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Ultrasonic vortex generators AVS-100. Unit application

 Cavitation technology application

 Cavitational effect is accompanied by microexplosions, ultrasound and also by mechanical cuts and encounters from exposure of the hundred of cuts pairs which are moved towards each other with the high linear speed. The value of that speed is reach to a few dozen of meters per seconds which gives a possibility to cut dispersed matters to the smallest microparticles. In fact it is a micropulse. Per one minute occur hundreds of thousands of micropulses.

 The methods of petroleum and petroleum residues processing are based on phase transition which is typical for dispersed system. An effect on phase transitions kinetics can be achieved by chemical agents and physical fields. As a result the nuclear radius is changed, changed also the thickness of adsorptive solvation sphere of compound recurring unit. This unit is an element of petroleum dispersed system. These processes allow increasing the desired petrochemical products yield, improve their quality and reduce energy consumption.

Light fuel product yield increasing

 The idea of long-chain organic compounds crushing into short-chain which create a new compounds leads to creation of light fuel products is not new. Those researches were started in the 1960s by soviet scientists. But today, at the time of high prices on the petroleum and its processing cost increase, cavitational technologies are particularly topical.

 For today the method of cavitational oil processing is most qualitative. Specific density of light fuel products is increased after cavitational treatment of petroleum.

Vortex Cavitational Hardware

 The main direction of an ultrasonic vortex cavitational generator application (or AVS unit by PC GlobeCore) is petroleum industry.

Structure of AVS unit

 Cavitational hardwares are used for creation of oil-fuel, oil-mazut mixtures and emulsions. These emulsions are often used to increase the combustion efficiency or utilization of watered fuels.

 Cavitational process has a great destruction power which can be used for desintegration of solid substances contained in liquids.

 A hard spot crushing is one of the applications of this process which is included to heavy fuels.

 This process is also used in order to increase the caloric content of the heavy fuel oil.

 Cavitation can be used in fuel treatment process. During this treatment fuel obtains additional purification and at the same time fraction ratio is redistributing to the light fraction. The tests of such fuel are demonstrated decreasing of soluble gum amount.

 After treatment by AVS is increasing the quality and caloric content of fuel. As a result we can reach complete fuel burning and decreasing the mass of contaminants. Investigation of cavitation influence on quality of fuel is still urgent and that research is conducted by different private companies and research institutes.

 Cavitational devices can increase hydrocarbon fuel viscosity. As a result necessary heating value is decreasing and at the same time is increased fuel spraying dispersion.

 AVS unit was created as a reactor for large industrial productivity. This ultrasonic generator can be successfully used for:

• petroleum treatment for pipeline transportation which leads to petroleum viscosity decreasing, destruction of paraffin leads to reduction of the sedimentation on pipe walls;
• pre-cracking petroleum treatment for the purpose of light fraction yield increase.

Experimental Results: Light fuel product yield increasing

 Experimental researches show the following results:

– cavitational treatment allows increasing the fraction yield at the same volatilization temperature.

 It follows that ultrasonic vibrations accelerate petroleum diffusion in paraffin, intensify the process of paraffin destruction. Acceleration of paraffin dissolution is caused by intensification of oil blending process (on the line oil-paraffin) and influence of pressure surge.

Ultrasonic vortex generators AVS-100. Unit application

 Cavitation technology application

 Cavitational effect is accompanied by microexplosions, ultrasound and also by mechanical cuts and encounters from exposure of the hundred of cuts pairs which are moved towards each other with the high linear speed. The value of that speed is reach to a few dozen of meters per seconds which gives a possibility to cut dispersed matters to the smallest microparticles. In fact it is a micropulse. Per one minute occur hundreds of thousands of micropulses.

 The methods of petroleum and petroleum residues processing are based on phase transition which is typical for dispersed system. An effect on phase transitions kinetics can be achieved by chemical agents and physical fields. As a result the nuclear radius is changed, changed also the thickness of adsorptive solvation sphere of compound recurring unit. This unit is an element of petroleum dispersed system. These processes allow increasing the desired petrochemical products yield, improve their quality and reduce energy consumption.

Light fuel product yield increasing

 The idea of long-chain organic compounds crushing into short-chain which create a new compounds leads to creation of light fuel products is not new. Those researches were started in the 1960s by soviet scientists. But today, at the time of high prices on the petroleum and its processing cost increase, cavitational technologies are particularly topical.

 For today the method of cavitational oil processing is most qualitative. Specific density of light fuel products is increased after cavitational treatment of petroleum.

Vortex Cavitational Hardware

 The main direction of an ultrasonic vortex cavitational generator application (or AVS unit by PC GlobeCore) is petroleum industry.

 Cavitational hardwares are used for creation of oil-fuel, oil-mazut mixtures and emulsions. These emulsions are often used to increase the combustion efficiency or utilization of watered fuels.

 Cavitational process has a great destruction power which can be used for desintegration of solid substances contained in liquids.

 A hard spot crushing is one of the applications of this process which is included to heavy fuels.

 This process is also used in order to increase the caloric content of the heavy fuel oil.

 Cavitation can be used in fuel treatment process. During this treatment fuel obtains additional purification and at the same time fraction ratio is redistributing to the light fraction. The tests of such fuel are demonstrated decreasing of soluble gum amount.

 After treatment by AVS is increasing the quality and caloric content of fuel. As a result we can reach complete fuel burning and decreasing the mass of contaminants. Investigation of cavitation influence on quality of fuel is still urgent and that research is conducted by different private companies and research institutes.

 Cavitational devices can increase hydrocarbon fuel viscosity. As a result necessary heating value is decreasing and at the same time is increased fuel spraying dispersion.

 AVS unit was created as a reactor for large industrial productivity. This ultrasonic generator can be successfully used for:

• petroleum treatment for pipeline transportation which leads to petroleum viscosity decreasing, destruction of paraffin leads to reduction of the sedimentation on pipe walls;
• pre-cracking petroleum treatment for the purpose of light fraction yield increase.

Experimental Results: Light fuel product yield increasing

 Experimental researches show the following results:

– cavitational treatment allows increasing the fraction yield at the same volatilization temperature.

 It follows that ultrasonic vibrations accelerate petroleum diffusion in paraffin, intensify the process of paraffin destruction. Acceleration of paraffin dissolution is caused by intensification of oil blending process (on the line oil-paraffin) and influence of pressure surge.

Cavitation is one such recent technique which has been found to be substantially beneficial in wastewater treatment.

Cavitation can be described as formation, growth and sub-sequent collapse of cavities releasing large magnitudes of energy locally, creating conditions similar to hot spots, and also generating strong oxidizing conditions by way of production of hydroxyl radicals and also hydrogen peroxide.

The efficacy of cavitational reactors can be significantly enhanced by combining cavitation with other oxidation processes or by using catalysts and/or additives.

Cavitational reactors can be recommended as pre-treatment methods of waste purification.

By combining conventional and cavitational technologies we can achieve complete purification of industrial wastewaters which contain heavy metal ions, chromium compounds, phenol and also organic and inorganic substances.

Engineers from PC GlobeCore have used the cavitational principle to design AVS unit or Magnetic Vortex Activator. In cavitating water purification devices the extreme conditions of cavitation can break down pollutants and organic molecules.

The main way of AVS unit application is wastewater treatment. Usage of this unit leads to acceleration of industrial wastewater neutralization, reducing energy and reagents consumption.

Consider the following example “wastewater treatment from phenol and other organic contaminants”.

“Cavitation can be described as formation, growth and sub-sequent collapse of cavities releasing large magnitudes of energy locally, creating conditions similar to hot spots, and also generating strong oxidizing conditions by way of production of hydroxyl radicals and also hydrogen peroxide”.

We have designed new uninterrupted way of wastewater treatment  from phenol and other organic contaminants by means of vortex layer (cavitational process). We tested artificial wastewater by Intensifier of Technological Process AVS. These wastewaters contain similar concentration of phenol, acid and contaminants as real manufacturer’s wastewaters.

Research suggests that Intensifier of Technological Process provides qualitative treatment of wastewater from phenol at lower costs to compare with other known methods.

Conditions of the wastewater treatment by AVS unit from phenol concentration 0.5-10 g/dm³ and acidity of the medium 5 g/dm³ are as follows:

• oxidizing agents: potassium bichromate (concentration 0.2-5 g/dm³); manganese dioxide (concentration 1.2-10 g/dm³); potassium permanganate (concentration 0.1-1.0 g/dm³);
• wastewater’s temperature – 20–45 °С;
• oxidization time – 0.1-2 seconds.

AVS unit industrial process flowsheet is much simpler in technological execution than contemporary industrial process flowsheets.

According to this process flowsheet phenol wastewater enters to equalizing reservoir which is made to blending and equalization of phenol concentration. Wastewater and potassium bichromate (oxidizing agent with concentration 150–300 g/dm³) inject to the unit working chamber by means of pump.

Phenol oxidizes in apparatus from where wastewater injects to another vortex layer machine. In the second stage hexavalent chromium regenerates by ferrous sulfate in alkaline medium and at the same time neutralizes and settle Cr³⁺. As alkaline agent can be used lime, soda or other reagents.

While wastewater treating from phenol, oxidized another organic impurities. Level of formaldehyde content decreases from 10 g/dm³ to 50-100 mg/dm³, methanol – from 6.4 g/dm³ to 2.3 mg/dm³, diphenylol propane – from 4.6 g/dm³ to 150 mg/dm³.

Following conditions are recommended to decline the wastewater phenol level:

• Incoming water acidity level – at least equal to 3-5 g/dm³;
• Wastewater temperature during oxidization  – 45 °С (if the wastewater contains gums, temperature should be increased to 45–60 °С);
• Oxidizing agent consumption – 2.5-3.0 weight parts for 1 gram of phenol;

AVS unit productivity: for AVS-100 – to 10 m³/h, AVS-150 – to 25 m³/h.

Application of AVS unit permits to:

• reduce energy consumption in 10-15 times;
• reduce oxidizing agent consumption in 1.5-2 times
• reduce the working area of waste treatment facilities in 1.5-2 times

Qualitative treatment of wastewater from phenol and other organic contaminants has a great practical importance within different branches of industry.

In many cases, contemporary ways of usage by enterprises do not provide high qualitative treatment (degree of phenol decline is 75-90%). These ways have defects such as long process duration from 3 to 5 hours, long processing time, high reagent consumption (pyrolusite, kali bichromate or sodium bichromate), and process temperature is 95–100 °С, bulk equipment, necessity of large working area.

We have designed new uninterrupted way of wastewater treatment from phenol and other organic contaminants by means of vortex layer. We tested artificial wastewater by Intensifier of Technological Process. These wastewaters contain similar concentration of phenol, acid and contaminants as real manufacturer’s wastewaters. Content of wastewater is indicated in the table 1.

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The Intensifier of Technological Process (or AVS-100) can be successfully applied at the fuel industry for liquid hydrocarbon fuels modification by means of water. This unit can be used for production of motor and heating fuels which have improved operational and ecological characteristics.

The mode of obtaining of modified liquid hydrocarbon fuel includes mixing of hydrocarbon components and the water by means of rotate electromagnetic field. Ratio of the hydrocarbon component and water is 60 to 40 and 98 to 2.

 To increase the octane number of blending components we injected oxygenates which was equal to 5-10% of all mass of the hydrocarbon component.

 During less than 10 seconds the mixing components rotate in the electromagnetic field. Fuels obtained by this method allow reaching their complete burning and increase technical and economic parameters.

 A method of obtaining an emulsion fuel, comprising the simultaneous mixing of fuel, water and the stabilizer (surfactant) to maintain the stability of fuel-water emulsions.

 According to this method we mix water and SAA and after that we add to this solution the fuel or we mix fuel, water and stabilizer simultaneously. Injection of the fuel into emulsion proceeds with the ratio of speed and flow equal to the value 1:1:50.

 Main insufficiency of this method is usage of SAA. As a rule, utilization of this component gives negative operational and ecological effects such as carbon deposit on the rings and cylinder, high concentration of CO and CH in the propulsive gas. Besides, this technology is very difficult and insecure. Even small irregularity of proportions of the base components flow speed can destroy emulsion (emulsion become unstable).

 The technical result is increase of economic and operational characteristics of fuels.

 The method includes dispersive water fractionation in the fuel to the size 1 micron by means of fractionation like sieve, or statical, rotary and ultrasonic mixing machine. Obtained emulsified fuel contains emulsified system which includes the one of the compound sorbidol ether.

 By this method modification of the diesel fuel leads to decreasing of the cetane number, to viscosity growth and increasing of the soluble gum content. The fractionation process by means of different types of mixer machine and application of sieves is very difficult. This process performed cyclically to obtaining the droplet of water of desired size.

Intensifier of Technological Process AVS-100. General view

At room temperature the time of preserving stability of this emulsion not to exceed three months, that not enough for industrial utilization.

 Relative to above-described method utilization of Intensifier of Technological Process allows obtaining stable antifloating fuels by means of rotate electromagnetic field which is created in the working space of the AVS unit.

 How do we reach this? During 10-15 seconds we mixed the components at the room temperature into the rotate electromagnetic field created by AVS unit. Water content in the hydrocarbon component reaches the value 2-40% of the mass. Obtained by this method water-fuel emulsions are very stable; so you don’t need to use SAA.

 Invention suggests utilize oxygenates as additives which increase octane and cetane numbers. We have used water-soluble oxygenates including spirits (such as ethyl alcohol) and ethers.

 After fuel modification by means of water we have obtained fuel which is fit with all standards but has higher octane number (increased by 2-3 positions). You can see the comparison results of the exhaust gases content before and after modification in the table 1. As you can notice, CO and CH value content is reduced.

 Invention can be implemented by all producers of fuels including producers of heating oil. Application of this unit allows obtaining stable and not peeling liquid hydrocarbon compositions with the water.

 Fuel modified by means of water fits with standards and has higher value of octane number relative to the base sample. Testing of the fuel samples modified by water allows discovering their detergent effect.

 This emulsion permits to reach high total fuel and carbon sediments burning, also increases technical and economic indices of fuels.

 You can reach this result by using The Intensifier of Technological Process and application of ferromagnetic particles.

 Exemplary embodiment

Example 1.

