|
 MARIETTA, GA – 07/2010
-
A company in the Northwest US makes a
variety of soups that are sold to restaurants and commercial
institutions. The soups are made in 960 gallon kettles and cooked as
ingredients are added. Material agitation is performed at various times
throughout the cooking process in order to ensure that all of the
ingredients are mixed properly and that there is a consistent amount of
ingredients throughout the kettle. This ensures that when the soup is
packaged, the various containers will have the same amount of solid
and liquid ingredients. Once the soup is properly cooked, it is pumped
to a package machine and conveyed to inventory.
Challenge
The plant manager was looking for a better way to monitor the level in the soup kettles. The soup making
process involves monitoring and controlling the speed of two different material agitators in the kettle. As
ingredients are added, the speed of the agitators is increased or decreased depending on the level reading.
The level reading is important because it is used to control the agitators which in turn ensure that the
ingredients are mixed properly to ensure consistent product quality throughout the entire batch.
Before the Siemens representative recommended a better option, the company had been making (and
guessing) the level measurements manually. Production employees would lift the lid and expose themselves
to potential injury and possible contamination of the product. The customer had used load cells in the past,
but had problems with water ingress into the cells. They also didn’t want to lift the kettle in order to install the
load cells because this would interfere with production schedules.
Solution
The local Siemens representative provided the customer with a site survey of their process, and counseled
the customer on the different level technologies available with the advantages/ disadvantages inherent in
each for this application. Once it became clear that a non-contacting level solution was the best overall choice
for this customer, the representative suggested they try the Siemens LR250 Radar level transmitter, and
performed a “live” test with the instrument to prove that this technology would solve the customer’s problem.
 The LR250 radar level transmitter is mounted on top of each kettle to monitor the
material level of the soup as it is being cooked. It is connected to the kettle with a
custom removable flange/coupling. The instrument sends a 4-20 mA signal based on
inches of level to a PLC which in turn controls the agitator speed to ensure proper
mixing. The 4-20 mA signal is scaled in the PLC so that inches of product are converted
to gallons of product in the kettle.
The customer is now getting improved quality and consistency in their product without
manual intervention by employees opening the kettle lids and risking injury and/or
contamination. There is no longer a problem of some employees “guessing” differently
than others as to the product level
Benefits
-
Ease of use: Plug and Play setup, easy mounting in nozzles, and very few restrictions due to
location, obstructions, and nozzle interference.
-
Superior design and performance: echo
profiles for diagnostic support, short blanking distance for an
improved minimum measuring range; improved measurement,
reliability and Auto False-Echo Suppression of fixed
obstructions.
-
Greater value in the solution based on
pre-and post-sales support.
-
Convenient Communication using HART® or PROFIBUS PA.
-
Greater safety and convenience from
programming flexibility.
|
