Calcium carbide slag suspension roasting system

Abstract

The present disclosure relates to a calcium carbide slag suspension calcination system, which comprises a raw material bin, a suspension calciner and a first cyclone separator. The suspension calciner comprises a main combustion zone and a burn-out zone located above the main combustion zone along the extension direction thereof; the main combustion zone is configured to perform under-oxygen calcination of calcium carbide slag from the raw material bin in the main combustion zone; the burn-out zone is configured to perform calcination of the calcium carbide slag after the under-oxygen calcination in the main combustion zone in the burn-out zone; the first cyclone separator is configured to communicate with the outlet of the suspension calciner to perform gas-solid separation; the separated solid phase is configured to be fed into the suspension calciner in a proportionally adjustable manner for repeated calcination, and into a cooling system for cooling to form active calcium oxide or over-burned calcium oxide. The system reduces the generation of nitrogen oxides in the calcination process by using multi-zone calcination, and can adjust the circulation ratio according to the requirements to selectively produce active calcium oxide or over-burned calcium oxide, thereby improving the diversity of the calcination products.

Description

Technical Field

[0001] This disclosure relates to the field of chemical building materials production technology, and in particular to a calcium carbide slag suspension roasting system. Background Technology

[0002] In recent years, with the continuous upgrading of production technology, a large amount of calcium carbide slag is generated during the production process using calcium carbide. The main component of calcium carbide slag is calcium hydroxide, and it may also contain magnesium, aluminum, iron, silicon and other substances. It is a recyclable material.

[0003] Among the various ways to recycle and utilize calcium carbide slag, one is to use calcium carbide slag roasting to prepare active calcium oxide and overburned calcium oxide. In the existing technology, in order to ensure the roasting effect of calcium carbide slag, excessive heat is often required to ensure that the calcium carbide slag is completely roasted, which consumes a lot of fuel and increases production costs. At the same time, a large amount of nitrogen oxides are also generated in the process of using calcium carbide slag for production. Summary of the Invention

[0004] This disclosure provides a calcium carbide slag suspension roasting system to address the problems existing in the prior art.

[0005] According to a first aspect of this disclosure, a calcium carbide slag suspension roasting system is provided, comprising:

[0006] Raw material warehouse;

[0007] A suspension roasting furnace, the suspension roasting furnace including a main combustion zone and a burnout zone located above the main combustion zone along its extension direction; the main combustion zone is configured to perform anaerobic roasting of carbide slag from the raw material silo in the main combustion zone; the burnout zone is configured to roast the carbide slag after anaerobic roasting in the main combustion zone in the burnout zone.

[0008] A first cyclone separator is configured to communicate with the outlet of the suspension roasting furnace for gas-solid separation; the separated solid phase is configured to be fed into the suspension roasting furnace in a proportionally adjustable manner for repeated roasting, and to be fed into a cooling system for cooling, to form active calcium oxide or overburned calcium oxide.

[0009] In one embodiment of this disclosure, the suspension roasting furnace further includes a burner extending into the main combustion zone, the burnout zone being configured to be positioned at a predetermined height from the burner.

[0010] In one embodiment of this disclosure, the cooling system includes at least one cyclone cooler, wherein the solid phase exiting the first cyclone separator sequentially enters the at least one cyclone cooler for cooling.

[0011] In one embodiment of this disclosure, the external airflow is preheated after passing through at least one stage of cyclone cooler in reverse order, and the preheated airflow is at least partially introduced into the main combustion zone to perform anaerobic roasting of the carbide slag from the raw material silo in the main combustion zone.

[0012] In one embodiment of this disclosure, at least a portion of the preheated gas flow is introduced into the burnout zone to roast the carbide slag after oxygen-deficient roasting.

[0013] In one embodiment of this disclosure, the cyclone cooler includes a first cyclone cooler, a second cyclone cooler, and a third cyclone cooler connected in sequence; the solid phase is cooled by passing through the first cyclone cooler, the second cyclone cooler, and the third cyclone cooler in sequence, while the external airflow is preheated after passing through the third cyclone cooler, the second cyclone cooler, and the first cyclone cooler in reverse sequence.

[0014] In one embodiment of this disclosure, a purification device is also included, wherein the solid phase cooled by the cyclone cooler is configured to be purified in the purification device.

[0015] In one embodiment of this disclosure, the impurity removal device is an air classifier, which is configured to screen the solid phase by air classification, and the screened finished product is configured to enter the finished product silo through a bag filter.

[0016] In one embodiment of this disclosure, a crushing device is also included, wherein the calcium carbide slag in the raw material silo is crushed by the crushing device and then sent to the suspension roasting furnace for roasting.

[0017] In one embodiment of this disclosure, a preheating system is also included, which includes at least one stage of cyclone preheater. The carbide slag crushed by the crushing device is configured to be preheated by at least one stage of cyclone preheater before entering the suspension roasting furnace for roasting.

