FAQ – Frequently asked questions


Our FAQ focuses on questions which are typically asked by our customers. If the answer to your question is not included, you can of course contact us at any time.

What is the INWATROL adplus and what is it used for?

Our INWATROL adplus is an innovative system for generating monochloramine. Monochloramine is produced by combining two components and acts as a disinfectant that is used, among other things, for the treatment of cooling water. The components are combined fully automatically via our INWATROL adplus. Since the biocide effectively disperses biofilms in the cooling system, you can be assured of hygienic operation of your cooling system thanks to its mild and targeted mode of action. Monochloramine ensures low corrosion rates by targeting microorganisms (slime-forming bacteria, sulfate-reducing bacteria, legionella, pseudomonas, algae, filamentous bacteria, yeasts and fungi).

The system can treat a system volume of 500 to 100,000 m³ and is therefore particularly suitable for large cooling systems. Dosage is based on demand and can be individually adjusted. With the help of our data management system you have the possibility to monitor your cooling system online at any time and to react directly to automated alarm notifications.

We would be pleased to present you more about our new system. Just contact us at any time.

Which water treatment program is right for my steam boiler system?

To protect your boiler system from deposits and corrosion in the long term, chemical water treatment is essential.

Deposits inhibit heat transfer and lead to increased energy consumption. A circumstance that must be avoided especially with the ever-increasing fuel prices. Corrosion can cause considerable damage to your plant. Long-term production losses are the result.

But which treatment chemicals can I use to protect my system?

First of all, it is necessary to check the extent to which steam-volatile conditioning agents can be used in your process. For example, should the steam come into contact with food, non – steam volatile products should be used. In addition, the choice of treatment chemicals depends on the type of water treatment and the quality of their additional water.

Your friendly INWATEC representative will be happy to advise you on which oxygen binders, residual hardness stabilizers and alkalizing agents can be used in your steam boiler system.

Is there a possibility to clean plant components such as heat exchangers on site?

In the best case, deposits are already avoided during operation of the plant.

Depending on which water constituents are critical, various active substances can help (for potential gypsum or lime deposits, e.g. phosphonates or polycarboxylates). In case of biofilm formation, disinfectants and/or surfactants are usually the right choice. We will be happy to provide you with technical advice to optimally match the water quality to your process.

If the heat exchanger is occupied, but still continuous, cleaning can be carried out on site in any case. This involves flowing through the heat exchanger in the bypass with the aid of a cleaning station. A cleaning solution specifically adapted to your needs is prepared in the cleaning station. Which cleaning solution is used depends on the type of contamination. Chemical analyses are carried out in advance. The system material is protected by special inhibitors during cleaning.

The cleaning and an efficient design of the cooling water treatment, to avoid deposits for the most part in the future, is carried out by experienced INWATEC employees.

How do I avoid deposits in the heat exchanger?

In the operation of heat exchangers, many different parameters play a decisive role in addition to the water quality. In particular, the flow velocity is an important aspect in the mode of operation.

We recommend a flow velocity of at least 1 m/s. However, the flow velocity must not be too high either. Too high a flow velocity can lead to corrosion, e.g. erosion corrosion. Please be sure to observe the manufacturer’s specifications in this regard.

The maximum wall temperature plays an important role. If possible, we place the water treatment on your most critical heat exchanger. In addition, to the lime-carbonic acid equilibrium for estimating the tendency for lime deposits, we also calculate the indices for e.g. phosphate, zinc or silicate solubility to ensure trouble-free operation. Finally, it is of course important to effectively limit microbiological growth to avoid the formation of biofilm.

Have we aroused your interest? Then contact us by e-mail at info@inwatec.com.

Should I turn off my ventilators on the cooling system if the legionella concentration is too high?

In the past, the recommendation was often made to switch off the fan on the cooler in the event of an increased legionella concentration. But does this measure really make sense?

The answer is: No!

If the fan in the cooler is switched off, the temperature of the cooling water increases. As a result, microbiological growth is favored. The legionella concentration can then increase even further.
In addition, the droplet separator (which prevents aerosols from escaping from the evaporative cooling system) no longer receives an optimal flow, so that aerosols can be discharged.

It would be better, in the case of an increased legionella concentration, to lower the blowdown limit. In this way, more water is discharged from the cooling system, which favors the dilution effect. In addition, the biocide dosage should be increased.
A subsequent root cause investigation should then elucidate how the increase in Legionella concentration occurred.

You are welcome to contact us if you need help with this. We will be happy to assist you.

How does corrosion occur and how can I measure it?

Corrosion is a chemical-physical reaction between metals and their environment and quickly leads to high maintenance costs or even production losses in cooling circuits. There are many types of corrosion in cooling systems, such as microbiologically influenced corrosion and pitting corrosion. In microbiologically influenced corrosion, anaerobic bacteria, for example, can oxidize the steel, while “pitting” is caused by anions (e.g., sulfate or chloride) that promote corrosion, among other things.

The typical measurement of corrosion rate is made using corrosion coupons and is measured in mm/year of material loss. However, in addition to material loss, the type of corrosion is also important and can be determined by using the corrosion coupons. For this purpose, the simple installation of the coupons in a measuring fitting can provide more information. In addition, INWATEC has the possibility to monitor the corrosion coupons in our INWAview system with the help of a high-resolution HD camera. Thus, the coupon can be viewed at any time and mechanisms of corrosion can be detected at an early stage and appropriate measures can be taken.

Which biocides do I use in which application area?

In principle, biocides are divided into oxidizing and non-oxidizing biocides.

Oxidizing biocides act through a chemical reaction. While the microorganism is oxidatively damaged, the disinfectant is reduced. Often these redox reactions are pH dependent. Oxidizing biocides often react with organic water constituents.

Non-oxidizing biocides, on the other hand, have a wide variety of effects. For the success of disinfection, a sufficient concentration of active ingredients is obligatory here. The active ingredients can act both at the cell membrane and within the cell. The mechanism here defines how fast the biocide acts. Slow-acting biocides are unsuitable for dynamic systems. In terms of wastewater, this type of product affects the GL value, the COD and, in some cases, the AOX concentration.

Depending on the application, even a combination of active ingredients can be useful. Non-oxidizing biocides are less sensitive to organic cooling water constituents. The combination with oxidizing agents can have a synergistic effect in highly loaded cooling systems.

In any case, please consult a competent contact person. The use of biocides must be targeted and correct for legal and environmental reasons. According to the motto: As much as necessary, as little as possible. We will be happy to support you here.

What should you pay particular attention to when treating boiling water?

In boiler water treatment, special attention must be paid to three factors: Operational safety, occupational safety and economic efficiency.

Operational safety includes compliance with guidelines, documentation of water analyses, flawless treated feedwater, availability of all operating equipment and the maintenance schedule.

In the context of boiler water treatment, occupational safety refers to the handling of chemicals for water treatment by skilled persons. This also includes the risk assessment and the testing of safety fittings.

Economic efficiency includes, above all, a cost-benefit calculation of the amount of steam and the discharge. In addition, the number of damages and repairs must be taken into account. The current state of the technologies as well as the efficient
heat recovery should also be integrated into the water treatment.

INWATEC will of course help you to realize all three factors properly and in the best possible way. You will not have to worry about your boiler water in the future thanks to our help.