Monday, March 25, 2019

Level Measurement White Paper

This paper, courtesy of Yokogawa Corporation of America, covers level measurement using differential pressure (DP) level transmitters. A DP level transmitter uses the head pressure and specific gravity of the media to infer the level in the vessel. It is a widely-used level technology having the advantage of being based on a well-understood principle. It is an excellent selection for clean liquids but also works well with viscous liquids and slurry/sludge; but, is not recommended for solids. The disadvantage is the limited temperature operating envelope of the transmitter. Adding a remote diaphragm seal system to the DP transmitter overcomes this limitation.

Wednesday, March 13, 2019

Repeatable and Reliable Level Measurement for Granular Activated Carbon in Corn Syrup Production

Granular Activated Carbon in Corn Syrup Production
Granular activated carbons (GAC) are prepared from a variety of local raw materials of vegetable origin such as wood and peat, or of mineral origin, such as coal.

The presence of suspended particles in the production of corn syrups impacts the efficiency of steps in the refining process. These suspended particles are removed during clarification using granular activated carbon (GAC). GAC is used for both decolorization and to filter impurities such as amino acids and polysaccharides.

A corn syrup producer was looking for a reliable, low maintenance level transmitter to measure GAC in a carbon column.

It is important to measure the granular activated carbon level because, after the GAC filters out the impurities, the spent GAC is then mixed and cleaned with water forming a slurry, which is pumped into carbon columns.  The level of the granular activated carbon slurry in the column must be accurately measured so it can be separated from the water and conveyed back to the reactivation furnace. The level inside the column is critical to the efficiency of the re-carbonizing process.

Other technologies, including the electromechanical  displacer level systems, had been tried without success. The client wanted a reliable, low maintenance solution.

SOLUTION

The Hawk ORCA Sonar low frequency interface transmitter, with automatic sludge cleaning, was installed and tested.  The ORCA's low frequency sonar was able to measure the GAC interface very accurately through the dirty, sticky and viscous black water. The ORCA system provided high reliability and excellent repeatability, which improved automation control and reduced maintenance downtime.

The ORCA Sonar Bed Level transducer emits a high powered acoustic pulse, which is reflected from the interface density selected. The reflected signal is processed using specially developed software algorithms, that eliminate lighter floating densities and stratified layers, allowing measurement of RAS or BED levels. It can be calibrated to measure lighter densities like FLOC or one of the outputs could be used for a CLARITY output, similar to a basic turbidity transmitter measuring solids in suspension. By choosing the correct sonar transducer frequency, the ORCA sonar guarantees the optimized performance when measuring both light and heavy density interfaces.

For more information, contact Power Specialties, Inc. Call them at (816) 353-6550 or visit their web site at https://powerspecialties.com.