1. Perfect In One Pass /
2. Horizontal Grinders vs Tub Grinders

Horizontal Grinders Vs. Tub Grinders

Horizontal grinders offer many advantages over tub grinders, including superior particle size control, enhanced efficiency, and greater versatility. Our "Perfect In One Pass" design maximizes these inherent benefits, allowing operators to efficiently produce high quality end materials from a wide range of raw materials. 

Finished Product Control

Tub grinders are typically used mainly for primary grinding of raw materials and are not capable of efficiently achieving finished product specs from many forms of wood fiber and other raw materials.

Horizontal grinders allow operators to more efficiently achieve small particle sizes required for boiler fuel, landscape mulch, animal bedding, and other finished products. 

Rotochopper horizontal grinders are widely recognized for superior particle size control. Our commitment to "Perfect In One Pass" equipment innovation allows operators to conveniently produce high quality biomass fuels, colored and natural landscape mulch, animal bedding, and many other uniformly sized end materials. Our patented colorizer system allows operators to produce beautiful colored landscape mulch in a single pass. 

Horsepower Efficiency

Tub grinders rely on the force of gravity and tub rotation to regulate feed rates, which means that efficiency can vary drastically with the consistency of feedstocks. For example, tub grinders can have difficulty feeding lighter materials, like tree limbs, slabs, and corn cobs, which may "float" above the rotor without sufficient weight to force them into the rotor teeth. On the other hand, heavier feedstocks, like bark, dense round bales, and compost, can feed too quickly, causing rotor lugging or even plugging. Because the rotor in a tub grinder is constantly exposed to oncoming feed material, with nothing to hold the material back from the rotor, feedstock can be pulled into the grinding chamber too quickly. Tub grinders may experience extreme fluctuations in horsepower efficiency, as feed material alternates between floating above the rotor and being sucked into the grinding chamber.  

Horizontal grinders provide better control over feeding rates because feedstock is delivered at a steady speed. The powerfeed drum ( feed roll) of a horizontal grinder digs into feed material to provide a level of feed rate control much greater than a tub grinder can achieve. If raw material feeds too quickly, the powerfeed drum and infeed conveyor can be reversed to allow the engine or electric motor to recover.

Rotochopper horizontal grinders feature the most aggressive powerfeed drum design in the industry, providing controlled feed rates for forestry slash, wood chips, pallets, slabs, and a wide range of other feedstocks. Our patented slab ramp allows operators to efficiently process pliable feedstocks that can instantly plug other grinders, such as palm fronds and tomato vines. When equipped with our unique bale pre-processing system, our horizontal grinders offer unmatched efficiency for grinding round bales.

Learn more about Rotochopper infeed systems.

Learn more about our bale processing systems.

Safety

Tub grinders are notorious for hurling objects long distances at considerable speeds. Because the rotor is exposed at the bottom of the tub, a tub grinder can easily throw objects unless the tub is packed with raw material. Some tub grinders incorporate covers or deflectors to minimize the hazard posed by flying debris and thrown objects, yet the occurrence of thrown objects is still greater for tub grinders than other grinding systems.

Horizontal grinders also have inherent safety concerns, including the possibilities of thrown objects. Like tub grinders, horizontal grinders require conscientious, trained operators who always follow safety policies. Horizontal grinders, however, allow operators to more conveniently manage their safety policies by confining the thrown object hazard zone to a much smaller space that extends forward and slightly outward from the feed opening. A horizontal grinder generally will not throw objects nearly as high or far as a tub grinder can because the top portion of the rotor is not exposed, as it is in a tub grinder.

Rotochopper horizontal grinders feature a down-cut rotor design, further limiting the distance that thrown objects may travel. As with all high-speed grinding equipment, the thrown object hazard zone for a Rotochopper grinder requires safety precautions, including the use of enclosed cab loading equipment and personal protective equipment.

Overall Benefits of Horizontal Grinders

As one of the first kinds of equipment capable of processing wood waste and other forms of waste, tub grinders have helped advance the recycling industry. But since the development of horizontal grinders in the early 1990s, tub grinders have been steadily replaced by horizontal grinders because of their superior efficiency and finished product control. The "Perfect In One Pass" Rotochopper advantage optimizes these inherent benefits by delivering the results you need from your raw materials at low operating costs.