Grain Sieving and Cleaning Machine Electric Motors

A grain sieving machine motor runs the machines that strip stones, stalks, dust, broken kernels and foreign seeds from pulses, rice or bulgur before packing: the eccentric of the pre-cleaning sieve, the fan and reciprocating drive of the destoner, the trieur cylinder, the grading sifter and the aspiration fan. This page is not about wheat cleaning ahead of a flour mill; it covers the pre-packing cleaning line for products that go straight to consumers, such as lentils, chickpeas, beans, rice and bulgur. Maker catalogues give single motors of 0.37–7.5 kW on these machines and around 9 kW for combined units.

DRG Motor is a manufacturer, supplier and seller of electric motors. We do not sell sieves, separators, destoners, trieurs, optical sorters, compressors, gearboxes or inverters. Our share of a cleaning line is the three-phase induction motor inside each of these machines; models are on Buy Electric Motors Online.

What does each machine do in a pre-packing cleaning line?

In a pulse or rice packing plant the product passes through a pre-cleaning sieve, aspiration, destoner, trieur, grading sifter and optical sorter in turn, and then to the packing machine. Each machine sorts by a different property: size, weight, length, colour.

Pre-cleaning sieve and separator

An inclined sieve box swings on an eccentric shaft; coarse foreign matter stays on top, fine dust and sand drop through. In one catalogue’s machine with a 1500×1000 mm screen the eccentric motor is 3 kW, the product distributor 0.75 kW and the waste screw 0.55 kW. The eccentric is driven by a standard motor and belt. In some separators the sieve box is shaken by two small motors instead.

Destoner

Stone and kernel may be the same size; the difference is density. In a destoner an inclined deck is fluidised by air from below and oscillated; heavy stones walk uphill, light kernels slide down. Two drive types exist: one maker’s pressure machine shakes the deck with a 1.1 kW balanced eccentric and gets its air from a 7.5 kW fan; another’s suction machine shakes the deck with two vibrating motors, with no belts or eccentric. The second type runs on vibration motors, which sit in a separate product group of ours: vibration motors.

Trieur and grading sifter

A trieur sorts kernels by length as an indented cylinder turns slowly: broken rice and foreign seeds in lentils come out here. The motor usually turns the cylinder through a gearbox. The grading sifter splits product into size classes; whether packed lentils or chickpeas look uniform depends on this machine.

Optical sorter

Cameras see colour differences and air valves blow faulty kernels aside. In one catalogue the machine’s own consumption is 2–6.7 kW; the big motor is in the screw compressor feeding the valves with compressed air. The optical sorter itself is not our subject; for the compressor motor see our Compressor Motors category.

How many kW is a sieving and cleaning machine motor? Catalogue values

A) Motor ratings published by makers of pre-packing sieving, destoning, trieur and sorting machines:

In this machine group single motors run roughly 0.37–7.5 kW; the combined separator-aspirator totals 9.24 kW across four motors. The optical sorter rows show machine consumption and a separate compressor, not one drive motor. Capacity in t/h and product type change the choice; the same machine handles a different tonnage of rice or lentils than of wheat.

B) Where DRG fits: every eccentric, fan, screw and trieur rating in the table, 0.37 kW up to 7.5 kW, finds a 4-pole match in frames 71 to 132M, and 2- or 6-pole versions exist where a drawing asks for them. Vibration motors on suction destoners and shaken separators are supplied on quotation, not through the shop.

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Example: scaling a trieur and matching line motors

In one maker’s trieur series the main cylinder motor changes with capacity as follows:

Capacity rises 16-fold while motor power rises about 11-fold; installed power per tonne drops on the large machine. A small trieur’s motor therefore cannot be scaled down from a large model; each model is judged on its own data sheet.

DRG match for pre-cleaner and destoner

Let us match the catalogue pre-cleaner and pressure destoner motors with 4-pole models from our range (starting current = rated current × Is/In; rated torque: DRG-132M-4, 49.1 Nm):

The line’s largest starting current is at the destoner fan. A fan impeller is heavy and slow to accelerate, so it is better brought in before or after the sieve, in sequence rather than together. Fan speed depends on the impeller drawing; the 2-pole equivalent DRG-132S2-2 is also in the range. For starting method see our star-delta tool.

Dust, aspiration and motor position

Motor outside the product-contact area

Dust is the main enemy of a cleaning line. Place each motor clear of the product-contact area, next to the sieve box or low on the frame, and keep its belt guard shut. If the aspiration duct is cut off, dust settles on the motor cowl and the motor runs hot. Our IP55 motors suit a dusty room. If the aspiration fan is a separate unit, see the Fan Motors category for its motor.

Explosive dust and washing

An Ex motor becomes mandatory wherever a filter or silo is zoned for explosive dust, and our standard supply does not include one. Pulses are sometimes washed after sieving; if the washing section needs a stainless-steel washdown motor, that is outside our range; talk to us.

Motors outside our range

Small firms running single-phase sieving machines will not find that motor with us, nor will they find a brake motor, servo or two-speed pole-changing unit in our range. To adjust trieur or sieve speed, a standard motor is fed from an inverter sourced separately.

DRG motors for sieving and cleaning machines

Models matching sieve, fan, screw and trieur ratings (current at 400 V):

Eccentric sieves and fans usually take foot-mounted (B3) motors; trieur and screw gearboxes take flange-mounted (B5 or B14) motors. Before the sieve motor comes off, record its kW and rpm, shaft with key, mounting style and the path of the belts; we confirm suitability together with the machine documentation and promise no fit before seeing the dimensions.

Wheat cleaning in a flour mill is a different flow (tempering, scouring, debranning); for that see Grain Cleaning Machine Electric Motors and the Flour Mill Electric Motors category.

Live price table

Current prices of models matching sieving, destoning and trieur ratings:

DRG MOTOR motors are guaranteed against material and manufacturing defects for 2 years from the delivery date (warranty certificate).

Motors in this power range

• DRG-802-4 – 0.75 kW – 1420 rpm – 80 cast iron
• DRG-90S-4 – 1.1 kW – 1445 rpm – 90S cast iron
• DRG-100L2-4 – 3 kW – 1450 rpm – 100L cast iron
• DRG-132S-4 – 5.5 kW – 1460 rpm – 132S cast iron
• DRG-132M-4 – 7.5 kW – 1460 rpm – 132M cast iron

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Browse the products, ask for a quote: motors for your cleaning line are on Buy Electric Motors Online. Tell us which machine’s motor you are replacing and send its plate via WhatsApp, or give us product type and hourly capacity at +90 (542) 666 11 11.

Frequently asked questions

How many kW is a grain sieving machine motor?

Catalogues show 3 kW on an eccentric pre-cleaning sieve, 3–5.5 kW on a square sifter and 0.37–4 kW on a trieur. The value depends on screen area and capacity.

Is a destoner motor a standard motor or a vibration motor?

Both exist. Eccentric types use a standard motor plus a fan motor; vibrating types use two vibration motors. The machine plate tells you which.

What does the price of a sieving machine motor depend on?

Rating, poles and frame type; figures in the table above are live.

For questions: +90 (542) 666 11 11 · info@drgmotor.com · contact.