JPH0317547B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a cleaning tower, at least one cleaning liquid spray nozzle located on the cleaning tower axis, and a corona electrode assembly located above the spray nozzle, wherein the cleaning The column relates to a device for removing dust from industrial waste gas by treating it with a cleaning liquid consisting mainly of water, having an upper raw gas inlet and a lower pure gas outlet and a wet scrubber.
The washing tower is upright within the scope of the invention because of the primarily vertically arranged flow channels in which the purification of the gas stream takes place by washing. A plurality of individual spray nozzles or a plurality of aggregations of spray nozzles can be arranged one above the other on the washing tower axis. Wet cleaning refers to a cleaning process in the area of the spray nozzle and a subsequent wet separation of the dust. It is clear that the cleaning water can also absorb gaseous components. The washing tower may be equipped with a ring gap washer. The expression corona electrode belongs to the technology of electric filters (see Rüger, "Lexicon, der, Farfreens Technique", Vol. 16, 1970, p. 119).

According to principle, electric filters are cylindrical or plate capacitors. Between the electric field electrodes, approximately 20,000 or
DC voltage of 70000V and above is applied,
This voltage is usually generated from an alternating current or three-phase alternating current power supply network by means of a high-voltage transformer and a rectifier. The negative side of the rectifier output terminal is connected to corona electrodes with the smallest possible radius of curvature, from which the electrodes emerge. In most cases, corona electrodes are made of relatively thin wires, often with barbs and sometimes with a rectangular cross section. The positive pole of a DC power supply is generally grounded, and the collecting electrode is also grounded. However, in principle, the polarity may be reversed. Within the framework of the invention, as usual, the corona electrode is connected to the negative side of the rectifier output terminal, and the electrodes around one are grounded. However, within the scope of the invention it is also possible to operate with reverse polarity. The process in an electric filter is the same as that of a self-sustaining discharge, where current flows from a corona electrode to an electrode of opposite polarity. The raw gas is
Passes between the electrodes. The entrained dust particles or dust-fine liquid droplets are mostly negatively charged and move toward the collection electrode in a typical corona electrode assembly. These particles release their charge here and are ejected. In devices such as those mentioned at the outset, which are well known from experience, the corona electrode assembly is part of an electrical filter, in which a collecting electrode surrounds the corona electrode. The aggregate as a whole has sufficient length to also allow evacuation at the collection electrode after the dust has been charged. This is followed by a wet cleaner. In this respect, two dust removal devices are being integrated into a unit.

The object of the present invention is to provide the apparatus mentioned at the beginning so that the corona electrode assembly and the wet cleaning device are functionally integrated to perform purification, and to improve the dust removal efficiency, particle size limit, and degree of dust removal. It's about improving.

In order to solve this problem, the present invention shows the following. In other words, the cross-sectional area of the cleaning tower is configured to match the raw gas flow rate of 5 to 30 m/sec, preferably 5 to 15 m/sec, taking into account the above-mentioned parts, and the corona electrode assembly is configured to match the raw gas flow rate in the direction of the raw gas flow. The washing tower, which has a corona electrode with a length of 14 to 40 cm, preferably 15 to 20 cm, and a polarized electrode around it and has no other parts, performs the separation in the area of the spray nozzle and below it.
According to an advantageous embodiment of the invention, the cross-sectional area of the washing column and thus the entire device is configured for a raw gas flow rate of approximately 10 m/sec, while the length of the corona electrode is approximately 15 cm. Then it is advantageous. Also within the scope of the invention, corona electrodes with 20,000 or more
Driven to a corona voltage of 70,000V, preferably approximately 45,000V.

In particular, there are many possibilities for variations and improvements within the scope of the invention. According to an advantageous embodiment of the invention, the corona electrode assembly consists of a plurality of closely grouped tube sections, for example a plurality of hexagonal tube sections arranged in a honeycomb manner, which tube sections are connected to the source gas. is arranged in the direction of flow and is connected as a polarizing electrode, and a corona electrode is arranged on the axis of the tube section.
According to another proposal of the invention, which is particularly important because of its good separation effect, the tube section is made of metallic material and serves as a collecting electrode. The spray nozzle within the scope of the invention is a so-called swirl pot nozzle consisting of a cylindrical nozzle casing, preferably with a tangential inlet for the cleaning liquid, the spraying being effected by a swirling effect. If the washing tower has a ring gap washer, according to the invention the corona electrode assembly is arranged before the ring gap washer in the direction of flow. According to a preferred embodiment, the corona electrode assembly is arranged after the at least one spray nozzle in the direction of flow, so that a gas saturated with water vapor is present in the corona electrode assembly and in the annular gap washer. It is now ready for implementation. The corona electrode assembly may be movable relative to the ring gap washer.

The present invention is based on the following knowledge. Thus, it is not necessary to configure the corona electrode assembly in such a way that electrical filtering and dust separation occur at the collecting electrode. The parts surrounding the corona electrode are therefore only polarizing electrodes, which are necessary for electrostatic reasons. These polarized electrodes can cooperate in dust separation, but the charged dust mainly remains charged and reaches the wet cleaner where it carries out the normal cleaning process. Surprisingly, the dust removal efficiency, separation limit particle size, and degree of dust removal are
Overall it's much improved.

The above numerical parameters of the invention ensure that according to the invention charging of the particles to be separated occurs in the corona electrode assembly, but no separation of the particles occurs. The separation of the charged particles only takes place in the area of and below the subsequent atomizing nozzle, where a surprising separation is achieved. That is, the above numerical parameters are adjusted depending on the flow rate of the gas to be purified so that there is virtually no contact between the particles to be separated and the polarized electrode, and in that sense, they have a unique effect. ing.

