Acid making device and method

Abstract

The invention discloses an acid making device and method, and relates to the technical field of acid making. The first waste heat boiler is communicated with the main incinerator; the expansion incinerator is communicated with the main incinerator; and the second waste heat boiler is communicated with the expansion incinerator. When the coking waste salt feeding amount in the main incinerator does not exceed the preset load of the main incinerator, the coking waste salt is incinerated by means of the main incinerator; when the feeding amount of the coking waste salt in the main incinerator is higher than the preset load of the main incinerator, the coking waste which is not treated in the main incinerator is fed into the expanding incinerator, and the expanding incinerator can incinerate the coking waste in the main incinerator again; and only when the coking waste salt amount exceeds the main incinerator, the expansion incinerator needs to be started, the requirement for the preset load needed by the main incinerator and the expansion incinerator is reduced, and the problem that the cost is relatively high is solved on the whole.

Description

Technical Field

[0001] The present invention relates to the technical field of acid production, and in particular to an acid production device and method. Background Art

[0002] Incineration of waste salt to produce acid is an important way to treat and recycle coking desulfurization waste liquid. This process burns coking waste salt in an incinerator to produce high-concentration sulfur dioxide flue gas, and then passes the high-concentration sulfur dioxide flue gas into the waste heat boiler.

[0003] Coking waste salt is a common sulfur-containing waste salt. Coking waste salt is a by-product of coking production. The output of coking waste salt will vary with the sulfur content of the coal used in the coking plant and the coke output. In order to ensure that all waste salt can be quickly processed after it is produced, two sets of incineration and waste heat recovery devices with different capacities are designed to switch between each other to meet the requirements of load adjustment, and the cost is relatively high. Summary of the invention

[0004] The main purpose of the present invention is to provide an acid production device and method, aiming to improve the problem of relatively high cost.

[0005] To achieve the above-mentioned purpose, the acid-making device proposed in the present invention has a main incinerator, which has a first inlet, a combustion-supporting gas inlet, a first outlet, and a second outlet. The first inlet is used to introduce sulfur-containing waste salt, the first outlet is provided with a first gate, and the second outlet is provided with a second gate;

[0006] a first waste heat boiler having a second inlet, the second inlet being connected to the first outlet, and a preset load of the first waste heat boiler matching a preset load of the main incinerator;

[0007] An expanded incinerator having a third inlet and a third outlet, wherein the third inlet is connected to the second outlet, and the third outlet is provided with a third damper; and

[0008] The second waste heat boiler has a fourth inlet, which is connected to the third outlet. The preset load of the second waste heat boiler matches the sum of the preset load of the main incinerator and the preset load of the expansion incinerator.

[0009] In one embodiment, the main incinerator is provided with a first thermometer, and the first thermometer is used to detect the temperature of the flue gas outlet of the main incinerator; and / or,

[0010] The first waste heat boiler is provided with a second thermometer, and the second thermometer is used to detect the temperature of the flue gas outlet of the first waste heat boiler.

[0011] In one embodiment, a third thermometer is provided on the second waste heat boiler, and the third thermometer is used to detect the flue gas outlet of the second waste heat boiler.

[0012] The present invention also provides an acid production method, based on the acid production device, the acid production device has a low load mode and a high load mode;

[0013] When the amount of coking waste salt fed into the first inlet is higher than the preset load of the main incinerator, switching the acid-making device to a high-load mode;

[0014] When the amount of coking waste salt from the first inlet is not higher than the preset load of the main incinerator, the acid-making device is switched to a low-load mode.

[0015] In one embodiment, switching the acid-making plant to a low-load mode comprises:

[0016] Open the first gate, close the second gate, and start the main incinerator and the first waste heat boiler;

[0017] The flue gas generated in the main incinerator is fed into the first waste heat boiler to switch the acid-making device to a low-load mode.

[0018] In one embodiment, the acid production method further includes: when at least one of the expansion incinerator and the second waste heat boiler fails, placing the acid production device in a low load mode to repair the failed expansion incinerator and / or the second waste heat boiler.