 Reagents processing. The capsule from steel was filled by – 1750 ml of benzine (0.85-0.9 % of volume), – 500±50 g of ferromagnetic particles, – 2-40% of water and 5-20% of oxygenates. This capsule was closed hermetically and processed by Intensifier of Technological Process during 10-15 seconds. As result we obtain a stable water-fuel emulsion which is nonsegregating over a long period of time.

 Application of AVS unit permits to change molecular structure of fuel and water during the mixing process. Blending of water and fuel generates a new chemical compound which cannot be destroyed.

 Water content in the benzine depends on processing condition of hydrocarbon molecule by means of vortex layer. These molecules undergo inside structural changes, also change their physicochemical properties.

Example 2.

In the same way as in the previous example, capsule was filled by 1750 ml of diesel fuel and 3-5% of water.

As result it was obtained the water-fuel emulsion which has high ecological characteristics and high cetane number.

Example 3.

In the same way as in the first example, capsule was filled by black oil. Obtained water-fuel emulsion allows reaching high total fuel and carbon sediments burning, decrease nitric oxide emissions into the atmosphere and also permits to remove difficult and expensive devices for black oil dewatering and cleaning of precipitated water.

Industrial production of fuels by means of Intensifier of Technological Process permits to obtain considerable economical effect by using the water as a fuel and reduce emissions into the atmosphere of pollutants and other substances.

Table 1

The one of the main problems of contemporary construction material production is problem of obtaining concrete compositions of high quality. The possible way to resolving this problem is modification of a cement stone structure that allows using all durability potential of the crystalline hydrates and also increases the quality of all concrete components. We have investigated the ways of concrete quality improvement by using nanotechnologies and nanomaterials such as magnetic activation.

 Let`s consider the results of application of AVS unit (Intensifier of Technological Process by PC GlobeCore) during the production of fine-grained concrete compositions.

 We have used standard methods to research the durability characteristics and physical and mechanical properties.

 We have made the test of mixing concrete components four times. This was made in order to provide homogenization of concrete components including nanoagents.

 To intensify the process of components mixing in AVS unit we have used ferromagnetic particles covered by polymer coating. In other cases we have investigated the influence of Intensifier of Technological Process on production of magnetic mixing water.

Intensifier of Technological Process AVS-100. General view

Solutions of the one composition were made from the same fillers. Mixture ratio of components is 1 to 3. Cement-water factor ranged from 0.6 (for examples which were hydrated by the magnetic water) to 0.8 (for examples which were hydrated by the ordinary water), content of nanoagents ranged from 0.5% to 2%.

Time of water processing by the variable magnetic field is from 2 to 5 seconds.

 Results of test show that even small quantity of carbon nanoparticles and their application increase the complex of properties of concrete.

 The maximum degree of the test sample durability can be obtained by adding of additive agent whom is equal to 1% all batching mass.

 Durability peak is in the range from 0.5% to 1% of nanoagents content in concrete. Interesting that the durability of nanomodified samples exceeds the durability of control samples during compression testing in 5.8 times and during bending test in 5.1 times.

 Results of testing you can see at the below figures.

These figures show that the samples which were made only by using magnetic water have the durability less than 20-25%. So, preparing of the concrete mix by using AVS-100 unit is more qualitative.

But when we added more than 1 % of nanoagents we observed reduction of durability degree during each of compression tests and bending tests.

 As result of our investigations we were conclude that nanoagents have a great impact on the durability values of concrete mixes and processes of concrete structure formation. It is reasonable to suppose that nanomodified concrete will have the best values of durability and longevity.

 Usage of the carbon nano-particles in the concrete production has great prospective future.

Expanded clay industry

 In the process of expanded clay production the argillous raw material homogenizes and mills in the drilling mud mixers and rollers. But these equipments not ensure qualitative desintegration. As result we obtain the expanded clay of low quality.

 Insufficiently desintegration and homogenizing of raw materials lead to the result when even 3% of carbonate inclusion in the low-melt expanded clay can make it unusable. Obtained in such way expanded clay lose its durability or destroyed upon storage by the reason of CaO hydration.

 The oversanded glay with free SiO₂ content to 10-30% is also not suitable for expanded clay production. All those problems can be successfully resolved by using Vortex Layer Machine – AVS-100 PC GlobeCore production. When we are using the unit AVS-100 for desintegration and homogenizing of the burden material we obtain the expanded clay of general engineering and special designations. In this case we also reduce the volume weight and increase the durability.

 Table 1

Results of desintegration and homogenizing of the burden material for expanded glay production by using AVS-100

Slip treatment of CaS0₄ with content of free SiO₂  up to 40% leads to reducing of volume weight of the expanded glay in 2 times and increasing of its durability. The expanded glay strength-density ratio is almost in two times higher in the expanded clay, which is made from the burden material the unit AVS-100. The reason of sharp properties increase of the expanded clay is obviously activation of the high-silica sand caused by creation of active center or other words free radicals creation which are produced by the reason of the bond rupture of Si—O.

