Vertical calcium carbide furnace and calcium carbide synthesis preparation method thereof

Abstract

The invention discloses a vertical calcium carbide furnace and a calcium carbide synthesis preparation method thereof, and relates to the technical field of calcium carbide production.The vertical calcium carbide furnace comprises a spiral feeder, a feeding port is formed in the upper portion of the spiral feeder, and a feeding pipe arranged at the bottom of the spiral feeder downwards extends into a low-temperature section in a furnace shell; a preheating section, a high-temperature section, a slow cooling section and a cooling section are vertically and sequentially arranged below the low-temperature section and in the furnace shell, a water-cooling spiral discharger is arranged at the bottom of the cooling section and outside the spiral feeder, and a discharge port is formed in the bottom of the water-cooling spiral discharger. In order to solve the problems, the vertical calcium carbide furnace and the calcium carbide synthesis and preparation method thereof are provided, the temperature in a single furnace chamber is stable, the fluctuation of the furnace gas amount is small, gas in different furnace chambers is independently collected and is convenient for subsequent reutilization, and the gas in the high-temperature furnace chamber is mainly high-purity carbon monoxide.

Description

Technical Field

[0001] The invention relates to the technical field of calcium carbide production, in particular to a vertical calcium carbide furnace and a method for synthesizing and preparing calcium carbide. Background Art

[0002] Calcium carbide production is a high-energy-consuming and high-pollution industry. Under the background of "dual carbon", the task of energy conservation and emission reduction in the industry is very arduous, facing a series of pressures such as structural adjustment, environmental protection, energy conservation and emission reduction, and elimination of backward production capacity. Therefore, exploring energy-saving and carbon-reducing paths for calcium carbide production has played a positive role in promoting the green, healthy and sustainable development of the entire industry.

[0003] The existing calcium carbide production equipment and preparation methods have the following technical problems:

[0004] 1. High energy consumption, it is difficult to meet the industry's comprehensive energy consumption requirements, the benchmark level is 805 kg standard coal / ton, and the baseline level is 940 kg standard coal / ton;

[0005] 2. The sensible heat of calcium carbide and the heat energy of furnace cover are not recovered, and the temperature of furnace wall is too high;

[0006] 3. 2100℃ hot discharge, harsh working environment, and the risk of carbon monoxide leakage;

[0007] 4. Large temperature fluctuations, poor product consistency, and unstable gas emission;

[0008] 5. The degree of automation is low, and the discharging and cooling cannot achieve continuous feeding and discharging operations.

[0009] The present invention is mainly to solve the above problems. We use a triple combination of carbon black, carbon fiber hard felt and aerogel insulation material for the furnace wall to ensure that the furnace wall temperature is not higher than the ambient temperature + 20°C. The inlet and outlet materials both adopt a transition bin structure. The transition bin is evacuated and argon is replaced to ensure that air is not brought into the furnace and carbon monoxide does not leak out. Summary of the invention

[0010] The purpose of the present invention is to provide a vertical calcium carbide furnace and a method for synthesizing calcium carbide in view of the above problems. The temperature in a single furnace chamber is stable, the furnace gas volume fluctuates little, and the gases in different furnace chambers are collected separately for subsequent reuse. The high-temperature furnace chamber gas is mainly high-purity carbon monoxide.

[0011] To achieve the above object, the technical solution adopted by the present invention is:

[0012] A vertical calcium carbide furnace comprises a screw feeder, a feed port is arranged on the upper part of the screw feeder, a feeding pipe arranged at the bottom of the screw feeder extends downward into a low-temperature section in a furnace shell, a preheating section, a high-temperature section, a slow cooling section and a cooling section are arranged vertically in sequence below the low-temperature section and in the furnace shell, a water-cooled screw discharging device is arranged at the bottom of the cooling section and outside the screw feeder, a discharge port is arranged at the bottom of the water-cooled screw discharging device, and the wall structure of the furnace shell is a composite structure composed of three thermal insulation materials: carbon black, carbon fiber hard felt and aerogel.

[0013] As a further improvement of the above solution, butterfly valves are provided between the preheating section and the high temperature section, and between the high temperature section and the slow cooling section.

[0014] As a further improvement of the above solution, a motor and an infrared temperature measuring port are arranged on the side of the preheating section and inside the furnace shell.

[0015] As a further improvement of the above solution, a microwave generator is arranged on the side of the high temperature section and inside the furnace shell, and an exhaust pipe for discharging tail gas in the furnace shell is arranged on the upper part of the high temperature section.

