TW546159B - The scrubber waste air treatment system and related method - Google Patents

Abstract

A scrubber waste air treatment method is provided for treating the particles and acidic gas, which comprise to input the hardness softened scrubbing liquid to the scrubber; adjust the pH of scrubbing liquid over 10.5 by adding reagent; introduce the waste air into the scrubber; w a s h the waste air completely with the scrubbing liquid to remove the particles and acidic gas; exhaust the clean air to open air from the gas outlet of the scrubber. The method can enhance the remove efficiency of pollutant and save the waste air treatment cost by raising the pH of scrubbing liquid over 10.5 to increase the reaction for the weak acidic gas. It also employed the water softening apparatus to provide the hardness softened scrubbing liquid without calcium ion and magnesium ion, which can avoid forming the calcium hydroxide and magnesium hydroxide in the scrubber.

Description

546159 V. Description of the invention (1) Field and domain of the invention The present invention relates to an exhaust gas treatment system, and more particularly to an exhaust gas treatment system for a scrubber tower. Prior technology The process exhaust gas produced by general industrial processes usually includes toxic substances and has an odor. If the exhaust gas is not properly treated, it will cause air pollution. In addition, if the concentration of toxic substances in the exhaust gas exceeds the limit set by regulations, it may endanger the health of factory employees and the general public. In order to control air pollutants, air pollution prevention equipment must be used to treat the exhaust gas so that the concentration of toxic substances in the exhaust gas is lower than the limit set by regulations. One of the commonly used air pollution prevention equipment in the industry is the scrubber exhaust gas treatment system. The general scrubber exhaust gas treatment system treats exhaust gas by liquid washing. First, the strip washing liquid is introduced into the washing tower and then washed; the strip liquid circulation pump is transported to the top of the tower and enters the washing tower from the top of the tower. Then, the washing liquid is uniformly sprayed through the spraying device and returned to the bottom of the tower, and then is sent to the top of the tower by the washing liquid circulation pump to form a cycle. On the other hand, the exhaust gas is introduced into the washing tower from the bottom of the tower, then flows upward and contacts the washing liquid, so that the pollutants (such as particles, acid gas, etc.) in the exhaust gas are dissolved in the washing liquid, and the purified gas is passed from the tower Top drain. Because the washing liquid comes with many impurities after coming into contact with the exhaust gas, it is necessary to replenish the clean washing liquid into the washing tower and discharge the dirty washing liquid. For Xiexian: tower exhaust gas treatment system, due to the washing; the larger the contact area between the stripe liquid and the exhaust gas, the better the exhaust gas washing effect of the stripping tower, so the stripping tower usually needs to be designed to have a large liquid surface area and Lowest gas pressure loss

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I 546159 V. Description of Invention (2) In order to achieve the above-mentioned purpose, some packing materials are usually packed in the washing tower to increase the liquid-gas exchange area. The packing materials have many different shapes and have their unique surface area for designers to choose. Common fillers such as Raschig ring and Bell saddle ring. Generally speaking, the exhaust gas treatment system currently used in the industry is to concentrate the exhaust gas discharged from each equipment end according to the acid-base characteristics, and then directly treat it with several scrubber exhaust gas treatment systems. However, with the expansion of equipment and production capacity, the waste exhaust gas generated at the equipment end has also increased significantly, which has exceeded the original designed capacity of the washing tower. The consequent result is that the process exhaust gas is not properly treated and escapes to in the air. The conventional improvement technology is to install a local washing tower (1 oca 1 scr u b be r) on the machine side to reduce the content of process waste gas by wet washing or activated carbon adsorption, and finally discharge it to the wet washing tower. However, due to the limited space and cost, not every factory is suitable for installing a partial scrubber tower to improve the efficiency of exhaust gas treatment. In addition, the conventional improvement technology is to increase the amount of circulating water to reduce the concentration of acid gas in the circulating water, but it will increase the load on the pure water system and wastewater treatment system, and cause the plant water recovery rate to drop sharply and the plant water discharge rate to rise sharply. And the cost of water has increased dramatically. SUMMARY OF THE INVENTION In view of this, an object of the present invention is to provide an exhaust gas treatment system and method for a scrubbing tower, which can effectively remove the acid gas in the exhaust gas and improve the effect of the exhaust gas washing bar.