Intensifier of Technological Process AVS-100. General view

 Activation of SiO₂ leads to active participation of the expanded glay in the silication and glass formation. After the expanded glay baking in its granules are absent coarse particles of SiO₂, which are the concentrator of tension. Presence of SiO₂ in the glass content increases its durability and thermostability.

 Good results are obtained by dry treatment of the raw material by the vortex layer. For example, from the monothermite (hydromicaceous clay) we obtained the light-weight fireproof aggregate which has the volume weight in 2 times lower but the durability in 2 times higher than which we have for the control sample (experiment 3, table 1). The positive result was obtained by dry treatment of the multicomponent burden material (with 50% ashes content) by vortex layer.

 The given examples shows you that the application of AVS-100 (Intensifier of Technological Process) is very perspective for obtaining of the expanded glay of high durability and thermostability from oversanded and over-carbonized materials, burden materials which contain up to 50% of  waste product, for example, the coal ash.

 Cellular concrete production

 Cellular concrete is made in result of solidification preliminarily blown-out mixture of the cementing medium, water, silicious component using gasifier of components. Most frequently as foaming agent used aluminum powder. The aluminum powder reacts with water solution of calcium hydroxide and disengages hydrogen.

 In fact, the quality of cellular concrete is high when the size of pores decreasing and homogeneity of porosity is rising.

 In order to ensure best quality of cellular concrete is necessary to distribute aluminum powder in its weight and increase the degree of dispersion. Besides, the one of technological factors which determines the cellular concrete structure is content of active CaO in mixture.

 As usual the preparation of gasifier reduces to partial paraffin film stripping from aluminum particle surface by mixing of this film with water and surfactant species, after these action need to introduce suspension into solution.

 Because of low efficiency of mixing devices, paraffin film practically not removed.

 In addition, there is a coagulation of aluminum particles, which leads to the local concentration of gas in the products, the appearance of voids and cracks. Because of shortage of gas emission in the case of gas silicate production is necessary to introduce up to 25% of lime into the mixture.

 The necessity of additional introduction of a lime into the mixture is specified by requirement to obtain the durability of concrete which allows to keeps it in vesicular condition by the end of gas emission using the hydration cementation.

 Application of AVS-100 unit for preparation of aluminum powder suspension in production of the gas silicate allows avoiding the coagulation of aluminum particles, raises their activity, gas yield and homogeneity of the mixture. At the table 2 you can see some of the comparative data of physicochemical properties of the gas silicate which was made by using the aluminum suspension fabricated by different methods.

 Table 2

Comparative data of physicochemical properties of the gas silicate which was made by using the aluminum suspension fabricated by different methods

 The table shows that usage of treated aluminum suspension by AVS-100 allows to obtaining the gas silicate which has the durability up to 10-30% and quality index up to 20-60% higher in comparison with the control sample (table 2, experiment 1).

 Application of Intensifier of Technological Process gives a possibility to decrease by 10 % gasifier consumption and by 2% lime consumption. At the same time there is no weighting of gasifier. On the contrary, the volume weight of the gas silicate is reduced but its durability is increased. Obviously, the quality of the blown-out concrete can be increased by the treating process by AVS-100 unit in the vortex field of sand-lime mixture or in the sand-cement mixture on purpose of activation of SiO₂ like we do the same in expanded-clay aggregate production.

The silica brick production

 The raw material for the silica brick production is the high-silica sand (92-95% of dry mixture) and the lime (5-8%). Structural capabilities of the brick directly depend from the degree of activation of SiO₂ andmixing uniformity of components.

 According to this fact, application of AVS for the treatment of dry mixture by the reason of mixing and activation of components is of the utmost interest. We have investigated the ways of sand-lime mixture activation by spillage of material through the vortex layer of the unit AVS-100.

 It is interesting to note that, in this short-duration treatment of the mixture (mixture particles locate into the vortex field for a fraction of a second) the grinding of the sand and the lime is not observed. The degree of activation can be determined by the changing of mechanical properties of obtained silica brick.

 Table 3

 As you can see from the table by the short-duration treatment of the mixture you can increase the durability of the silica brick in 3,5 times.

Obviously, similar processing sand-lime, lime-ash and lime-silica mixtures leads to an marked increase of the mechanical properties of silicate concrete, which are widely used in prefabrication.

Wastewater treatment from hexavalent chromium and other heavy metals

The purification and safe disposal (neutralization) of industrial waste water effluents represent a very important ecological problem. The principal problem or requirement involves reducing the concentration of harmful impurities to concentration levels below their maximum allowable concentration limits. In fulfilling this requirement the amount of fresh water consumption needed to maintain the water level in the circulating or recycled water supply system is also reduced, and the operating life of production equipment or lines is concomitantly prolonged as a consequence of decreased corrosion and sediment formation or precipitation (scaling).