[0016] As a further improvement of the above scheme, the feed port at the upper part of the screw feeder is connected to the feed system, and the feed system includes a feeding tank, and a first electric ball valve, a buffer tank and a second electric ball valve are sequentially arranged at the lower part of the feeding tank.

[0017] As a further improvement of the above solution, the temperature at the low temperature section is controlled to be 25-800°C.

[0018] As a further improvement of the above solution, the temperature at the low temperature section is controlled to be 800-1500°C.

[0019] As a further improvement of the above solution, the temperature at the high temperature section is controlled to be 1500-1800°C.

[0020] A method for synthesizing calcium carbide for a vertical calcium carbide furnace comprises the following steps:

[0021] Step A: The calcite material is subjected to ultrafine grinding operation, and sent to the feeding bin and the metering bin for mixing and batching operation;

[0022] Step B: granulating and drying the mixed materials, and sending them into a vertical calcium carbide furnace for reaction. Calcium carbonate is decomposed at high temperature to produce calcium oxide and carbon dioxide, and calcium oxide and carbon are combined at high temperature to produce calcium carbide;

[0023] Step C: The generated calcium carbide material is discharged from the water-cooled spiral discharger;

[0024] Step D: storing the calcium carbide material and packaging it using automatic packaging equipment.

[0025] Compared with the prior art, the invention has the following beneficial effects: providing a vertical calcium carbide furnace and a method for synthesizing calcium carbide, wherein the temperature in a single furnace chamber is stable, the furnace gas volume fluctuates slightly, the gases in different furnace chambers are collected separately, which is convenient for subsequent reuse, and the high-temperature furnace chamber gas is mainly high-purity carbon monoxide;

[0026] 1. High thermal efficiency, equipped with a feeding system, adopting full continuous feeding and discharging, with slow cooling zone and cooling zone, the sensible heat of calcium carbide can be fully utilized and recovered; due to the vertical structure, high-temperature materials can preheat low-temperature materials, and the high-temperature materials in the cooling zone can achieve the purpose of waste heat recovery through the steam heat exchanger;

[0027] 2. High safety performance. The feed is replaced by argon. The oxygen content of the whole system is controlled below 500ppm. The furnace cover has no water jacket mechanism. The furnace pressure range is -1000-2000pa, and there is no risk of explosion. The mixed material is first loaded into the feed tank, the first electric ball valve is opened, the material enters the buffer tank, the first electric ball valve is closed, vacuum is drawn, argon is replaced, the second electronic ball valve is opened, the material enters the screw feeder, and is sent into the rotating rotary tube at a certain speed (digital display indication) (digital display adjustment, adjustable speed).

[0028] 3. Tail gas treatment: Different temperature zones have different tail gas treatment methods. The gas composition analysis produced in the high temperature zone is shown in the following table:

[0029] CO(%) <![CDATA[H2(%)]]> Ar(％) <![CDATA[CO2(%)]]> 99.2 0.3 0.3 0.2

[0030] 4. The temperature uniformity can be controlled within ±10℃, the product consistency is good, and the gas emission is high; the heating method is external heating, using graphite as the heating element, the temperature is controllable, and the range is 1790-1810℃.

[0031] 5. The discharge temperature is controlled below 60℃, and it is in granular form. It does not need to be crushed and can be automatically packaged. The discharge temperature is mainly controlled by the cooling section and the water-cooled spiral discharge section. The water inlet temperature of the cooling section is controlled at ≤30℃, and the heat exchange area is ≥5 square meters / ton of material. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the main structure of the vertical calcium carbide furnace of the present invention.

[0033] Figure 2 It is a schematic diagram of the main structure of the vertical calcium carbide furnace feeding system of the present invention.

[0034] Figure 3 It is a schematic diagram of the main structure of the lower half of the vertical calcium carbide furnace of the present invention.

[0035] Figure 4 The present invention is a schematic diagram of the method for synthesizing and preparing calcium carbide.

[0036] The text labels in the figure indicate: 1. screw feeder; 2. low temperature section; 3. preheating section; 4. exhaust pipe; 5. high temperature section; 6. slow cooling section; 7. butterfly valve; 8. water-cooled screw discharger; 9. microwave generator; 10. infrared temperature measuring port; 11. motor; 12. cooling section; 13. furnace shell; 14. feeding system; 1401. feeding tank; 1402. first electric ball valve; 1403. buffer tank; 1404. second electric ball valve. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solution, the present invention is described in detail below in conjunction with embodiments. The description in this section is only exemplary and explanatory and should not have any limiting effect on the scope of protection of the present invention.

