Sulfuric acid conveying system with multi-source switching function and control method

Abstract

The invention relates to a sulfuric acid conveying system with a multi-source switching function and a control method. According to the sulfuric acid conveying system, a self-produced sulfuric acid conveying system and an outsourced sulfuric acid conveying system are connected with a sulfuric acid overhead tank and a mother liquor full-flow tank, so that the conveying systems are combined, and a substitute interchange optimization function is added; continuous production in the maintenance period of system equipment components is guaranteed, manual operation is replaced, the sulfur content of coal gas is prevented from exceeding the standard, safety of operators is ensured, multidirectivity and complementarity of the sulfuric acid conveying system are achieved, unicity of an original conveying system is made up, waste heat continuous operation stability of the sulfuric acid conveying system is guaranteed, and production efficiency is improved. The stability of a production system and a use system is improved, and the effect that one pipe has multiple purposes is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal gas purification and desulfurization, and more particularly to a sulfuric acid delivery system with multi-source switching function and a control method. BACKGROUND

[0002] In the steel industry, the coal gas purification process is designed to match the coking production capacity. The desulfurization coal gas purification system generates concentrated sulfuric acid by absorbing and reacting sulfur dioxide in the coal gas. The concentrated sulfuric acid is used as an acidic mother liquor supplement for the production of ammonium sulfate in the saturator. The concentrated sulfuric acid in the acidic mother liquor is sourced from self-production and purchase. Ammonium sulfate is generated by absorbing and reacting ammonia in the coal gas. When the amount of self-produced concentrated sulfuric acid cannot meet the long-term needs of the ammonium sulfate production system, it is necessary to purchase concentrated sulfuric acid to effectively remove ammonia from the coal gas. Therefore, under normal circumstances, the coal gas purification system includes a self-produced concentrated sulfuric acid delivery system and a purchased concentrated sulfuric acid delivery system. The self-produced or purchased concentrated sulfuric acid is delivered to the sulfuric acid high tank of the saturator production process. However, the self-produced concentrated sulfuric acid delivery system and the purchased concentrated sulfuric acid delivery system have single delivery functions and cannot be used interchangeably. In addition, when the saturator production equipment is being maintained and repaired, such as the sulfuric acid high tank, it is not possible to supplement concentrated sulfuric acid to the system, which leads to incomplete removal of ammonia from the coal gas, affects the coal gas purification effect of the subsequent process and the service life of the equipment, and most seriously, the coal gas purification and desulfurization system is prone to environmental accidents caused by the deterioration of the desulfurization circulating liquid due to excessive ammonia content in the coal gas. Based on this, the present application proposes an improved sulfuric acid delivery device and control method to solve the above problems. SUMMARY

[0003] In view of the deficiencies of the prior art, the present application aims to provide a sulfuric acid delivery system with multi-source switching function and a control method. The self-produced sulfuric acid delivery system and the purchased sulfuric acid delivery system are connected with the sulfuric acid high tank and the mother liquor full-flow tank, the delivery systems are combined and an alternative exchange optimization function is added, ensuring continuous production and alternative manual operation during maintenance of system equipment components, preventing excessive sulfur in coal gas and ensuring the safety of workers, achieving the multi-directionality and complementarity of the sulfuric acid delivery system, making up for the singleness of the original delivery system, ensuring the continuous operation stability of the sulfuric acid delivery system waste heat, improving the stability of the production system and the use system, and realizing the function of one pipe with multiple purposes.

[0004] The above technical purpose of the present application is achieved by the following technical scheme: A sulfuric acid delivery system with multi-source switching function, comprising a sulfuric acid high tank, a mother liquor full-flow tank, and a self-produced sulfuric acid delivery system and a purchased sulfuric acid delivery system. The sulfuric acid high tank is connected with the mother liquor full-flow tank through a first pipeline. An acid outlet valve and an acid inlet full-flow tank valve are arranged on the first pipeline. The acid outlet valve is located upstream of the acid inlet full-flow tank valve. The purchased sulfuric acid delivery system includes an oil depot sulfuric acid storage tank and a sulfuric acid delivery pump. The oil depot sulfuric acid storage tank is connected to the sulfuric acid high-level tank through a second pipeline. The sulfuric acid delivery pump is installed on the second pipeline. The upstream of the sulfuric acid delivery pump is equipped with a first pump inlet valve, the downstream of the sulfuric acid delivery pump is equipped with a first pump outlet valve, and the downstream output end of the second pipeline is equipped with a first acid tank inlet valve. The self-produced sulfuric acid delivery system includes an acid production unit, an intermediate acid tank, and an acid product pump. The acid production unit is connected to the intermediate acid tank via a third pipeline. The intermediate acid tank is connected to the sulfuric acid elevated tank via a fourth pipeline. The acid product pump is installed on the fourth pipeline. A second pump inlet valve is installed upstream of the acid product pump, a second pump outlet valve is installed downstream of the acid product pump, and a second acid tank inlet valve is installed at the downstream output end of the fourth pipeline. The second pipeline and the fourth pipeline are connected through the first connecting pipeline. A switching valve is installed on the first connecting pipeline. The connection point between the first connecting pipeline and the second pipeline is located between the first acid tank inlet valve and the first pump outlet valve. The connection point between the first connecting pipeline and the fourth pipeline is located between the second acid tank inlet valve and the second pump outlet valve. The first pipeline and the fourth pipeline are connected by a second connecting pipeline. The second connecting pipeline is equipped with a self-generated acid inlet full flow tank valve. The connection point between the second connecting pipeline and the first pipeline is located between the acid outlet valve and the acid inlet full flow tank valve. The connection point between the second connecting pipeline and the fourth pipeline is located downstream of the second pump outlet valve. Liquid level sensors are installed in the acid intermediate tank, sulfuric acid high-level tank, and sulfuric acid storage tank in the oil depot to monitor the liquid level in the tank.