[0019] In one embodiment, switching the acid-making plant to a high load mode comprises:

[0020] The first gate is closed, the second gate and the third gate are opened, and the main incinerator, the expansion incinerator and the second waste heat boiler are started;

[0021] The unreacted coking waste salt in the main incinerator is fed into the expansion incinerator, the flue gas generated in the main incinerator is fed into the expansion incinerator, and the flue gas in the expansion incinerator is fed into the second waste heat boiler to switch the acid-making device to a high-load mode.

[0022] In one embodiment, the acid production method further comprises:

[0023] When the first waste heat boiler fails, the acid-making plant is placed in a high-load mode to repair the first waste heat boiler.

[0024] In one embodiment, when the acid-making device is in low-load mode, and the temperature of the flue gas in the main incinerator is higher than a first preset temperature, and / or the flue gas outlet temperature of the first waste heat boiler is higher than a second preset temperature; the acid-making device is switched to high-load mode.

[0025] In one embodiment, when the acid-making device is in a high-load mode and the flue gas outlet temperature of the second waste heat boiler is lower than a third preset temperature, the acid-making device is switched to a low-load mode.

[0026] The technical solution of the present invention is to set a main incinerator, a first waste heat boiler, an expansion incinerator and a second waste heat boiler. When the amount of coking waste salt in the main incinerator does not exceed the preset load of the main incinerator, the coking waste salt is incinerated with the help of the main incinerator, and then the flue gas generated by the incineration in the main incinerator is sent to the first waste heat boiler; when the amount of coking waste salt in the main incinerator is higher than the preset load of the main incinerator, the untreated coking waste in the main incinerator is sent to the expansion incinerator, and the expansion incinerator can incinerate the coking waste in the main incinerator again, and send the flue gas generated in the main incinerator and the expansion incinerator to the second waste heat boiler, which is conducive to achieving sufficient treatment of the coking waste salt; the expansion incinerator only needs to be started when the amount of coking waste salt exceeds that of the main incinerator, thereby reducing the demand for preset loads required for the main incinerator and the expansion incinerator, and there is no need to separately set up an incinerator with a larger preset load, thereby reducing costs and improving the problem of relatively high costs as a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0028] Figure 1 This is a schematic structural diagram of an acid-making device according to an embodiment of the present invention.

[0029] Description of Figure Numbers:

[0030] 100. Acid-making device; 1. Main incinerator; 11. First inlet; 12. Combustion-supporting gas inlet; 13. First outlet; 14. Second outlet; 2. First waste heat boiler; 21. Second inlet; 3. Expansion incinerator; 31. Third inlet; 32. Third outlet; 4. Second waste heat boiler; 41. Fourth inlet; 5. First gate; 6. Second gate; 7. Third gate.

[0031] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0034] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] Incineration of waste salt to produce acid is an important way to treat and recycle coking desulfurization waste liquid. This process burns coking waste salt in an incinerator to produce high-concentration sulfur dioxide flue gas, and then passes the high-concentration sulfur dioxide flue gas into the waste heat boiler.

[0036] Coking waste salt is sulfur-containing waste salt. It is a by-product of coking production. The output of coking waste salt will vary with the sulfur content of the coal used in the coking plant and the coke output. In order to ensure that all waste salt can be quickly processed after it is produced, two sets of devices with different incineration and waste heat recovery capabilities are designed to switch between each other to meet the requirements of load adjustment. The preset loads of the two incinerators are different. The preset load of one incinerator is higher, and the preset load of the other incinerator is relatively low, and the cost is relatively high. When one incinerator is working, the other incinerator is in a stopped state. According to the different amounts of coking waste salt to be processed, the incinerator needs to be switched first so that the corresponding incinerator can incinerate the coking waste salt. The incineration route is costly, difficult, time-consuming, and difficult to accurately control.

[0037] The invention provides an acid-making device.

[0038] See also Figure 1 In one embodiment of the present invention, the acid-making device 100 comprises:

[0039] The main incinerator 1 has a first inlet 11, a combustion-supporting gas inlet 12, a first outlet 13 and a second outlet 14. The first inlet 11 is used to introduce sulfur-containing waste salt. The first outlet 13 is provided with a first gate 5. The second outlet 14 is provided with a second gate 6.