[0018] In one embodiment of this disclosure, the flue gas separated from the cyclone separator is configured to pass through the cyclone preheater to preheat the carbide slag located in the cyclone preheater.

[0019] In one embodiment of this disclosure, the flue gas exiting the cyclone preheater is configured to enter the crushing device to dry the carbide slag in the crushing device.

[0020] In one embodiment of this disclosure, a second cyclone separator is also included, wherein the dried carbide slag in the crushing device is configured to undergo gas-solid separation in the second cyclone separator; the separated solid phase enters a cyclone preheater for preheating; and the separated flue gas is configured to be collected by a bag filter.

[0021] In one embodiment of this disclosure, a reheating furnace is also included, which is used to dry the carbide slag in the crushing device in an adjustable manner.

[0022] In one embodiment of this disclosure, an adjusting device is also included, which is configured to adjust the proportion of solid phase entering the suspension roasting furnace for repeated roasting and entering the cooling system for cooling.

[0023] One beneficial effect of this disclosure is that the system utilizes multi-zone roasting to reduce the generation of nitrogen oxides during the roasting process and improve the uniformity of furnace temperature. In addition, the circulation ratio can be adjusted according to needs to selectively produce active calcium oxide or overburned calcium oxide, thereby increasing the diversity of roasted products.

[0024] Other features and advantages of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the present disclosure and, together with their description, serve to explain the principles of the present disclosure.

[0026] Figure 1 This is a schematic diagram of the structure of a suspension roasting furnace provided in one embodiment of the present disclosure;

[0027] Figure 2 This is a schematic diagram of the structure of a crushing device provided in an embodiment of this disclosure;

[0028] Figure 3 This is a schematic diagram of the structure of a second cyclone separator provided in an embodiment of this disclosure;

[0029] Figure 4 This is a schematic diagram of the structure of a cooling system provided in an embodiment of this disclosure;

[0030] Figure 5 This is a schematic diagram of the structure of a purification device provided in an embodiment of this disclosure;

[0031] Figure 6 This is a schematic diagram of the structure of a calcium carbide slag suspension roasting system provided in one embodiment of this disclosure.

[0032] Figures 1 to 6 The one-to-one correspondence between the component names and the reference numerals in the attached figures is as follows:

[0033] 1-Raw material silo, 2-Suspension roasting furnace, 211-Burner, 212-First air inlet, 221-Second air inlet, 23-First feed inlet, 24-Outlet of suspension roasting furnace, 25-Second feed inlet, 3-First cyclone separator, 4-Crushing device, 5-Reheating furnace, 6-Cyclone preheater, 7-Second cyclone separator, 81-First cyclone cooler, 82-Second cyclone cooler, 83-Third cyclone cooler, 9-Impurity removal device, 101-Bag filter dust collector, 102-Exhaust fan, 103-Chimney, 104-Conveyor belt, 105-Bucket elevator, 106-Finished product silo. Detailed Implementation

[0034] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0035] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0036] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0037] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0038] The specific embodiments of this disclosure are described below with reference to the accompanying drawings.

[0039] In this article, terms such as "up," "down," "front," "back," "left," and "right" are used only to indicate the relative positional relationship between related parts, rather than to define the absolute position of these related parts.

[0040] In this article, "first," "second," etc., are used only to distinguish one another, and not to indicate degree of importance, order, or prerequisite for each other.

[0041] In this document, terms such as “equal” and “same” are not strict mathematical and / or geometric limitations, but also include errors that are understandable to those skilled in the art and permissible in manufacturing or use.

[0042] The calcium carbide slag suspension roasting system disclosed herein includes a raw material silo, a suspension roasting furnace, and a first cyclone separator. The raw material silo is used to store calcium carbide slag raw materials. Measuring instruments can also be installed in the raw material silo or at the outlet end of the raw material silo to measure data related to the production process, such as the quality and moisture content of the calcium carbide slag.

[0043] The suspension roasting furnace includes a main combustion zone and a burnout zone, which are arranged along the extension direction of the furnace. The burnout zone is located above the main combustion zone. Alternatively, the main combustion zone and burnout zone can be understood as being arranged along the extension direction of the flue gas within the furnace. The flue gas and calcium carbide slag raw material pass through the main combustion zone and the burnout zone sequentially. The main combustion zone is the area where anaerobic combustion occurs, and the calcium carbide slag raw material undergoes anaerobic roasting in the main combustion zone, reducing the formation of nitrogen oxides during this process. The burnout zone is the area where the fuel undergoes complete combustion. The calcium carbide slag raw material continues to be roasted in the burnout zone; that is, the fuel that was not burned in the main combustion zone is completely burned in the burnout zone, and the calcium carbide slag raw material is roasted under the condition that the fuel is completely burned.

