CN115790144B - Device system and method for recycling nitrogen of roller kiln - Google Patents
Device system and method for recycling nitrogen of roller kiln Download PDFInfo
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Abstract
The invention provides a device system and a method for recycling nitrogen of a roller kiln, wherein the device system comprises: a first gas outlet arranged in the constant temperature area of the kiln body; the first air supply device, the cooling device, the dust removing device and the oxygen concentration detecting device are connected with the first gas outlet through a nitrogen pipeline in sequence; the oxygen concentration detection device is connected with the nitrogen inlet of the kiln body through a nitrogen pipeline. The method comprises the steps of extracting gas to be recovered from a first gas outlet by using a first air supply device, cooling the gas to be recovered through a cooling device and removing dust through a dust removing device in sequence to obtain recovered nitrogen, and circularly conveying the recovered nitrogen into a constant temperature area and a cooling area of a kiln body after detecting that the oxygen concentration reaches a standard range. The invention can recycle nitrogen in the roller kiln, and solves the technical problems of waste of a large amount of nitrogen, waste of resources caused by generating nitrogen oxide compounds by combustion, environmental pollution and the like in the prior art.
Description
Technical Field
The invention relates to the technical field of waste gas separation, recovery and recycling, in particular to a device system and a method for recycling nitrogen in a roller kiln.
Background
At present, the lithium ion battery is applied to continuous expansion, the important component of the lithium ion battery, namely the positive electrode material, is required to be sintered in production and processing, and at present, the lithium ion positive electrode material is not only lithium iron phosphate but also ternary positive electrode material, and the sintering equipment is basically a roller kiln.
The roller kiln comprises a kiln body, an automatic line body and a deodorizing furnace, all gases in the kiln body are pumped into the deodorizing furnace through an air supply device by the traditional roller kiln, natural gas and air are pumped into the kiln for combustion and then are discharged, for example CN216592724U discloses a lithium battery anode material carbonization production roller kiln, the roller kiln comprises a conveying roller way and an inlet section, a heating section, a constant temperature section, a cooling section and an outlet section, the conveying roller way sequentially passes through the inlet section, the heating section is also provided with a waste gas treatment section, the waste gas treatment section is communicated with the heating section, the inlet section is provided with an inlet replacement chamber, a sagger enters from the inlet replacement chamber, the cooling section is provided with a heat dissipation chamber, a cooling water pipe and a cooling air pipe, the waste gas treatment section is communicated with the heating section through a flue gas pipeline, and flue gas generated by the heating section can enter the waste gas treatment section through the flue gas pipeline.
More than 99% of nitrogen in the kiln is discharged outside the kiln and cannot be reused, and a large amount of natural gas is required for combustion, so that nitrogen oxide compounds are generated, resource waste is caused, and the environment is polluted.
Therefore, there is a need to develop a new technology to solve the problems of nitrogen waste and environmental pollution.
CN209221808U discloses a device for treating waste gas and utilizing waste heat in a lithium ion battery cathode material production line, which comprises a roller kiln, wherein one end of the roller kiln is connected with a gas inlet, the other end of the roller kiln is connected with an adsorption device through a pipeline, the adsorption device is used for conveying waste gas in the roller kiln to the adsorption device, and the adsorption device is connected with a first exhaust pipe for exhausting tail gas; the device comprises a heat exchanger, and is characterized by further comprising a heat exchanger, wherein one end of the heat exchanger is connected with an adsorption device through a pipeline, high-temperature nitrogen in the adsorption device is conveyed to the heat exchanger through a pipeline, and the other end of the heat exchanger is also provided with a nitrogen inlet for conveying new nitrogen into the heat exchanger, and the new nitrogen and the high-temperature nitrogen exchange heat in the heat exchanger; the heat exchanger is communicated with the gas inlet and is used for conveying the heated fresh nitrogen into the roller kiln; the heat exchanger is also connected with a second exhaust pipe for discharging the cooled high-temperature nitrogen.
CN208595823U discloses an intelligent energy-saving roller kiln, the upper furnace body of the roller kiln is provided with an exhaust pipe and an exhaust collecting pipe, a plurality of rows of cold gas inlet pipes which are arranged in a U shape are arranged in the exhaust collecting pipe, the straight pipe parts of the cold gas inlet pipes are connected with the air inlet collecting pipe after coming out of the exhaust collecting pipe, air inlet branch pipes are distributed on the air inlet collecting pipe, and a high temperature resistant gas flowmeter, a temperature sensor, a pressure sensor, a high temperature resistant control valve and a computer provided with control software are arranged on the air inlet branch pipes and are connected with each other, and the air inlet branch pipes enter the roller kiln again.
However, the device and the process are not related to recycling of nitrogen, only the utilization of waste heat is related, and the problems of nitrogen resource waste and environmental pollution after combustion still exist.
Disclosure of Invention
In view of the problems in the prior art, the invention provides a device system and a method for recycling nitrogen in a roller kiln, which can recycle nitrogen after simple cooling and dust removal treatment by leading nitrogen out from a constant temperature zone of the roller kiln, thereby avoiding the waste of nitrogen resources.
To achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a device system for recycling nitrogen in a roller kiln, the device system comprising:
a first gas outlet arranged in the constant temperature area of the kiln body;
the first air supply device, the cooling device, the dust removing device and the oxygen concentration detecting device are connected with the first gas outlet through a nitrogen pipeline in sequence;
the oxygen concentration detection device is connected with the nitrogen inlet of the kiln body through a nitrogen pipeline.
According to the invention, the first gas outlet is arranged in the constant temperature area of the kiln body, the gas is extracted, the purity of the extracted gas nitrogen is high, the nitrogen can be recycled after passing through the cooling device and the dust removing device, and the nitrogen recycling rate is more than 95%. The device system provided by the invention is simply improved on the basis of the original roller kiln, and the improvement proposal is feasible.
The present invention has no special requirement on the dust removing device, and the dust removing device can be used as is well known by the person skilled in the art, such as a cloth bag dust remover, etc., and the person skilled in the art can use any one of primary dust removing, medium-efficiency dust removing or high-efficiency dust removing according to the characteristics of the production of the anode material, and has no special limitation.
Preferably, an inner coating layer is provided on the inner side of the first air supply device.
Preferably, the material of the inner coating is teflon.
Preferably, the nitrogen pipe comprises a stainless steel pipe.
Preferably, an insulating layer is arranged on the outer side of the nitrogen pipeline.
Preferably, the material of the heat-insulating layer comprises aluminum silicate cotton and the like.
Preferably, the cooling device comprises a coil air cooling device or a coil water cooling device. The invention can recycle the waste heat in the gas to be recycled through the coil air cooling device or the coil water cooling device.
Preferably, the cooling device and the dust removing device are both airtight devices.
Preferably, the plant system further comprises a first valve arranged between the oxygen concentration detection device and the nitrogen inlet of the kiln body.
Preferably, the apparatus system further comprises a second valve disposed between the first air supply means and the first gas outlet.
Preferably, the second valve is a throttle valve.
Preferably, the device system further comprises a first control system for controlling the open/close state of the first valve and/or the second valve according to the oxygen concentration value detected by the oxygen concentration detection device.
The roller kiln is mainly used for producing lithium iron phosphate positive electrode materials, ternary positive electrode and other positive electrode materials of lithium ion batteries, and the requirements on oxygen concentration in the production process of the positive electrode materials are strict.
Preferably, the device system further comprises a nitrogen gas further exhaust pipeline connected with the oxygen concentration detection device.
The invention preferably provides a nitrogen additional discharge pipeline, and when the oxygen concentration detection is not qualified, the nitrogen can be discharged into the air or can be discharged to other industrial applications.
Preferably, the kiln body sequentially comprises a heating region, a constant temperature region and a cooling region from the furnace end to the furnace tail.
Preferably, the length of the heating zone accounts for 18-27% of the length of the kiln body, for example, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26% or 27% of the length of the kiln body.
Preferably, the length of the constant temperature zone accounts for 36-46% of the length of the kiln body, for example, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45% or 46% and the like.
Preferably, the length of the cooling area accounts for 27-36% of the length of the kiln body, for example, 27%, 28%, 29%, 30%, 31%, 32%, 34%, 35% or 36% of the length of the kiln body.
Preferably, the first gas outlet is arranged at one end of the constant temperature zone close to the temperature rising zone.
Preferably, the distance between the first gas outlet and the temperature raising region is 7.7-23% of the constant temperature region, for example, 7.7%, 8%, 9%, 10%, 12%, 15%, 18%, 20%, 22% or 23% may be used.
The extraction position of the first gas outlet is very critical, because the kiln body of the roller kiln does not only contain nitrogen, but also small molecular organic matters are generated in the calcining process of the anode material of the heating zone, so that the gas of the heating zone cannot be simply cooled and filtered and then recovered, the purity of the nitrogen of the constant temperature zone and the cooling zone is still higher after the nitrogen is used as protective gas, the kiln body is provided with a gas communicated channel, the high-purity nitrogen is required to protect the anode material in the follow-up constant temperature zone and cooling zone, and when the first gas outlet is added in the constant temperature zone and the first air supply device is arranged, the gas flow direction in the whole kiln body is influenced, and the gas of the heating zone is easily led to be in the constant temperature zone and the cooling zone to influence the production of the anode material product; in order to overcome the defects, the invention preferably controls the distance between the first gas outlet and the temperature rising area to account for 7.7-23% of the constant temperature area, so that on one hand, the arrangement can prevent the gas in the temperature rising area from being connected into the constant temperature area and the temperature reducing area to affect the production of the anode material product, on the other hand, the utilization rate of nitrogen and the quality of the recovered nitrogen can be improved, the cost of nitrogen recovery treatment is reduced, and the aim of efficiently recovering the nitrogen is achieved.
Preferably, the first gas outlet is provided with at least 1, for example, 1, 2 or 3, etc., preferably at least 2. The invention further preferably provides at least two first gas outlets, so that the furnace pressure in the roller kiln can be balanced better, the recovery rate of nitrogen is higher, and the whole production is safer.
Preferably, the device system further comprises a first pressure detector arranged at the first gas outlet and a second pressure detector arranged at the second gas outlet.
Preferably, the plant system further comprises a third pressure detector arranged inside the kiln body.
The third pressure detector can monitor the pressure in the kiln body in real time, thereby guaranteeing the pressure condition of the production of the anode material.
Preferably, the heating zone of the kiln body is provided with a second gas outlet.
Preferably, the second gas outlet is connected to a deodorizing device.
Preferably, a second air supply device is further arranged between the second air outlet and the deodorizing device.
Preferably, the device system further comprises a second control system for regulating and controlling any one or at least two of the power of the first air supply device, the power of the second air supply device or the opening degree of the second valve according to the pressure values detected by the first pressure detector and the second pressure detector.
The pressure detection device is preferably arranged in the kiln body, the pressure in the kiln body is monitored in real time, the power control of the first air supply device and the second air supply device is facilitated, the air is prevented from being connected in series, and the production of the anode material is guaranteed better.
Preferably, at least one nitrogen inlet is arranged at the bottoms of the constant temperature area and the temperature reduction area of the kiln body.
Preferably, the cooling zone, the constant temperature zone and the cooling zone are each independently provided with at least two temperature zones.
In a second aspect, the invention provides a method for recycling nitrogen in a roller kiln, which is performed by adopting the device system for recycling nitrogen in the roller kiln in the first aspect.
The nitrogen recycling method provided by the second aspect of the invention can safely and efficiently recycle the nitrogen in the constant temperature area and the cooling area, and simultaneously recycle the waste heat in the nitrogen, thereby reducing the production cost of the cathode material.
Preferably, the method comprises: and nitrogen is introduced into the constant temperature area and the cooling area of the kiln body. The first air supply device extracts gas to be recovered from the first gas outlet, the gas to be recovered is cooled by the cooling device and is dedusted by the dedusting device in sequence to obtain recovered nitrogen, and the recovered nitrogen is circularly fed into the constant temperature area and the cooling area of the kiln body after the oxygen concentration of the recovered nitrogen reaches the standard range through the oxygen concentration detection device.
According to the invention, the gas is extracted from the first gas outlet, the purity of the extracted gas nitrogen is high, the nitrogen can be recycled after passing through the cooling device and the dust removing device, and the nitrogen recycling rate is more than 95%.
Preferably, the cooling and dust removal processes are performed in a closed environment.
The invention needs to strictly ensure the airtight space in cooling and dust removal and prevents the introduction of oxygen.
Preferably, the pressure in the kiln body is maintained to be less than or equal to 150Pa, such as 150Pa, 140Pa, 130Pa, 120Pa, 110Pa, 100Pa, 90Pa, 80Pa, etc.
Preferably, the final temperature of the cooling is less than or equal to 200 ℃, and can be 200 ℃, 190 ℃, 180 ℃, 170 ℃, 160 ℃, 150 ℃, 120 ℃ or the like.
The invention needs to reduce the temperature of the gas to be recovered to below 200 ℃ firstly, otherwise, the cost of the follow-up dust removing device is greatly increased.
Preferably, the standard range is 50ppm or less, and may be, for example, 50ppm, 40ppm, 30ppm, 20ppm, 10ppm, or the like.
Preferably, when the oxygen concentration of the recovered nitrogen gas detected by the oxygen concentration detection device does not reach the standard range, the first control system closes the first valve and the second valve, and discharges the nitrogen gas in the nitrogen gas pipeline through the nitrogen gas other pipeline.
Preferably, the first control system closes the first valve first and then closes the second valve.
Preferably, the second air supply device extracts the gas to be deodorized from the second gas outlet and sends the gas to the deodorization device for deodorization treatment.
Preferably, the wind pressure of the first gas outlet is smaller than the wind pressure of the second gas outlet.
Preferably, the wind pressure of the first gas outlet is 1 to 100Pa smaller than the wind pressure of the second gas outlet, and may be, for example, 1Pa, 5Pa, 10Pa, 15Pa, 20Pa, 25Pa, 30Pa, 35Pa, 40Pa, 50Pa, 60Pa, 70Pa, 80Pa, 90Pa, or 100 Pa.
The invention has the difficulty of ensuring that the second gas outlet can extract all the gas in the heating zone, thereby avoiding the condition that the product line cannot continue to be produced due to the fact that the air in the heating zone is introduced into the constant temperature zone and the cooling zone, ensuring the pressure in the kiln body and ensuring that the wind pressure of the second gas outlet is slightly larger than the wind pressure of the first gas outlet. According to the invention, the air pressure of the first gas outlet is preferably controlled to be 1-100 Pa smaller than the air pressure of the second gas outlet, preferably 5-70 Pa smaller, so that the recycling rate of nitrogen can be ensured.
Preferably, the second control system monitors that the difference between the wind pressure of the first gas outlet and the wind pressure of the second gas outlet is not within a set range, and adjusts any one or a combination of at least two of the power of the second air supply device, the power of the first air supply device, or the opening degree of the second valve.
The invention additionally comprises a second control system which can adjust the power of the first air supply device, the power of the second air supply device and the opening of the second valve in real time, thereby ensuring the safe operation of the whole device.
As a preferred embodiment of the present invention, the method includes:
and nitrogen is introduced into the constant temperature area and the cooling area of the kiln body. The first air supply device extracts gas to be recovered from a first gas outlet, the gas to be recovered is cooled to less than or equal to 200 ℃ through the cooling device in sequence and is dedusted through the dedusting device to obtain recovered nitrogen, the recovered nitrogen is circularly sent into a constant temperature area and a cooling area of the kiln body after the oxygen concentration detection device detects that the oxygen concentration is less than or equal to 50ppm, and when the oxygen concentration of the recovered nitrogen is less than or equal to 50ppm through the oxygen concentration detection device, the first control system firstly closes a first valve, then closes a second valve, and discharges the nitrogen in a nitrogen pipeline through another nitrogen pipeline;
the second air supply device extracts the gas to be deodorized from the second gas outlet and sends the gas to the deodorization device for deodorization treatment; the wind pressure of the first gas outlet is smaller than that of the second gas outlet; the wind pressure of the first gas outlet is 5-15 Pa smaller than that of the second gas outlet; and when the difference between the wind pressure of the first gas outlet and the wind pressure of the second gas outlet is not in the set range, the second control system adjusts any one or the combination of at least two of the power of the second air supply device, the power of the first air supply device and the opening of the second valve.
The present invention is not particularly limited to the process for producing the positive electrode material and the manner of deodorizing treatment in the above-described process, and any manner and apparatus known to those skilled in the art to be useful for producing the positive electrode material and deodorizing treatment may be employed.
Compared with the prior art, the invention has at least the following beneficial effects:
(1) The device system for recycling the nitrogen of the roller kiln provided by the invention can be better improved on the basis of the original roller kiln, the transformation cost is low, only 20-100 ten thousand yuan is needed by adding a set of device system for recycling the nitrogen, and the transformation period is short and is only 30-60 days; and about 6 months are needed for building a new roller kiln;
(2) According to the device system for recycling the nitrogen of the roller kiln, the first control system and the second control system are preferably arranged, so that the device system can stably and safely run;
(3) The method for recycling the nitrogen in the roller kiln provided by the invention can realize recycling of more than 99% of the nitrogen, can save about 310 ten thousand cubic meters of nitrogen for 4500 tons of anode material produced in one year, and can save natural gas cost required by nitrogen combustion, and the total cost is saved by more than 615 ten thousand yuan.
Drawings
Fig. 1 is a system diagram of a device for recycling nitrogen in a roller kiln provided in embodiment 1 of the present invention.
Fig. 2 is a roller kiln diagram provided in comparative example 1 of the present invention.
In the figure: 1-a first gas outlet; 2-a first air supply device; 3-a cooling device; 4-a dust removal device; 5-an oxygen concentration detection means; 6, kiln body; 61-heating zone; 62-a constant temperature zone; 63-a cooling zone; 7-a second gas outlet; 8-a second air supply device; 9-deodorization device.
Detailed Description
The technical scheme of the invention is further described below by the specific embodiments with reference to the accompanying drawings.
The present invention will be described in further detail below. The following examples are merely illustrative of the present invention and are not intended to represent or limit the scope of the invention as defined in the claims.
It is to be understood that in the description of the present invention, the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus are not to be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", etc. may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.
It should be noted that, in the description of the present invention, unless explicitly specified and limited otherwise, the terms "disposed," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art in a specific case.
It will be appreciated by those skilled in the art that the present invention necessarily includes the necessary piping, conventional valves and general pumping equipment for achieving the process integrity, but the foregoing is not a major inventive aspect of the present invention, and that the present invention is not particularly limited thereto as the layout may be added by themselves based on the process flow and the equipment configuration options.
Example 1
The embodiment provides a device system for recycling nitrogen in a roller kiln, as shown in fig. 1, the device system comprises:
a first gas outlet 1 arranged in a constant temperature zone 62 of the kiln body 6; the first air supply device 2, the cooling device 3, the dust removing device 4 and the oxygen concentration detecting device 5 are connected with the first gas outlet 1 sequentially through a nitrogen pipeline; the oxygen concentration detection device 5 is connected with a nitrogen inlet of the kiln body 6 through a nitrogen pipeline.
The length of the kiln body 6 is 60m, and the kiln body 6 sequentially comprises a heating zone 61, a constant temperature zone 62 and a cooling zone 63 from the furnace end to the furnace tail; the length of the heating zone 61 is 20% of the length of the kiln body 6; the length of the constant temperature zone 62 accounts for 44% of the length of the kiln body 6; the length of the cooling area 63 accounts for 36% of the length of the kiln body 6; the first gas outlet 1 is arranged at one end of the constant temperature zone 62 close to the temperature rising zone 61; the first gas outlet 1 is provided with two (not shown); the distance between the two first gas outlets 1 and the temperature rising region 61 is 10% and 15% of the constant temperature region 62.
An inner coating layer is arranged on the inner side of the first air supply device 2; the material of the inner coating is Teflon; the nitrogen pipeline is made of stainless steel pipes; an insulating layer is arranged on the outer side of the nitrogen pipeline; the heat preservation layer is made of aluminum silicate cotton.
