Novel lime production system adopting preheating bin and electric heating rotary kiln

Abstract

The utility model discloses a novel lime production system adopting a preheating bin and an electric heating rotary kiln, which comprises the rotary kiln, a hopper, a conveyor, a belt weigher and a buffer bin, a vertical cooler and a carbon dioxide gas collecting cavity are respectively arranged at two ends of the rotary kiln, the rotary kiln adopts electromagnetic heating, and the conveyor is arranged in the buffer bin. The temporary storage bin is communicated with the rotary kiln through a preheating bin and a kiln inlet chute; a snakelike heat exchange pipe is arranged in the preheating bin, an inlet of the snakelike heat exchange pipe is communicated with an outlet of the carbon dioxide collecting cavity, and an outlet of the snakelike heat exchange pipe is communicated with a second bag type dust collector; an inlet in the lower end of one side of the wall of the preheating bin body is communicated with an outlet of the vertical cooler, and an outlet in the upper end of the other side of the wall of the preheating bin body is communicated with a first bag type dust collector. According to the utility model, the energy consumption can be reduced, the produced lime has better quality, air combustion is not needed in the production process, waste gas pollution is not generated, desulfurization and denitrification are not needed, and the flue gas treatment cost can be reduced.

Description

Technical Field

[0001] The utility model relates to a lime production system, in particular to a new lime production system which adopts a preheating bin and an electric heating rotary kiln. Background Art

[0002] The existing technology uses natural gas or biomass instead of coal as fuel to produce lime. Natural gas is expensive and the production cost is too high. Direct calcination of biomass pollutes the finished lime product. The technology of gasifying biomass fuel for lime production is not yet mature.

[0003] The existing technology uses the method of calcining limestone powder to improve the calcination efficiency by making the hot gas fully contact with the powder, thereby achieving energy saving effect. However, incomplete combustion of fuel is an objective reality, and the pollution problem caused by the fuel cannot be solved.

[0004] The existing technology uses limestone decomposition to produce a large amount of carbon dioxide that is directly discharged into the atmosphere, exacerbating the greenhouse effect and going against the concept of carbon reduction. Utility Model Content

[0005] The technical problem to be solved by the utility model is to overcome the shortcomings of the prior art and provide a new lime production system using a preheating bin and an electrically heated rotary kiln, which has a reasonable design, high waste heat utilization rate, reduced flue gas treatment cost and reduced energy consumption.

[0006] The technical solution of the utility model is:

[0007] A new lime production system using a preheating bin and an electrically heated rotary kiln, comprising a rotary kiln, a hopper, a conveyor, a belt scale and a buffer bin. The discharge end and the feed end of the rotary kiln are respectively provided with a vertical cooler and a carbon dioxide collecting chamber. An electromagnetic heater is provided on the outer wall of the rotary kiln to achieve electromagnetic heating.

[0008] The discharge port of the hopper is connected to the feed port of the buffer bin through the belt scale and the conveyor, the discharge port of the buffer bin is connected to the feed port of the preheating bin through a control valve, and the discharge port of the preheating bin is connected to the feed end of the rotary kiln through another control valve and the kiln chute;

[0009] A serpentine heat exchange tube is arranged in the preheating chamber, the inlet of the serpentine heat exchange tube is connected with the outlet of the carbon dioxide collecting chamber, and the outlet of the serpentine heat exchange tube is connected with the second bag dust collector;

[0010] The inlet at the lower end of one side of the preheating bin wall is communicated with the outlet of the vertical cooler, and the outlet at the upper end of the other side of the preheating bin wall is communicated with the first bag dust collector.

[0011] Furthermore: the control valve includes a spiral gate valve and a double-layer air lock valve, which are connected in series, and the spiral gate valve is connected to the lower end of the bin body.

[0012] Furthermore: the first bag dust collector and the second bag dust collector are respectively connected to the air compressor, and are respectively provided with a regulating valve.

[0013] Furthermore: the outlet of the second bag filter is connected to a carbon dioxide gas storage tank, and the carbon dioxide in the carbon dioxide gas storage tank can be used to make dry ice or directly exported.

[0014] Furthermore: the conveyor is an inclined conveyor, a fan is provided on the vertical cooler, and the outlet of the first bag dust collector is emptied.