[0005] In one embodiment, a first reflux pipe is provided between the second pipe and the sulfuric acid storage tank of the oil depot. A pump reflux valve is provided on the first reflux pipe. The connection point between the first reflux pipe and the second pipe is located between the inlet valve of the first acid tank and the outlet valve of the first pump.

[0006] In one embodiment, a second reflux pipe is provided between the fourth pipe and the acid intermediate tank, and an acid tank injection valve is provided on the second reflux pipe. The connection point between the second reflux pipe and the fourth pipe is between the second acid tank inlet valve and the second pump outlet valve.

[0007] In one embodiment, a third reflux pipe is provided between the third pipe and the fourth pipe, and an acid reflux valve is provided on the third reflux pipe. The connection point between the third reflux pipe and the fourth pipe is located between the acid product pump and the outlet valve of the second pump.

[0008] In one embodiment, an acid cooler is also provided on the third return pipe, which is located upstream of the acid return valve.

[0009] A control method for a sulfuric acid delivery system with multi-source switching capability is as follows: When the sulfuric acid high-level tank and acid production unit are both in normal condition: If the liquid level height in the high-positioned sulfuric acid tank is < 40%, it indicates that the self-produced sulfuric acid is insufficient, and the purchased sulfuric acid delivery system is started to deliver sulfuric acid to the high-positioned sulfuric acid tank; If the liquid level height in the high-positioned sulfuric acid tank is > 90%, it indicates that the self-produced sulfuric acid is excessive, and the purchased sulfuric acid delivery system is stopped to deliver sulfuric acid to the high-positioned sulfuric acid tank, the switching valve between the self-produced sulfuric acid delivery system and the purchased sulfuric acid delivery system is opened, and the pump backflow valve in the purchased sulfuric acid delivery system is opened, and part of the sulfuric acid from the self-produced sulfuric acid delivery system flows into the oil depot sulfuric acid storage tank for storage; If the liquid level height in the high-positioned sulfuric acid tank is ≥ 95%, the self-produced sulfuric acid delivery system is stopped to deliver sulfuric acid to the high-positioned sulfuric acid tank, the switching valve between the self-produced sulfuric acid delivery system and the purchased sulfuric acid delivery system is opened, and the pump backflow valve in the purchased sulfuric acid delivery system is opened, and all of the sulfuric acid from the self-produced sulfuric acid delivery system flows into the oil depot sulfuric acid storage tank for storage.

[0010] In one of the embodiments, when the high-positioned sulfuric acid tank is in a maintenance state and the acid production device is in a normal state: The first acid tank inlet valve, the second acid tank inlet valve, and the acid outlet valve are closed, the self-produced acid inlet full-flow tank valve is opened, and the self-produced acid inlet full-flow tank valve is kept in an open state, the self-produced sulfuric acid delivery system is used to preferentially supply acid to the mother liquor full-flow tank, if the self-produced sulfuric acid delivery system is insufficient, the purchased sulfuric acid delivery system is started, and the switching valve is opened, and the purchased sulfuric acid delivery system is used to supplement the supply of acid.

