Our continuous solutions..
By focusing on solely three parts of the entire (food) production process, Sobatech became a worldwide specialist in designing, manufacturing and commissioning equipment for the continuous dosing, continuous mixing and bulk fermenting of (food) products. With its focus on three parts of the entire food production chain, Sobatech became a worldwide specialist in designing, manufacturing and commissioning equipment for:
- CONTINUOUS DOSING OF INGREDIENTS
- CONTINUOUS MIXING AND KNEADING
- CONTINUOUS BULK FERMENTING
The Sobatech continuous dough mixing systems are characterized by constantly delivering a consistent product quality. It has the ability to apply exceptional high shear forces during kneading. These points of differentiation are vital to many industries where energy has to be applied to raw materials in order to get a consistent food quality. The continuous dough production process starts at the dosing of the separate ingredients (continuous dosing). After that, energy is applied to the ingredients in order to equally distribute them over the complete mass (continuous kneading). Finally, Sobatech’s continuous bulk fermenter allows the dough to rest and develop taste, aroma and consistency (continuous bulk fermentation).
Continuous dosing is essential for reaching the required product quality. If the various raw materials are not dispensed in the correct quantities to begin with, it will never be possible to produce a correct product. For that reason, the dosing of all solid & liquid ingredients is constantly monitored: the line stops and gives an alarm signal if a dosage (process value) deviates from the set value (the time and % of the deviation are adjustable).
VOLUMETRIC VS. GRAVIMETRIC
When we look at the continuous dosing of the solid ingredients – the division can be made to either dose them volumetrically or gravimetrically.
A volumetric dosing system doses a given volume of material per time unit. The dosing speed of a volumetric feeder should be selected manually, which may vary based on the nature of the raw material input. A volumetric feeder is open-loop in a sense that it does not corrects to variations in the material’s density.
A gravimetric dosing system doses the actual given weight of material per time unit. The weight is measured by using load cells which form the foundation of the entire system. In the self-calibrating gravimetric feeder system, the motor automatically alters its speed when a change is detected in the material flow. This eliminates the need for manual adjustment, which ís required when using a volumetric feeder. Such a change in material flow can for instance be the result of the addition of new material or fluctuations in the material density. This means that, when using a gravimetric feeder to dose, you are in complete control of the quality of your final product.
LOSS-IN-WEIGHT VS. GAIN-IN-WEIGHT
Sobatech works with so called loss-in-weight feeders which are gravimetric feeders and measure the weight reduction per time unit. Sobatech’s dosing systems ensure an accurate flow of ingredients during both loss-in-weight (normal operation) as well as gain-in-weight (during refilling). The dosing systems are located on digital load cells that constantly measure the weight reduction. Based on that information, the speed of the dosing screws is being controlled. As Sobatech’s software system measures the flow of ingredients multiple times per second, adjustments are made instantly. Generally, Sobatech’s system seperate the major from the minor ingredients and therefore offers two dosing systems for the powders:
GRAVIMETRIC WEIGHING BELT
On a gravimatric weighing belt, the speed of the belt x the flour weight on the belt = the amount of flour that is being dosed
FLAT BOTTOM DOSING HOPPER
On the flat bottom dosing hopper, the weight reduction per time unit is the base for controlling the speed of the dosing screws. The design of the flat bottom feeder ensures there is no compression on the dosing screws during refilling.
OPEN SOURCE SOFTWARE
Sobatech developed its own tailor made open source software to control the feeder-pumps and other hardware involved in the continuous dosing of the ingredients. This means that in Sobatech’s continuous mixing systems, there are no hidden programs nor protected passwords; everything can be open and accessible to the customer.
Sobatech’s software to control the feeder pump and other dosing hardware ensures a continuous and accurate flow of both dry ingredients as well as liquid ingredients of low, middle & high viscosity. Measurement equipment such as magnetic and Coriolis flow meters are used to regulate the correct quantity of liquid ingredients entering the continuous mixer. Sobatech can either tap the liquids from a circulating pipeline or from a dosing tank.
A continuous mixing system by Sobatech uses a 2-phase process for mixing the ingredients into a consistent and homogeneous mass. As soon as all ingredients are evenly and accurately distributed over the complete mass (phase 1), the development takes place (phase 2). This is done in a controlled and extremely precise way during kneading. Production volumes range from 50 kg/hour to over 10,000 kg/hour. This can be accomplished in an almost employee free operational environment resulting in significant (labor) cost savings.
PHASE 1 MIXING: THE HOMOGENIZER
Both phase 1 mixing (the homogenizer) and phase 2 mixing (the continuous kneader) are based on the first-in / first-out principle. After dosing the solid ingredients, they pass through the homogenizer phase. In this phase the powders are, by means of medium pressure, injected by the liquid ingredients. The liquids enter the homogenizer in a pre-defined order. This non-mechanical way of blending the ingredients is what we call the first phase of mixing. The homogenizer phase guarantees a high level of water absorption and therefore more moisture in the final product.
Blending minor ingredients through a batch of about 100 kg is much more challenging than blending it through a 1kg mass (going through the Sobatech homogenizer).
PHASE 2 MIXING: THE KNEADER
The innovative tools of the continuous dough mixer (phase 2 mixing), are responsible for the controlled flow of mass throughout the mixer. The combination of a relative small amount of mass in the mixing chamber with a relatively high volume of tooling, result in a remarkable high energy efficiency. A large part of the energy developed by the mixer tooling is put into the mass.
The continuous mixing tools handle the raw materials gently and efficiently. Sensitive ingredients such as fruit, flakes or similar elements can be introduced without degrading. Consequently, the continuous mixer can handle a wide variety of applications such as fine solids, cereals, meringue masses, muesli etc. so that it delivers nearly all fresh or extended-shelf-life baked goods.
The Sobatech continuous mixing system is a closed system. This means that there is no pollution from outside of the machine, making it easier to deal with ATEX rules. Cleaning the dough mixer area is also much easier because there is less dust in the machine area.
There are double safety switches mounted in the top covers to ensure that the tools stop turning immediately after opening. Also, a signal is given to the PLC so that part of the line stops normally. Lastly, a sound signal goes off to warn the operator.
LESS ENERGY LOSS
Sobatech’s continuous mixing system is able to carry out the mixing process in defined and controlled steps. The excellent mixing and kneading characteristics of the second stage ensures perfectly controlled energy input into the dough. This means there is less energy loss in a continuous dough mixer compared to a batch mixer. The “time to peak” point is reached faster.
CLEANING IN PLACE (CIP)
Sobatech continuous mixing systems can be equipped with an automatic cleaning in place system.
CONTINUOUS BULK FERMENTATION
The preparation of many foods require a resting time for the development of taste, consistency, aroma etc. Time is a key factor within this continuous bulk fermentation process. Besides time, also ensuring each part of the mass is exposed to the same environmental conditions is of great importance in end-product quality and consistency.
TEMPERATURE, TIME & HUMIDITY CONTROLLED
At the outlet of the continuous mixer, there is a vertical belt to bring the dough into the continuous bulk fermenter tube. The fermentation time can be controlled by adjusting the screw speed in that tube. The set point of the speed is included in the final recipe. At the output of the tube, there is a divider that takes out the dough. The tube has a double jacket to stabilize the dough temperature. It is also possible to control the humidity in the tube. Combining time with an equal and controlled exposure to the right proofing conditions are the vital features of a Sobatech continuous bulk fermenter. Sobatech’s system control software allows to easily monitor and modify the temperature, humidity and speed of the continuous fermenter.