9954twf.ptd Page 7 1 546159 Μ V. Description of the invention (3) The purpose of the present invention is to provide an exhaust gas treatment system and method for a washing tower, without installing a local washing tower and without increasing the circulating water volume of the washing tower It can improve the washing effect of exhaust gas and save the cost of waste treatment. The present invention provides an exhaust gas treatment system for a washing column. The system is composed of a washing tower, a washing liquid supply device, a soft water device, a washing liquid circulation pump, a dosing device, and exhaust gas. It is composed of an injection pipe and an exhaust pipe. The washing liquid supply device is connected to the washing tower to supply the washing liquid into the washing tower; the water softening device is provided between the washing tower and the washing liquid supply device to soften the washing liquid supplied by the washing liquid supply device and send it Into the washing tower; the washing liquid is pumped back and forth to connect the bottom and the top of the washing tower, so that the washing liquid can be circulated in the washing tower; the medicinal device is connected to the washing tower, and the pH value of the washing liquid in the washing tower is greater than pH 1 0.5 or more; the exhaust gas injection pipe is connected to the washing tower, so that the exhaust gas is introduced into the washing tower; the exhaust gas discharge pipe is connected to the washing tower, so that the gas treated by the washing tower is discharged to the atmosphere. The invention uses a dosing device to adjust the pH value of the washing liquid in the washing tower to be above pH 0.5, and the acidic gas can fully react with the strong alkali within the reaction time, so that the removal rate of hydrogen chloride can be reduced from 82% ~ 95% is increased to 100%, and the removal rate of hydrogen fluoride is increased from 39% to 91% to about 9 9. 9 3%, which completely solves the problem of sour taste. However, when the pH value of the washing solution is raised to more than 10.5, the calcium ions and magnesium ions contained in the washing solution will form scales such as calcium hydroxide and magnesium hydroxide with hydroxide ions. Attaching to the inside of the washing tower causes fouling, and causes the inside of the washing tower to be blocked, causing the internal pressure difference to rise. Therefore, the present invention sets a soft water between the washing liquid supply device and the washing tower.

9954twf.ptd Page 8 546159 V. Description of the invention (4) Device for removing calcium and magnesium ions contained in the washing solution. Under the condition that the pH value of the washing liquid is adjusted to more than 10.5, the efficiency of the exhaust gas treatment is improved, and the washing tower can be smoothly operated without scaling. Moreover, the present invention does not need to install a local washing tower and increase the water consumption, but only needs to set a set of water softening device to improve the efficiency of exhaust gas treatment, thereby saving costs. The present invention also provides a method for treating exhaust gas from a washing tower. This method involves injecting a softened washing liquid into the washing tower. Then add medicament to the washing tour: adjust the acid value of the strip washing solution to be greater than ρ Η 10.5 or more in the tower, and inject the exhaust gas into the washing tower. Next, the exhaust gas and the washing liquid are thoroughly mixed to be removed. After the particulates and acid gas in the exhaust gas are discharged, the gas after the washing liquid treatment is discharged. In the present invention, the acid test value of the washing liquid is increased to 10.5 to increase the acid-base neutralization effect on the exhaust gas, and the soft water device is used to remove the calcium ions and magnesium ions contained in the circulating washing liquid, which can be avoided Fouling inside the washing tower can improve exhaust gas removal efficiency. Because the present invention does not need to install a local washing tower and increase the water consumption, only a set of water softening device can be used to improve the efficiency of exhaust gas treatment, so the cost of exhaust gas treatment can be saved. In order to make the above-mentioned objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below in conjunction with the accompanying drawings to make a detailed description as follows: Symbols of the drawings: 100: washing tower 1 0 2: washing liquid supply device