[0044] The first cyclone separator is configured to connect to the outlet of the suspension roasting furnace, which discharges flue gas containing the solid phase of the carbide slag raw material after roasting. The first cyclone separator is configured to perform gas-solid separation of the flue gas. The separated solid phase is fed into the suspension roasting furnace for repeated roasting in an adjustable proportion, and then sent to a cooling system for cooling to form active calcium oxide or overburned calcium oxide.

[0045] Therefore, the calcium carbide slag suspension roasting system disclosed herein reduces the generation of nitrogen oxides and improves the uniformity of furnace temperature by using a suspension roasting furnace for oxygen-deficient roasting in the main combustion zone and roasting in the burnout zone, and by sending the separated solid phase into the suspension roasting furnace for repeated roasting through a first cyclone separator. In addition, the roasting stroke and roasting time of the calcium carbide slag raw material can be increased based on the original equipment, so that the overburning degree of the calcium carbide slag raw material can be controlled.

[0046] For ease of understanding, please refer to the following: Figures 1 to 6 The specific structure and working principle of this disclosure will be explained in detail with reference to the embodiments.

[0047] refer to Figure 1 and Figure 2 In one embodiment of this disclosure, the system includes a raw material drying system, a preheating system, a roasting system, a cooling system, and a purification system. The system also includes a raw material silo 1, a suspension roasting furnace 2, and a first cyclone separator 3.

[0048] Raw material silo 1 can be used to store carbide slag. The specific structure of the raw material silo can be a small, medium or large warehouse structure commonly used in this field, or a warehouse cluster composed of multiple warehouses. Depending on the specific production requirements, raw material silo 1 can also be used to store other raw materials in addition to carbide slag, and there are no restrictions on this.

[0049] The suspension roasting furnace 2 includes a furnace chamber, which serves as the main area for roasting carbide slag. Following the direction of the furnace's extension, the furnace chamber can be divided into a main combustion zone 21 and a burnout zone 22, with the burnout zone 22 located above the main combustion zone 21. The main combustion zone 21 is configured for oxygen-deficient roasting of the carbide slag from the raw material silo 1. Oxygen-deficient roasting can be understood as the fuel introduced into the main combustion zone 21 generating heat to roast the carbide slag under oxygen-deficient combustion conditions. Oxygen-deficient combustion refers to insufficient combustion air to completely burn the fuel, thereby reducing the formation of nitrogen oxides from the combination of nitrogen and oxygen at high temperatures. Simultaneously, a large amount of reducing substances containing HCN, OH, and CH are generated in the oxygen-deficient environment, further reducing nitrogen oxides and minimizing their formation.

[0050] The burnout zone 22 is configured to roast the carbide slag after it has been roasted in the main combustion zone 21. This can be understood as the unburned fuel in the main combustion zone 21 being completely burned in the burnout zone 22, further increasing the heat and causing the carbide slag after roasting in the main combustion zone 21 to be further roasted to obtain the final product. In one embodiment of this disclosure, the carbide slag, after passing through the main combustion zone and the burnout zone, is roasted into calcium oxide.

[0051] It should be noted that in this disclosure, the oxygen-deficient combustion in the main combustion zone 21 has already burned most of the fuel. The reducing substances generated in this process can reduce the nitrogen oxides generated during the roasting process. A small amount of fuel will remain in the burnout zone 22, and only a small amount of combustion air is needed to completely burn the fuel. Compared with the roasting process of the prior art, even though a small amount of nitrogen oxides will still be generated in this process, the combination of the main combustion zone 21 and the burnout zone 22 reduces the overall generation of nitrogen oxides in the process. Under this structure, the furnace temperature is also more uniform, improving production stability and product quality.

[0052] See also Figure 1The main combustion zone 21 of the furnace includes a burner 211 extending into the main combustion zone and a first air inlet 212. The burner 211 can supply fuel, such as gas or pulverized coal, to the main combustion zone 21 to provide heat. The burner 211 can also ignite the fuel supplied to the main combustion zone 21 in the presence of combustion air. The first air inlet 212 is configured to supply combustion air to the main combustion zone to provide a combustion environment for the fuel. The first air inlet 212 can also have an adjustment function to adjust the amount of combustion air supplied to the main combustion zone 21. In this disclosure, the first air inlet 211 is configured to supply insufficient amount of combustion air to the main combustion zone 21, so that the fuel supplied to the main combustion zone 21 undergoes oxygen-deficient combustion.

[0053] See also Figure 1 The furnace also includes a first feed inlet 23 connected to an external feed pipe. The external feed pipe is used to transport calcium carbide slag from the raw material silo or to connect to the pretreatment equipment for calcium carbide slag. In order to better roast the calcium carbide slag, appropriate pretreatment can be carried out before roasting, such as breaking up, drying, and preheating the calcium carbide slag raw material, so as to improve the roasting effect of the calcium carbide slag and facilitate product preparation. The first feed inlet 23 is located at the corresponding position of the main combustion zone 21. For example, it can be located above the burner 211 in the main combustion zone 21, so that after the calcium carbide slag enters the main combustion zone 21 through the first feed inlet 23, it will fall above the flame emitted by the burner 211 and be carried by the flue gas towards the burnout zone 22.

