Stainless steel material has been the most popular material for food processing machinery. What makes the stainless steel suitable for food?  The first and foremost must be the corrosion resistance. The stainless steel material can remain clean and shiny in the atmosphere, and the metal content would not be released into the food. ASTM 304 is the most common and popular stainless steel grade. The oxidized chrome film on the surface of the stainless steel can be a protective layer against exposure to oxygen and water. Its smooth surface and non-absorbent surfaces make it easy to clean.

The stainless steel can also sustain a wide temperature range and sudden temperature changes. And it’s easy to be formed, welded, and machined to different shapes.

Types of Stainless Steel Equipment

Spiral freezer

Spiral freezers are one means of refrigeration that are popular with food processors given their compact, spiral belt and their ability to freeze large amounts of products with longer dwell times. Spiral blast freezing of food products is the most energy-intensive process in a typical frozen foods manufacturing facility with air temperatures regularly in the range of -10°F to -50°F depending on the type of product to be frozen.

Unlike tunnel freezers, which require a long, linear wire-mesh belt to convey products through a sub-zero blast-freezing room, spiral freezers use self-stacking, multi-tiered belts to maintain product quality and minimize the refrigeration space required in the plant. Most modern spiral freezers offer a level of customizability and are generally fairly easy to install on the plant floor.

A spiral freezer comprises of spiral conveyor, evaporator, chain drive system, insulated enclosure, control panel, and CIP(clean-in-place) system.

Fluidized Bed IQF

There are several models fluidized bed freezer models to suit a variety of fruits, vegetables, seafood and other products. We provide efficient, hygienic and affordable IQF solutions to our clients.

The airstream is in an upward direction and the velocity of the air is adjusted to just lift the product off the belt and this also causes the product to flow.

The product remains separated during freezing, as each particulate is lifted off the belt and tumbles in the air. It freezes while remaining separate from neighboring particles.

The technology allows minimum product water loss and a large freezing capacity of up to 6 tons/hr.

The food particulates generally of a uniform size are placed on a mesh conveyor, the airstream is in an upward direction and the velocity of the air is adjusted to just lift the product off the belt and this also causes the product to flow. There is a change in the elevation of the conveyor, the solid particles begin to act like a fluid as they are submerged in the air.

As the product moves in the fluidized bed, it comes in good contact with the air, there is an excellent heat transfer between air and product.

One can achieve convective heat transfer coefficients of between 30 and 60 w/m2k.

The product remains separated during freezing, as each particulate is lifted off the belt and tumbles in the air. It freezes while remaining separate from neighboring particles. Particulates are frozen in an individual manner, and we call it IQF. We can get similar results on a regular belt freezer, but in a fluidized bed you have better separation of the particulates and individual quick freezing.

Some of the common products that are frozen in a fluidized bed freezer are strawberries, blueberries, diced meat, peas, beans, and French fries.

Continuous Fryers

The “Square” Immersion fryer is suitable for frying meat products, including chicken, shrimp, meatballs, etc.

Heat transfer oil enters and leaves the heat exchanger at the outlet of the fryer.

The cooking oil temperature is precisely and constantly controlled by the PID control system, via regulating the valves on the heat transfer oil pipework.

Benefits of Using Stainless Steel Equipment

1. The high flexibility of stainless steel allows engineers to create increasingly efficient food processing machinery. This flexibility allows machinery to be shaped to the various processes desired; once constructed, its inherent toughness and strength ensure that it will stand the wear and tear of many years of heavy use.

2. Corrosion-resistant, it can resist the most powerful cleaning products and extremely high water temperatures, thus maintaining the highest hygiene standards. The smooth finish also minimizes any hygiene hazard posed by bio-films.

3. ease of cleaning means that stainless steel remains the preferred material for environments where strict hygienic conditions are important; commercial kitchens, fast food outlets and cafes and restaurants. Meanwhile, its corrosion resistance means it does not affect the taste or appearance of foods.

How to Choose the Right Stainless Steel Equipment?

1. Capacity

If the production capacity is larger than 1000kg/hr. normally the spiral freezer is highly recommended. It has multiple belt tiers and makes the best use of the height, thus minimizing the footprint in the workshops. The optimized air flow can reduce the freezing time by at least compared to the traditional chamber freezer. If the capacity is less than 1000kg/hr, the chamber freezer and linear freezer can be chosen as well, for their lower cost and short manufacturing time.

2. Type of Food and Beverage

The size and type of the food will also decide the equipment to be selected. The spiral freezer is quite versatile, it can freeze the product of individual weight range between 10g to 5 kgs, and still keep a fast freezing time between 15 minutes to 3 hours. When freezing small granular products, like vegetable dice, fruits, and fried rice in a large capacity of up to 15 tons per hour, the fluidized bed IQF freezer can be very efficient and cost-effective. It can freeze the product in less than 10 minutes, and guarantee a good result after the freezing.

Square Technology’s fryer is very suitable for chicken nuggets, meatballs, shrimp, etc. However, for products like potation chips, and donuts, there will not be different types of fryers.

3. Space

In regard to space-saving, the spiral freezer and spiral oven are always space-efficient compared to the linear freezer and linear oven. However, it is also determined by the factories’ unique space and layout. If the factory has limited ceiling height, but a very long workshop length, then the linear equipment will suit better in the the factory’s processing line.

4. Budget

For those food processors who have a limited budget, but want to start the business from a relatively small investment, normally they can choose a freezing chamber, linear freezer, and commercial fryer to start up. However, the production rate of these machineries will be less than 500kg. For a big plant that normally produces food in a quantity higher than 1000kg/hr, the spiral freezer or long linear freezer and continuous freezer will be a necessary investment, and the budget for such will be anywhere between USD 500,000, to USD 3 million.

Who is Square Technology Group

Square Technology Group Co. Ltd (formerly Nantong Square Freezing & Heating Mechanical Equipment Co. Ltd.) is a listed company in SquareShanghai-stock Exchange. The company has been manufacturing freezing systems for over 30 years and is the largest freezer manufacturer in the world.

Our manufacturing facility is located in Nantong, China, with some 1300 employees and 64 acres of land. We serve a wide range of food processing industries and can draw from our extensive experience to provide our customers with the best value and ensure maximum profitability.

The product line includes spiral freezers, fluidized bed freezers, plate freezers, tunnel IQF, refrigeration units, cold storage, air coolers, ice machines, etc.