Protection against rust and sludge

Electrochemical heating water treatment

Heating rust protection
elector S10 for protection against corrosion and silting in a non-diffusion-proof underfloor heating system with additional radiators, buffer tank and heat pump. elector provides the highest energy efficiency due to ideal heating water and eliminates the need for an additional heat exchanger.

The elector reaction tanks are applied for chemical-free heating water conditioning and serve to stabilize pH value, the consumption of oxygen and carbonic acid as well as the separation of circulating particles and air bubbles.

These effects are achieved by means of the design of the elector tanks and an electric field between the anode and cathode. The electric current, generated by a galvanic element, provides sufficient intensity to produce a series of chemical reactions that can continuously treat the heating water and improve its quality.

With the aid of electrochemical water treatment, which we have been using successfully since our company was founded in 1991, problematic heating systems in particular, such as underfloor heating systems with non-diffusion-proof plastic pipes, can be durably protected against corrosion and silting.

Modern heating systems can also benefit from the use of an elector reaction tank as the process enables chemical-free corrosion protection of the heating system in combination with low-salt heating water.

  • elector stabilizes the pH value of the heating water within an optimum range.
  • elector consumes dissolved oxygen and de-aerates the heating system.
  • elector separates circulating impurities and thus cleans the heating water.
  • elector provides for clear and low-salt alkaline heating water.
  • elector supports the formation of natural surface layers (corrosion protection through passivation) on the metals in the system.

Corrosion protection in heating systems – The core function of electrochemical heating water purification

Voltaic pile
A galvanic element - the voltaic pile, the precursor to our present-day batteries, consists of several galvanic elements made of copper and zinc. elector's electrochemical heating water treatment also makes use of a galvanic element.

An elector corrosion protection device is used for electrochemical heating water treatment and for corrosion protection in heating systems without the need for additional chemicals.

The process is based on the natural reaction of the metals when in contact with water, which has the optimum properties for the natural formation of a surface layer (passivation) of the metals.

Heating water quality can be brought to a level where, even in problematic heating systems with continuous oxygen input, reliable corrosion protection and the avoidance of continuous sludge formation can be ensured.

The heating water contained in the elector corrosion protection device flows through an electric current which triggers a series of chemical and physical reactions.

The process of electrochemical water treatment with an elector does not require any external energy because a galvanic element in the elector reaction tank ensures the required flow in a self-regulating manner.

Without external energy with galvanic elements

Galvanic elements, also called galvanic cells, make use of the electrochemical potential of metals. If metals of different materials are electrically connected and immersed in an electrolyte (e.g. water), this results in a natural electrical voltage.

Around the year 1800, the researcher Alessandro Volta made use of this knowledge with the invention of the voltaic pile, the precursor to today's batteries.

In the elector reaction tank, we use a high-purity alloyed magnesium anode and stainless steel surfaces as the cathode to form the galvanic element.

From the properties of the metals, the surface conditions, the water quality and the presence of dissolved gases, the electrical field is thus created in a completely self-regulating manner, which we utilise in the elector for electrochemical heating water treatment.

Electrochemistry for the improvement of heating water quality

Functional diagram elector
Primary and secondary reactions in the electric field of the electrochemical cell result in improved heating water quality.

Electrochemical water treatment with elector is based on a galvanic element that is formed in the water between an anode and the cathode surfaces.

Due to the spontaneous formation of the galvanic element, an electrochemical reaction takes place in which the magnesium, which serves as an anode, releases electrons to the stainless-steel surfaces, which serve as the cathode, and in the process itself dissolves as a metal ion.

 

Oxygen reduction and elevation of the pH value

In water with dissolved oxygen, this is reduced at the cathode, resulting in the formation of hydroxyl ions. This is called electrolytically induced oxygen reduction. The formation of the hydroxyl ions (OH-) produces alkaline water and the water constantly recirculating through the tank can rise to a pH value of >8.3.

Due to the low current density, there is no water decomposition, as would be the case with electrolysis. There is no reason to worry about the development of hydrogen gas in the elector reaction tanks.

 

Buffering the water and binding acids

Due to the non-separated anode and cathode chamber, the magnesium oxide formed at the anode combines with the hydroxide up to its low solubility limit and serves as a buffer for the pH value. Free acids can be neutralized with the excess magnesium ion.

