CN214502124U - Magnesite low-nitrogen calcining device - Google Patents
Magnesite low-nitrogen calcining device Download PDFInfo
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- CN214502124U CN214502124U CN202120580263.XU CN202120580263U CN214502124U CN 214502124 U CN214502124 U CN 214502124U CN 202120580263 U CN202120580263 U CN 202120580263U CN 214502124 U CN214502124 U CN 214502124U
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Abstract
The utility model discloses a magnesite low-nitrogen calcining device, which comprises a calcining furnace body, wherein the bottom end of the calcining furnace body is provided with a first air inlet box body, a second air inlet box body, a third air inlet box body and a fourth air inlet box body, the top ends of the four air inlet box bodies are fixedly connected with the bottom end of the calcining furnace body, the first air inlet box body is in a cylindrical shell shape, and the first air inlet box body, the second air inlet box body, the third air inlet box body and the fourth air inlet box body are sequentially sleeved from inside to outside; the bottom end of the first air inlet box body is provided with a first air inlet, and the top end of the first air inlet box body is provided with a first flow through hole; the bottom end of the second air inlet box body is provided with a second air inlet and a third air inlet, and the top end of the second air inlet box body is provided with a second flow through hole; a fourth air inlet is formed in the bottom end of the third air inlet box body, and a third flow through hole is formed in the top end of the third air inlet box body; the bottom end of the fourth air inlet box body is provided with a fifth air inlet and a sixth air inlet, and the top end of the fourth air inlet box body is provided with a fourth circulation hole.
Description
Technical Field
The utility model relates to a mineral products processing field especially relates to a magnesite low-nitrogen calcining device.
Background
Magnesium oxide, as an important inorganic chemical product, has been widely used in various industries in China by virtue of its excellent physical properties such as high fire resistance and cohesiveness. Magnesite is one of the main production sources of magnesium oxide, has a very important position in the mineral resource boundary of China, and the magnesite stock quantity which is already discovered in China is about 35 hundred million tons and accounts for about 25 percent of the total stock quantity of the world, so that China becomes the largest magnesite producing country and export country in the world. The magnesite has wide application, and is widely applied to the industrial fields of refractory materials, metallurgical ironmaking industry, novel fireproof building materials, magnesium metal extraction, chemical industry and the like at present. With the increasing demand of industries such as metallurgy, refractory materials, building materials, environmental protection desulfurization, feed and the like on magnesium oxide, people pay attention to how to efficiently and environmentally calcine magnesium oxide by magnesite.
In the existing process for producing magnesium oxide by calcining magnesite, producer gas and natural gas are mainly used as heat supply raw materials, and the temperature of a hearth is about 1100 ℃. Due to the complex reasons of high-temperature calcination, raw material decomposition, relatively concentrated high-temperature sections and the like in the furnace, a large amount of NOx is generated in the furnace, the tail end emission of flue gas NOx exceeds the standard, and the emission concentration is more than 300mg/m 3. A large amount of NOx can damage an ozone layer, enhance the oxidability of the atmosphere, form hazy and acid rain and other dangerous weather, bring serious harm to production and life of people, and magnesite low-nitrogen calcined magnesia is imperative.
At present, a conventional calciner is basically adopted in a calcining process of magnesite, fuel and combustion-supporting air are not reasonably controlled, the atmosphere in the calciner is uncontrollable, a large amount of NOx is generated in the combustion process due to the existence of a local high-temperature zone and the like, the content of NOx in tail-end discharged smoke exceeds the standard, and certain pollution is caused to the atmosphere; meanwhile, the fuel consumption is relatively high, and the energy waste is caused.
Although some large and medium-sized enterprises adopt the SCR denitration technology or the low-temperature oxidation denitration technology, the SCR denitration technology has high initial investment and operation cost, the flue gas is filled with metal oxides which may cause catalyst poisoning and blockage, and the secondary pollution problem of catalyst treatment and the ammonia escape problem exist at the same time; and the denitration efficiency of the low-temperature oxidation denitration technology is not high, so that the environmental protection requirement is hardly met. And the technologies and the methods all belong to terminal treatment technologies, so that the technology and the equipment for burning gas fuel have poor denitration economy, high enterprise operation cost and still serious denitration and emission reduction situation.
Disclosure of Invention
The utility model aims at the above-mentioned problem, provide a low nitrogen calcining device of magnesite of simple structure, reduction NOx discharge.
