JPH03135456A - Ionized wire in electrostatic precipitator - Google Patents

Abstract

PURPOSE:To protect the core wire of tungsten by a single plating layer or multi plating layers of platinum, rhodium, palladium or their alloys and to drastically prolong its disconnecting service life by forming the plating layer (or layers) on the surface of a tungsten wire having specified wire diameter into a specified thickness. CONSTITUTION:The ionized wire 1 is formed by forming a single plating layer (or multi layers) 5 of platinum, rhodium or palladium on the surface of a tungsten wire 3 having 50 to 200 mum wire diameter into 0.3 to 9 mum thickness. In this case, its disconnection is suppressed because the tungsten wire is protected by the plating layer of platinum or the like. Furthermore, the tungsten wire can be transformed into the one having the diameter thinner than that of a conventional one, by which corona starting voltage can be reduced as well s power consumption can be reduced. Moreover, platinum, etc., can be formed thinly to a degree because they form a plating layer, so that the ionized wire can be manufactured extremely at a low cost even though platinum, etc., are expensive.

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field) This invention relates to an ionization line in an electrostatic precipitator,
More particularly, it relates to ionizing radiation that can significantly extend cutting time.

(Prior art) In order to remove fine dust from the air passing through the dust collector, an electric dust collector is equipped with an ionization wire and a plate-shaped counter electrode facing the ionization wire. There is.

Then, the ionization wire is connected to the positive side of a high voltage DC power supply, and the counter electrode is connected to the negative side, and the corona discharge between the two electrodes is used to charge the dust, and the charged dust is collected. It is configured to be collected into a collector.

Conventionally, a relatively thick tungsten wire with a diameter of about 200 μm has been used as the ionized wire to take into account breakage due to issues such as tensile strength, not stretching even under long-term tension, and good corrosion resistance. has been done. but,
Corrosion progresses in tungsten wire as well, and its disconnection life is not very long.

Therefore, we conducted an experiment using stainless steel wire, which has good corrosion resistance, but the wire breakage life could not be improved much. In addition, when conducting experiments on wires made of various materials, it was discovered that a clad wire in which a tungsten wire is coated with platinum has a significantly longer disconnection life.

(Problem to be solved by the invention) In an electrostatic precipitator, when a clad wire in which a tungsten core wire is coated with platinum is used as an ionization wire,
It was discovered that corrosion is less likely to occur and wires are less likely to break. The clad wire is produced by covering the tungsten wire with platinum and bonding it tightly, and then using a hot drawing method, so it has excellent coverage and adhesion.

However, in manufacturing clad wires, both interfaces are sufficiently indented, so if the thickness of the platinum layer becomes thin, the above intrusion may not be sufficient and the adhesion of the platinum layer may become insufficient. be. Therefore, in order to obtain sufficient adhesion, the platinum layer cannot be made very thin, and the platinum layer needs to have a total weight of about 25%, generally 25 to 40%, for example 0. The average thickness of the platinum layer in a clad wire of .5φ is about 35 μm.

That is, in the clad wire, there is a problem that the thickness of the platinum layer is relatively thick compared to the diameter of the tungsten core wire, and the wire is expensive.

[Structure of the Invention] (Means for Solving the Problems) This invention was made in view of the conventional problems as described above. One or more plating layers are formed, and the thickness of the plating layer is 0.3 μm to 9 μm.

(Function) According to the above structure, since the tungsten wire is plated with platinum, rhodium, or palladium, the plating layer can be extremely thin to about 0.3 μm to 9 μm.

That is, since it is based on plating, the platinum layer can be made extremely thin compared to the thickness of the platinum layer in the clad wire, for example. Further, the tungsten wire is protected by a platinum plating layer, and can have the same effect as a clad wire.

(Example) Referring to FIG. 1, the ionized wire 1 according to this example is made by plating a platinum layer 5 on the surface of a tungsten core wire 3 with a diameter of 80 μm using a normal plating method. The thickness of the plating layer 5 was approximately 5 μm.

In order to compare the ionized wire 1 with the above configuration, a tungsten wire, and a stainless steel wire, the wire diameters of each (80
Electrical dust collectors 7A, 7B, and 7C of the same structure are placed side by side outdoors as shown in Figure 2, with the same conditions such as length, tension, and number of tubes, and are approximately three times the normal operating conditions. The electrostatic precipitators 7A, 7B, and 7C were continuously operated simultaneously under severe conditions in which a current was applied, and the time required for all ionization wires in each electrostatic precipitator 7A, 7B, and 7C to be disconnected was measured.

As is clear from FIG. 3, the tungsten wires A to I are
98,142,76.112°124.13 respectively
2.90,377.108 hours, and in the case of stainless steel wire, 110,110.122.88,122
．． It was 88,120,140.86 hours. In other words, in the case of tungsten wires and stainless steel wires, the lifespan is approximately 120 hours, whereas with ionized wires made of platinum-plated tungsten wires, there was no breakage even after continuous operation for more than 2,000 hours. Ta.

Figure 3 shows the data for an example of a disconnection test when the plating layer is approximately 5 μm thick.As a result of various tests, pinholes occur when the plating layer thickness is less than 0.3 μm, and platinum The effectiveness of plating decreases. In addition, if the thickness of the platinum plating layer becomes thicker, the price will only increase and no significant improvement will be seen effectively, so the thickness of the platinum plating layer should be approximately 0.3 μm to 9 μm. is desirable.

Further, when tests similar to those described above were conducted on rhodium, palladium, which belong to platinum metals, and an alloy containing 20% rhodium and 80% platinum, similar effects were obtained. Note that since rhodium is extremely expensive compared to platinum and palladium, it is desirable to use platinum or palladium as the plating layer.

[Effects of the Invention] As can be understood from the above description of the embodiments, in the present invention, the ionization wire in the electrostatic precipitator is coated with platinum, rhodium, , palladium or an alloy thereof, and the thickness of the plating layer is 0.3 μm to 9 μm, so the tungsten core wire is protected by the plating layer. As a result, corrosion of the core wire can be suppressed and the life of wire breakage can be significantly extended.

In this case, since platinum or the like is a plating layer, it can be formed extremely thin, and although platinum or the like is expensive, it can be manufactured at a relatively low cost.

Furthermore, since the tungsten wire is protected by a platinum plating layer and wire breakage is suppressed, the tungsten wire can be made smaller in diameter than before, lowering the corona starting voltage and lowering power consumption. It can also produce effects such as:

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is an explanatory diagram showing the configuration of an ionization line, FIG. 2 is an explanatory diagram of test conditions, and FIG. 3 is an explanatory diagram of test results.

Claims (1)

[Claims] One or more plating layers of platinum, rhodium, palladium, or alloys thereof are formed on the surface of a tungsten wire with a wire diameter of 50 μm to 200 μm, and the thickness of the plating layer is 0.3 μm to 9 μm. An ionizing beam in an electrostatic precipitator characterized by: