Length Graders

Specific models suited to your application

One of the physical separations available is the separation of foreign material which has a different length than your desired product. Cereal shaped commodities such as wheat, durum and rice have a length which is different that the width or thickness. For applications where a length separation is required an Indented Cylinder or “Trier” is often used.

Premier by ArrowCorp
Principals of operation

Length separation can be achieved using an indent machine or separator.  The indent separator has become a standard in grain and seed processing industries due to their higher capacities and low costs. When looking at the indented cylinder cross section example from the discharge end, the rotation is usually counter clockwise. The Premier Modular cylinder is about 85″ long with an approximate diameter of 23″.  Running through the center of the cylinder is a catch trough and screw conveyor. 

The size of the indents in the cylinder determines the length of the material that will fit inside.  Indent sizes are given in a numerical value and are stamped on the outside of each cylinder on the intake end usually near the long seam. The higher the numerical value, the larger the indent or pocket size.  Indent sizes start from a 2.5 (1MM) up to a #64 (25.4mm) pocket.  Numerical designations usually correspond to 64’s of an inch. (I.E. # 19 = 19/64 DIA.)

Indented cylinders are designed to lift material the size of the pocket and smaller. The rotation of the cylinder causes the material that fits inside the pocket to be lifted up by centrifugal force until gravity takes over and causes the lifted product to drop into the central trough.  The angle of the trough can be changed to catch more or less of the lifted product called “liftings”.  Material that is not lifted and continues through the machine will discharge out of the “tailings” spout. Material at this point is kept separate thus providing two length separations.

The trough position will determine the amount of ‘liftings’ from each of the twenty five cylinders. Each trough control is equipped with a thumb screw lock located on the top of the worn gear cap. The lock should be loosened before trough adjustment and then retightened to prevent the trough from moving by cylinder rotation.

Trough Control
Trough Control

Trough location is indicated with a pointer and a numbered gauge. The pointer indicates the lifting or forward edge of the trough. The lower the number the higher the amount of liftings picked up and conveyed within the trough to discharge. Sample ports on the lifting spouts allow the operator to check the level of the liftings in the product and then adjust the trough to a higher number for less lifting (shorter), or a lower number for more lifted (longer) product.

All cylinder troughs are equipped with grain line blades that aid in conveying the ‘Tailing’ product toward the discharge end. ‘Tailings’ is product which remains in the cylinder and is not picked up into the trough. Tailings are the longer material of the incoming product stream. An adjustable dam or ‘Retarder’ is placed near the tailing product discharge. This enables the operator to adjust the depth of the product kidney in the bottom of the cylinder. As the operator raises the retarder, it increases the size and depth of the product remaining in the cylinder. 

Cylinder separators are most accurate with a product kidney present, which keeps the indent pockets searching for the proper length material. If a cylinder is starved, (little or no discharge in the tailings) there is a tendency for the pockets to lift longer than desired product.

Premier Has a Model Suited To Your Application

Premier have developed specific models suited to your application.

The whole Premier Indent Length Separator line is modular. This allows for the addition of additional Cylinder units to the suit the capacity demands of the application. Standard Premier Units are equipped with 23” x 85” pocketed cylinders, but 17” cylinder units are also available in facilities where head room is restricted. Modular units incorporate features which aid in future overhaul and repair. Cylinders can be removed from either the feed or discharge ends, support rods are incorporated into the frame design to aid removal and reinstallation. Cast Iron is used in high volume product contact areas, with optional ceramic tile available in sheet metal spouts for applications processing high wear commodities.

Premier Modular Indent Length Separators

Modular units can be equipped with individual drives for each cylinder or gang driven with a Poly Chain arrangement.

Premier 2-Hi unit with individual drives on each cylinder. VFD controls for each cylinder allow the operator to fine tune the separation with an infinite range of cylinder speeds.

Premier 25 Cylinder Modular Indent with Poly Chain Drive Arrangement. Cylinder speed is normally not changed with the poly-chain drive arrangements. This is a typical Inland Terminal or Ocean Port equipment requirement.

The “Premier Rice Special” was developed with key Rice Processors to address some concerns they had about this key piece of equipment which is required to remove broken “Brewers Rice” from Head Rice. Over 18 improvements were made to the conventional Premier Modular Units to specialize this machine to their application

 (Photo Courtesy of Sun West Milling)

Nickel Plated Split Cylinders to fight the build up of oil within the indent pockets. Improved felt seals on the inlet and discharge to prevent the loss of polished rice that falls to the floor. Improved operator controls and product flows to maximize capacity on a smaller number of Indent units are just a small indication of all the work Premier has done to improve this key piece of equipment.

Nickel Plated Split Cylinders
Nickel Plated Split Cylinders
Mercury Logo

The Premier Mercury is a new Patented Indent Length Grader Machine ideally suited to customers who require the removal of the indented cylinder on a regular basis, either to change indent pocket size or to clean up between seed lots or to regularly clean the cylinder due to an oil build-up. 

During the 100+ year history of the Indented Cylinder or Trier, the greatest drawback of the equipment was the time it takes to remove and replace the cylinder element. As well the indent length separator was difficult to clean out between seed lots and could become a source of contamination. Several manufacturers (Premier included) had developed split cylinders to aid removal, but even with these improvements, it required 45 minutes to one hour to remove and replace a cylinder element. 

The Mercury can facilitate the removal and replacement of the cylinder element with one person and no tools in less than three minutes. This is a considerable advantage to processors where production and cleanliness is important to their reputation.

The Premier Mercury is also based on the modular concept, and allows for an endless combination of product flows, yet all cylinders can be removed from the same end of the machine.

Premier Mercury Indent Separator

The operator simply opens the door, extends the cylinder support mechanisms and rolls the cylinder out and the replacement back in. No tools are required and one person can easily remove and replace the cylinder in less than three minutes.

Premier Mercury Indent Separator

The Mercury has a modular design, allowing many different configurations to suit the application.

Premier Mercury Indent Separator
Premier Mercury Indent Separator

Premier/ArrowCorp OEM Replacement Components

Premier and ArrowCorp can provide most common wearing parts and components including castings, sheet metal and assemblies on competitive machine and carry a large inventory of parts and components in Winnipeg and Saltcoats, Canada, plus Minneapolis, USA.

Premier manufacture most North American style replacement cylinders, including Carter Day, Ideal, Crippen and Northland Superior style machines. All Premier replacement cylinders meet or exceed the original OEM standards and are individual stamped with the pocket size, serial number and Rockwell Hardness. All Cylinders are manufactured at Premier’s Modern facility located in NewBrighton, Minnesota, USA.

Premier is the largest North American Manufacturer of Indented Cylinders. As well, ArrowCorp/Premier can provide complete cylinder assembly and overhaul parts packages for the Carter-Day Uniflow, #3 and Modular Carter Indent Cylinder machines, as well as the Northland Superior, Crippen Northland and Ideal Indent Cylinder Machines.

OEM Replacement Components
OEM Replacement Components
OEM Replacement Components

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