Patent
Low NOX swirl coal combustion burner
| العنوان: | Low NOX swirl coal combustion burner |
|---|---|
| Patent Number: | 8,479,668 |
| تاريخ النشر: | July 09, 2013 |
| Appl. No: | 12/227473 |
| Application Filed: | July 18, 2007 |
| مستخلص: | A burner includes a primary air-coal mixture duct coaxially extended through a secondary air wind box, a pulverized coal separator supported within the primary air-coal mixture duct, a secondary air duct including an inner secondary air duct and an outer secondary air duct coaxially formed around the primary air-coal mixture duct, a primary air-coal mixture conical outlet coupled with the outlet of the primary air-coal mixture duct, and inner secondary air and outer conical outlets coupled with the outlets of the inner secondary air and outer secondary air ducts respectively. The conical outlets are arranged to delay the mixing time of the primary air-coal mixture and secondary air flows through the primary air-coal mixture and secondary air ducts and to prolong the residence time in the center recirculation zone under the reduction ability so as to effectively reduce the formation of NOx. |
| Inventors: | Li, Zhengqi (Nangang District Harbin, CN); Chen, Zhichao (Nangang District Harbin, CN); Sun, Rui (Nangang District Harbin, CN); Sun, Shaozeng (Nangang District Harbin, CN); Wu, Shaohua (Nangang District Harbin, CN); Qin, Ming (Nangang District Harbin, CN); Liu, Hui (Nangang District Harbin, CN); Qin, Yunkun (Nangang District Harbin, CN) |
| Assignees: | Harbin Institute of Technology (Harbin, CN) |
| Claim: | 1. A low NOx swirl coal combustion burner, comprising: an air-coal mixture duct for guiding a flow of air-coal mixture therethrough in a non-swirling manner; two or more pulverized coal separators supported within said air-coal mixture duct for partitioning said flow of air-coal mixture into a high-dense pulverized coal region at an inner central portion of said flow of air-coal mixture and a low-dense pulverized coal region at an outer peripheral portion of said flow of air-coal mixture, wherein the diameters of said pulverized coal separators are gradually and sequentially reducing towards an outlet of said air-coal mixture duct for partitioning said flow of air-coal mixture into said high-dense pulverized coal region and said low-dense pulverized coal region; inner and outer tubular sleeves encirclingly coupled with said air-coal mixture duct to form an inner secondary air duct and an outer secondary air duct, wherein a secondary air flow is partitioned into said inner secondary air duct being guided to pass through in said inner secondary air duct in a swirling manner and said outer secondary air duct being guided to straight-forwardly pass through said outer secondary air duct in a non-swirling manner, wherein said inner secondary air duct and said outer secondary air duct are coaxially formed with respect to said air-coal mixture duct such that said inner secondary air duct, said outer secondary air duct, and said air-coal mixture duct share a common axis, wherein said inner and outer secondary air ducts are arranged for partitioning said secondary air flow into an inner secondary air flow at said inner secondary air duct as an igniter for igniting said flow of air-coal mixture and an outer secondary air flow at said outer secondary air duct as an oxygen suppler for supplying enough oxygen for complete combustion of said flow of air-coal mixture, wherein said pulverized coal separators are coaxially supported within said air-coal mixture duct along a centerline thereof; an inner secondary air damper supported at an inlet of said inner secondary air duct, wherein an opening valve of said inner secondary air damper is selectively adjusted to adjustably control an amount of said secondary air flow being partitioned into said inner secondary air duct and said outer secondary air duct, such that said high-dense pulverized coal region and said low-dense pulverized coal region of said flow of air-coal mixture mix with said inner and outer secondary air flows to form a moderate central recirculation zone for reducing an emission of NOx during combustion; an air-coal mixture conical outlet, an inner secondary air conical outlet, and an outer secondary air conical outlet, wherein an opening of said air-coal mixture conical outlet, with a smaller diameter, is coupled with said outlet of said air-coal mixture duct, wherein an opening of said inner secondary air conical outlet, with a smaller diameter, is coupled with an outlet of said inner secondary air duct, wherein an opening of said outer secondary air conical outlet, with a smaller diameter, is coupled with an outlet of said outer secondary air duct, wherein said conical outlets are arranged for delaying a mixing time of said flow of air-coal mixture with said inner and outer secondary air flows and to further prolong a residence time in the center recirculation zone so as to effectively reduce the formation of NOx, wherein said air-coal mixture conical outlet is extended inclinedly at an angle α with respect to a centerline of said air-coal mixture duct, wherein said inner secondary air conical outlet is extended inclinedly at an angle β with respect to said centerline of said air-coal mixture duct, wherein said outer secondary air conical outlet is extended inclinedly at an angle γ with respect to said centerline K of said air-coal mixture duct, wherein said angles α, β, γ are the same, wherein each of said angles α, β, γ has a threshold between 15° to 35°; and an inner secondary air vane supported within said inner secondary air duct, wherein said inner secondary air vane is arranged for regulating said inner secondary air flow in a swirling manner before mixing with said flow of air-coal mixture mix. |
