Pulverizer Attachment Product

Overview

A pulverizer attachment is designed specifically for grinding concrete rubble into consistent fine aggregate suitable for reuse in road base, fill, or new concrete. Unlike a concrete crusher that emphasizes jaw force, the pulverizer focuses on aggressive tooth-line contact and working surface area. Two large jaws lined with hardened tungsten-carbide or alloy-steel teeth meet and work the material by rolling it between them in a process called attrition grinding. The teeth break bonds between the cement paste and aggregate, eventually reducing the rubble to 5–25 mm pieces. The attachment mounts to a 25–50 tonne excavator via a quick-change coupler and rotates 360 degrees continuously for efficient working.

How it works

The heart of the pulverizer is the pulverizer-attachment-jaw-set. A Fixed Jaw Assembly bolted to the Frame & Pivot Structure is the lower anvil. An Moving Jaw Assembly, pinned on the Jaw Pivot Axle, swings upward and downward. Both jaws are lined with rows of Tooth Insert carbide teeth set 20–30 mm tall, spaced about 40–60 mm apart. When the excavator operator opens the proportional Directional Valve, an Hydraulic Jaw Cylinder pressurizes and drives the moving jaw closed. As the jaws meet, the teeth grip the rubble and pull it into the center of the jaw opening. The rubble is subjected to both crushing (direct closure force) and attrition (teeth rolling over it) as the jaw cycles open and closed.

The grinding action is progressive. Rubble enters the jaw gap near the jaw tips; as the jaws close, pieces are gripped and worked deeper into the cavity. The smaller fragments drop clear, while larger pieces are held and worked on successive jaw cycles. The Tooth Mounting Bolt fasteners must be premium grade (8.8 or 10.9) because pulling forces on the teeth are severe — loose teeth cause misalignment and lost grinding efficiency.

The pulverizer-attachment-cylinder-relief-valve limits peak jaw pressure to 250–320 bar, protecting the excavator pump from stalling and preventing the attachment from tearing itself apart during overload. The End Cushion metering valve at the cylinder rod end meters flow during the last 50–100 mm of jaw closure, preventing impact shock.

The 360° Rotator Motor & Gearing is a separate hydraulic circuit. The Rotator Motor, powered by continuous pump flow, drives the Rotator Gearbox, which reduces speed to 5–15 rpm. This rotator shaft emerges from the attachment and couples to the mounting bracket on the excavator stick, allowing the entire attachment to spin. As it rotates, the two jaw faces sweep across the material pile, enabling the operator to maximize tooth engagement and grind material evenly.

Wear is managed through swappable components. The Fixed Jaw Teeth and Moving Jaw Teeth are bolted to the jaw faces and removable. When carbide inserts chip or dull after 200–500 operating hours (depending on material type), individual Tooth Insert studs can be unbolted and replaced. The Jaw Liner Plate and Wear Backing Plate backing plates absorb some of the wear, extending jaw body life. After several tooth changes, the jaw face itself may need re-facing or replacement.

The Hydraulic Coupler & Hoses interface connects the excavator pump to the attachment via quick-disconnects. The Jaw Pressure Hose carries load-sensing oil driving the jaw cylinder; the Jaw Return Hose routes exhaust back to the reservoir. The Rotation Hose supplies the rotation motor continuously. A Pressure Gauge mounted on the jaw pressure line lets the operator monitor load and sense when material resistance increases (indicating finer rubble, longer cycle).

The Frame & Pivot Structure is a robust welded box. The Jaw Pivot Axle must handle all the shear and bending from jaw closing forces, so it is oversized and fitted with bronze Jaw Pivot Axle bushings to minimize play. The Side Brace members add torsional stiffness, preventing jaw binding.

Energy consumption is significant. A pulverizer running continuously on a 30 tonne excavator can consume 80–120 L/min at full jaw pressure and rotation. The excavator engine must be sized accordingly. Typical applications are on-site sorting and grinding of mixed concrete and masonry rubble during demolition, producing material for immediate landfill reduction or aggregate recovery.