CN104864404A - Pulverized coal accumulation prevention fixing shrinkage cavity device with vertically-arranged primary air pipes for boiler coal pulverizing system - Google Patents
Pulverized coal accumulation prevention fixing shrinkage cavity device with vertically-arranged primary air pipes for boiler coal pulverizing system Download PDFInfo
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- CN104864404A CN104864404A CN201510285076.8A CN201510285076A CN104864404A CN 104864404 A CN104864404 A CN 104864404A CN 201510285076 A CN201510285076 A CN 201510285076A CN 104864404 A CN104864404 A CN 104864404A
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- pulverized coal
- shrinkage cavity
- air pipes
- primary air
- fixing shrinkage
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Abstract
The invention discloses a pulverized coal accumulation prevention fixing shrinkage cavity device with vertically-arranged primary air pipes for a boiler coal pulverizing system. The device comprises the vertically-installed primary pulverized coal air pipes and fixing shrinkage cavities formed in the primary pulverized coal air pipes. The upper end of each fixing shrinkage cavity is provided with a slope surface becoming wider from the edge of the cavity to the upper portion and forms a funnel-shaped pulverized coal accumulation prevention device through the slope surface. The device has the advantages that pulverized coal accumulation on the peripheries of the upper portions of the shrinkage cavities is avoided, and when existing, pulverized coal will slip off along the funnel-shaped pulverized coal accumulation prevention devices, so that pulverized coal accumulation is avoided; the device has a throttling effect, and the rotation speeds of the primary air pipes of a same-layer burner are controlled to be uniform; after the pulverized coal accumulation prevention fixing shrinkage cavity device is vertically installed, it is unnecessary to conduct a leveling test on the primary air pipes; the risk that pulverized coal deposits on the upper portions of the vertically-formed fixing shrinkage cavities and smolders to explode can be avoided; the vertically-installed pulverized coal accumulation prevention fixing shrinkage cavity device has wear resistance.
Description
Technical field
The present invention relates to the vertically arranged not accumulated powder of a kind of boiler milling system primary air piping and fix shrinkage cavity device, be applied to thermal power plant pulverized-coal fired boiler pulverized coal preparation system.
Background technology
Burner keeps suitable First air, Secondary Air and is separated burnout degree (OFA wind or SOFA wind) and exports even speed, is set up one of normal aerodynamic field and the necessary primary condition of smooth combustion.Too high can the postponement of primary air velocity is caught fire, too low then easy scaling loss burner, and in primary air piping, cause coal dust to deposit.The too high or too low normal hybrid perturbation that all may destroy air-flow of secondary wind speed.Thus reduce stability and the economy of burning.Being separated burnout degree is the fractional combustion wind controlling nitrogen oxide (NOx), within the specific limits, increases burnout degree and can reduce nitrogen oxide.Burnout degree affects boiler environmental-protecting performance.The size of burner outlet section and air velocity determine the percentage of primary air flow, secondary air flow and after-flame air quantity.This parameter is also that firing optimization needs to pay attention to.Especially primary air ratio, it and ignition process are closely related.Primary air ratio is larger, needing the heat of absorption just the more, thus reaching the required duration of catching fire just longer for reaching primary mixture ignition temperature.This fire coal low to volatile matter is very disadvantageous, more unfavorable when a wind-warm syndrome is lower.But, to the fire coal of high volatile, maintain fight not difficult, and after catching fire for ensure burning in time of volatile matter need higher primary air ratio.Boiler carries out needing when wind speed (air quantity) adjusts to consider security, economy and the feature of environmental protection.
In order to ensure boiler safety stabilize the economy environmental protection run, the layout of powder feeding pipes should make each powder feeding pipes air-flow and coal powder distribation even, the powder feeding pipes resistance of each burner should be as far as possible close, shrinkage cavity or other adjustment members can be installed if desired additional, by the shrinkage cavity on adjustment primary air piping, be not more than scholar 5% to make the deviate of the relative mean wind speed of each primary air piping maximum wind velocity.