[0011] In one of the embodiments, when the acid production device needs to be maintained and the high-positioned sulfuric acid tank is in a normal state: The second acid tank inlet valve is closed, the self-produced sulfuric acid delivery system is disconnected from the high-positioned sulfuric acid tank, the first acid tank inlet valve is opened, and the high-positioned sulfuric acid tank is supplied with acid by the purchased sulfuric acid delivery system; When the liquid level in the acid intermediate tank is < 10%, the acid production device is stopped, and the acid product pump, the second pump inlet valve, the second pump outlet valve, and the acid tank acid injection valve are closed, and the acid production device is maintained; After the maintenance of the acid production device is completed, the first acid tank inlet valve is closed, the switching valve and the acid tank acid injection valve are opened, the acid production device is started, the sulfuric acid supplied by the purchased sulfuric acid delivery system enters the acid intermediate tank through the first connecting pipe, the fourth pipeline, and the second backflow pipeline, when the liquid level in the acid intermediate tank is > 70%, the acid tank acid injection valve is closed, and the acid supply mode of the insufficient self-produced acid condition is restored, that is, the switching valve is closed, the first acid tank inlet valve and the second acid tank inlet valve are reopened, the second pump inlet valve and the second pump outlet valve are opened, and the acid product pump is started.

[0012] In one of the embodiments, when the sulfuric acid high tank and the acid making device need to be overhauled, the first acid tank inlet valve, the pump backflow valve, the second acid tank inlet valve, the acid outlet valve, the acid tank acid injection valve, the second pump inlet valve and the first pump inlet valve are closed, the acid product pump is closed, the sulfuric acid conveying pump is opened, the first pump inlet valve, the first pump outlet valve, the switching valve, the self-produced acid inlet full-flow tank valve and the acid inlet full-flow tank valve are opened, and the purchased sulfuric acid conveying system directly supplies acid to the mother liquor full-flow tank; after the sulfuric acid high tank and the acid making device are overhauled, and the liquid level of the acid tank reaches the standard, the purchased sulfuric acid conveying system and the self-produced sulfuric acid conveying system supply acid to the sulfuric acid high tank at the same time according to the acid supply mode of the self-produced acid insufficient working condition.

[0013] In summary, the present application has the following advantages: The present application connects the self-produced sulfuric acid conveying system and the purchased sulfuric acid conveying system with the sulfuric acid high tank and the mother liquor full-flow tank, so that the conveying systems are combined and the replacement and exchange optimization function is added, thereby ensuring continuous production and replacing manual operation during maintenance of system equipment components, preventing sulfur content of coal gas from exceeding the standard and ensuring safety of workers; The present application solves the problem of manual operation directly contacting with sulfuric acid medium for acid injection, realizes online mechanical conveying and injection of acid and ensures safety of workers; The present application realizes the multi-directionality and complementarity of the sulfuric acid conveying system, makes up for the singleness of the original conveying system, ensures continuous operation stability of waste heat of the sulfuric acid conveying system, improves stability of the production system and the use system and realizes one pipe with multiple purposes. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a schematic diagram of the present application.

[0015] In the figure: 1, oil depot sulfuric acid storage tank, 2, acid intermediate tank, 3, acid making device, 4, sulfuric acid high tank, 5, mother liquor full-flow tank; 101, sulfuric acid conveying pump, 102, first pump inlet valve, 103, first pump outlet valve, 104, pump backflow valve, 105, first acid tank inlet valve, 106, switching valve, 201, acid product pump, 202, second pump inlet valve, 203, second pump outlet valve, 204, acid tank acid injection valve, 205, second acid tank inlet valve, 206, self-produced acid inlet full-flow tank valve, 207, acid backflow valve, 208, acid cooler, 401, acid outlet valve, 402, diffuser pipe, 501, acid inlet full-flow tank valve. DETAILED DESCRIPTION

[0016] The present application will be described in detail below in combination with the drawings and examples.

[0017] It should be noted that the orientation words such as "upper" and "lower" involved in the present application are relative to the view angle of the drawings and are only for the convenience of description and cannot be understood as a limitation on the technical solutions.

