Dolomite calcining system using hydrogen energy as fuel

Abstract

The utility model provides a dolomite calcining system using hydrogen energy as fuel, which comprises a rotary kiln used for calcining dolomite, a hydrogen burner and a tail gas condensation recovery device, the hydrogen burner is arranged on a burning port of the rotary kiln and used for calcining the dolomite in the rotary kiln, and the tail gas condensation recovery device is arranged on the rotary kiln. A tail gas outlet of the rotary kiln is connected with an inlet of the tail gas condensation recovery device, high-temperature tail gas discharged by the rotary kiln enters the tail gas condensation recovery device, the tail gas condensation recovery device recovers moisture and dust in the tail gas discharged by the rotary kiln, the recovered moisture is recycled, water resources are saved, only water is generated after hydrogen is burnt, and energy is saved. No harmful substance is generated, emission of harmful substances and carbon dioxide is greatly reduced, environmental protection is facilitated, and the requirement of the current society for environmental protection is met.

Description

Technical Field

[0001] The utility model relates to the technical field of dolomite calcination, and particularly relates to a dolomite calcination system fueled by hydrogen energy. Background Art

[0002] Dolomite calcination is an important link in the metal magnesium smelting process. Dolomite calcination is mainly carried out through a rotary kiln. At present, the dolomite calcination rotary kilns applied in China generally still use water coal slurry or pulverized coal as fuel. The combustion temperature of water coal slurry and pulverized coal is difficult to accurately control, resulting in unstable calcined white quality. Moreover, a large amount of harmful substances will be released after the combustion of water coal slurry and pulverized coal, such as carbon monoxide, carbon dioxide, sulfur dioxide, soot, radioactive floating dust, nitrogen oxides, etc. Their emissions cause great pressure on the environment. Moreover, a large amount of wastewater and waste residues will be generated when dealing with these harmful substances. These harmful substances, wastewater and waste residues will seriously pollute the environment, not only pose a direct threat to human health, waste water resources, but also cause problems such as acid rain and greenhouse effect. Content of the Utility Model

[0003] In view of this, it is necessary to provide a dolomite calcination system fueled by hydrogen energy to solve the technical problems of environmental pollution and water resource waste existing in the prior art.

[0004] The technical solution adopted by the utility model to solve its technical problems is as follows:

[0005] A dolomite calcination system fueled by hydrogen energy includes a rotary kiln for calcining dolomite, a hydrogen burner and a tail gas condensation and recovery device. The hydrogen burner is arranged at the combustion port of the rotary kiln and is used for calcining the dolomite in the rotary kiln. The tail gas outlet of the rotary kiln is connected to the inlet of the tail gas condensation and recovery device. The high-temperature tail gas discharged from the rotary kiln enters the tail gas condensation and recovery device. The tail gas condensation and recovery device recovers the moisture and dust in the tail gas discharged from the rotary kiln and circulates the recovered moisture for use.

[0006] Preferably, the tail gas condensation and recovery device includes a tail gas cooling tower, a clarification tank and a circulation pump. The tail gas outlet of the rotary kiln is connected to the inlet of the tail gas cooling tower. The clarification tank is arranged below the tail gas cooling tower. The outlet of the tail gas cooling tower faces the clarification tank. A sprayer is arranged at the top inside the tail gas cooling tower. The input end of the circulation pump is connected to the clean water outlet of the clarification tank, and the output end of the circulation pump is connected to the sprayer to transport the clean water in the clarification tank to the sprayer, and the sprayer is used to spray and condense the tail gas discharged from the rotary kiln, so that the dust and the condensed moisture in the tail gas discharged from the rotary kiln enter the clarification tank for precipitation.

[0007] Preferably, the clarifier includes a primary clarifier and a secondary clarifier. The primary clarifier is arranged directly below the tail gas cooling tower to receive the water and dust recovered from the tail gas of the sprayer. The secondary clarifier is arranged in parallel with the primary clarifier. The purified water outlet of the primary clarifier is connected to the water inlet of the secondary clarifier. The input end of the circulation pump is connected to the purified water outlet of the secondary clarifier. The water and dust recovered from the tail gas flow into the secondary clarifier for secondary sedimentation after being sedimented in the primary clarifier. The purified water after secondary sedimentation in the secondary clarifier is transported to the sprayer through the circulation pump for circulating spraying.