[0038] like Figure 1-4 As shown, the specific scheme of this embodiment is: a vertical calcium carbide furnace, including a screw feeder 1, a feed port is arranged on the upper part of the screw feeder 1, a feeding pipe arranged at the bottom of the screw feeder 1 extends downward into the low-temperature section 2 in the furnace shell 13, a preheating section 3, a high-temperature section 5, a slow cooling section 6, and a cooling section 12 are arranged vertically in sequence below the low-temperature section 2 and in the furnace shell 13, a water-cooled screw discharging device 8 is arranged at the bottom of the cooling section 12 and outside the screw feeder 1, a discharge port is arranged at the bottom of the water-cooled screw discharging device 8, and the wall structure of the furnace shell 13 is a composite structure composed of three kinds of thermal insulation materials: carbon black, carbon fiber hard felt and aerogel.

[0039] like Figure 1 As shown, as a preferred embodiment of the above embodiment, butterfly valves 7 are provided between the preheating section 3 and the high temperature section 5 , and between the high temperature section 5 and the slow cooling section 6 .

[0040] like Figure 1 As shown, as a preferred embodiment of the above embodiment, a motor 11 and an infrared temperature measuring port 10 are arranged on the side of the preheating section 3 and inside the furnace shell 13 .

[0041] like Figure 1 As shown, as a preferred embodiment of the above embodiment, a microwave generator 9 is arranged on the side of the high temperature section 5 and inside the furnace shell 13 , and an exhaust pipe 4 for discharging tail gas in the furnace shell 13 is arranged on the upper part of the high temperature section 5 .

[0042] like Figure 1 As shown, as a preferred embodiment of the above embodiment, the feed port at the top of the screw feeder 1 is connected to the feed system 14, and the feed system 14 includes a feeding tank 1401, and a first electric ball valve 1402, a buffer tank 1403 and a second electric ball valve 1404 are sequentially arranged at the lower part of the feeding tank 1401.

[0043] like Figure 1 As shown, as a preferred embodiment of the above embodiment, the temperature at the low temperature section 2 is controlled to be 25-800°C.

[0044] like Figure 1 As shown, as a preferred embodiment of the above embodiment, the temperature at the low temperature section 2 is controlled to be 800-1500°C.

[0045] like Figure 1 As shown, as a preferred embodiment of the above embodiment, the temperature at the high temperature section 5 is controlled to be 1500-1800°C.

[0046] like Figure 1 As shown, a method for preparing calcium carbide synthetically for a vertical calcium carbide furnace comprises the following preparation steps:

[0047] Step A: The calcite material is subjected to ultrafine grinding operation, and sent to the feeding bin and the metering bin for mixing and batching operation;

[0048] Step B: granulating and drying the mixed materials, and sending them into a vertical calcium carbide furnace for reaction. Calcium carbonate is decomposed at high temperature to produce calcium oxide and carbon dioxide, and calcium oxide and carbon are combined at high temperature to produce calcium carbide;

[0049] Step C: The generated calcium carbide material is discharged from the water-cooled spiral discharger 8;

[0050] Step D: storing the calcium carbide material and packaging it using automatic packaging equipment.

[0051] The furnace gas composition of the present invention is shown in the following table:

[0052] Furnace gas composition

[0053]

[0054] The data comparison between the gas generation volume of the present invention using the traditional process and the new process of the present application is shown in the following figure:

[0055]

[0056] Compared with the prior art solutions, the present invention has the following advantages:

[0057] Provided are a vertical calcium carbide furnace and a method for synthesizing calcium carbide. The temperature in a single furnace chamber is stable, the furnace gas volume fluctuates slightly, the gases in different furnace chambers are collected separately, which is convenient for subsequent reuse. The high-temperature furnace chamber gas is mainly high-purity carbon monoxide.

[0058] 1. High thermal efficiency. A feeding system 14 is provided. Fully continuous feeding and discharging is adopted. There is a slow cooling zone and a cooling zone. The sensible heat of calcium carbide can be fully utilized and recovered. Due to the vertical structure, high-temperature materials can preheat low-temperature materials. The high-temperature materials in the cooling zone can achieve the purpose of waste heat recovery through the steam heat exchanger.

[0059] 2. High safety performance. The feed is replaced by argon. The oxygen content of the whole system is controlled below 500ppm. The furnace cover has no water jacket mechanism. The furnace pressure range is -1000-2000pa, and there is no risk of explosion. The mixed material is first loaded into the feed tank 1401, and the first electric ball valve 1402 is opened. The material enters the buffer tank, and the first electric ball valve 1402 is closed. Vacuuming, argon replacement, and the second electronic ball valve 1404 are opened. The material enters the screw feeder 1 and is sent into the rotating rotary tube at a certain speed (digital display indication) (digital display adjustment, adjustable speed).

