Electrostatic Oiler is a successful example of the application of liquid electrostatic spray, it is a set of electromechanical and high-voltage electrostatic technology of high-tech products. It relies on the role of high-voltage electrostatic spray liquid anti-rust oil evenly on the surface of the metal plate with material can be widely used in the process of material production line of steel and non-ferrous metal plate with , as well as other high quality oiled. Knife beam and steel plate between Dangtu oil knife beam is connected to the high voltage DC power negative, on the establishment of a high-voltage electrostatic field. Generating corona discharge phenomenon due to oil coating of the edge of the knife beam is relatively sharp, very small radius of curvature at the tip of the knife beam, the air molecule is ionized in this case the positive and negative ions, these positive and negative ions along the electric line rapid movement positive ions fly injector knife beam is neutralized, negative ions positively charged and flew to the steel plate, the way and the oil droplets collided leaving the oil droplets charged were electric field acceleration.
|Published (Last):||14 March 2005|
|PDF File Size:||6.82 Mb|
|ePub File Size:||11.49 Mb|
|Price:||Free* [*Free Regsitration Required]|
Oiling has been conventionally made by contact system brushes, rollers, pads or spraying system airspray or airless spray. Contact systems are always affected by the uneven flatness of the surface which causes uneven film thickness or dry stripes. Spraying systems are always associated with a more or less pronounced overspray which impairs the deposition rate, polluting in the same time the working site.
Moreover the oil deposited by conventional means is free flowing from the sites of coils severely contaminating storage floors. In both cases oil consumption is well over the theoretical - often even three or four times as much and the uniformity of the coating obtained is very poor.
We shortly remember the principles of electrostatics for the readers which are not familiar with this type of application. Electrical charges of the same name repel each other, electrical charges of opposite name attract each other. Moreover fluid filaments or drops immersed in a strong electric field undergo the electrostatic pressure and break out in ever smaller electrically charged droplets which repel each other creating a finely atomized fluid mist.
This mist when opposed to an earthed surface is attracted and evenly settles and firmly adheres on this same surface. In practice the fluid mist is negatively charged and the metal surface is kept at ground potential connecting it to the mass, which is very easily done due to the presence of large metals structures in every process line.
The deposited droplets loose immediately their electric charge so that no evidence of the electrostatic deposition process is left on the coated surface. As a result a minumum of energy is used to atomize the oil, through a keen study of every constructive detail to avoid current losses with great advantage for the safety of operation. The opposite polarities electrostatic charging system we are now proposing as standard avoids over oiling the strip edges and greatly reduces the escape of oil mist from the enclosure pass line windows.
A two blade electrostatic oiler for continuous strips is basically made as follows see 1 e 2. The oil is gravity fed through a filter to the suction port of our exclusive closed loop circulating system including a pump, a throughflow electric heater and a duplex fine filter.
Which such a system a very small quantity of oil is quickly heated to the working temperature T2 of e. The oil is then fed under low pressure to the metering pumps and sent to the oiling blades which are heated at temperature T3 by circulation of an independent heating fluid.
The oil flow is accurately controlled by the oiler PLC. The output of the metering pumps candy optionally controlled by precision flowmeters mounted downstream of the metering pumps reaching a new standard of precision for this class of machines.
The oil to be applied enters the A cavity of the blade and overflows from a range of small holes 6 drilled flow throught the blade wall reaching the shatp edge 3 Fig. In such a way a better viscosity control and costant fine automisation of the oil are obtained. As it is know when the temperature increases both the viscosity and the surface tension of the oil lower and the atomisation il highly improved.
With this blade design it is possible to apply very viscous products or sometimes products wich are solid at room temperature. The excess oil particulary when the strip is narrow compared to the blade length is collected in a bottom sump provided with levels and then the sucked in by a recovery pump, filtered and recirculated to the storage oil tank. IThe yield of the oil is therefore near to the theoretical value and there no pollution or effluents treatment problems.
For safety, mechanical protection and good housekeeping the blades are mounted in a suitable enclosure fig. The enclosure is provided with clear inspection doors interlocked with the high voltage source and with the oil feeding pumps. The side walls of the cabin are lined with highly insulating plastic plates wich act as electrostatic refectors. Special insulating fenders or plates protect the blades against accidental strip impacts.
When single coil instead of continuos strip are to be oiled the enclosure is equipped with a suitable threading table wich makes possible the passage of the strip head through the cabin and then it is automatically retracted or folder down.
Threading tables are normally driven by air cilynders. When it is not possible to fit on the line a standard enclosure many special designs studied for the special job are available.
Example of special design are enclosures for the Temper mills where very little space is normally available on top of the recoiler, and a very high oil output is requested.
