JPS60251920A - Gas scrubbing apparatus - Google Patents

Abstract

PURPOSE:To smoothly perform the recirculation of catalyst, in a gas scrubbing apparatus, by providing a receiving part between a packing material and a scrubbing solution storage tank and providing the precipitative separation tank communicated with the receiving part while communicating the bottom part of the separation tank and the storage tank through an opening and closing valve. CONSTITUTION:Exhaust gas is sent in a scrubbing tower 2 from a blower 4 to receive gas-liquid separation treatment in a packing material 1 and exhausted to the open air while mist therein is removed by a demister 5. A scrubbing solution is flowed down to a storage tank 6 and a part thereof is flowed into a receiving part 15. The scrubbing solution of the storage tank is flowed into a separation tank 16 and the catalyst contained in said solution in a suspended state is precipitated and separated while the supernatant solution is flooded to be flowed out to the outside. The catalyst accumulated in the separation tank is appropriately returned to the storage tank under its own wt. by the opening and closing of a valve 17. The reduction of scrubbing water by the flooding from the separation tank is replenished by water from a tap 18 and the liquid level is always kept constant.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for cleaning gas in a cleaning tower using a cleaning liquid containing a catalyst in a concentrated state.

Gas cleaning devices bring specific components in gas into gas-liquid contact through a filler in order to absorb them into a cleaning liquid, and are generally widely used for deodorization, exhaust gas cleaning, and the like. For example, some deodorizing equipment uses an alkaline aqueous solution as a cleaning liquid to clean foul-smelling gas from a human waste treatment tower, absorb hydrogen sulfide in the gas, and remove it through an alkaline reaction. Some cleaning solutions contain a catalyst in a concentrated state to increase absorption efficiency.

These are caused by the accumulation of oxidation products of substances absorbed in the cleaning liquid, and if the cleaning gas is dry, the water in the cleaning liquid evaporates, concentrating dissolved substances, such as calcium and magnesium. It becomes easier to generate scale. For this reason, it is necessary to add make-up water so as not to increase the concentration rate and discharge the dissolved substances in a rich manner. Since this discharged cleaning liquid contains a catalyst and the like as a hydration brake, various measures have been taken to collect and reuse the catalyst and discharge it as supernatant water without hydration.

An example of the conventional method is as shown in FIG.
The cleaning liquid is jetted down from the spray nozzle 3 at the upper part of the cleaning tower 2, which is equipped with a cleaning tower 2, and the gas to be cleaned is sent from the lower part into the cleaning tower 2 by the blower 4, and the cleaning gas is brought into gas-liquid contact with the cleaning liquid in the packing material 1. After removing the accompanying mist with a demister 5, it is released into the outside air. On the other hand, the washing water from the filler 1 flows down to the storage tank 6 at the bottom of the washing tower 2, and is sent to the spray nozzle 3 by the slurry pump 7. Based on the value, the washing water is sent to the alkaline concentrate 10 or via the pump 11 by the regulator 9. The washing water is appropriately flowed into the washing tower 2 and the pH of the washing water is adjusted.

In addition, in order to prevent malodorous components or oxidation products of malodorous components from accumulating in the cleaning solution, a certain amount of make-up water 12
is added, and the added amount of cleaning liquid flows into the adjacent settling tank 14 from the lower opening 13 of the storage tank 6 and overflows from the upper part.

In this conventional example, since the side surface of the sedimentation separation tank 14 is sloped, the flow of the liquid here becomes slow, and the flow rate becomes slower as it goes to the top. There is.

However, the storage tank 6 and the separation tank 14 have a lower opening 13.
Therefore, there is a problem in that the catalyst accumulated at the lower part of the storage tank 6 flows into the separation tank 14 together with the flowing water, becomes large in quantity, and flows out together with the 'IA ML water without settling. That is, there is a problem in that smooth sedimentation and separation cannot be performed.

Furthermore, a method has been devised in which a sedimentation separation tank is provided separately from the washing tower, and the cleaning liquid that has overflowed the storage tank 6 flows into this separation tank to sediment and separate the catalyst.

However, in this case, it settled in the separation tank.

The catalyst has a wide range of M degrees, and its thick slurry must be returned to the washing tower 2 using a pump, which complicates the operation and has the drawback that the concentration of the suspended catalyst in the washing liquid fluctuates greatly. In addition, there are also disadvantages that not only the operation but also the equipment becomes complicated and the installation area becomes large.

The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a gas cleaning device that can perform smooth sedimentation and separation of a catalyst, and can smoothly circulate the sedimented catalyst to a cleaning tower using its own weight. .

In order to achieve this object, the present invention provides, in the above-mentioned conventional gas cleaning apparatus, a receiving part that receives a part of the cleaning liquid flowing down from the filling material, between the packing material in the cleaning tower and the lower cleaning liquid storage tank. At the same time, a sedimentation tank and separation tank are provided on the side of the washing tower that communicate with the receiving part, and the bottom of this separation tank is located above the bottom of the storage tank marked Kj, and an opening/closing valve is installed between the bottom of the separation tank and the storage tank. It was communicated via.

