Özgür ACAR , Yemmak Makina Sanayi ve Ticaret A.Ş. : Feed factories are sort of establishment where raw materials brought into the factory, are turned into feed processed and packed without human intervention in different production processes. Automation is the most important element which increases efficiency of this production made without human intervention and ensuring the stabilization of system.
We can handle and review the production line of feed factories as raw material intake, dosing, grinding & mixing, pelleting and packaging sections.
RAW MATERIAL INTAKE PROCESS
In a feed factory, production starts by receiving raw materials. In raw material receiving, process starts with the entrance of truck bringing raw materials into the factory. Within this process, samples are taken according to the type of raw materials brought to the facility and these samples are passed through quality control in a laboratory. Therefore, compliance of raw materials in standards is controlled. Then, raw materials which are in compliance with the standards are unloaded by hydraulic lifts into the intake bunkers. During this process, potential dusting is absorbed by aspiration fans and regained by cyclone. Then, raw materials are carried into relevant silos through transporting equipment.
Raw materials pass through the magnet while being carried. Possible metal particles in raw materials are separated here. Magnets may be in various types and features such as single and multiple layers. In addition, raw materials are separated from foreign particules such as thread, paper, nylon etc. by being passed through waste sieve before being transferred to relevant silo. Raw materials brought into the factory are stored in storage systems which have different properties in various places. Liquid additives such as oil, molasses are stocked in tanks. Some raw materials are stored in flat storages, and some of them are stored in concrete or steel silos. This may vary depending on structure, capacity and functioning of factories. Raw materials stocked at high capacity are stored in raw materials steel silos. Capacity of horizontal and steel silos may vary depending on the density of raw materials.
Raw Material Intake Automation
Firstly, quality control analysis of raw materials in laboratory.
After quality control process is completed, raw materials are transferred into the relevant silos.
Dosing is the operation where main raw materials such as particle feeds, oil seed pulps, milling by-products which consist the majority part of total dosage used in feed production are dosed in. Dosing process is done in the main dosage bunker located on a central point under the raw material silo through screws straggling back from each silo according to relevant formulation.
Macro Dosage: It is the unit where macro level additives (salt, marble powder, DCP etc.) to be dosed more accurate since usage in feed and mixture participation rates are less than the main dosage materials.
Micro Dosage: It is the dosing unit where weighing which participates in feed processing at micron level is the most sensitive. It is the unit where premixes such as vitamins and minerals are dosed in.
Recipe is determined according to desired ration, and manufacturing plan is created. According to determined manufacturing plan, main dosage, premix and liquid additives are mixed depending on contents of prescription. To ensure that mixture elements are received at accurate rates, elements are carried onto the scales located under the dosing unit from silos through transport equipment speeds of which are adjusted, thus amount failures are minimalized.
All stages of the dosing process are recorded and stock and production information are reported in details. Brill file format integration is also available in order to give information from rations directly to the mixing program. Production reports are integrated into the ERP systems and production department is connected to the other departments of the factory.
GRINDING & MIXING PROCESS
Grinding: After dosing process in feed formulation is completed, raw materials weighed in the main dosage are carried into the rotary sieve through over the mill transporting equipment and sieved here. The reason why raw materials are sieved is that particles are sent to the dump-bunker of mill without milling needed. Thus, both electricity saving is ensured, and nutrition loss arising from high temperature depending on high circulation in the mill is reduced. Large particles combine with the other sieved part in the lower bunker of mill after being broken with suitable sieve in hammer mill.
Mixing: While grinding process continues, feeding units on the mill adjust amount according to the cycle of the mill. Thus, weighing and breaking processes for that batch are completed. Then, mixing process is started. The most sensitive point to be paid attention to and the most important stage in feed factories, is the mixing process. Density of mixture varies since each formulation has a different content. Feed with different density has a diverse mixture time in the mixer. This time varies depending on type and capacity of the mixer.
Grinding & Mixing Automation
General operation principle of the system is to ensure maximum performance in minimum period by keeping the current of mill between aimed lower and upper current values. Program increases and decreases cycle of feed engine according to read current value.
Inverter speed starts with entered value for operating speed first. Then, there is no change in the inverter speed if current of the mill is between lower and upper current limits. If current of the mill is higher than the upper current limit, the inverter speed decreases. If cover of the silo is not closed and current of the mill is lower than the lower current limit, the inverter accelerates.
