Custom Electric Heating Elements for Aerospace, Satellites, and Space Exploration

BCE applies specialized know-how in top level design and production to supply electrical heating technologies for applications in the fields of aerospace, satellite communications and space exploration. 

Providing electric heaters to the aerospace, satellite communications, and space exploration industries require pristine accuracy and conformance to exacting specifications. Heating elements must be designed to handle extremes in temperatures, shock and vibration, comply with exacting weight and size requirements, and be capable of operating in vacuum environments - all while still providing fail-proof performance.

BCE has decades of engineering and design experience in developing custom electrical heating elements for these industries. BCE's expertise has been called upon to solve many difficult application challenges unique to these applications, including viscosity control, condensation prevention, freeze protection, as well as air and gas heating.

BCE controls the entire manufacturing cycle including design, production and testing. Their understanding of electric heating technology, and the innovation accumulated along the way, is built upon decades of working closely with customers, meeting their critical requirements. Components and materials are carefully selected according to the customers’ exact specifications, many time turning out to be more than just the heating element itself. Products can be supplied as full assemblies complete with mechanical components, connectors, and sensors with batch sizes from a single piece to large volumes.

Contact BCE with any challenging electrical heating application in the aerospace, satellite communications, and space exploration field. You'll be glad you did.

BCE
https://bcemfg.com
510-274-1990

High Temp Heater Chuck – 200mm

A semiconductor equipment company in the Atomic Layer Deposition (ALD) market approached BCE in need of a custom high temperature heater solution.  Their application involved a thin-film deposition using a sequence of various chemical processes.  Repeating these processes results in a thin film being slowly deposited. 

SCOPE

High Temperature Heater Chuck needed to satisfy the following:

• Temperature <700°C   
• Internal element must be able to withstand higher than 700°C
• Thermal break between flange and base reducing heat transfer to flange area 
• 316 Stainless steel base, sleeve, and flange must pass all required vacuum specifications
• 240Volt 1450Watt
• Built-in thermocouple type “K” inside internal element grounded with RF screening 

OUTCOME

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BCE produced a highly effective high temperature heater with exceptional uniformity.  The design was able to compress the internal element enough to allow for optimal temperature transfer.  The weld around the outside periphery of the base plate and the (3) lift–pin-hole-standoffs were essential in the design for vacuum integrity, ramp rate, and temperature stability. 

For more information, contact BCE. Call them at 510-274-1990 or visit their web site at https://bcemfg.com.

Electric Heating Elements: Cartridge Heaters

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Cartridge Heater Basics

Cartridge heaters are cylindrical in shape, consisting of an element made of resistance wire wound around a ceramic core. Within a metal sheath tube, the wound core is precisely centered and surrounded by granular magnesium oxide material. This isolates the resistance element from the tube electrically and provides a heat transfer medium to the sheath tube. At one end are electrical terminations. In order to enhance internal heat transfer and electrical insulation characteristics, higher performance, longer-lived cartridge heaters are swaged (a rotary hammer compacting process). Swaging compacts and densifies the granular insulating material, improving its thermal conductivity. Cartridge heaters are commonly used and are produced in a broad range of lengths, diameters, wattages, watt densities, lead agreements, and optional internal sensors.

Cartridge Heater Applications

Specialized Cartridge Heater (BCE)

The following equipment utilizes cartridge heaters: chromatography equipment; medical laboratory equipment, including chemistry analyzers; plastic molds and runners; platens; barrels on extrusion equipment; hot melt glue systems; packaging seal bars; labeling and marking systems; food-warming equipment and steamers; autoclaves; ovens; photographic processing equipment.

Cartridge heaters are capable of operating at elevated temperature as well as high watt density, but care must be taken to apply cartridge heaters at appropriate watt density and sheath temperature levels.

Temperature Capability

A maximum of 1600°F (870°C) sheath temperature is recommended.

Watt Density Capability

A maximum of 400 W/in. and higher under special conditions.  As a rule, cartridge heaters can operate at 1600°F at 40W/in.

Heater Life

Operating at 1600°F internal temperature with modest cycling and with the proper hole fit, a properly designed and constructed cartridge heater will provide approximately a one-year life.

Voltage

Usually 120/240V, with 480V and custom voltages requiring special design or sizing considerations.

Thermal Response/Application

Cartridge heater's thermal response is dependent on conductive heat transfer in most applications.  Optimum conduction requires close fit between the heater and the work to be heated. As heater looseness increases, watt density must be decreased accordingly, to prevent internal overheating. Watt densities of liquid-immersion cartridge heaters vary according to the liquid's viscosity and heat capacity.  When heating liquids, care must be taken to prevent "film boiling" where vapor bubbles create a thermal insulating effect and raise the heaters internal temperatures.

Heater Efficiency

Cartridge heaters are 100% efficient when immersed.