With this configuration, gas cleaning is performed by gas-liquid contact as in the conventional case, and most of the cleaning liquid from the filler flows down into the storage tank, and a part of it flows into the receiving part.

The washing water that has flowed down into the storage tank is circulated in the same manner as described above, and the suspended catalyst in the washing water that has flowed into the separation tank is sedimented and separated, and the supernatant liquid overflows and flows out to the outside. The catalyst deposited in the separation tank is appropriately returned to the storage tank by its own weight by opening and closing the valve.

Therefore, according to the present invention, the washing water is partially taken out and the catalyst is separated by sedimentation in an independent sedimentation separation tank.
This function is reliably carried out, the amount of catalyst leaking out along with the discharge stream is extremely small, and since the separated catalyst is returned by its own weight, the operation is easy.

Embodiments of the present invention will be described below with reference to FIG. 2 of the accompanying drawings. Note that the same reference numerals as above indicate the same items.

As shown in the figure, in the above-mentioned gas cleaning device, a receiving plate 14 extending obliquely upward is provided on the inner wall of the cleaning tower 2 between the filling material 1 and the storage tank 6, and a box receives a part of the cleaning gas that is being washed away. A receiving portion 15 is formed on the outer wall of the tower-2.
A sedimentation separation tank 16 is provided which communicates with the receiving part 15, and the cleaning liquid flowing into the receiving part 15 is guided to the separation tank 16, the catalyst is sedimented and separated, and the supernatant water can flow out from the overflow weir 20. Separation tank 16
The amount of supernatant water that flows out depends on the height of the overflow weir 20 and the height of the top of the receiver 14'.

If a current plate 17' is provided between the receiving part 15 and the separation tank 16,
Smooth sedimentation separation is performed without mixing the supernatant liquid with the suspended washing liquid in the receiving part 15.

The separation tank 16 is provided so that its bottom surface is higher than the bottom surface of the storage tank 6, and the bottom part is communicated with the storage tank 6 through an on-off valve 17. When the on-off valve is opened, the sedimented catalyst is stored by its own weight. It can be returned to tank 6.

A pole tap 18 is provided in the piping of the make-up water 12, and the tap 18 is used to maintain the liquid level at a constant level during ``field''.

The sedimentation separation tank 16 has an inclined side wall as shown in the drawing, which is advantageous in terms of the catalyst sedimentation effect.

If the storage tank 6 is provided with an aeration device 19, the aeration prevents the catalyst from settling and accumulating, and the catalyst concentration in the wash water is kept constant.

The embodiment is constructed as described above, and its operation will be explained below.

As in the past, when the gas to be cleaned is sent into the cleaning tower 2 by the blower 4 while the cleaning liquid is jetting down from the spray nozzle 3, the gas to be cleaned is mixed with the cleaning liquid and gas liquid in the packing material 1. After the mist is removed by the demister 5, it is released into the outside air.

On the other hand, the lower part of the cleaning liquid from the filler 1 flows down into the storage tank 6, and a part flows into the receiving part 1b. The washing water that has flowed down into the storage tank 6 is circulated in the same manner as described above, and the suspended catalyst in the washing water that has flowed into the separation tank 16 is sedimented and separated, and the supernatant liquid overflows and flows out to the outside. The catalyst accumulated in the separation tank is removed from valve 1.
By opening and closing 7, it is appropriately returned to the storage tank 6 by its own weight.

Preferably, this valve 17 is an automatic opening/closing valve that opens and closes at constant intervals of 1i41.

Furthermore, since the washing water decreases due to overflow from the separation tank 16, water is supplied through the tap 18, and the liquid level in the storage tanks is always kept constant.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a conventional gas cleaning device, and FIG. 2 is a schematic diagram of an embodiment of the scum cleaning device of the present invention. 1...Filling material, 2...Washing tower, 6...Storage tank, 15
... Receiving part, 16... Sedimentation separation tank, 17... Opening/closing valve. Patent applicant: Kubota Iron Works Co., Ltd. Agent: Kama 1) Statement D Figure 1 Figure 2 Cleaning gas ↑

Claims (1)

[Claims] In a device that performs scum cleaning by 71 stages of cleaning that wraps the catalyst in a localized state in a cleaning tower containing a filler, there is a space between the filler in the cleaning tower and the lower cleaning liquid storage tank from the filler. A receiving part is provided to receive a part of the washing liquid flowing down, and a sedimentation separation tank is provided on the side of the washing tower and communicates with the receiving part, and the bottom of this separation tank is located above the bottom of the storage tank, and A gas cleaning device characterized in that a tank bottom and a storage tank communicate with each other via an on-off valve.