Shrinkage cavity is the measure of a kind of fairly simple equal distribution stream and coal dust, and arrangement convenience, does not take up room.Shrinkage cavity mainly contains adjustable contraction and fixing shrinkage cavity two kinds.Adjustable contraction uses flexibly, as required, can carry out cold and hot state adjustment, but adjustment is complicated.Fixing shrinkage cavity structure is simple, do not need adjustment, but system needs accurate Calculation after installation, and when shrinkage cavity serious wear, pipeline enclosure allocation of the amount of air average deviation is comparatively large, when having a strong impact on stove combustion operating mode and boiler thermal output, needs to change shrinkage cavity orifice plate.
For 1000MW unit bituminous coal boiler, have 48 burners, combusting brown coal boiler-burner is more, if installation adjustable contraction adjustment workload is very large.Along with the development of Fluid Mechanics Computation technology, calculate accuracy and precision more and more higher, theory calculate meets completely installs fixing shrinkage cavity requirement.
Coal dust deposits in the duct for a long time and causes spontaneous combustion of pulverized coal, and coal dust temperature is higher, and spontaneous combustion is faster.Accumulated powder spontaneous combustion is the burning things which may cause a fire disaster producing blast.Therefore for preventing the blast of coal dust, should there is not projection and out-of-flatness place of retardance coal dust, avoid the deposition of coal dust in all another parts of pulverized coal preparation system.
Boiler coal-ash particle size great majority are less than 200 μm, and coal powder density is generally at 0.3kg/m
3~ 0.6kg/m
3between, be in and hold explosive dangerous concentrations scope most.
In boiler medium-speed pulverizer pulverized coal preparation system primary mixture, oxygen content is all greater than 14%, close to the oxygen amount in air, is in oxygen amount explosion ratio scope.
The shrinkage cavity of present use, when being especially arranged vertically, coal dust has a large amount of depositions.
Summary of the invention
Goal of the invention: the invention provides the vertically arranged not accumulated powder of a kind of boiler milling system primary air piping and fix shrinkage cavity device, object is to solve boiler milling system primary air piping vertically arranged shrinkage cavity accumulated powder problem.
Technical scheme: the present invention is achieved by the following technical solutions:
The vertically arranged not accumulated powder of a kind of boiler milling system primary air piping fixes shrinkage cavity device, it is characterized in that: this device comprises a vertically arranged coal dust airduct and is arranged on the fixing shrinkage cavity in a coal dust airduct, be provided with in the upper end of fixing shrinkage cavity along bore edges upwards gradually by narrow broaden domatic, this is domatic makes upper end of fixing shrinkage cavity form the anti-accumulated powder device of infundibulate.
Advantage and effect: the invention provides the vertically arranged not accumulated powder of a kind of boiler milling system primary air piping and fix shrinkage cavity device, the position of accumulated powder may be produced in order to control coal dust pipeline, avoid coal dust to deposit to set off an explosion, devise vertically arranged not accumulated powder and fix shrinkage cavity, accumulated powder is not fixed shrinkage cavity device and can be used and the fixing shrinkage cavity same metal material used now, or uses wear-resisting nonmetallic materials.
Advantage of the present invention is as follows:
The present invention avoids surrounding position, fixing shrinkage cavity top accumulated powder, can realize preventing accumulated powder along with funnel shaped anti-accumulated powder device landing when there being accumulated powder.
The present invention has throttling action, can control same grate firing burner each primary air piping speed even.
After the vertically arranged not accumulated powder of the present invention fixes shrinkage cavity device installation, primary air piping does not need to carry out leveling test.
The present invention can avoid vertically arranged fixing shrinkage cavity top accumulated powder to glow risk of explosion.
