Potato Tare Line

A taring line developed by RMA Techniek for the inspection of potatoes.

Turner with bunker

When the tipper is empty, a crate of 250 kg of potatoes can be loaded. The barcode scanner can be used to scan the barcode associated with the badge. This way, the system knows which party is crossing the tare line, and all data is immediately stored in the correct file.

After scanning, the start button can be pressed, the box will go up and the potatoes will end up in the bunker through the tilting system. The bunker consists of a receptacle with a conveyor belt underneath so that the bunker can be completely emptied. When the box is empty, it will come down again and it will be visible on the screen when it can be driven away.

Loose soil cleaner

When the bunker is filled, it will run empty and the potatoes will come over the loose soil cleaner. The loose soil cleaner consists of a bar belt with an eccentric, driven shaft mounted in the middle under the belt. Rollers are mounted on this shaft that supports the bar conveyor and the eccentric drive will cause an up and down movement in the bar conveyor. As a result of this movement, most of the loose soil and dust from the potatoes will be removed and will end up through the bar belt in the collection box below.

Stone separator

After the loose soil cleaner, the potatoes fall into the stone separator. This machine has been developed to remove stones and clods from the batch. The stone separator consists of two conveyor belts. One conveyor belt runs in the longitudinal direction of the taring line, this is the product belt over which the potatoes go. The other conveyor belt is advanced at right angles from the stone separator, this is the stone belt.

At the bottom of the stone, the separator is a screw that creates an upward flow at the beginning of the stone separator. This flow will be just enough to prevent the potatoes from ending up on the stone belt but on the product belt. The heavier stones and clods will not be carried along in the current but sink directly onto the stone band. The stone belt turns the stones and clods out of the stone separator into a collection box which is next to the stone separator.

Because in the remainder of the taring line, badges of a maximum of 40 kg will be used, a collection bin with a separate flap of 40 kg has been provided after the stone separator. A level sensor has been placed on this collection tray to see when this collection container is filled. As soon as the bin is filled, the bunker belt, loose soil cleaner, and stone separator will stop rotating.

Washer/Peeler

The washer can be filled manually by opening the flap at the front and throwing in a box of potatoes or it can be filled automatically from the collection bin behind the stone separator. Or in the case of the peeler, it is automatically filled by the reading conveyor.

The washer has been developed to peel or wash a sample of potatoes weighing up to 40 kg. After starting the machine, the bottom, which consists of a peeling disc or wax disc, starts to rotate. The potatoes will be thrown around in the drum and at the peeler, the skin will be sanded off by the rough peeling disc. In the washer, the dirt is rinsed from the potato by means of rinsing during rotation. After a set time, the washer/peeler will eject the potatoes onto the conveyor belt by means of the ejection flap.

Roller sorter

The roller sorter ensures that there is a separation between the potatoes with a diameter of 0-40mm and everything that falls above it. The roller sorter consists of driven rollers whose mutual distance is constantly increased. As a result, the potatoes are transported and the smaller potatoes fall through the opening between the rollers.

The smaller potatoes fall into a weighing bin, are weighed, and then unloaded in a box below. The larger potatoes will be transported further by means of a dosing belt. This dosing belt ensures that the potatoes are spread better on a dosing vibrator. The function of the vibrator is to singulate the potatoes. This is necessary to get a better result in the length measurement that takes place afterward.

Reading tape

After the roller sorter, the potatoes fall onto the inspection belt, where the inspector can view the potatoes and indicate on the corresponding buttons what quality the badge contains. This may include odor deviation, color deviation, etc.

Salt bath

After the potatoes have been peeled, they are transported through a conveyor belt into the salt bath. The salt bath is a bath filled with water containing a certain amount of salt. The potatoes will fall into the salt bath and be transported out of the salt bath by means of the conveyor belt which rotates at the bottom of the salt bath.

The potatoes that are going to float will, by means of flow caused by a pump, hit a force plate which forces the floats to get onto the right side of the conveyor belt. Meanwhile, the good potatoes that sink will end up on the left side of the conveyor belt that turns the potatoes out of the salt bath.

The floats have 3 options which are created by the selector valve. The selector valve can be closed: a kind of intermediate bunker is created where the potatoes are stored. The selector valve can be open at the front: the potatoes fall into the 2nd salt bath with different salt content. The selector valve can be open at the rear: The potatoes continue on the conveyor belt in the continuation of the taring line.

Underwater weigher

The salt bath transports the potatoes to a conveyor belt which transports the potatoes in the basket of the underwater weigher. The conveyor belt will stop turning when all the potatoes are in the basket. The basket of the underwater weigher hangs from a weighing platform, which can weigh the weight of the mass of potatoes. This happens first above water, then the cylinder, which is attached to the basket, will go out and the basket will sink underwater and the weight will be determined again. Based on these two values, an underwater weight will be released. This weight will be visible on the screen and its data will be saved. After the cycle, the basket will automatically unload into the feed conveyor behind the underwater weigher.

Sorter

The elevator conveyor transports the potatoes to the sorter. The sorter consists of a frame with plastic grids in it. The plastic grids start with small square holes and end with large square holes. This frame is attached to the mainframe with shaker arms. By a connecting rod that is attached to an eccentric mechanism, a shaking-shock movement is made with the grids on which the potatoes are placed. Due to the shaking / shaking, a continuous movement is created and the potatoes will be sorted by size because they only fall through the grid where they can pass through.

A conveyor belt is attached under each grid which collects the potatoes per size measure and transports them further to the weighing system.

Weighing system

The weighing system consists of a sturdy frame in which weighing buckets are attached. The weigh buckets are attached to load cells that register the weight in the weight bucket. The weigh buckets are placed under each conveyor that comes from under the sorter. In this way, the weight of each size of potato is determined and these data are immediately forwarded.

The weighing buckets are equipped with 2 valves that can be opened and closed pneumatically. With this, it can be determined whether the potatoes end up on one conveyor belt or the other conveyor belt. The double conveyor belt under the weighing system transports the potatoes via an elevator belt to a discharge box or via an elevator belt further to the inspection room.

Length meter

The potatoes end up in the inspection area from the weighing system by means of the conveyor belt and cross belt. Here the potatoes are first transported over a vibrating chute, this vibrating chute ensures that the potatoes are singled out. Singling the potatoes is necessary to be able to determine the length of the potatoes properly.

The length meter behind the vibrator consists of a conveyor belt that feeds the potatoes under the 3D sensor. This sensor scans the potatoes by means of a laser beam. As a result, every potato can be imaged and the exact length will be measured and stored.

Inspection table

After the length meter, the potatoes end up on the inspection table. The inspection table consists of two conveyor belts so that two sides can be inspected separately. Therefore a selector valve is provided after the length meter. For example, it is possible to choose when which potatoes end up on which conveyor from the inspection table.

In the center of the inspection table, there are trays on a frame to place the different potatoes that contain deviations. The conveyor belts can be controlled separately so that the potatoes can be discharged in the underlying conveyor belt which transports the inspected potatoes to a box outside the inspection room.

Fry cutter

In addition to removing the potatoes after the inspection table, there is also the option of cutting fries. For a number of tests in the inspection room, it is necessary to cut fries from the center of the potato. This can be done with the help of the fry cutter. This machine has a turntable on which the potatoes can be placed in a compartment. The disc rotates along with the cutting mechanism where fries are cut from the potato with a square cutting knife. These fries are collected in a fry basket.

The total installation consists of: