Twin Shaft Mixer

A heavy-duty twin shaft mixer for ready-mix, precast and RCC, built for short cycles and repeatable batches. Six sizes from 1.0 to 6.0 m³ of compacted concrete.

The Vanguard twin shaft mixer sits at the center of a batching plant. Two counter-rotating shafts carry paddles that lift, fold and shear the batch at the same time, so aggregate, cement and water reach an even mix in a fraction of the time a gravity drum needs. That intensity is what makes it the usual choice for stiff, low-slump and fiber-reinforced mixes. Six sizes are available, from 1,500 litres dry input and 1,000 litres compacted output up to 9,000 litres dry input and 6,000 litres compacted output.

Key benefits

Six sizes from 1.0 to 6.0 m³ compacted output, matched to plant throughput
Short mixing cycles, suited to high-strength, low-slump, RCC and fiber-reinforced mixes
Ni-Hard cast liners and paddle tips on every surface the batch touches
Central automatic lubrication protecting the shaft end seals from dust
Hydraulic discharge gate with a manual emergency override

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Engineered for short cycles and repeatable batches

From the shaft seals to the discharge gate, the Vanguard twin shaft mixer is built around the parts that wear. Here is how it works, which sizes are available and where it fits.

How the twin shaft mixer works

Two shafts turn towards each other inside a W-shaped trough. The paddles on each shaft throw material into the path of the other, so the batch is lifted, dropped and sheared at once rather than simply tumbled. The overlapping zone in the middle of the trough is where most of the work happens, which is why the cycle is short and why one batch comes out like the last. Water and admixtures are sprayed across the full width of the trough, so they are already distributed when mixing starts.

Ni-Hard Wear Protection

Every surface the batch touches is protected. The trough liners, the paddle tips and the shaft covers are Ni-Hard casting, bolted in place so worn sections can be swapped instead of rebuilding the trough. Wear rate depends on what you are mixing, so a plant running crushed basalt will change liners sooner than one running river gravel.

Rapid Mixing Cycle

Paddle geometry and spacing along each shaft are set so the whole batch passes through the overlap zone several times per revolution. The practical effect is a shorter wet mixing time for the same homogeneity, which raises the number of batches the plant turns out per hour. The exact cycle depends on the mix design and is set during commissioning.

Automated Lubrication

The shaft end seals are the part of a twin shaft mixer that fails first when neglected, because cement dust works its way in from both sides. A centralized greasing system feeds every seal and bearing on a timer, keeping a grease barrier against dust rather than relying on someone remembering a weekly round.

Hydraulic Discharge Gate

A hydraulic cylinder opens the gate, so the operator can crack it part way and meter the discharge into a truck or a skip instead of dropping the whole batch at once. A manual override opens the gate if hydraulic pressure is lost, so a batch is never trapped in the trough.

Twin shaft mixer models

Six sizes, given as dry input and compacted output:

1,500 / 1,000 L, 1.0 m³ output
3,000 / 2,000 L, 2.0 m³ output
4,500 / 3,000 L, 3.0 m³ output
6,000 / 4,000 L, 4.0 m³ output
7,500 / 5,000 L, 5.0 m³ output
9,000 / 6,000 L, 6.0 m³ output

Dry input is the loose volume the trough holds. Compacted output is the finished concrete that comes out of it. Sizing a plant on dry input alone is the most common reason a mixer turns out smaller than expected. Motor rating and dimensions depend on the configuration and come with the quotation.

Options

An automatic washing unit cleans the trough at the end of the shift from a single button. Rotating heads with three nozzles each run at up to 130 bar and 70 litres per minute, taking residual concrete off before it sets, and the unit comes with two or four heads depending on mixer size. A safety interlock can also be fitted, cutting power to the mixer before the inspection hatch can be opened, so nobody works inside a machine that can still start.

Where a twin shaft mixer makes sense

A twin shaft mixer is the default for ready-mix plants that need consistent output at volume, and for precast and pipe plants running stiff, low-water mixes a gravity drum cannot handle. It also suits RCC and fiber-reinforced work, where even distribution matters more than speed. If your plant runs a simple, low-volume mix, a planetary or pan mixer may be the cheaper answer, and we build those too. Tell us your mix design and the batches per hour you need, and we will size the mixer.