The Faculty of Environmental Engineering and Energy Technology in the Cracow University of Technology at the commission of VGT Polska Spółka z o.o. with the financial support of EU as part of Regional Operational Programme for Małopolskie Voivodeship 2014-2020 (project number: RPMP.01.02.03-12-0185/19-00) completed studies in the project entitled „The innovative VGT system for non-chemical treatment of process water” in Bauer WT Systems technology. The aim of the study was to carry out the analysis of a technique and an effect of non-chemical treatment of process water.

The diagnosis of existing issues related to water and techniques of water treatment

The stabilization of process temperatures and cooling of machines are required in the plastic processing industry. For this reason, heating and cooling devices are applied. Water is most frequently used in these processes as a transfer medium. Unfortunately, water as a medium introduces many unwanted phenomena into cooling and heating systems (e.g. limescale, corrosion, microbiological growth). They lead to the decrease in the effectiveness of heat exchange. The most frequently applied method of preventing these unwanted phenomena is the introduction of chemicals into water. However, it is not a fully effective solution as water changes its parameters, requires constant analysis of its composition, and this results in the need for adjusting the quantity and quality of chemicals. Chemicals must frequently be added to water (e.g. every two weeks or once a month – depending on water issues). High saturation of water with chemicals necessitates its replacement, i.e. draining water from the entire circulatory system into the sewage system at least twice a year. This leads to the stoppage of the production process, harms the environment, and generates additional costs. Currently, in the plastic processing industry in Poland, there are no complex solutions to issues related to process water without the need of using chemicals. Therefore, there is an urgent need for solving them by applying the method of non-chemical water treatment, all the more so because the conversations between VGT Polska employees and Customers lead to the conclusion that there are more and more issues with water „quality” and the process will continue to grow. Because of that, a decision was made to conduct industrial studies aiming at carrying out the analysis of the effect of non-chemical treatment of process water with the use of Bauer WT Systems technology.

The description of the study

The study was conducted from August 1, 2020, to December 31, 2020, at the Faculty of Environmental Engineering and Energy Technology at the Cracow University of Technology. A test stand was prepared, consisting of three test systems shown in Figures 1, 2, and 3. The aim of the five-month study was to compare water quality in the three test systems during different testing periods and to determine the susceptibility of the water tested in the systems to the growth of microorganisms and the changes occurring in pipe segments with corrosion, limescale, and biological deposits. In addition to the process tests conducted in the three technological systems shown in Figures 1, 2, and 3, an analysis of the basic quality parameters of water-pipe and process water was performed to meet the study’s objectives.

Figure 1 shows the first test system that is a circulatory system, in which no technological processes took place; its aim was to emulate the actual operating conditions of the closed circulatory system of water in industrial systems. Figure 2 shows the second test system, and the third test system is presented in Figure 3. These two systems were based on schemes reflecting tested innovative systems for non-chemical water treatment.

Presented test systems in particular consisted of the following elements:

• Test system 1, i.e., a system consisted of a tank (1) filled with 200 L of process water and a circulatory pump (2) (500 W power and 9 m3/h performance efficiency).
• Test system 2, similarly to the test system 1, it consists of a tank (1) filled with 200 L of process water, a circulatory pump (2) (500 W power and 9 m3/h performance efficiency), and is additionally equipped with an electromagnetic field generator with a Bauer Pipejet 401 HST controller (3) for water treatment, and a Bauer Mini 250 SS316 BW mechanical filter (4) with 7 candle filters (10 µm porosity).
• Test system 3 is the most developed system; similarly, as the systems 1 and 2, it consists of a process water tank (1) and a circulatory pump (500 W power and 9 m3/h performance efficiency), a Bauer Pipejet 401 HST electromagnetic field generator (6), a Bauer Mini 250 SS316 BW mechanical filter (7) with 10 µm candle filters as in the system 2, and is additionally equipped with a UV lamp.

The results of the study on the Bauer WT Systems technology for non-chemical water treatment

Picture 1. The surface of a pipe segment with a biofilm before launching the study and after three months of system 3 operating in Bauer WT Systems technology.Source: The industrial study report on the VGT Polska Spółka z. o.o. system – non-chemical water treatment, Cracow 2021, p. 31.

Picture 2. The surface of a pipe segment with limescale deposit before launching the study and after three months of system 3 operating in Bauer WT Systems technology Source: The industrial study report on the VGT Polska Spółka z. o.o. system – non-chemical water treatment, Cracow 2021, p. 31

Picture 3. The surface of a pipe segment with corrosion before launching the study and after three months of system 3 operating in Bauer WT Systems technology Source: The industrial study report on the VGT Polska Spółka z. o.o. system – non-chemical water treatment, Cracow 2021, p. 31.

Conclusions and recommendations

The scientific studies prove the effectiveness of VGT Polska Sp. z o.o. system for non-chemical treatment of process water in Bauer WT Systems technology, consisting in the impact of
electromagnetic field with variable pulsation and frequency, that removes previously formed deposits from the installation: limescale, corrosion, microbiological organisms, and prevents the formation of new deposits and pollutants. This solution does not require any service works and overhauls as the entire process of water treatment is automated.

The application of VGT Polska system allows for the reduction in activity costs by i.a.

• the reduction in energy consumption,
• the acceleration of the production process due to the recovery of 100% cooling effectiveness,
• the reduction in stoppages caused by cooling system failures,
• no need for the replacement of water due to the elimination of chemicals,
• no need for using chemicals
• lower expenditures for environmental protection
• In particular, the following conclusions may be drawn from the conducted study:
• The formation of limescale in industrial installations constitutes a serious technical problem.
• Presented pictures clearly show the positive impact of the magnetic field generator that is likely to improve physical properties in terms of the solid-liquid separation, mainly through the aggregation of colloidal particles and affecting biological properties.
• It also contributes to the removal of existing microbiological deposits (biofilm), limescale and corrosion products. The Bauer Pipejet 40 magnetic field generator prevents the growth of bacteria.
• In the system 2, the formation of harmful deposits and biofilm was not confirmed.

Recommendations

It is recommended to apply VGT Polska Sp. z o.o. system for non-chemical water treatment (operating based on the Bauer WT Systems Pipejet magnetic field generator) in order to secure water installations against the formation of limescale, corrosion and biofilm, and to remove the abovementioned previously formed deposits from water installations