Sistemyi water preparations: physical and chemical water preparation

Existing systems of water preparation can be divided on two basic categories:

• Chemical (reagentnaya)
• Physical (bezreagentnaya)

Chemical (reagentnaya) water preparation

Means direct addition in system of chemical substances which umyagchayut water or suppress corrosion.

Fosfatirovanie. It is system, in where crystls of polyphosphates are slowly dissolved in a water stream, covering any metal parts which contact to water, by a thin film. This film effectively prevents formation of adjournment and corrosion on metal pipes. Dispensing process is automated, polyphosphates are added in water to proportionally cost of water. Water after processing cannot be used for drink and cooking.

Water softener (ionoobmennyiy the filter). This system, in where water is passed through a membrane which effectively replaces calcium from water on sodium from a membrane. In due course all ions of sodium in a membrane will be replaced. To return ability of a membrane to replacement of ions of calcium by sodium, it is necessary for recycling. A membrane place in a strong hydrochloric solution, thus sodium ions pass from a solution in a membrane, and calcium ions - in a solution. During regeneration by the system it is impossible to use.

After regeneration the fulfilled solution merge. The fulfilled solution concerns a category of aggressive liquids, its dump needs to be co-ordinated in the corresponding organisations.

At infringement of terms of regeneration service life of an expensive membrane will considerably be reduced.

Furthermore umyagchennaya water cannot dissolve karbonatnyie adjournment, they should be cleared regularly acid.

Also use umyagchennoy waters in central heating systems since umyagchennaya water korrozionno is active is not welcomed.

The control over corrosion

In the systems containing water, there are two basic ways of suppression of corrosion:

• Removal of oxygen from water, mechanical or chemical deaeratsiya;
• Addition ingibitorov corrosion.

Ingibitoryi corrosion

Ingibitor corrosion this substance which effectively reduces corrosion degree in system. Principal views ingibitorov corrosion:

• passiviruyuschie (anode) ingibitoryi - form a film oksidov on a metal surface. These are the best ingibitoryi because are spent in small amounts, their protective films strong and are fast restored at damage.
• osaditelnyie (cathodic) ingibitoryi - reagents which form insoluble substances which can cover and protect a surface.
• Adsorbing ingibitoryi - the polarised substances, their charges draw them to a metal surface. Usually it is organic substances.

Passiviruyuschie ingibitoryi

The substances containing hromatyi, nitrites, molibdatyi (salts molibdenovoy acids) and ortofosfatyi can be examples passiviruyuschih (anode) ingibitorov. All of them are oxidizers and promote passivirovaniyu increasing electric potential of iron. Hromatyi and nitrites do not require oxygen and it does their most effective. However from reasons of safety of health and environment, use hromatov and nitrites is essentially reduced.

Molibdatyi and ortofosfatyi too are excellent passivators. Though molibdatyi it is expensive material, they can be very effective ingibitorom, especially in a combination to other chemicals.

Osaditelnyie ingibitoryi

Ortofosfatyi is a good example osaditelnogo ingibitora which shows double action, acting as an anode passivator and cathodic osaditel.

Adsorbing ingibitoryi

Adsorbing ingibitoryi should be polar to be adsorbed, for example as aminyi. Often these molecules have double functionality. In them the group which is adsorbed in a metal surface contains gidrofilnaya, and the opposite waterproof group prevents the subsequent contact of metal to water.

Silicates

Many years silicates were used for corrosion suppression in water solutions, especially in systems with potable water. Their mechanism of inhibition is not completely studied yet. Most likely they suppress corrosion by means of the adsorption mechanism. Silicates are slow-acting ingibitorami, in some cases it can be required 2 - 3 weeks for complete protection of system.

Ingibitoryi copper corrosion

The most effective ingibitorami corrosion for copper and its alloys are aromatic tria-zoles, such as benzotriazole (BZT) and tolyltriazole (TTA). These kompaundyi (difficult structures) form communications directly with oksidom copper on a metal surface, forming hemsorbtsionnuyu a film.