For more information about electric heating elements, contact BCE by calling 510-274-1990 or by visiting https://bcemfg.com.

Electric Heating Elements and Electrical Feedthroughs for OEM Applications

BCE offers OEM (original equipment manufacturers) custom electric heaters, feedthroughs and BCE OEM customers benefit from decades of thermal design and applications experience. With a reputation for fast prototyping, quick turnaround for pre-production runs, and an eye for cost-effective design, equipment manufacturers quickly discover that find BCE is a long-term, highly valued supplier/partner.
sensors.

OEM Equipment Markets

• Aerospace
• Semiconductor
• Analytical Instruments
• Photovoltaic
• Medical Equipment
• Plastics Processing
• Foodservice Equipment
• Packaging

OEM Electric Heaters & Feedthroughs: Price, Delivery, Performance

Basic Wattage Requirement Calculations for Metals, Non-metals, and Gases

Accurately heating various materials such as metals, non-metals, liquids and gases is complex. There are many variables to consider. Material properties such as density, thermal conductivity, specific heat and time all must be known to calculate a correct wattage value. Phase change (solid to liquid, liquid to gas) requires additional calculations to account for latent heat of vaporization and latent heat of fusion.

BCE, a manufacturer of custom heating elements and thermal systems, has a page on their website providing basic wattage requirement calculations for your reference. These calculations will assist you in determining the amount of power your heater will require, but it is strongly suggested you consult with a heater application expert before designing, specifying, or purchasing. Their expertise and knowledge will assure a safe, efficient, and economical heating solution.

Visit the BCE Basic Wattage Calculation page.

Clean Gas and Liquid Stream Heating

Clean gas and liquid heater
(BCE Mini Clean Flow)

As demand for purity increases throughout the medical, analytical, and semiconductor industries, equipment manufacturers continuously require new tools to reach the next technology threshold. In these industries electric heating applications for clean gases and liquids abound. Just a few examples are; clean air circulation, nitrogen heating, product drying, dehumidification, analytical instrument sample prep, incubation, DI water heating, solvent removal, wafer drying and processing.

High purity gas and liquid heating is challenging. Heater designs have to address problems and concerns involving contamination, thermal efficiency, electrical isolation, controllability, size, and packaging. Gas and liquid heating applications can vary dramatically. Some applications are very difficult to control and size is always a concern. One of the toughest issues to overcome is the seemingly mutually exclusive requirement for smaller size and higher power.

General diagram of "clean flow" heater.

Driven by innovation and competition, the need for hotter, cleaner, smaller and more efficient electric heaters is unceasing. One type of heater known as the "clean flow" has broad adaptability to many clean gas and liquid heating needs. It utilizes an internal heating element isolated from the process flow chamber, both electrically and physically. Best described as a "mini circulation heater", the heater's flow chamber, with inlet and outlet connections, completely protects the clean gas or liquid from external exposure and contamination.  The internal heating element can run at fairly high watt densities to accommodate fast changing flow rates, while still maintaining a compact and efficient package.  Internal RTDs or thermocouples can be incorporated to monitor temperature closely, or to protect the heater from over-temperature.

If you have questions about electrically heating clean gases or liquids, contact BCE by either visiting https://bcemfg.com or by calling (510) 274-1990.

Custom Heating Elements and Thermal System Design

The design and manufacture of custom heating elements and thermal systems are a specialty of BCE Inc. (Belilove Company-Engineers), a Hayward, California-based company that has served the aerospace, semiconductor, analytical and medical equipment industries for more than 25 years.

As both a manufacturer and integrator of components, BCE offers custom electrical heaters, sensors, and controls as discrete components, or as part of a larger, value added thermal system.

Visit https://bcemfg.com or call 510-274-199 for more information.

Understanding Ohms Law

Ohms Law states that I = V / R. When I is measured in amperes and V in volts, the units of the electrical resistance R are known as ohms. A voltage of 1 volt, faced with a resistance of one ohm, will drive through it a current of one ampere.

When applying Ohms Law to electric heating elements, the following statements explain the relationships between power (watts), current (amps) and voltage.

• Watts = Volts x Amps
• Amps  = Watts / Volts 
• Volts = Watts / Amps 

The following video provides a deeper understanding of Ohms Law.

Electric Heating Element Application and Engineering Reference Guide

Applying and specifying electric heating elements can be complicated. Make the job easier by downloading our handy reference guide (courtesy of Backer Hotwatt). The reference guide includes many of the electrical, mechanical, and physical properties you'll need to know when calculating wattage, evaluating maximum watt densities, and selecting proper heater placement.