[0054] See also Figure 1 After being roasted in the main combustion zone 21, the carbide slag enters the burnout zone 22. The burnout zone 22 is located at a predetermined height from the burner. A second air inlet 221 is provided on the side wall of the burnout zone 22. The second air inlet 221 is configured to introduce combustion air, so that the fuel entering the burnout zone 22 from the main combustion zone 21 is completely burned. The complete combustion of the fuel further increases the heat and ensures the roasting effect of the carbide slag.

[0055] In the above process, see Figure 1 The flue gas generated by combustion in the main combustion zone 21 is ejected upwards, which in turn drives the carbide slag that enters the main combustion zone 21 from the first feed inlet 23 to move upwards. Combustion air is further introduced into the burnout zone 22. While the carbide slag roasted in the main combustion zone 21 is being roasted, the flue gas generated will further drive the solid phase generated after roasting to move upwards. Finally, the solid phase generated after roasting is discharged from the outlet 24 of the suspension roasting furnace 2 along with the flue gas.

[0056] See also Figure 1The first cyclone separator 3 is connected to the outlet of the suspension roasting furnace 2. The solid phase generated by the roasting in the suspension roasting furnace 2 and the flue gas enter the first cyclone separator 3 together. The first cyclone separator 3 will perform gas-solid separation to separate the solid phase for further processing.

[0057] According to actual production needs, the separated solid phase is configured to be fed into the suspension roasting furnace 2 in an adjustable proportion for repeated roasting, and then fed into the cooling system for cooling to form active calcium oxide or overburned calcium oxide.

[0058] For details, see Figure 1 A second feed inlet 25 is also provided on the side wall of the suspension roasting furnace 2. The solid phase outlet of the first cyclone separator 3 has two pipes, one of which is connected to the second feed inlet 25 to send the separated solid phase into the suspension roasting furnace 2 for repeated roasting, and the other is connected to the cooling system to send the separated solid phase into the cooling system for cooling. The proportion of solid phase entering the suspension roasting furnace 2 for repeated roasting and entering the cooling system for cooling can be adjusted by a regulating device. This regulating device can be, for example, a regulating valve, which can send part of the separated solid phase into the suspension roasting furnace 2 for repeated roasting and part of the solid phase into the cooling system for cooling, thereby obtaining an overburned product, namely overburned calcium oxide.

[0059] The proportion of material entering the suspension roasting furnace 2 can be controlled by adjusting the regulating valve, thereby achieving the purpose of adjusting the material circulation ratio. By adjusting the appropriate material circulation ratio, the calcium carbide slag suspension roasting system of this disclosure can be controlled to produce overburned calcium oxide.

[0060] In another embodiment of this disclosure, the solid phase separated by the first cyclone separator 3 may not be sent to the suspension roasting furnace 2 for over-burning, but instead is entirely sent to the cooling system for cooling. When it is necessary to roast carbide slag to produce active lime, the mixture from the suspension roasting furnace 2, after being separated by the first cyclone separator 3, is entirely sent to the cooling system for cooling, and the finished product is active lime. When it is necessary to roast carbide slag to produce over-burned lime, the mixture from the suspension roasting furnace 2, after being separated by the first cyclone separator 3, has a portion of the material sent back to the suspension roasting furnace 2 for repeated roasting. The number of cycles can be determined according to specific parameters, as long as it meets the requirement of producing over-burned lime. The over-burned lime separated from the first cyclone separator 3 then enters the cooling system for cooling.

[0061] The system disclosed herein can produce active lime or overburned lime through a suspension roasting furnace 2 without increasing the furnace length, thereby improving the diversity of roasted products.

[0062] In actual production, to ensure production quality, the calcium carbide slag needs to undergo appropriate treatment before roasting. (See [link to relevant documentation]). Figure 2 In one embodiment of this disclosure, a crushing device 4 and a supplementary heating furnace 5 are further disposed between the raw material silo 1 and the suspension roasting furnace 2. The crushing device 4 is connected to the raw material silo 1 and is configured to crush the carbide slag from the raw material silo 1; the supplementary heating furnace 5 is connected to the crushing device 4 and is configured to supply heat to the crushing device 4 in a power-adjustable manner to dry the crushed carbide slag in the crushing device 4. Thus, the suspension roasting furnace 2 is configured to roast the crushed carbide slag and to pass the flue gas generated after roasting into the crushing device 4 to dry the carbide slag in the crushing device 4.

[0063] With this configuration, when the moisture content of the carbide slag changes, the fuel and air volume of the suspension roasting furnace 2 do not need to be adjusted; only the supplementary heating furnace needs to be adjusted. This can maintain the stability of the roasting furnace's operating conditions, improve production stability, and enhance product quality.