In order to realize the purpose, the technical scheme of the utility model is that:
a magnesite low-nitrogen calcining device comprises a calcining furnace body, wherein a first air inlet box body, a second air inlet box body, a third air inlet box body and a fourth air inlet box body are arranged at the bottom end of the calcining furnace body, the top ends of the first air inlet box body, the second air inlet box body, the third air inlet box body and the fourth air inlet box body are fixedly connected with the bottom end of the calcining furnace body, the first air inlet box body is in a cylindrical shell shape, the second air inlet box body, the third air inlet box body and the fourth air inlet box body are in an annular shell shape, and the first air inlet box body, the second air inlet box body, the third air inlet box body and the fourth air inlet box body are sequentially sleeved from inside to outside; the bottom end of the first air inlet box body is provided with a first air inlet, and the interior of the first air inlet box body is communicated with the interior of the calcining furnace body through a first flow through hole; the bottom end of the second air inlet box body is provided with a second air inlet and a third air inlet, and the interior of the second air inlet box body is communicated with the interior of the calcining furnace body through a second flow through hole; a fourth air inlet is formed in the bottom end of the third air inlet box body, and the interior of the third air inlet box body is communicated with the interior of the calcining furnace body through a third through hole; and a fifth air inlet and a sixth air inlet are formed in the bottom end of the fourth air inlet box body, and the inside of the fourth air inlet box body is communicated with the inside of the calcining furnace body through a fourth circulation hole.
Furthermore, the bottom end of the calcining furnace body is arc-shaped.
Furthermore, a plurality of first flow through holes, a plurality of second flow through holes, a plurality of third flow through holes and a plurality of fourth flow through holes are arranged on the end face of the bottom end of the calcining furnace body at equal intervals in an annular shape; the plurality of second flow through holes are arranged on the outer sides of the circumferences of the plurality of first flow through holes in a ring shape; the plurality of third flow through holes are arranged on the outer sides of the circumferences of the plurality of second flow through holes in a ring shape; the plurality of fourth circulation holes are arranged on the outer sides of the circumferences of the plurality of third circulation holes in a ring shape.
Further, first air inlet sets up in first air inlet box bottom one side, and second air inlet, third air inlet set up respectively in second air inlet box bottom side, and the fourth air inlet sets up in third air inlet box bottom one side, and fifth air inlet, sixth air inlet all set up in fourth air inlet box bottom one side and fifth air inlet and sixth air inlet are linked together.
Furthermore, the first flow through hole and the second flow through hole are arranged in an inclined manner, and included angles of 0-30 degrees are formed between the axis of the first flow through hole and the axis of the second flow through hole and the axis of the calcining furnace body.
Compared with the prior art, the utility model has the advantages and positive effect be:
when the utility model is used, different air inlets are used for the operation of graded and graded air inlet, the atmosphere in the furnace is accurately controlled through graded air supply, and the generation of NOx in the furnace is greatly reduced; meanwhile, fuel is sprayed into the calcining furnace body in a rotational flow mode, fuel gas forms rotary jet flow in the calcining furnace after being sprayed out, surrounding combustion-supporting air is stirred, the fuel and the air are uniformly mixed to form uniform combustion, and a local high-temperature area is not formed during combustion, so that the generation of NOx is inhibited; in addition, the utility model adopts an air inlet as a circulating flue gas inlet which is used for refluxing partial flue gas in the tail flue of the calcining furnace body to participate in combustion as oxygen-poor combustion-supporting gas, so as to adjust and control the oxygen concentration in the hearth and further reduce the generation of NOx; meanwhile, the plurality of circulation holes are designed to be annularly distributed, so that fuel, air and circulating flue gas are divided into a plurality of fine streams in the combustion process, the combustion is uniform, and the generation of NOx is further inhibited; the utility model discloses simple structure, low cost has effectively reduced the formation volume of NOx in the magnesite calcination production process to atmospheric environment has been protected to a certain extent.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.
Fig. 1 is a schematic structural view of the present invention;
FIG. 2 is a sectional plan view of the calciner body.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, any modifications, equivalent replacements, improvements, etc. made by other embodiments obtained by a person of ordinary skill in the art without creative efforts shall be included in the protection scope of the present invention.
