Powder density, particle size, solubility and stability are important characteristics of optimum quality dry powders, and multiple factors are often to blame for causing powders, including milk powders, to be of inferior quality.
Spray drying is a critical stage in the development of powder, and updating to more technologically advanced spray nozzles is often all that’s required to correct issues with powder quality and consistency. The solutions are generally in the details, and new technology and research can correct issues that have been causing disruptions, delays and higher expenses in spray drying processes.
Problems such as inefficient dryer configurations, powder formulation, product build-up (bearding) and even wear part misalignments can be the culprits that cause problems with powder production.
The best spray nozzles are those that are totally smooth in the fluid zone – that is, where the swirl and orifice reside there are no O-ring grooves, threads or locators that can trap debris or interfere with flow. Using old nozzle technology means cleaning is problematic and there are disruptions to the flow dynamics through the nozzle, which make it tough to produce consistent, precisely defined powders.
Another characteristic of traditional spray nozzles that contributes to low-quality powder is the nozzle design. In regular conventional nozzles, product build-up drips onto the chamber and becomes scorched particle deposits, which adversely affect powder quality.
The ideal nozzle design should have an outer face profile that reduces product build-up or bearding. This can be achieved by moving the O-rings away from the fluid zone and into the orifice disc. This revolutionary concept has already been designed and created by a cutting-edge engineering company.
Traditional nozzle designs also have misalignments between the swirl chamber and the orifice. The decentralised parts create inconsistent spray drying and this affects the powder quality. But more innovative technology by the same company has created a solution for this problem too.
The Click&DryTM system created by Spray Nozzle Engineering features a Concentric Clasp Technology that holds the swirl and the disc in perfect alignment inside the nozzle cap, eliminating misalignment and delivering an excellent spray performance. The pressure and flow is consistent leading to a reliable powder production.
Long-term trials by the company have shown there is reduced wear rates of vital spray components due to the improved concentricity. Even better news is that it also improves spray atomisation with the uninterrupted flow path. This results in optimum powder consistency and quality – a perfect outcome!
It’s not an easy task to revolutionise traditional high-pressure spray drying nozzles that have been working adequately in dairy plants for more than 40 years, but Spray Nozzle Engineering has done that and more.
Its Click&Dry spray dry nozzles are the result of close associations with drier operators, powder technologists and managers across the world. One of the outcomes of collaborating with industry specialists is the Concentric Clasp Technology, which is a ‘world first’ in spray nozzle design. Another first is the capacity to produce the finest quality dry powder in state-of-the-art spray nozzles that are so efficient they also improve powder production. It’s a win-win solution for commercial spray dryers
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