Tuesday, March 31, 2015

Rugged In-Line Viscometer for Real-Time, On Location Use

The AMETEK Chandler Engineering Model 3330 In-Line Viscometer provides real-time on location measurement of fracturing fluids viscosity. It is a rugged instrument designed and manufactured to withstand the rigors encountered within field operations. Using Couette Bob and Rotor geometry, the Model 3330 is a concentric cylinder viscometer that meets all API requirements for viscosity measurements of stimulation fluids used in well servicing.

The Model 3330 is extremely durable and designed to withstand the harsh field conditions encountered by Frac Crews every day. Full real-time viscosity monitoring during pumping operations may now be achieved.

The Model 3330 is a ruggedized version of the 3500 series bench-top viscometer and comes standard with API R1-B1 geometry. This instrument is manufactured to endure the harsh environments in which it is designed to operate. Operating at a fixed shear rate of 511 sec-1, the Model 3330 sends a continuous measurement of viscosity and temperature to a Control Treatment Monitoring Vehicle via 4-20 mA signal loops. The instrument also provides a direct readout of the current viscosity within the front panel display. This state of the art instrument is also available with an optional pH probe for monitoring the pH of the fluid. For more product information, a Chandler Engineering Model 3330 cut sheet can be downloaded here.

Friday, March 27, 2015

Control of Fermentation Processes

(reprinted with the permission of AMETEK Process Instruments)

Fermentation Process
Process Overview 

Fermentation is the process by which living organisms are cultured or grown to produce a specific product. The products can be as simple as baker’s yeast and alcohols, or as complex as therapeutic proteins, antibiotics, enzymes, and genetically engineered materials. Regardless of the end product, fermentation reactions must be carefully monitored to gauge the health of the culture, and to determine when the culture can be harvested. Since these are living organisms, the levels of oxygen and carbon dioxide in the off-gases can be used to follow the progress of fermentation. The ratio of carbon dioxide to oxygen is called the respiratory quotient (RQ) and is the prime indicator of culture health. While these measurements can be made by several techniques, the most accurate RQ determination requires complete knowledge of the flow of gases into and out of the reactor. By virtue of its ability to measure all of the gases entering and exiting the reactor, the ProLine process mass spectrometer provides a highly refined control signal to maximize culture health and productivity.

Traditional Approach

Dissolved O2 and CO2 Probes

Fermentation reactors are typically equipped with insitu probes to measure dissolved O2 and dissolved CO2 in the broth. Both of these techniques are non-interactive, so that if one of the probes fails or falls out of calibration, the other probe does not reflect the failure. This would show as a shift in the balance of the respiratory quotient and might cause detrimental changes to he process. Both types of dissolved probe typically have relatively long sampling times (on the order of minutes) and they also exhibit poor recovery response when dosed with higher levels of O2 or CO2.

Tuesday, March 24, 2015

Cartridge Heaters

Belilove Cartridge Heater
Styles of Cartridge Heaters
A cartridge heater is a cylindrical electric heating element constructed by tightly winding nichrome wire around a ceramic bobbin, and inserting the wound bobbin into a metallic tube (sheath). The tube is then backfilled with magnesium oxide (MgO) powder to electrically insulate the nichrome wire from the sheath. The heater diameter is then reduced (swaged) to compact the magnesium oxide for better dielectric, while at the same time improving thermal conductivity.

Cartridge heaters come in many diameters and lengths. They vary in voltages, wattages and watt densities. Sheath materials are typically Stainless Steel of Incoloy 800. The electrical leads terminate from one end of the heater and vary in length and insulation material, depending on application and operating temperatures.

Most cartridge heaters are used in some form of die or platen heating. A close tolerance hole is drilled into a metal block, and the proper diameter heater is then inserted in to the hole. It is best to make sure the diameter of the heater is just a few thousands of an inch less than that of the hole, so that maximum surface contact, thus thermal conductivity, can be achieved. A loose fit will cause the internal temperatures of the cartridge heater to climb and the heater will fail prematurely.

Common die heating, or platen heating, applications are:
  • Injection mold platen heating
  • Heating medical equipment components
  • Compressor sump heating
  • Bolt heating
  • Extruders
  • Packaging equipment
  • Sealing equipment
  • Analytical equipment
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