1 ZLA Series Double-stages Vacuum Transformer Oil Purifier Transformer Oil Purification ZLA series double-stage vacuum transformer oil purifier is particularly suitable for dehydration, degasification and purification process of insulating oil. It is developed and produced to treat varieties of insulting oils with different kinematic viscosity and flash point. As ideal equipment, it is widely used in industries of power generation and transmission, mining, transportation and manufacturing etc. to purify different kinds of insulating oil and other low viscosity lubricating oils. The double-stages model is much more efficient than single-stage vacuum oil purifier. Application ZLA series is designed according to vacuum dehumidification principle, separation technique, precise filtration and many other patented techniques. It completely abides by national standard DL/T521-2004 and especially suitable for purifying all kinds of unqualified insulating oil. It s widely used to purify varieties of insulating oil applied in all kinds of electrical equipment s, especially the fine purification treatment of high grade new oil, imported oil and super-voltage transformer oil for quickly eliminating the polar material, mechanical particles, moisture, light hydrocarbon and acetylene. ZLA series can be used for online operation in over 110KV transformers, especially event at high-latitude areas. It also can be used as drying equipment for a variety of electric facilities. And it is widely used for oil filling for transformers and circuit breakers under vacuum condition. Structure & Features Three-dimension Flash Distillation System Importing the technologies from some famous brands like German HERING, American PALL and Japanese KATO, this system consist of Three-dimension Vacuum Flash Evaporation Chamber, Flash Pall Ring, Semi-circular Sprayer and Flash Evaporation Plate etc. It can deeply remove the water and gas from the oil. In this system, the oil has been fully thin filmed by Flash Pall Ring (the thickness of thin film is 0.025mm. In increases the oil exposing area in the vacuum). Therefore, the gas and water can get enough evaporation time to accomplish the best effect of degassing and dehydration. In this way, the water content and gas content of the oil can reach the product standard quickly. The system can help the whole system purify the oil more efficiently and have stronger capability of emulsification and dehydration. The tester of vacuum degree is Pirani gauge (measured by Pa), which is much more accurate than common vacuum meter and whose performance is very stable.
2 High Speed and Large Throughput Double-Stages Vacuum System The system adopts-stages vacuum system (vacuum pump + roots pump) to get a high vacuum status. The vacuum pump is originally from German LEYBOLD, which can reach the max limit of vacuum quickly. It owns many merits like tight structure, slim size, low noise and low vibration etc. It s also installed with an internal check valve to stop the oil from backward. The vacuum system has a defoamer device, which can prevent the oil from entering the front pump and avoid the oil leaking, so it can prolong the cycle life of vacuum pump and roots pump. The vacuum pump takes the natural cooling type. The forward is installed with a check valve to prevent the oil reflux, which can contaminate the transformer oil. Foam Level Detector and Defoamer Device Adopting high-sensitivity liquid level controlling system, it can control the oil level in the vacuum flash distillation chamber automatically and ensure the oil level to adjust at a proper range by itself, in hence, the oil leaking will be avoided. By assembling the defoamer device, it can turn the occurring foam and bubbles efficiently to oil liquid and return the vacuum chamber quickly. Oil Pumping System Imported Component-Oil input pump, original German SIHI, is a kind of selfabsorption and bypass pump. It s also a kind of vane impellor, or so called Centrifugal composite system. It brings a low remaining of air etching, ensures the machine work normally even if the transformer is in vacuum status. It also brings some merits like even oil flowing, without pulsation, high efficiency, low noise, without vibration, well self-absorption, well sealing and long cycle life etc. The motor selects ABB brand, the oil input pump uses double liquid level protection system, which could stop rotating automatically if the oil level is overflowed. Filtration System Precise multi-stage filtration system makes a high precision reinforced stage by stage. The filters adopted have large capacity of containing pollutants and are able to eliminate the mechanical particles in the oil effectively. Firstly the oil goes through a magnetic filter to get rid of metal grains and tiny metal particulates. The magnetic filter is made of permanent magnet and stainless steel net, which only needs to be washed but not replaced during permanent usage. After dehydration, the treated oil will finally go through the fine filter for further precise filtration. The fine filter adopts German ARGO filter element, which is with high filtration precision ( 1000), corrosion resistance and good mechanical strength while the cycle life and safety of the filter is much better than others. Finally the size of rest particulates in the finished oil is 1µm, the cleanliness matches the level NAS6. Heating System Our electric heating system adopts unique design and process. It has some merits like heating evenly, keeping oil temperature constant, heating quickly and without dead area etc. The heating elements locate at the protection pipe where there is 1cm air gap between them. The heating component directly heats the protection pipe via are, then the protection pipe heats the oil indirectly, that ensure the oil flow heating at surface evenly without any dead area so as to avoid over-heated in partial area. The range temperature control can avoid a frequent start of temperature detector if the oil reaches preset temperature, which can prolong the cycle life to the utmost. The design of heating system is automatic in protecting it from dry heat, absolutely forbidden heating without oil. Heating system, vacuum system and oil drainage system are integrated and combined with each other. Only after starting the vacuum pump and oil pump, the heating system can start, in hence to avoid a damage to the equipment due to a over high oil temperature.