[0040] The first waste heat boiler 2 has a second inlet 21, the second inlet 21 is connected to the first outlet 13, and the preset load of the first waste heat boiler 2 matches the preset load of the main incinerator 1;

[0041] The expanded incinerator 3 has a third inlet 31 and a third outlet 32, wherein the third inlet 31 is connected to the second outlet 14, and the third outlet 32 ​​is provided with a third damper 7; and,

[0042] The second waste heat boiler 4 has a fourth inlet 41 , which is connected to the third outlet 32 ​​. The preset load of the second waste heat boiler 4 matches the sum of the preset load of the main incinerator 1 and the preset load of the expansion incinerator 3 .

[0043] The technical solution of the present invention is to set up a main incinerator 1, a first waste heat boiler 2, an expansion incinerator 3 and a second waste heat boiler 4. When the amount of coking waste salt in the main incinerator 1 does not exceed the preset load of the main incinerator 1, the coking waste salt is incinerated by means of the main incinerator 1, and then the flue gas generated by the incineration of the main incinerator 1 is sent to the first waste heat boiler 2; when the amount of coking waste salt in the main incinerator 1 is higher than the preset load of the main incinerator 1, the untreated coking waste in the main incinerator 1 is sent to the second waste heat boiler 4. In the expansion incinerator 3, the expansion incinerator 3 can re-incinerate the coking waste in the main incinerator 1, and send the flue gas generated in the main incinerator 1 and the expansion incinerator 3 to the second waste heat boiler 4, which is conducive to the full treatment of the coking waste salt; the expansion incinerator 3 only needs to be started when the amount of coking waste salt exceeds that of the main incinerator 1, which reduces the demand for preset loads required by the main incinerator 1 and the expansion incinerator 3, and does not need to set up a separate incinerator with a larger preset load, thereby reducing costs and improving the problem of relatively high costs as a whole.

[0044] See also Figure 1 By controlling the first gate plate 5, the on / off of the main incinerator 1 and the first waste heat boiler 2 can be controlled; by controlling the second gate plate 6, the on / off of the main incinerator 1 and the expansion incinerator 3 can be controlled; by controlling the third gate plate 7, the on / off of the expansion incinerator 3 and the second waste heat boiler 4 can be controlled.

[0045] The combustion-supporting gas is mostly air, which is fed into the main incinerator 1 through the combustion-supporting gas inlet 12, thereby supporting the combustion of the coking waste salt in the main incinerator 1. The combustion-supporting gas can enter the expansion incinerator 3 through the second outlet 14, thereby supporting the combustion of the coking waste salt in the expansion incinerator 3.

[0046] See also Figure 1In the embodiment of the present application, the preset load of the main incinerator 1 is 28 tons of coking waste salt, and the preset load of the main incinerator 1 is the rated processing capacity of coking waste salt per unit time. When the main incinerator 1 processes the coking waste salt within its preset load, the main incinerator 1 can fully incinerate the coking waste salt, and the temperature of the sulfur-containing flue gas generated by the main incinerator 1 is not higher than 1100°C. After the flue gas generated by the main incinerator 1 is introduced into the first waste heat boiler 2, the first waste heat boiler 2 cools the flue gas generated in the main incinerator 1 so that the temperature of the flue gas drops to the target temperature. When the amount of coking waste salt in the main incinerator 1 is higher than the preset load of the main incinerator 1, it is difficult for the main incinerator 1 to fully incinerate the coking waste salt, and the flue gas generated by the main incinerator 1 is higher than the processing capacity of the first waste heat boiler 2. After the first waste heat boiler 2 processes the flue gas, the temperature of the flue gas after cooling by the first waste heat boiler 2 is higher than the target temperature, and it is difficult to fully cool the flue gas.

[0047] The main incinerator 1 is provided with a first thermometer, which is used to detect the temperature of the flue gas outlet of the main incinerator 1. By setting the first thermometer to detect the temperature of the flue gas generated by the main incinerator 1, when the temperature of the flue gas generated by the main incinerator 1 is higher than 1100°C, the discharge amount of the flue gas generated in the main incinerator 1 is higher than the preset load of the first waste heat boiler 2, and it can be known that the amount of coking waste salt in the main incinerator 1 is higher than the preset load of the main incinerator 1.