CONTENTS

• Wattage Calculation Formulas and Examples
• Properties of Metals
• Properties of Non-Metallic Solids
• Properties of Liquids and Gases
• Suggested Watt Densities
• Estimates of Wattage Required
• GuideforHeatLosses
• Suggested Sheath Materials
• Thermal Systems
• Installation
• Ohms Law
• Wiring Diagrams
• Mathematical Conversions
• Wire, Cable and Current Capacities
• Wire Gage Data
• Pipe Sizes and Threads
• Resistance Wire - Current vs. Temperature

Get your copy of the guide here.

Contact BCE for any electric heating element or thermal system requirement. Visit them at https://www.belilove.com or call (510) 274-1990.

High-Temperature Vacuum Feedthrough Assembly with Multi-Thermocouples and Electric Heater with Thermowell

Multi-Thermocouple and Heater Feedthrough

Introducing the latest in temperature sensing and heating technology. BCE’s High-Temp Vacuum thermowell assembly is a robust, laser-welded design integrating the sensing capabilities of type K thermocouples. These thermocouples can be easily mounted to any part in a vacuum chamber by the means of shims with mounting holes. Furthermore, they can be positioned with ease due to integrated compression fittings, which also allow for easy replacement of the thermocouples should the need arise. A 304 Stainless Steel flange achieves a vacuum tight seal into any vacuum or degassing chamber port and there is virtually no outgassing, enhancing performance in high-vacuum environments. Moreover, a cartridge heater embedded inside an Aluminum 6061 thermowell allows for uniform and efficient heating of the chamber. BCE’s Hi-Temp Vacuum Thermowell Assembly: breaking barriers in high vacuum applications.

Specifications

• CAD modeling and Engineering Design Consultation 
• High-Vacuum compatible up to 10-7 Torr 
• Max Operating Temperature can be up to 400°C (dependent on lead insulation material) 
• 10X thermocouples, Type K, Grounded, with shims and mounting holes (multiple options available) 
• 450W, 240V embedded cartridge heater (multiple options available) 
• 10X SS316 compression fittings (multiple options available) 
• AL6061 thermowell 
• SS304 Isolating Flange with dovetail O-ring groove 

Polyimide Thermofoil Heaters Used for Space Applications

Thermofoil heaters of an all polyimide (adhesive-less) construction are used for high reliability space applications. They are ideal for extreme temperature fluctuations and have high tear and tensile strength. The specifications for the design and manufacture of these heaters are rigidly controlled, and rightly so. These heaters often perform critical heating application on satellites and other space craft.

Construction

A polyimide (Kapton) is used as the heater base material, also known as the substrate or mounting surface. A second polyimide layer over the heating element provides a protective enclosure.

Heater Element

The heating element is made of a Ni-600 Inconel (nickel-chromium-iron) alloy. Single or dual resistive elements may be used in the design, but the element must be must be of a single layer in cross-section. The element are normally an etched foil design with uniform in cross-section, and they have a minimum trace width of 0.010 in. (0.0254 cm) by design. Spacing between foil traces is tightly controlled and must not be less than 0.010 in. (0.0254 cm). The spacing between the outer foil trace and the heater edge (border trim) also cannot be less than 0.010 in. (0.0254 cm).

Lead Wires

Lead wires must be a minimum of 26 gauge when using high strength copper alloy conductors, and 24 gauge for all other copper conductors. Lead wire insulation must consist of polyimide (Kapton), polytetrafluoroethylene (PTFE/Teflon), or ethylene-tetrafluoroethylene (ETFE) materials.

Lead Termination

The termination of the lead wire has to be welded and contain a minimum of two weld points between the lead wire and landing bond pad. Lead wire terminations also need to be enclosed in a hardened Hysol epoxy potting, in order to secure lead wires to the heater so that lead pull stresses are not transmitted to the weld joint.

Power Rating

Polyimide thermofoil heaters used for space have a maximum power rating of 4.5 W/in2 (0.7 W/cm2) when suspended in still air at 25°C, although this specification is for test purposes only and is not indicative of the maximum power rating in application (with heater mounted to a heat sink). Actual rated power (or voltage) are specified in each application.

Visit this web page to view or download the entire NASA General Specification for Thermofoil Heater, All- Polyimide, Space Applications.

Kapton (Polyimide) Etched Foil Heating Elements

Kapton (Polyimide) Etched Foil Heating Element.

According to Wikipedia, "Polyimides have been in mass production since 1955. With their high heat-resistance, polyimides enjoy diverse applications in roles demanding rugged organic materials, e.g. high temperature fuel cells, displays, and various military roles. A classic polyimide is Kapton ..."

Kapton etched foil heating assemblies are constructed from a very thin etched foil circuit embedded between two layers of Kapton, or one layer of Kapton and some other material (such as alumina.) The result is a heater with features perfect for a wide variety of industries - from aerospace, to medical and scientific equipment, to research & development applications. 