The cooling device 3 comprises a coil air cooling device or a coil water cooling device; the device system further comprises a first valve arranged between the oxygen concentration detection device 5 and the nitrogen inlet of the kiln body 6; the device system further comprises a second valve arranged between the first air supply device 2 and the first gas outlet 1; the device system further comprises a first control system for controlling the open/close state of the first valve and/or the second valve according to the oxygen concentration value detected by the oxygen concentration detection device 5.
The device system further comprises a nitrogen gas further exhaust pipeline connected with the oxygen concentration detection device 5.
The device system further comprises a first pressure detector arranged at the first gas outlet 1 and a second pressure detector arranged at the second gas outlet 7; the heating zone 61 of the kiln body 6 is provided with a second gas outlet 7; the second gas outlet 7 is connected with a deodorizing device 9; a second air supply device 8 is arranged between the second air outlet 7 and the deodorizing device 9; the device system further comprises a second control system for controlling the power of the first air supply device 2 and/or the second air supply device 8 according to the pressure values detected by the first pressure detector and the second pressure detector; 37 nitrogen inlets (corresponding to 37 different temperature areas) are arranged at the bottoms of the constant temperature area 62 and the temperature reduction area 63 of the kiln body 6; the temperature raising section 61 is provided with 15 temperature sections.
Example 2
The embodiment provides a roller kiln nitrogen gas reuse's device system, device system includes:
a first gas outlet arranged in the constant temperature area of the kiln body; the first air supply device, the cooling device, the dust removing device and the oxygen concentration detecting device are connected with the first gas outlet through a nitrogen pipeline in sequence; the oxygen concentration detection device is connected with the nitrogen inlet of the kiln body through a nitrogen pipeline.
The length of the kiln body is 60m, and the kiln body sequentially comprises a heating zone, a constant temperature zone and a cooling zone from the furnace end to the furnace tail; the length of the heating area accounts for 27% of the length of the kiln body; the length of the constant temperature zone accounts for 46% of the length of the kiln body; the length of the cooling area accounts for 27% of the length of the kiln body; the first gas outlet is arranged at one end of the constant temperature zone close to the temperature rising zone; the first gas outlet is provided with two (not shown); the distance between the two first gas outlets and the temperature rising area is 7.7% and 10% of the constant temperature area.
An inner coating is arranged on the inner side of the first air supply device; the material of the inner coating is Teflon; the nitrogen pipeline is made of stainless steel pipes; an insulating layer is arranged on the outer side of the nitrogen pipeline; the heat preservation layer is made of aluminum silicate cotton.
The cooling device comprises a coil pipe air cooling device or a coil pipe water cooling device; the device system further comprises a first valve arranged between the oxygen concentration detection device and the nitrogen inlet of the kiln body; the device system further comprises a second valve arranged between the first air supply device and the first gas outlet; the device system further comprises a first control system for controlling the opening and closing states of the first valve and/or the second valve according to the oxygen concentration value detected by the oxygen concentration detection device.
The device system also comprises a nitrogen gas other exhaust pipeline connected with the oxygen concentration detection device.
The device system further includes a first pressure detector disposed at the first gas outlet and a second pressure detector disposed at the second gas outlet; the heating area of the kiln body is provided with a second gas outlet; the second gas outlet is connected with a deodorizing device; a second air supply device is arranged between the second air outlet and the deodorizing device; the device system further comprises a second control system for regulating and controlling any one or at least two of the power of the first air supply device and the second air supply device or the opening degree of a second valve according to the pressure values detected by the first pressure detector and the second pressure detector; 30 nitrogen inlets (corresponding to 30 different temperature areas) are arranged at the bottoms of the constant temperature area and the temperature reduction area of the kiln body; the cooling area is provided with 25 temperature areas.
Example 3
The embodiment provides a roller kiln nitrogen gas reuse's device system, device system includes:
a first gas outlet arranged in the constant temperature area of the kiln body; the first air supply device, the cooling device, the dust removing device and the oxygen concentration detecting device are connected with the first gas outlet through a nitrogen pipeline in sequence; the oxygen concentration detection device is connected with the nitrogen inlet of the kiln body through a nitrogen pipeline.
The length of the kiln body is 80m, and the kiln body sequentially comprises a heating zone, a constant temperature zone and a cooling zone from the furnace end to the furnace tail; the length of the heating area accounts for 18% of the length of the kiln body; the length of the constant temperature zone accounts for 46% of the length of the kiln body; the length of the cooling area accounts for 36% of the length of the kiln body; the first gas outlet is arranged at one end of the constant temperature zone close to the temperature rising zone; the first gas outlet is provided with two (not shown); the distance between the two first gas outlets and the temperature rising area is 15% and 20% of the constant temperature area.
An inner coating is arranged on the inner side of the first air supply device; the material of the inner coating is Teflon; the nitrogen pipeline is made of stainless steel pipes; an insulating layer is arranged on the outer side of the nitrogen pipeline; the heat preservation layer is made of aluminum silicate cotton.
