The optimum course of for changing liquid merchandise into bulk supplies is determined by the specified properties of the ultimate particles and the precise utility. Right here, Glatt is well-placed to advise on the professionals and cons of every methodology because of her expertise and experience in designing fluid mattress techniques for particular person wants and finish merchandise.
The fluid drying course of permits the ensuing product to be extra simply managed and saved at ambient temperatures. Furthermore, the completed product shouldn’t be solely extra secure than liquid uncooked supplies, but in addition drastically decreased weight and quantity, thus decreasing transportation and storage prices.
To shortly and successfully dry liquids, spraying them in a stream of scorching air (spray drying) is a price efficient methodology that has been used for many years to course of massive bulk merchandise similar to milk powder. Spray drying can be splendid for merchandise with low solids content material as comparatively excessive temperatures can be utilized. Attributable to the truth that lots of water evaporates, the cooling impact and brief processing time assist scale back heat-related injury. Nevertheless, the fantastic particles generated can create dusting issues, particularly when enzymes or different proteins are current. Since they’re typically robust allergens and finely distributed within the type of mud, additional processing is required.
Focused options for a lot of purposes
Fluidized mattress spray granulation takes the core idea of spray drying to an entire new stage, with focused options for a variety of fabric techniques, purposes and market segments. In comparison with spray drying, the fluidized mattress course of permits desired product properties, together with construction and dimension, to be tuned in a focused method. That is made attainable by the mix of two course of steps: convection drying or solidification and particle formation, with particle sizes from 200 μm to 2 mm simply achievable. Against this, spray drying solely yields particles with a diameter of about 10 μm–300 μm. The dispersed droplet dries up because it descends from the spray tower, which signifies that its dimension is constrained by the peak of the tower, so vital particle progress can solely be achieved with an extra agglomeration step.
Droplet formation and movie drying
In contrast to spray drying, the place a liquid containing solids is atomized in an empty course of chamber, in spray granulation, it’s dispersed in a mattress of fluidized particles. The solvent—often water or an natural materials—evaporates quickly, in order that particle progress happens by droplet formation and membrane drying (Fig. 1). Throughout this course of, referred to as granulation drying or accumulating granulation, new kernels are continually created.
They are often produced in two methods: by abrasion and/or the truth that some small droplets lose suspended particles within the fluidized mattress and dry instantly. Externally, the granulation nuclei can include fantastic particles or floor grains derived from the grinding sieve circuit. Right here, the outsized and small particles are separated, crushed by the pin mill and returned to the method. Each direct nucleation (spray drying) – the so-called overspray – and oblique nucleation management the exponential progress of particles through the course of, and kind the idea for secure and steady granulation. (picture 2)
Create customized particles
With their multi-chamber design, steady fluidized mattress spray granulation techniques (Fig. 3) enable a number of course of steps to be mixed. Theoretically, the oblong fluid mattress system might be inbuilt any dimension, in order that totally different product properties might be tuned in successive working rooms to create custom-made particles.
On many tasks, Glatt course of engineers have been capable of considerably scale back particle dimension and generate soluble powdery particles from answer similar to hydrolyzed proteins utilizing a liquid mattress with a preliminary spray drying step. These had been then agglomerated and reached a better density as a consequence of collisions and steady hydration. Lastly, these particles dissolve in water sooner as a result of they sink extra shortly than spray-dried-only merchandise. In addition to solubility, this course of reduces package deal sizes as a consequence of elevated bulk density, leading to financial savings in storage and transportation – one other step in the direction of sustainability. (Fig. 4)
closed circuit surroundings
Multi-chamber fluidized mattress techniques can spray from above or from under. Intermediate drying and cooling steps are additionally attainable, and post-cooling might be executed in the identical unit. Fluidized mattress spray granulation techniques that deal with natural solvents or oxidation delicate merchandise can be simply built-in right into a closed circuit surroundings.
The principle distinction between spray drying and fluidized spray granulation is the particle dimension and morphology: in spray drying, the particles dry from the surface in; Whereas in fluidized mattress spray granulation, the particles dry from the within out.
The stream of scorching air during which the droplets dry creates a stable outer shell, which boosts the focus of the dissolved part, but the inside core of the particle stays liquid. Because the temperature rises, this moisture evaporates and diffuses, inflicting hole pellets. Gaps happen within the molecules if moisture escapes all of a sudden. Moreover, relying on the drying pace and the focus of solids within the liquid, the particles could rupture, making them unsuitable for encapsulated energetic supplies. (Fig. 5)
Defending energetic elements
Spray granulation additionally produces compact spherical balls with an onion-shaped construction by build up the product layer by layer. This permits versatile and sophisticated product design during which particles might be composed of various stable layers, with cores loaded and plated (Fig. 6), giving meals producers the chance to create purposeful value-added merchandise. Furthermore, the particles of the pre-spray granules might be coated with the identical system to guard the energetic ingredient or masks disagreeable tastes and odors.
Spray granules differ from dried merchandise in that particle dimension, form, and construction might be modified based on the specified utility. Fluid mattress spray granulation is really helpful for delicate feeders, for instance, and for changing emulsions and oils into compact particles. As a result of they’ve a smaller floor space in comparison with spray-dried merchandise, these vitamins are higher protected towards oxidation and have a decrease drying temperature.
Glatt intently displays every fluid venture, from fee to set up. Along with creating custom-made and purposeful product options, the corporate additionally provides venture start-up, improvement, and turnkey manufacturing unit handover.