JPH0521118U - Smoke Eliminator for Diesel Engine - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a smoke eliminating device with a high dust removal rate, a low exhaust gas temperature, and a reduced exhaust noise. [Structure] A cyclone dust collector that removes soot and dust in exhaust gas of a diesel engine, a heater that heats the exhaust gas collected by the dust collector to an appropriate temperature, and fine particles in the exhaust gas heated by this heater A catalyst device that burns soot dust and a cooler that cools the exhaust gas in which the fine dust dust is burned by the catalyst device to a safe temperature are provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a smoke eliminator for a diesel engine for a power generator installed as an emergency power supply facility for a subway.

[0002]

[Prior Art]

 In a diesel engine, the heterogeneous mixture is burned with excess air and therefore contains smoke in the exhaust gas. Smoke is roughly classified into white smoke and black smoke (including gray).

White smoke is a fuel or lubricating oil that has not been burned or is cooled and atomized, and is often seen when idling or at light load, but it disappears as the load increases.

[0004] Black smoke is carbonized particles (soot dust) generated by a local air-fuel mixture in the combustion chamber, and re-combusts when exposed to a high temperature, but remains as it is if the temperature is low or the residence time in the combustion chamber is short. It is discharged and its concentration increases as the load increases.

Therefore, since the smoke can be extinguished by removing the dust in the exhaust gas, conventionally, a cyclone dust collector, an electric dust collector, or a wet dust collector in which a scrubber and a filter are combined is used as a smoke eliminating device. It had been.

[0006]

[Problems to be solved by the device]

The cyclone dust collector used to remove dust for smoke elimination has a low dust removal rate and cannot remove fine dust of about 10 μm or less. An electric dust collector can collect fine dust particles up to about 10 ^-2 μm, but the equipment is large and expensive. Wet dust collectors are relatively inexpensive, but the filters have to be replaced frequently, and white smoke is visible due to the inclusion of steam in the exhaust gas, which is not desirable.

Exhaust gas from a diesel engine installed underground such as in a subway facility is discharged from the side of the road, the side of the sidewalk near the roadway, etc. In addition to being required, it is also required to suppress the temperature and noise of exhaust gas.

The present invention has been made in view of the above points, and an object of the present invention is to provide a smoke eliminating device having a high dust removal rate, a low exhaust gas temperature, and a low exhaust noise. I am trying.

[0009]

[Means for Solving the Problems]

 Means for solving the above problems in the present invention are a cyclone dust collector that removes dust in exhaust gas of a diesel engine, and a heater that heats the exhaust gas collected by the dust collector to an appropriate temperature, Smoke-free diesel engine equipped with a catalyst device that burns fine soot and dust in exhaust gas heated by this heater, and a cooler that cools the exhaust gas burned by the catalyst device to a safe temperature Make a device.

[0010]

[Action]

 When the generator is operated due to a power outage of the commercial power supply, start the diesel engine, load it in the shortest time, and supply power to the heater. Exhaust gas containing diesel engine smoke removes large particles of soot in a cyclone dust collector. In the heater, the temperature controller heats the exhaust gas at the inlet of the catalyst device so that the catalyst has a good reaction temperature. Since the good reaction temperature of the catalyst is about 400 to 500 ° C, the temperature is set to about 470 ° C by allowing a margin by the temperature controller. Also, the exhaust gas temperature of a diesel engine is about 150 ° C under no-load operation and about 500 ° C under full-load operation, and the exhaust gas temperature when operating under a load close to full load is high. Is not heated. The exhaust gas whose temperature has been adjusted by the heater enters the catalyst device and burns the fine particulate dust that could not be removed by the cyclone dust collector by the catalyst. This combustion gas is cooled down to a safe temperature and released to the atmosphere.

When the power generator is operated in the presence of a commercial power source, the catalyst device and the main passage of the exhaust gas are preheated prior to starting the diesel engine to remove the fine particulate dust attached to the catalyst. Incinerate unburned material.

[0012]

【Example】

 The present invention will be described below based on an embodiment shown in FIG. FIG. 1 is a block diagram showing an embodiment of the present invention. 1 is a diesel engine for a power generator, 2 is a cyclone dust collector, 3 is a heater using an electric heater, 4 is a rectifier, 5 is platinum, A catalyst device using palladium and a mixture thereof as a catalyst, 6 is a cooler composed of a gas-water heat exchanger, and 7 is an exhaust duct connected to an exhaust port provided on the side of a road or the like. A thick line 8 indicates the main passage of exhaust gas.

Reference numeral 9 is a temperature controller, 10 is a pressure switch, 11 is a bypass valve provided in the side passage 12 of the catalyst device 5, 13 is an electromagnetic valve provided in the water supply pipe 14 of the cooler 6, and 15 is an electric motor. It is an air circulation path that connects the outlet of the catalyst device 5 and the inlet of the cyclone dust collector 2 via a valve 16 and a blower 17. Reference numeral 18 is a rotary airlock valve provided at the dust discharge portion of the cyclone dust collector 2, and 19 is a dust bunker. Further, 20 surrounded by a chain double-dashed line shows a smoke eliminating device portion according to the present invention.

When the power generator is operated due to a power failure of the commercial power source, the diesel engine 1 is started to perform load operation in the shortest time, and power is also supplied to the heater 3. The exhaust gas containing the smoke of the diesel engine 1 is subjected to removal of soot and dust with large particles in the cyclone dust collector 2. In the heater 3, the temperature controller 9 heats the exhaust gas at the inlet of the catalyst device 5 so that the temperature of the exhaust gas becomes a good reaction temperature of the catalyst.