[0064] For details, see Figure 2 The crushing device 4 can be connected to the raw material silo 1 via a conveying device. The conveying device can also have a metering function to measure the carbide slag entering the crushing device 4. For example, the conveying device can be a metering belt. Alternatively, the carbide slag in the raw material silo 1 can be sent into the crushing device 4 via a transport device. There are various ways to transfer the carbide slag from the raw material silo 1 to the crushing device 4, and there is no limitation on this.

[0065] The crushing device 4 has the function of crushing calcium carbide slag from a binder mass into small powder particles. It can transform calcium carbide slag from a binder mass into small powder particles through hammering, rolling, etc., to facilitate the calcination of calcium carbide slag. The crushing device 4 also has a drying function. During the crushing process of calcium carbide slag, external hot flue gas can be introduced to dry and heat the calcium carbide slag, thereby achieving the effects of drying and preheating, which facilitates the subsequent processing of calcium carbide slag. For example, the crushing device 4 can be a drying crusher, which can dry the crushed calcium carbide slag at the same time.

[0066] In one embodiment of this disclosure, the external hot air or hot flue gas for the crushing device 4 can be supplied jointly by the supplementary heating furnace 5 and the suspension roasting furnace 2. The supplementary heating furnace 5 can be a hot blast stove, which generates hot air through combustion. The hot air blown out by the hot blast stove can be combined with the flue gas generated after roasting in the suspension roasting furnace 2 and then introduced into the crushing device 4 to dry the crushed carbide slag in the crushing device 4.

[0067] For details, see Figure 2The gas pipes from the reheating furnace 5 and the gas pipes from the suspension roasting furnace 2 merge and enter the air inlet pipe of the crushing device 4, thereby jointly drying the crushed carbide slag in the crushing device 4.

[0068] The drying of carbide slag is related to the moisture content of the carbide slag itself. As those skilled in the art know, the lower the moisture content of the carbide slag, the less heat is required; the higher the moisture content of the carbide slag, the more heat is required.

[0069] Therefore, in one embodiment of this disclosure, when the moisture content of the calcium carbide slag is less than a threshold, the calcium carbide slag can be dried solely by the flue gas generated after roasting in the suspension roasting furnace 2. In other words, when the moisture content of the calcium carbide slag is too low, drying can be achieved solely by the flue gas generated after roasting in the suspension roasting furnace 2, without needing to activate the supplementary heating furnace 5.

[0070] In another embodiment of this disclosure, when the humidity of the carbide slag is greater than a threshold, it is dried by the flue gas generated after roasting in the suspension roasting furnace 2 and the supplementary heating furnace 5. When the humidity is higher than the threshold, the flue gas from the suspension roasting furnace 2 alone is not enough to completely dry the crushed carbide slag. Therefore, it is necessary to combine the hot air from the supplementary heating furnace 5 to dry the crushed carbide slag together.

[0071] In the system disclosed herein, when the moisture content of the calcium carbide slag in the crushing device 4 is high, it can be dried jointly by the flue gas in the suspension roasting furnace 2 and the supplementary heating furnace 5. Furthermore, the power of the supplementary heating furnace 5 is adjustable. Without changing the flue gas flow rate from the suspension roasting furnace 2 to the crushing device 4, adjusting the power of the supplementary heating furnace 5 alone can meet the processing requirements for calcium carbide slag with varying moisture content, further maintaining the stability of the fuel and air supply required by the suspension roasting furnace 2.

[0072] See Figure 2 In one embodiment of this disclosure, the flue gas from the suspension roasting furnace 2 is specifically provided by the first cyclone separator 3. The first cyclone separator 3 is connected to the outlet of the suspension roasting furnace 2. The suspension roasting furnace 2 discharges the roasted solid phase and flue gas together into the first cyclone separator 3. After the first cyclone separator 2 performs gas-solid separation, the separated flue gas has a very high temperature and is discharged from the outlet above the first cyclone separator 2. The outlet of the first cyclone separator 3 is connected to the inlet pipe of the crushing device 4 through a gas pipe, so that the flue gas discharged from the first cyclone separator 3 enters the crushing device 4 to dry the carbide slag in the crushing device 4.

[0073] In one embodiment of this disclosure, see Figure 2It also includes a preheating system, which includes a cyclone preheater 6. The carbide slag crushed by the crushing device 4 is configured to be preheated by the cyclone preheater 6 before entering the suspension roasting furnace 2 for roasting. The crushed carbide slag needs to be preheated before being roasted in the suspension roasting furnace 2.

[0074] In detail, the cyclone preheater 6 can transfer heat from an external heat source to the crushed carbide slag entering the cyclone preheater 6, thereby achieving the purpose of preheating the crushed carbide slag.

