At GrinderCrusherScreen we pride ourselves in selling the customer what they need, not necessarily what they ask for. A very common request is for a larger, more powerful grinder, as their current grinder cannot keep up. A larger grinder is not always the answer. We must know the following: Type of material, Size of screens in grinder, Existence of contaminants like steel, Amount of dirt in material, and Whether they want a single, double or triple ground material.
For example: If our customer has stumps and have their grinder equipped with demolition screens, then I will agree a larger or additional grinder is needed. If this customer is not shearing / size reducing before feeding them into the grinder, I will definitely suggest they shear up the stumps into smaller pieces. This will not only increase production with their existing grinder but will protect the grinder from additional abuse.
Let’s assume this is not the case and the customer grinding wood needs to make a double ground mulch material. If the grinder is equipped with 2” screens, we recommend a larger screen, like 5”, or a demolition screen to do the primary reduction then use the 2” screen for the secondary grinding. In many instances we recommend running the primary grinder into a secondary grinder instead of purchasing a larger grinder. Using two machines or running the material twice through the same grinder will result in less wear and tear on your grinder.
Many customers have contaminants in their materials and are experiencing catastrophic damage to their grinder on regular basis. In this instance we recommend a high torque, slow speed shredder to do the primary grinding. This shredder must have a magnet, to remove the steel, and then discharge the material into a tub or horizontal grinder. This will eliminate 90% of the issues related to contaminants.
We also highly recommend the use of screening plants to remove the fines and finished ground material. This will minimize the amount of material that needs double ground. I want to preface that you want to overfeed the screener so that approximately 20% of the fines go into the mulch product. This is important since if you remove 100% of the fines from the mulch, your finished material will look rough, like chopped wood, not mulch. The fines smooth out the edges of the wood giving it that nice, premium mulch you are looking for. By screening, we can also reduce the amount that needs ground by up to 30-50%. Another added benefit is that you have a very fine soil amendment that will need to be composted but then ready to sell for a premium price.
The above is a good basic guideline to consider when considering purchasing a larger grinder. Since every customers’ needs are different though, we will be happy to discuss yours.