JPH03213615A - Exhaust gas purifying system for engine - Google Patents

Abstract

PURPOSE:To take in granular or like hazardous materials in exhaust gas of an engine into condensed drops of water vapor to improve the emission control effect of the engine by flowing the exhaust gas in an expanding turbine of a turbocharger after humidifying with water vapor. CONSTITUTION:Water vapor from a humidifying unit 8 is added to exhaust gas 7 ejected from an exhausting aperture 5 of an engine 6. Then the exhaust gas is flowed into an expanding 9 of a supercharger to be adiabatically expanded to condense the water vapor, and hazardous materials in the exhaust gas are taken in water drops as condensation nucleuses. The water drops in the exhaust gas are separated from the gas with a drop separator 10, and the exhaust gas is ejected in the atmosphere through a muffler 11. On the other hand, separated water drops, condensed water 13, are stored in a tank 4 and then sent to the humidifying unit 8 through a pump 16 and a filter 15 to reuse as humidifying water. Thereby granular and gaseous hazardous materials in the exhaust gas can be removed simultaneously.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an exhaust gas purification device for an engine.

[Conventional technology]

In general, exhaust gas from gasoline engines, diesel engines, etc. contains carbon monoxide (CO) and sulfur oxides (
SOl), nitrogen oxides (NOx), particulate matter (soot,
diesel particles, etc.). - carbon oxide,
Conventional measures have been taken to reduce nitrogen oxides, such as by using catalyst devices.

[Problem to be solved by the invention]

However, no measures have been taken to address other emissions, especially particulate matter.

The purpose of the present invention is to solve the problems of the conventional device, remove harmful substances that cause air pollution such as particulate matter, carbon monoxide, sulfur oxides, and nitrogen oxides in exhaust gas, and create a clean system. An object of the present invention is to provide an exhaust gas purification system for an engine that can obtain exhaust gas.

[Means to solve the problem]

An exhaust gas purification system for an engine according to the present invention includes a turbocharger for recovering kinetic energy of exhaust gas arranged in an exhaust pipe of an engine, a humidifier 8 inserted upstream of the turbocharger 9, and a humidifier 8 that is inserted upstream of the turbocharger 9. a droplet separator 10 provided downstream of the droplet separator, a condensed water tank 14 for storing the condensed solution in the droplet separator, a device 15 for removing harmful substances from the solution in the condensed water tank, and a droplet separator 10 provided downstream of the droplet separator. It is characterized by having a droplet separator, a condensed water tank, a wood pipe connecting a harmful substance removal device and a humidification device.

[Effect]

The exhaust gas from the engine is humidified with water vapor and flows into the expansion turbine of the turbocharger. During expansion within the turbine, condensation of water vapor occurs and harmful substances such as particulate matter, nitrogen oxides, carbon oxides, sulfur oxides, etc. are entrained into the droplets. Since the droplets grow to a size of about several μm, the exhaust gas can be purified by separating them from the exhaust gas using a dust collector.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, water vapor from a humidifier 8 is added to exhaust gas 7 containing harmful substances from an exhaust port 5 of an engine 6.
When it approaches saturation, it flows into the expansion turbine 9 of the supercharger. In the expansion turbine, the exhaust gas undergoes rapid adiabatic expansion, resulting in water vapor condensation. At this time, harmful substances such as particulate matter, nitrogen oxides, carbon oxides, and sulfur oxides in the exhaust gas act as condensation nuclei and are incorporated into the generated droplets. The exhaust gas from the expansion turbine exit flows out in a gas-liquid two-phase state containing droplets, and when it passes through the droplet separator 10 (consisting of a centrifugal separator and an electrostatic precipitator), it is separated from the exhaust gas as droplets. separated. The exhaust gas from which the droplets have been removed passes through the muffler 11 and is released into the atmosphere as purified exhaust gas. On the other hand, droplets removed from the exhaust gas by the droplet separator 10, that is, condensed water 13, are stored in a condensed water tank I4. The water in the condensed water tank is sent to the humidifier 8 through the circulation pump 16 and the harmful substance removal device (high-performance water filtration filter) 15, and is reused as water for humidification.

Note that 17 is a fuel supply device.

FIG. 2 shows a schematic diagram of the state change of added water vapor in the exhaust gas in the supercharger expansion turbine. In Figure 2, A
B shows the state of the exhaust gas near saturation with water vapor added, B shows the state at the start of condensation within the expansion turbine 9, and C shows the state at the outlet of the expansion turbine.

In the expansion turbine 9, water vapor rapidly expands along AB and becomes supersaturated. When the degree of supersaturation reaches state B,
Droplet condensation of water vapor occurs rapidly, and droplets are generated within 80 minutes. The exhaust gas containing droplets enters the droplet separator 10 in state C.

The kinetic energy of the exhaust gas 7 discharged from the engine 6 is recovered by the compressor 2 connected to the expansion turbine 9, as in the case of conventional supercharged engines, and the outside air 1 is pressurized and sent to the air supply port 4. is supplied to the engine cylinders.

〔Effect of the invention〕

Since the present invention is configured as described above, it is possible to remove particulate matter from exhaust gas emitted from an engine (gasoline engine, diesel engine), and also remove nitrogen oxides (NO,) and sulfur oxides (SOx). ), - Gaseous substances such as carbon oxide (CO) can also be removed at the same time, thereby purifying the exhaust gas and preventing air pollution caused by harmful substances discharged from the engine.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an engine exhaust gas purification system according to the present invention, and FIG. 2 is a schematic diagram of state changes in the supercharger expansion turbine of water vapor added to exhaust gas. 2... Compressor, 5... Exhaust port, 6... Engine, 7... Exhaust gas, 8... Humidifier, 9...
Turbine, 10... Droplet separator, 11... Silencer,
14... Condensed water tank, 15... Harmful substance removal device, 16... Circulation pump.

Claims (1)

[Claims] A turbocharger for recovering kinetic energy of exhaust gas disposed in an exhaust pipe of an engine, a humidifier (8) inserted upstream of the turbocharger (9), and a humidifying device (8) disposed downstream of the turbocharger. a droplet separator (10), a condensate tank (14) for storing the solution condensed in the droplet separator, a device (15) for removing harmful substances in the solution of the condensate tank, and said droplet separator. An exhaust gas purification system for an engine comprising a separator, a condensed water tank, a water pipe connecting a harmful substance removal device and a humidification device.