Simpson Multi-Mull® Continuous Mixer

Multi-Mull for Process Applications 
While conventional mixing is usually adequate for the blending of dry solids, only more intensive forms of mixing can produce total uniformity in a mix of materials having disproportionate mass, particle size, liquidity, viscosity or density. Simpson is here to assist you in reviewing wetted solids mixing options.

In medium to large-sized continuous processing systems or mixing applications. The Simpson Multi-Mull® has been carefully designed to achieve maximum performance, consistency, and energy efficiency in these types of applications. Simpson Multi-Mulls have been successfully applied to a very large number of applications in the chemical processing industries including lead acid battery paste, briquetting of a variety of materials, catalysts, chocolate, ferrites, fertilizers, lead pencil graphites, mineral ores, pharmaceuticals, pigments, powdered metals, and welding rod flux.

With over 600 installations across the globe, Simpson has brought confidence, reliability, and increased productivity to several manufacturing sectors.

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Delivers up to 50% more hourly production than two batch mixers of equivalent diameter.


Medium-speed, high-intensity, muller-type mixer for continuous operation.

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Medium-very large size process preparation systems seeking consistently high volumes and maximum efficiency.


– Continuous mixing with back blending
– Maximum energy efficiency
– Controlled retention for consistency

Continuous Mulling - The Ideal Situation

The Simpson Multi-Mull is a medium speed, high intensity continuous mixer that is like no other. The synchronized dual muller and overlapping dual plow design enables sand and additives to be circulated and recirculated in a figure 8 movement within the Multi-Mull where they receive maximum exposure to mulling action before final discharge through a modulating door.

The Multi-Mull gives you an advantage over your competitors by:

  • Delivering a continuous supply of material, on-demand
  • Consistently providing discharged material of superior quality and uniformity
  • Producing high quality material at a lower cost than any other solution
  • Protecting margins through lower energy consumption
  • Wasting no operating time on batching, charging, discharging, pre-mull dispersion
  • Requiring far fewer system components Example: (1) Multi-Mull = 23 components vs. (2) Small Batch Mullers = 85 components
  • Lowering installation cost and reducing maintenance
  • Reducing profit-robbing downtime

Mixing vs Mulling

A concise definition of mulling would read “an intensive and controlled mixing process.” Mulling action is a combination of controlled pressure and agitation, to achieve a high degree of uniformity in the preparation of two or more dry/solid or wetted/solid materials rather than agitation alone.


A mixer for combining solid materials usually operates with a stirring or beating action effected by blades, paddles, arms, or flighting. The normal action of this type of mixer though adequate for simple blending tasks, is not suitable where tempering action, strict uniformity or the intimate blending of a relatively small amount of material into a large mass, is desirable.


The muller is used where materials of disproportionate mass, density, viscosity or particle size must be evenly dispersed to form a homogenous mass… without segregation/or where a small amount of one or more materials must coats each grain of a larger mass.

Efficiency Makes You More Competitive

For high-volume, high-quality, cost-effective casting production, the Simpson Multi-Mull is the best solution. This technology produces larger volumes of materials at a lower cost of installation and operation than any other mixer in the world.

The Mix Muller and Multi-Mull operate on the same principles.

Energy Efficiency Utilizing 3 Forms of Energy:

  • Electric by Motor
  • Mechanical by Loading Spring
  • Gravitational by Weight of Wheel
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More Depth, How Does Mulling Make More Homogenized Product?

Mulling is a unique combination of a kneading, smearing and spatulating action that intensively homogenizes difficult to mix materials. Vertically oriented wheels mounted to a crosshead rotate freely around a center axis to impart the mulling action to the materials on the mixer floor. A combination of plows moves the material into the path of the mullers and assists in the blending operation. Discharge is accomplished via a bottom door in the mixer pan.

Simpson first introduced the concept of the Multi-Mull in the 1950s.

The current Simpson Multi-Mulls are the result of over 70 years of continuous research and practical field experience in material preparation systems. Over 600 facilities around the world have relied on the Simpson Multi-Mull to cost effectively and consistently prepare of their materials.