9954twf.ptd Page 9 i 546159 V. Description of the invention (5) 104 Soft water device 106 Washing liquid circulation pump 108 Dosing device 110 Exhaust gas injection pipe 112 Exhaust gas discharge pipe 114 Exhaust gas 116 Washing liquid 118 Washing liquid spraying device 120 Filling material 122 Acid Test Detector 124 Medicine Example Figure 1 shows a scrubber exhaust gas treatment system according to a preferred embodiment of the present invention. Please refer to FIG. 1. The exhaust gas treatment system of the washing tower of the present invention is at least a washing tower 100, a washing liquid supply device 10, a soft water device 10, a washing liquid circulation pump 10, and a dosing device 10. 8. The exhaust gas injection pipe 1 10 and the exhaust gas discharge pipe 1 12 are configured. The washing tower 100 includes a tank which provides space for the exhaust gas 11 4 to come into contact with the washing liquid 1 16. Common types of washing towers 100 are, for example, packed towers, blister towers, spray towers and venturi towers. The washing liquid supply device 10 2 is, for example, connected to the washing tower 100 to supply the washing liquid 1 16 to the washing tower 100. The washing liquid 1 1 6 includes clean water, tap water, and condensed water. The water softener 1 0 4 is installed in the washing tower 1 0 0 and the washing liquid supply device 1 0 2

9954twf.ptd Page 10 546159 V. Description of the invention (6) Between '6' to soften the washing liquid supplied by the washing liquid supply device 丨 〇 2 and send it to the washing tower 100. The water softening device 04 is, for example, a method for removing calcium ions and magnesium ions in the washing solution 120, and the method for removing calcium ions and magnesium ions includes a chemical precipitation method or an ion exchange method. The inlet end and outlet end of the washing liquid circulation pump 106 are respectively connected to the bottom and the top of the washing tower 1000 to circulate the washing liquid 丨 6 in the washing tower 100. That is. This washing liquid circulation pump 1 06 draws the washing liquid 1 16 'from the bottom of the washing tower 100, and sends the washing liquid 1 16 to the top of the washing tower 100, and then sets the washing liquid through the washing liquid 1 1 8 After spraying into the tower, it will drop into a droplet shape and flow back to the bottom of the washing tower 1000. Then, the washing liquid will be drawn from the bottom of the washing tower 100 and sent to the top of the washing tower. 6 circulates in the washing tower 100. Among them, the washing liquid spraying device 1 1 8 can evenly distribute the washing liquid 1 1 6 and spray downwards, and fully contact the exhaust gas. The dosing device 108 is, for example, connected to the washing tower 100 to control the cycle washing in the washing soil; the acid test value of the strip liquid is, for example, greater than ρ Η 1 0.5. Dosing The medicine added by Changzhi 108 can make acid and alkali neutralization reaction between the washing liquid and the exhaust gas, and effectively remove the acidic substances in the exhaust gas. The exhaust gas injection pipe 110 is connected to the washing tower 100, and an exhaust gas is introduced into the washing tower 100. The exhaust gas 114 to be treated therein is a mixed acid gas such as hydrogen fluoride, hydrogen chloride, nitric acid gas or a gas including at least one of them. The exhaust gas exhaust pipe 112 is connected to the washing tower, so that the gas treated by the washing tower 1000 is discharged into the atmosphere. In addition, in order to increase the liquid-gas exchange area, some packing materials (Packing) 120 are usually filled in the washing column 1000. The packing materials have many different lllgllii nil