The cooling device comprises a coil pipe air cooling device or a coil pipe water cooling device; the device system further comprises a first valve arranged between the oxygen concentration detection device and the nitrogen inlet of the kiln body; the device system further comprises a second valve arranged between the first air supply device and the first gas outlet; the device system further comprises a first control system for controlling the opening and closing states of the first valve and/or the second valve according to the oxygen concentration value detected by the oxygen concentration detection device.
The device system also comprises a nitrogen gas other exhaust pipeline connected with the oxygen concentration detection device.
The device system further includes a first pressure detector disposed at the first gas outlet and a second pressure detector disposed at the second gas outlet; the heating area of the kiln body is provided with a second gas outlet; the second gas outlet is connected with a deodorizing device; a second air supply device is arranged between the second air outlet and the deodorizing device; the device system further comprises a second control system for regulating and controlling any one or at least two of the power of the first air supply device and the second air supply device or the opening degree of a second valve according to the pressure values detected by the first pressure detector and the second pressure detector; 42 nitrogen inlets (corresponding to 42 different temperature areas) are arranged at the bottoms of the constant temperature area and the temperature reduction area of the kiln body; the cooling area is provided with 18 temperature areas.
Example 4
The embodiment provides a device system for recycling nitrogen in a roller kiln, which is the same as that in embodiment 1 except that the distances between two first gas outlets and the heating area are 5% and 15% of the constant temperature area.
Example 5
The embodiment provides a device system for recycling nitrogen in a roller kiln, which is the same as that in embodiment 1 except that only one first gas outlet is arranged, and the distance between the first gas outlet and the temperature rising area is 25% of that between the first gas outlet and the temperature rising area.
Example 6
The embodiment provides a device system for recycling nitrogen in a roller kiln, which is the same as that in embodiment 1 except that only one first gas outlet is arranged, namely, the distance between the first gas outlet and the temperature rising area is 10% of that between the first gas outlet and the temperature rising area.
Application example 1
The application example provides a method for recycling nitrogen of a roller kiln, the method is carried out by adopting the device system for recycling nitrogen of the roller kiln provided by the embodiment 1, and the method comprises the following steps:
nitrogen is introduced into the constant temperature area and the cooling area of the kiln body; the first air supply device extracts gas to be recovered from a first gas outlet, the gas to be recovered is cooled to less than or equal to 200 ℃ through the cooling device in sequence and is dedusted through the dedusting device to obtain recovered nitrogen, the recovered nitrogen is circularly sent into a constant temperature area and a cooling area of the kiln body after the oxygen concentration detection device detects that the oxygen concentration is less than or equal to 50ppm, and when the oxygen concentration of the recovered nitrogen is less than or equal to 50ppm through the oxygen concentration detection device, the first control system firstly closes a first valve, then closes a second valve, and discharges the nitrogen in a nitrogen pipeline through another nitrogen pipeline;
the second air supply device extracts the gas to be deodorized from the second gas outlet and sends the gas to the deodorization device for deodorization treatment; the wind pressure of the first gas outlet is smaller than that of the second gas outlet; the wind pressure of the first gas outlet is 8Pa smaller than that of the second gas outlet; and when the difference between the wind pressure of the first gas outlet and the wind pressure of the second gas outlet is not in the set range, the second control system adjusts any one or the combination of at least two of the power of the second air supply device, the power of the first air supply device and the opening of the second valve.
The system in application example 1 can stably and safely run, the purity of the nitrogen extracted from the first gas outlet is high, the oxygen content after cooling and dust removal can reach the standard less than or equal to 50ppm, the recycling rate of the nitrogen in the constant temperature area and the cooling area is up to 90%, and the annual nitrogen can be saved by 310 ten thousand m for equipment producing 4500 tons of anode material per year 3 The annual saving cost is up to 651 ten thousand yuan, the economic benefit is obvious, and the emission of nitrogen entering the deodorizing furnace is reduced.
Application examples 2 to 6
Application examples 2-6 respectively provide a method for recycling nitrogen in a roller kiln, and the method is the same as application example 1 except that the device system for recycling nitrogen in the roller kiln provided in the embodiment examples 2-6 is adopted.
In application examples 2 and 3, similar technical effects to those in application example 1 can be obtained, and as shown in table 1, it can be seen that the total application examples 1 to 3 can save the cost by 615 ten thousand yuan or more for equipment producing 4500 tons of positive electrode material per year.
As can be seen from comparison of application examples 4-5 and application example 1, the arrangement position of the first gas outlet is very critical, wherein in application example 4, the first gas outlet is arranged at a position which is only 5% away from the temperature raising region, so that during operation, the control of the operation parameters is difficult, and the gas in the temperature lowering region is easy to appearThe fact that the first gas outlet is drawn in eventually results in an increase in the operating costs of nitrogen recovery, which is only about 525 ten thousand yuan for a device producing 4500 tons of positive electrode material annually. In application example 5, the first gas outlet is arranged at the middle position of the constant temperature zone, so that the loss of nitrogen in the front section of the constant temperature zone is serious, the utilization rate of nitrogen is only 73%, and the annual nitrogen-saving amount is only 251 ten thousand m 3 The annual saving cost is 527.1 ten thousand yuan finally, so that the invention shows that the cost can be better saved and the nitrogen recycling rate can be improved by arranging the position of the first gas outlet at a proper position.