The vertically arranged not accumulated powder of the present invention is fixed shrinkage cavity device and is had wear-resistant feature.。
accompanying drawing illustrates:
Schematic diagram is arranged in the vertically arranged fixing shrinkage cavity that Fig. 1 uses now;
Fig. 2 is that schematic diagram is arranged in the vertically arranged fixing shrinkage cavity of the present invention's not accumulated powder.
detailed description of the invention:below in conjunction with accompanying drawing, the present invention is described further:
As shown in Figure 1, the invention provides the vertically arranged not accumulated powder of a kind of boiler milling system primary air piping and fix shrinkage cavity device, the fixing shrinkage cavity 2 that this device comprises a vertically arranged coal dust airduct 1 and is arranged in a coal dust airduct 1, be provided with in the upper end of fixing shrinkage cavity 2 along bore edges upwards gradually by narrow broaden domatic, this is domatic makes upper end of fixing shrinkage cavity 2 form the anti-accumulated powder device 3 of infundibulate.The domatic anti-accumulated powder device 3 of distinctive infundibulate realizes the object avoiding accumulated powder.
Claims (1)
1. the vertically arranged not accumulated powder of boiler milling system primary air piping fixes shrinkage cavity device, it is characterized in that: the fixing shrinkage cavity (2) that this device comprises a vertically arranged coal dust airduct (1) and is arranged in a coal dust airduct (1), be provided with in the upper end of fixing shrinkage cavity (2) along bore edges upwards gradually by narrow broaden domatic, this is domatic makes upper end of fixing shrinkage cavity (2) form the anti-accumulated powder device (3) of infundibulate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510285076.8A CN104864404A (en) | 2015-05-29 | 2015-05-29 | Pulverized coal accumulation prevention fixing shrinkage cavity device with vertically-arranged primary air pipes for boiler coal pulverizing system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510285076.8A CN104864404A (en) | 2015-05-29 | 2015-05-29 | Pulverized coal accumulation prevention fixing shrinkage cavity device with vertically-arranged primary air pipes for boiler coal pulverizing system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104864404A true CN104864404A (en) | 2015-08-26 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510285076.8A Pending CN104864404A (en) | 2015-05-29 | 2015-05-29 | Pulverized coal accumulation prevention fixing shrinkage cavity device with vertically-arranged primary air pipes for boiler coal pulverizing system |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2272755A (en) * | 1992-11-20 | 1994-05-25 | Northern Eng Ind | Pulverised fuel flow re-distributor |
| CN2793579Y (en) * | 2005-05-08 | 2006-07-05 | 钱震军 | Sinkhole adjusting mechanism with adjustable double core |
| CN200989596Y (en) * | 2006-12-28 | 2007-12-12 | 黄小平 | Direct-blowing powder-making system double-core adjustable cavity contracting valve |
| CN202048228U (en) * | 2011-05-12 | 2011-11-23 | 甘肃宏发电力工程技术有限公司 | Bidirectional adjustable shrinkage cavity device for pulverizing system powder tube of coal-fired unit |
| CN204880194U (en) * | 2015-05-29 | 2015-12-16 | 国家电网公司 | Not long -pending fixed shrinkage cavity system of powder that tuber pipe of boiler powder process system was arranged perpendicularly |
-
2015
- 2015-05-29 CN CN201510285076.8A patent/CN104864404A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2272755A (en) * | 1992-11-20 | 1994-05-25 | Northern Eng Ind | Pulverised fuel flow re-distributor |
| CN2793579Y (en) * | 2005-05-08 | 2006-07-05 | 钱震军 | Sinkhole adjusting mechanism with adjustable double core |
| CN200989596Y (en) * | 2006-12-28 | 2007-12-12 | 黄小平 | Direct-blowing powder-making system double-core adjustable cavity contracting valve |
| CN202048228U (en) * | 2011-05-12 | 2011-11-23 | 甘肃宏发电力工程技术有限公司 | Bidirectional adjustable shrinkage cavity device for pulverizing system powder tube of coal-fired unit |
| CN204880194U (en) * | 2015-05-29 | 2015-12-16 | 国家电网公司 | Not long -pending fixed shrinkage cavity system of powder that tuber pipe of boiler powder process system was arranged perpendicularly |
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Legal Events
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|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| EXSB | Decision made by sipo to initiate substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20150826 |
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| RJ01 | Rejection of invention patent application after publication |