IP

II 995 仏 Vi.ptd Page 11 546159 V. Description of the invention (7) The shape has its unique surface area for the designer to choose to use, such as Raschig ring and Bell saddle ring. In addition, there is an acid-base detector 22 in the washing tower. This acid is connected to the dosing device at the detector 1 22 to monitor the acid test of the washing solution. The amount of drug added to the washing tower 100 was controlled by the galler device 108. For example, ~ and when the acid-base value detected by the acid detection detector is lower than the set value, send-and to the dosing device, so that the dosing device is turned on and the medicine is added to Λ. / 疋 4 Tower The present invention uses a dosing device 108 to adjust the pH value of the washing strip 11 in the washing tower 11 00 to pH 1 0.5 or more, so that the acid gas can be fully reacted with the strong alkali within the maximum time. Reaction, so that the removal rate of acid gas in the exhaust gas is improved, and the problem of sour taste is completely solved. However, when the pH value of the washing solution 6 is increased to more than 1 ^, the calcium ions and magnesium ions contained in the washing solution 116 will form scales such as calcium hydroxide and magnesium hydroxide with hydrogen ions. Attachment to the object is caused by 冼 森 L 〇, internal contamination caused scaling, which caused the internal clogging of the washing tower 100 and caused the internal 4 I difference. Therefore, the present invention is provided between the washing liquid supply device 10 and the washing tower 100. The temple yarn clerk W 1 ^ person 1 is a filial piety water device 1 04 for removing the liquid contained in the washing liquid 1 1 6 | Bow ions and 锃 M ^, t L, nc and town ions. Make the pH value of the washing solution 1 1 6 to be adjusted to more than 10.5 · T ^ ^ ^, ^, π Λ feet, such as the waste oxygen 1 1 4 treatment efficiency, and make the strip washing tower 1 0 0 No fouling and smooth operation. The exhaust gas treatment system of the washing tower described in the previous article will be described next, and the exhaust gas treatment method of the strip washing tower disclosed in this embodiment will be described next. First, a washing liquid is provided. The use of the washing liquid 100 / washing liquid 116 flows from the top of the tower and passes through the spraying device: 二 / 鹿 下 ’The washing liquid i i 6 after coming into contact with the exhaust gas flows to the bottom of the tower, and then

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II Page 12 546159 V. Description of the invention (8) The washing liquid circulation pump 1 06 is transported to the top of the tower for recycling. Before use, the washing liquid 11 6 is subjected to a softening step of metal ions such as calcium ions and magnesium ions in the liquid, and then Adding agent 1 2 4 is liquid test, for example, adjusting the pH value of the washing liquid to be greater than 10 · 5; and then introducing the waste gas to be treated from the bottom of the tower 丨 4 such as hydrogen fluoride, hydrogen gas, and nitric acid mixed acid gas Or at least one of the gases is included in the scrubbing; in the column 1000, upward flow comes into contact with the washing liquid, and the pollutants in the exhaust gas 1 1 4 are dissolved in the washing liquid 1 1 6 and purified by the washing liquid 1 1 6 The gas is discharged from the top of the tower. The present invention adjusts the acid test value of the washing liquid 1 16 to more than 10.5. The cultural gas can fully react with the strong test within the reaction time, so that the removal rate of hydrogen gas can be prevented from 82. % ~ 95% is increased to 100%, and the removal rate of hydrogen fluoride is increased from 39% to 91% to about 99.93%, which completely solves the problem of sour taste. However, when the acid test value of the strip washing liquid is raised to more than 10 · 5, the inside of the washing tower will begin to fouling ', causing the internal pressure difference to rise and the internal blockage. The reason for this is that the supplied strip washing liquid 11 6 itself contains extremely high concentrations of word ions and ballast ions. When the acid test value is below 9 · 0, sulfate words and suspended solids of rubidium sulfate will be formed, which will not cause scaling. However, when the acid-base value is greater than 0.5, the calcium ions and magnesium ions in the washing liquid 116 will form hydroxide scales and hydroxide scales with hydroxide ions. In order to solve the problem of scaling inside the washing bar under the environment where the pH value of the washing liquid is greater than ρΗΐ0.5, it is tied to the washing liquid supply device 丨 〇2 to provide washing bar night 1 16 to the washing tower 100, add A water softening device 104 is set up to remove calcium ions and magnesium ions contained in the washing liquid 116. In order to improve the efficiency of waste gas treatment under the condition that the pH value of the washing solution 丨 6 is adjusted to more than 10.5,

