Tuesday, September 22, 2020

BCE Vacuum Feedthroughs Allow you to "Take It All Through the Wall"

Vacuum Feedthrough

The development capabilities for vacuum systems and components are continually refined by advances in analytical methods, medical science, and semiconductor manufacturing. The need for process monitoring and control is growing, and it is becoming increasingly difficult to get the necessary power and control signals into vacuum chambers. In order to pass electrical signals, light beams, or pure gases inside a vacuum chamber, devices referred to as vacuum feedthroughs are used. 

Leakage into or through the vacuum feedthrough can not be tolerated as the vacuum seal is essential to preventing leakage and ensuring process integrity. Glass-to-metal and ceramic-to-metal seals, historically the favored technology, are increasingly troublesome - not because of their performance, but because they are limited by size, design, durability, and electro-magnetic shielding choices. Due to this fact, engineers worked with what was available because no suitable alternatives existed. 

Fortunately, new, advanced sealing epoxy compounds were developed that provided exciting opportunities for vacuum feedthrough manufacturers. These new materials opened the door for a more efficient and flexible feedthrough design.

Today's epoxy vacuum feedthroughs have nearly the same application reach as their glass and ceramic cousins in low to medium temperatures. Epoxy vacuum feedthroughs provide an outstanding alternative in terms of customization and versatility for designers and engineers. Shapes, angles, and curves are not a concern. It is possible to use virtually any form of shielded wire or cable. Production in minimal amounts for prototyping and R&D, custom epoxy vacuum feedthroughs can be easily supplied. Modern epoxy feedthroughs sustain a vacuum of up to 10-8 Torr, with continuous temperatures of up to 200 ° C (intermittent 300 ° C), and therefore meet the outgassing criterion of NASA of < 1.0 percent Total Mass Loss (TML). Liquid epoxy's ability to flow and fill spaces thoroughly provides an important additional benefit. In most applications, epoxy feedthrough may be used where a glass-to-metal or ceramic feedthrough is used-the; only notable exceptions are in extremely high-temperature applications or where organic compounds are not authorized. 

Within the restricted world of glass-to-metal and ceramic-to-metal feedthroughs, designers and engineers no longer have to wonder. Epoxy feedthroughs are a modern, exciting player in the game, making them a very enticing option with lower cost, fast prototyping, and more versatile design capability.

For more information about vacuum feedthroughs, contact BCE. Call them at 510-274-1990 or visit their website at https://bcemfg.com.

Friday, September 4, 2020

Sunday, August 30, 2020

BCE Cartridge Heaters


BCE Cartridge Heaters

BCE manufactures a wide range of cartridge heaters for a variety of industrial applications, and can provide you with heaters manufactured to your exact specifications. Cartridge heater size, sheath, leads, terminals, wattage and voltage can all be adapted to meet your exact needs.

Low to Medium Watt Density Cartridge Heaters

BCE precision cartridge heaters provided localized heat to restricted work areas requiring close thermal control. Dies, platens, and a variety of other types of processing equipment are efficiently heated and can be closely controlled. Part work temperatures of up to 1250ºF are obtained by a combination of heater location and proper wattage output. Basic heater designs are readily adaptable to a wide variety of special requirements, sizes, or ratings. Heating element wires are constructed just beneath outside surface for optimum heat transfer and minimum core temperature, resulting in faster part heating.

The maximum power densities for low to medium watt density cartridge heaters is computed at 60 watts per square inch of heated surface. With proper fit in a heat sink, long life can be expected. Consult BCE for higher watt density applications. Lower watt density will result in longer life. Standard voltages are either 120V or 240V. Other voltages are available.

High Watt Density Cartridge Heaters

The useful life of a Cartridge heating element is determined by how quickly the heat generated in the internal resistance wire can be dissipated to the outside sheath. BCE high watt density cartridge heaters are design and constructed in a way that accelerates the transfer of heat from the resistance wire to the sheath. This is accomplished by relocating the wire so that it is closer to the sheath; and swaging the outside diameter of the heater, thereby compressing the magnesium oxide filler so that it becomes an improved conductor of heat from the wire while maintaining its dielectric properties. By improving the heat transfer rate, it is possible to manufacture elements of higher densities because the differential between the wire temperature and the sheath temperature has been minimized.

