VerderMix – dynamic indirect-action mixers

The VerderMix gearbox mixer is a low-speed version of a dynamic mixer, featuring a gearbox between the electric motor and the shaft. The speed is reduced to 15–350 rpm, which ensures gentle mixing in applications where a high-speed mixer would destroy the product’s structure. Manufacturer: Verder, VerderMix range. Three models, differing by gearbox type: VFG, VKG and VWM.

When to use a gearbox, and when to use a direct drive

The difference between the two versions of the VerderMix dynamic mixers lies in their speed, and it is a tenfold difference.

Direct-drive mixer Operates at 750–3,000 rpm. This is suitable for intensive mixing, dissolution and working with low-viscosity media.

A mixer with a gearbox operates at 15–350 rpm. Low speeds are required where caution is more important than intensity: flocculation, where a rapid flow breaks up newly formed flocs; viscous and dense media, where high speeds cause cavitation rather than mass movement; and products with a fragile structure.

The second practical difference is the shaft length. The VFG model can accommodate shafts up to 3,000 mm, compared with 1,700–2,500 mm in direct-drive versions. For deep tanks, this is often a decisive factor.

The VFG, VKG and VWM models

VFG — parallel-shaft gearbox. The widest speed range in the range, 15–350 rpm, and the longest shaft — up to 3,000 mm.

VKG — spiral-bevel gearbox. Speed: 15–300 rpm, shaft length up to 2,000 mm.

VWM — worm gearbox. The same 15–300 rpm and a shaft length of up to 2,000 mm; it differs from the VKG in its layout and transmission characteristics.

In the VKG and VWM models, the paddle agitators are detachable — the shaft passes through the mounting hole without the agitator, whilst the agitator is fitted inside the vessel.

Technical characteristics

PB2, PB3 and PB4 blade agitators

Three types of blade agitators are available for all three models: PB2, PB3 and PB4. In the VKG and VWM models, they are removable.

The manufacturer does not publish a separate description of each type in the public domain; the choice is determined by the viscosity of the medium, the geometry of the vessel and the required flow characteristics. The general design principle of the VerderMix is to prevent stagnant zones and sediment from forming at the bottom and sides of the tank.

Seals and options

• a sealed lamp with a face seal, a lip seal or a gland packing — for all three models
• Bearing torch — for VKG and VWM
• chemically resistant coating — for all three models
• fixed or mobile racks to the customer’s specifications

What is custom-made

The manufacturer does not list these items in its public catalogue — they are specified at the time of selection:

• gearbox ratio for the required operating speed
• electric motor power
• the diameter of the paddle mixer and the number of tiers
• materials used for wetted parts
• volume, depth and geometry of the tank, method of installation

Where are VerderMix low-speed mixers used?

According to the manufacturer:

• flocculation and coagulation in water treatment
• wastewater treatment
• mixing of viscous media
• homogenisation of solids in a liquid
• reactor vessels

Sectors: water treatment and drainage, the food industry, the chemical industry, and the pharmaceutical industry.

For mixing directly in the flow, without a container, the following are used VerderMix - Static mixer.

Selection and service from Steiner Ukraine

A low-speed mixer is selected based on the product: firstly, how gentle the mixing needs to be and what speeds are acceptable for this; next, the depth of the vessel, which determines the shaft length; and only then the model and type of gearbox. We coordinate the configuration with the manufacturer and ensure service and spare parts. Steiner Ukraine has been operating in the industrial equipment market since 2006.