Tuesday, July 29, 2014

High Purity Fluid Electric Heaters

custom electric gas heater
Transfer Line
Heater Assembly
In many biomedical, pharmaceutical, semiconductor, electronics or R&D laboratory applications, special purpose electric heaters are required for heating high purity fluids. These heaters typically must be ruggedly designed, made from materials immune to process contamination and be vacuum tight. They can be subject to high temperatures, harsh solvents, and corrosive gases. Many times they must maintain a seal for full vacuum, demonstrate a unique or even heating profile and be able to be closely controlled.

The misapplication of screw plug immersion heaters, screwed into a stainless steel welded vessel, offer more problems than solutions due to leaks, material compatibility, poor controllability, and bulky size.

custom electric fluid heater
Transfer line
heater assembly
The answer is in a custom high purity fluid heater designed with the process in mind.

Custom electric heating elements are available designed to handle high vacuum, high temperatures, utilize glass liners for ultra-pure gases, offer 316 stainless steel parts, provide internal RTDs for control and can be temperature profiled.

General Specs for these types of custom fluid heaters are:

  • Variety of voltages.
  • Wide range of watt densities.
  • Temperatures up to 350°C.
  • Heater length can be profiled to generate a liner temperature profile.
  • Vacuum compatible up to 1.0 x 10-8  STD. CC/SEC Helium.
  • Can be provided with internal sensors (RTD or thermocouples).
  • Can be glass lined for ultra pure gas application.

Careful review of the application is important and the help of an experienced application engineer is required, but the outcome of the test, process or product will be infinitely improved.

Friday, July 25, 2014

Intro to Direct Liquid Injection (DLI) Vaporizer

DLI vaporizer
Direct Liquid Injection Vaporizer
Conventional vaporizing technologies have many limitations. Vapor draw systems or bubblers are difficult to start and stop, require very close control of temperature and pressure, and are inefficient at generating well controlled vapor mass flow. Flash vaporizers applying heat via hot metal surface, which cause problems with thermal breakdown of liquid precursors. It also can cause liquid buildup on the treatment surface, causing problems in deposition.

It's also very challenging to precisely measure the amount of vapor mass that is actually being delivered from a conventional vaporizer. In applications where precise vapor mass addition is required, a measurement/control device such as vapor mass flow controllers must be used. This significantly increases the cost and complexity of the vapor system.

Tuesday, July 22, 2014

Have You Considered a Cast-in Heated Part?

Cast-in semiconductor chuck heater
When OEMs (original equipment manufacturer's) look for the best way of adding heat to their equipment, they're faced with the same choices - clamping, bonding or inserting. But there's another, more efficient and productive way to go - cast-in aluminum or bronze heaters.

Friday, July 11, 2014

Custom-Fabricated, Mass Flow Controller (MFC) Flow Validation Cart Allows for Easy Servicing, Reduced Downtime, and Reduced Inventory

The process of calibrating, servicing and troubleshooting mass flow controllers is a time consuming and expensive endeavor. The typical scenario requires stopping the process and removing the MFC for accuracy checks. The downtime and labor required is very costly, and the advantages for in-situ (without removing it from the process) flow accuracy checks and troubleshooting is quite clear.

An innovative approach for in-place accuracy checks has been developed by Belilove Company. Their solution is a mobile station that includes multiple thermal mass flow meters connected via RS-485, power supplies, software and all the necessary plumbing.

Tuesday, July 1, 2014

Flow, Pressure, Pneumatics, and Process Control Basics Tutorials Videos

If you're interested in the principles of pressure control, flow control, pneumatics, hydraulics and other process control subjects, the Columbia Gorge Community College offers a wonderful selection of videos. They are presented by a teacher named Jim Pytel who does a very nice job. We'll repost one on flow control valve basics here and suggest you recommend them to any new engineering student, tech, or service rep you know.