Shredding and briquetting wood waste

Depending on the type of machine, items such as offcuts, wood shavings, pallets, chipboard and other wood waste can be shredded. Long pieces of scrap timber are a typical application for GHZ horizontal shredders. Whether a specific machine is suitable depends on the dimensions, timber species, moisture content, foreign materials, required throughput and desired end size.

During chipping, bulky wood waste is converted into wood chips or shavings. During briquetting, loose, sufficiently homogeneous material is compressed under pressure, without the use of binders, to form compact briquettes. Both processes therefore serve different purposes and can be combined.

No. Wood shavings, sawdust or wood dust may be suitable for use directly in a briquette press, provided that the moisture content, particle size, bulk density and purity are appropriate. Chunks or excessively coarse residues, on the other hand, must be pre- or post-crushed. A material test will determine which process is required.

With GAZ single-shaft shredders, it is primarily the mesh size of the screen used that determines which particles can pass through the cutting chamber. The actual result is also influenced by the material, moisture content, rotor design, condition of the blades, feed rate and operating parameters.

Typical materials include sufficiently homogeneous planer shavings, sawdust, wood dust and suitably processed wood chips. Suitability depends on the type of material, residual moisture content, particle size, bulk density, homogeneity and the absence of foreign matter, as well as the specifications of the respective baler. Generalised approvals are therefore not appropriate.

Compaction takes place without the use of any additional binder. However, this is subject to the material being suitable for the chosen compaction process and meeting the required material specifications.

This may be possible if the heating system or wood gasifier is approved for the fuel in question. The decisive factors are the system manufacturer’s requirements, as well as the type of wood, moisture content, absence of foreign matter, particle size and, in the case of briquettes, the required quality. Coated or contaminated wood must not be treated in the same way as untreated waste wood across the board.

This cannot be determined solely by the size of the facility. The decisive factors are the type and quantity of waste material, maximum dimensions, available floor space, existing extraction and conveying systems, and the planned method of recycling. A horizontal shredder may be appropriate for long pieces of waste. For mixed, chunky wood waste, a single-shaft shredder is often the best choice. For loose wood shavings, a briquette press is recommended.

Yes, GROSS has supplied combined systems in which crushed material is fed to a briquette press via a screw conveyor or a belt conveyor. The specific automation required depends on the material flow, buffer storage, discharge, safety systems, control system and the desired mode of operation.

Foreign matter should, where possible, be avoided prior to processing or specifically removed (e.g. using a magnetic roller or a magnetic separator). Whether and where removal is necessary must be determined on the basis of the material and the plant. This is no substitute for thorough material inspection.

Throughput depends on the material and the machine. Factors that influence this include the type of material, dimensions, residual moisture content, screen mesh size, rotor and drive configuration, feeding method and, in the case of briquetting presses, the compressibility of the material. A reliable figure can only be provided once these parameters have been clarified or following a material test.

The cost depends on the machine, the material, the workload and wear and tear. GROSS offers original spare parts and wear parts, as well as repair and maintenance services for both new and older model ranges.

Yes. Demonstrations and trials using customers’ materials can be arranged at the technical centre.