Though people often identify pugmills as a mixer to add moisture back to dried potter’s clay, there are also many industrial applications for larger pugmills to mix large volumes of material. These pugmills are used to add water into a mixture, mix several dry materials, or to dry large volumes of liquids or sludges.
What Is a Pugmill?
Pugmills are mixers that mix multiple materials into a homogeneous mixture very rapidly. Smaller pugmills are used to recycle and reclaim clay in pottery studios. These pugmills can also be used to de-aerate and add moisture back to the clay to make it usable again. Industrial pugmills are powerful, reliable solutions for continuous mixing processes, particularly those with abrasive aggregates. Pugmills are suitable for producing mineral mixtures for road base, Roller Compacted Concrete, landfill bentonite liners, and for drying sludges with reagents. These pugmills offer higher production rates of 50 to 1000 tons per hour.
What Do Pugmills Do?
Pugmills are used in rock quarries across the US to add water to aggregate to make road base. They are also used on construction sites to make Cement Treated Base, Roller Compacted Concrete, and Flex Base. Pugmills are used in landfills to dry waste sludges by adding drying agents in the mixer so that the dried sludge can be landfilled. Pugmills are also used to stabilize waste dust such as fly ash, bed ash, and cement kiln dust. Newer applications include using pugmills to dry drilling fluids from the oil and gas industries, tunnel boring machines, and liquids from hydro excavation.
How Does a Pugmill Work?
Pugmills generate rapid mixing action using the counter-rotation of the the two mixing shafts as well as the inclined position of the mixing blades resulting in an intense vertical and horizontal mixing motion. High quality consistent continuous mixes can be obtained using accurate dosing and weighing equipment to ensure that the materials entering the pugmill are in the corrector proportions.
The Continuous Pugmill Mixer
The BHS Sonthofen LFK Continuous Mixer or Pugmill is a twin shaft mixer engineered in Germany. The mixing system works with two horizontal mixing shafts equipped with synchronized mixing arms with adjustable paddle tips. The paddle tips accelerate the aggregates being mixed and generate intensive relative movements which create a homogenous mixture in a short 8-10 second retention time.
How the Continuous Pugmill Differs from a Batch Mixer
In a batch mixer, all ingredients are charged into the mixer in a pre-defined sequence, and then mixed, discharged, and the charging process begins again. In a continuous mixer or pugmill, material is constantly entering and exiting the mixer. The materials must enter the mixer in the correct proportions. The mixing results in continuous mixers depend on metering accuracy and metering sequence of the incoming materials. Errors in the timing of the metering cannot be corrected by the mixer. If the aggregate enters the mixer before the water or cement starts flowing, the aggregate will leave the mixer just like it came in. Thompson Rock Mixers’ PLC controls and onsite startup assistance eliminate these errors.
Wide Range of Applications
The BHS LFK mixer has excellent resistance to wear, is easy to maintain, and has outstanding energy efficiency. It is ideal for mixing road base with water, Roller Compacted Concrete (RCC), Cement Treated Base (CTB), flex base, cold mix asphalt, and lime addition for asphalt plants.
Standard Features on every pugmill that set us apart:
- Automatic grease lubrication system for the (4) axial face shaft seals.
- Large clean-out doors in the trough of the mixer allow for easy maintenance access.
- Electromagnetic locking system prevents the top doors from being opened during operation.
- BHS patented worm gear drives and maintenance-free elastic couple eliminate the hassle and expense of timing gears.
- Bolt-on wear plates protect the inlet and discharge end walls from premature wear, and bolt-on cast wear liners for the mixing trough.
Contact us for specifications, pricing, and delivery details on our pugmill systems.