9954twf.ptcl 546159 V. Description of the invention (9) The washing tower 100 can be prevented from scaling and can be operated smoothly. The present invention increases the acid-base neutralization of exhaust gas by increasing the pH value of the washing liquid to 10.5, and uses a soft water device to remove the calcium ions and magnesium ions contained in the circulating washing liquid, which can avoid washing. Fouling inside the tower can improve exhaust gas removal efficiency. Because the present invention does not need to install a local washing tower and increase the water consumption, only a set of water softening device can be used to improve the efficiency of exhaust gas treatment, so the cost of exhaust gas treatment can be saved. Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and retouching without departing from the spirit and scope of the present invention. The guarantee of the invention | The scope shall be determined by the scope of the attached patent application.

9954twf.ptd Page 14 i546159 Brief description of the drawings Figure 1 and Figure 1 show the basic structure of the scrubber exhaust gas treatment system.

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Claims (1)

546159 6. Application patent scope 1. A scrubber exhaust gas treatment system, the system includes at least: a scrubber tower; a scrubber liquid supply device, the scrubber liquid supply device is connected to the scrubber tower, and is used to supply a scrubber liquid to the In the washing column; a water softening device, which is disposed between the washing tower and the washing liquid supply device, to soften the washing liquid supplied by the washing liquid supply device and send the washing liquid to the washing tower; A washing liquid circulation pump, the washing liquid circulation pump connects the bottom and the top of the washing tower, so that the washing liquid can be circulated in the washing tower; a medicine adding device, the medicine adding device is connected to the washing tower and controls The acid check value of the strip washing solution in the elution tower is greater than ρ Η 1 0.5 or more; an exhaust gas injection pipe connected to the washing tower, so that an exhaust gas is introduced into the washing tower, And an exhaust gas exhaust pipe, which is connected to the washing tower to discharge the gas processed by the washing tower to the atmosphere. 2. The scrubbing tower exhaust gas treatment system as described in item 1 of the scope of patent application, which further includes an acid-base detector, which is arranged in the strip washing tower to monitor the acid of the washing solution Verification value. 3. The scrubber exhaust gas treatment system according to item 1 of the scope of the patent application, further comprising a scrubbing liquid spraying device, the scrubbing liquid spraying device is disposed on the top of the scrubbing tower to spray the scrubbing liquid. 4. The scrubber exhaust gas treatment system according to item 1 of the scope of the patent application, wherein the exhaust gas includes at least one of hydrogen fluoride gas, hydrogen gas gas, and nitric acid gas. 9954twf.ptd Page 16 546159 6. Scope of Patent Application 5 · The scrubber exhaust gas treatment system described in item 1 of the scope of patent application, wherein the medicament added to the scrubber by the dosing device includes sodium hydroxide. 6. The scrubbing tower exhaust gas treatment system according to item 1 of the scope of the patent application, wherein the scrubbing tower includes one of a packed tower, a blister tower, a spray tower and a vent tower. 7. The scrubber exhaust gas treatment system according to item 1 of the scope of the patent application, wherein the scrubber is filled with a Raschig ring. 8. The scrubber exhaust gas treatment system according to item 1 of the scope of the patent application, wherein the washing liquid includes clean water. 9. The scrubber exhaust gas treatment system as described in item 1 of the scope of patent application, wherein the washing liquid includes tap water. 10. The exhaust gas treatment system for a scrubbing tower as described in item 1 of the scope of the patent application, wherein the strip washing liquid includes condensed water. 1 1. A method for treating exhaust gas from a washing tower, the method comprising at least the following steps: providing a washing liquid and subjecting the washing liquid to a softening step; injecting the softened washing liquid into a washing tower; adding a medicament To the washing> strip column to adjust the washing) the acid value of the strip solution is greater than pHl 0.5; inject an exhaust gas into the washing tower; mix the exhaust gas with the washing liquid; and discharge after the washing liquid treatment Of gas. 1 2. The scrubber exhaust gas treatment party as described in item 11 of the scope of patent application 9954twf.ptd Page 17 546159% 9954twf.ptd Page 18