Skip to main content

Events

Categories

Chemical Engineering

A new nozzle technology for fluid-bed granulation

| By Mary Bailey

Romaco flexijet nozzle

Source: Romaco

The new FLEXIJET® nozzle offers easy operation, fast cleaning and low-cost maintenance for short granulation processes. In fluid-bed processes, the spray nozzle plays a crucial role in introducing the spray liquid into the fluidized product and either granulate or coat the powder, depending on which process is required. FLEXIJET has been specially developed for fluid-bed granulation, with a focus on simple handling and easy nozzle cleaning. Granulation demands considerably less time than fluid-bed coating processes, which is why the spray nozzles used for granulation have to be dismantled and cleaned quite often. The FLEXIJET® was therefore designed specifically with short batch-processing times and frequent product changes in mind. To remove the nozzle, all that is needed is to undo one screw — the device can then be detached and dismantled into its ten individual parts. Refitting cleaned components is also extremely simple and can be completed very quickly without checking and adjusting the spray gaps.

This new, simpler handling is partly due to the design of the spray gap, in which a flexible plastic membrane seals the circular gap from above. The flexible cap lifts solely through the pressure of the incoming liquid, and ensures excellent distribution even at low spray rates. If the process has to be interrupted, the spray liquid is pumped back, causing the membrane to be sucked in and to securely seal the spray gap. This prevents the gap from drying out and deposits from forming, which could block the nozzle when the machinery is restarted and therefore put the process at risk. Maintenance of the FLEXIJET is also easier because all nozzle components and wearing parts are available to reorder at any time and can be replaced by users themselves without the need for specialists. Besides granulation, the FLEXIJET® nozzle is also recommended for hot-melt coating applications, as no liquid evaporates here and batch processing times are relatively short.