sensing device must be used. To control by heater temperature, an embedded thermocouple is mounted in a fixed position relative to the heating element. To control by work (product) temperature, a radiation pyrometer or optical pyrometer is used. Each of these devices can be connected in a control loop.

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Open Loop Control 14

Semi-Open Loop Control

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Semi-Open Loop Control 15

Closed Loop Control

Response Time: Heater response is critical

to making closed loop feedback control work.

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Closed Loop Control 16

Where it Works

•

Preheat

– PVC and steel conduit before cutting – Wire prior to extrusion – Conductor with insulating tape prior to jacket extrusion •

Heat

– FEP extrusion on wire – Heat-Shrink tubing made of Teflon on catheters – Heat-Shrink tubing – Singe and Heat-Clean fiberglass sleeving prior to coating – Gel & Fuse PVC coatings on fiberglass sleeving •

Cure

– Extruded PVC and silicone tubing/jackets •

Sinter

– Extruded tubing made of Teflon® – PTFE cable wrap on multiconductor wire – Fluoropolymer resins on high temperature wire ©2010 Glenro, Inc.

Applications 17

Where it Works

•

Dry

– Dry and Cure striping and nomenclature ink on insulated wire – Dry and Cure color coding inks on fiber optics – Dry and Cure saturants (latex, acrylic, urethane) on fiberglass sleeving (dielectric sleeving) – Water-based UV curable coatings on fiberglass sleeving prior to UV cure – Lacquer or resin on braided magnetic wire – Graphite coatings on spark plug wire – Dry and Sinter PTFE dispersion coatings on glass braided tubing made of Teflon (automotive fuel lines) – Extruded water-based adhesive on multiple wire ends – Residual moisture prior to outer jacket extrusion ©2010 Glenro, Inc.

Applications 18

Evaluating Applications

• What anyone needs to know… – Process Objective (preheat/predry/dry/heat/cure/sinter) – Product Weight (per linear foot) – Product Composition (materials of construction) – Process Line Speed – Target Entering Temperature – Target Exiting Temperature – Available Space (up/down/all-around) – Access/Threading/Maintenance – Operating Voltage ©2010 Glenro, Inc.

Evaluating Applications 19

System Illustrations

• Heat Source: Solid Radround® • Heated Length: 42” • Features: – Support Frame – End Closures – Integral Semi-Open Loop Temperature Control System

Preheat Fine Gauge & Braided Wire prior to Teflon® Extrusion

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System Illustrations 20

System Illustrations

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Dry PTFE Release Agent on Bare Stranded Tin/Copper Wire in line with Extruder

• Heat Source: Split-case Radround® • Heated Length: 126” • Features: – Support Frame – Auto-Retraction – Semi-Open Loop Temperature Control System System Illustrations 21

System Illustrations

Cure Extruded Tubing or Jacket on Wire/Cable

• Heat Source: Short Wave Infrared Heater • Heated Length: 76” • Features: – Support Frame – Capstan Wheel – Integral Open Loop Control System ©2010 Glenro, Inc.

System Illustrations 22

System Illustrations

• Heat Source: Split-case Radround® • Heated Length: 84” • Features: – Support Frame – End Closures/Product Support – Automated Dual Retraction – Portable – Integral Semi-Open Loop Temperature Control System

Cure Solvent Based Resin Impregnated Braid on Copper (Magnetic) Wire

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System Illustrations 23

System Illustrations

Vertical Multiple-end or Multi-pass Medium Wave Infrared System

• Heat Source: Open Element Hi-Temp Heat Tunnel • Heated Length: 126” ©2010 Glenro, Inc.

System Illustrations 24

System Illustrations

Horizontal Multiple-end or Multi-pass Medium Wave Infrared System

• Heat Source: Open Element Hi-Temp Heat Tunnel • Heated Length: 42” ©2010 Glenro, Inc.

System Illustrations 25

Conclusions

• Infrared is a viable industrial heating solution for many wire and cable applications, if properly designed and controlled • Don’t get too caught up in the theory of it all – it is easy to test run the technology to determine viability, both technically and economically • Typical returns on the investment are attractive and periods short if the installation results in increased product revenue streams • Most equipment solutions for wire and cable applications are electrically heated, thus, you are not adding to an existing carbon footprint • Go to

www.glenro.com

contact us to learn more, sign up for our newsletters or to ©2010 Glenro, Inc.

Conclusions 26