As shown in fig. 1 and fig. 2, the embodiment discloses a magnesite low-nitrogen calcining device, which includes a calcining furnace body 1, wherein the bottom end of the calcining furnace body 1 is arc-shaped; the bottom end of the calcining furnace body 1 is provided with a first air inlet box body 2, a second air inlet box body 3, a third air inlet box body 4 and a fourth air inlet box body 5, the top ends of the first air inlet box body 2, the second air inlet box body 3, the third air inlet box body 4 and the fourth air inlet box body 5 are fixedly connected with the bottom end of the calcining furnace body 1, the first air inlet box body 2 is in a cylindrical shell shape, the second air inlet box body 3, the third air inlet box body 4 and the fourth air inlet box body 5 are in an annular shell shape, and the first air inlet box body 2, the second air inlet box body 3, the third air inlet box body 4 and the fourth air inlet box body 5 are sequentially sleeved from inside to outside; namely, the second air inlet box body 3 is sleeved outside the first air inlet box body 2, the third air inlet box body 4 is sleeved outside the second air inlet box body 3, and the fourth air inlet box body 5 is sleeved outside the third air inlet box body 4;
the bottom end of the first air inlet box body 2 is provided with a first air inlet 201, and the interior of the first air inlet box body 2 is communicated with the interior of the calcining furnace body 1 through a first flow through hole 202 arranged at the bottom end of the calcining furnace body 1; the bottom end of the second air inlet box body 3 is provided with a second air inlet 301 and a third air inlet 302, and the inside of the second air inlet box body 3 is communicated with the inside of the calcining furnace body 1 through a second flow through hole 303 arranged at the bottom end of the calcining furnace body 1; a fourth air inlet 401 is arranged at the bottom end of the third air inlet box body 4, and the inside of the third air inlet box body 4 is communicated with the inside of the calcining furnace body 1 through a third through hole 402 arranged at the bottom end of the calcining furnace body 1; a fifth air inlet 501 and a sixth air inlet 502 are arranged at the bottom end of the fourth air inlet box body 5, the fifth air inlet 501 is communicated with the sixth air inlet 502, and each air inlet is provided with a control valve for convenient control; the inside of the fourth inlet box 5 is communicated with the inside of the calciner body 1 through a fourth flow hole 503.
A plurality of first flow through holes 202, a plurality of second flow through holes 303, a plurality of third flow through holes 402 and a plurality of fourth flow through holes 503 are arranged on the end face of the bottom end of the calcining furnace body 1 at equal intervals in a ring shape; the plurality of second flow through holes 303 are arranged outside the circumference of the plurality of first flow through holes 202 in a ring shape; the first flow through hole 202 and the second flow through hole 303 are arranged in an inclined shape, and the axial line of the first flow through hole 202 and the axial line of the second flow through hole 303 form an included angle of 0-30 degrees with the axial line of the calcining furnace body 1; the plurality of third flow through holes 402 are arranged outside the circumference of the plurality of second flow through holes 303 in a ring shape; the plurality of fourth flow holes 503 are arranged in a ring shape outside the circumference of the plurality of third flow holes 402.
The utility model discloses a mode of "air classification + fuel whirl + flue gas extrinsic cycle" carries out the burning of fuel, reduces NOx's production in fuel combustion process to reach the emission to reach standard of flue gas.
When magnesite is calcined, the temperature in the furnace is about 1100 ℃, fuel type NOx is mainly in the furnace, and the excess air coefficient is accurately regulated and controlled by adopting air staged combustion, namely, the oxygen deficiency in the main combustion zone is kept, so that the generation amount of the NOx can be greatly reduced by burning the main combustion zone in a reducing atmosphere. The combustion air required by fuel combustion is fed in three stages by an air classification technology, primary air is fed in 10-30% of the total air required by the primary air, fuel is ignited, secondary air is fed in 50-80% of the total air required by the secondary air, air required by ignition and primary combustion of the fuel is provided, and tertiary air is fed in 10-30% of the total air required by the tertiary air, and air required by further combustion of the fuel in a hearth is provided. Through the graded feeding of air, the atmosphere in the furnace is accurately controlled, and the generation of NOx in the furnace is greatly reduced.
The fuel rotational flow refers to that when fuel is supplied to the calcining furnace, the fuel is sprayed out in a rotational flow mode through a nozzle which is arranged on a fuel spraying channel and forms an angle of 0-30 degrees with the axis of the calcining furnace, when the fuel is sprayed out, a rotary jet flow can be formed, surrounding combustion-supporting air is stirred, the fuel and the air are uniformly mixed to form uniform combustion, and a local high-temperature area is not formed during the combustion, so that the generation of NOx is inhibited.
In order to reduce the air consumption coefficient of combustion process, the utility model discloses extract partial flue gas in the afterbody flue after the dust removal desulfurization, introduce the burning furnace, participate in the burning as oxygen-poor combustion-supporting gas, the oxygen concentration in the adjustment control furnace further reduces NOx's formation.
The calcining device is a dual-purpose calcining furnace for generator gas and natural gas, and the pressure of the generator gas or the natural gas is 3 kPa-10 kPa; when the calcining furnace uses natural gas as fuel, the first air inlet is a natural gas inlet, the second air inlet is a primary air inlet, the third air inlet is closed, the fourth air inlet is a secondary air inlet, the fifth air inlet is a tertiary air inlet, and the sixth air inlet is a circulating flue gas inlet;
when the producer gas is used as fuel in the calcining furnace, the first gas inlet is a primary air inlet, the second gas inlet is closed, the third gas inlet is a producer gas inlet, the fourth gas inlet is a secondary air inlet, the fifth gas inlet is a tertiary air inlet, and the sixth gas inlet is a circulating flue gas inlet;
the gas and air jet ports of the calciner are all arranged in a circumferential manner, when the calciner is used, mixed gas of primary air, secondary air, tertiary air and circulating flue gas is jetted by the plurality of circumferentially distributed jet ports, so that in the combustion process, the fuel, the air and the circulating flue gas are divided into a plurality of fine streams which are combusted while rotating, the combustion is uniform, no local high-temperature region exists, and the generation of NOx is well inhibited by means of the oxygen-deficient atmosphere formed by the circulating flue gas.
