JP3424004B2 - Wet exhaust gas purifier with reduced liquid loss - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a wet type exhaust gas purifying apparatus in which a purifying liquid for purifying exhaust gas is less likely to flow outside. 2. Description of the Related Art A conventional wet exhaust gas purifying apparatus, also called a scrubber, is generally very large, and therefore cannot be mounted on an ordinary land transportation engine or the like. [0003] In the conventional wet exhaust gas purifying device, droplets are inevitably generated, and these droplets are continuously generated in large amounts, and are discharged together with the exhaust gas to the outside of the device. The phenomenon of so-called entrainment of scattering occurs. In order to prevent the entrainment, the device becomes complicated and large, and there is a problem that it cannot be mounted on general land transportation. According to the present invention, even when the engine is operated at a high speed, the amount of liquid flowing out is extremely limited, and the size of the apparatus is reduced so that the wet exhaust can be mounted on general land transportation. It is intended to provide a gas purification device. [0005] In order to achieve the above object, in the wet exhaust gas purifying apparatus of the present invention, the reaction tank for containing the purifying solution is made as small as possible. The tank is filled with an appropriate amount of a fibrous substance which has a large liquid holding capacity and is nonflammable, and a plurality of baffles are attached at various places in the apparatus in order to remove splashes. [0006] The non-combustible material on fiber is preferably glass fiber or stainless steel wool, and its filling amount is desirably 10% or more of the apparent capacity of the reaction tank. [0007] The capacity of the reaction tank for storing the purifying liquid is proportional to the displacement of the engine, but is desirably smaller than the displacement of the engine. [0008] Since the exhaust gas of a diesel engine has a high pressure, a part of the purifying liquid flows out to the outside when the engine is rotated at a high speed. However, since the volume of the outflow is small due to the small capacity of the reaction tank, the volume of the outflow does not exceed the volume, and the time of the outflow is limited to a very short time. Also, at this time, the liquid in the reaction tank is prevented from being depleted in a short time due to the water retaining action of the fibrous substance filled in the reaction tank. [0010] The fibrous substance used as the filler has not only a large water retention capacity of liquid but also a very large surface area per unit volume, so that the gas-liquid contact efficiency between the exhaust gas and the purifying solution is increased, and therefore the chemical reaction Is extremely efficient and also enhances the trapping effect of suspended particulate matter such as black smoke. [0011] A plurality of baffles are attached to the inner wall of the reaction tank containing the purifying solution and the gas passage in the apparatus in order to return the generated droplets to the original reaction tank as much as possible. The exhaust gas of a diesel engine is hot and a certain small amount of the purifying liquid evaporates to dryness in a very short time unless the liquid is replenished from the outside. Therefore, in order to prevent this, during the operation, a replenisher equivalent to the amount of evaporation is always added and replenished. Therefore, unless the amount of replenisher exceeds the amount lost by evaporation, the purifying solution will not be continuously discharged to the outside. Conversely, if the amount of replenisher is less than the amount lost by evaporation, the efficiency of the chemical reaction decreases, but
As long as replenishment is being performed, the filling in the reaction tank is kept wet and can perform a purifying action. Embodiments of the present invention will be described with reference to the drawings based on embodiments. In FIG. 1, the inside of a reaction tank 1 containing an aqueous solution for purification is filled with glass fibers 3 having water retention. A pipe outlet 5 for introducing exhaust gas from the outside is provided at a position near the bottom of the reaction tank 1. The exhaust gas outlet 5 is located inside the liquid. A plurality of baffles 4 are provided on the inner wall of the reaction tank 1 and the exhaust gas passage, and are arranged so that the droplets generated by the ejection of the exhaust gas return to the original liquid level. A thin pipe 7 for the replenisher is connected near the lower part of the reaction tank. The replenisher is replenished from a separate replenisher tank 10 by the action of a small refill pump 11, an ejector, or the like. In order to balance the amount of replenisher with the amount evaporated by high-temperature exhaust gas, a pinch cock 12 is provided in the replenisher circuit to adjust the amount of the replenisher appropriately. An auxiliary tank 2 is provided adjacent to the tank. The auxiliary tank 2 serves to reduce the amount of splashes directly ejected from the reaction tank to the outside, and serves as a dam. The auxiliary tank 2 has an overflow outlet 1
4 is provided. This position is located below the outlet 6 of the purified exhaust gas, and is located in the middle of the auxiliary tank 2. The role of this overflow is that the replenishment balance of the liquid is lost, and the replenisher amount becomes larger than the evaporation loss amount.