Factors about which it is not necessary to forget

That action ingibitorov corrosion was effective, contact to a metal surface is necessary for them. Then the protective film on its surface will be stable. Therefore before system processing it is necessary to clear it of adjournment previously.

Efficiency of suppression of corrosion also depends on concentration ingibitora in water.

If at system there are pipes, the equipment from different metals, it is necessary to use the products containing a complex ingibitorov enough to protect each metal of system. In addition to such often used metals and alloys as iron, copper, a steel and a brass, it is necessary to think and of aluminium.

Usually this threw is protected by a film oksida aluminium which prevents corrosion occurrence in water (or on air), but under the influence of acid or strong alkalis the film oksida aluminium decays, baring metal. Some kinds of water create the alkaline environment in central heating system that leads to corrosion of aluminium and formation of accompanying gases. With growth of number of systems of the central heating containing aluminium, all becomes more reasonable application neutral (not sour and not alkaline) ingibitorov than corrosion.

Physical (bezreagentnaya) water preparation

Apparently from the name, this group of systems functions without consumables. The part from them uses the power supply for work, others manage and without it. Many systems which can be divided into groups enter Into this category:

• Constant magnets;
• Electromagnets;
• The electronic;
• elektroliticheskie;
• The electrostatic.

All these systems effectively change behaviour of water. At use of these systems level of adjournment decreases or the interval between system clearings increases. Some of systems are capable even to delete existing adjournment from system.

In essence, physical ingibitoryi adjournment, magnetic, elektroliticheskie or electronic, work similarly, changing behaviour of natural salts in water so, that they remain in a solution, instead of on walls of pipes.

Constant magnets

This most simple of systems of this class. Is group of the constant magnets connected among themselves. Water passing through the system is processed by a magnetic field. The magnetic field forces water to accumulate electrostatic charges that leads to time changes in the form of crystals of salts. It changes their form from a usual rectangular parallelepiped on iglopodobnuyu structure which is more subject to washing away from system, than to sticking to surfaces.

For work it is not required a food and consumables. The system runs into system. There are the workings out established on a pipe without vrezok in system.

Models steal up on diameter and a water stream. There are restrictions on water temperature.

The electromagnetic

Are similar to systems with constant magnets, but have more powerful magnetic field and serve longer. Should be usually established very close to a copper since they process only the water proceeding through them. If the stream stays, accumulation of water by charges will cease until water movement will not be started over again.

Unlike the magnetic can work on the big streams of water and at more heats, but is more expensive magnetic and require careful clearing of an external surface of a pipe in an installation site.

The electronic

Electronic systems of water preparation differ that their work does not depend on speed of a stream of water. The high-frequency signal affects water at molecular level by means of the system established over a pipe. Effect on water appears 24 hours a day in both directions, on and against a water stream, processing simultaneously all water in system.

The high-frequency radio signal changes characteristics of crystallisation of salts in water, preventing formation of new adjournment.

Some systems of this group are capable to delete old adjournment and to cause effect passivirovaniya in metals of pipes, preventing corrosion.

The Electrolitichesky

The small electric current, passing through water, effectively changes molecular structure of formed crystals of adjournment, preventing formations of rigid adjournment on coppers, pipes. This system modifies physical properties of ions, but chemical reaction does not occur. In a water solution of salt of calcium, magnesium and some other salts are partially ionised and consequently they are influenced by an electromagnetic or electrostatic field. The increase in degree of ionisation of ions in a solution reduces formation of adjournment.

The electrostatic

Kinetic energy of a moving stream of water creates a charge which is transmitted to water. It infringes stability of particles in water which are in a balance condition, having equal charges. Neytralizuya charges and infringing an equilibrium condition of a mix the system forces particles to drop out in a deposit, carrying away for itself of substance which can form a scum. The system causes early, uncontrollable sedimentation small, not completely generated crystals. Thus formation of rigid adjournment is prevented, and soft shlam is washed away from system.

It is granted by company Gidroflou

Date of the publication 18.12.05