In many cases the use of traditional methods, such as settling or sedimentation tanks and ponds, or flotation devices, are not effective or efficient enough for operation, and so more advanced, progressive, and forced methods must be employed, such as treatment by Magnetic Vortex Activator AVS-100 (electromagnetic unit with velocity layer), for instance. The effect of electrophysical factors (electron acceleration, etc.) on contaminated water leads to rapid decomposition of many chemical impurities or contaminants to give inactive (non-harmful) substances.

Designed for last few years electromagnetic units with velocity layer have a wide usage today. These machines can be use by the different branches of industry for intensification of technological (chemical and physical) processes and even for treatment (sterilization, neutralization) of waste water.

From the large quantity of waste water types usually occurs waste water contaminated by chromic compound, fluorine, arsenic, phenol and other harmful and organic impurities. Such waste waters are characterized for the many of machine-building plants.

We have investigated the characteristics of waste water samples before (table 1) and after (table 2) treatment by AVS-100.

Table 1

Characteristics and content of industrial waste water

We have investigated the treatment effectiveness by using Magnetic Vortex Activator AVS-100 from two methods: I^th method – sterilization of chromium-containing wastewater by Cr⁶⁺ up to Cr³⁺ and using the reagent (sulfuric acid iron); II^th – combined neutralization and treatment from the heavy metals ions of chromium-containing wastewater and acid-base wastewater.

Intensifier of Technological Process AVS-100. General view

The process of chromium-containing waste water purification is as follows. The waste waters which contain the specific hexavalent chromium concentration at the rate of 10-15 m³/h from the flow-equalization basin enter the AVS-100. At the same time from the consumption tank by dosing pump to the AVS-100 deliver project quantity of ferrous [iron] sulfate solution (concentration 30-60 g/dm³). At the AVS-100 carry out the waste water treatment by FeSO₄ solution, as result occurred regeneration of Cr⁶⁺ to the value Cr³⁺. Completeness of chromium regeneration was verified by the proximate analysis using the diphenilcarbazide and also by the colorimetric method. Sterilized waste waters entered to the neutralization and purification from trivalent chromium. During the research we was changed the consumption of ferrous [iron] sulfate from 80 to 100 % depending of: its stoichiometric consumption; pH environment from 2 to 4 during the regeneration of Cr⁶⁺ in the acid environment and from 7,5 to 9,0 in the alkaline condition. To alkalize the wastewaters we used the lime milk solution. Ferromagnetic particles are made from the steel DIN (WNr), mass is 150-250 g, diameter is 2,0-2,5 mm and l/d=10. Duration of treatment at the vortex layer is 0,5-1,5 c. Basic concentration of Cr⁶⁺  was changing from 100 to 1000 mg/dm³.

Another sterilization results of chromium-containing waste water by AVS-100

The results of industrial testing of AVS-100 show the high quality of treatment from chromium and heavy metals (Fe, Ni, Zn, Cu, Cd) on enterprises which clean chromium-containing wastewater in acid and alkaline conditions. At the same time consumption of reagents in installation AVS-100 is 90-100% of from stoichiometric consumption. Treatment facilities and their operation with using vortex layer of ferromagnetic particles are much simpler and efficient which is confirmed by our experimental investigations. Consumption of reagent such as additive (Ca(OH)2, Na2CO3 in the regular methods of treatment is on level 115-120% and consumption of reducing agent (FeSO4) is on level 150-175%.

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The transformer requires less care compared with other electrical equipment. The degree of maintenance and necessary inspection for its operation depends on its capacity, on the importance within electrical system, the place of installation within the system, on the weather conditions, and the general operating conditions. The normal expected life of a power transformer is about 35-40 years. Life of a power transformer essentially means life of its insulation system comprising mainly: a) Solid dielectric [paper, varnish, cloth, pressboard]; b) Liquid dielectric [mineral oil].

Failure of a transformer in the chain causes interruption in electricity supply and dislocation of all the works going on.

Damage to inside of coil winding stack of oil filled transformer

Internal causes of failure are

• failures of transformer insulation,
• failure of winding due to excessive heating,
• internal short circuits,
• failure of winding joints,
• ingress of moisture in the oil and insulation,
• deterioration of insulating oil, and
• failure of other auxiliary internal equipment,

such as reactor of the tap changer, contacts of the tap changer etc. As transformer oil ages, it oxidizes and begins to break down. The by-products of the degradation process include acids, aldehydes, and peroxides, which bind together to form sludge. Sludge attacks the cellulose insulation, inhibits oil flow, and traps heat inside the transformer. Eventually the dielectric gap is bridged, resulting in failure of the transformer.