[0075] In one embodiment of this disclosure, see Figure 2 The outlet of the first cyclone separator 3 is connected to the inlet of the cyclone preheater 6 through a gas pipeline. The flue gas separated from the first cyclone separator 3 is configured to pass through the cyclone preheater 6 to preheat the carbide slag located in the cyclone preheater 6.

[0076] In one embodiment of this disclosure, see Figure 2 The outlet of the cyclone preheater 6 is connected to the inlet of the crushing device 4 via a gas channel. The flue gas exiting the cyclone preheater 6 preheats the calcium carbide slag, reducing its temperature to a level suitable for drying the calcium carbide slag in the crushing device 4. In other words, the flue gas from the cyclone preheater 6 is configured to enter the crushing device 4 to dry the calcium carbide slag there. Similarly, after drying in the crushing device 4, the calcium carbide slag enters the cyclone preheater 6 for further preheating to increase its preheating temperature until it meets the temperature required for entry into the suspension roasting furnace 6.

[0077] Cyclone preheaters 6 may include at least one or at least two to gradually preheat the carbide slag before it enters the suspension roaster 6 until it meets the standards for entering the suspension roaster 6. Similarly, the flue gas separated by the first cyclone separator 3 may be cooled step by step by these cyclone preheaters 6 until it meets the standards for entering the crushing device 4. This disclosure does not impose a specific limitation on the number of cyclone preheaters 6.

[0078] In the two embodiments described above, see Figure 2 The flue gas enters the first cyclone separator 3 sequentially into the cyclone separator 6 and the crushing device 4, respectively preheating the carbide slag in the cyclone separator 6 and drying the crushed carbide slag in the crushing device 4. The flue gas is high-temperature flue gas generated after roasting in the suspension roasting furnace 2, and the external heat of the cyclone preheater 6 is entirely provided by the high-temperature flue gas.

[0079] In one embodiment of this disclosure, a second cyclone separator 7 is further included. The second cyclone separator 7 is connected between the crushing device 4 and the cyclone preheater 6. The crushed carbide slag and flue gas in the crushing device 4 are fed into the second cyclone separator 7 in the form of a gas-solid mixture. The second cyclone separator 7 separates the gas-solid mixture. The separated solid phase is passed into the cyclone preheater 6 for preheating. The separated flue gas is configured to be discharged from the outlet of the second cyclone separator 7 to the bag filter 8 for collection.

[0080] A baghouse dust collector has an inlet, a filter element, and an outlet. After the flue gas is introduced into the baghouse dust collector, the suspended impurities in the flue gas can be filtered and collected through the filter element, and the filtered flue gas can be discharged through the outlet of the baghouse dust collector.

[0081] In detail, the solid phase after separation is mostly crushed carbide slag, which can be separated from the gas-solid mixture by the second cyclone separator 7; the solid impurities in the separated flue gas are collected by a bag filter, which can avoid direct emission and thus environmental pollution.

[0082] In one embodiment of this disclosure, see Figure 3 The second cyclone separator 7 is connected to the bag filter 101 and also includes an exhaust fan 102 connected to the bag filter. The exhaust fan 102 is configured to send the flue gas in the bag filter 101 into the chimney 103 for discharge.

[0083] In detail, the air inlet of the exhaust fan 102 is connected to the air outlet of the bag filter 101. When the exhaust fan 102 is in operation, it provides negative pressure to the air outlet of the bag filter 101 through the air inlet. This can be understood as the exhaust fan 102 drawing out the filtered flue gas from the bag filter 101. The air outlet of the exhaust fan 102 is connected to the chimney 103, which blows the filtered flue gas out of the chimney 103 to achieve the purpose of emission.

[0084] In the above embodiments, the roasting process of carbide slag by the suspension roasting furnace 2 and the treatment process of carbide slag before roasting have been described in detail. The solid phase entering the cooling system from the suspension roasting furnace 2 is the product after roasting. The cooling, impurity removal and collection process of the product after roasting will be further described below in conjunction with the structure and embodiments of this disclosure.

[0085] See Figure 4 In one embodiment of this disclosure, the cooling system includes at least one stage of cyclone cooler, such as a three-stage cyclone cooler, including a first cyclone cooler 81, a second cyclone cooler 82, and a third cyclone cooler 83. The calcined product will pass through the first cyclone cooler 81, the second cyclone cooler 82, and the third cyclone cooler 83 in sequence, and finally be reduced to the required temperature.

[0086] It should be noted that, in addition to being configured to cool the roasted product step by step, the at least one cyclone cooler is also configured to introduce the hot air generated during the cooling process into the suspension roasting furnace. On the one hand, the hot air flow helps to increase the temperature, and on the other hand, there is no need to add a gas replenishment device to the suspension roasting furnace 2, which reduces the space occupied.

[0087] In detail, the principle of the cyclone cooler is to draw in external air, so that the external air exchanges heat with the roasted product entering the cyclone cooler, thereby reducing the temperature of the roasted product.