[0018] As Figure 1 shown in the figure, the application provides a sulfuric acid delivery system with multi-source switching function, comprising a sulfuric acid high tank 4, a mother liquor full-flow tank 5, a self-produced sulfuric acid delivery system and a purchased sulfuric acid delivery system; The sulfuric acid high tank 4 is connected with the mother liquor full-flow tank 5 through a first pipeline, and an acid outlet valve 401 and an acid inlet full-flow tank valve 501 are arranged on the first pipeline, with the acid outlet valve 401 located upstream of the acid inlet full-flow tank valve 501; The purchased sulfuric acid delivery system comprises an oil depot sulfuric acid storage tank 1 and a sulfuric acid delivery pump 101, the oil depot sulfuric acid storage tank 1 is connected with the sulfuric acid high tank 4 through a second pipeline, and the sulfuric acid delivery pump 101 is arranged on the second pipeline, wherein a first pump inlet valve 102 is arranged upstream of the sulfuric acid delivery pump 101, a first pump outlet valve 103 is arranged downstream of the sulfuric acid delivery pump 101, and a first acid tank inlet valve 105 is arranged at the downstream output end of the second pipeline; The self-produced sulfuric acid delivery system comprises an acid production device 3, an acid intermediate tank 2 and an acid product pump 201, the acid production device 3 is connected with the acid intermediate tank 2 through a third pipeline, the acid intermediate tank 2 is connected with the sulfuric acid high tank 4 through a fourth pipeline, and the acid product pump 201 is arranged on the fourth pipeline, wherein a second pump inlet valve 202 is arranged upstream of the acid product pump 201, a second pump outlet valve 203 is arranged downstream of the acid product pump 201, and a second acid tank inlet valve 205 is arranged at the downstream output end of the fourth pipeline; The second pipeline and the fourth pipeline are communicated through a first connecting pipeline, a switching valve 106 is arranged on the first connecting pipeline, the connection point of the first connecting pipeline and the second pipeline is located between the first acid tank inlet valve 105 and the first pump outlet valve 103, and the connection point of the first connecting pipeline and the fourth pipeline is located between the second acid tank inlet valve 205 and the second pump outlet valve 203; The first pipeline and the fourth pipeline are communicated through a second connecting pipeline, a self-produced acid inlet full-flow tank valve 501206 is arranged on the second connecting pipeline, the connection point of the second connecting pipeline and the first pipeline is located between the acid outlet valve 401 and the acid inlet full-flow tank valve 501, and the connection point of the second connecting pipeline and the fourth pipeline is located downstream of the second pump outlet valve 203; Liquid level sensors are arranged in the acid intermediate tank 2, the sulfuric acid high tank 4 and the oil depot sulfuric acid storage tank 1 to monitor the liquid level height in the liquid tank.

[0019] In combination Figure 1It can be known that the purchased sulfuric acid conveying system is communicated with the first pipeline through the first connecting pipeline and the second connecting pipeline, the self-produced sulfuric acid conveying system is communicated with the first pipeline through the second connecting pipeline, and the purchased sulfuric acid conveying system and the self-produced sulfuric acid conveying system realize switching effect through valve opening and closing control, that is, the sulfuric acid of the purchased sulfuric acid conveying system can be conveyed to the sulfuric acid high tank 4 through the pipeline of the self-produced sulfuric acid conveying system, the sulfuric acid of the self-produced sulfuric acid conveying system can also be conveyed to the sulfuric acid high tank 4 through the pipeline of the purchased sulfuric acid conveying system, and the purchased sulfuric acid conveying system and the self-produced sulfuric acid conveying system can both bypass the sulfuric acid high tank 4 and directly convey to the mother liquor full-flow tank 5. The present application has a double-acid source input mode, has the functions of self-produced acid and purchased acid double-source mutual backup, emergency bypass acid supply and intelligent safety control.

[0020] Further, the first backflow pipeline is arranged between the second pipeline and the oil depot sulfuric acid storage tank 1, the pump backflow valve 104 is arranged on the first backflow pipeline, the connection point of the first backflow pipeline and the second pipeline is located between the first acid tank inlet valve 105 and the first pump outlet valve 103, more specifically, the connection point of the first backflow pipeline and the second pipeline is located downstream of the first pump outlet valve 103 and upstream of the connection point of the first connecting pipeline and the second pipeline. In the case of opening the pump backflow valve 104, the sulfuric acid in the second pipeline can flow back to the oil depot sulfuric acid storage tank 1. It is easy to understand that the opening and closing of the pump backflow valve 104 is determined according to actual production.

[0021] Further, the second backflow pipeline is arranged between the fourth pipeline and the acid intermediate tank 2, the acid tank acid injection valve 204 is arranged on the second backflow pipeline, the connection point of the second backflow pipeline and the fourth pipeline is between the second acid tank inlet valve 205 and the second pump outlet valve 203, more specifically, the connection point of the second backflow pipeline and the fourth pipeline is located downstream of the second pump outlet valve 203 and upstream of the connection point of the second connecting pipeline and the fourth pipeline. In the case of opening the acid tank acid injection valve 204, the sulfuric acid in the fourth pipeline can flow back to the acid intermediate tank 2. It is easy to understand that the opening and closing of the acid tank acid injection valve 204 is determined according to actual production.

[0022] Further, the third backflow pipeline is arranged between the third pipeline and the fourth pipeline, the acid backflow valve 207 is arranged on the third backflow pipeline, and the connection point of the third backflow pipeline and the fourth pipeline is located between the acid product pump 201 and the second pump outlet valve 203.

[0023] Further, the acid cooler 208 is further arranged on the third backflow pipeline, and the acid cooler 208 is located upstream of the acid backflow valve 207.

