Straw Crusher

Equipment Introduction

A straw crusher is a specialized piece of equipment for crushing and processing agricultural crop straw and fibrous materials. It can be driven by an electric motor, diesel engine, or a 30-50 horsepower tractor. The main unit consists of a feeding mechanism, a chopping mechanism, a throwing mechanism, a transmission mechanism, a traveling mechanism, protective devices, and a frame. It features a reasonable structure, convenient mobility, automatic feeding, and reliable safety.

This equipment can crush agricultural crop straw such as corn stalks, wheat stalks, cotton stalks, rice straw, branches, leaves, sawdust, and other woodworking waste into small particles or powdery materials suitable for subsequent processing. It is a core piece of equipment for the resource utilization of agricultural waste.

Equipment Structure and Components:

1. Feeding Device: A hopper or conveyor belt responsible for introducing material into the crushing chamber.
2. Cutting and Crushing System: Composed of a main shaft, rotor disc, hammers (or blades), and bottom cutters (fixed cutters).
3. Screening Device: Located at the bottom or circumference of the crushing chamber, controlling the size of the finished product particle size.
4. Power and Transmission: An electric motor or diesel engine drives the main shaft via a belt or coupling.
5. Discharge System: Includes a blower (optional), collection pipes, or a conveyor gantry, achieving negative pressure discharge to prevent dust overflow.

Working Principle of the Equipment

Straw crushers primarily operate based on a combination of impact, shearing, and friction principles.

1. Feeding and Preliminary Processing: Material enters the crushing chamber through the feed inlet. For models with a kneading function, the material is first cut into segments by cutters within the kneading casing.
2. Hammer Mill Crushing: After entering the crushing chamber, the material is crushed by high-speed rotating hammers. Some models employ a multi-stage crushing design, such as a primary crushing roller for initial crushing, followed by further crushing into particles by crushing gears.
3. Friction and Sieving: The crushed material continues to be refined under the friction between the hammers and the sieve plate (screen). Lighter powders pass through the sieve and are discharged from the bottom outlet under the action of centrifugal force and airflow. The coarseness of the crushed material is controlled by the sieve aperture size, which can be adjusted by changing different sieve bottoms.
4. Finished Product Discharge: Material meeting the particle size requirements passes through the sieve and is discharged through the outlet. Material that does not meet the size requirements continues to circulate and be crushed within the crushing chamber.

Applications of the Equipment:

1. Livestock Farming: Production of roughage and silage for cattle and sheep.
2. Biomass Energy: Pretreatment of biomass pellet fuel and briquettes.
3. Edible Fungus Cultivation: Production of culture medium materials for mushrooms such as shiitake and oyster mushrooms.
4. Papermaking and Wood-based Panels: Provision of papermaking fiber raw materials or particleboard filler.

Applicable Raw Materials for the Equipment

The straw crusher is adaptable to a wide range of raw materials, mainly including the following categories:

1. Agricultural Crop Straws: Corn stalks, wheat stalks, rice straw, rice husks, bean stalks, sorghum stalks, cotton stalks, peanut vines, peanut shells, sweet potato vines, grain straw, etc.
2. Plant Stems and Leaves: Bark, branches (less than 5 cm in diameter), leaves, weeds, alfalfa, tobacco, sweet potato vines, vines, etc.
3. Forestry and Processing Residues: Sawdust, wood shavings, wood chips, bamboo and wood powder, fruit shells, etc.
4. Other Biomass: Traditional Chinese medicine, konjac, hemp, starch, distiller’s grains, furfural, charcoal, activated carbon, soybean meal, cotton, etc.
5. Both dry and wet materials are acceptable: The straw crusher can crush various dry and wet agricultural crop straws. However, it should be noted that when the moisture content of the straw exceeds 15%, the material is prone to sticking together, which may cause blockage at the feed inlet.

Equipment Operation and Maintenance Methods

1. No-load Start: After starting, observe whether the rotation direction is correct. Feeding can only begin after the speed stabilizes.
2. Uniform Feeding: Feeding hard objects such as iron blocks, stones, and wood blocks is strictly prohibited to prevent damage to the blades or penetration of the machine casing.
3. Lubrication and Maintenance: Add grease to the bearings every 8-10 hours of operation; regularly check the belt tension.
4. Wear Inspection: Regularly check the wear condition of the hammer blades. If one end is worn, it can be turned around for use. If severely worn, the entire set should be replaced to prevent vibration.

Common Equipment Problems and Solutions

Application of equipment in production lines

In organic fertilizer and biomass pellet production lines, straw crushers are usually located in the raw material pretreatment section:

Straw collection → Pretreatment (cutting/flattening) → [Straw crusher] → Ingredient mixing → Fermentation/granulation → Finished product

Core role:

1. Particle size control: crush the long straw to 1-50mm (or finer) to meet the particle size requirements for subsequent fermentation or granulation;
2. Increase in specific surface area: The specific surface area of the material after crushing is significantly increased, which is beneficial to microbial decomposition and fermentation reactions;
3. Mixing uniformity: Fine powdery materials are mixed more evenly with livestock and poultry manure, fungi and other auxiliary materials to improve fermentation efficiency;
4. Suitable for multiple processes: The crushed straw can be directly used in various downstream processes such as feed processing, organic fertilizer fermentation, and biomass pellet pressing.

Target Customers for the Equipment:

1. Integrated Crop-Livestock Farmers: Farmers and herders who need to handle straw processing and feed production themselves.
2. Biomass Processors: Investors who convert waste straw into high-value-added fuel or raw materials.
3. Environmental Management Units: Cooperatives responsible for addressing the risks of field burning and promoting the comprehensive utilization of straw.

Analysis of the advantages and disadvantages of the equipment