The smoke circulation mode is a forced circulation mode outside the furnace, the smoke circulation mode is supplied to the calcining furnace from the sixth air inlet and is mixed with the tertiary air supplied from the fifth air inlet to participate in the combustion process, so that the fuel gas is burnt out, the combustion efficiency is improved, meanwhile, the amount of the smoke extracted can be controlled through the frequency conversion of the smoke circulation fan or the adjusting valve, the smoke circulation amount is stable and easy to control, a stable oxygen-poor atmosphere can be formed in the hearth, the generation of NOx is effectively inhibited, the pollution degree of magnesite calcining work to the atmospheric environment is effectively reduced, and convenience is brought to the magnesite calcining work.
Claims (5)
1. The utility model provides a magnesite low nitrogen calcining device, includes the calciner body, its characterized in that: the bottom end of the calcining furnace body is provided with a first air inlet box body, a second air inlet box body, a third air inlet box body and a fourth air inlet box body, the top ends of the first air inlet box body, the second air inlet box body, the third air inlet box body and the fourth air inlet box body are fixedly connected with the bottom end of the calcining furnace body, the first air inlet box body is in a cylindrical shell shape, the second air inlet box body, the third air inlet box body and the fourth air inlet box body are in an annular shell shape, and the first air inlet box body, the second air inlet box body, the third air inlet box body and the fourth air inlet box body are sequentially sleeved from inside to outside; the bottom end of the first air inlet box body is provided with a first air inlet, and the interior of the first air inlet box body is communicated with the interior of the calcining furnace body through a first flow through hole; the bottom end of the second air inlet box body is provided with a second air inlet and a third air inlet, and the interior of the second air inlet box body is communicated with the interior of the calcining furnace body through a second flow through hole; a fourth air inlet is formed in the bottom end of the third air inlet box body, and the interior of the third air inlet box body is communicated with the interior of the calcining furnace body through a third through hole; and a fifth air inlet and a sixth air inlet are formed in the bottom end of the fourth air inlet box body, and the inside of the fourth air inlet box body is communicated with the inside of the calcining furnace body through a fourth circulation hole.
2. The magnesite low-nitrogen calcination device of claim 1, wherein: the bottom end of the calcining furnace body is arc-shaped.
3. The magnesite low-nitrogen calcination device of claim 2, wherein: the first flow through holes, the second flow through holes, the third flow through holes and the fourth flow through holes are all provided with a plurality of annular first flow through holes which are arranged on the end surface of the bottom end of the calcining furnace body at equal intervals; the plurality of second flow through holes are arranged on the outer sides of the circumferences of the plurality of first flow through holes in a ring shape; the plurality of third flow through holes are arranged on the outer sides of the circumferences of the plurality of second flow through holes in a ring shape; the plurality of fourth circulation holes are arranged on the outer sides of the circumferences of the plurality of third circulation holes in a ring shape.
4. The magnesite low-nitrogen calcination device of claim 3, wherein: the first air inlet is arranged on one side of the bottom end of the first air inlet box body, the second air inlet and the third air inlet are respectively arranged on the side face of the bottom end of the second air inlet box body, the fourth air inlet is arranged on one side of the bottom end of the third air inlet box body, and the fifth air inlet and the sixth air inlet are respectively arranged on one side of the bottom end of the fourth air inlet box body and are communicated with each other.
5. The magnesite low-nitrogen calcination device of claim 4, wherein: the first flow through hole and the second flow through hole are arranged in an inclined mode, and included angles of 0-30 degrees are formed between the axis of the first flow through hole and the axis of the second flow through hole and the axis of the calcining furnace body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120580263.XU CN214502124U (en) | 2021-03-22 | 2021-03-22 | Magnesite low-nitrogen calcining device |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120580263.XU CN214502124U (en) | 2021-03-22 | 2021-03-22 | Magnesite low-nitrogen calcining device |
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| CN214502124U true CN214502124U (en) | 2021-10-26 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202120580263.XU Active CN214502124U (en) | 2021-03-22 | 2021-03-22 | Magnesite low-nitrogen calcining device |
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- 2021-03-22 CN CN202120580263.XU patent/CN214502124U/en active Active
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