[0015] The beneficial effects of the utility model are:

[0016] 1. The utility model can reduce energy consumption. At the same time, the lime produced has better quality and does not require air combustion during the production process, will not generate waste gas pollution, does not require desulfurization and denitrification, and can reduce the cost of flue gas treatment.

[0017] 2. The utility model has two heat sources for the preheating bin. One is the hot air after heat exchange with lime in the vertical cooler, which is directly heated by passing into the preheating bin through a pipeline; the other is the ultra-high purity carbon dioxide produced by the calcination and decomposition of limestone in the rotary kiln, which indirectly preheats the limestone through the coil in the bin, making full use of the waste heat.

[0018] 3. The rotary kiln cylinder of the utility model is made of S30815 stainless steel, and the calcination temperature is not higher than 1000℃. A 3-5cm ceramic fiber cotton insulation layer is set outside the cylinder, and the temperature is reduced from 1000℃ to below 100℃. The electromagnetic heating coil is outside the insulation layer, and eddy currents are generated on the cylinder through electromagnetic induction to directly heat the cylinder. The use of electromagnetic indirect heating to calcine lime in the rotary kiln does not pollute the product and is suitable for producing high-quality lime.

[0019] 4. The utility model has fast electromagnetic heating speed, high thermal efficiency, energy saving, simple and easy temperature control, few human interference factors, stable finished product quality, no air involved in combustion, no combustion exhaust gas generated, so no desulfurization and denitrification are required, which meets environmental protection requirements and reduces processing costs.

[0020] 5. The concentration of carbon dioxide produced by the decomposition of limestone inside the rotary kiln cylinder of the utility model is extremely high, which can be fully utilized after being collected to make dry ice or exported, thus truly achieving zero carbon emissions.

[0021] 6. The utility model has reasonable design, high waste heat utilization rate, reduced flue gas treatment cost and energy consumption, is easy to promote and implement, and has good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a new lime production system using a preheating bin and an electrically heated rotary kiln;

[0023] Figure 2 for Figure 1 Enlarged view of the preheating device. DETAILED DESCRIPTION

[0024] Example: See Figure 1 -- Figure 2 In the figure, 1- conveyor, 2- belt scale, 3- hopper, 4- first bag dust collector, 5- air compressor, 6- second bag dust collector, 7- carbon dioxide gas storage cabinet, 8- preheating device, 9- rotary kiln, 10- vertical cooler, 11- fan, 12- carbon dioxide gas collecting chamber, 13- cache bin, 14- spiral plug valve, 15- double-layer air lock valve, 16- serpentine heat exchange tube, 17- preheating bin.

[0025] A novel lime production system using a preheating bin and an electrically heated rotary kiln comprises a rotary kiln 9, a hopper 3, a conveyor 1, a belt scale 2 and a buffer bin 13, wherein: a vertical cooler 10 and a carbon dioxide gas collecting chamber 12 are respectively provided at the discharge end and the feed end of the rotary kiln 9, an electromagnetic heater is provided on the outer wall of the rotary kiln 9 (detailed drawing in the figure, this is the prior art, no further description is given, in addition, the rotary kiln 9 is provided with a supporting mechanism and a driving mechanism, which can rotate, which is also the prior art, no further description is given), to achieve electromagnetic heating,

[0026] The discharge port of the hopper 3 is connected to the feed port of the buffer bin 13 through the belt scale 2 and the conveyor 1. The discharge port of the buffer bin 13 is connected to the feed port of the preheating bin 17 through a control valve. The discharge port of the preheating bin 17 is connected to the feed end of the rotary kiln 9 through another control valve and the kiln chute. The conveyor 1 adopts a large-angle belt conveyor. Of course, a vertical elevator can also be used as needed. They are not listed one by one.

[0027] A serpentine heat exchange tube 16 is provided in the preheating chamber 17, the inlet of the serpentine heat exchange tube 16 is connected to the outlet of the carbon dioxide gas collecting chamber 12, and the outlet of the serpentine heat exchange tube 16 is connected to the second bag filter 6, and an electric cold air valve is provided on the connecting pipe to distribute air;

[0028] The inlet at the lower end of one side of the preheating bin 17 is connected to the outlet of the vertical cooler 11, and the outlet at the upper end of the other side of the preheating bin 17 is connected to the first bag filter 4, and an electric cold air valve is also provided on the connecting pipe.

[0029] Optimal solution: the control valve comprises a spiral gate valve 14 and a double-layer air lock valve 15, which are connected in series, and the spiral gate valve 14 is connected to the lower end of the bin body.