Common applications for high watt density cartridge heaters are dies, heat sealing machines, hot melt adhesive equipment, plastic molding machines, platens, and shoe machinery.

Optimizing Performance and Operating Life of High Watt Density Cartridge Heaters

Cartridge Heater Fit

High watt density heaters require careful fit to insure optimum performance and long life.  BCE recommends that installation holes not be drilled and reamed over .002” or larger than the nominal hole size required. 

Cartridge Heater Cycling

Rapid cycling of heaters from very low to very high temperatures shortens their life considerably. It is recommended therefore, that care be taken to compute the correct wattage for any given installation. Optimum wattage should result in a 50/50 off/on cycle.

Location of temperature Sensor and Cartridge Heater

When thermostats are used, the sensing element ought not to be placed further than 1⁄2" away from the heater wherever possible.

For more information about cartridge heaters, call BCE at 510-274-1990 or visit their website at https://bcemfg.com.

Monday, August 17, 2020

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.


Sunday, July 26, 2020

Types of Vacuum Feedthroughs

Vacuum Feedthrough

The main purpose of a vacuum feedthrough is to allow a substance, or a form of energy, to pass from outside of a sealed vacuum chamber to the inside. In so doing, the feedthrough must remain leak-free under both high and ultra-high vacuum conditions.

While quite different in construction style and application, the terms vacuum feedthrough, hermetic feedthrough, and electrical feedthrough are often used interchangeably by engineers, researchers, and scientists. No matter what they are called, they have the common purpose of allowing electricity, light, gas, or liquid to pass though a vacuum chamber's walls. The following are descriptions of several of the most common kinds of vacuum feedthrough:

A fiber optic feedthrough transfers emitted light through a fiber optic cable into  vacuum apparatus They provide a simple way to use optical fibers with vacuum chambers. They are available with flanged or screwed connections.

An electrical feedthrough carries some form of electrical energy into vacuum apparatus. The feedthrough usually has a single set. or multiple sets, of electrical conductors. These conductors can be pins, standard types of connectors, or lead wires.

Liquid and gas feedthroughs are used to carry liquids of gases in and out of a vacuum apparatus. The transfer is normally done using stainless steel tubes with epoxy-to-metal, ceramic-to-metal, or via an embedded compressing fitting.

A thermocouple feedthrough is  used for temperature measurement in vacuum applications. These feedthrough carry temperature instrumentation signals into  vacuum apparatus while providing electrical isolation and a hermetic seal. They are leak free in vacuum environments and can be supplied in most thermocouple calibrations, such as Type J, K, T, E, R, S, etc.

BCE, a Northern California based manufacturer of precision vacuum feedthroughs has a convenient vacuum feedthrough configuration tool here.

For more information on vacuum feedthroughs, contact BCE. Phone them at 510-274-1990 of visit their site at https://bcemfg.com/feedthroughs.

Monday, June 22, 2020

New Vacuum Feedthrough Product Designer from BCE

Vacuum Feedthrough Product Designer

BCE, a California based manufacturer of high quality electric heating components and vacuum feedthroughs, is now offering a vacuum feedthrough product designing app on their website, bcemfg.com.

The app allows the visitor to select from an array of options and design their own vacuum feedthrough. Once the design is complete, the visitor can request pricing and delivery from BCE automatically though an integrated email messaging system. The visitor also receives a confirmation of their request.

The vacuum feedthrough designer is the third in a series of online BCE product configuration tools. The three currently available are for cartridge heaters, BCE's Mini Clean Flow air and gas heaters, and now for vacuum feedthroughs.

You can check them out here - https://bcemfg.com/article_277_Product-Designer.cfm

BCE designs and manufactures custom electric heating thermal systems, electrical feedthroughs, pneumatic feedthroughs, and fiber optic feedthroughs. You can learn more about BCE at https://bcemfg.com, or if you have an immediate need, call them at 510-274-1990.