DE1961055A1 - Feed cable for electrostatic precipitators - Google Patents

Description

Cable and Met a Il works 1-1034

Gutehoffnungshütte Aktiengesellschaft December 4, 1969

Feed cables for electrostatic precipitators

The invention relates to a feed cable for electrostatic precipitators, which consists of a conductor, an insulation surrounding the conductor and an outer protective sheath.

Supply cables for electrostatic precipitators are not only subject to normal direct voltage stress, but also to constant stress from impulse voltages that are triggered by arc discharges in the filters. Due to reflection processes, these pulses can superimpose so unfavorably that considerable voltage peaks occur. This® type of stress means that the cables used up to now, in which the conductor is made of copper tape around a core of several layers of paper wound around a wire, which in turn is surrounded by paper insulation and an outer protective sheath, only have a very short lifespan. The reason for the failure test is essentially the steep flank and the - H8b @ of the pulses * D & uurch passing through the cable. they form considerable local stress gradients, iaaerfaalib ü & T insulation, which, especially since the charge can remain in the layered Dielekirifoa », ultimately lead to the destruction of the cable.

It is the object of the invention to find an edible char oil for electrostatic precipitator systems that has a lifetime and is also easier to manufacture . © ti »ißli © si material. Ijoateht,

10Sa24 / 2006- ■ - * -

on which a layer of plastic made weakly conductive and over it an insulation made of a thermoplastic plastic is applied. This construction according to the invention creates a cable that lasts much longer. In the conductor according to the invention, the impulses are dampened by the high inductive resistance of the ferromagnetic material, so that impulse peaks which arise from the superimposition of reflected impulses are avoided. By the force applied to the conductor S _e hicht of conductively homemade plastic damping of the pulses is still favored as il driven by Stromverdränguag the k ©© hfrequenten shares of pulses for the most T _e in the conductor smoothing, where de due to "high resistance of fäXättwjmgsselaicht is »= strongly dampened, that is, the steep ones. The edges of the impulses are flattened. The insulation made of thermoplastic plastic also creates a homogeneous dielectric, which prevents the charge from getting stuck, as was the case with the well-known paper-insulated cables.

Used as conductor material, steel is expedient, 'it could, but also. His & sl, Sebalt © the ferromagnetic alloys - to be used * In particular, if it is taa foodJsssbel for. larger K electric filter systems act ₉ - becomes a head TCrwendsn, who aua e ± H.®sa -aus © isiselnen miifc = ·

Stranded StafeldrSfeton formed rope ordered = »The flexibility s © l © fe © r laile is much greater than with M && B ± v®n L-eit © ra gl © ic & GB Qu © ro © nni" tte. As material for «Si © Isolisriasüg Verisresadet ss-a »v @ rt®ilhaft PoIy that has cheap © ©! © Istrisoto © properties to

1Q9824 / 2006 *

The invention is explained in more detail on the basis of an exemplary embodiment shown schematically in the figure.

The figure shows a section through a feed cable for electrostatic precipitator systems 2 the conductor smoothing, with 3 the insulation, with 4 the shielding and 5 denotes the outer protective jacket. The conductor 1 consists of a rope formed from individual steel wires twisted together. On the ladder 1 is a layer 2 made of a copolymer of polyethylene, which is made weakly conductive with carbon black or metal powder. This line smoothing 2 covers unevenness on the conductor surface, which lead to increased field strengths and thus to increased stress on the Isolation 3 would result. Above the ladder smoothing 2 the insulation 3 is angeodnet, which consists of polyethylene and continuously injected with the help of an extruder will. The shield is located above the insulation 4, which shields the field of conductor 1. To protect against external mechanical damage, the cable is surrounded by an outer protective jacket 5, which is a metal jacket, a metal reinforcement or a plastic jacket, for example, made of polyvinyl chloride.

When operating such feeder cables, which have a direct current voltage source, for example a rectifier with the electrostatic precipitator constructed similarly to a plate capacitor electrically connect, voltage pulses often occur in the cable, which have the following cause; Between the plates of the electrostatic precipitator, of which the one connected to the positive pole of the DC voltage source, the other earthed, creates an electric field. Dust-

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particles that are carried between the plates, for example the powdery components of Exhaust gases are now charged and each time they collect on the plate, which corresponds to the type of charge.

If now the percentage of dust particles on the plates If a certain limit value is exceeded, bridges can form over which a discharge can take place. The resulting voltage pulse travels in the cable further, is reflected, so that it is reflected by summing create higher impulses which then destroy the cable.

This cannot occur with the feed cable according to the invention. The fact that the conductor 1 consists of a ferroraagnetic Material consists, the impulse is attenuated more strongly than in a conductor, for example made of copper, because a ferromagnetic material has higher inductances. Another possibility to dampen the impulses offers Layer 2, which is made weakly conductive. The skin effect causes the high-frequency components of the pulse pushed into the outer edge zones of the conductor 1 and, since the layer 2 has a much higher resistance, steamed there. Increased voltage peaks, which could destroy the insulation 3, therefore no longer occur.

109824/7006

Claims (4)

Kabel- u η d M e t a 1 1 ν e r k e 1-1034 Gutehoffnungshütte Aktiengesellschaft k. 12. 196 ° claims 1. Feed cable for electrostatic precipitators, consisting of a conductor, an insulation surrounding the conductor and an outer protective jacket, marked by Λ a conductor made of ferromagnetic material on which a layer of plastic made weakly conductive and an insulation made of a thermoplastic material is applied over it. 2. Feed cable according to claim 1, characterized in that the conductor consists of steel, 3. Feed cable according to claim 1 or 2, characterized in that the conductor consists of one of each with each other consists of stranded steel wires formed rope. 4. Feeder cable according to claim 1 or one of the following, characterized in that the insulation is made of polyethylene consists* 109824/2006 Lee rs e i-th