Düsen-Schlick GmbH

Patented ABC technology specifically for pharmaceutical and food production

During coating, conventional flat-spray caps gradually accumulate more and more product particles due to the quantity of dust that is circulating. This not only impairs the spray behaviour, but leads to the nozzle becoming clogged. This is also referred to as ‘beard formation’, or bearding.

The Schlick ‘Anti-Bearding Cap’ (ABC) was developed to counteract this bearding. Turbulence around the air cap and the nozzle opening is minimised, meaning these no longer become clogged and that interruptions to the process to clean the nozzle can be almost completely avoided.

To enable up and downscaling across the entire production process, the Schlick ABC range was developed for various flow rates, and covers drum sizes from 8.5” to 24” and above.

The spray has a constant and homogeneous liquid distribution with very fine, uniform and reproducible droplet size distribution at the same time, and is characterised by a uniform ellipse, which is achieved via the balance between the pressures – the forces of the atomising air and the pattern air.

The ABC technology was designed specifically for coating processes in the pharmaceutical and food sectors but, with further development, it was also possible to adapt it for a wide range of other industrial production requirements. The resulting PRO ABC nozzle is used for moistening, coating, gluing and wetting. A pneumatic on/off control with a cleaning needle is fitted as standard on the Pro ABC nozzle, as is a single attachment for pattern air (PA) and atomising air (AA).

Insertion pipes, nozzle heads and Multispray

Schlick insertion pipes and nozzle heads:
Insertion pipes are available in a wide range of designs and are manufactured or adapted according to the individual requirements of the customer for the desired application. The category is divided into insertion pipes for pressure nozzles and insertion pipes for two-substance nozzles.

The insertion pipes for pressure nozzles can be fitted with any pressure nozzle (full-cone, hollow-cone, flat-spray, smooth-jet nozzles) or even entire nozzle heads depending on requirements and applications. The flow rates and droplet sizes are dependent on the existing difference in liquid pressure.

Insertion tubes for two-substance nozzles are also available in a wide range of designs and various two-substance nozzle models to suit any relevant applications. The droplet size can be individually adjusted according to the propellant/liquid ratio.

Nozzle heads are often used to evenly cover very large surfaces with liquid. Because the liquid quantity is divided between several nozzles through small holes, very fine droplets can be achieved with the maximum air flow.

The heads can be combined with various types of nozzle (full-cone, hollow-cone) and are easily interchangeable. The diverse mounting options mean a wide variety of sprays can be achieved with variable liquid flow rates.

Schlick Multispray:
Schlick Multispray can be used with all current atomisation technologies for two-substance nozzle (flat-spray design and internal/external mixing) and pressure nozzle (hollow-cone nozzles, full-cone nozzles, flat-spray nozzles and smooth-jet nozzles) applications.

Various possible combinations of nozzle caps and the associated liquid insert plus needle make it possible to implement all current atomisation technologies for two-substance nozzle applications.

Furthermore, the Schlick Multispray can also be used as a pneumatically controlled pressure nozzle using the Multispray adapter, without any dripping. Downtimes due to the time-consuming exchange of entire nozzle units are all but eliminated thanks to extremely straightforward modification.

Reproducible solutions for a wide range of requirements

Pressure nozzles – also referred to as single-substance nozzles – use pressure energy to atomise the liquid supplied. There is usually no need for any additional compressed air or steam.

Pressure nozzles are used in a wide range of applications and categorised as follows by Schlick:

– Full-cone nozzles
– Hollow-cone nozzles
– Carbide nozzles
– Flat-spray nozzles
– Smooth-jet nozzles
– Mixing nozzles
– Laval nozzles
– Cleaning nozzles

All kinds of sprays and droplet sizes are possible, depending on the type of nozzle and process parameters concerned. All the relevant conditions and constraints must be taken into account in advance during planning.

Anti-bearding to the highest standard

The Professional Coating Arm (PCA) was specially developed for coating applications and is included with the patented ABC Technology® as standard. This counteracts bearding, meaning that interruptions to the process to clean the nozzle can be almost completely avoided.

The PCA is supplied via individually adapted attachments for control air, atomising air, pattern air and liquid (with flow and return) and functions as a supply unit for all nozzles, as no further hoses or connectors are required. This keeps dirty corners and installation work to a minimum. Fully homogeneous operation of up to eight nozzles is possible with the PCA,

and its sophisticated construction drastically reduces maintenance and set-up times. This is because no special tools are required to install or de-install the supply unit – only two screw fittings need to be loosened. Errors in nozzle spacings arising during installation are also ruled out thanks to the clearly defined dimensions of the individual blocks. The individual nozzles are fixed using two screws only. Each individual nozzle consists of just seven individual pieces plus O-rings.

The Schlick Professional Coating Arm is equipped with a customised attachment mechanism, enabling PCA technology to be operated in almost any system.

Cost-effectiveness and functional design

Schlick two-substance nozzles – also known as pneumatic atomisers – use a second medium (compressed air, gas or steam) to supply energy for atomisation. This results in very fine atomisation even in the case of highly viscous liquids or suspensions.

Depending on its viscosity, density and surface tension, the liquid that is being atomised can be supplied using suction, a downward slope or pressure. Within certain limits, some two-substance nozzles can also act as injectors. Schlick’s product range encompasses both external- and internal-mixing two-substance nozzles.

Schlick three- and four-substance nozzles are designed according to individual customer specifications and enable very fine atomisation of several liquids at the same time with one nozzle and only one atomisation medium (air, gas or steam). Intensive mixing of all the media takes place simultaneously when leaving the nozzle opening. It is also possible to charge a channel with air, gas or steam and thereby create a larger exchange surface between atomisation medium and liquid. There is no risk of reactions between the various liquids inside the nozzle, as the nozzle design means the media only meet at the nozzle outlet.