Northern German company Hasytec has tackled the problem of biocorrosion and developed an efficient solution
Cost efficiency, streamlined process chains and environmental friendliness are just a few factors that have always been of high importance in industry. Deposits and biocorrosion have a negative impact on the operational time and life cycle of storage tanks, pipelines and machines, and thus
strongly influence the design and planning of processes.
AVOIDING BIOFILM &
DEPOSITS THROUGH THE
USE OF ULTRASOUND
Biofilms form predominantly in liquid-bearing systems such as storage tanks, pipelines or cooling towers. Organic and inorganic molecules settle at the so-called interfaces (adsorption). Microorganisms and algae begin to settle. They form a gel film that increases the resistance to external influences. After some time, the film begins to spread over a wide area, and parts of the original base can also detach.
The issue of biofilms and deposits affects almost all industrial sectors, regardless of whether it is shipping, food production or paper manufacturing. Even steel production is affected. The example of a vessel’s hull is a good illustration of what biofilms are capable of. Although the hull is treated with antifouling paints, biofilm still forms and creates the basis for the growth of barnacles, algae and mussels. The cleaning of hulls alone is a significant cost factor for ship owners.
In the case of storage tanks and pipelines carried media can become contaminated. The resulting biomass is capable of clogging filters and pipelines and thus impairing the function of the entire system or rendering it inoperable. More serious, however, is the impact of biocorrosion. Over time this degrades even stainless steels and leads to leaks and pipe ruptures. Maintenance and replacement require additional investment. In some cases, the health of employees is also at risk. In the case of cooling towers, the buzzword is Legionella. If aerosols enter the human body through the respiratory tract, they can lead to illnesses and even pneumonia.
Intelligent Deposit Protection (IDP) is a technology that prevents the formation of organic and inorganic deposits on all liquid-bearing surfaces. In this process transducers are bonded from the outside to the equipment or tank that is to be protected.
A carefully selected two-component epoxy resin adhesive is used for this purpose. Then a special process is used which ensures the correct handling of the adhesive and at the same time prevents the transducers from moving during the curing phase. A patent application is pending for this self-deployed solution. Special high-temperature transducers and adhesives are available for high-temperature applications. The generated ultrasonic signals penetrate the surface and propagate in the guided medium. There the sound waves prevent the adhesion of inorganic and organic deposits. This also prevents biofilm. As a result, biocorrosion is significantly reduced or even completely prevented.
One of the basic factors of the technology is the non-gravitational ultrasound generation, which leads to the possibility of permanent and preventive application. This only affects the deposits and protects the sonicated equipment itself. Other systems are not negatively affected.
PROVEN IN SHIPPING,
OPTIMISED FOR INDUSTRY
At first, the innovative ultrasonic technology was used in the field of industrial shipping. After the system successfully held its own there, industrial use showed up rather by chance. For test purposes the process was installed on a plate heat exchanger and a cooling tower. The results were convincing and for about three years the predecessor system has been used in various branches of industry. In 2020 the company was awarded the German Innovation Prize for this.
Especially at the beginning, a lot of convincing had to be done to get a
foot in the door. Through an intensive exchange with customers and a lot of work, further areas of application could be opened up. A great advantage for the company is that many customer requests and concerns can be further developed into new standard applications. This holds immense potential; many concerns can be transferred across a wide range of industries and not only individual users are looking for solutions.
MEETS INDUSTRY 4.0
IDP has been specially optimised to meet the requirements of industry. The previously used Dynamic Biofilm Protection (DBP) technology was installed, and subsequent adjustments were not possible. The evaluation of parameters or the performance of a fault analysis were also only feasible to a very limited extent. The propagation of the ultrasonic waves depends, among other facts, on the density of the medium, the ambient temperatures, the layer thickness of the transferring material as well as the solid content in the medium itself. This results in very differentiated performance requirements for various liquids, emulsions and products.
The IDP technology, which has now been further developed, autonomously measures the variables mentioned and determines the required frequencies and power from them. Furthermore, it detects deviations from these determined values and makes the necessary adjustments independently and permanently so that the optimum combination of power and frequency is always present. In this way, the system can react to changing filling levels of storage tanks.
In addition, the power of the IDP has been increased by a factor of 3.5 compared to its predecessor and power duration variables have been integrated. Thanks to the newly integrated USB port, future system and software updates can be easily installed via Plug & Play. This allows the system to be expanded with already planned content. In addition, external devices can be connected.
The problem of limited error analysis and result evaluation has also been addressed and revised. Now almost all data can be read and analysed from the modular control unit to the individual sounder. This includes running times, performance analyses and also error messages of individual components. The goal of the adjustments is to ensure that the customer can rely on the system at all times. The extended error analysis of the interface created, the artificial action of the system and the possibility of uploading updates ensure the foundation for Industry 4.0. The system supports the customer in ensuring an optimised, resource-saving and environmentally friendly process cycle; at the same time, IDP increases the production and operational safety of the plants, as well as the expected service life.
IDP requires a permanent power supply in addition to a metallic and liquid-bearing surface. In order to also be able to effectively sonicate plastic pipes, special installation options exist. In general, a distinction is made between process-related applications such as plate heat exchangers, pipelines, storage tanks and cooling applications such as cooling towers, wet separators, evaporative cooling systems. Practical experience shows that by using ultrasonic technology, the addition of biocides to evaporative cooling systems, cooling towers and wet separators can be reduced to a minimum and the corresponding systems can still be operated safely within legal limits and specifications. This makes an important contribution to ensuring production safety. Plate heat exchangers benefit from longer intervals until the next maintenance and cleaning work, as significant service life extensions are made possible. By addressing customers’ problems, the company has been able to develop earlier customer requests, such as the use in pasteurisers and bottle washing machines, into today’s standard applications and to incorporate the knowledge gained in other industries.
Recently IDP was commissioned on storage tanks in cardboard production after the first initial test project has proven very successfully. Instead of almost daily cleaning, the storage tanks now are flushed on a weekly basis only. Another good example is the application in steelworks in Central Europe, where the technology is used to prevent not only biofilm but also the growth of invasive zebra mussels in parts of the cooling system.
Fouling is of increasing economic importance for companies in a wide range of industries. For example, biocorrosion not only reduces the life cycles of liquid-carrying systems and equipment and necessitates the premature replacement of tanks, pipes and coolers. At the same time, operating costs also increase due to the necessary maintenance servicing. An additional, often underestimated cost driver is the decrease in efficiency/underperformance (heat transfer coefficients) of the individual components, which increases the total energy demand of the industrial plant. A factor that should not be neglected is the necessary use of biocides and chemicals, which are reflected in the ecological costs.
The issue of biofouling, deposits and biocorrosion is becoming increasingly important. This is not only due to the ecological aspects, but is much more based on an increasingly detailed consideration of individual processes, interrelationships and resulting outcomes. Small things can have a big effect, in a positive sense.
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