[0008] Preferably, sewage outlets are provided at the bottoms of both the primary clarifier and the secondary clarifier.

[0009] Preferably, a heat pipe type air preheater is further arranged between the rotary kiln and the tail gas condensation recovery device. The tail gas outlet of the rotary kiln is connected to the tail gas inlet of the heat pipe type air preheater. The tail gas outlet of the heat pipe type air preheater is connected to the inlet of the tail gas condensation recovery device. The air heat exchange port of the heat pipe type air preheater is connected to the air inlet of the hydrogen burner. The heat pipe type air preheater uses the high-temperature tail gas discharged from the rotary kiln to preheat the air entering the hydrogen burner to assist the combustion of hydrogen, and conducts the heat-exchanged tail gas into the tail gas condensation recovery device to recover the water in the tail gas by the tail gas condensation recovery device.

[0010] Preferably, a blower is arranged at the air heat exchange port of the heat pipe type air preheater or the air inlet of the hydrogen burner to send air into the hydrogen burner.

[0011] As can be seen from the above technical solutions, the dolomite calcination system provided by the present application using hydrogen energy as fuel includes a rotary kiln for calcining dolomite, a hydrogen burner and a tail gas condensation recovery device. The hydrogen burner is arranged at the combustion port of the rotary kiln for calcining the dolomite in the rotary kiln. The tail gas outlet of the rotary kiln is connected to the inlet of the tail gas condensation recovery device. The high-temperature tail gas discharged from the rotary kiln enters the tail gas condensation recovery device. The tail gas condensation recovery device recovers the water and dust in the tail gas discharged from the rotary kiln and circulates the recovered water, saving water resources. After hydrogen combustion, only water is produced and no harmful substances are generated, greatly reducing the emission of harmful substances and carbon dioxide, being beneficial to environmental protection and meeting the current social requirements for environmental protection. Moreover, the combustion temperature of hydrogen energy is easy to control, being beneficial to improving the quality and output of dolomite calcination, and having great technical application value for the metal magnesium smelting industry. Description of the Drawings

[0012] Figure 1 Schematic diagram of the dolomite calcination system using hydrogen energy as fuel disclosed in the embodiment of the present application

[0013] In the figure: rotary kiln 10, hydrogen burner 20, hydrogen energy storage tank 201, tail gas condensation and recovery device 30, tail gas cooling tower 301, circulation pump 302, primary clarifier 303, secondary clarifier 304, sprayer 305, sewage outlet 306, heat dissipation pipe 40, heat pipe type air preheater 50, fan 60. Detailed implementation manners

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0015] Please refer to Figure 1 , the embodiment of the present invention provides a dolomite calcination system using hydrogen energy as fuel, including a rotary kiln 10 for calcining dolomite, a hydrogen burner 20 and a tail gas condensation and recovery device 30. The hydrogen burner 20 is arranged at the combustion port of the rotary kiln 10 and is used for calcining the dolomite in the rotary kiln 10. The hydrogen burner 20 provides hydrogen by connecting to a hydrogen energy storage tank 201 arranged externally. The tail gas outlet of the rotary kiln 10 is connected to the inlet of the tail gas condensation and recovery device 30. The high-temperature tail gas after hydrogen combustion enters the tail gas condensation and recovery device 30 through the tail gas outlet of the rotary kiln 10. The water and dust in the tail gas discharged from the rotary kiln 10 are recovered through the tail gas condensation and recovery device 30, and the recovered water is recycled. As a clean energy, hydrogen only produces water after combustion and does not produce any harmful substances, and will not cause environmental pollution after combustion, meeting the requirements of environmental protection and emission reduction. Moreover, by recovering the water generated during hydrogen combustion, it can be reused to save water resources.

