Grain Conveying: Pneumatic or Mechanical?

Expert advice: KLN & Heumann GmbH · Updated: 27.08.2026

In a nutshell: Mechanical conveyors such as augers, chain conveyors and bucket elevators are the energy-saving choice for fixed conveying routes with high continuous throughput, for example at central silo plants. Pneumatic pressure and suction systems score wherever flexibility counts: in awkward older buildings, at changing work sites and when emptying stores completely. Many farms do best with a combination of the two.

Whether the grain travels through pipes in an air stream or moves on augers, chains and bucket elevators determines construction costs, energy demand and ease of work for many years. Both principles have clear strengths – the right choice depends less on the type of crop than on conveying route, throughput and farm structure. This guide sets the two systems side by side and shows which solution suits which type of farm.

Two principles, one goal: moving grain safely

Pneumatic conveying: pressure, suction or both

In pressure conveying, a high-pressure blower generates a powerful air stream. An injector or a rotary valve feeds the grain into the line, where it is carried through smooth pipes to the discharge point – horizontally, vertically and around obstacles. Diverter valves distribute the flow to several destinations as required, for example along an entire row of silos.

Suction conveying works the other way round: a vacuum picks the grain up via suction nozzle and hose directly from the floor, from the flat store or from the trailer. Suction-pressure blowers combine both methods in one machine – the grain is drawn in, separated from the conveying air in the cyclone and transferred to the pressure side via a rotary valve. According to the manufacturer, high-performance models achieve up to 120 tonnes per hour. The category Pneumatic Conveyors provides an overview of blowers, valves and pipe systems.

Mechanical conveying: auger, chain, bucket elevator and belt

Mechanical systems move the grain positively with moving components. Tube augers work at any angle from horizontal to vertical and handle up to 90 tonnes per hour. Chain conveyors transport horizontally over lengths of up to 50 metres at up to 120 tonnes per hour; angled versions cope with inclines of up to 45 degrees. Bucket elevators lift the crop vertically to heights of up to 25 metres, and belt conveyors move it particularly gently at 60 to 80 tonnes per hour over distances of up to 100 metres. The individual designs are presented in detail in the category Mechanical Conveyors.

Conveying route and installation: where is the difference?

The pneumatic system needs almost nothing in structural terms – only space for the pipeline. The blower stands at ground level, remains easily accessible and can be moved elsewhere or put under cover outside the season. This makes the equipment particularly suitable for older buildings, low store heights and winding routes where a straight conveyor line could not be installed at all. A single blower can fill and empty several silos via diverters.

Mechanical installations, by contrast, follow clearly defined axes: intake pit, angled or chain conveyor, bucket elevator and a conveyor run above the silo row. Those planning a new central plant thus gain a high-throughput backbone that, thanks to its modular design, is easy to extend when further silos are added. Fitting such lines into existing buildings at a later date, however, is more involved than laying a pipeline.

Capacity, energy and wear compared

Both system worlds achieve conveying capacities that keep pace with modern combine harvesters and continuous-flow dryers. The differences lie in the detail:

Criterion	Pneumatic conveying	Mechanical conveying
Principle	Air stream carries the grain through pipes (pressure, suction or combined)	Auger, chain, buckets or belt move the grain directly
Conveying route	Freely routable, even around corners and obstacles; vertical and horizontal in one line	Fixed axes; horizontal up to approx. 50 m per run, vertical up to approx. 25 m with an elevator
Capacity range (manufacturer figures)	Mobile suction-pressure systems up to approx. 120 t/h	Depending on design approx. 20 to 120 t/h (belts 60–80 t/h, augers up to 90 t/h)
Residual emptying	Self-cleaning, no grain remains in the pipe system	Residual quantities possible in corners and troughs, self-emptying designs available
Energy demand	Higher, as the air must also be driven as the transport medium	Comparatively low, especially with belt and chain conveyors
Typical wear points	Pipe bends, rotary valves, blowers	Chains, buckets, bearings, auger flights
Mobility	Mobile units, including tractor-driven models without a mains connection	Stationary, but modularly extendable

In terms of energy demand, mechanics has the edge by principle: it moves only the grain, not large volumes of air as well. Belt and bucket systems are regarded as particularly economical for continuous operation. Pneumatics pays for its freedom of pipe routing with more drive power – but in return does without moving parts along the entire route.

