The global dairy industry is growing, and one of the dairy producers’ biggest challenges is to maintain high product quality, while also increasing efficiency and minimizing waste and downtime. Recently Philip Edwards wrote an article on this topic for What’s New in Food Technology and Manufacturing titled, “Conductivity Measurement: A Hidden Key to Dairy Industry Success.” Below is an excerpt from this piece:

NZCattle2_lessgreenTo ensure this consistent product quality, the equipment used in the manufacturing of dairy products is not only made from the highest grade of material, but also needs to be cleaned and maintained in such a way as to minimize any possible contamination when changing from one product to another or from one batch to another. This process is called CIP (clean-in-place).

To remain competitive, it is important to minimize production downtime without compromising on the safety and quality of the end product. In the CIP process, conductivity measurement is used to determine how effectively equipment has been cleaned and flushed. Conductivity in CIP picks up the change in the electric conductivity of a sample stream to indicate when a flushing process has started and ended. On a rinse cycle, for example, low conductivity indicates that all chemicals in the process stream have been flushed out and it’s ready for the next batch of product.

An Interesting Case History
A major global dairy company with plants around the world was experiencing challenges with its liquid analytical systems, particularly as related to CIP. CIP systems thoroughly clean wetted components such as tanks, vessels, fermenters, process lines and inline sensors. The CIP process controlled the flow of pre-rinse, wash and post-rinse cycles, which include caustic rinse, acid rinse and water rinse cycles.

Conductivity sensors are a critical component in the design of CIP systems. The various cleaning solutions have more conductivity than the water used for flushing and final rinse. Since many systems are a ‘re-used design,’ the sensor can monitor the strength of cleaning solutions as chemicals get used up through successive cleaning cycles. Conductivity measurements can indicate the need for replenishment.

Any sensors that have to withstand CIP and sterilization must be able to function under very harsh conditions — not a simple requirement for a sensitive analytical sensor. The dairy company was experiencing up to a 50% failure rate on sensors each year, at an approximate cost of $1,200 per sensor. Much worse, however, was the cost of plant downtime — up to $100,000 per hour. The significant failure rate called the reliability of every sensor into question after a short usage period. As a preventive measure, every conductivity sensor was replaced at the end of the season, which required another CIP cycle to be performed, adding even more costs and delay to production. It was preferable, however, to the possible dumping of milk product that would have to occur in the event of a sensor failure during processing.

To learn more about the unique solution the dairy producer implemented to overcome these challenges, click HERE to read the full story.

by Barry Wallen

Hello, and welcome to Analytic Expert! I’m Barry Wallen, Senior Sales Engineer at Emerson Process Management. Today I’d like to talk about measuring pH in corn slurry in an ethanol plant. Historically, this has been a tough measurement due to a variety of factors including heat, viscosity, abrasion, and contents of the stream. The problems included shortened probe life, lack of accuracy across a useful pH range, and sluggish response to process changes. The use of a sodium reference pH sensor made meaningful 2 point calibrations impractical. The need is for accurate pH measurement across a wider range, and quicker response times.

Here’s a meaningful solution. The Rosemount Analytical 3300HTVP and the 1056 analyzer have been performing well in dozens of ethanol plants beginning with a trial in Hudson, South Dakota. With these technologies, plants are getting consistent accurate pH values as well as longer sensor life.

The 3300HTVP is a robust sensor with a rebuildable reference electrode. This extends the life of the sensor as the reference electrode is usually the first part of the sensor to “die.” Typically, plants are doing a reference junction rebuild monthly and seeing probe lives of about a year.

Generally, the electrode is mounted in a tee in a recirculating loop beside the tank; however there is a retractable version that can be mounted through a ball valve directly into a tank. Ideally, the fins on the electrode protecting the glass bulb of the sensor should be oriented so they are upstream and downstream, not on the sides of the stream. This gives the glass measurement electrode protection from abrasion caused by the slurry as well as any metal pieces that may have made it this far into the process.

On initial power up, the 1056 will walk through a quick start menu. This menu allows operators to rapidly confirm a few parameters including language, measurement (in this case, pH), temperature units, and operating Hertz. The manual includes detailed instructions on advanced set up – there is very little that would need to be changed. The display allows for two (2) large display items (usually pH and temperature in a single channel unit) and four (4) small ones. These are all user selectable. For additional information on the application, please click HERE.

You can then perform an initial calibration and start receiving reliable accurate pH values.

For complete instructions on operation, maintenance, and steps in rebuilding the reference electrode, please click HERE. And for additional information on other food and beverage applications, please click HERE.