Drying technology FAQs for food Processors

SELECTING a drying method requires careful consideration, and  the options are as extensive as they are diverse. In food processing, the goal is to maintain the highest level of  nutrients, consistent quality  product, minimise energy, and ensure the drying process keeps out unintended microbials.  But finding the right technology for your operation takes time and research. You can start by asking questions. What is the particle size that you’re working  with? What is the physical structure of the food material when wet or dry? Does it need to be continually processed or batched? Science, field experience, and processing knowledge should all play a role in the selection  process. Following are eight questions to consider.

1. Which convection dryer is right for my processing?
Convection dryers use hot air for heat and mass transfer.  When hot air comes into contact with the product being dried, air is evenly distributed over and around the product such  as extruded cereal  or fruit.  And, there is no one convection dryer that fits all. Some dryer technologies are well suited for processing small particles like  spices, whilst some can’t handle sticky material like infused fruits and still others only handle liquids. Your product characteristics will dictate the best drying technology for your operation. To help you get started, following is a list of the kinds of food products alongside the dryer types generally recommended for processing them.

2 .What method of product conveyance willprovide the optimum outcome?

The method of product conveyance is the biggest difference between drying technologies. For instance, conveyor dryers or the tray/tunnel dryers are gentle on  products  like  fruits  and  vegetables, whilst the fluid bed or rotary dryer is much rougher on products like by-products or toasted  cereals  in  order  to  bring  about desired characteristics.

Some say the need to consider product conveyance is almost as fundamental to food processing as safety.For instance a fragile snack food will be damaged if fluidised or tumbled.  For apple pomace, however, the tumbling action of a rotary dryer might be a requirement to breakup clumps in order to subject new surfaces to the airstream.
 
3 .What kind of heat sourceis available for my processing operation?

There are many possible ways to heat air in a convection dryer, such as burners, steam coils, thermal oil coils or waste heat from another process.  The availability of fuel at your location will usually dictate the type of heating to use.  Natural gas is a clean-burning fuel that can often be direct fired in the air stream, even in food dryers. As a result, it’s the easiest fuel to use in convection dryers. Other fuels such as oil or biomass will often be burned in a boiler instead of directly in the dryer. Steam is a great way to heat air in a convection dryer, using steam coils; however,  achievable air temperatures are limited to below 175°C unless very high steam pressures are used. This can often make  some dryer technologies such as rotary dryers impractical when only steam is available because they require higher temperature air to be efficient and to reduce dryer size.

4. How can I maintain an energy-efficient process?
Evaporating  water takes a significant amount of energy.  Regardless of the drying technology you decide to use, it will likely consume the most energy used in your plant.Therefore, you’ll want to minimise it as much as possible. ThereNike Air Max Lebron