Monday, November 20, 2017

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

Multi-Thermocouples and Heater Feedthrough
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 

Thursday, October 19, 2017

BCE’s Foil and Cartridge Heaters: Braving Extreme Weather Conditions in Rain Gauges

Rain Gauge Heater Combination
Rain Gauge Heater Combination
Rain gauges are essential in collecting data on precipitation an area receives over a period of time. This information is used by scientists to track biodiversity and develop advanced meteorological instruments aiding notably in aviation.

However, rain gauge performance can be severely impaired in regions where extreme cold weather dominates. In fact, a leading manufacturer of aviation technology solutions approached BCE to develop a means to heat their tipping bucket rain gauges in regions impacted by heavy snowfall and freezing rain. 

In order, for these rain gauges to remain operational, precipitation needed to be melted in the collection funnel, then remain fluid inside the gauge and finally drain with ease after the data had been collected without freezing with exposure to the outside air.

SCOPE


Electric heaters to be incorporated in the rain gauge needed to meet the following specifications:
  • All heaters needed to operate at 220V 
  • Heater used for collection funnel needed to operate at 160W 
  • Heater used for inside of gauge needed to operate at 130W 
  • 2 drain tubes required heaters to not exceed operation at 25W each 
  • Operating temperatures between -30°C to 45°C 
  • Temperature control required for heaters used in collection funnel and inside the gauge 
  • Temperature to remain approximately 15°C inside collection funnel 
  • Temperature to remain approximately 5°C inside gauge 
  • Heater used for collection funnel was not to exceed 8” in height and width 
  • Heater used for inside of gauge was not to exceed 11” in height and width 
  • Heaters used inside drain tubes needed to operate continuously and not exceed 20” in length 
OUTCOME

BCE proposed foil heaters to heat the collection funnel and the inside of the gauge. These heaters were precisely manufactured to achieve the perfect form and fit needed for the rain gauge components. Not only did they match the exact electrical specifications, the resistance element laminated between aluminum foil shells provided optimal surface heating. Furthermore, each of the foil heaters were also embedded with thermostats for accurate temperature control. For the drain tubes, BCE manufactured cartridge heaters to the desired length and with a robust stainless steel sheath providing continuous operation. These cartridge heaters further ensured maximum heat transfer through the close proximity of the element wire and sheath. This also allowed minimal internal temperatures in the cartridge heaters increasing heater life and preserving excellent dielectric strength, two essential criteria for this application. BCE’s contribution proved to be a huge success in the design and operability of these tipping bucket rain gauges.

Contact BCE for any electric heating design or application. You'll be pleased with BCE's experience, knowledge, and service. Visit them at http://belilove.com or call (510) 274-1990. Download the PDF Application Note here.

Thursday, October 12, 2017

Simply-designed, Versatile and Robust Vacuum Feedthrough

plug feedthrough
BCE’s plug feedthrough is an ideal product for any vacuum application. Not only is it easy to install and withdraw due to its stainless steel, threaded plug body, it can be embedded with leads, thermocouples and RTDs. Thus, it can be designed and customized to meet all requirements at a low production cost.

As it is sealed with BCE’s proprietary epoxy meeting NASA ASTM E595, outgassing is excessively low. Furthermore, all leads come with standard KAPTON insulation to limit contamination in vacuum applications. It should be noted that the 316 SS construction allows it greater resistance to corrosion increasing product life. This means fewer replacements.

Specifications
  • CAD modeling and engineering design consultation. 
  • Vacuum compatible to 10-9 ATM.CC/Sec. 
  • Max. operating temperature: 200°C. 
  • BCE proprietary epoxy meets NASA ASTM E595 low outgassing spec. 
  • Corrosion resistant. 
  • Embedded thermocouple(s), lead wire(s) and rtd(s) with kapton insulation (multiple options available). 
  • All dimensions, materials and features can be customized.

Friday, October 6, 2017

BCE’s Vacuum Ring Heater: Defying Boundaries in Degassing Chambers

BCE Vacuum Ring Heater
BCE Vacuum Ring Heater

Providing uniform heat to semiconductor devices in degassing chambers is essential in extracting impurities. This can only be achieved if a heating device has the proper fit and temperature uniformity for a given chamber. It is for this very application that BCE was approached by a large semiconductor company from Silicon Valley. In order to heat this company’s semiconductor wafers, it was critical that the heating device be manufactured to fit precisely into a large and circular degassing chamber posing manufacturing challenges due to dimensional and application parameters. BCE was able to provide extensive design consultations, 3D CAD modeling and lean manufacturing capabilities to this semiconductor giant at a competitive price. All these services were rendered while catering to all requirements needed to successfully manufacture their products.

SCOPE


The heating apparatus needed to satisfy the following criteria:
  • Vacuum compatibility to 10-8 Torr 
  • Maximum Operating Temperature: 200°C 
  • Temperature uniformity of ±4% at 150°C 
  • Operate at 1500W, 240V 
  • All epoxies used needed to meet NASA’s Low Outgassing Spec (ASTM E595) 
  • Reduced contamination from components inside chamber 
  • Temperature sensing capability 
  • Circular configuration between 34 and 36 inches in diameter 
  • Height of part was not to exceed 1 ft. 
  • Effective heat transfer from heating device with reduced machining cost 
OUTCOME

BCE’s Vacuum Ring Heater proved to be the ideal product for this application. Its strong aluminum ring construction ensured effective heat transfer to the circular wafers while keeping manufacturing costs low. Furthermore, its strategically embedded heater with stainless steel sheath allowed the device’s temperature uniformity to remain at ±2% at 150°C, greatly exceeding customer requirements. Moreover, BCE’s proprietary epoxy meeting NASA’s low outgassing spec was used as the primary sealant and KAPTON insulated leads were provided for the heater and integrated thermocouple to reduce contamination. In fact, the integrated thermocouple type K further served to monitor the temperature supplied to the chamber. Finally, all electrical, vacuum and dimensional requirements were met to provide the most optimal thermal environment.