The enclosures can be made stationary or extractable from the line running on suitable rail driven by a brake gearmotor. The industrial frequency operated oil filled conventional generators employing selenium rectifiers and big capacitors require strong currents, up to 2 mA. Therefore at the maximum rated voltage of kV a W power is involved. With the most modern electronic generators the same results are obtained employing ma 0.
Moreover because of a much lower capacity of the system the energy stored and released in case of a spark is much lower. The electronic generators are made by a control panel usually mounted into the machine control desk and a "cascade" where the high voltage is generated normally mounted on top of the enclosure. The shielded high voltage cables are therefore wery short and do not cross the working site with a great safety advantage.
Moreover it is possible to install special automatic earthing device to quicky discharge the residual charges whenerver the generator is turned off. Using these devices it is no more necessary to discharge the blades from their residual charge with an earthed probe before touching them for maintenance or cleaning.
The provided block and alarm circuits render the use of these generators extremely safe. We supply a standard two generators, one for each blade to take advantage of the much profitable opposite polarities systeme: drastically reduce oil mist escaping from the enclosure and no overoiling of the strip edges. We offer now four different electrostaic atomiser types to suit a wide range of application:. The rules of selection are generally flexible and the best type of atomiser fot the application to hand would usually be assed on a one-to-one basis.
In any case oil flows from the atomiser in form of cuspid wich under the effect of the electrostatic pressure break in tiny droplets forming a curtain of very fine oil mist. The blade edge is formed as a single plane, externally wetted from a row of holes uniformly spaced along the blades body. There are several advantage with this design. The orifice dia is about 10 times wider than the conventional slot blade which is virtually self cleaning and mantenance free. The topsite blade is fitted with a non conductive insulating mask to limit the current drain within 50 microAmps.
The atomising edge of the underside blade is twice the length of the topsite blade to ensure the highest possible atomising density and transfer efficiency and is designed specifically to overcome the "flooding" common with conventional slot blades. These blades are heated by circulation of an indipendent diathermic fluid through two channels drilled through the two halves of their steel body.
Astonishing performance are obtainable with this type of blades. TURBODYN rotating bell units First developed for use as a paint applicator for automotive manufacturers, the system has been modified to apply extremely low oil quantities to ferrous and nonferrous strips. Normally the atomised oil produces a circular pattern on the strip of approximately mm effective diameter, with up to three atomisers positioned each side of the strip. As a first in this field the bells revolutions are electronically controlled.
The system is ideal for application of very low coating weights of DOS or similar products normally required on Tin-plate, Black-plate and Aluminium lines. PNEUMODYN airspray units Manufactured again by our Elettrospray Division, these atomisers are a development of conventional electrostatic painting guns and may be used for high output applications typical of Temper or Skin-Pass lines or to coat individual sheets immediately ahead of a press.
These are ideal tools for use at a typical Temper Mill where there is a big improvement over the conventional contact absorbent roller most often used in this situations and where a very high oil output is required.
In every case the atomisers are connected by means of a special High Voltage cable to a HV generator. An Operator Panel displaying status of functions and alarms is supplied as standard. Flow control or monitoring can be provided optionally but is not considered to be essential to the performance of the machines and set a new standard of automation in this class of machines.
The Advanced Automation system can be interfaced to upper level computers when required via Profibus, Interbus and similar network systems.
Electrostatic Oiler Blade System
Manufacturer of standard and custom electrostatic automatic oilers for the metal processing industry. Products include blade systems, rotary atomizers, and temper mill oilers. Available with a variety of features. Oilers can be designed with C-frame design, telescopic blade carriers, enclosure heating, removable tank heaters, and solid-state power supplies. Suitable for use in pickle line, galvanizing line, temper mill, slitting, inspection, and blanking line applications.
Electrostatic Oilers Suppliers
Oiling has been conventionally made by contact system brushes, rollers, pads or spraying system airspray or airless spray. Contact systems are always affected by the uneven flatness of the surface which causes uneven film thickness or dry stripes. Spraying systems are always associated with a more or less pronounced overspray which impairs the deposition rate, polluting in the same time the working site. Moreover the oil deposited by conventional means is free flowing from the sites of coils severely contaminating storage floors.
Terronics electrostatic oilers provide a better way to oil steel strip for rust protection, lubrication, or stamping. Most existing methods are ineffective and cause oil handling headaches. Mechanical methods of oil deposition rolling, dripping, pumping, blade wiping as well as most semi-electrostatic methods are imprecise and require over-oiling to ensure total strip coverage. TDC's electrostatic oilers deliver the most uniform targeting and control of oiling possible. Improves Safety and Housekeeping - Precise targeting and control eliminate overspray and reduce hazard and mess of oil runoff from coils, both for rolling mills and their customers. Reduces Customers Oil Disposal Problems - Less oil applied means that your customers pay less to remove and dispose of oil.
How Electrostatic Oilers Work