[0088] During the cooling process, the external air exchanges heat with the solid phase at high temperature. After passing through the cyclone cooler, the external air exchanges heat with the solid phase and is then heated before entering the suspension roasting furnace to serve as combustion air and auxiliary fuel for combustion.

[0089] For more details, see Figure 4 The discharge port of the first cyclone separator 3 is connected to the inlet of the first cyclone cooler 81. The discharge ports and inlets of the first cyclone cooler 81, the second cyclone cooler 82, and the third cyclone cooler 83 are connected in sequence through pipes so that the solid phase from the first cyclone separator 3 can pass through the first cyclone cooler 81, the second cyclone cooler 82, and the third cyclone cooler 83 in sequence, and be cooled to a suitable temperature in the third cyclone cooler 83 for subsequent processing.

[0090] See Figure 4 The external airflow passes through the three-stage cooler in reverse and finally enters the suspension roasting furnace 2 as combustion air. That is, the outlet and inlet of the third cyclone cooler 83, the second cyclone cooler 82, and the first cyclone cooler 81 are connected in sequence through gas pipes. The external airflow will pass through the third cyclone cooler 83, the second cyclone cooler 82, and the first cyclone cooler 81 in sequence to achieve the purpose of cooling the solid phase.

[0091] For details, see Figure 4 The outlet of the first cyclone cooler 81 is connected to the first air inlet 212 of the suspension roasting furnace 2, providing combustion air to the main combustion zone 21 of the suspension roasting furnace 2; the second cyclone cooler 82 includes two air outlets, one of which is connected to the air inlet of the first cyclone cooler 81, and the other air outlet is connected to the second air inlet 221 of the suspension roasting furnace 2, thereby providing combustion air to the burnout zone 22 of the suspension roasting furnace 2, so that the fuel in the suspension roasting furnace 2 is completely burned.

[0092] Therefore, the external airflow is preheated after passing through at least one cyclone cooler in reverse order. The preheated airflow passes at least partially through the main combustion zone 21 to perform oxygen-deficient roasting of the carbide slag from the raw material silo. At least a portion of the preheated airflow then enters the burnout zone 22, where the carbide slag after oxygen-deficient combustion is roasted. Combustion air is supplied to the suspension roasting furnace 2 through at least one cyclone cooler. This preheated air provides heat to the suspension roasting furnace 2, improving resource utilization.

[0093] In one embodiment of this disclosure, see Figure 5 It also includes a purification device 9, which is connected to the outlet of the third cyclone cooler 83 and is configured to remove impurities from the solid phase cooled by the cyclone cooler 83.

[0094] For details, see Figure 5 The impurity removal device 9 is an air separator, which is configured to screen the solid phase by air separation and blow the screened solid phase into the bag filter 101. The bag filter 101 filters and collects the air-separated solid phase and transports the collected solid phase to the finished product warehouse for storage through a conveying device.

[0095] In one embodiment of this disclosure, see Figure 5 The conveying device includes a conveyor belt 104 and a bucket elevator 105. The conveyor belt 104 is located below the bag filter 101. The solid phase collected by the bag filter 101 is discharged through the discharge port below. The conveyor belt 104 carries the solid phase falling from the bag filter 101 and conveys the solid phase to the bucket elevator 105. The bucket elevator 105 is configured to send the solid phase conveyed by the conveyor belt 104 into the finished product silo 106 for storage.

[0096] Of course, those skilled in the art can also use other methods to transfer the collected solid phase to the finished product warehouse for storage, and there are no restrictions on this.

[0097] In one embodiment of this disclosure, see Figure 5 It also includes an exhaust fan 102 connected to the bag filter 101, the exhaust fan 102 being configured to send the flue gas in the bag filter 101 into the chimney 103 for discharge.

[0098] In detail, when the solid phase enters the impurity removal device 9, some flue gas will also be present. The bag filter 101 can not only filter and collect the solid phase, but also separate and discharge the flue gas. The discharged flue gas is discharged into the chimney 103 through the exhaust fan 102.

[0099] In one embodiment of this disclosure, see Figure 6The raw material silo 1, crushing device 4, cyclone preheater 6, suspension roasting furnace 2, cooling system, and impurity removal device 9 are connected in sequence to achieve the preparation of solid phase from carbide slag. Therefore, the carbide slag will be crushed, preheated, roasted, cooled, and impurity removed in sequence to finally obtain a solid phase product that meets the requirements. The solid phase product can be activated calcium oxide, overburned calcium oxide, etc. prepared by carbide slag.

[0100] It should be noted that the connection relationship, structure and function of all devices in this embodiment are the same as those in the above embodiments. The function of each device in this embodiment can be completely deduced from the description in the above embodiments.

