Dale Spiral Systems & Bakery Automation is nearing completion of its first-ever carton cooler, which has been in development for four years.

Project manager Heinrich Hattingh tells Engineering News the company has been specially engineering the equipment for use in a food manufacturing facility to cool down dairy product from around 30 °C to 11 °C.

He explains that the machine can accommodate 96 t of product, at a retention time of 24 hours.

The carton chiller comprises 61 racks, each containing eighty 20 kg boxes. It has been designed for cooling using ammonia gas refrigerant and 16 fans, while hydraulic pistons are used to drive the racks through the machine.

Dale will start the month-long installation process at the customer’s factory early in April.

Hattingh says the company aimed to manufacture a low-maintenance chiller, which only requires routine oil and filter changes.

MD Chris Dale mentions that the carton chiller is also suited for the chicken and processed meats industries, and adds that the company intends to supply these markets as well.

What gave the company the edge during the tender process for this customer was its long-standing ability to design for accessibility, efficiency, serviceability and cost effectiveness, says Hattingh.

The company started manufacturing spiral technology 23 years ago and acquired its 7 000 m² manufacturing facility almost nine years ago.

Dale points out the company is renowned for its refrigerated bread conditioning technology, but offers the full spectrum of bakery automation equipment.

The company’s equipment is responsible for cooling and conditioning more than 428 000 loaves of bread every hour of every day.

Dale has often exported equipment to other sub-Saharan African countries, Australia and the UK in addition to serving the local market.

WHAT GOES AROUND

Dale Spiral Freezers are designed around a concept familiar to the food process industry, incorporating standard equipment which is well proven in continuous production.

However, design changes have been instituted in the construction of the conveying system to improve accessibility, flexibility, mechanical performance and hygiene.

Airflow design and evaporator selection has also been revised to enhance product freezing and product weight loss. Dale Spiral Freezers have quickly gained a reputation in the industry for achieving product core temperatures in given retention times, the company points out.

In designing the equipment, emphasis has been placed on flexibility such that each machine can be specified to comply exactly with customer requirements.

The flexibility is not limited to choice of belt width, type or effective belt length but applies also to the specification of materials, designation of scope of supply, and installation.

Both internal and external surfaces of the drum assembly are made from stainless steel for hygiene and durability purposes. In the case of smaller machines, the drum assembly can be of a welded construction and therefore delivered as a complete unit.

In case of all other machines, the drum assembly is delivered in sections for ease of transportation and especially where installation access is tight.

Dale’s own Blue Belt conveyor belt systems are often preferred over stainless steel belting. Both heavy and light products, which are either packaged or raw, can be frozen on plastic belts depending on the type of belt selected.

Belts can be fitted with unique lane dividers to keep products apart or to transport different products at the same time through the spiral from and onto separate conveyors. Most of the spirals supplied by Dale have the company’s own Blue Belt plastic modular belts installed on them and the company is proud to have it installed on two of the biggest spiral freezers in the southern hemisphere with throughputs of 7.5 t/h and 8 t/h of individually quick frozen chicken.

Optional hygiene systems can be requested and designed into the system from the onset. Full or partial cleaning-in-place systems can be accommodated to clean the entire spiral and evaporator or a simple belt washing system can be provided depending upon the customer’s preference.

Meanwhile, the company offers two types of carton freezers for industry – single retention time (SRT) freezer two pass and a variable retention time (VRT) freezer multiple pass. The latter is capable of freezing or chilling different sized products at different retention times.

These systems can be designed and manufactured in a variety of orientations to suit the company’s factory layout. Airflows have been extensively simulated to optimise freezing times, reduce fan power consumption and provide longer cycle times between defrosting.

Sequential evaporator defrosting is available to afford the system longer production times.

The company explains that intelligent loading conveyors gap products enter the chiller or freezer to ensure air circulates around all sides of the cartons when loaded.

Dale’s SRT freezer can be designed for throughputs from 1 t/h to 14 t/h, while providing precise temperature control.

The VRT freezer can be designed for throughputs from 4 t/h to 40 t/h.