[0024] The acid cooler 208 functions to cool the high-temperature sulfuric acid of 120-140°C produced by the acid production device 3 to 40-50°C, so as to prevent corrosion of the high-temperature sulfuric acid to the equipment.

[0025] Further, the sulfuric acid high tank 4 is provided with a diffusion pipe 402.

[0026] Based on the above-mentioned sulfuric acid delivery system with multi-source switching function, the present application further proposes a corresponding control method as follows: When the sulfuric acid high tank 4 and the acid production device 3 are both in normal state: If the liquid level height in the sulfuric acid high tank 4 is less than 40%, it indicates that the self-produced sulfuric acid delivery system is insufficient, and then the purchased sulfuric acid delivery system is started to deliver sulfuric acid to the sulfuric acid high tank 4; If the liquid level height in the sulfuric acid high tank 4 is greater than 90%, it indicates that there is a possibility of excess self-produced sulfuric acid, and then the purchased sulfuric acid delivery system stops delivering sulfuric acid to the sulfuric acid high tank 4, the switching valve 106 between the self-produced sulfuric acid delivery system and the purchased sulfuric acid delivery system is opened, and the pump backflow valve 104 in the purchased sulfuric acid delivery system is opened, and part of the sulfuric acid from the self-produced sulfuric acid delivery system flows into the oil depot sulfuric acid storage tank 1 for storage; If the liquid level height in the sulfuric acid high tank 4 is greater than or equal to 95%, the self-produced sulfuric acid delivery system stops delivering sulfuric acid to the sulfuric acid high tank 4, the switching valve 106 between the self-produced sulfuric acid delivery system and the purchased sulfuric acid delivery system is opened, and the pump backflow valve 104 in the purchased sulfuric acid delivery system is opened, and all of the sulfuric acid from the self-produced sulfuric acid delivery system flows into the oil depot sulfuric acid storage tank 1 for storage.

[0027] In the present application, the function of the mother liquor full-flow tank 5 is to continuously supplement sulfuric acid to maintain the acidity of the mother liquor, and to produce ammonium sulfate through pickling and to periodically increase the acidity to prevent the internal equipment from being blocked by crystalline substances; during normal operation of the mother liquor full-flow tank 5, the acid outlet valve 401 and the acid inlet full-flow tank valve 501 are in an open state, and a certain amount of acid is added according to the acidity of the mother liquor, such as 0.7-2.0 m 3 / h. The sulfuric acid high tank 4 is higher than the mother liquor full-flow tank 5, and continuously supplies acid to the mother liquor full-flow tank 5 through the height difference to ensure the normal operating acidity of the mother liquor, and the function of the sulfuric acid high tank 4 is to ensure the amount of acid for the production of the saturator.

[0028] In the present application, when the sulfuric acid high tank 4 is in a normal state, the acid outlet valve 401 and the acid inlet full-flow tank valve 501 are maintained in an open state, the self-produced acid inlet full-flow tank valve 501206 is maintained in a closed state, and all of the sulfuric acid supplied by the self-produced sulfuric acid delivery system and / or the purchased sulfuric acid delivery system flows into the sulfuric acid high tank 4, and then flows from the sulfuric acid high tank 4 into the mother liquor full-flow tank 5.

[0029] In the present application, if it is not specified that the self-produced sulfuric acid delivery system stops supplying acid, it means that the self-produced sulfuric acid delivery system maintains acid supply, that is, the acid production device 3 and the acid product pump 201 are always in a working state, and the present application preferentially uses the self-produced sulfuric acid delivery system to supply acid to the sulfuric acid high tank 4.

[0030] In the present application, the control logic of the self-produced sulfuric acid delivery system for acid supply is: the acid production device 3 is started, the second pump inlet valve 202, the second pump outlet valve 203, and the second acid tank inlet valve 205 are opened, the acid product pump 201 is started, the switching valve 106, the self-produced acid full-flow tank valve 501206, and the acid tank liquid injection valve are closed, and the sulfuric acid produced by the acid production device 3 is delivered along the fourth pipeline after passing through the acid intermediate tank 2. Conversely, if there is no special instruction, the stop of the self-produced sulfuric acid delivery system for acid supply means that the second acid tank inlet valve 205 is closed, and the self-produced sulfuric acid delivery system itself maintains normal operation, and the produced sulfuric acid enters the purchased sulfuric acid delivery system through the opening of the switching valve 106.

