Image Credit: ABB Measurement & Analytics
Milk is a commodity widely consumed throughout the world, in spite of its short shelf-life and high perishability.
The capabilities of advanced processing and pressure measurement instrumentation have considerably enhanced the stability of milk-based goods that are vulnerable to colloidal degradation and toxic bacterial growth over very brief periods.
This is mainly attributed to the complex biological composition of raw milk, which contains lactose, fat, enzymes, vitamins, proteins and various minerals along with many trace elements.
Such constituent parts act differently under different thermodynamic conditions. Dispersive fat globules readily migrate via the liquid state of milk—normally at higher rates under high temperatures or ambient pressures.
Agglomeration of such fatty particles will result in the separation and spoilage of milk; hence, milk should be subjected to steady pressure and temperature measurement throughout processing.
This article comprehensively explores dairy processing, focusing on the significance of pressure measurement.
Pressure Measurement During Pasteurization
Raw milk can be directly subjected to the pasteurization process after delivery, or after a cooling-down period where it is preserved in agitated tanks at regulated temperatures of around 41°F (5°C).
Pressure measurement for dairy storage tanks would need a transmitter and a sensor with hygienic connections to prevent the possibility of dangerous cross-contamination. As soon as the raw material reaches appropriate conditions, it is exposed to thermal processing.
To improve this process, stainless steel should be ubiquitously used for all the instruments employed in the processing chain, instead of just the wetted parts and surfaces. It is essential to use process connections with valid certifications, such as 3-A, EEHDG, OIML-117, or MID, for use in the dairy sector.
ABB offers both 261 and 266 pressure transmitters with type DIN11864, DRD, or Varivent process connections certified for dairy production applications. These pressure transmitters are extensively used in pasteurization processes.
Pasteurization is a universal process in the dairy sector. This process was originally developed as a means for sterilizing beverages, such as wine, but was later reckoned useful for expanding the shelf life of processed milk.
The process is performed by heating milk to temperatures of 165°F (74°C) for up to 30 seconds before it is cooled again. This effectively kills dangerous microbes before the milk can permanently destabilize. Pressure measurement is needed to sustain overpressure conditions, which guarantees that both treated and untreated milk do not make contact.
Pressure measurement of the heating cells should also be performed to reduce the adverse build-up of pressure that could play a role in costly downtime and mechanical failure.
Even today, traditional milk processing uses a form of pressurized denaturation to obtain a homogenous product that conforms to regulatory standards. As soon as the raw milk has been pasteurized and standardized, it is allowed to pass via a sieve under pressure to isolate fatty particles and redistribute them across the liquid state.
This needs continuous flow pressure measurement within tight degrees of tolerance to make sure that the final product reaches an optimal consistency without any unwanted heterogeneities.
An internal vegetable oil, like Neobee, or white oil, should also be used in process instruments to meet Federal Drug Administration (FDA) compliance, ensuring that the process will not be contaminated.
Pressure Measurement with ABB
ABB is one of the world’s biggest suppliers of test and measurement instrumentation for commercial and industrial applications. The company has delivered a wide selection of pressure measurement devices for milk processing and dairy farm applications.
This information has been sourced, reviewed and adapted from materials provided by ABB Measurement & Analytics.
For more information on this source, please visit ABB Measurement & Analytics.