Ribbon, Paddle and Plow Blenders


Blend dry solids, pastes and slurries in 5 to 10 minutes. Versatile, economical and effective when low-energy agitation is required

The MUNSON® Ribbon, Paddle and Plow Blenders feature stationary U-shaped vessels with flat cover sections on top and a discharge valve on the bottom, and a single, horizontally-oriented shaft rotating on external bearings, with radial arms supporting ribbon, paddle or plow agitator elements, each of which offers distinct benefits across a diverse range of applications.

These blenders force agitators through stationary material, which accelerates the dispersion of individual particles into liquids. As a result, they can blend solids with solids, as well as solids with low or high percentages of liquids to produce smooth pastes or slurries.

From sanitary blenders for pharmaceutical and food products on a laboratory, pilot plant or production scale, to robust, super-duty machines for soil reclamation, building materials and oil sludge treatment, MUNSON custom-engineers each Ribbon, Paddle and Plow Blender to deliver maximum performance for your specific application.


Design and Construction

Mixing capacity is approximately 70 to 80% of total vessel volume, providing: 1) ample space for material flow on the upswing side of the agitator, 2) complete agitator contact with batch materials and 3) proper distancing of an optional spray manifold for introducing liquid additions on the downswing side of the agitator, resulting in uniform solids/liquids distribution.

One-piece welded construction, together with heavy-gauge walls and fully reinforced end panels, make these vessels extremely rigid, allowing for exceptionally tight agitator-to-vessel wall tolerances. This, in turn, minimizes residual product in the trough following discharge, reducing material waste and cleaning time.

MUNSON Horizontal Agitated Blenders are offered with ribbon, paddle and plow agitators in many specialized designs to suit each application with top efficiency.

MUNSON blenders are available constructed of a variety of materials, including but not limited to carbon steel, #304/304L and #316/316L stainless steel, abrasion-resistant steel (AR-200/235), duplex stainless, Hastelloy, titanium and other exotics.

Interior finishes range from a standard clean mill finish to ultra-high sanitary finishes, including 2B, #4, and #7 mirror pharmaceutical finishes to sanitary USDA Dairy finishes with electroplating and chemical passivation. Interior weld polishes range from standard 80 grit clean welds to 240 grit radiused and polished welds.

In addition to full-scale machines, MUNSON offers small-scale equipment such as this 1 cu ft (.03 cu m) ribbon blender, for laboratory testing, pilot plants and small production runs.


• Capacities from 1 to 1150 cu ft (33 m³)
• Designs from heavy duty to extreme heavy duty
• Extensive selection of drives, seals, agitators and discharge gate designs
• Low or high pressure ASME-code jackets for steam, hot water, oil or coolant
• Tight-tolerance construction, minimizing residual material following discharge
• Flanged agitator shafts for vertical removal, conserving floor space
• Batch or continuous configurations


MUNSON® agitators are equipped as standard with a flange-mounted shaft that can be lifted vertically for easy removal and servicing. The design also eliminates the need for gasketing in the material path, and the need to reserve floor space for removal of the agitator horizontally through an end panel. (Single-piece agitators with integral journals also available.)

Heavy-wall, wide diameter, hollow agitator shafts are stronger and more rigid than solid shafts. Precision-machined, solid journals are supported by heavy pillow-block bearings for ultra-high strength and rigidity. Thick, one-piece, solid support arms extend fully through the main shaft and are fully seal-welded, adding to the extremely rigid construction of these blenders, allowing unsurpassed agitator-to-vessel wall tolerances.

Double Helix Split-Ribbon Agitators

Split-ribbon agitators are equipped with radial arms that support sections of ribbon-shaped agitator blades mounted in a semi-helical arrangement. Blades extending to the vessel wall are pitched to move material in one direction, while inboard blades are pitched to move material in the opposite direction. Originated by MUNSON, this split-ribbon design blends more rapidly and thoroughly than continuous ribbon elements. It also provides greater surface area than paddle or plow elements, while blending a wider range of free-flowing materials including low-viscosity slurries, typically in 5 to 10 minutes, making this the most popular element for horizontal agitated blender applications.

Enhanced Paddle Agitators

Paddle agitators consist of shafts with radial arms that support numerous, short paddles that move the material in smaller zones over shorter distances with greater cutting action than ribbon blades, preventing the entire batch from being turned on its axis. While this increases cycle times marginally, paddle agitators can handle materials that interlock, flow poorly, or tend to "log roll" when using ribbon agitators. In addition, paddle agitators can handle certain high-viscosity slurries and abrasive materials more effectively than ribbon agitators. Replaceable hardened-steel wear plates can be bolted to paddle faces for increased abrasion resistance.

Plow Agitators

When used in U-shaped vessels at standard or low speeds, a plow element will "fold" material in short zones, moving it away from the vessel wall in the process. While it will effectively blend over time, a plow element is primarily utilized to keep blended material in motion gently while it is undergoing a chemical reaction or being heated, cooled, moisturized, pasteurized, dried, wetted, or otherwise conditioned — while maintaining blend uniformity.

(Note that standard, slow-speed plow blenders are radically different in form and function from high-speed cylindrical plow blenders shown above.)