[0016] Specifically, the tail gas condensation recovery device 30 includes a tail gas cooling tower 301, a clarification tank, and a circulation pump 302. The tail gas outlet of the rotary kiln 10 is connected to the inlet of the tail gas cooling tower 301 through a heat dissipation pipe 40. The clarification tank is arranged below the tail gas cooling tower 301, and the outlet of the tail gas cooling tower 301 faces the clarification tank. A sprayer 305 is arranged at the top inside the tail gas cooling tower 301. The input end of the circulation pump 302 is connected to an external water supply pipe and the clean water outlet of the clarification tank, and the output end of the circulation pump 302 is connected to the sprayer 305. The hydrogen burner 20 is arranged at the combustion port of the rotary kiln 10. The high-temperature tail gas after hydrogen combustion is discharged from the tail gas outlet of the rotary kiln 10 and then enters the heat dissipation pipe 40. After the high-temperature tail gas is cooled by the heat dissipation pipe 40, it is introduced into the tail gas cooling tower 301. The tail gas after hydrogen combustion is cooled and condensed by the sprayer 305. The water generated after the tail gas condensation enters the clarification tank for precipitation. The clarified water after precipitation is then transported to the sprayer 305 by the circulation pump 302 for recycling. Moreover, during the spraying process, the dust generated by the calcination of dolomite contained in the tail gas will also enter the clarification tank along with the spraying water under the action of spraying, playing a role in dust removal.

[0017] In order to enable the clarification tank to effectively precipitate and separate the condensate and dust precipitates, the clarification tank is set as a primary clarification tank 303 and a secondary clarification tank 304. The primary clarification tank 303 is arranged directly below the tail gas cooling tower 301 to receive the condensate and dust precipitates. The secondary clarification tank 304 is arranged in parallel with the primary clarification tank 303. The clean water outlet of the primary clarification tank 303 is connected to the water inlet of the secondary clarification tank 304. The input end of the circulation pump 302 is connected to the clean water outlet of the secondary clarification tank 304. After the water and dust recovered from the tail gas are precipitated in the primary clarification tank 303, the clean water flows into the secondary clarification tank 304 for secondary precipitation. The clean water after secondary precipitation in the secondary clarification tank 304 is then transported to the sprayer 305 by the circulation pump 302 for circulating spraying.

[0018] Furthermore, sewage outlets 306 are arranged at the bottoms of both the primary clarification tank 303 and the secondary clarification tank 304. The sewage outlets 306 are in a normally closed state. During the long-term operation of the system, the dust and impurities generated by the calcination of dolomite will precipitate at the bottoms of the primary clarification tank 303 and the secondary clarification tank 304. The arrangement of the sewage outlets 306 facilitates the cleaning of the primary clarification tank 303 and the secondary clarification tank 304.

[0019] It should be noted that the external water supply pipe is connected to the water purification port of the secondary clarifier 304 through a three-way valve and the input end of the circulation pump 302. When the dolomite calcination system is in the initial startup stage or the water in the clarifier is insufficient, the three-way valve can be switched to supply water to the sprayer 305 through the external water supply pipe. When the water collected in the clarifier is sufficient, the three-way valve can be switched to directly transport the water in the clarifier to the sprayer 305 through the circulation pump 302 for circulating spraying.

[0020] Please continue to refer to Figure 1 Furthermore, a heat pipe type air preheater 50 is also provided between the rotary kiln 10 and the tail gas condensation recovery device 30. The tail gas outlet of the rotary kiln 10 is connected to the tail gas inlet of the heat pipe type air preheater 50. The tail gas outlet of the heat pipe type air preheater 50 is connected to the inlet of the tail gas condensation recovery device 30 through the heat dissipation pipe 40. The air heat exchange port of the heat pipe type air preheater 50 is connected to the air inlet of the hydrogen burner 20, and a blower 60 is provided at the air heat exchange port of the heat pipe type air preheater 50 or the air inlet of the hydrogen burner 20. The heat pipe type air preheater 50 preheats the air entering the hydrogen burner 20 with the high-temperature tail gas discharged from the rotary kiln 10, and uses the blower 60 to send the preheated air to the hydrogen burner 20 to assist in the combustion of hydrogen, and conducts the heat-exchanged tail gas into the tail gas condensation recovery device 30 through the heat dissipation pipe 40 to recover the moisture in the tail gas by the tail gas condensation recovery device 30. The heat pipe type air preheater 50 is an air heat exchange device that uses heat pipe technology to recover the heat in the high-temperature tail gas discharged from the rotary kiln 10 and is used to preheat the air entering the hydrogen burner 20 to assist in the combustion of hydrogen. The tail gas discharged from the rotary kiln 10 is the high-temperature tail gas generated after the hydrogen burner 20 burns hydrogen in the rotary kiln 10, and the high-temperature tail gas will contain a large amount of moisture. The high-temperature tail gas is cooled by heat exchange in the heat pipe type air preheater 50 and then introduced into the tail gas cooling tower 301 through the heat dissipation pipe 40. After the high-temperature tail gas is cooled by heat exchange in the heat pipe type air preheater 50 and the heat dissipation pipe 40, the temperature of the tail gas can be effectively reduced, which is beneficial for the tail gas cooling tower 301 to condense and recover the moisture in the tail gas. Preheating the air entering the hydrogen burner 20 with the high-temperature tail gas discharged from the rotary kiln 10 to assist in the combustion of hydrogen has the effect of energy saving and effectively reduces the energy consumption output.

