Exhaust purification device burner

Abstract

This burner is disposed at the upstream side of a DPF and raises the temperature of exhaust by combusting an air-fuel mixture of air and fuel in a combustion region within a flame holder. The burner is provided with: an upstream-side cover enclosing the peripheral wall of the flame holder; and a partition wall that partitions the gap between the flame holder and the upstream-side cover into a prior-stage exhaust chamber and a latter-state exhaust chamber. An exhaust tube through which exhaust from an engine flows is connected to the upstream-side cover; a through hole that interconnects the prior-stage exhaust chamber and the latter-stage exhaust chamber is formed at the partition wall; exhaust flows in from the exhaust tube at the prior-stage exhaust chamber; and exhaust flows in from the prior-stage exhaust chamber through the through hole to the latter-stage exhaust chamber.

1 . A burner for an exhaust purification device, comprising:
 a tubular flame stabilizer having a space including a combustion area, in which air-fuel mixture of fuel and air is combusted, an ejection port for ejecting combustion gas, a small diameter portion, and a large diameter portion having an inner diameter larger than the small diameter portion;   a tubular cover that surrounds the flame stabilizer, wherein a gap is formed between an inner circumference face of the cover and an outer circumference face of the flame stabilizer;   an exhaust pipe connected to the cover to deliver exhaust gas into the gap; and   a partition portion arranged in the gap to partition the gap into an upstream exhaust chamber and a downstream exhaust chamber, wherein the partition portion is arranged between an outer circumference face of the large diameter portion and the inner circumference face of the cover in the gap, wherein   the upstream exhaust chamber is connected to the exhaust pipe and the downstream exhaust chamber, and   the downstream exhaust chamber is connected to the ejection port of the flame stabilizer.   
     
     
         2 . The burner for an exhaust purification device according to  claim 1 , wherein
 the flame stabilizer is shaped as a cylindrical tube, and   the exhaust pipe extends in the tangential direction of the outer circumferential face of the flame stabilizer.   
     
     
         3 . The burner for an exhaust purification device according to  claim 2 , wherein the exhaust pipe connects to an outer circumferential face of the cover at one location. 
     
     
         4 . The burner for an exhaust purification device according to  claim 1 , wherein
 the partition portion is configured to:   protrude from the outer circumferential face of the flame stabilizer toward the inner circumferential face of the cover;   be coupled to the outer circumferential face of the flame stabilizer and the inner circumferential face of the cover; and   be a partition wall that partitions the gap into the upstream exhaust chamber and the downstream exhaust chamber, and   the partition wall includes a communication hole that extends through the partition wall such that the upstream exhaust chamber communicates with the downstream exhaust chamber.   
     
     
         5 . The burner for an exhaust purification device according to  claim 1 , wherein a flow path cross-sectional area of the exhaust pipe is larger than a flow path cross-sectional area of the upstream exhaust chamber. 
     
     
         6 . The burner for an exhaust purification device according to  claim 1 , further comprising an ignition portion, which is arranged in the space in the flame stabilizer to ignite the air-fuel mixture,
 wherein with respect to distances in the axial direction of the flame stabilizer, a distance between the partition portion and the ejection port is shorter than a distance between the ignition portion and the ejection port.   
     
     
         7 . The burner for an exhaust purification device according to  claim 1 , further comprising:
 a premixing portion, which is arranged in the space in the flame stabilizer and produces the air-fuel mixture; and   an ignition portion, which is arranged in the space in the flame stabilizer and ignites the air-fuel mixture produced in the premixing portion,   wherein a distance between the ignition portion and the upstream exhaust chamber is shorter than a distance between the ignition portion and the downstream exhaust chamber.