Embodiments of the present invention will be described below with reference to the drawings.

The apparatus shown in FIGS. 1 to 3 is used to remove dust from industrial waste gas by treating it with a cleaning liquid mainly consisting of water. A gas stream to be purified flows through the device. In its basic structure, the device includes a cleaning tower 1, a plurality of cleaning liquid spray nozzles 2 arranged on the cleaning tower axis 3, and a corona electrode assembly 4 arranged above the spray nozzles 2.
Consists of.

As is clear from FIG. 1, the cleaning tower 1 has an upper raw gas inlet 5 and a lower pure gas outlet 6. Here the gas flows from top to bottom.

The cross-sectional area of the washing tower is configured, taking into account the components already mentioned, to provide a raw gas flow rate of 5 to 15 m/sec. Advantageously, the flow velocity is approximately 10 m/sec. The corona electrode assembly 4 has a corona electrode length L of 15 to 20 cm, preferably 15 cm, in the direction of the raw gas flow. The cleaning tower 1, which has no other parts, has in this example a polarized electrode 8 in the region of the corona electrodes 7 and surrounding these corona electrodes. In this embodiment, the negative pole 9 of the DC power supply
may be connected to the corona electrode 7, while the positive electrode 10 may be grounded and connected to the polarized electrode 8. The corona electrode 7 is driven with a corona voltage of 20,000 to 70,000V, preferably approximately 45,000V. In particular, as is clear from a comparative consideration of FIGS. 2 and 3, the corona electrode assembly 4 is made up of a plurality of tube sections 8 closely grouped as polarized electrodes, for example, hexagonal electrodes grouped in a honeycomb shape. It consists of a tube section 8. The tube section 8 is arranged towards the direction of raw gas flow. A corona electrode 7 , configured for example as a needle electrode, is arranged in the axis of the tube section 8 . Pipe section 8 handled in this example
are made of metallic material and are additionally used as collecting electrodes and are connected. The spray nozzle 2 is configured as a pivoting pot nozzle.

In the embodiment according to FIG. 4, the washing column 1 has a different construction. Spray nozzles 2 for the cleaning liquid, which mainly consists of water, are arranged on the cleaning column axis 3 .
After the spray nozzle 2, an adjustable built-in member 12
There is a ring gap washer 11 having a ring gap cleaner 11. A corona electrode assembly 4 is arranged in front of the ring gap washer 11 in the direction of flow. The corona electrode assembly 4 can be connected to a high voltage power supply as mentioned at the beginning.

The cross-sectional area of the washing tower is configured to provide a gas flow rate of 5 to 15 m/sec. The corona electrode assembly 4 has a corona electrode length L of 12 to 20 cm in the direction of gas flow and additionally has a polarized electrode 8 surrounding the corona electrode 7. The separation takes place in a ring gap washer 11 which is constructed in the usual manner and is therefore connected to earth. In this example, the configuration may correspond to an advantageous embodiment of the invention, the cross-sectional area of the flow channel being approximately 10 m/
sec, and the corona electrode assembly 4 has a corona electrode length L of approximately 15 cm. The corona electrode assembly 4 is behind the two spray nozzles 2 in the direction of flow. These spray nozzles are arranged in such a way that they can introduce a gas containing dust and saturated with water vapor into the corona electrode assembly 4 and the ring gap washer 11 . At least one further spray nozzle 13 may be arranged after the corona electrode assembly 4 in the flow direction.

[Brief explanation of drawings]

1 is a longitudinal sectional view of the device according to the invention;
The figure is an enlarged view of part A of the apparatus in FIG.
3 is a sectional view along the line A--A of the device of FIG. 2, and FIG. 4 shows a further embodiment of the device according to the invention corresponding to FIG. DESCRIPTION OF SYMBOLS 1...Cleaning tower, 2...Spray nozzle, 4...Corona electrode assembly, 5... Raw gas inlet, 6...Pure gas outlet, 7...Corona electrode, 8...Polarization electrode.

Claims (1)

[Claims] 1. The cross section has a flow velocity of exhaust gas of 5 m/sec or more.
a cleaning tower configured to provide a speed of 30 m/sec;
an exhaust gas inlet provided at the head of the cleaning tower; a cleaning gas outlet provided at the bottom of the cleaning tower;
It has at least one cleaning liquid spray nozzle arranged on the axis of the cleaning tower and a corona electrode assembly arranged above the spray nozzle, the corona electrode assembly forming a honeycomb shape forming a polarizing electrode. a corona electrode having a plurality of hexagonal tubular sections grouped together and surrounded by grounded tubular closely spaced polarized electrodes, which polarized electrodes extend from 15 cm along the direction of the exhaust gas;
extending over a length of 20 cm, characterized in that the corona electrode is activated with a corona-forming voltage of approximately 45000 V, and the spray nozzles are a plurality of pivoting pot nozzles arranged below the axis of the corona electrode assembly. A device that removes dust from factory exhaust gas by treating it with a cleaning solution mainly consisting of water. 2. At least one ring gap washer with an adjustable built-in member is arranged after the spray nozzle in the direction of flow, and a corona electrode assembly is arranged before the ring gap washer in the direction of flow. , and is arranged after the at least one atomizing nozzle in the direction of flow, so that a gas saturated with water vapor can be introduced into the corona electrode assembly and into the ring gap washer. .