Mixing operation is required in various sectors of the processing industry. This mainly includes the chemical and pharmaceutical industries and mineral oil industry, besides many other areas. This can be in the production of finished products or in the processing of additives or auxiliary materials. The common base of the process is the requirement that mixing is carried out using a defined recipe with high accuracy. Any nonconformity from the defined recipe has a direct impact on the product’s quality, as well as the efficiency of the manufacturing process.
Thus, compliance with the specifications is key to resource-efficient operation. Furthermore, the fluids encountered are extremely diverse. It ranges from liquid additives, water and concentrates, to oil, paint, paraffin, varnish, as well as components for varnish manufacture or a variety of viscous fluids. In the mixing procedure, distinction is made between quasicontinuous processes or batch-oriented processes. Choice of the suitable technique depends on the reason behind the mixing procedure and further processing of the product. However, the mixing and reaction features are of great significance here as well.
Solution
The automation solution for mixing applications by ABB comprises of a flowmeter and the AC500-eCo small control system, together with the BatchControl software solution adapted to the mixing process.
Choosing the measuring principle for the flow rate is fundamentally dependent on the fluid’s characteristics. Electromagnetic flowmeters are ideal for conductive fluids. The standard devices with flanged connection belong to the ProcessMaster series, while the devices for hygienic applications are from the HygienicMaster series. Certainly, fluids with low electrical conductivity or other key features can also be mixed; such as beverage concentrates and fruit juice with high Brix concentrations, fluids with high alcohol content, very fatty or oily fluids, and fluids that form conductive or insulating thin film.
In relation to high viscosity, transmission is done in heated piping. In part, these types of fluids are expensive, so it is sensible from an economic point of view to process the required quantities in as close compliance as possible with the recipe.
Coriolis mass flowmeters are particularly well-matched for this. The CoriolisMaster type FCB100 is used in the basic version. The CoriolisMaster type FCH100 is well-suited for hygienic applications. It consists of hygienic connectors, has electropolished meter tubes and is EHEDG certified. It can thus be employed in any process in the food sector. The CoriolisMaster is linked to the small control system via Modbus communication. Any required switch outputs or inputs are conducted through the controller. The measured values necessary for the mix are read from the Coriolis flowmeter by the controller directly via the Modbus. With regards to electromagnetic measurement techniques, high resolution pulse outputs are used for flow transfer.
Batch Mixing Process
During the mixing procedure of a batch, two types of applications are noticed: those with nonstop extraction from the mixing tank during mixing and those with extraction after the whole mixing operation is finished. Both batch process variants can be performed using suitable mixing programs.
Continuous Extraction During the Mixing Operation
The operator enters the total mixing amount and the number of individual steps using the touchscreen display. Afterwards, the mixing operation is started through a contact or on the display. The pumps and valves are then automatically started by the control system’s BatchControl software. The installation stops automatically after the whole mixing operation is finished.
Extraction after the Mixing Operation is Complete
In this variant, only the total mixing amount needs to be entered by the operator. All the other steps then start automatically. Regardless of which variant is chosen, the mixing proportion is entered directly by the operator before mixing is underway. Extra possibilities include entering the data in a password-protected area or transferring from a higher-level system via a communication link.
The mixing valve can be started in a single step, as well as in two steps with a pre-contact. Two-step activation allows for slower incorporation of a recipe component at the end.
The overrun correction performed in the control system improves mixing precision. The parameters for the correction can be tuned by the operator. A rapid shut-off valve with repeatable closing times is required for the mixing system. The valve has to be supplied by the customer, and is not included in the ABB scope of delivery. Certainly, the system can also be used for volumetric mixing based on the Coriolis mass flowmeter. In the process, the density recorded by the measuring device is used for calculation purposes. An operator screen has been configured in the control system as a commissioning monitor for the parameterization of the Coriolis mass flowmeter. The device is parameterized beyond the basic mixing operation. The controller also monitors numerous device messages and alarm parameters that allow interruption of the mixing operation if a serious situation occurs, thus preventing damage because of improper mixing.
Component Configuration
Mixing can be completed using different installation layouts. Two types are given below.
Mixing from Two Components with Central Pumping
The fluids to be mixed are transferred from two buffer tanks using a pump.
The valves on the pump and the tank outlets are operated by the controller. The mixing operation as well as the recipe accuracy is achieved through the mixing valve behind the flowmeter.
Figure 1. Example of mixing from two components.
(1) Buffer tank (2) Buffer tank shut-off valve (3) Feed pump (4) CoriolisMaster flowmeter (5) Modbus connection to controller (6) Small control system with BatchControl program (7) Mixing shut-off valve (8) Mixing tank
Mixing from Several Tanks Using In-House Feed Pumps
This variant can also be executed using the system. The mixing operation and initiation of the components is performed automatically. The number of contacts and signal outputs of the control system are suitably modified.
The combination of a variety of measuring devices, as well as various types of flowmeters is also possible. This makes sense if, for instance, miniature quantities have to be dosed. Based on the choice of measuring device, connection to the control system is also made through impulse signals or the Modbus. Extra individual variants are conceivable and can be implemented depending on the project.
Figure 2. Example of mixing from several components.
(1) Buffer tank (2) Buffer tank shut-off valve (3) Feed pumps (4) CoriolisMaster flowmeter (5) Modbus connection to controller (6) Small control system with BatchControl program (7) Mixing shut-off valve (8) Mixing tank
Operator Interface Views
The BatchControl solution is operated via a touchscreen display. Entries are made in views grouped according to operation.
Password protection is provided to safeguard against unintended entries. As an extra option, the prospect of saving process data on SD cards is possible. For further analysis and documentation of the process quality, the data saved in csv format can be evaluated.
Figure 3. Operator screens for entering set point and recipe when mixing two components with continuous extraction from the mixing tank.
Figure 4. Operator screens for entering set point and recipe for the batch mixing process.
Graphic presentation of measured values for density, flow rate and temperature for the Coriolis mass flowmeter over time.
Figure 5. Trend monitor operator screen.
Additional views for device status of the CoriolisMaster, as well as parametrization possibilities complete the functionality.
Customer Benefit
Automating the mixing operations using the ABB system solution offers a range of benefits to the user. Personal monitoring of the processes will not be needed anymore. The system is totally self-sufficient. This allows for substantial improvement of process efficiency. Product quality is improved owing to precise compliance with mix proportions. Simultaneously, raw material waste is reduced to a minimum. This is achieved through the application of measuring devices with high precision of up to 0.1% with regard to flow rate. By doing so, recipe accuracies in volume mixes of better than 0.02 l were accomplished using a device with DN 25 nominal diameter.
Also, by using the Coriolis mass flowmeter as a measuring device, measurement inaccuracies because of air pockets in the mix of mass percentages are disregarded. Moreover, the special form of the meter tube in the CoriolisMaster provides lower pressure loss when compared to other device types. This also enables the mixing of thick and high-viscosity fluids.
The standardization of the system components and easy implementation of individual programming provide many advantages. Implementation based on a small control system allows for economical adaptation to specific requirements and thus easy integration with current production processes. This also applies to the easy implementation of connection to higher-level systems.
Even during operation, the system features smart use and easy handling. Function-specific views on the display give the operator a quick and clear overview. Optionally, recording of individual batches can be combined into the controller system. The mixing process data is in table form as a csv file and offers a foundation for numerous process assessments. Other than business-related tasks, the system can also be used for process optimization, quality assurance or traceable documentation of product quality.
Product Information
Coriolis mass flowmeter CoriolisMaster FCB100 |
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Coriolis mass flowmeter CoriolisMaster FCB130 / FCB150
— Nominal diameter: DN 15 to DN 150, adapted to the required flow rate
— Process connection: flange according to DIN 2501 / EN 1092
— Material used for sensor: stainless steel 1.4404
— Measuring accuracy for mass flow: up to 0.1%
— Permissible measuring medium temperature: -50 … 205 °C
— Outputs: Modbus RTU, 2 additional configurable digital outputs
— Power supply: 24 V DC |
Coriolis mass flowmeter CoriolisMaster FCH100 for hygienic applications |
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Coriolis mass flowmeter CoriolisMaster FCH130 / FCH150
— Nominal diameter: DN 25 to DN 80, adapted to the required flow rate
— Process connection: pipe fitting in accordance with DIN 11851
— Sensor material: stainless steel 1.4404 or 1.4435, polished, in accordance with EHEDG and FDA
— Measuring accuracy for mass flow: up to 0.1%
— Permissible measuring medium temperature: -50 … 205 °C
— Outputs: Modbus RTU, 2 additional configurable digital outputs
— Power supply: 24 V DC |
Electromagnetic flowmeter ProcessMaster FEP300 for conductive fluids |
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Electromagnetic flowmeter ProcessMaster FEP300
— Nominal diameter: DN 3 to DN 2000, adapted to the required flow rate
— Process connection: flange according to DIN 2501 / EN 1092
— Liner and electrodes: selection according to medium
— Measuring accuracy: up to 0.2%
— Outputs: 4 ... 20 mA, Impulse, Status
— Power supply: 24 V DC, 230 V AC
— ABB universal measurement technology operating concept |
Electromagnetic flowmeter HygienicMaster FEH300 for hygienic applications |
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Electromagnetic flowmeter HygienicMaster FEH300
— Nominal diameter: DN 3 to DN 100, adapted to the required flow rate
— Variable process connections: pipe fitting according to DIN 11851, welded spud and other
— Liner: PFA
— Electrodes: stainless steel, 1.4539
— EHEDG and FDA compliant
— Measuring accuracy: up to 0.2%
— Outputs: 4 ... 20 mA, Impulse, Status
— Power supply: 24 V DC, 230 V AC
— ABB universal measurement technology operating concept |
Batch controller AC500-eCo PM554-TP |
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Compact controller AC500-eCo
— Inputs: 8 binary inputs
— Outputs: 6 binary outputs as transistor outputs
— Load capacity of transistor output: 24 V DC, 0.5 A, maximum 5 W
— Communications interface to mass flowmeter: Modbus RTU
— Program memory: 128 kByte, with special software for fill operations |
TFT operating panel CP620 |
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Control panel with touchscreen, screen size 4.3" or larger
— Display screen: TFT Color / LED
— User flash memory: 128 MB
— Serial interfaces: RS-232, RS-485, RS-422
— Ethernet port: 2 x 10 / 100 Mbit/s
— USB port: 1 x version 2.0
— Power supply: 18 ... 30 V DC, 0.4 A (at 24 V) |
This information has been sourced, reviewed and adapted from materials provided by ABB Measurement & Analytics.
For more information on this source, please visit ABB Measurement & Analytics.