Mixing times of the mixer can be adjusted from the system, mixing process continues until determined time limit ends. Needed liquids are added to feed at this point of process through dosing system.
Feeds to be in pellet form are carried into the dust silos in the pellet press after grinding process is completed and liquid additives are added. Pellet press line consists of three section as feeding, conditioning and pressing. Pellet disc at required size is mounted on the pellet press machine for relevant feed.
Water steam is highly important in pellet formation. Pellet quality depends on the steam quality. Pellet press is a machine which allows dust feed to be mixed with steam, mechanically pressed through disc and roll and produced in different diameters.
In our machines, have automatic roll adjustment specification that gains to system easy maintenance operation. In addition, this specification is effected on pelletizing time.
Press machinery can be locally controlled or operated in process automation. Automation regulates steam valve and feeder speed and reaches the machine to the target values within the shortest time without blocking it. It can be adapted to engines with different powers through current calibration.
It is possible to use automatically and manually depending on values of current, steam and temperature. Graphics and reports of current and temperature trend, capacity and efficiency reports and automation shows the efficiency of the machine.
Fine, pellet and granule feeds manufactured are weighed on bagging scales and packed after being dispatched to product silos, then stitched bags are sent by being loaded to trucks through conveyors. Bagging scales are machinery which weigh sensitively for packaging of dust feed or pellet feed in bags of 20-50 kg. They are manufactured as load cell and electronic control system.
Packaging lines have local screens in the process and operate with operators in charge of related machine. Parameters of the machine varies depending on separate operation prescriptions according to the product type. Scale feed speeds for fast and sensitive weighing have three modes as fast, medium-fast and slow. Feed speed adjustments vary depending on the product type. Product reporting is made by comparing raw materials sent to the system and number of bags coming out of the scale.
Automation equipment consist of various hardware and software. These hardware and software may vary depending on preferences and requests of technology companies and feed factories. Therefore, we preferred to explain the subject over hardware and software that we use or prefer as Yemmak.
PLC: Tracking the system equipment fast is highly important in process automation. Therefore, we prefer Mitsubishi Electric PLC. Because Mitsubishi Electric CC-link responses the needs of communication protocol and process automation.
PC: We use 2 programs in process automation. One of these programs is scada that controls the whole flow and the other program is blending program that controls the dosing system and the reports.
HMI: There are operator-machinery interfaces that operators use at pellet presses and packaging machinery.
Frequency Inverters: Thanks to frequency inverters, we can control equipments in the processes sensitively. At this point, we prefer Mitsubishi Electric brand since it has CC-link communication support.
Weighing Indicators: They are used to transmit weight information to the automation.
Energy Analyzers: They are used to transmit energy consumptions in the processes to the automation, so energy consumption in the processes can be reported.
Scada: There is flow diagram on the PC screen. Operation status of all machinery and equipment is monitored through this flow diagram on the PC screen. All machinery and equipment are operated through START-STOP buttons on the PC screen. Equipment of the system change colors according to status as gray during stop, green during operation and red during error. Parameters of equipment and machinery are reviewed through set values page. For example; mixing, parameters of mil units, min/max operational values…
Current and circulation values of elevators can transiently be monitored, and recorded for previous reporting. In addition, failures in instruments within the factory can be reported.
Mixing Program: For all dosing scales within the system, digital indicators are used, and load-cell is preferred according to the scale capacity. Automatic dosing program programmed according to the properties of the system automatically ensures operation of dosing scales through computers in accordance with the prescription entered in line with the properties of feed to be produced, and reporting.
Mixing control system controls weighing equipment in dosing units and prepares reports (Main dosage, liquid dosage, micro dosage and macro dosage).
With Yemmak IQ mobile application, you will be able to control process automation of your feed mill by monitoring over mobile phone, tablet or computer, and report all process. Allowing you to take the decisions to increase production efficiency in any place, at any time, and to control your factory.
Errors of equipment are listed, and continue to be listed until the problem is solved and confirmation is received by the operator. Production details (batch, code, prescription etc.), raw material usage reports can be monitored. Current and voltage values of engines can transiently be monitored, and reports of previous periods can be received.
Yemmak IQ mobile application is available on Windows Store, App Store and Play Store for your experiment.
We also suggest you to read our previous article titled "Process Control and Automation in Feed Plants".