Wednesday, August 14, 2019

Mini Clean Flow - Stream Heater

Mini Clean Flow Heater
Mini Clean Flow Heater
A biotechnology company approached BCE in need of a custom heating solution. Their application required that the media must be heated to 75 °C in order to eliminate any pathogenic bacteria that may be present. Their current system was not heating the medium efficiently requiring a high watt density solution causing heater failure and carbonization of the material.

SCOPE

The Mini Clean Flow - Stream heater needed to satisfy the following:
  • Outlet of temperature of 75 °C (± 2 °C) to eliminate bacteria
  • Ability to place heater in a series flow configuration if necessary
  • Built in thermocouple for accurate temperature measurement
  • 185 Watt, 120 Volt
  • All wetted surfaces must be 304 Stainless Steel
  • Watt density below 30 WSI to avoid damage to the fluid or system
OUTCOME

Test Results
Test Results - Click for larger view.
BCE designed a double wall inline heater with exceptional heat uniformity and reduced heat losses. The Mini Clean Flow Stream heater was built with internal components designed to turbulate the medium to increase efficiency and minimize watt density. This compact, low mass heater had the ability to precisely control the inner temperature for either over-temp or process medium control. The Mini Clean Flow – Stream was the ultimate solution for this application resulting in a more efficient process to eliminate pathogenic material.

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

Monday, July 29, 2019

Electric Heating Elements: Cartridge Heaters

Cartridge Heater
Click for larger view.

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

Cartridge Heater
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.

Saturday, June 29, 2019

Mass Spectrometer Heaters

Mass spectrometry (or mass spectroscopy) is a technique of analyzing and identifying chemical substances by arranging gaseous ions in electromagnetic fields based upon their mass-to-charge ratios. A mass spectrometer is the instrument used in this analysis. Mass spectrometers operate according to a principle first discovered in 1898 by Wilhelm Wien, a German physicist, who determined that moving ions can be deflected by electromagnetic fields.


The mass spectrometers can be broken down into (5) basic components:
  1. The high vacuum system.
  2. The sampling system - the area is where the sample is conditioned and introduced.
  3. The ion source - the area is where the charged particle ion beam is produced.
  4. The analyzer - where the ion beam is separated into its components.
  5. The detector - where the ion beam separation data is collected.
Mass spec heater
A variety of heater used in mass spec.
Mass spectrometry is used for the identification of chemical elements to quantify their precise mass and concentration; for  analyzing organic and inorganic chemicals to detect small amounts of impurities;  analyzing complex organic material structure; determining chemical bond strength; and determining an unknown materials chemical and isotopic makeup.

Mass spectrometer heating elements, referred to as source heaters or gas line heaters, are used in mass spectrometers are used to turn the sample (typically in an aqueous or organic solution) into a vapor for analysis. The heaters are part of the sample conditioning system, prior to the analyzer and detector areas, where the vaporized sample is then bombarded by ionized high-energy electrons and analyzed.

Mass spec heater
An alternative design heater.
Heaters used in mass spectrometers are compact in design and provide a fairly high power density. They are fast responding and operate at temperatures up to 400 deg. C. They include internal temperature sensors for accurate control and limiting. While mass spec vary in form and fit, they all provide the same basic function -  as the energy source for the vaporization of the sample containing the atoms or molecules of interest.

BCE (Belilove Company-Engineers) is a leading manufacturer of electric heating elements for mass spectrometers. With decades of experience in custom engineering and design of heating elements for analytical instrumentation, they are an excellent candidate to discuss the unique needs of your application.
Mass spec heater
Yet another style mass spec heater.