[0048] The first thermometer can be set according to the structure and actual working conditions of the main incinerator 1. The preset temperature of the first thermometer can be set according to the installation position of the first thermometer. In the embodiment of the present application, the preset temperature of the first thermometer is 1100°C.

[0049] The first waste heat boiler 2 is provided with a second thermometer, and the second thermometer is used to detect the temperature of the flue gas outlet of the first waste heat boiler 2. The temperature of the flue gas treated by the first waste heat boiler 2 can be detected by means of the second thermometer to determine whether the first waste heat boiler 2 has reduced the flue gas to the target temperature. When the temperature of the flue gas treated by the first waste heat boiler 2 is higher than the preset temperature of the second thermometer, it can be determined that the flue gas intake of the first waste heat boiler 2 is higher than the target treatment amount of the first waste heat boiler 2, that is, the intake of the first waste heat boiler 2 is higher than the preset load of the first waste heat boiler 2, and it can be known that the amount of coking waste salt in the main incinerator 1 is higher than the preset load of the main incinerator 1.

[0050] The first gate 5, the second gate 6 and the third gate 7 can be set to be automatically controlled or manually controlled.

[0051] When the amount of coking waste salt in the main incinerator 1 is greater than that of the main incinerator 1, the flue gas output of the main incinerator 1 will be higher than the flue gas processing capacity of the expansion incinerator 3, and the flue gas in the main incinerator 1 is difficult to be normally sent to the first waste heat boiler 2, and the flue gas is easy to gather and heat up in the main incinerator 1.

[0052] The main incinerator 1 is provided with a first thermometer, which is used to detect the temperature of the flue gas outlet of the main incinerator 1; the first waste heat boiler 2 is provided with a second thermometer, which is used to detect the temperature of the flue gas outlet of the first waste heat boiler 2. The first thermometer and the second thermometer cooperate to detect the temperature of the flue gas outlet of the main incinerator 1 and the temperature of the flue gas outlet of the first waste heat boiler 2 at the same time.

[0053] The second waste heat boiler 4 is provided with a third thermometer, and the third thermometer is used to detect the flue gas outlet of the second waste heat boiler 4. When the main incinerator 1 and the expansion incinerator 3 are started, when the intake of the coking waste salt of the main incinerator 1 is lower than the preset load of the main incinerator 1, the flue gas outlet of the expansion incinerator 3 will be lower than the preset load of the second waste heat boiler 4, and the second waste heat boiler 4 will cool the temperature of the flue gas to below the target temperature. When the detection temperature of the third thermometer is lower than the preset temperature of the third thermometer, it can be known that the intake of the second waste heat boiler 4 is lower than the preset load of the second waste heat boiler 4, and the flue gas with too low temperature is easy to cause low-temperature corrosion to the second waste heat boiler 4. By shutting down the expansion incinerator 3 and the second waste heat boiler 4, the main incinerator 1 can process the coking waste salt alone, and the flue gas generated by the main incinerator 1 is passed into the first waste heat boiler 2, reducing the low-temperature corrosion caused by the flue gas after cooling.

[0054] The installation position of the third thermometer may be the flue gas outlet of the second waste heat boiler 4, and the preset temperature of the third thermometer is 450°C.

[0055] The present invention also proposes an acid production method, which is used in an acid production device 100. The specific structure of the acid production device 100 refers to the above embodiment. Since the acid production method adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here. The acid production device 100 has a low load mode and a high load mode;

[0056] See also Figure 1 , when the amount of coking waste salt fed into the first inlet 11 is higher than the preset load of the main incinerator 1, the acid-making device 100 is switched to a high-load mode;

[0057] When the amount of coking waste salt fed to the first inlet 11 is not higher than the preset load of the main incinerator 1 , the acid-making device 100 is switched to a low-load mode.

[0058] When the amount of coking waste salt is not higher than the preset load of the main incinerator 1, when the acid-making device 100 is switched to the low-load mode, the intensity of the incineration of the coking waste salt can be reduced, the cost of incineration of the coking waste salt can be reduced, and the low-temperature corrosion caused by flue gas cooling can be reduced, thereby reducing the cost of acid production. When the amount of coking waste salt is higher than the preset load of the main incinerator 1, the acid-making device 100 is switched to the high-load mode to ensure sufficient treatment of the coking waste salt.