Oil in addition to serving as insulating means serves to transfer the heat generated in the windings and the core toward the walls of the tank and the radiators. Because of this, it is required that it complies with the following characteristics:

• High dielectric breakdown
• Low viscosity
• Well refined and free of materials that they may corrode the metallic parts
• Be free of moisture and polar ionic or colloidal contaminants
• To have a low pour point
• Low flash point.

The insulating oil (transformer oil) deteriorates gradually with use. The causes are the absorption of the moisture from the air and foreign particles that get into the oil and start to cause oxidation. Oil is oxidized by the contact with the air and this process is accelerated by the increase in the temperature in the transformer and by the contact with metals such as copper, iron, etc.

In addition, the oil suffers a series of chemical reactions such as the decomposition and the polymerization that produces particles that are not dissolved in oil and that are collected in the coil and windings. These particles are called sediments. The sediments do not affect directly the dielectric breakdown, but the deposits that are formed on the winding hinder its normal refrigeration.

Certainly you can change transformer oil (insulation oil) but it`s cannot resolve the problems. Up to 10% of the volume of oil in the transformer is also entrapped in the cellulose insulation; this oil contains polar compounds and can ruin large quantities of new oil.

Changing the oil does not remove all the deposited sludge, especially those in the cooling fins, trapped in the solid insulation and in between the winding.

These residual sludges will dissolve in the new oil and trigger the oxidation process immediately.

Oil purification or degassing is also no longer effective, oil must be other change what the mostly do today or regenerated, what will be a perfect alternative. But you need to remember that regeneration does not replace purification, both of them is very important for transformer maintenance.

The difference between regeneration and purification is that purification cannot remove substances such as acids, aldehides, ketones, etc. in solution, and can therefore not change or improve the colour of the oil.

The regeneration process incorporates the thermo vacuum (purification) and fine filtration processes.

Regenerating the oil or other insulating medium in a transformer is probably one of the few environmentally beneficial alternatives that is also cost and productivity effective at point of delivery and over the lifespan of the equipment.

Regenerated transformer oil by GlobeCore  UVR 450/16 unit

Regeneration should be the first option to consider in any transformer maintenance program. The aim of a preventative transformer maintenance program is to remove the decay products from the oil before they cause damage to the transformer insulation system. A well-planned preventative maintenance strategy will prevent a wet core condition and ensure that the transformer always operates in the sludge free zone.

First of all, oil regeneration saves a lot of money. Regenerated oil might be better then what you are using now.

It may be noted that reconditioning by centrifugal separator or filtration does not remove the acidity from the oil but will remove only sludge, dust etc. and will tend to retard the process of deterioration. Only regeneration by filters with fuller`s earth will help to reduce the acidity in the used oil and in addition improve the resistivity.

The additional benefit of regeneration is it also works at its most effective whilst the transformer is energized and this also brings the benefit that there is no loss of productivity to the equipment that is fed by the transformer.

We present you a world new product – installation SMM-R (UVR) by PC Globecore. Now you don`t need disconnected transformer because our plant woks with energized transformer, as result – no money loss and no unsatisfied customers.

Today to keep regulators happy and customers and investors interested, you’ve got to demonstrate “green” and environmentally friendly initiatives. Our equipment can resolve this problem. Because in GlobeCore installation SMM-R (UVR) the sorbent that we use “Fuller’s earth” can be reactivated in the same system. Advantage of this technology is that you don’t need utilize exhausted sorbent, but you can use it 2-3 years without replacement. The best process for reclaiming transformer oil is treatment using Fullers Earth.

The Fullers earth can be reactivated 200 to 300 times before replacement is required. Oil can be processed continuously using the same charge of Fullers Earth. No disposal of oil soaked waste is required, greatly reducing the cost of operation.

SMM-R mobile oil regeneration systems are designed for the following processes:

• Fuller`s earth regeneration of transformer oil;
• Removal of solved oil decomposition products;
• Improvement of oil decomposition products;
• Improvement of oil`s color;
• Drying electrical equipment while purifying the oil;
• Removal of moisture from the oil to less than 5 ppm;
• Filtration with or without heating to 0.5 – 1 micron, (14/12 ISO4406) purity;
• Degassing to less than 0.1% volumetric gas content;
• Increase of oil`s breakdown voltage to above 70 kV;
• Initial filling of electric equipment with insulating oil;
• Pulling vacuum on transformers and other electrical equipment.

It is impossible to ensure reliability and longevity of energy systems without controlling the quality of transformer oil. Recent experience shows that approximately 30% of transformer oil, filled in power transformers, has deteriorated to the point when it becomes a risk factor. This is caused both to natural degradation of oil in operation due to thermal oxidation aging, and contamination with moisture and solid particles. The traditional array of test methods is not quite enough to ensure timely action to prevent the need to replace the oil. The most reliable method of determining the cause for oil aging and selecting the most suitable purification technology is to run a complex test using modern instruments and oil control procedures. Such complex approach to oil quality also allows revealing defects of the equipment in early stages of development.