[0031] In the present application, the control logic of the purchased sulfuric acid delivery system for acid supply is: the first pump inlet valve 102, the first pump outlet valve 103, and the first acid tank inlet valve 105 are opened, the sulfuric acid delivery pump 101 is started, the switching valve 106 and the pump backflow valve 104 are closed, and the sulfuric acid in the oil depot sulfuric acid storage tank 1 is delivered to the sulfuric acid high tank 4 through the second pipeline. Conversely, the stop of the purchased sulfuric acid delivery system for acid supply means that the first acid tank inlet valve 105 is closed, and the first pump inlet valve 102, the first pump outlet valve 103, and the sulfuric acid delivery pump 101 are closed, and the switching valve 106 and the pump backflow valve 104 are opened or closed according to the actual situation. Preferably, the purchased sulfuric acid delivery system for acid supply includes a continuous delivery state and an intermittent delivery state, which is determined according to the actual production situation.

[0032] After the sulfuric acid produced by the acid production device 3 enters the acid intermediate tank 2 through the third pipeline, the self-produced acid is delivered to the sulfuric acid high tank 4 through the acid product pump 201 along the fourth pipeline, which is the continuous production delivery mode of the self-produced sulfuric acid delivery system. When the production of the acid production device 3 is excessive, the amount of sulfuric acid input into the sulfuric acid high tank 4 is more than the consumption of sulfuric acid in the production of ammonium sulfate, and the liquid level in the sulfuric acid high tank 4 continuously rises to the high liquid level, the pump backflow valve 104 and the switching valve 106 of the purchased sulfuric acid delivery system can be opened, the first pump outlet valve 103, the first pump inlet valve 102, and the first acid tank inlet valve 105 are closed, at this time, the self-produced sulfuric acid delivery system is connected with the purchased sulfuric acid delivery system, the excess self-produced acid is delivered to the oil depot sulfuric acid storage tank 1 for storage, which not only ensures the continuous operation of the acid production device 3, but also ensures the safe operation liquid level of the sulfuric acid high tank 4, at this time, part of the self-produced sulfuric acid is still delivered to the sulfuric acid high tank 4, if the liquid level in the sulfuric acid high tank 4 continues to rise, the second acid tank inlet valve 205 is closed, and all the self-produced acid flows into the oil depot sulfuric acid storage tank 1 for storage. It is easy to understand that when the liquid level in the sulfuric acid high tank 4 decreases to the normal height, the self-produced sulfuric acid delivery system is disconnected with the purchased sulfuric acid delivery system, the self-produced sulfuric acid delivery system again delivers sulfuric acid to the sulfuric acid high tank 4, that is, the self-produced sulfuric acid delivery system is preferably used to supply sulfuric acid.

[0033] When the sulfuric acid high tank 4 is in the cleaning and maintenance state, the self-produced acid inlet full-flow tank valve 501206 is opened, the first acid tank inlet valve 105, the second acid tank inlet valve 205 and the acid outlet valve 401 are closed, and acid is directly supplied to the mother liquor full-flow tank 5, and the amount of acid added is controlled according to the mother liquor acidity.

[0034] When the liquid level of the acid intermediate tank 2 in the self-produced sulfuric acid delivery system continuously decreases to approach the lower limit of the process requirement, it indicates that the self-produced acid is insufficient at this time, the first pump inlet valve 102, the first pump outlet valve 103, the first acid tank inlet valve 105 and the sulfuric acid delivery pump 101 are started, and acid is supplied to the sulfuric acid high tank 4 through the self-produced sulfuric acid delivery system and the purchased sulfuric acid delivery system to meet the production requirements.

[0035] When the liquid level of the acid intermediate tank 2 in the self-produced sulfuric acid delivery system continuously rises to approach the upper limit of the process requirement, it indicates that the self-produced acid is excessive at this time, the first pump inlet valve 102, the first pump outlet valve 103 and the first acid tank inlet valve 105 are closed, the supply of acid by the purchased sulfuric acid delivery system is suspended, and at the same time, the switching valve 106 and the pump backflow valve 104 are started, the self-produced sulfuric acid delivery system is connected with the oil depot sulfuric acid storage tank 1, and the excess sulfuric acid is stored in the oil depot sulfuric acid storage tank 1. If the self-produced acid is too excessive to cause the liquid level in the sulfuric acid high tank 4 to be too high, the second acid tank inlet valve 205 is continuously closed, and the self-produced acid is all stored in the oil depot sulfuric acid storage tank 1.

[0036] When the acid production device 3 is in the state of shutdown for maintenance, the self-produced sulfuric acid delivery system is disconnected from the sulfuric acid high tank 4, the first pump inlet valve 102, the first pump outlet valve 103 and the first acid tank inlet valve 105 are opened, and the sulfuric acid delivery pump 101 is started, and the purchased sulfuric acid delivery system intermittently delivers sulfuric acid according to the liquid level of the sulfuric acid high tank 4; when the acid production device 3 completes the production of acid, the acid tank acid injection valve 204 and the switching valve 106 are opened, part of the sulfuric acid of the purchased sulfuric acid delivery system is injected into the acid intermediate tank 2, until the acid liquid in the acid intermediate tank 2 reaches the process requirement, then the switching valve 106 is closed and the supply of acid to the sulfuric acid high tank 4 by the purchased sulfuric acid delivery system is stopped, and the supply of acid to the sulfuric acid high tank 4 by the self-produced sulfuric acid delivery system is restored.

