The reason why shredding has become an indispensable pretreatment process for all solid waste treatment methods is mainly based on the following advantages:
(1) Shredding reduces the voids of solid waste and increases its bulk density. For landfill treatment, the crushed waste is placed in the landfill and compressed, and its effective density is 25% to 60% higher than that of the unbroken material. It reduces the frequency of landfill staff covering with soil, and at the same time increases the useful life of the landfill. In addition, for landfills, after shredding treatment, the pores between solid wastes are smaller, which can more effectively remove mosquitoes and flies, and solve the problem of odor, thus reducing the possibility of insects and rodent disease transmission.
(2) For incineration, after the solid waste is crushed, the original complex and uneven waste becomes more uniformly mixed, and the specific surface area increases, which makes it easy to achieve stable, safe and efficient combustion, and recover the potential heat value as much as possible.
(3) For composting, shredding can also improve the efficiency of composting; at the same time, because of the reduction of porosity, the loss of heat is also less, which is more suitable for high-temperature composting.
(4) The increase in waste bulk density makes storage and long-distance transportation more cost-effective and easy to carry out.
(5) Provide the required selected particle size for the sorting, so that the original associated minerals or the monomers such as the connected minerals can be fully dissociated, thus improving the recovery rate and taste of the effective components.
(6) Through shredding, it can prevent or avoid the damage of large, sharp materials to the subsequent process equipment.