When the favorable reaction temperature of the catalyst is 400 to 500 ° C., the set temperature of the temperature controller 9 is set to about 470 ° C. in consideration of a margin. Moreover, the exhaust gas temperature of the diesel engine 1 is about 150 ° C. under no-load operation and about 500 ° C. under full-load operation. Of course, the exhaust-gas temperature when operating under a load close to full load is Since it is high, heating by the heater 3 is not performed. The exhaust gas whose temperature has been adjusted by the heater 3 is rectified by the rectifying device 4, enters the catalyst device 5, and the particulate soot that cannot be removed by the cyclone dust collector 2 is burned by the catalyst. If the exhaust gas pressure at the inlet of the catalyst device 5 rises abnormally due to clogging of the catalyst part, etc., an alarm is issued by the pressure switch 10 to display and the bypass valve 11 is opened, and exhaust gas is passed through the side passage 12 to continue the operation. To do. The exhaust gas from which the fine particulate dust is burned and the smoke is extinguished is cooled by the cooler 6 so that the exhaust temperature at the exhaust port becomes a safe temperature, and is discharged into the atmosphere through the exhaust duct 7.

After the operation is completed, when the diesel engine 1 is stopped, the rotary air lock valve 18 of the cyclone dust collector 2 is opened, and the collected dust is discharged to the dust bunker 14 to prepare for the next operation.

The smoke eliminator 20 surrounded by a chain double-dashed line forms a large noise eliminator that causes exhaust gas of the diesel engine 1 to repeat expansion, contraction, refraction, shunting, and merging. Combined with the fact that the outside of the heat insulating material for the devices, equipment, and pipes in 20 was covered with a perforated plate and fixed, a large sound deadening effect was achieved.

When the power generator is operated with a commercial power source, the catalyst device 5 and the exhaust gas main passage 8 are preheated before the diesel engine 1 is started. That is, the valve 16 is opened and the blower 17 is operated to circulate air through the exhaust gas main passage 8 from the inlet of the cyclone dust collector 2 to the catalyst device 5 and the air circulation passage 15, and the heater 3 controls the temperature. The diesel engine 1 is started after heating to about the set temperature of the controller. In case of no-load operation by preheating, of course, even if it takes a while for the synchronous parallel input to the commercial power source and the rise in the exhaust gas temperature is delayed, smoke is not emitted from the exhaust port on the side of the road. It's done.

When the no-load operation is continued for the purpose of adjustment after maintenance and inspection of the power generator, the exhaust gas temperature of the diesel engine 1 does not rise, and even if it is heated by the heater 3, the inlet of the catalyst device 5 The exhaust gas temperature at gradually decreases below the good reaction temperature of the catalyst. The same is true when the light load operation in which the exhaust gas temperature is low is continued. By increasing the capacity of the heater 3, it is possible to prevent the exhaust gas temperature from decreasing at the inlet of the catalyst device 5, but it becomes an uneconomical device, and the required no-load operation duration may be longer or shorter. The capacity of the heater 3 is appropriately selected.

Therefore, when the diesel engine 1 is stopped after no-load or light-load operation, the catalyst device 5 is heated together with the main passage 8 for the exhaust gas in the same manner as the above-described preheating, and the unburned fine particulate dust adhering to the catalyst is not burned. Incinerate the minutes.

[0021]

[Effect of the device]

 The diesel engine smoke eliminator according to the present invention is a combination of a cyclone dust collector that removes coarse particulate dust and a catalyst device that burns and removes fine particulate dust, and is used as a temperature controller even if the exhaust gas temperature of the diesel engine changes. A heater is used to control the catalyst to a good reaction temperature to obtain a high dust removal rate. In the case of a diesel engine that uses A heavy oil and kerosene as a fuel, the removal rate of about 92% is obtained by the JISZ8808 circular filter paper weight method. ing.

When there is a commercial power source, by performing preheating, it is possible to improve the dust removal rate at the time of no-load operation or light-load operation subsequent to start-up and eliminate smoke.

In addition, compared to a large and expensive electric dust collector, it is small and inexpensive, and there are no replacement parts such as filters unlike a wet dust collector, and inspection and maintenance are sufficient once a year. Even if the catalytic converter becomes clogged, operation can be continued by detecting it with the pressure switch and opening the bypass valve.

Exhaust gas discharged through the exhaust duct to the atmosphere from the exhaust port provided on the side of the road is cooled to a safe temperature by the cooler and then discharged, and the smoke eliminator itself has a noise reduction effect. It functions as a large muffler, and has various practical effects such that exhaust gas noise at the exhaust port does not become a problem.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

[Explanation of symbols]

1 ... Diesel engine, 2 ... Cyclone dust collector, 3 ...
Heater, 5 ... Catalyst device, 6 ... Cooler.

Claims (1)

[Scope of utility model registration request] 1. A cyclone dust collector for removing soot and dust in the exhaust gas of a diesel engine, a heater for heating the exhaust gas collected by the dust collector to an appropriate temperature, and an exhaust gas heated by this heater 2. A smoke eliminating device for a diesel engine, comprising: a catalyst device for burning fine soot and dust, and a cooler for cooling exhaust gas burned by the catalyst device to a safe temperature.