3 Electric Controlling System Electric Controlling System is designed according to IEC standard, whose main electric components are from French SCHNEIDER brand, which stable performance can ensure the equipment work continuously and also makes the operation and safety protection more humanistic. It s very easy to operate the controlling panel some of whose buttons of power switch on/off, Vacuum pump start/stop, oil pump start/stop, heating start/stop are with LED showing lights. There also has digital temperature meter, vacuum meter and pressure meter etc. The pressure protection function can cut off the power automatically if it s over loaded and this technique reaches national standard. It is equipped with chain safe protection system, which ensures the machine to work automatically for a long time. The interaction of oil pump and heater can cut off the heating power automatically if the oil output pump stop working suddenly; the interaction of vacuum pump and heater can make sure the heater start to work unless some oil has already come into the heater after opening the vacuum pump. By adopting digital temperature controller, the performance is more stable. It can preset the min and max temperature limit, to avoid a frequent opening of heater and prolong the working life. The arrangement of wire circuit is very reasonable and well-ordered in the electric Control cabinet, and the outer cables routine the PVC pipe to get a safe protection. Multi-protection System The machine is equipped with fine protection system and with very high automation level. By the interaction and combination of relevant components, it accomplishes the motor protection (overload, over current and default phase), over-high voltage protection, double temperature protection, no oil protection and wrong operation protection etc. As a result, it can avoid any regular accident. The system will alarm automatically when meeting problem. Double Liquid Level Controlling System. Double Liquid Level Controlling System High-sensitivity ball float liquid level controlling is able to control the oil level in the vacuum flash distillation chamber automatically. The oil pump shall stop itself from empty rotation when the oil is in low level. On the contrary, the oil pump shall automatically output the oil and stop input when it s in high level. Any way, it gets a simple operation and genuinely let the machine free form worker s supervision. Instruments The instruments adopted include liquid level meter, vacuum meter, platinum resistance, digital temperature controller and electric contact pressure meter. The grade of the instruments is above IP55. Both instruments and adjustment devices ensure the accuracy of testing and reading. Vacuum inspection: vacuum meter Double oil temperature control: digital temperature controller Oil temperature supervision: Pressure supervision: Electric Contact Pressure Meter The high/low oil level control in vacuum flash distillation chamber: liquid level controlling system and Solenoid Valve. The adjustment of vacuum degree in vacuum flash distillation chamber: air-liquid balanced valve. The pressure of output oil from oil pump: Electric Contact Pressure Meter Whole machine protection: the whole machine shall stop working if any mistake occurs. Oil sampling: It makes more convenient to take the oil from sampling port for analysis.
4 External Design This equipment is designed according to ergonomics. All parts are accurately set within a person s movable range. The filter element uses quick detached type so as to get a convenient replacement. All above is in pursuit of a high working efficiency and a low working intensity. External/Internal Optimization Treatment The whole machine is with mobile structure and no scratch on the surface. The whole connection is very tight and the welding area is without any overlap, burr and rusty spot. The connecting area adopts special sealing material with multilayers inspected by crack detection. The external painting is treated by four procedures: pickling (rust cleaning), nitrogenation (rust proof), spraying and baking. The surface becomes very smooth after spraying treatment and gets the resistance of oil corrosion. The internal painting is treated by three procedures: phosphorization, deactivation and then using German Polyamine ester to paint the internal surface evenly. It can avoid the increase of metal particulates from internal oxidation, therefore, it can ensure the oil not suffer internal contamination. Before dispatch from factory, all external/internal pollutants like dusts, painting spots have been cleaned completely, we can make sure the external painting not crack, not dye and not erode corrosively within 30 years. High quality sealing material is oil resistant (acrylonitrile-butadiene rubber), which has good sealing function and long lifetime. After the whole assembling the machine also should pass the strict seal test oil pressure test or oil filling test. Vacuum air pumping and Vacuum oil filling This machine is very suitable for working on site without power off. It can also dehumidify and carry out vacuum air pumping, vacuum oil filling and hot oil recycling to the electric equipments. It can satisfy the vacuum pumping and vacuum oil filling of transformer when assembling or inspecting it on site. Advanced Separation Technique > Magnetic separation technique to remove metallic particulates from oil > Vacuum distillation technique to break emulsion and remove water and light hydro carbon material > Evaporation separation technique to remove air and gases from oil > Pressure filtration technique to remove solid particulates from oil > Liquid film fine filtration technique to remove micro impurities from oil
5 Operation Principle When oil purifier begins to work, firstly the oil goes through a magnetic filter because of vacuum suction. It s able to get rid of large grains of mechanical particle and metal dust. The treated oil will enter the three-dimension flash distillation chamber after heated by heating system. The oil is atomized by the spraying device and sprayed into the three-dimension flash distillation Pall Ring. As a result, it forms a thin film (the thickness is 0.025mm). The film curve moves downward and creates a large exposing area as well as a long time holding process. So that it get a sufficient separation process of demulsifying, dehydration and degassing. The mixture of distilled steam, light hydrocarbon and other gases comes through water-gas separation device, strong wind condensation system and vacuum buffer. After experiencing a quick cooling. Steam and some condensable gases have been drained through drainage valve as condensed fluid while the rest incondensable gases have been drained through vacuum pump. At last, the treated oil which has been eliminated water, gas will be bumped into the second filter and fine filter for the precision filtration, the micro particulates will be removed if it is bigger than 1µm. By then it will finish the whole purification. Safety Protection Systems > Temperature protection > Oil level protection > Motor overload protection > Motor over current protection > Motor default phase protection > Over-voltage protection > Over pressure protection > Power failure protection > Oil input failure protection > Anti-foam protection