Mercer Stainless has been well known in the New Zealand food industry for many years as a quality supplier of tanks, silos and pressure vessels. What is less well known is that within the team, there is also a group of experienced engineers capable of designing and building conveying equipment including spiral coolers and freezers. Spiral coolers and freezers are typically used in the food industry for efficient cooling when there is limited floor space and to maximise heat transfer. As energy costs tend to be a significant operational expense for most firms, the installation of a spiral conveyor provides excellent payback and operational efficiency.
Mercer Stainless’s spiral coolers are available in many space-saving configurations to best suit the user’s application. Using high quality components and reputable partners with regard to belt supply, Mercer's spiral conveyors are the equal of any supplier in the industry. The spirals are suitable for raw products (such as snack foods, dairy products, bakery products, seafood, poultry/meats, etc.), bottles, ready meals and cartons. They can be equipped with belt washers (clean-in-place units) to ensure the optimal hygienic environment. The durable stainless-steel or galvanised-steel construction is suitable for continuous production in harsh wash-down environments. The efficient and smooth drives result in uniform cooling of products to minimise process time. Mercer will work with the customer to scope their spiral, and then design, construct and install a specific solution. The following configurations are available: single and twin spirals, coolers and freezers, elevators/lowerators, low and high tension systems.
As for the drive system, there are chain drives and pinion and ring gear drives available. The chain drive is an inexpensive system to manufacture and is very easy to replace. While this system is a lower cost option, it will require more maintenance than the pinion and gear drive. The pinion and ring gear is a smooth and quiet system. The load carrying capacity of the slew bearing can minimise dependence of additional structures for support. The simple design results in a longer service life and is better suited to below zero conditions. We can supply a design that incorporates a quick release motor mounting system for servicing, reducing downtime and maximising productivity.

Cooling Tunnels
In addition to spiral conveyors Mercer Stainless can custom design and fabricate a cooling tunnel for your particular application and process. Our cooling tunnels are suitable for a variety of applications, and can be used as part of a pasteurisation and cooling system. Mercer Stainless cooling tunnels have automatic infeed and outfeed units and the company offer to help integrate them into the customer’s existing plant and control system.
The modular design means a minimum of disruption to the plant during installation and also means the machine has the smallest possible footprint, reducing capital investment and impact on buildings. Multiple cooling zones and a split conveyor system allow for cooling several different products at the same time, maximising the use of capital equipment and operational staff.

There is a specific design for glass products which includes a heating section within the tunnel, alleviating thermal shock on the glass and eliminating breakages, minimising operating costs and wastage. Suitable Applications include glass bottles and jars, plastic bottles, metal cans, cereals, snack foods as well as metal parts. On the list of standard features are items such as stainless steel or plastic modular belt, access hatches and removable hoods to allow ease of access for cleaning and full installation and commissioning. The cooling tunnels are designed to use the customer’s existing cooling medium. To maximise service usage efficiency, Mercer Stainless has included full coolant reuse and retrieval in the system design.
Mercer Stainless has extensive experience in the design and construction of all types of standard conveying equipment, including powered roller, belt over deck and plastic modular belt conveyors. Plastic modular belt conveyors are becoming more popular within the food industry because of their robust construction combined with easily cleanable fabrication.

This twin spiral freezer operates at -38 degrees Celsius. It features 1,200 m of conveyor belt and comes with a retention time of two hours. The capacity is 2,200 kg/hr.

Partnership
Mercer Stainless has an exciting partnership with an American company called NBE. NBE specialise in bulk materials handling equipment for difficult applications. Incorporating 1,000 kg bags and 220-l drum filling and emptying equipment, NBE has a range that can be configured in any way that is required. Recently completed projects include a bulk bag emptying system for a national defence contractor that dealt with an explosives mixing plant that required careful handling and separation of ingredients up until they reached the mixing part of the process. NBE have also completed a variety of projects for the nut industry, including sorting walnuts and macadamia nuts.
NBE have just released a range of sanitary equipment, meaning that all their designs can be made from stainless steel and are suitable for situating within a critical hygiene part of the process if required. This is in addition to a complete focus on ease of use and operator safety to minimise the risk to operators and ensure maximum productivity while providing the most ergonomic solution.

Email: pmerkel@mercers.co.nz