Exhaust treatment device of diesel engine

Patent metadata

Field	Value
Publication number	US-9353666-B2
Application number	US-201314016366-A
Country	US
Kind code	B2
Filing date	Sep 3, 2013
Priority date	Sep 11, 2012
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

An exhaust treatment device of a diesel engine is provided in which combustible gas is burned with oxygen in exhaust, combustion heat increases a temperature of the exhaust, and heat of the exhaust can burn and remove PM accumulating in a DPF. In order to cause a heater for radiating heat at a start of generation of the combustible gas to enter a catalyst inlet portion, and fit a liquid fuel retaining member over a periphery of the heater, a guide plate is provided to a lower face of the liquid fuel retaining member so that the air-fuel mixture moving down in the liquid fuel retaining member flows along an upper face of the guide plate out to a periphery of the guide plate.

First claim

What is claim is:

1. An exhaust treatment device of a diesel engine comprising:
a combustible gas generator,
a combustible gas generating catalyst chamber provided in the combustible gas generator,
a combustible gas generating catalyst for generating combustible gas, housed in the combustible gas generating catalyst chamber and having a catalyst inlet portion at a central upper portion thereof and a catalyst outlet portion in a lower end portion thereof,
a heater in the catalyst inlet portion of the combustible gas generating catalyst,
a liquid fuel retaining member fitted over a periphery of the heater, and
a guide plate positioned at a lower face of the liquid fuel retaining member,

an air-fuel mixing chamber formed at an upper portion of the combustible gas generator, air and liquid fuel being supplied into the air-fuel mixing chamber to form an air-fuel mixture,
a combustible gas release port,
an exhaust passage, and
a diesel particulate filter (DPF),
wherein:
the air-fuel mixture is supplied from a lower end portion of the air-fuel mixing chamber to the combustible gas generating catalyst through the catalyst inlet portion, and flows down the liquid fuel retaining member and along an upper face of the guide plate to a periphery of the guide plate,
the heater radiates heat to generate combustible gas from the air-fuel mixture by the combustible gas generating catalyst, the generated combustible gas flows out of the combustible gas generating catalyst through the catalyst outlet portion, and is released from the combustible gas release port into the exhaust passage on an upstream side of the DPF, and
the combustible gas is burned with oxygen in exhaust located in the exhaust passage, which creates combustion heat thereby increasing a temperature of the exhaust, and heat of the exhaust burning and removing particulate matter (PM) accumulating in the DPF.

2. The exhaust treatment device of the diesel engine according to claim 1 , further comprising:
an air supply device,
a catalyst temperature detecting device having a temperature detecting portion positioned within the combustible gas generating catalyst below the guide plate, and
a control device in operative communication with the catalyst temperature detecting device, the air supply device and the liquid fuel supply device, and configured to direct the air supply device and the liquid fuel supply device to adjust respective amounts of the air and the liquid fuel to be supplied into the air-fuel mixing chamber according to a temperature of the combustible gas generating catalyst detected by the catalyst temperature detecting device and thereby adjust the temperature of the combustible gas generating catalyst.

3. The exhaust treatment device of the diesel engine according to claim 2 , further comprising a heat insulating material interposed between an inner peripheral face of the combustible gas generating catalyst chamber and an outer peripheral face of the combustible gas generating catalyst without being interposed between upper end edge portions of the inner peripheral face of the combustible gas generating catalyst chamber and the outer peripheral face of the combustible gas generating catalyst, the upper end edge portions of the inner peripheral face of the combustible gas generating catalyst chamber being brought in close contact with each other such that catalytic reaction heat is radiated from the upper end edge portion of the outer peripheral face of the combustible gas generating catalyst to the upper end edge portion of the inner peripheral face of the combustible gas generating catalyst chamber.

4. The exhaust treatment device of the diesel engine according to claim 2 , wherein the combustible gas generating catalyst comprises catalyst supports supporting a catalyst component, the catalyst supports being formed by two parts divided along respective vertical division faces along a central axis of the combustible gas generating catalyst, the liquid fuel retaining member and the guide plate being sandwiched and fixed between the two parts forming the catalyst supports.

5. The exhaust treatment device of the diesel engine according to claim 4 , further comprising a heat insulating material interposed between an inner peripheral face of the combustible gas generating catalyst chamber and an outer peripheral face of the combustible gas generating catalyst without being interposed between upper end edge portions of the inner peripheral face of the combustible gas generating catalyst chamber and the outer peripheral face of the combustible gas generating catalyst, the upper end edge portions of the inner peripheral face of the combustible gas generating catalyst chamber being brought in close contact with each other such that catalytic reaction heat is radiated from the upper end edge portion of the outer peripheral face of the combustible gas generating catalyst to the upper end edge portion of the inner peripheral face of the combustible gas generating catalyst chamber.

6. The exhaust treatment device of the diesel engine according to claim 4 , wherein the combustible gas generating catalyst further comprises an insertion hole through which the temperature detecting portion of the catalyst temperature detecting device is inserted therein, a central axis of the insertion hole extending orthogonally to the central axis of the combustible gas generating catalyst, along a direction parallel to the division faces, such that the catalyst supports are of the same shape.

7. The exhaust treatment device of the diesel engine according to claim 6 , further comprising a heat insulating material interposed between an inner peripheral face of the combustible gas generating catalyst chamber and an outer peripheral face of the combustible gas generating catalyst without being interposed between upper end edge portions of the inner peripheral face of the combustible gas generating catalyst chamber and the outer peripheral face of the combustible gas generating catalyst, the upper end edge portions of the inner peripheral face of the combustible gas generating catalyst chamber being brought in close contact with each other such that catalytic reaction heat is radiated from the upper end edge portion of the outer peripheral face of the combustible gas generating catalyst to the upper end edge portion of the inner peripheral face of the combustible gas generating catalyst chamber.

8. The exhaust treatment device of the diesel engine according to claim 1 , further comprising a heat insulating material interposed between an inner peripheral face of the combustible gas generating catalyst chamber and an outer peripheral face of the combustible gas generating catalyst without being interposed between upper end edge portions of the inner peripheral face of the combustible gas generating catalyst chamber and the outer peripheral face of the combustible gas generating catalyst, the upper end edge portions of the inner peripheral face of the combustible gas generating catalyst chamber being brought in close contact with each other such that catalytic reaction heat is radiated from the upper end edge portion of the outer peripheral face of the combustible gas generating catalyst to the upper end edge portion of the inner peripheral face of the combustible gas generating catalyst chamber.

Assignees

• Kubota Kk

Inventors

• Onishi Takashi
• Morinaga Hidetaka
• Takemoto Yoshikazu
• Nakahira Toshio
• Okuda Mitsugu
• Naito Keita

Classifications

• F01N2560/06

  the means being a temperature sensor · CPC title

• F01N3/025

  using fuel burner or by adding fuel to exhaust · CPC title

• F01N2240/14

  a fuel burner · CPC title

• F01N3/30

  Arrangements for supply of additional air (control, e.g. using by-passes or variable air pump drives, F01N3/22) · CPC title

• F01N3/2889 Primary

  with heat exchangers in a single housing · CPC title