[0060] 3. Tail gas treatment: Different temperature zones have different tail gas treatment methods. The gas composition analysis produced in the high temperature zone is shown in the following table:

[0061] CO(%) <![CDATA[H2(%)]]> Ar(％) <![CDATA[CO2(%)]]> 99.2 0.3 0.3 0.2

[0062] 4. The temperature uniformity can be controlled within ±10℃, the product consistency is good, and the gas emission is high; the heating method is external heating, using graphite as the heating element, the temperature is controllable, and the range is 1790-1810℃.

[0063] 5. The discharge temperature is controlled below 60℃, and it is in granular form. It does not need to be crushed and can be automatically packaged. The discharge temperature is mainly controlled by the cooling section and the water-cooled spiral discharge section. The water inlet temperature of the cooling section is controlled at ≤30℃, and the heat exchange area is ≥5 square meters / ton of material.

[0064] It should be noted that, in this article, the terms include, contain or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. Specific examples are used in this article to illustrate the principle and implementation of the technical solution of the present invention. The above examples are only used to help understand the method of the present invention and its core idea. The above is only a preferred implementation of the present invention. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements, modifications or changes can be made, and the above technical features can also be combined in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of the invention to other occasions without improvement, should be regarded as the protection scope of the present invention.

Claims

1. A vertical calcium carbide furnace, characterized in that: The invention comprises a screw feeder (1), a feed port is arranged at the top of the screw feeder (1), a feed pipe is arranged at the bottom of the screw feeder (1) and extends downward into a low-temperature section (2) in a furnace shell (13), a preheating section (3), a high-temperature section (5), a slow cooling section (6), and a cooling section (12) are arranged vertically in sequence below the low-temperature section (2) and in the furnace shell (13), a water-cooled screw discharger (8) is arranged at the bottom of the cooling section (12) and outside the screw feeder (1), a discharge port is arranged at the bottom of the water-cooled screw discharger (8), and the wall structure of the furnace shell (13) is a composite structure composed of three thermal insulation materials: carbon black, carbon fiber hard felt and aerogel.

2. A vertical calcium carbide furnace according to claim 1, characterized in that: Butterfly valves (7) are provided between the preheating section (3) and the high temperature section (5), and between the high temperature section (5) and the slow cooling section (6).

3. A vertical calcium carbide furnace according to claim 1, characterized in that: A motor (11) and an infrared temperature measuring port (10) are arranged on the side of the preheating section (3) and inside the furnace shell (13).

4. A vertical calcium carbide furnace according to claim 1, characterized in that: A microwave generator (9) is arranged on the side of the high temperature section (5) and inside the furnace shell (13), and an exhaust pipe (4) for exhausting tail gas in the furnace shell (13) is arranged on the top of the high temperature section (5).

5. A vertical calcium carbide furnace according to claim 1, characterized in that: The feed port at the upper part of the screw feeder (1) is connected to the feed system (14), and the feed system (14) comprises a feeding tank (1401), and a first electric ball valve (1402), a buffer tank (1403) and a second electric ball valve (1404) are sequentially arranged at the lower part of the feeding tank (1401).

6. A vertical calcium carbide furnace according to claim 1, characterized in that: The temperature at the low temperature section (2) is controlled to be 25-800°C.

7. A vertical calcium carbide furnace according to claim 1, characterized in that: The temperature at the low temperature section (2) is controlled to be 800-1500°C.

8. A vertical calcium carbide furnace according to claim 1, characterized in that: The temperature at the high temperature section (5) is controlled to be 1500-1800°C.

9. A method for synthesizing calcium carbide used in the vertical calcium carbide furnace of claim 1, characterized in that: The method comprises the following preparation steps: Step A: The calcite material is subjected to ultrafine grinding operation, and sent to the feeding bin and the metering bin for mixing and batching operation; Step B: granulating and drying the mixed materials, and sending them into a vertical calcium carbide furnace for reaction. Calcium carbonate is decomposed at high temperature to produce calcium oxide and carbon dioxide, and calcium oxide and carbon are combined at high temperature to produce calcium carbide; Step C: the generated calcium carbide material is discharged from the water-cooled spiral discharger (8); Step D: storing the calcium carbide material and packaging it using automatic packaging equipment.

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