TMXFLOW - Agitator (SKD)
The SKD vertical mixer from TMXFlow is a top-mounted, direct-drive mixer for tanks with a capacity of up to 1,500 litres. It is designed for low-viscosity liquids where complete homogenisation and dispersion are required. Parts in contact with the product are made from AISI 316L stainless steel, with a surface roughness of Ra ≤ 0.8 µm.
SKD vertical mixer: direct drive and high speed
The working unit is driven directly by the motor, without a gearbox. This results in a high rotational speed with moderate torque on the shaft.
This combination determines the scope of application. High speed is required when the task is to distribute a component rapidly throughout a volume or to break it down into fine particles. The torque on the shaft is of secondary importance in this case, as the medium has low viscosity and offers almost no resistance to rotation.
The absence of a gearbox has two practical consequences. The first is compactness: the drive assembly is shorter, and the agitator takes up less space above the tank. The second is that there are fewer parts requiring maintenance, and there is no gearbox oil that could potentially contaminate the product.
How axial flow works and why reflectors are needed
The propeller generates a pronounced axial flow: the fluid is forced downwards through the working element and rises upwards along the walls of the tank, completing the circulation cycle throughout the entire volume.
The problem arises with central placement. The flow then tends to rotate along with the agitator: the contents of the vessel begin to swirl as a whole, a vortex forms at the centre, and there is virtually no exchange between the layers. At this point, the mixing merely appears to be vigorous.
The manufacturer suggests two ways to achieve this. The first is a central mounting with baffles on the walls of the vessel: these interrupt the rotational movement and convert it into axial movement. The second is to offset the agitator’s axis from the centre, which achieves the same effect without the need for baffles.
The method of installation is therefore determined by the geometry of the tank, and is agreed upon at the time of ordering, rather than during installation.
SKD Vertical Mixer: Design and Materials
| Parameter | Value |
|---|---|
| Type | vertical, top-mounted, direct drive |
| Capacity | up to 1,500 litres |
| Viscosity of the medium | low |
| Details regarding the product | AISI 316L |
| Surface roughness | Ra ≤ 0.8 µm (standard) |
| Propeller roughness | Ra ≤ 0.5 µm is available |
| Shaft seal | NBR V-ring with retainer |
| Bearing housing | anodised aluminium |
| Working body | propeller; serrated propeller (optional) |
| Drive | electric; pneumatic (optional) |
| Motor | Standard; ATEX on request |
| Sink | CIP-compatible |
Dispersion of powders using a dust-type propeller
A standard propeller creates circulation but does not pulverise. This is not sufficient for feeding dry components: powder poured onto the surface is drawn into the flow but may remain in the form of agglomerates.
The serrated edge of the propeller increases shear directly within the blade zone. As agglomerates pass through this zone, they break up and the material is dispersed into individual particles.
The manufacturer explicitly states that the combination of a serrated impeller with a high-speed motor makes this series suitable for dispersing powders and additives. Therefore, when the task involves introducing a dry component, the type of working element is selected together with the size, rather than separately.
SKD vertical mixer and CIP washer
The design is fully compatible with on-site washing. This is ensured by the material of the parts in contact with the product, the standardised surface roughness and the geometry, which has no dead zones.
Surface roughness is of direct hygienic importance here. On a highly rough surface, product residues become trapped in micro-irregularities and are not removed by the flow of the cleaning solution. The standard limit for the series is Ra ≤ 0.8 µm, whilst for the propeller the permissible value is Ra ≤ 0.5 µm, as it is constantly immersed in the product.
The shaft seal consists of an NBR V-ring with a retainer; the bearing housing is made of anodised aluminium. Both components are designed to withstand regular contact with cleaning solutions.
What products is the SKD vertical mixer designed for?
The manufacturer lists five areas, each with specific products.
The dairy sector — milk and cream-based products. Food production — syrups and sauces. Cosmetics — creams, gels and emulsions. Pharmaceuticals — suspensions and ready-made formulations. Brewing — fermented liquids and additives.
What these applications have in common is a low-viscosity medium and the need for rapid, complete homogenisation of a small batch. For viscous products, a direct-drive propeller configuration is not suitable: greater torque is required at the shaft, which necessitates a design incorporating a gearbox.
Selection and service from Steiner Ukraine
When selecting a mixer, the task determines the choice, not the power. The volume and geometry of the vessel, the viscosity of the product at operating temperature, and the desired outcome — whether to homogenise, dissolve, disperse or maintain in suspension — together determine the type of drive, the working element and the shaft length.
We clarify these conditions, as well as the installation method – whether using reflectors or with an offset axis – the CIP parameters, the explosion hazard classification of the area, and the availability of compressed air on site. Based on this, we determine the configuration. Next come supply, service and spare parts. Steiner Ukraine has been operating in the industrial equipment market since 2006.
Other models from this manufacturer: SKDS mixer and portable SKP mixer. The remaining items can be found in the section pumping and mixing systems and in the catalogue pumps for the food industry.