[0059] Specifically, switching the acid-making device 100 to the low-load mode includes: opening the first gate 5, closing the second gate 6, and starting the main incinerator 1 and the first waste heat boiler 2; sending the flue gas generated in the main incinerator 1 into the first waste heat boiler 2, so as to switch the acid-making device 100 to the low-load mode. In the low-load mode, the expansion incinerator 3 and the second waste heat boiler 4 are in a closed state, and the coking waste salt is only incinerated by the main incinerator 1, and the flue gas is processed by the first waste heat boiler 2, thereby reducing the cost of incinerating the coking waste salt.

[0060] See also Figure 1 The acid-making method further includes: when at least one of the expansion incinerator 3 and the second waste heat boiler 4 fails, the acid-making device 100 is placed in a low-load mode to repair the failed expansion incinerator 3 and / or the second waste heat boiler 4. In the low-load mode, the expansion incinerator 3 and the second waste heat boiler 4 are shut down, which can ensure the treatment of the coking waste salt while repairing the expansion incinerator 3 and the second waste heat boiler 4.

[0061] Specifically, the acid-making device 100 is switched to the high-load mode, including: closing the first gate 5, opening the second gate 6 and the third gate 7, starting the main incinerator 1, the expansion incinerator 3 and the second waste heat boiler 4; sending the unreacted coking waste salt in the main incinerator 1 to the expansion incinerator 3, sending the flue gas generated in the main incinerator 1 to the expansion incinerator 3, and sending the flue gas in the expansion incinerator 3 to the second waste heat boiler 4, so as to switch the acid-making device 100 to the high-load mode. In the high-load mode, the first waste heat boiler 2 is closed, the main incinerator 1 and the expansion incinerator 3 cooperate to ensure the full incineration of the coking waste salt, the flue gas output of the expansion incinerator 3 can meet the demand of the second waste heat boiler 4, and the second waste heat boiler 4 can ensure the cooling of the flue gas.

[0062] The acid-making method further includes: when the first waste heat boiler 2 fails, the acid-making device 100 is placed in a high-load mode to repair the first waste heat boiler 2. In the high-load state, the first waste heat boiler 2 does not process the flue gas, that is, the first waste heat boiler 2 is in a closed state, and the main incinerator 1, the expansion incinerator 3 and the second waste heat boiler 4 can ensure the processing of coking waste salt; while processing the coking waste salt, it is convenient to repair the first waste heat boiler 2.

[0063] When the acid-making device 100 is in the low-load mode and the temperature of the flue gas in the main incinerator 1 is higher than the first preset temperature, the acid-making device 100 is switched to the high-load mode.

[0064] When the flue gas outlet temperature of the first waste heat boiler 2 is higher than the second preset temperature, the acid-making device 100 is switched to a high load mode.

[0065] When the acid-making device 100 is in low-load mode, and the temperature of the flue gas in the main incinerator 1 is higher than the first preset temperature, and the flue gas outlet temperature of the first waste heat boiler 2 is higher than the second preset temperature; the acid-making device 100 is switched to high-load mode. When the processing efficiency of the main incinerator 1 decreases, or the sulfur content of the coking waste salt increases, the sulfur content of the coking waste salt exceeds the preset load of the main incinerator 1, so that the flue gas in the main incinerator 1 increases, and the temperature of the flue gas in the main incinerator 1 increases. By switching the acid-making device 100 to high-load mode, the coking waste salt can be fully burned.

[0066] When the acid-making device 100 is in high-load mode and the flue gas outlet temperature of the second waste heat boiler 4 is lower than the third preset temperature, the acid-making device 100 is switched to low-load mode. When the flue gas outlet temperature of the second waste heat boiler 4 is lower than the third preset temperature, it can be known that the flue gas flowing out of the expansion incinerator 3 is lower than the processing load of the second waste heat boiler 4. By switching the acid-making device 100 to low-load mode, the low-temperature corrosion of the second waste heat boiler 4 caused by the low flue gas temperature can be reduced.