[0037] Specifically, when the sulfuric acid high tank 4 is in the state of maintenance and the acid production device 3 is in the normal state: The first acid tank inlet valve 105, the second acid tank inlet valve 205 and the acid outlet valve 401 are closed, the self-produced acid inlet full-flow tank valve 501206 is opened, the acid inlet full-flow tank valve 501 is maintained in the open state, the self-produced sulfuric acid delivery system is preferentially used to supply acid to the mother liquor full-flow tank 5, if the self-produced sulfuric acid delivery system is insufficient in self-produced acid, the purchased sulfuric acid delivery system is started, and the switching valve 106 is opened, and the purchased sulfuric acid delivery system supplements the supply of acid.

[0038] Specifically, when the acid production device 3 needs to be maintained and the sulfuric acid high tank 4 is in the normal state: Close the second acid tank inlet valve 205, the self-produced sulfuric acid delivery system is disconnected with the sulfuric acid high tank 4, open the first acid tank inlet valve 105, the sulfuric acid high tank 4 is supplied by the purchased sulfuric acid delivery system; When the liquid level of the acid intermediate tank 2 is less than 10%, stop the acid production device 3, and close the acid product pump 201, the second pump inlet valve 202, the second pump outlet valve 203 and the acid tank filling valve 204, and maintain the acid production device 3; After the maintenance of the acid production device 3 is completed, close the first acid tank inlet valve 105, open the switching valve 106 and the acid tank filling valve 204, start the acid production device 3, and the purchased sulfuric acid delivery system supplies the sulfuric acid along the first connecting pipe, the fourth pipe and the second reflux pipe to the acid intermediate tank 2, when the liquid level of the acid intermediate tank 2 is greater than 70%, close the acid tank filling valve 204, and restore the acid supply mode of the insufficient self-produced acid condition, that is, close the switching valve 106, reopen the first acid tank inlet valve 105 and the second acid tank inlet valve 205, open the second pump inlet valve 202 and the second pump outlet valve 203, and start the acid product pump 201. It should be noted that after the maintenance of the acid production device 3 is completed, the supply of sulfuric acid to the sulfuric acid high tank 4 is temporarily disconnected, and the acid is supplied to the acid intermediate tank 2 to meet the liquid level requirement, and then the sulfuric acid is supplied to the sulfuric acid high tank 4 again. Since the sulfuric acid high tank 4 contains sulfuric acid, the temporary stop of the supply of sulfuric acid has no effect on production.

[0039] Specifically, when the sulfuric acid high tank 4 and the acid production device 3 both need to be maintained, the first acid tank inlet valve 105, the pump reflux valve 104, the second acid tank inlet valve 205, the acid outlet valve 401, the acid tank filling valve 204, the second pump inlet valve 202 and the first pump inlet valve 102 are closed, the acid product pump 201 is closed, the sulfuric acid delivery pump 101 is opened, the first pump inlet valve 102, the first pump outlet valve 103, the switching valve 106, the self-produced acid full-flow tank valve 501206 and the acid full-flow tank valve 501 are opened, and the purchased sulfuric acid delivery system directly supplies acid to the mother liquor full-flow tank 5; after the maintenance of the sulfuric acid high tank 4 and the acid production device 3 is completed, and the liquid level of the acid intermediate tank 2 meets the standard, the purchased sulfuric acid delivery system and the self-produced sulfuric acid delivery system supply acid to the sulfuric acid high tank 4 simultaneously according to the acid supply mode of the insufficient self-produced acid condition.

[0040] The above only describes the preferred embodiments of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiments. Any technical solutions falling within the concept of the present application shall fall within the protection scope of the present application. It should be noted that for ordinary technical personnel in the technical field, some improvements and refinements without departing from the principles of the present application shall also be considered as falling within the protection scope of the present application.

