Thickness of the pellet press die. Running-in of the pellet press. Operation of the rollers and dies.
Maintaining and Extending the Life of the Matrix.
Using dies and rollers
Selection of parts for granulators
Reducing production costs is relatively simple provided that a few basic rules are met. We encourage you to familiarize yourself with the information contained in this section, because ignoring it will certainly result in losses.
Factors affecting matrix life:
The life of the matrix depends on the following factors:
the design of the matrix and the type of steel from which it was made,
granulation line configuration and production technology,
type of granulated raw material (poultry, pig, cattle feed, sawdust, straw, sugar beet pulp, sprouts, plastics, sewage sludge, garbage, etc.),
the design of the granulator, especially its stiffness and degree of wear,
experience in operating a granulator.
Factors that shorten the life of animal feed matrix
low fat,
a large number of ingredients with a high degree of friction,
no or incorrect parameters of steam dosed to the conditioner,
poorly selected matrix design,
bad service.
Factors that shorten the life of the matrix for biomass and other raw materials
incorrect fragmentation of the raw material,
raw material of heterogeneous species,
a large amount of high friction ingredients (sand, bark, adhesives),
incorrect moisture content of the raw material (too dry or too wet),
poorly selected matrix design,
incorrect operation.
Mechanical factors shortening the life of the matrix
play on the main shaft of the granulator (worn or damaged bearings),
clearances in the die mounting seats (retaining ring in the rotating shaft disc and reinforcing ring),
incorrect setting of the rollers in relation to the matrix – too much pressure and the rollers touch the matrix during operation or too much distance from the matrix,
using used rollers for a new matrix,
using a used matrix for new rollers,
incorrect setting of at least one scraper,
roller adjustment system out of adjustment (or front roller holder not tightened),
poorly selected matrix design for a given medium,
no separation of metal parts and stones.
Extending the life of the matrix
Matrices for feed can work for up to 2500 - 3000 hours. Matrices for pure biomass of forest origin for over 1500 - 1800 hours. Many of our customers achieve similar or better results and you can too, if you meet several conditions.
The order below is random, but neglecting even one condition will shorten the life of the matrix:
Raw material purity
Try to obtain raw material from proven suppliers who care about its purity and therefore quality. If the raw material is stored on an unpaved surface, is not covered, is transported by loaders moving on unpaved roads, the quality of this raw material may be low.
Purity Test
Pour water into a bucket and pour in the raw material. Stir vigorously, repeatedly, at intervals of several dozen seconds. Then carefully remove the raw material, without touching the bottom of the bucket. Now check how much and what impurities are left at the bottom.
Experienced operators
Understanding the principles of processing technology requires time and commitment as well as training and practice. Investing in employees is absolutely essential and, contrary to appearances, is not expensive. Human errors cost much more. Therefore, if you think that your operators require additional knowledge, send them to us for training immediately.
Production process
It is of great importance, because if it is incomplete, the matrix and rollers will require rescue, sooner than you think. The production line must contain devices that will protect the granulator from foreign bodies. These are magnetic separators on tanks, descalers, pneumatic transport systems, magnetic catchers on the hopper of the granulation chamber. Their absence will also damage other machines (e.g. a hammer mill) and may lead to fire or explosion.
Rigidity of the granulator structure
The correct distance between the rollers and the matrix is the thickness of a sheet of paper. It is about 0.1 mm, which is not much. Only granulators with appropriately selected component parameters guarantee the appropriate rigidity of the structure, which will maintain this distance during operation. Thanks to this, the matrix will wear evenly and will last longer.
We encourage you to familiarize yourself with GRP and GRB granulators manufactured by Nawrocki Granulation Technologies. The rigidity of the structure and the selection of solutions tested in difficult conditions guarantee the appropriate service life of the matrix and rollers.
Preservation of the matrix during downtime
In the event of a planned production downtime, the matrix should be preserved with a preservative. This is usually the basic raw material taken from the conditioner with an admixture of about 6% - 10% of any oily substance. To respect the environment, we recommend using vegetable or animal oils that are not suitable for consumption or use by humans or animals.
The preservative mixture added at the end of the production cycle facilitates start-up, minimizes the time needed to achieve efficiency and reduces electricity consumption.
The tank with the mixture should always be located near the granulator. Similarly to the shovel, which the operator manually and in compliance with health and safety regulations pours into the matrix through the door on the hopper of the pelleting chamber cover.
The amount of the preservative mixture depends on the internal diameter of the matrix and the diameter of the holes, e.g. a matrix fi 750.250 requires 50 kg - 100 kg.
Note for feed producers: before pelleting the preservative mixture, the inlet to the cooler should be closed. It must not be allowed to get into the devices behind the pelletizer (cooler, sifter, etc.).
If you have any doubts regarding the operation of the matrix, contact our technologists, who will diagnose the problem and advise what to do.