[0101] The system disclosed herein performs powder selection and impurity removal on the calcined finished product. Since the material has already been decomposed, the load of powder selection and impurity removal is reduced, saving investment and operating costs. At the same time, it avoids the problem of material agglomeration and clumping during impurity removal before calcination, which would cause more qualified material to be removed along with impurities, resulting in a decrease in the yield of qualified products.

[0102] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein. The scope of this disclosure is defined by the appended claims.

Claims

1. A calcium carbide sludge suspension calcination system, characterized by, The application relates to a calcium carbide residue roasting system, which comprises: a raw material bin; a suspension roaster, which comprises a main combustion zone and a burnout zone located above the main combustion zone along the extension direction of the suspension roaster; the main combustion zone comprises a first air inlet configured to introduce insufficient combustion air into the main combustion zone to perform under-oxygen roasting of calcium carbide residue from the raw material bin in the main combustion zone; the burnout zone comprises a second air inlet configured to introduce combustion air capable of completely burning fuel into the burnout zone to perform roasting of the calcium carbide residue after under-oxygen roasting in the main combustion zone in the burnout zone; a first cyclone separator configured to communicate with the outlet of the suspension roaster to perform gas-solid separation; the separated solid phase is configured to be fed into the suspension roaster in a proportionally adjustable manner to perform repeated roasting, and be fed into a cooling system to form active calcium oxide or over-burned calcium oxide by adjusting the circulation ratio.

2. The calcium carbide sludge suspension calcination system according to claim 1, characterized in that, The suspension roaster further comprises a burner extending into the main combustion zone, and the burnout zone is configured to be arranged at a predetermined height position away from the burner.

3. The calcium carbide sludge suspension calcination system according to claim 1, characterized in that, The cooling system comprises at least one stage of cyclone coolers, and the solid phase from the first cyclone separator is sequentially fed into the at least one stage of cyclone coolers to be cooled.

4. The calcium carbide sludge suspension calcination system according to claim 3, characterized in that, The external airflow is reversely sequentially passed through the at least one stage of cyclone coolers to be preheated, and the preheated airflow is at least partially introduced into the main combustion zone to perform under-oxygen roasting of the calcium carbide residue from the raw material bin in the main combustion zone.

5. The calcium carbide sludge suspension calcination system of claim 4, wherein, The preheated airflow is at least partially introduced into the burnout zone to perform roasting of the under-oxygen roasted calcium carbide residue in the burnout zone.

6. The calcium carbide sludge suspension calcination system of claim 4, wherein, The cyclone coolers comprise a first cyclone cooler, a second cyclone cooler and a third cyclone cooler which are sequentially communicated; the solid phase sequentially passes through the first cyclone cooler, the second cyclone cooler and the third cyclone cooler to be cooled, and the external airflow is reversely sequentially passed through the third cyclone cooler, the second cyclone cooler and the first cyclone cooler to be preheated.

7. The calcium carbide sludge suspension calcination system of claim 4, wherein, The application further comprises a dedusting device, and the solid phase cooled by the cyclone coolers is configured to be subjected to dedusting in the dedusting device.

8. The calcium carbide sludge suspension calcination system of claim 7, wherein, The dedusting device is an air separator configured to screen the solid phase by air separation, and the screened finished product is configured to be introduced into a finished product bin through a bag-type dust collector.

9. The calcium carbide sludge suspension calcination system of claim 3, wherein, The application further comprises a crushing device, and the calcium carbide residue in the raw material bin is crushed by the crushing device and then fed into the suspension roaster to be roasted.

10. The calcium carbide sludge suspension calcination system of claim 9, wherein, The application further comprises a preheating system, and the preheating system comprises at least one stage of cyclone preheaters; the calcium carbide residue crushed by the crushing device is configured to be preheated by the at least one stage of cyclone preheaters and then introduced into the suspension roaster to be roasted.

11. The calcium carbide sludge suspension calcination system of claim 10, wherein, The flue gas separated from the cyclone separator is configured to pass through the cyclone preheaters to preheat the calcium carbide residue located in the cyclone preheaters.

12. The calcium carbide sludge suspension calcination system of claim 11, wherein, The flue gas from the cyclone preheaters is configured to be introduced into the crushing device to dry the calcium carbide residue in the crushing device.

13. The calcium carbide sludge suspension calcination system of claim 12, wherein, The second cyclone separator is further included, and the dried carbide slag in the crushing device is configured to perform gas-solid separation in the second cyclone separator; the separated solid phase enters the cyclone preheater for preheating; and the separated flue gas is configured to pass through the bag-type dust collector for collection.

14. The calcium carbide sludge suspension calcination system of claim 12, wherein, The heat supplementing furnace is further included, and the heat supplementing furnace is configured to adjustably dry the carbide slag in the crushing device.

15. The calcium carbide sludge suspension calcination system of claim 1, wherein, The adjusting device is further included, and the adjusting device is configured to adjust the proportion of the solid phase entering the suspension roaster for repeated roasting and entering the cooling system for cooling.

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