Magnum Series

Counter-flow Drum Mixers

The original, high performance counter-flow unitized drum mixer, the Magnum series has set the standard for more than thirty years, in mix quality and durability still out of reach by other manufacturers.

Considered by many as the industry bellwether, the Magnum still sets the industry standard for a unitized drum mixer.

The efficiency and predictability of daily performance of the CMI Magnum series has proven to be valuable to operators of large stationary installations as well as highly mobile paving companies running CMI Super Portable series of asphalt plants.

This is part of the family of counter-flow drum mixers that incorporates the latest in counter-flow technology and is capable of meeting the most stringent air quality regulations, providing improved mix quality and lower cost per ton.

Available as portable drums in capacities from 150 to 500tph and as relocatable and stationary drums in capacities from 300 to 600tph, Magnum drums move virgin aggregates and RAP materials counter to the flow of the exhaust gas inside the drum.

Virgin aggregate is dried and heated by the exhaust gas in front of the burner flame.

The aggregate then moves behind the flame into a mixing chamber that is isolated from the hot gas stream. It is here that the liquid asphalt, additives, fines and RAP materials are added to the mix.

  • Field proven counterflow technology
  • 30% + RAP with low maintenance costs and a single shell design
  • Tuneable performance provided by indexing slingers
  • Longest mixing zone in the industry produces high quality material
  • Super Portables have fast setup and tear down times for high mobility
  • Available in Super Portable, Portable, Relocatable and Stationary configurations


  • Specially designed flight arrangement begins with material intake distribution flights, which feed the aggregate drying flights
  • The unique design of the combustion flights keeps material out of and away from the burner flame, allowing for complete combustion
  • A patented reversible slinger allows simple calibration and varies the effective drying lengh of the drum enabling the most efficient performance
  • The recycle inlet allows the introduction of processed, crushed and reclaimed pavement material

Drying Heating Zone

Unique veiling flighting that allows full utilization of indexing slingers has been refined based on year of experience in counterflow drums and can be tuned to maximise efficiency in all applications.

Combustion Zone

The combustion zone of Magnum drums benefits from flights that hold dried material against the drum shell and allow any airborne VOC’s from the mixing zone to be passed through the intense burner flame, eliminating visible stack emissions.

Mixing Zone

Magnum drums feature the longest mixing section in the industry and are equipped with CMI’s unique “castlelated” flights, resulting in the best mixing of any counterflow drum.

Indexing Slinger

Indexing slingers on all Magnum drums (manual on Super Portable drums) allow the most efficient drying and heating by varying the point at which aggregate veiling begins.

super portable
Super Portables

Magnum Super Portable drums are pre-sloped, allowing for quicker setup and tear down and include full width landing pads.


The optional portable aggregate feed unit with integral scalping screen and slinger conveyor enable fast site setup and relocation with minimal foundations.


Portable, relocatable & stationary arrangements
Specialized transport trailers for reliable roadability in select markets
Chain drive with trunnion drive as standard
Multiple burner options
Numerous dust handling configurations and technologies


  Units 150 225 275 300 400 500 600
Output tph 150 225 275 300 400 500 600
mtph 136 204 250 272 363 454 544
MAIN Drum Diameter ft / ins 5’ 4" 7’ 7’ 7’ 4” 8’ 4” 9’ 5” 10’ 6”
mm 1600 2130 2130 2235 2540 2900 3200
Drum Length ft / ins 33’ 39’ 4” 39’ 4” 44’ 48’ 52’ 56’
mm 10058 12010 12010 13437 14630 15850 17070
DRUM Drive hp 4 x 15 4 x 20 4 x 25 4 x 30 4 x 50 4 x 60 4 x 100
kW 4 x 11 4 x 15 4 x 19 4 x 22 4 x 38 4 x 45 4 x 74
Air Volume
Total ft³ / min 24000 36000 44000 48000 64000 80000 96000
m³ / min 679 1020 1246 1359 1812 2265 2718
Burner Type - Fuel Oil Fuel Oil Fuel Oil Fuel Oil Fuel Oil Fuel Oil Fuel Oil
Capacity x106 BTU / hr 49.3 75.6 96.8 96.8 120 150 200

Find Out More


to download our brochures
Magnum Series Brochure
to download our brochures
Asphalt Plants Brochure

Standard Havens is a registered trademark of CMI Roadbuilding Limited in the United Kingdom, the European Union and Australia.