[0067] In the embodiment of the present application, the first preset temperature is related to the installation position of the first thermometer, the second preset temperature is related to the installation position of the second thermometer, and the third preset temperature is related to the installation position of the third thermometer.

[0068] The installation position of the first thermometer is preferably the first outlet 13 of the main incinerator 1, the preset temperature of the first thermometer is preferably 1100°C, the installation position of the second thermometer is preferably the flue gas outlet of the first waste heat boiler 2, and the second preset temperature is preferably 550°C; the installation position of the third thermometer is preferably the flue gas outlet of the second waste heat boiler 4, and the third preset temperature is pre-selected at 450°C.

[0069] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An acid-making device, characterized in that: include: A main incinerator has a first inlet, a combustion-supporting gas inlet, a first outlet, and a second outlet, wherein the first inlet is used to introduce sulfur-containing waste salt, the first outlet is provided with a first gate, and the second outlet is provided with a second gate; a first waste heat boiler having a second inlet, the second inlet being connected to the first outlet, and a preset load of the first waste heat boiler matching a preset load of the main incinerator; An expanded incinerator having a third inlet and a third outlet, wherein the third inlet is connected to the second outlet, and the third outlet is provided with a third damper; and The second waste heat boiler has a fourth inlet, which is connected to the third outlet. The preset load of the second waste heat boiler matches the sum of the preset load of the main incinerator and the preset load of the expansion incinerator.

2. The acid-making device according to claim 1, characterized in that: The main incinerator is provided with a first thermometer, and the first thermometer is used to detect the temperature of the flue gas outlet of the main incinerator; and / or, The first waste heat boiler is provided with a second thermometer, and the second thermometer is used to detect the temperature of the flue gas outlet of the first waste heat boiler.

3. The acid production device according to claim 1, characterized in that: The second waste heat boiler is provided with a third thermometer, and the third thermometer is used to detect the flue gas outlet of the second waste heat boiler.

4. A method for producing acid, based on the acid producing device according to any one of claims 1 to 3, characterized in that: The acid-making device has a low-load mode and a high-load mode; When the amount of coking waste salt fed into the first inlet is higher than the preset load of the main incinerator, switching the acid-making device to a high-load mode; When the amount of coking waste salt fed to the first inlet is not higher than the preset load of the main incinerator, the acid-making device is switched to a low-load mode.

5. The method for producing acid according to claim 4, characterized in that: Switching the acid-making unit to a low-load mode includes: Open the first gate, close the second gate, and start the main incinerator and the first waste heat boiler; The flue gas generated in the main incinerator is fed into the first waste heat boiler to switch the acid-making device to a low-load mode.

6. The method for producing acid according to claim 5, characterized in that: The acid-making method further includes: when at least one of the expansion incinerator and the second waste heat boiler fails, placing the acid-making device in a low-load mode to repair the failed expansion incinerator and / or the second waste heat boiler.

7. The method for producing acid according to claim 4, characterized in that: Switching the acid-making unit to a high-load mode includes: The first gate is closed, the second gate and the third gate are opened, and the main incinerator, the expansion incinerator and the second waste heat boiler are started; The unreacted coking waste salt in the main incinerator is fed into the expansion incinerator, the flue gas generated in the main incinerator is fed into the expansion incinerator, and the flue gas in the expansion incinerator is fed into the second waste heat boiler to switch the acid-making device to a high-load mode.

8. The method for producing acid according to claim 7, characterized in that: The acid production method further comprises: When the first waste heat boiler fails, the acid-making plant is placed in a high-load mode to repair the first waste heat boiler.

9. The method for producing acid according to claim 4, characterized in that: When the acid-making device is in low-load mode, and the temperature of the flue gas in the main incinerator is higher than a first preset temperature, and / or the flue gas outlet temperature of the first waste heat boiler is higher than a second preset temperature; the acid-making device is switched to high-load mode.

10. The method for producing acid according to claim 4, characterized in that: When the acid-making device is in a high-load mode and the flue gas outlet temperature of the second waste heat boiler is lower than a third preset temperature, the acid-making device is switched to a low-load mode.

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