Visit this link for more information on the Vacuum Ring Heater, or call (510) 274-1990.

Monday, October 2, 2017

Vacuum Thermowell and Heater Assembly Simultaneously Heats and Monitors Semiconductor Wafer's Temperature

BTU requirement and temperature control are critical in the fabrication of silicon wafers in the semiconductor industry. Seldom can a product provide both a thermally effective means to heat wafers and simultaneously monitor their respective temperature. BCE’s Vacuum Thermowell and Heater Assembly achieves both of these criteria. Its aluminum thermowell houses a cartridge heater capable of supplying uniform heat, which can be monitored through an embedded thermocouple.

Furthermore, a flange at the end of the thermowell allows for easy installation into any vacuum port and provides an effective seal via its dovetail O-ring groove. An aluminum construction further ensures that the entire assembly remains lightweight and inexpensive to machine, reducing overall product cost. Moreover, multiple RTDs are hermetically sealed into the thermowell to allow for precise temperature monitoring of wafers and other components while maintaining vacuum integrity. They can be positioned and designed for any application, as can the thermowell. In order to prevent any outgassing and minimize release of contaminants into the chamber, the RTDs are sealed using BCE’s proprietary epoxy meeting NASA’s low outgassing spec and are available with Kapton leads.

Check out the BCE Vacuum Thermowell & Heater Assembly web page for more detail.

Sunday, October 1, 2017

SuperCirc Heater: Revolutionizing Thermal Efficiency in the Petrochemical Industry

SuperCirc Heater
One of the most effective ways to increase heating of plant utilities is by pre-heating combustion gases supplied to burners. This can be challenging especially when a small footprint, high thermal efficiency and low maintenance are required in very harsh environments. In fact, BCE was approached by an international petrochemical giant seeking to replace their line of cartridge heaters used for this very application. This multi-billion dollar oil and gas company was primarily concerned with improving thermal efficiency and heater life as heaters needed to be replaced often due to exposure to corrosive materials and high watt densities. Replacing these heaters was proving to be quite costly and a quick remedy was needed to allow for greater profit generation.

SCOPE
  • The heater needed to meet the following requirements: 
  • Thermal efficiency needed to be tripled by reducing watt density 
  • 200W, 120V 
  • Heater sheath material capable of withstanding a corrosive environment 
  • Gas needed to be pre-heated to a temperature of 300°C 
  • 10 minute ramp time 
  • Gas flow needed not be exposed to any resistive material 
  • Built-in thermocouple for accurate temperature monitoring 
  • Easy installation into existing BSP threaded ports 
  • Heater body dimensions to not exceed 10” x 1” x 1” envelope due to space restriction 
OUTCOME

BCE proposed its SuperCirc heater as the most viable option for this dilemma. Its revolutionary fin design tripled thermal efficiency by tripling the heated surface area within the prescribed electrical and dimensional specifications. In effect, this resulted in decreasing the watt density from 36 W/in2 to 14 W/in2; greatly diminishing surface temperatures on the heater increasing heater life. Furthermore, not only was it able to ramp to 300°C in under 10 minutes exceeding customer expectations, its robust 316 stainless steel construction proved to be optimal in preventing heater degradation with exposure to harsh chemicals. Furthermore, an embedded, grounded, type K thermocouple provided accurate temperature monitoring, and the heater body inlet and outlet fit effortlessly into the existing BSP ports on customer site.

For more information, visit http://heater.beleilove.com or call 510-274-1990.

Tuesday, September 12, 2017

Example of a Large Vacuum Chamber Used at NASA

Facility 238 is a large, vertical, cylindrical thermal vacuum chamber which is used for thermal vacuum and thermal balance testing, and baking out spacecraft hardware. Test articles are normally loaded through the top of the chamber using the building crane; however, small payloads can be transported through the personnel entrance. Ports for electrical feedthroughs, liquid/gas feedthroughs, and viewing are located around the perimeter of the chamber. A clean tent at the chamber entrance provides class 10,000 cleanliness conditions.

Mode of Operation


With the chamber dome rolled back, the overhead crane is used to lower the payload onto the support fixture. In most cases, special fixturing must be designed due to the uniqueness of the test article support system. Once installed, the payload is instrumented and connected to the ground support equipment via feedthroughs. Access to the chamber is throught a clean tent. The use of cleanroom procedures and the wearing of clean garments are required when working in the chamber.

Initial chamber evacuation is provided by two rotary piston mechanical pumps, with four closed cycle cryopumps for high vacuum pumping. Each cryopump is isolated from the chamber by a sliding gate main valve to allow off-line cool down and regeneration.

Parameters

  • Test Pressure: 5 x 10-7 mmHg
  • Shroud Temperature: GN2 mode -90°C to +90°C , LN2 mode -190°C
  • Chamber Pump: 4 cryopumps
Physical Characteristics
  • Test Volume: 12' x 15'
  • Payload Support: Floor level - 4' square platform
  • Side Wall: Hardpoints at 6' and 12' levels
  • Crane Capacity: 5 tons Viewports: 9" diameter
  • Standard Electrical Feedthroughs: 36 - 37 pin connectors (RF feedthroughs available on request)
Integral Instrumentation
  • Pressure: Capacitance manometer - Atm to 10-3 mmHg
  • Ion Gauge: 10-3 mmHg to ultimate
  • Payload Temperature: 324 channels of thermocouple or thermistor channels
  • Contamination Monitor: TQCM, coldfinger, residual gas analyzer