Shrimp Peeling Machine

Overview

A shrimp peeling machine removes the shell and the dorsal vein from raw shrimp without hand labor. The core idea, used in nearly every commercial peeler since the Lapeyre design of the 1940s, is a bed of paired soft rubber rollers. The shrimp ride along the top of the rollers while the rollers turn inward and pull the loosened shell down between them. Shell goes through the gap, meat stays on top. A modern line wraps that roller bed with an Infeed & Orientation Section that meters and aligns the shrimp, a Wash Water System that floats away debris, a Deveining Station that cuts and flushes the vein, a Separation Section that splits meat from shell, and a Takeaway & Grading stage that sorts the finished meat by size.

Infeed and orientation

Loose shrimp arrive in totes and are tipped into the Feed Hopper. A Vibratory Feeder Tray meters them onto the bed in a thin, even stream so the rollers are never choked. The feeder pan rides on eight Coil Spring mounts driven by two Electromagnetic Vibratory Drive units. Two Capacitive Level Sensor probes watch the hopper and slow the upstream supply when it fills. A slotted Orientation Drum, turning on a Orientation Drum Shaft carried by two Ball Bearing units, rolls each shrimp so it lies lengthwise before it reaches the rollers. Correct orientation matters: a shrimp fed sideways peels poorly and can jam the gap.

Roller peeling section

The Roller Peeling Section is the heart of the machine. It holds 18 Peeling Roller Pair units mounted across a Roller Bed Frame. Each pair is two Soft Rubber Peeling Roller rollers on parallel shafts, set with a small gap and loaded by Coil Spring tension so the gap opens slightly under a thick shrimp and closes on a thin one. The rollers are 40 Shore A food-grade nitrile, soft enough to grip shell without bruising meat. Six spring-loaded Spring Pinch Bar hold-downs press the shrimp against the rollers so the shell is caught and stripped rather than skidding over the top. Two Roller Bank Drive Shaft assemblies, geared through Helical Gear Pair sets, turn every roller in the bank together. The whole bed sits at an adjustable incline set by two Incline Adjuster screws; steeper angles move product faster, shallower angles give a longer peel.

Wash water and deveining

Water does two jobs. The Wash Water System sprays the rollers through four Spray Manifold bars fed by two Centrifugal Water Pump units, lubricating the peel and washing shell fragments off the bed. The water drains to a Recirculation Tank, passes through a self-cleaning Rotary Drum Filter, and is pumped back, which cuts fresh-water use to 2.5-4.0 m³/h. Flow is gated by Solenoid Water Valve units and watched by a Pressure Sensor.

Deveining happens at the Deveining Station. Four Back Slitter Head units score the back of each shrimp with a thin Slitting Blade, its depth held by a Blade Depth Guide Shoe. Two Vein Wash Jet Bar manifolds then drive 8-14 bar water through High-Pressure Jet Nozzle tips, fed by a triplex High-Pressure Jet Pump, to flush the exposed vein. Two Vein Brush Roll rolls wipe out anything the jet leaves behind.

Separation and grading

After peeling, meat and loose shell travel together and must be split. The Separation Section runs the mix over a Vibrating Separation Screen where small shell drops through the Separation Mesh Panel, then through a Flotation Channel where light shell floats and is skimmed while dense meat sinks. Shell is carried off by two Shell Discharge Auger conveyors. The cleaned meat moves onto the Takeaway & Grading stage: a Takeaway Belt Conveyor feeds a diverging Diverging Roller Grader that drops each shrimp into a Grade Discharge Chute by size, with a final Inspection Table for hand checks.

Drive, control and frame

Power comes from four washdown Geared Drive Motor units, each built on a Stator Assembly and Rotor Assembly in a sealed Gearbox Housing, driving the rollers, conveyors and augers through Drive Belt and Stainless Roller Chain loops. Everything is run from the Control Panel, an IP66 Control Enclosure Box holding a PLC Module, four Variable Frequency Drive drives, a HMI Touchscreen, and a Power Supply. Three Emergency Stop Button stations cut motion at any guard. The machine stands on a welded Welded Main Frame with sloped, drainable surfaces, Drip Pan trays, and removable Washdown Guard Panel covers so the line can be hosed down between shifts.

Materials, variants and use

Wetted parts are 304 or 316 stainless and food-grade nitrile, the two materials that survive constant chlorinated washdown. Capacity scales with bed width and roller count, so a small plant might run a 6-pair bed at 450 kg/h while a large processor runs 24 pairs above 1,400 kg/h. Variants add a steam pre-cook section ahead of the rollers for cooked-peel product, or swap the back-slit deveiner for a pull-vein head on larger counts. The machine is used by frozen-seafood processors, breading and value-added plants, and canneries, anywhere shrimp must be peeled at a rate no hand crew can match.