| Claim: | 2. A low NOx swirl coal combustion burner, comprising: an air-coal mixture duct for guiding a flow of air-coal mixture therethrough in a non-swirling manner; two or more pulverized coal separators supported within said air-coal mixture duct for partitioning said flow of air-coal mixture into a high-dense pulverized coal region at an inner central portion of said flow of air-coal mixture and a low-dense pulverized coal region at an outer peripheral portion of said flow of air-coal mixture, wherein said pulverized coal separators are coaxially supported within said air-coal mixture duct along a centerline thereof, wherein the diameters of said pulverized coal separators are gradually and sequentially reducing towards an outlet of said air-coal mixture duct for partitioning said flow of air-coal mixture into said high-dense pulverized coal region and said low-dense pulverized coal region; inner and outer tubular sleeves encirclingly coupled with said air-coal mixture duct to form an inner secondary air duct and an outer secondary air duct, wherein said inner and outer secondary air ducts are arranged for partitioning a secondary air flow into an inner secondary air flow at said inner secondary air duct as an igniter for igniting said flow of air-coal mixture and an outer secondary air flow at said outer secondary air duct as an oxygen suppler for supplying enough oxygen for complete combustion of said flow of air-coal mixture, wherein a swirling direction of said inner secondary air flow at said inner secondary duct is the same as a swirling direction of said outer secondary air flow at said outer secondary duct, wherein said inner secondary air duct and said outer secondary air duct are coaxially formed with respect to said air-coal mixture duct such that said inner secondary air duct, said outer secondary air duct, and said air-coal mixture duct share a common axis; an inner secondary air damper supported at an inlet of said inner secondary air duct, wherein an opening valve of said inner secondary air damper is selectively adjusted to adjustably control an amount of said secondary air flow being partitioned into said inner secondary air duct and said outer secondary air duct, such that said high-dense pulverized coal region and said low-dense pulverized coal region of said flow of air-coal mixture mix with said inner and outer secondary air flows to form a moderate central recirculation zone for reducing an emission of NOx during combustion; an air-coal mixture conical outlet, an inner secondary air conical outlet, and an outer secondary air conical outlet, wherein an opening of said air-coal mixture conical outlet, with a smaller diameter, is coupled with said outlet of said air-coal mixture duct, wherein an opening of said inner secondary air conical outlet, with a smaller diameter, is coupled with an outlet of said inner secondary air duct, wherein an opening of said outer secondary air conical outlet, with a smaller diameter, is coupled with an outlet of said outer secondary air duct, wherein said conical outlets are arranged for delaying a mixing time of said flow of air-coal mixture with said inner and outer secondary air flows and to further prolong a residence time in the center recirculation zone so as to effectively reduce the formation of NOx, wherein said air-coal mixture conical outlet is extended inclinedly at an angle α with respect to a centerline of said air-coal mixture duct, wherein said inner secondary air conical outlet is extended inclinedly at an angle β with respect to said centerline of said air-coal mixture duct, wherein said outer secondary air conical outlet is extended inclinedly at an angle γ with respect to said centerline K of said air-coal mixture duct, wherein said angles α, β, γ are the same, wherein each of said angles α, β, γ has a threshold between 15° to 35°; an inner secondary air vane supported within said inner secondary air duct, wherein said inner secondary air vane is arranged for regulating said inner secondary air flow in a swirling manner before mixing with said flow of air-coal mixture mix, wherein said inner secondary air vane comprises a plurality of curved vane blades evenly and radially supported within said inner secondary air duct to regulate said inner secondary air flow in a swirling manner; and an outer secondary air vane supported at an inlet of said outer secondary air duct for regulating said outer secondary air flow in a swirling manner before mixing with said flow of air-coal mixture mix, wherein said outer secondary air vane comprises a set of flat vane blades and a regulator to selectively adjust a regulating angle of each of said flat vane blades, so as to regulate a swirl intensity of said outer secondary air flow. |
| Current U.S. Class: | 110/104B |
| Patent References Cited: | 1510645 October 1924 Bergman 4412496 November 1983 Trozzi 4428309 January 1984 Chang 4545307 October 1985 Morita et al. 5415114 May 1995 Monro et al. 5937770 August 1999 Kobayashi et al. 5979342 November 1999 Leisse et al. 6807914 October 2004 Leisse et al. 01217110 August 1989 |
| Assistant Examiner: | Laux, David J |
| Primary Examiner: | Rinehart, Kenneth |
| Attorney, Agent or Firm: | Chan, Raymond Y. David and Raymond Patent Firm |
| رقم الانضمام: | edspgr.08479668 |
| قاعدة البيانات: | USPTO Patent Grants |
| الوصف غير متاح. |