As can be seen from comparison of application examples 6 and 1, in application example 1, two first gas outlets are provided, and compared with application example 6 in which only one first gas outlet is provided, the annual cost saving in application example 1 is up to 651 ten thousand yuan, while in application example 6, because the pressure in the roller kiln and the wind pressure control of the first gas outlet and the second gas outlet are difficult, the running cost of the device system is increased, the condition that the second valve is closed frequently occurs, the overall recovery rate of nitrogen is reduced to 78%, and the annual cost saving cost is only 564 ten thousand yuan, so that the invention is favorable for improving the overall nitrogen recovery rate by preferably arranging at least two first gas outlets.
Application example 7
The application example provides a method for recycling nitrogen of a roller kiln, which is the same as application example 1 except that the wind pressure of a first gas outlet is smaller than that of a second gas outlet by 0.2 Pa.
Application example 8
The application example provides a method for recycling nitrogen of a roller kiln, which is the same as application example 1 except that the wind pressure of a first gas outlet is smaller than that of a second gas outlet by 120 Pa.
As can be seen from comparison of application examples 1 and 7-8, the wind pressure of the first gas outlet in application example 7 is only 0.2Pa smaller than the wind pressure of the second gas outlet, so that the gas in the temperature raising region is easily pumped into the first gas outlet due to the condition of easy pressure deviation in the operation process, the purity of nitrogen recovery is reduced, good recycling is difficult, and the system is difficult to continuously and safely operate; in application example 8, since the wind pressure of the first gas outlet is much smaller than the wind pressure of the second gas outlet, it is difficult to extract enough nitrogen from the first gas outlet, and the recycling rate of the nitrogen is only 10%, which indicates that the present invention preferably controls the difference between the wind pressure of the first gas outlet and the wind pressure of the second gas outlet during operation, which is more favorable for smooth operation of the device system and improvement of the recycling rate of the nitrogen.
Application example 9
The application example provides a method for recycling nitrogen in a roller kiln, which is the same as that of application example 1 except that when the recovered nitrogen is detected by an oxygen concentration detection device to not reach the standard range of 50ppm or less, a first control system firstly closes a second valve and then closes a first valve.
Application example 1 closes first valve when handling the condition that oxygen concentration exceeds standard earlier, and application example 1 can protect the product of the anodal material production in the roller kiln to receive the influence better, the furthest reduces the loss compared with application example 8 closes the second valve when handling emergency earlier.
Comparative example 1
This comparative example provides a device system of a roller kiln, as shown in fig. 2, which is the same as that of example 1 except that the first gas outlet 1, the first air supply device 2, the cooling device 3, the dust removing device 4, and the oxygen concentration detecting device 5 and their related connections are not provided.
Specifically, the device system comprises a kiln body 6, wherein the length of the kiln body 6 is 60m, and the kiln body 6 sequentially comprises a heating zone 61, a constant temperature zone 62 and a cooling zone 63 from a furnace end to a furnace tail; the length of the heating zone 61 is 20% of the length of the kiln body 6; the length of the constant temperature zone 62 is 44% of the length of the kiln body 6, and the length of the cooling zone 63 is 36% of the length of the kiln body 6.
The device system further comprises a second pressure detector arranged at the second gas outlet 7; the heating zone 61 of the kiln body 6 is provided with a second gas outlet 7; the second gas outlet 7 is connected with a deodorizing device 9; a second air supply device 8 is arranged between the second air outlet 7 and the deodorizing device 9; 37 nitrogen inlets (corresponding to 37 different temperature areas) are arranged at the bottoms of the constant temperature area 62 and the temperature reduction area 63 of the kiln body 6; the temperature raising section 61 is provided with 15 temperature sections.
The comparative example is not provided with a first gas outlet, a first air supply device, a cooling device and a dust removing device, nitrogen in the constant temperature area and the cooling area cannot be recycled, and the overall cost is high.
The nitrogen recycling rate is recorded by dividing the flow of the circulated and returned nitrogen by the flow of the nitrogen which totally enters the constant temperature area and the temperature reduction area in the kiln body, the nitrogen saving amount of 4500 tons of anode material produced in one year is counted, the operation cost of the nitrogen recycling is subtracted according to the sum of the nitrogen production energy consumption and the operation management cost of the self-produced nitrogen, the saved nitrogen cost is calculated according to the unit price of 2.1 yuan per cubic meter, and the results of application examples 1-3 are shown in table 1.
TABLE 1
The applicant declares that the above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be apparent to those skilled in the art that any changes or substitutions that are easily conceivable within the technical scope of the present invention disclosed by the present invention fall within the scope of the present invention and the disclosure.
