JPS61178020A - Apparatus for absorbing exhaust gas - Google Patents

Abstract

PURPOSE:To increase an absorbing speed by performing the recirculation of an absorbing solution at a sufficiently high speed, in an inverted scrubber, by enclosing a gas-liquid contact part and the absorbing solution reflux pipe from a tower top in an absorbing tower. CONSTITUTION:Exhaust gas is introduced into an absorbing tower 2 from a blower 1 and contacted with the absorbing solution, which is blown up from an absorbing solution storage tank 4 by air blow pressure, in a gas-liquid contact part 3 having a Venturi throat, a perforated plate and a packing material to remove the harmful component in the gas while the treated gas is receives gas-liquid separation treatment in a gas-liquid separation chamber 5 and exhausted from the outlet 8 of the absorbing tower 2 through a demister 7. The absorbing solution is flowed down from the gas-liquid separation chamber 5 by the absorbing solution reflux pipe 6 enclosed in the absorbing tower 2 to be returned to the absorbing solution storage tank 4.

Description

[Detailed description of the invention]

The present invention relates to an exhaust gas absorption device. Conventional wet-type exhaust gas absorption devices include a parallel-flow type and a counter-current type in which the exhaust gas and absorption liquid are allowed to flow. In a counter-current exhaust gas absorption device, the absorption liquid flows in the opposite direction to the flow direction of the exhaust gas, and harmful components in the exhaust gas are absorbed and removed through gas-liquid contact mechanisms such as packing, perforated plates, and venturi throats. It's a method. The parallel flow type exhaust gas absorption device is a method in which an absorption liquid is caused to flow in the same direction as the exhaust gas flow, and harmful components in the exhaust gas are removed through the above-mentioned gas-liquid contact mechanism. As a result of the fact that the amount of gas to be processed in a co-current absorber is generally larger than that in a counter-current absorber, the equipment cost is significantly lower than that in a counter-current absorber. Also, among the co-current absorption devices, there are absorption devices in which the absorption liquid is blown up to the top or bottom of the tower by the blowing pressure of exhaust gas, or is sucked and blown down. Since there is no liquid transfer pump, the footprint of the device is significantly smaller. Although the method of the present invention also belongs to the co-current type absorption apparatus, it has been devised by further advancing the features of the co-current type absorption apparatus. In the absorption apparatus of the present invention, the absorption liquid is transferred to the penturi sq-seat, perforated plate, and
Packing materials, etc.Although the absorption liquid is blown up to a certain gas-liquid contact part, the absorption liquid separated into gas and liquid in the gas-liquid separation chamber at the top of the absorption tower does not flow out of the absorption tower, but instead flows into the absorption liquid reflux system installed inside the absorption tower. It quickly refluxes into the absorbent reservoir through the tube. The structure in which the absorption liquid reflux pipe does not come out of the absorption tower is a feature of the present invention. In the apparatus of the present invention, the absorption liquid is circulated sufficiently quickly, so that the harmful gas absorption rate is high and the absorption tower itself is compact. In addition, in the absorption device of the present invention, as with the conventional parallel flow type absorption device which occupies the smallest device area, there is no need for a pump, so the space occupied by the pump and pump piping is not only unnecessary.
Since the absorption liquid reflux pipe does not exit the absorption tower, the space occupied by the device is smaller than that of any conventional absorption device. This is important when installing an exhaust gas absorption device. In many cases, there is only a small allowable space for installation, not only in chemical factories, but also in chemical laboratory fume hoods, septic tanks in housing complexes, shops, etc. When the device is incorporated into a device such as a fume hood, it is important that the reflux tube for the absorption liquid is not exposed to the absorption medium, which is a feature of the device of the present invention. The present invention will be explained with reference to the drawings. Exhaust gas is introduced into the absorption tower (2) by a blower (1), and is blown from the absorption liquid storage tank (4) by blowing pressure at the gas-liquid contact area (3), which has a venturi throat, perforated plate, packing, etc. Harmful components are removed by contact with the rising absorption liquid,
Gas and liquid are separated in the gas-liquid separation chamber (5), and the absorption liquid is returned to the reflux pipe (6).
The liquid flows down and returns to the absorption liquid storage tank (4). The exhaust gas passes through a demister (7) and is discharged from the absorption tower outlet (8).

[Example 1] Draft exhaust gas containing 300 sulfur dioxide gas was sent at a gas flow rate of 10 m/sec using three stages of perforated plates as a gas-liquid contact device, and 1% sodium carbonate was used as the absorption liquid to measure the liquid-gas ratio. As a result, the sulfur dioxide gas removal rate was 99.8% when operated at 0.51/m.

[Brief explanation of the drawing]

The figure is a schematic diagram of the absorption device.

Claims (1)

[Claims] In a normal inverted scrubber, exhaust gas is introduced from the side of the gas absorption tower and from the lower part of the absorption tower, the absorption liquid is blown up by the blowing pressure of the exhaust gas to the Venturi throat, perforated plate, and packing installed inside the absorption tower to bring them into gas-liquid contact. An exhaust gas absorption device characterized in that an absorption tower includes a contact portion and an absorption liquid reflux pipe from the top of the tower.