DE3415984A1 - ELECTRIC FILTER - Google Patents

Description

Te'e'on: (02 21) 23 83 48 Telegrams: Marspatsnt Telex no. 8 332 336

Kl / Hb / we April 16, 1984

Hugo Petersen Ges. For procedural engineering Anlagenbau mbH SCoKG Dantestrasse 4-6, D-6200 Wiesbaden

Electrostatic precipitator

The invention relates to electrostatic precipitators with tubular or plate-shaped collecting electrodes and toothed spray electrodes.

It has long been known for the separation of floating bodies of all sizes, including the finest mist and dusts, to use electrostatic precipitators with differently designed precipitation and spray electrodes.

With the approaches known in the prior art to solve the problem, maximum separation efficiency even during removal Achieving the finest particles from gas streams has so far been the focus of attention looking for an optimal design of the spray electrode profile .

For example, from GB-PS 840.853 tubular electrostatic precipitators Precipitation electrodes and spray electrodes in the form of toothed strips are known. It is also known, spray electrodes in the form of toothed bands that are twisted around their longitudinal axis (AT-PS 121.928). One more way the design of the spray electrodes is shown in DE-AS 1.201.816. Tape-shaped spray electrodes are used here used with sawtooth-like spray tips where the spray tips of the tape are opposite to each other are bent at a certain angle from the plane of the tape and in addition another sharp-edged Have a kink on the same side.

The object of the invention is to improve the separation efficiency of electrostatic precipitators with toothed spray electrodes to improve further.

This object is achieved according to the invention in that Electrostatic precipitator with tubular or plate-shaped collecting electrodes and centrally arranged toothed spray electrodes are provided, their ratio of the distance

(r) of the spray tips from the central axis in the case of tubular precipitation electrodes or the central plane between plate-shaped electrodes Collecting electrodes to the distance (R) of the central plane or central axis from the walls of the collecting electrodes is between 0.35 and 0.7. The ratio r / R is preferably between 0.4 and 0.6 5.

The surprising finding that by adhering to the dimension ratio r / R specified above, reproducible highly efficient electrostatic precipitators are accessible preferably apply to electrostatic precipitators whose toothed, band-shaped spray electrodes can be rotated around their central axis are twisted. An alternative preferred embodiment of the electrostatic precipitator according to the invention is strip-shaped Toothed spray electrodes, which by bending the teeth from the belt plane to a three-dimensional

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Bodies have been reshaped.

The design feature of the invention, 0.35 - r / R ^ 0.7, which conditionally independent of the optimal separation behavior of the electrostatic precipitators designed according to the invention on the absolute dimensions of the electrostatic precipitator and the cross-sectional geometry tubular collecting electrodes.

Possible embodiments of the invention are in Drawing and are explained in more detail below:

It shows:

Fig. 1 shows the cross section of an electrostatic precipitator with a tubular Precipitation electrode (5) with a hexagonal base, the toothed spray electrode (6) with spray tips (1,2,3 and 4) is provided, which are bent 45 ° forwards (1,3) or backwards (2,4 ^.

Fig. 2 shows the cross section of an electrostatic precipitator with a square Plan view of the collecting electrode (5); the spray tips (1,3) of the spray electrode (6) are 45 ° behind at the front, the spray tips (2,4) are bent 45 ° backwards.

Fig. 3 shows the cross section of an electrostatic precipitator with a circular Floor space. 1, 2, 3, 4, 5 and 6 have the same meaning as in the previous figures.

Fig. 4 shows a plate electrostatic precipitator with arranged in parallel Precipitation electrodes (5) and toothed spray electrode (6) bent outwards by 45 ° (1,3) and back (2,4) Spray tips.

5 shows the for all types of electrostatic precipitators shown above Applicable schematic side view of the electrostatic precipitator opened perpendicular to the collecting electrode walls (5)

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with centrally arranged spray electrode (6). 1 / 2.3 and represent the spray tips described above.

The effect of the distance ratio r / R on the separation efficiency (expressed by the quotient of the particle migration speed w and the maximum particle migration speed w is represented by diagram I (page 7). In this diagram the values w / w are plotted for tubular lowering electrodes and various toothed spray electrodes (produced either by twisting the toothed spray electrode belt or by bending the teeth out of the plane of the belt). The points entered are measured values; the curve drawn represents the compensation curve.

The diagram shows that w / w of 50%

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at r / R = 0.3 to 100% at r / R = C, 49 and at r / R = 0.66 reaches the 50% value again.

The following examples explain the invention and show that electrostatic precipitators with optimum separation efficiency can be achieved according to of the invention can be obtained regardless of the special design of the collecting electrode.

Example 1 :

In a tubular electrostatic precipitator with cylindrical tubes as collecting electrodes, which had an inner diameter of 300 mm, different ones were made Toothed belts, spray electrodes made by twisting or bending the teeth are used teeth of different lengths, calculated from the central axis of the spray electrode.

The electrostatic precipitator was subjected to an air flow

suggests that the sulfuric acid mist with an average particle size of 0.5 μΐη contained. With the same air speed and the equally applied voltage were the following percentages as a function of the tooth length (r) Migration speeds (w / w) get:

Max

r (mm) 45. 54 68 78 90 98 ^{W / W} max ⁽ ' S) 50 83 97 100 78 60 r / r (1) 0.3 0.36 0.45 0.52 0.60 0.65 R-r (mm) 105 96 82 72 60 52

Ex iel 2:

In a tubular electrostatic precipitator as described in Example 1 Kind, however, with an inner tube diameter of 250 mm, the operation was under the same specific Conditions run as in example 1, the results are as follows:

r (mm) 45 54 68 78 ^w / ^w max ^ ' ) 73 88 100 81 r / r (1) 0.36 0.43 0.54 0.62 R-r (mm) 80 71 57 47

From these results it can be seen that the ratio: ^ nis r / R and not the distance of the tooth tips of the spray electrode from the central axis or the distance the tip of the tooth of the spray electrode from the closest The collecting electrode wall is the determining parameter for the relative migration speed.

Example 3:

In a plate-type electrostatic precipitator with a plate spacing of 200 mm, the same electrodes were used as in Example 1. According to the deviating definition

tion of r (here the distance between the spray tip and the imaginary center plane between the two parallel plate electrodes) In comparison to the aforementioned Examples 1 and 2, the absolute values differ for r.

The test procedure corresponded to the procedure described in Example 1. The following results were achieved:

r (ram) 34 34 41 41 51 51 59 59 68 68 74 74 w / w (%) 67 85 97 100 45 35 r / r O, 0, 0, 0, O, 0,

The results show the same tendency as the values obtained with tubular electrostatic precipitators. The maximum however, w / w is shifted to slightly higher values of r / R.

Claims (4)

Godfather η 'tan sayings 1. Electrostatic precipitator with tubular or plate-shaped precipitation electrodes and centrally arranged toothed spray electrodes, characterized in that the ratio of the distance (r) of the spray tips from the central axis for tubular precipitation electrodes or the distance (r) of the spray tips from the center plane between the plate-shaped precipitation electrodes to the distance (R) the median plane or central axis is between 0.35 and 0.7. 2. Electric filter according to claim 1, characterized in that the ratio r / R is between 0.4 and 0.6 5. 3. Electrostatic precipitator according to Claims 1 and 2, characterized in that they contain toothed, band-shaped spray electrodes which are twisted by being rotated about their longitudinal axis. 4. Electrostatic precipitator according to Claims 1 and 2, characterized in that they contain toothed strip-shaped spray electrodes which have been shaped into three-dimensional bodies by bending the teeth out of the plane of the strip.