Fruit Pulper and Finisher

Overview

A fruit pulper and finisher turns whole soft fruit into a smooth, seed-free, skin-free pulp in one continuous pass. It is the core machine in any line that makes tomato paste, mango or guava puree, fruit juice, jam, or baby food. Washed fruit goes in at one end; finished pulp drains from the bottom while the skins and seeds, called pomace, are pushed out the far end. The separation is mechanical. A shaft of paddles spins inside a perforated screen and beats the fruit against it, so the soft flesh and juice are forced through the holes while anything too large or tough to pass is carried along and ejected.

The machine here is a two-stage design. Feed enters through the Feed Hopper and Inlet Auger, passes through a coarse Pulping Chamber, then a fine Finishing Chamber. Pulp collects in the Pulp Collection and Outlet and pomace leaves through the Pomace Discharge. The Drive turns the beater shaft, the Bearing and Seal Housing carries and seals it, and the whole machine sits on the Frame and Legs under a Control Panel.

Feed

Fruit is loaded into the Charging Hopper, a wide stainless funnel sized to hold a buffer of fruit so the operator can keep working while feeding. A Safety Grate across the top keeps hands and stray objects out of the moving parts. Below the hopper a single-flight Feed Auger meters fruit at a steady rate into the Inlet Throat. Steady feed matters: if the chamber is starved the beaters churn air, and if it is flooded the screen blinds and pulp yield drops. The auger runs in its own Ball Bearing at the tail end so its load is kept off the beater shaft.

Pulping chamber

The first stage does the heavy work of breaking the fruit. Inside the Pulping Chamber Housing the Paddle Beater Shaft spins at 700-1000 rpm. The shaft is built from a Shaft Tube in AISI 316, with Paddle Hub clamps that set each paddle angle and a Drive Key tying the shaft to the drive. Six Beater Paddle beaters on six Paddle Arm arms run a few millimetres clear of the screen. The paddles do two jobs at once. They throw the fruit outward against the Coarse Perforated Screen, a half-cylinder with 1.0-1.5 mm holes, so juice and soft pulp pass through, and their lead angle walks the residue along the screen toward the discharge. Four Wiping Blade rubber blades sweep the inside of the screen so the holes do not pack with pulp and lose throughput.

Hole size sets what comes through. The coarse screen is open enough to take pulp at high rate without crushing the seeds, because crushed seed releases bitter compounds and oil that taint the pulp. Keeping seeds whole until they reach the discharge is one of the main reasons the work is split into two stages.

Finishing chamber

First-pass pulp still carries fibre, fine skin flecks, and small seed fragments, so it moves into the Finishing Chamber for refining. Here the Fine Perforated Screen has 0.5-0.8 mm holes. Six Finishing Beater beaters on Beater Arm arms run with a tighter clearance than the coarse paddles, so they rub the pulp through the fine screen rather than beating it hard. The Finishing Chamber Housing drains the smooth pulp down to the outlet. A Lead Adjuster changes the beater lead angle, which trades pulp yield against the dryness of the pomace: a steeper angle moves residue out faster and keeps yield up, a shallower angle holds the fruit in the screen longer and dries the pomace at the cost of a little throughput.

Pomace discharge and pulp outlet

What does not pass either screen is concentrated by the Discharge Cone at the far end and drops out the Pomace Chute into a bin or a return conveyor. A spring-loaded Back-pressure Flap, held by a Coil Spring, sets how long fruit dwells in the screen before it is allowed to leave, which is the operator's main control over yield and pomace moisture. Finished pulp from both screens falls into the sloped Collection Trough in AISI 316 and runs to the Outlet Spout, where a pump or a tank takes it. A Drain Valve empties the trough at the end of a batch, and Tri-clamp Fitting sanitary fittings let the outlet be stripped for cleaning.

Drive and shaft support

The beater shaft is turned by the Drive. A TEFC Drive Motor of 3.7-5.5 kW, built from a Stator Assembly and Rotor Assembly on two Ball Bearing bearings, drives a Helical Gearbox through twin Drive Belt V-belts running between the Motor Pulley and the Shaft Pulley. The gearbox uses a Helical Gear Pair in a Gearbox Housing with Oil Seal shaft seals to bring motor speed down to beater speed. A Belt Guard encloses the belts and the motor sits on a Tensioning Rail that slides to set belt tension.

Where the shaft enters the wet chamber the Bearing and Seal Housing does the sealing. The Drive-end Housing and Idle-end Housing carry Ball Bearing bearings kept dry by Oil Seal lip seals and an O-Ring Set. Each end has a Flush Ring that feeds clean water to the seal so pulp cannot pack into the bearing and wreck it.

Frame, cleaning, and control

The machine stands on the Base Frame on four Adjustable Leg legs with Levelling Foot sanitary feet for levelling. Sheet Metal Panel cladding and a hinged Splash Cover contain splash while running and lift off for washdown. Because pulp is a food product, every wetted part is AISI 304 or 316 and the screens, paddles, and trough come apart without tools so they can be cleaned and the screen swapped between fruit types.

The Control Panel sits in a sealed Control Enclosure. A Motor Starter switches and protects the motor, a Emergency Stop cuts it at once, and a Cover Interlock stops the beater shaft if the splash cover is opened. A small board with a Bare PCB, an Microcontroller, SMD Passive (R/C/L), and a pair of Relay relays handles the run logic, with Connector field connectors and a Wire Bundle for the internal wiring.