BCE
510-274-1990

Tuesday, June 18, 2019

The Operating Principle of Thermocouples

When two dissimilar metal wires are joined together at one end, a voltage is produced at the other end that is approximately proportional to temperature. That is to say, the junction of two different metals behaves like a temperature-sensitive battery. This form of electrical temperature sensor is called a thermocouple:



This phenomenon provides us with a simple way to electrically infer temperature: simply measure the voltage produced by the junction, and you can tell the temperature of that junction. And it would be that simple, if it were not for an unavoidable consequence of electric circuits: when we connect any kind of electrical instrument to the thermocouple wires, we inevitably produce another junction of dissimilar metals. The following schematic shows this fact, where the iron-copper junction J1 is necessarily complemented by a second iron-copper junction J2 of opposing polarity:


Junction J1 is a junction of iron and copper – two dissimilar metals – which will generate a voltage related to temperature. Note that junction J2, which is necessary for the simple fact that we must somehow connect our copper-wired voltmeter to the iron wire, is also a dissimilar-metal junction which will also generate a voltage related to temperature. Further note how the polarity of junction J2 stands opposed to the polarity of junction J1 (iron = positive ; copper = negative). A third junction (J3) also exists between wires, but it is of no consequence because it is a junction of two identical metals which does not generate a temperature-dependent voltage at all.

The presence of this second voltage-generating junction (J2) helps explain why the voltmeter registers 0 volts when the entire system is at room temperature: any voltage generated by the iron-copper junctions will be equal in magnitude and opposite in polarity, resulting in a net (series-total) voltage of zero. Only when the two junctions J1 and J2 are at different temperatures will the voltmeter register any voltage at all.

For more information about thermocouples (or any temperature sensor), contact BCE. They can be reached by calling 510-274-1990 or by visiting their web site at https://bcemfg.com.

Reprinted from "Lessons In Industrial Instrumentation" by Tony R. Kuphaldt – under the terms and conditions of the Creative Commons Attribution 4.0 International Public License.

Friday, May 31, 2019

BCE Smart Flow: for OEMs Who Need Very Precise, Uniform Heat

The SMART FLOW liquid heater is designed for applications where fast heating of liquids is required. All parts exposed to liquid flow are constructed of 304/316SS (other materials available). All units have built-in Type J or K TC with potential of added adapter for outlet flow.

The Smart Flow is often customized to suit the exact power, electrical, and mechanical requirements of the application. BCE engineers are ready to provide application assistance to design and apply the perfect Smart Flow for your needs.

Smart Flow Heaters Applications Examples:

9 KW STEAM GENERATOR

BCE Smart Flow
9.0 KW (2 Zone 4500W each) (+/-10%), 240V, 23.5" Internal Length


7.5 KW STEAM GENERATOR


BCE Smart Flow
7.5 KW (2 Zone 3750W each) (+/-10%), 240V, 31.5" Internal Length


1.75 KW LUBE OIL HEATER


BCE Smart Flow
HEATER: 1750W(+/-10%), 120V, 22-23WSI, 31.5" Internal Length
SMART FLOW HEATER
  • Wetted parts constructed of 316 stainless steel standardly. Other materials available as options.
  • Liquid flow passes over an enclosed heated body, does not contact the heating element directly.
  • Multiple threaded fittings available: NPT, SAE, BSP & VCR
  • Heater designed to provide very uniform heating.
  • Made in U.S.A.
For more information about custom electric heating elements, contact BCE by calling (510) 274-1990or by visiting https://bcemfg.com.

Tuesday, May 28, 2019

Custom Coiled Cable Immersion Heater with Thermocouple and Thermal Cutout

Custom Coiled Immersion Heater
BCE Custom Coiled Immersion Heater
with thermocouple and thermal cutout.
A major US Aerospace company approached BCE in need of a custom heating solution.  

Their existing heating element failed to evenly distribute heat inside a water reservoir, leading to thermal stratification and hotspots. 

Additionally, while the customer's existing thermal system included temperature limiting devices, the new heater design required it's own thermal cut-out to ensure over-temperature protection and remove any possibility of a runaway condition.

The coiled immersion heater needed to satisfy the following:
  • Temperature uniformity throughout the heated section (± 3 C)
  • Hermetic seal 
  • Over-temperature heater failure
  • Thermocouple for additional temperature measurement
  • 275 Watt, 115 Volt
OUTCOME

Click for larger view.
BCE designed a highly effective coiled heater with exceptional heat uniformity.  An additional
thermocouple was welded to the sheath of the heater to ensure accurate temperature measurement. A thermal cutout was placed into the NPT bushing and potted with thermally conductive epoxy to allow for heater failure if all other safety systems fail. 

BCE was able to design, create 3D models/ drawings, and provide the custom heating elements within a 3 week timeframe.

Contact BCE:
510-274-1990