[0030] Preferred solution: The first bag filter 4 and the second bag filter 6 are respectively connected to the air compressor 5 and are respectively provided with regulating valves. The outlet of the second bag filter is connected to the carbon dioxide gas storage tank, and the carbon dioxide in the carbon dioxide gas storage tank can be used to make dry ice or directly exported.

[0031] Preferred solution: A fan 11 is provided on the vertical cooler 10, and the outlet of the first bag filter 4 is emptied.

[0032] Working process:

[0033] Limestone raw materials are transported to the site by trucks and stored in the stockpile shed for future use. During production, they are loaded into the hopper 3 by a forklift, and the limestone is weighed by the belt scale 2 under the hopper 3 and then sent to the limestone buffer bin 13 by the conveyor 1. During production, it is necessary to ensure that there is always material in the buffer bin 13 to avoid the occurrence of airflow short circuit events.

[0034] The material is preheated by two heat sources in the preheating bin 17 and fed into the rotary kiln 9 evenly through the control valve for calcination. The rotary kiln 9 adopts electromagnetic heating to accurately adjust the required calcination temperature. The speed of the rotary kiln 9 is adjustable within the range of 0.5-5.0r / min. The residence time of the limestone in the rotary kiln 9 can be adjusted at any time according to the size of the feed particle size and the quality of the product.

[0035] The carbon dioxide gas generated by calcining limestone exchanges heat with the limestone indirectly in the preheating chamber 17 through the carbon dioxide gas collecting chamber 12 and the serpentine heat exchange tube 16. The carbon dioxide after cooling, filtering and dust removal enters the carbon dioxide gas storage cabinet 7 and is transferred to the next process of making dry ice or selling it.

[0036] The hot air discharged from the vertical cooler 10 enters the preheating chamber 17 through the pipeline, directly exchanges heat with the limestone, and then is purified by the first bag filter 4 and discharged into the atmosphere.

[0037] The calcined lime enters the vertical cooler 10 and is rapidly cooled to below 100 degrees, and can then be discharged as a finished product.

[0038] The above is only a preferred embodiment of the utility model, and does not limit the utility model in any form. Any simple modification made according to the technical essence of the utility model still falls within the scope of the technical solution of the utility model.

Claims

1. A new lime production system using a preheating bin and an electrically heated rotary kiln, comprising a rotary kiln, a hopper, a conveyor, a belt scale and a buffer bin, characterized in that: The discharge end and the feed end of the rotary kiln are respectively provided with a vertical cooler and a carbon dioxide gas collecting chamber. An electromagnetic heater is provided on the outer wall of the rotary kiln to achieve electromagnetic heating. The discharge port of the hopper is connected to the feed port of the buffer bin through the belt scale and the conveyor, the discharge port of the buffer bin is connected to the feed port of the preheating bin through a control valve, and the discharge port of the preheating bin is connected to the feed end of the rotary kiln through another control valve and the kiln chute; A serpentine heat exchange tube is arranged in the preheating chamber, the inlet of the serpentine heat exchange tube is connected with the outlet of the carbon dioxide collecting chamber, and the outlet of the serpentine heat exchange tube is connected with the second bag dust collector; The inlet at the lower end of one side of the preheating bin wall is communicated with the outlet of the vertical cooler, and the outlet at the upper end of the other side of the preheating bin wall is communicated with the first bag dust collector.

2. A novel lime production system using a preheating bin and an electrically heated rotary kiln according to claim 1, characterized in that: The control valve comprises a spiral gate valve and a double-layer air lock valve, which are connected in series, and the spiral gate valve is connected to the lower end of the bin body.

3. The novel lime production system using a preheating bin and an electrically heated rotary kiln according to claim 1 is characterized in that: The first bag dust collector and the second bag dust collector are both connected to the air compressor, and are respectively provided with a regulating valve.

4. The novel lime production system using a preheating bin and an electrically heated rotary kiln according to claim 3 is characterized in that: The outlet of the second bag filter is connected to a carbon dioxide gas storage tank, and the carbon dioxide in the carbon dioxide gas storage tank can be used to make dry ice or directly exported.

5. The novel lime production system using a preheating bin and an electrically heated rotary kiln according to claim 1 is characterized in that: The conveyor is an inclined conveyor, a fan is provided on the vertical cooler, and the outlet of the first bag dust collector is emptied.

Images