This section primarily concerns diesel powered tub grinders. Tub grinders are primarily built to handle wood and green waste material. Bark, brush, logs, stumps, wood construction and demolition material, leaves, compost, etc. can be reduced or recycled into a salable product. (Lighter duty tub grinders may be used to grind feed stock. Tub grinders can turn a waste material into a valuable, usable product. Mulch, colored mulch, boiler fuel and compost are just a few of the finished products you produce with the right tub grinder. Some tub grinder owners use them to reduce the volume of their material to minimize trucking and save on dump or tipping fees.
If you are just learning about tub grinders there are three basic components to the grinder that really matter. The first is the engine. The engine will help determine the true capability of your grinder. Higher horsepower will generally give you more flexibility in the type of material you can grind and better production numbers. Logs and stump work well with larger engines.
The second component is the mill size and type. Tub grinder mills are cylindrical in shape and are measured by the length of the cylinder/mill. The larger the mill, the more production you might expect. The hammer type will be either a fixed hammer or a swing hammer set up. Harder material like stumps and logs are best ground using a fixed hammer grinder. Larger tub grinders are generally set up with fixed hammers in the mill to create a harder, more rigid impact. However, some large grinders can utilize swing hammers. A swing hammer machine is said to be slightly better at grinding smaller material sizes like bark and wood chips. They also create a more uniform finished product. The other advantage is that swing hammers may minimize damage to your grinder if you happen to try to grind a steel i-beam.
The third component is the tub diameter or size. Tub grinders are measured at the very top of the tub or flare. For example, a Duratech HD 10 measures 10’ at the flare but approximately 8’6” between the tub walls. The tub size is important because you want to make sure that your support equipment is going to work properly. For example, you do not want to load a 10’ tub with an 11’ loader bucket. Also, the larger the tub size, the higher the lift over. You want to be sure your Bobcat, loader or excavator is going to be able to feed the tub grinder properly.