The Integrated Filter Dryer (IFD™)

The Integrated Filter Dryer (IFD™) is a spray dryer with integrated filters and fluid beds. The Integrated Filter Dryer is based on proven spray dryer unit operations, such as:

• The atomization can be achieved by a rotary atomizer or a pressure nozzle. Pressure nozzles usually used for high fat containing products and/or products with high protein content. Rotary atomizers are used for all kind of products (i.e. concentrates with crystals, low fat, high mineral, etc.)
• The feed systems are the same as in normal spray dryers i.e. concentrate preheating, filtration, homogenization, and high-pressure pumps.
• Drying air filtration, heating, and distribution using an air disperser suitable for rotating or vertical air streams.
• Drying chamber designed to ensure hygienic operation conditions and to maintain lowest possible heat loss. This can be done by installing insulation plates and panels.
• The integrated fluid bed is designed as a combined back-mix fluid bed for the drying and plug-flow fluid bed for the cooling. Between the back-mix bed and the surrounding plug-flow bed there is an air gap to avoid heat radiation. The new patented Niro BUBBLE PLATE™ is used - the BUBBLE PLATE™ is the one of the latest developments by Niro for the fluid bed technology. Since it is non-sifting, it does not allow heat sensitive products to fall through the plate perforations. The plate controls powder movement by means of the airflow. It has no surface imperfections and has been accepted by USDA / 3A and EHEDG.

The bag filters inside the Integrated Filter Dryer (IFD™) chamber (drying chamber).		The reverse jet air nozzle installed inside the drying chamber of the Integrated Filter Dryer (IFD™).

The Integrated Filter Dryer (IFD™) exhaust air system is new although it is still based on the same philosophy as the SANICIP™ CIP-able Bag Filter. The fines collection system operates with particulate filters integrated in the drying chamber. The filter bags are supported by stainless steel cages mounted in the ceiling of the drying chamber. These filter elements operate with blow-back air cleaning systems identical to those used in the SANICIP™. The bags are purged one by one, or four by four, by compressed air blown into the bag using the reverse jet air nozzles. This gives a regular and frequent release of powder into the integrated fluid bed. The bag filters has been approved by USDA and 3A.

The pulsing of the reverse air jet nozzle with compressed air and water enable the confined and trapped powder inside the filter bag to be washed out.

The reverse air jet nozzle has a double function:

Clean water is injected through the reverse air jet nozzle and pulsed by compressed air into the inside of the bag and squeezed through the cloth material. This feature is key as it is quite important to wash-out the trapped powder from the outside only.

To clean the inside of the drying chamber ceiling, a specially designed CIP nozzle is used - during the drying operation the nozzle is purged with air to keep the area free of deposits and during cleaning it is used as a normal CIP nozzle. The clean air plenum is cleaned using a standard CIP nozzle.

Advantages of the IFD™ Plant

Product:

• Higher yield of high-grade powder. In dryers with cyclones and bag filters, the bag filter yield is often considered second-grade - this normally account for approximately 1% of the production.
• Less mechanical handling of products (in ducts, cyclones and bag filter) and no external recycling of fines is necessary, since the air flow pattern inside the dryer ensures an optimal primary and secondary agglomeration.
• Improved product quality - the Integrated Filter Dryer (IFD™) can operate at lower exhaust air temperature compared to a conventional spray dryer. Therefore, you can achieve a higher drying capacity with the same amount of drying air.

Safety, environmental and projecting:

• Simpler safety protection installations (as the drying process takes place in one unit)
• Fewer components to protect
• Lower maintenance costs
• Simpler plant layout
• Reduced building size
• Simpler supporting structure
• Reduced possibility of powder leakage into working area
• Easier cleaning operations as surface area in contact with the product is reduced
• Less effluent discharge during CIP
• Less powder emission, down to 10-20 mg/Nm3
• Reduced energy consumption, saving up to 15% of the power consumption
• Reduced noise level, due to reduced pressure drop over the exhaust air system