About Industrial Shredders: Applications and Selection Criteria
Shredders play an essential role in many applications, including manufacturing, recycling, solid waste reduction, safety, wastewater treatment, oil and gas production, biosolids transportation and production, and more. Shredding offers a multitude of benefits in addition to the most obvious one: size reduction. Shredders are used to process materials used to produce a product or fuel, protect business intelligence by destroying confidential products or documents, recycle products or waste, and shred solids to ensure other equipment or processes run smoothly. Corporations, government agencies, and municipalities employ shredders.
APPLICATIONS
Some industrial applications for reducing solids include the destruction of food, pharmaceuticals, rubber, pallets, steel and plastic drums, furniture, construction debris, tires, containers, corrugated boxes, packaging, labels, and other bulky materials. Industrial shredders are also used for the destruction of documents, X-rays, media such as hard drives and other electronic devices to protect people’s privacy and corporate information.
Municipal applications include recycling centers and smaller shredders with multiple cutting teeth for finer reduction for use in wastewater treatment plants. The recycling industry has found many uses for shredders, such as shredding tires for rubber recovery. This recycled rubber is found in many applications and products, including hot melt asphalt, basketball courts, playgrounds, and shoe products. Rubber is also used in civil engineering practices for road subgrade isolation, fill, and as a fuel as “Tire Derived Fuel.” Waste wood is shredded for recycling and used to make many types of wood products, such as particle board and paper. Plastic bottles are recycled into PET (polyethylene terephthalate) plastic chips for the production of new bottles. Recycling or reusing all of these products through shredding reduces waste in the environment, increases corporate profitability and reduces carbon emissions.
SELECTING THE RIGHT CRUSHER
Type of material to be processed
Different types of shredders excel at processing specific materials. Tree branches are usually shredded with a high speed chipper. However, plastics are most often processed in a granulator (rotary blade cutter); Bulky plastic shapes are often placed in a crusher as the first stage before granulating. When planning to shred automobiles, this type of application is typically accomplished with a hammer mill. Although processing a variety of waste materials may require versatility with minimal noise and dust, a dual shaft shredder may be the optimal solution.
Desired output
Understanding the outlet size requirement will help determine the type of equipment to be installed. Some facilities require the material to be separated, while others may need to regrind and regrind. A single pass crusher will cost less, but if the material needs to be reduced to a very small size and compressed, compaction equipment may be required.
Capacity
Choosing a shredder to handle the correct capacity is important to the success of any installation. Capacity is typically expressed in pounds per hour and is determined by physical size, weight (bulk density), and amount of material to be crushed. Capacity may be limited by the size of the cutting chamber. Please check the capacity rating carefully before purchasing the machine and allow for excess capacity. Using a shredder with a maximum capacity that is too close to the desired capacity can reduce the service life. However, oversizing a shredder by a large margin can lead to excessive energy use and take up too much floor space.
Feeding type
Two basic types of feeding are common: manual and automatic. Hand-fed shredders generally have a hopper and work by manually feeding the material or using a forklift to drop the material. Automatic feeders or conveyors help optimize crusher performance by providing a constant and regular supply of materials to the crusher.
Operational considerations
Portability, safety, and noise are concerns when selecting a shredder. Select the proper location for the shredder because it is not easy to move a machine that weighs half a ton or more. Depending on the material, dust and other airborne particles can be an environmental hazard. Noise is another factor to consider, as some crushers (such as hammermills) generate more noise than others.
Maintenance
Shredders take a great deal of stress and require maintenance to run efficiently. Cutters, blades, or hammers will wear out with normal use and will need to be sharpened, adjusted, or eventually replaced. Consider maintenance, repairs, and ease of obtaining replacement parts when choosing a manufacturer. Always evaluate the maintenance access location when determining where to locate any equipment, including your shredder.
DOUBLE SHAFT CRUSHER
One of the most versatile types of shredders is the twin shaft shredder, such as the Franklin Miller TASKMASTER shredder. These devices employ two stacks of parallel counter-rotating cutters that interlock at low speed with extremely high torque. As cam cutters intertwine with a tight space, they cut, shear, rip, shear, and tear a variety of materials into smaller pieces, typically in a strip or chip-shaped exit shape. The geometry of this twin shaft cutter also makes it very good at feeding irregularly shaped solids. This type of crusher generally does not employ a size screen, so the output particle is determined by the shape of the cutter. Dual shaft shredders can be designed for specific solids such as tires, medical waste, documents, bottles with liquids and more. The details of the application determine the configuration of the unit, although some crushers are specifically designed for a single application and are not versatile in any way. Shredder model numbers generally describe the length and width of the unit’s cutting chamber. The complete unit mechanism typically consists of the main cutter with shafts, cutters, bearings, transmission and housings, bracket, hopper (a funnel as a feed channel) and a controller mounted on the unit or elsewhere.
In operation, the material is fed into the upper hopper of the unit and discharged from the bottom. Some shredder designs can be configured both vertically and horizontally. Specific designs are equipped with advanced shaft seals and sealed housings suitable for handling liquids.
Since there are varying degrees of quality, precision, engineering and care for different sources of crushers, the choice of manufacturer, as well as the type of crusher, can greatly influence the success of the installation.
CRITERIA FOR SELECTING THE RIGHT CRUSHER:
• Is the shredder rated for capacity to meet your requirements?
• Is the shredder made by a manufacturer with long-term experience and a reputation for customer service?
• Can the shredder handle your material in addition to achieving the desired output particle size and consistency you want?
• Is the shredder rated for liquids and solids, if necessary?
• Is the crusher the right cut chamber design and size for your materials?
• Do you have the electric service to meet your energy requirement?
• Is the shredder available with the options or materials you need?
• What are the maintenance requirements?
• Is the crusher robustly designed for long-term reliable operation?
• Does the manufacturer offer support and guidance to assist you in selecting, installing, and supporting the equipment?
IN SUMMARY
As you can see, there are many considerations before selecting a suitable shredder. Gathering all the necessary information to compare with the specifications of the crushers will help to shorten the process of adapting the equipment to your needs. If you are considering recycling, verify that you have the necessary permits. Seeking the experience and advice of a reputable company is a good start and requesting a demo with a sample will confirm the effectiveness of the shredder. Visit the manufacturer’s website to review the company’s history and read some case studies to learn how other companies have used shredders to solve operational difficulties. The last part of the equation is determining your budget. Be aware that some units, while less expensive initially, may be inferior in quality and actually cost more in the long run to operate and maintain.