“Many companies apply spiral freezers incorrectly with inefficient and costly results” explain Roy Kools of Befeko and Johnathan Ball of NH3 Ltd. This Dutchman and South African claim that their Automatic Tray Freezer (ATF) unit, which is based on a flexible and compact shipping container platform, provides a vast improvement to more than 40% of spiral applications.
“Spiral freezers are good for small naked product but, larger or packaged product with long retention times render the spiral freezer model of freezing ineffective, inefficient and not applicable” say Roy Kools and Johnathan Ball. The newly developed product is a miniaturised version of the well known and existing Automatic Carton Freezers (ACF) also built by NH3 Ltd.
The English company, NH3 Ltd which was established by Johnathan Ball in 1995, designs and builds automatic freezing / chilling units using refrigerants carbon dioxide (CO2) and ammonia (NH3). The fully automatic system utilizes a sealed, refrigerated area and has a separate small (product size) entrance and exit which close automatically when not in use.
“It is, in fact a kind of compact cabinet with movable shelves” he explains, “they move through the cabinet as the product is frozen”. Up to five products of different sizes and / or package types can have different freezing recipes at the same time. The packages are precisely spaced to limit the amount of air circulation required and consequently minimizing the fan requirements. An industrial computer keeps track of the products progress and location. Ball says, “if at a given time only one product is required for packing then this specific product can be discharged at the push of a button”. The small containerised versions hold between 12 and 28 tonnes.
The larger freezers compared with conventional shock freezers, use less man power, are more efficient and have smaller footprints. These machines are applied between the end of production lines and frozen storage or in public cold store operations. In addition, the carton presentation is improved due to reduced handling. These larger machines freeze / chill between 85 and 350 tonnes per day and are used for chicken, beef, pork and fish products. A permanently closed freezing machine does not cause slippery, wet floors and isolates forklifts to non pedestrian areas.
Vriescentrale Asten
NH3 Ltd has three types of freezers; the Automatic Carton Freezer (ACF) and two Automatic Tray Freezers (ATF), a large a mini version.
In the Netherlands, such a system was implemented about four years ago at Vriescentrale in Asten. The old Freon freezer was removed and replaced by an ACF that freezes using carbon dioxide (CO2) and ammonia (NH3) refrigerants. “This installation took just nine weeks” explains Johnathan Ball. “After the installation, measurements revealed that the new system consumed 45% less energy than old conventional freezing systems and it freezes in half the time, which contributed to a reduced energy bill.”In addition, the ACF system installed at the factory has a 185% larger capacity in the same footprint of the old freezer which it replaced. According to Johnathan Ball’s calculations an average of 35 to 50% of the interior of any ACF is filled with product compared to 11 to 20% in conventional spiral freezers. This substantially reduces the footprint.
Containerised Version
Now that the system has been proven, Johnathan Ball and Roy Kools have developed a containerised version which solves the problems of the spiral freezer and fills a gap in the market place. The entire system is factory assembled, wired and tested before being sent to site. Only the insulated enclosure, conveyors, power supply and refrigeration connection need to be completed on site. They are delivered to site via a container truck.
The ATF100 model is 3 metres wide, 3 metres high and 40′ (12mtrs) long. The ATF150 and 200 are 1.5 or 2 times higher. All of these units can be transported by road without escort and craned into position.
Placement and interrogation into the existing production systems is a lot simpler and faster than normal, reducing delays and down time on production lines.
The ATF range also addresses some of the longstanding spiral freezer problems. The ATF in/outlets are at the same air pressure. Spiral freezers have different in/outlet air pressures causing inefficient cooling of the surrounding area and frost within the spiral. Costly spiral freezer belts are replaced in the ATF with inexpensive shelves.
South African Johnathan Ball moved to the United Kingdom in 1987 and established NH3 Ltd in 1995, as a company that installs and maintains ammonia refrigeration systems. The company also builds the large Automatic Carton Freezer (ACF) and the containerised versions in house. Roy Kools has many years of experience in the chiller industry. His company, Befeko Technique Nieuwegein specialises in refrigeration systems and his clients include industrial bakery Hema.