This prevents the auxiliary tank 2 from being filled with liquid. A waste liquid valve 8 is provided at the bottom of the reaction tank 1 for storing the purifying liquid, and is used to discharge polluted waste liquid to the outside of the apparatus as required. In order to keep the liquid level in the reaction tank 1 constant, a sensor 13 for automatically operating and stopping the replenisher is attached to the wall surface of the reaction tank 1 or a liquid level gauge. The present invention is configured as described above, and has the following effects. Since the volume of the reaction tank containing the purifying aqueous solution is extremely small, even if there is a temporary ejection of the solution, the amount is very limited and small, and the time during which the solution is ejected is extremely short. It's short. Since the entire purification device is small, it can be mounted on many land transportations that were not possible before.
The storage position can be at the bottom of the bottom of the vehicle body. Therefore, there are no restrictions on the number of passengers and the amount of cargo on board. Since the glass fiber in the reaction tank has a large water retention capacity and is nonflammable, even if the engine is rotated at a high output, the entire amount of the liquid in the reaction tank is not spouted at once, and is temporarily refilled. Even if the route is broken and the liquid is depleted, the purifying device is not disabled and there is no danger of fire. Glass fiber used as a filler in a reaction tank has high chemical resistance and does not deteriorate even when used by being immersed in various chemical aqueous solutions for a long period of time, and is inexpensive. The exhaust gas of a diesel engine has a very high temperature of 300 ° C. or higher, and the aqueous solution is constantly evaporated and lost by the high-temperature exhaust gas. However, this can offset a large amount of harmful thermal energy by the heat of vaporization, which can help improve the environment. The temperature of the purified gas discharged from the purification device in this way is usually within 50 ° C. This effect works when the engine is used in a closed area. The solvent of the solution used for purification is water,
It is a very universal substance. Therefore, it can be obtained anywhere in the country, and it is not necessary to use tap water for drinking.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical cross-sectional view of a wet exhaust gas purifying apparatus in which the flow of a liquid is reduced. FIG. 2 is a schematic view of a replenisher tank and a replenisher for a wet exhaust gas purifying apparatus with reduced liquid loss. [Description of Signs] 1 Small reaction tank 2 Auxiliary tank 3 Filling material 4 Baffle plate 5 Exhaust gas intake port 6 Purified exhaust gas outlet 7 Replenisher inlet 8 Waste liquid outlet 9 Sink plate for backflow of ejected liquid 10 Replenisher tank 11 Refill pump 12 Pinch cock 13 for adjusting the amount of replenisher Liquid level sensor 14 Overflow liquid outlet 15 Purification liquid inlet

Claims (1)

(57) [Claims 1] An exhaust gas purifying device mountable on land transportation, wherein a reaction tank containing a purifying aqueous solution is filled with water-retaining glass fiber. The outlet of a pipe for introducing exhaust gas is provided, a thin pipe for replenisher is connected near the lower part of the reaction tank, and multiple baffles are provided on the inner wall of the reaction tank and the exhaust gas passage to eject exhaust gas. Exhaust gas purifying apparatus, wherein an auxiliary tank provided with a purified exhaust gas outlet is provided adjacent to the reaction tank so as to return droplets generated by the exhaust gas to its original state.