Industrial Utility Efficiency    


Electricity and compressed air play an important role in the thermal and kinetic processes for everything from mixing and extruding the ingredients, deep-freezing to -13°F (-25°C), dipping into various chocolate coatings through to final packaging. Energy efficiency is therefore right at the top of Unilever’s list of priorities. As part of the Unilever Sustainable Living Plan, this global corporation has succeeded in saving more than $186 million in energy costs from efficiency improvements in production alone since 2008.
By addressing inappropriate uses of compressed air and making changes to the compressed air production side of their compressed air system, a distiller of fine alcohol products reduced its energy consumption by 30%, saving $16,600 per year in energy costs - with more potential savings possible.
For more than 20 years, Hungarian-based Doroti Pack Ltd. has specialized in the production and servicing of state-of-the-art packaging machines. Their focus is on developing, manufacturing, producing and selling premium-quality packaging equipment, including their line of DorPack thermoforming machines which are often used for food products such as fresh meat, fish, dairy products, bakery ware, confectionery and ready-cooked foods. Dorati Pack chose to incorporate Aventics pneumatic components in latest thermoforming machine for optimal productivity and machine longevity.
Experienced auditors become wary when they see desiccant dryers installed in customers’ plants. These dryers are required when a plant needs instrument-quality compressed air, or when compressed air piping is exposed to freezing temperatures. However, while desiccant dryers can gain this level of quality, the energy cost of stepping up from a dewpoint of 35 oF to a level of -40 oF increases quite considerably. To attempt to reduce the energy costs of drying to these low levels, heated blower desiccant styles may be used. This article describes three common desiccant dryer types, as well as some experiences, good and bad, with heated blower types.
This major food manufacturing plant in the Midwest uses compressed air and onsite nitrogen generation to operate multiple snack production and packaging lines. The plant spends an estimated $430,344 annually on energy to operate its compressed air system based on an average rate of 4.5 cents per kWh.
A food processor in Western Canada hired an auditor to assess the energy efficiency of its compressed air system. The results revealed surprises about the operation of some important elements of the system, and detected that the air compressors were having control gap problems. Additionally, the audit led to initial energy savings of $20,000 – and identified the potential to achieve overall operational savings of 45%. The following details some of the audit findings and results.
Many food processing plants are already using oil-free compressed air at a low-pressure dewpoint. This has required the use of two-stage oil-free screw air compressors, centrifugal air compressors and other technologies, as well as regenerative dryers of one type or another. The most common oil-free air compressor in industry is the two-stage “dry screw” machine and the most common regenerative dryer type is the heatless type. These are combined in many food processing, pharmaceutical, and high-tech plants.    
Machines for filling milk or juice must often work around the clock. Given the critical importance of uptime, Elopak opted for Aventics food-compliant pneumatics when developing its E-PS120A - the first fully aseptic filling machine for gable top packaging. With an output of up to 12,000 cartons per hour, disruptions and downtime are not welcome with the aseptic filling machine.
Gaseous nitrogen is used in a variety of systems and processes in the food manufacturing and packaging industries. Often regarded as the industry standard for non-chemical preservation, nitrogen is an inexpensive, readily available option. Suited for a variety of uses, Nitrogen needs to be monitored for purity and potential contaminants. Depending on the type of use, the distribution channel, and the required purity levels, different testing plans should be implemented to ensure safety.
As many well know, system measurement is essential to ensuring a compressed air system is running efficiently and effectively, with good air quality and adequate pressure.  This is also well understood by a multi-national food company (name has been withheld to protect the innocent) who started a focused effort to measure and improve their compressed air systems in their many processing plants worldwide. 
A flour based frozen foods manufacturer orders a compressed air efficiency audit. The audit establishes the cost of compressed air at $0.27/1000 cubic feet. The study finds the 116 pulse jet dust collectors represent the greatest opportunity for compressed air demand reduction and energy cost savings. A dust collector optimization study/service is suggested and the customer agrees to proceed. In this facility, pulse jet dust collectors are used to filter dust from raw materials entering the plant, for conveying and mixing of ingredients, and for the final packaged finished products leaving the plant.