Vermeer Australia provide suggestions on considering the right grinder options. Grinders can be used for applications such as recycling or land clearing operations. Improvements have been made to grinders, making the distinction between tub grinders and horizontal models more obvious. Once a buyer has settled on a grinder type, a wide range of options and horsepower capacities can be chosen. Chris Nichols, Product Manager, Vermeer Environmental Product Group, provides advice in choosing the right grinder model.
According to Nichols, tub grinders perform better with heavy, large-diameter material such as stumps and root balls. However, horizontal models are suitable in processing longer raw materials. This is because while processing longer materials, long branches may be difficult to feed in a tub grinder. Horizontal models have long feed tables and conveyors that guide materials into the grinder, avoiding the material placement and manipulation.
Nichols adds that extra-long feed tables on trailer-mounted Vermeer horizontal grinders allow for loading of long materials without additional cutting. This can be beneficial in land clearing, recycling and storm cleanup applications.
Smaller loading equipment can be used for horizontal grinders, because they have a lower feeding height than a tub grinder. This can be a major factor, depending on the auxiliary equipment that a buyer or renter has on-site.
These grinder categories sometimes come with options that are specific to each. For example, Vermeer Australia offer both track-mounted horizontal units and conventional towed models. In a situation where a single job site may have several debris piles, such as a land clearing job, the self-propelled track-mounted option can be efficient. So instead of towing the machine, it can be moved by the operator, possibly into areas where it could not be towed earlier.
Vermeer Australia’s tub grinders offer both loader and non-loader options.
Among the primary advantages of having a grapple loader on the tub grinder is better visibility of the tub, so operators can load material more efficiently. It also helps the operator identify and clear contaminants mixed with materials. Self-contained loaders also eliminate the need for extra pieces of equipment, because transporting or renting a loading unit is not required.
Non-loader machines are common on work sites that include a fleet of multi-purpose loading equipment. Some non-loader tub grinders require multiple auxiliary loaders to meet the production capabilities of the machine.
Grinders in the market range from 100 HP to 1600 HP models. The two factors to be considered while selecting a grinder size include volume and size of material to be processed and necessary mobility.
According to Nichols, customers representing a municipal landfill or private recycling operation may require a unit with high-volume capacity as it is likely that a high daily volume of material can be expected in one central location. In such cases, setup and mobility of the unit is not nearly as important as the necessary capacity.
Advancements are also addressing what have in the past been two primary concerns about owning and using any type of large grinder, maintenance and safety.
As with any machine, proper preventive maintenance for a grinder is crucial to its longevity and productivity. Hammers, teeth, hammer shafts, anvils and screens are high wear items. Due to the difference in grinding materials and varying amounts of use from application to application, it is difficult to formulate a specific rule of thumb for average wear or longevity. Key variables include how well the raw material is cleaned, how fine the material is ground and how effectively the operator prepares the material.
In the past, some grinder owners have resisted regular maintenance of teeth and hammers, particularly because of the time involved. According to Nichols, if components such as hammers are allowed to wear without proper maintenance, the hammermill could go out of balance and its vibration will cause excessive bearing wear and other vibration-related issues.
Vermeer Australia are manufacturers who address the issue of maintenance with their patented Duplex Drum System for tub and horizontal grinders. The Duplex Drum System offers a 35% increase in rotational inertia with a 10% weight reduction, says Nichols. It offers the operator the ability to change out any individual hammer within minutes without removing other hammers. This system is more efficient than the conventional ‘pin and plate’ drums. The hammers also reverse for nearly double the life span and the drum skin adds life by protecting them from wear and tear.
Owners must be aware that grinders are aggressively processing materials, so there may be times when debris is thrown, especially if prohibited objects are mistakenly introduced into the grinder.
This drove Vermeer Australia to develop their patented Thrown Object Restraint System (TORS) for tub grinders and the Thrown Object Deflector (TOD) for the horizontal models. The TORS can reduce the amount and distance of thrown objects down to 1/5 of that of normal grinders, allowing crews to operate the machine in a much smaller area. Vermeer Australia’s tub grinders also feature a Falling Object Canopy, which is positioned directly above the ground control panel, providing falling object protection for the operator standing at the controls. The tub and horizontal models feature standard remote-control operations, which can position the operator well out of the restricted areas.
According to Nichols, manufacturers like Vermeer are coming up with innovations that increase productivity and efficiency on the job site, make maintenance easier, increase the longevity of the unit and include innovative safety features.
Nichols stresses on keeping a regular maintenance programme that will increase the life of a grinder. It is important to check the hammers and teeth every day as overlooking or ignoring potential problems can lead to decreased productivity or unnecessary wear and tear.