Twin Shaft Mixers

A round up of high-performance plant mixers known for their quick cycle times and potential to lower mix designs’ cement dosages thanks to high energy operating mode.



Twin Shaft Mixer models have 4- or 6-yd. output, based on 164 cu. ft. and 245 cu. ft. capacities at 100 lbs. per cu. ft. Each is designed with off-the-shelf components for ease of service and maintenance, and features air purge shaft seals; single drive motor; heavy duty cast steel mixing arms; and, hydraulic discharge door. The high volume, high shear mixing action equates to 60- to 90-second cycle times.Mixer Systems Inc., Pewaukee, Wis., 262/691-3100, 800/75MIXER;



MAO twin shaft mixer series are designed, engineered and manufactured in Italy. Increasing adoption in North America, product engineers note, reflects the series’ flexibility and performance in producing standard to self-consolidating to roller compacted concrete mixes.

Exclusive, patented solutions for transmission and auxiliary devices are the core of Sicoma MAO twin shaft mixers. Other features contributing to their performance are more arms per shaft, arms’ counter flow compulsory action, robust shaft seals with minimal grease consumption, and effective high pressure washing system. The specifications equip each model with powerful compulsory spiral mixing action to throw particles from each side of the vessel towards the center, where they combine; and, jets that force water for complete absorption, allowing cement slurry to uniformly coat aggregates.

MAO series liner plate wear is low, as mixing occurs in the free space above the mixer floor—confining tile replacement primarily to points around the discharge door. Company engineers underscore the mixers’ reliability, consistency, repetitiveness of results, heavy-duty capabilities and ease of maintenance.Sicoma North America Inc., Clearwater, Fla., 727/575-7999, 800/921-7559;



Company is the official North American distributor for Portugal-based Arcen, an ISO 9001-certified manufacturer with concrete mixing equipment installations in 45 countries. Available in 1.3- to 12-yd. capacity models, all with fast discharge capability, the twin shaft mixing system is composed of two synchronized horizontal axes allowing for optimal mixture homogeneity. The Arcen models are suited to ready mixed concrete, high slump precast concrete mix and roller compacted concrete mix production. BMH engineering staff is fully trained for mixer installation, start-up, commissioning and support.BMH Systems, Boucherville, Quebec, 888/793-9340;



The Ocmix RG Twin Shaft mixer and mixer feed system is manufactured by Ocmer, the Italian leader in batch plant equipment. Known for fast mixing action as well as its strong shell and rugged reliability, the model saves on cement for a given quality of concrete, compared to tilt, drum and pan mixers with less vigorous action.

Optional heavy duty, fully galvanized aggregate hopper, cement and water scales—bearing on their own mezzanine floor—become the top of the plant, allowing installation in days with assurance that performance meets expectations. Standard features include efficient two-stage gearboxes; more paddles than most other mixers of equal capacity; extra-hard wearing liner plates; positive shaft seals with low grease usage; and, easy-access single-day shaft and bearing replacement if it is ever needed. Other options include high-pressure washout, reduced-size discharge door and touch-screen alarm and usage monitor. Mixer sizes range from 2 to 10.5 yd., affording hourly compacted concrete output of 80 to 427 yd. — Ocmer North America/Scale-Tron Inc., St. Laurent, Quebec, 514/940-0337, 800/632-7083;



MSO twin shaft mixers are considered an industry benchmark, company engineers note, owing to their reliability, build quality, and high productivity in plants around the world. Models are available with 1- to 12-yd. compacted concrete output capacities. Simem engineers tailor versions for standard and self-consolidating concrete; mass concrete with large aggregate; roller compacted concrete; paste; and, cemented rock backfill. — Simem America Corp., San Antonio, 210/581-5600;



The RT 3000 Twin Shaft Concrete Mixer is available in 4- and 5-yd. capacity models. Product engineers cite such features as compact design, mobile-plant suitability, and ease of transport. They credit a robust, durable design to hexagonal heavy-duty machined shafts; fully tiled mixing chamber; plus, 20-mm-thick chill cast tiles and Rhombus style wear tiles. Two heavy-duty gearboxes are mounted directly onto mixing shafts to prevent excessive loads on bearings. A maintenance-free flexible coupling ensures gearbox synchronization. — Rapid International USA, Commerce City, Colo., 303/853-0068;



Full range of twin shaft mixers, Models DW 1.25 through DW 6.0, have nominal capacities of 2 yd. to 8 yd. and Liebherr-built gearboxes. Equipped with robust, counter-rotating shafts, the mixers are driven by one or two electric motors; gears are mounted directly onto the shafts, saving space. Product engineers cite among mixer performance aspects energy efficiency, long service life and ease of maintenance. High pressure cleaning systems and mixer retrofit packages are available. — Liebherr USA Co./Concrete Technology Division, Newport News, Va., 757/928-8547;



Company engineers cite invention of the twin-shaft batch mixer in 1888, and continuous design and performance upgrades ever since. BHS twin-shaft mixers are the benchmark in concrete mixing technology, they add, as demonstrated in thousands of concrete plant installations across the globe. Optimized tool design and arrangement allow for consistent three-dimensional mixing that ensures full mix homogeneity with very short cycle times. BHS twin-shaft batch mixers are available in 0.7-yd. to 12-yd. sizes, and can be fitted with a wide range of options. — BHS-Sonthofen Inc., Charlotte, N.C., 704/845-1190;