 At present, more advanced methods of oil testing are coming into use, such as highly efficient liquid and gas chromatography, automated particle counting and membrane filtration, infrared spectrometry, electric strength measurement etc.

 Electric strength of transformer oil is determined primarily by its purity. Breakdown voltage is significantly affected by dispersed water and solid particles, which conduct electricity.

 The adverse effects of moisture on oil operation have been studied well and wide. However, the effects of particles depending on their size, quantity and origin require further research. Such research is nearly impossible without application of modern oil contamination control systems and instruments. Solid particle content can be determined by the weight methods, which are, however, time consuming and difficult, but do not allow to determine particle size and origin. A much better solution is to use automated particle counters in combination with membrane filtration lab. This allows to control purity class, which describes the dispersed phase in the oil, as per ISO4406.

 Determination of the contamination amount in oil as per ISO4406 is a powerful diagnostic tool, which allows control of not only the purification system’s efficiency, but also presence development of various defects in the electrical equipment. This method is much more informative, precise and quick, compared to the usual weight method.

Dielel fuel before and after regeneration by UVR plant

 As a rule, transformer oils contain a large amount of particles smaller than 10 micron. These particles are very mobile and can drift and concentrate in areas of strong electric field. As a result, field becomes uneven and further degradation of oil insulation reliability follows. Metal particles, apart from reducing electric strength, also increase catalytic influence on the oil’s aging through heat and oxidation. Purity class control allows diagnosing the condition of oil impregnated cellulose insulation of the equipment during operation.

 High efficiency liquid chromatography is one of the most dynamically developing analytical methods today. It is used to determine the content of furan derivatives and additives in transformer oil, increasing diagnostic accuracy. Derivatives of the pentatomic heterocyclic compound furan, are selective products of thermochemical destruction and aging of cellulose, which is a component of the oil impregnated paper insulation. The content, dynamic of formation and ratio are the criteria of insulation condition. If more than 15 mg of furan compounds are detected in the oil of operating equipment, regular and extensive monitoring of insulation degradation is required. Furfurol content can also be determined by express analysis, based on color reaction of furfurol with acetic anhydride.

 Content of Ionol additive is determined by IR-spectrometry; a double-beam spectrometer (Perkin-Elmer 283, Specord M80) can be used. IR-spectrometry allows obtaining information on additives, aromatic and acidic compounds content, and can indicate the oil’s type if required.

 Using IR-spectrometry in combination with high efficiency liquid chromatography facilitates solution of nearly all analytical problems, related to the need of identifying various chemicals in the oil. This can be very important when diagnosing electrical equipment.

 Thin-layer chromatography can detect the content of ionol additive. The TLC method is simple and inexpensive in terms of required equipment.

 Oil quality control can be improved in terms of efficiency and accuracy by determining the dependence of oil’s specific cubic conductance and tg delta on the oil’s temperature. Oil’s aging process results in increased content of polar compounds, acids and peroxides, water etc which leads to formation of colloid structures and sludge. Measuring volume resistivity of the oil, along with other electric tests, such as breakdown voltage and tg delta test increase efficiency of detecting hidden defects of a transformer or its bushings. The difference of volume resistivity between heating and cooling of the oil is common when colloid compounds are present in the oil.

 Implementation of chromatography labs for DGA increases accuracy of diagnostics and makes the analysis simpler and more efficient.

Transformer oil regeneration plant UVR by PC GlobeCore production

 An example of accuracy and extent of the above methods: a transformer was diagnosed in 1997; the process included a full scale physical and chemical analysis of the oil from the transformer’s tank and bushings.

 DGA indicated CO, CO2 and CH4 exceeding the limits, which is a sign of thermal defects of solid insulation. The high content of furan compounds and their distribution in the oil tank is indicative of paper insulation destruction and local thermal defect. Very large particles of glassine and varnish also indicated destruction of paper insulation and varnish cover of lamination stack.

 Diagnostics of another transformer the same year also yielded extensive results. DGA indicated that oil had been heated to 622C; no defect of the cooling system could have caused such temperatures. A thermographic test showed a possible steel burn-through in the lower portion of the magnetic system between phases A and B. A significant amount of metal particles was detected by membrane filtration.

A closer look at phase B showed, that the bushing’s condition was unsatisfactory. The oil was nearing the limit of contamination content; the membrane filtration method showed presence of regular spherical metal particles in the oil; such particles can only be formed by electric discharge or arc.

 Tg delta was unacceptably high (20%), besides, an abnormal change of Tg delta with temperature was detected (tan delta was 0.5/2.2/20% at 20/70/90⁰C respectively).

 The conclusion of the diagnostic was that the oil aging was accelerated and colloid conglomerates were being formed. Phase B bushing had to be replaced.

 The above shows that modern methods of oil quality control combined with traditional diagnostic methods can significantly increase accuracy and efficiency of complex electric equipment tests.