Kapton heaters provide excellent heat transfer to adjoining surfaces with the release of minimal contaminants through the use of this very low mass, low outgassing, high dielectric material.  They provide very even heat distribution extremely fast heat-up and cool-down rates. Additionally, they can be constructed in just about any shape, size, wattage or voltage. They are also ideal for applications where distributed wattage (heating profile) is required. 

Furthermore, when the heater and ceramic insulator is bound in such a way to meet NASA’s low outgassing specification, Kapton heater assemblies are ideal for use in vacuum applications.

For more information, visit http://heater.belilove.com. Also, take a fast look at the video below.

BCE Flanged Gas Heater (Custom Electric Heating Element)

Here is an example of BCE's custom heating element design and manufacturing capabilities. This is their flanged gas heater.

Some of the design features are:

• Heat gasses to 400°C - 450°
• Body welded to pass 10⁻⁸ vacuum
• All 304 SST materials (other available).
• RoHS compliant parts and components.
• Embedded thermocouple probe.
• Can be used in gas chromatography and other applications.
• Wire length/type are customer specified.

For more information visit http://www.belilove.com or call (510) 274-1990.

Electric Heating Element Technical Reference Guide

Carnot engine diagram
(courtesy of Wikipedia)

Here’s a very handy reference document (courtesy of Hotwatt) for the application of electric heating elements in industrial and OEM applications such as extruding, vulcanizing, laminating, curing, bonding and thermoforming.

The heater application guide provides all the important technical look-up tables required to properly apply electric heaters, such as wattage calculation formulas and examples, properties of metals properties of non-metallic solids, properties of liquids and gases, suggested watt densities, estimates of wattage required, guide for heat losses, suggested sheath materials, installation,  Ohms Law, and typical wiring diagrams. The reference document is also very helpful when designing custom electric heating elements and designing a thermal system.

Electric Heating Element Technical Reference Guide from Belilove Company-Engineers

Electric Heaters for Heating Flowing Gases To 1000 F

Examples of air heaters
(click for larger view)

Do you need a small, compact electric heating system that can heat flowing gas or air up to 1000 degrees F.?

You may want to consider an inline "air process heater".

These fabricated (usually custom) electric heaters are self-contained, provide inlets and outlets, wiring,  sensors to measure internal temperatures, and are available in a variety of materials.

Air Process heater provide hot air and gas up to 1000^oF (540^oC) with infinite control by varying the voltage and air velocity supplied.

Units are fitted with a tubing “T” for convenient power lead outlet, while larger diameters can be supplied with post terminals on the sheath for direct electrical connections.

Designs can accommodate male or female NPT threaded fittings, hose adaptors, flanges, or custom fittings to your specifications.

Typical Air Heater Construction

Construction

1. Optional stainless steel bushing. 
2. Ceramic coil support.
3. Resistance element.
4. Stainless steel sheath. 
5. Silver solder.
6. Fiberglass insulated leads. 
7. Epoxy seal.
8. Copper tee.
9. Heliarc weld.
10. Optional brass bushing.

To properly size and select an air process heater:

• Determine the volume of air or gas(SCFM) you will be heating. 
• Determine temperature rise in degrees Fahrenheit(􏰁ToF).
• Calculate wattage required as follows:
• Watts = SCFM x delta-T ^oF / 3

Take into consideration the physical size requirements of your application and determine from the specifications chart for each size, the air heater best suited for your application.

Summary of Features:

• Exit air temperatures to 11000^oF (540^oC).
• Standard pressure rating is 80 psig at room temperature. 
• May be used with recirculating air up to 250^oF (121^oC).
• Designed for horizontal use.
• For use with clean, dry air.

Thick Film Heating Elements: An Excellent Choice for Custom OEM Thermal Designs

Custom Thick Film
Heaters and Circuits

Thick film heating elements, originally designed for the automotive and military industries, are manufactured by depositing several layers of conductor, resistors and dielectric on to an insulator via a screen printing process. The dielectric is normally some type of glass or ceramic and provides electrical insulation for the screen printed heating tracks.

Thick film heating elements are almost always custom designed for OEM applications. They can be designed in all shapes and sizes, and have an ability to provide very high watt densities with excellent controllability. The largest markets for these heating elements are appliances, analytical instruments, automotive, semi-conductor, medical device, scientific and military equipment.

Because of their inherent low mass, and their ability to carry high watt densities, thick film heaters are very efficient and are an excellent choice where a rapid heat-up (response) is required.

Advantages of thick film heaters are:

• Watt-Density up to 175 watts per sq. in. 
• Operating Temperature to 500 deg C
• Low Profile
• Excellent Control
• Very uniform heat profile
• Temperature sensors can be included on the heater
• Custom heating profiles
• Very rapid heater response
• Vibration and shock resistant
• Very customizable shapes, sizes and wattages