Metal deposition

If heating water contains dissolved metal ions, under certain conditions a metal deposition can take place in the galvanic element, whereby the concentration of the dissolved metals in the heating water decreases. This effect is known as galvanic metal deposition in the electroplating industry. Due to the presence of undissolved magnesium hydroxide, it can form complexes as a flocculant with the deposited metal ions, which can be collected and flushed out by sedimentation in the elector reaction tank.

 

Limescale separation

In water where dissolved lime is present, the alkaline environment on the cathode surfaces can precipitate the lime as calcium carbonate, resulting in a reduction of the overall hardness and an accumulation of lime residues in the elector reaction tank.

 

Chemical-free heating protection

By using an elector corrosion protection device, a water quality can be achieved with which the use of corrosion protection agents can be dispensed with. In combination with fully deionized or partially salinized heating filling water, an elector makes it possible to dispense with oxygen binders, pH stabiliers or corrosion inhibitors by constantly consuming oxygen and elevating the pH value. With the use of an elector, the corrosion protection of metals in the heating system can be achieved by passivation through the formation of natural stable surface layers.

Heating venting – A positive effect of the elector reaction tanks

elector microair bubble separator
Air bubbles accumulate in the elector reaction tank and can be aerated. Depending on where the elector is installed, we always recommend the installation of a micro-bubble separator in the main flow.

The solubility of gases in water is related to water temperature. Solubility in cold water is higher than in warm water. The solubility of gases in water and their temperature dependence is defined in Henry's law.

When heating water is heated in the boiler, the solubility of the gases decreases and small gas bubbles form, just as if water is heated in a cooking pot. These small gas bubbles are carried along by the circulating water and can cause a number of problems in the heating system.

Micro gas bubbles can contribute to erosion corrosion, cause flow noises, cavitation effects in pumps or cause reduced heat transfer and local element formation (corrosion) through accumulation of larger air cushions.

Proven components for removing circulating gas bubbles are so-called micro bubble separators, which are best installed at the hottest point of the heating system. But an elector also vents gas bubbles from the heating system.

Due to the design of the elector, gas bubbles can accumulate in the tank and escape via the automatic air vent. In conjunction with electrochemical water treatment, the reduction of the oxygen content in the heating system is therefore affected in two ways.

If an elector reaction tank is installed in a bypass or in the return, we always recommend the installation of a micro bubble separator in the flow of the system, so that you can continue to benefit from the separation of micro bubbles.

Sludge and magnetite filter – elector corrosion protection ensures clean heating water

Sludge separator elector
Depending on the type of elector, different techniques are used to separate circulating particles.

Just like circulating air bubbles, particles circulating with the heating water can also cause erosion corrosion, impair the function of moving parts and lead to sludge accumulation and thus to a deterioration in heat transfer.

Particle entry into the heating water is generally caused by corrosion or loss of limestone. Especially in heating systems with corrosion processes or when systems are filled with calcareous water, a large number of particles are present in the heating water.

Sludge separators or fine filters are used to remove these particles. The use of an elector also has a significant influence on the separation of circulating particles.

Depending on the elector type, particles are separated according to the gravity principle, targeted flow control with turbulence, separation plates and strong filter rod magnets. In addition, separation is facilitated by the electrochemical formation of magnesium hydroxide.

The use of the elector effectively prevents the formation of new corrosion particles by means of ideal water quality. Old particles are collected and flushed out in the elector. The rinsing water continuously produces clean and clear heating water according to the dilution principle.

Butler water treatment device and elector
Electrochemical water treatment has been used successfully for decades. Beside the elector, a device can be seen with a galvanic element from 1950 by the American engineer Butler for corrosion protection in cooling circuits of large combustion engines.

Electrochemical corrosion protection for heating systems – proven for decades

  • There is no need to use chemical additives for corrosion protection, heating water purification becomes more cost-effective, user-friendly and uncomplicated.
  • Low-salt, alkaline water with continuous oxygen consumption dispenses with the need for additional heat exchangers, which makes the operation of heat pumps in particular much more efficient.
  • Easily controllable water quality provides proven and reliable corrosion protection for heat generators, heat exchangers and the entire heat-transferring part of the system.
  • This effectively prevents the formation of new sludge, and the heat transfer remains ideal or is even improved.
  • elector is simple and cost-effective to operate and maintain.