[0021] The above-disclosed are only the preferred embodiments of the present invention. Of course, the scope of the rights of the present invention cannot be limited by this. Those of ordinary skill in the art can understand the entire or partial processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A dolomite calcining system using hydrogen energy as fuel, characterized in that: The invention comprises a rotary kiln for calcining dolomite, a hydrogen burner and a tail gas condensation recovery device. The hydrogen burner is arranged on the combustion port of the rotary kiln and is used to calcine the dolomite in the rotary kiln. The tail gas outlet of the rotary kiln is connected with the inlet of the tail gas condensation recovery device. The high-temperature tail gas discharged from the rotary kiln enters the tail gas condensation recovery device. The tail gas condensation recovery device recovers moisture and dust in the tail gas discharged from the rotary kiln and recycles the recovered moisture.

2. The dolomite calcining system using hydrogen as fuel as claimed in claim 1, characterized in that: The tail gas condensation recovery device comprises a tail gas cooling tower, a clarifier, and a circulation pump. The tail gas outlet of the rotary kiln is connected to the inlet of the tail gas cooling tower. The clarifier is arranged below the tail gas cooling tower. The outlet of the tail gas cooling tower faces the clarifier. A sprayer is arranged on the top of the tail gas cooling tower. The input end of the circulation pump is connected to the clean water outlet of the clarifier. The output end of the circulation pump is connected to the sprayer to transport the clean water in the clarifier to the sprayer. The sprayer is used to spray and condense the tail gas discharged from the rotary kiln, so that the dust and condensed water in the tail gas discharged from the rotary kiln enter the clarifier for precipitation.

3. The dolomite calcining system using hydrogen as fuel as claimed in claim 2, characterized in that: The clarifier includes a primary clarifier and a secondary clarifier. The primary clarifier is arranged directly below the tail gas cooling tower to receive moisture and dust recovered from the tail gas of the sprayer. The secondary clarifier and the primary clarifier are arranged in parallel. The clean water outlet of the primary clarifier is connected to the water inlet of the secondary clarifier. The input end of the circulation pump is connected to the clean water outlet of the secondary clarifier. The water recovered from the tail gas and the dust are precipitated in the primary clarifier and flow into the secondary clarifier for secondary precipitation. The clean water after secondary precipitation in the secondary clarifier is transported to the sprayer through the circulation pump for circulating spraying.

4. The dolomite calcining system using hydrogen as fuel as claimed in claim 3, characterized in that: The bottoms of the primary clarification tank and the secondary clarification tank are both provided with sewage outlets.

5. The dolomite calcining system using hydrogen as fuel as claimed in claim 4, characterized in that: A heat pipe air preheater is also arranged between the rotary kiln and the tail gas condensation recovery device. The tail gas outlet of the rotary kiln is connected to the tail gas inlet of the heat pipe air preheater, the tail gas outlet of the heat pipe air preheater is connected to the inlet of the tail gas condensation recovery device, and the air heat exchange port of the heat pipe air preheater is connected to the air inlet of the hydrogen burner. The heat pipe air preheater uses the high-temperature tail gas discharged from the rotary kiln to preheat the air entering the hydrogen burner to assist hydrogen combustion, and introduces the tail gas after heat exchange into the tail gas condensation recovery device, and uses the tail gas condensation recovery device to recover moisture in the tail gas.

6. The dolomite calcining system using hydrogen as fuel as claimed in claim 5, characterized in that: A fan is provided on the air heat exchange port of the heat pipe air preheater or the air inlet of the hydrogen burner, and air is supplied to the hydrogen burner through the fan.

Images