Claims (8)
1. The utility model provides a roller kiln nitrogen gas reuse's device system which characterized in that, device system includes:
a first gas outlet arranged in the constant temperature area of the kiln body;
the first air supply device, the cooling device, the dust removing device and the oxygen concentration detecting device are connected with the first gas outlet through a nitrogen pipeline in sequence;
the oxygen concentration detection device is connected with a nitrogen inlet of the kiln body through a nitrogen pipeline;
the first gas outlet is arranged at one end of the constant temperature zone close to the temperature rising zone;
the distance between the first gas outlet and the temperature rising area is 7.7-23% of the constant temperature area;
the heating area of the kiln body is provided with a second gas outlet;
the second gas outlet is connected with a deodorizing device;
the wind pressure of the first gas outlet is smaller than that of the second gas outlet;
the wind pressure of the first gas outlet is 5-70 Pa smaller than that of the second gas outlet;
the kiln body sequentially comprises a heating area, a constant temperature area and a cooling area from the furnace end to the furnace tail.
2. The plant system according to claim 1, further comprising a first valve disposed between the oxygen concentration detection device and the nitrogen inlet of the kiln body;
the device system further comprises a second valve arranged between the first air supply device and the first gas outlet;
the device system further comprises a first control system for controlling the opening and closing states of the first valve and/or the second valve according to the oxygen concentration value detected by the oxygen concentration detection device.
3. The device system of claim 2, wherein the device system comprises a plurality of devices,
a second air supply device is arranged between the second air outlet and the deodorizing device;
the device system further includes a first pressure detector disposed at the first gas outlet and a second pressure detector disposed at the second gas outlet;
the device system further comprises a second control system for regulating and controlling any one or at least two of the power of the first air supply device, the power of the second air supply device or the opening degree of the second valve according to the pressure values detected by the first pressure detector and the second pressure detector.
4. A method for recycling nitrogen in a roller kiln, which is characterized by adopting the device system for recycling nitrogen in the roller kiln according to any one of claims 1-3.
5. The method according to claim 4, characterized in that the method comprises: nitrogen is introduced into the constant temperature area and the cooling area of the kiln body; the first air supply device extracts gas to be recovered from the first gas outlet, the gas to be recovered is cooled by the cooling device and is dedusted by the dedusting device in sequence to obtain recovered nitrogen, and the recovered nitrogen is circularly fed into the constant temperature area and the cooling area of the kiln body after the oxygen concentration of the recovered nitrogen reaches the standard range through the oxygen concentration detection device.
6. The method according to claim 5, wherein the first control system closes the first valve and the second valve and discharges the nitrogen gas in the nitrogen gas pipe through the nitrogen gas additional pipe when the oxygen concentration detected by the oxygen concentration detecting means does not reach the standard range.
7. The method of claim 5 or 6, wherein the second control system monitors that the difference between the wind pressure at the first gas outlet and the wind pressure at the second gas outlet is not within a set range, and adjusts any one or a combination of at least two of the power of the second air-moving device, the power of the first air-moving device, or the opening of the second valve.
8. The method according to claim 5, characterized in that the method comprises:
nitrogen is introduced into the constant temperature area and the cooling area of the kiln body; the first air supply device extracts gas to be recovered from a first gas outlet, the gas to be recovered is cooled to less than or equal to 200 ℃ through the cooling device in sequence and is dedusted through the dedusting device to obtain recovered nitrogen, the recovered nitrogen is circularly sent into a constant temperature area and a cooling area of the kiln body after the oxygen concentration detection device detects that the oxygen concentration is less than or equal to 50ppm, and when the oxygen concentration of the recovered nitrogen is less than or equal to 50ppm through the oxygen concentration detection device, the first control system firstly closes a first valve, then closes a second valve, and discharges the nitrogen in a nitrogen pipeline through another nitrogen pipeline;
the second air supply device extracts the gas to be deodorized from the second gas outlet and sends the gas to the deodorization device for deodorization treatment; the wind pressure of the first gas outlet is smaller than that of the second gas outlet; the wind pressure of the first gas outlet is 5-15 Pa smaller than that of the second gas outlet; and when the difference between the wind pressure of the first gas outlet and the wind pressure of the second gas outlet is not in the set range, the second control system adjusts any one or a combination of at least two of the power of the second air supply device, the power of the first air supply device and the opening of the second valve.
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| CN210718620U (en) * | 2019-07-26 | 2020-06-09 | 广东中鹏新能科技有限公司 | Atmosphere protection roller kiln |
| CN216592724U (en) * | 2021-11-12 | 2022-05-24 | 佛山市天禄智能装备科技有限公司 | Lithium cell cathode material carbonization production roller kilns |
| CN115307425A (en) * | 2022-07-28 | 2022-11-08 | 湖南烁科热工智能装备有限公司 | Novel gas roller kiln for sintering lithium battery material |
| CN218097173U (en) * | 2022-09-08 | 2022-12-20 | 苏州田边热能科技有限公司 | Nitrogen preheating system for reducing energy consumption of firing furnace in lithium battery industry |
| CN115615212A (en) * | 2022-11-05 | 2023-01-17 | 佛山保嘉源环境工程技术有限公司 | Be applied to heat radiation heating device of kiln |
| CN115682742A (en) * | 2022-12-16 | 2023-02-03 | 佛山保嘉源环境工程技术有限公司 | Temperature gradient controlled nitrogen heat-conducting medium atmosphere kiln |
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