Vibrating screening machine for wood chips

The moisture content of wood chips fluctuates between 8% and 18%. When the moisture content exceeds the critical value of 15%, the softening of lignin easily leads to the formation of flocculent agglomerates with a diameter of 5-20mm. This characteristic requires that the screening equipment must have the ability to deagglomerate. Vibrating screening machine for wood chips uses a dual-mass vibration system to construct a three-dimensional deagglomeration field on the screen surface, so that the wood chips can complete the dual process of agglomerate rupture and particle size separation during the throwing motion. The screening range of the equipment covers the particle size range of 0.2-5mm, and can simultaneously achieve metal impurity removal, particle size classification and fiber bundle dissociation.

Working principle of Vibrating screening machine for wood chips

The Vibrating screening machine for wood chips adopts the technology of reverse synchronous rotation of dual vibration motors. By adjusting the motor installation angle (usually 5°-10°), the exciting force is superimposed in the vertical direction to form a linear motion trajectory. This movement mode makes the wood chips show three-stage movement on the screen surface: throwing movement in the initial acceleration stage (height 50-80mm), sliding movement in the medium speed stage (stroke 100-150mm), and flipping movement in the final stage (angle 30°-45°), which effectively destroys the fiber agglomerate structure.

According to the characteristics of wood chip moisture content, the equipment is equipped with a variable frequency speed regulation system. When the moisture content of the feed is detected to be more than 10%, the vibration frequency is automatically reduced from 1200r/min to 900r/min, and the amplitude is increased to 4.5mm, which promotes the dispersion of agglomerates by extending the material throwing time. For long-fiber materials, an asymmetric vibration mode is adopted to make the screen surface produce a slight torsional vibration and cut off the fiber winding path.

Structure of Vibrating screening machine for wood chips

The screen box is welded with Q345 steel plates with a thickness of 4-6mm, and a reinforcing rib plate is set inside to ensure that it does not deform when processing high-density wood chips (stacking density 0.3-0.5t/m³). The adjustable range of the screen box inclination is extended to 0-7°, and the hydraulic device can achieve stepless adjustment to meet the processing needs of wood chips with different fluidity.

The screen system adopts a modular design and is equipped with three layers of screens: the upper layer is a 3mm square hole screen, the middle layer is a 1.5mm oblong hole screen, and the lower layer is a 0.75mm woven screen. For coniferous wood chips, the surface of the middle screen is sprayed with Teflon anti-stick coating to reduce the amount of resin adhesion. The screen fixing device adopts a quick clamping mechanism, and the screen changing operation time is shortened to 8 minutes.

The shock absorption system consists of a composite shock absorption unit composed of rubber springs and air springs. The vertical stiffness coefficient is optimized to 650N/mm, which effectively isolates vibration transmission. For high-noise working conditions, damping shock absorbers can be optionally equipped to control the noise value of the equipment at 1 meter below 78dB.

Application of Vibrating screening machine for wood chips

In the field of wood-based panel production, the equipment is used to purify particleboard raw materials, and removes metal impurities (>2mm) and fine powder (<0.5mm) through a double-layer screening system. For wood chips used in adhesive production, a three-level screening system is configured to achieve accurate separation of three particle sizes of 0.5-1mm, 1-2mm, and 2-3mm, and the particle size variation coefficient is controlled within 8%.

In the biomass power generation industry, the equipment undertakes the task of fuel particle classification. By adjusting the screen surface inclination and vibration parameters, wood chips are divided into three levels: coarse material (>5mm), molding material (2-5mm), and fine powder (<2mm).

Special application scenarios include:

Chemical raw material processing: equipped with explosion-proof vibration motors and grounding monitoring systems, safe operation in combustible dust environments.

Preparation of food-grade wood chips: Made of 304 stainless steel, with a surface roughness of Ra≤0.8μm, it is used for purification of edible fungus cultivation substrates.

Micro-wood chip recovery: Equipped with ultrasonic anti-blocking device, fine wood chips <0.1mm are graded, and the recovery rate can reach more than 90%.

The technical value of Vibrating screening machine for wood chips is reflected in the deep adaptation of material characteristics. The equipment builds a screening process package that adapts to different moisture content, fiber length and particle size distribution through the synergy of variable frequency vibration source and adjustable inclination screen box. Equipment selection should be based on material test report, focusing on matching screen aperture, vibration intensity and anti-blocking device to form a customized solution for specific working conditions.