Wear is also distributed differently. In the pipeline it is concentrated at a few points such as bends and valves, which can be replaced in a planned manner. With mechanical conveyors, chains, bearings and buckets age throughout the entire installation. Both worlds are gentle on the grain if design and speed are right – smooth pipes and gently running belts avoid breakage in equal measure. Suitable wear and spare parts for both system worlds can be quickly narrowed down via the spare parts finder.

Flexibility in everyday use: mobile, combinable, completely clean

Pneumatics plays its greatest strength away from fixed conveying routes. Mobile suction-pressure blowers with tractor drive work without a mains connection and load grain directly at the field edge into trailers or lorries. The same equipment unloads lorries, wagons or ships and, after mechanical emptying, vacuums the last residual quantities out of silos and flat stores – a point that can be decisive for store hygiene, seed purity and switching between lots.

Mechanical installations counter with reliability in continuous operation: once planned, pit, elevator and chain run season after season with little operator effort. For sensitive seed there are self-emptying bucket elevators and gently running belt conveyors that carry the crop to the discharge point almost without agitation.

Decision guide: which system suits which farm?

Arable farm with a central silo plant: Mechanics as the backbone – intake pit, bucket elevator and chain conveyor above the silo row deliver high continuous throughput at low energy demand and grow modularly.
Farm with older buildings or a flat store: Pneumatics – only a pipeline is needed, the blower stands at ground level, major conversions are unnecessary. Ideal for low building heights and convoluted routes.
Livestock farm with hopper silos: Both routes lead to the goal. A blower system with rotary valves serves several silos via one line; alternatively, angled conveyors and an elevator handle hopper filling and emptying.
Seed production and multiplication business: Self-cleaning takes priority so that lots are not mixed – self-emptying bucket elevators and belt conveyors, or a pneumatic system that leaves no grain in the line after conveying.
Contract work and field-edge loading: Mobile suction-pressure blowers with tractor drive that work independently of the mains at changing locations.

Conclusion: define the conveying task first, then choose the equipment

The question is rarely pneumatic or mechanical, but rather: where does which task lie? Proceed as follows:

Map out the conveying routes: record distances, heights, corners and future extensions honestly.
Define the throughput: the installation must match the intake capacity at harvest, not the average day.
Estimate the operating hours: with many full-load hours on fixed routes, the lower energy demand of mechanics pays off; with changing tasks, the flexibility of pneumatics.
Clarify the hygiene requirements: seed, organic lots and feed quality argue for self-cleaning solutions or pneumatic residual emptying as a supplement.

In practice, the combination often proves its worth: a mechanical main axis for the bulk flow, supplemented by a pneumatic system for loading, special routes and complete emptying. Those who use both principles in a targeted way move their grain quickly, gently and at predictable cost.

Frequently asked questions

Which conveying system uses less energy?

Mechanical conveyors such as belt, chain and bucket systems generally work with lower energy demand because they move only the grain. Pneumatic systems must also drive the conveying air and therefore need more power – but in return offer freely routable conveying paths without moving parts in the line.

Why does residual grain remain after mechanical silo emptying?

Mechanical discharge systems often cannot fully reach the corners and edge areas of large silos and flat stores, so residual quantities are left behind and can cause spoilage or hygiene problems. A pneumatic suction system with a movable suction nozzle picks up these residues and enables practically complete emptying.

Can I combine pneumatic and mechanical conveying?

Yes, in practice this is actually the most common approach: a mechanical main axis of pit, elevator and chain conveyor handles the bulk flow, while a pneumatic system covers flexible tasks such as field-edge loading, lorry unloading and the residual emptying of silos. The two worlds can be connected via shared transfer points.

What capacity do pneumatic grain conveyors achieve?

According to manufacturer figures, high-performance mobile suction-pressure systems achieve up to around 120 tonnes per hour and thus keep pace even with high intake rates at harvest. Actual capacity depends on the conveying route, line length, height difference and the crop.