Claims

1. A sulfuric acid delivery system with multi-source switching function, characterized in that, It includes a high-level sulfuric acid tank (4), a full-flow mother liquor tank (5), and a self-produced sulfuric acid conveying system and a purchased sulfuric acid conveying system; The sulfuric acid high-level tank (4) is connected to the mother liquor full-flow tank (5) through the first pipe. An acid outlet valve (401) and an acid inlet full-flow tank valve (501) are installed on the first pipe. The acid outlet valve (401) is located upstream of the acid inlet full-flow tank valve (501). The purchased sulfuric acid delivery system includes an oil depot sulfuric acid storage tank (1) and a sulfuric acid delivery pump (101). The oil depot sulfuric acid storage tank (1) is connected to the sulfuric acid high-level tank (4) through a second pipeline. The sulfuric acid delivery pump (101) is installed on the second pipeline. A first pump inlet valve (102) is installed upstream of the sulfuric acid delivery pump (101), a first pump outlet valve (103) is installed downstream of the sulfuric acid delivery pump (101), and a first acid tank inlet valve (105) is installed at the downstream output end of the second pipeline. The self-produced sulfuric acid delivery system includes an acid production device (3), an acid intermediate tank (2), and an acid product pump (201). The acid production device (3) is connected to the acid intermediate tank (2) through a third pipeline. The acid intermediate tank (2) is connected to the sulfuric acid high tank (4) through a fourth pipeline. The acid product pump (201) is installed on the fourth pipeline. A second pump inlet valve (202) is installed upstream of the acid product pump (201), a second pump outlet valve (203) is installed downstream of the acid product pump (201), and a second acid tank inlet valve (205) is installed at the downstream output end of the fourth pipeline. The second pipeline and the fourth pipeline are connected through the first connecting pipeline. A switching valve (106) is installed on the first connecting pipeline. The connection point between the first connecting pipeline and the second pipeline is located between the first acid tank inlet valve (105) and the first pump outlet valve (103). The connection point between the first connecting pipeline and the fourth pipeline is located between the second acid tank inlet valve (205) and the second pump outlet valve (203). The first pipeline and the fourth pipeline are connected by a second connecting pipeline. The second connecting pipeline is equipped with a self-generated acid inlet full flow tank valve (501) (206). The connection point between the second connecting pipeline and the first pipeline is located between the acid outlet valve (401) and the acid inlet full flow tank valve (501). The connection point between the second connecting pipeline and the fourth pipeline is located downstream of the second pump outlet valve (203). Liquid level sensors are installed in the acid intermediate tank (2), the sulfuric acid high tank (4), and the sulfuric acid storage tank (1) of the oil depot to monitor the liquid level height in the tank.

2. The sulfuric acid delivery system with multi-source switching function as described in claim 1, characterized in that, A first return pipe is set between the second pipe and the sulfuric acid storage tank (1) of the oil depot. A pump return valve (104) is set on the first return pipe. The connection point between the first return pipe and the second pipe is located between the inlet valve (105) of the first acid tank and the outlet valve (103) of the first pump.

3. The sulfuric acid delivery system with multi-source switching function as described in claim 2, characterized in that, A second reflux pipe is set between the fourth pipe and the acid intermediate tank (2). An acid tank injection valve (204) is set on the second reflux pipe. The connection point between the second reflux pipe and the fourth pipe is between the second acid tank inlet valve (205) and the second pump outlet valve (203).

4. The sulfuric acid delivery system with multi-source switching function as described in claim 1, characterized in that, A third reflux pipe is set between the third pipe and the fourth pipe, and an acid reflux valve (207) is set on the third reflux pipe. The connection point between the third reflux pipe and the fourth pipe is located between the acid product pump (201) and the outlet valve (203) of the second pump.

5. The sulfuric acid delivery system with multi-source switching function as described in claim 4, characterized in that, An acid cooler (208) is also installed on the third return pipe, and the acid cooler (208) is located upstream of the acid return valve (207).

6. A control method for a sulfuric acid delivery system with multi-source switching function, characterized in that, The following applies to the sulfuric acid delivery system with multi-source switching function as described in claim 3: When both the high-level sulfuric acid tank (4) and the acid production unit (3) are in normal condition: If the liquid level in the high sulfuric acid tank (4) is less than 40%, it indicates that the self-produced sulfuric acid transport system is insufficient. In this case, the purchased sulfuric acid transport system will be activated to transport sulfuric acid to the high sulfuric acid tank (4). If the liquid level in the high sulfuric acid tank (4) is greater than 90%, there is a possibility of excess self-produced acid. Then, the external sulfuric acid delivery system will stop delivering sulfuric acid to the high sulfuric acid tank (4), and the switching valve (106) between the self-produced sulfuric acid delivery system and the external sulfuric acid delivery system will be opened, as well as the pump return valve (104) in the external sulfuric acid delivery system will be opened. The sulfuric acid from the self-produced sulfuric acid delivery system will flow into the sulfuric acid storage tank (1) of the oil depot for storage. If the liquid level in the high sulfuric acid tank (4) is ≥95%, the self-produced sulfuric acid delivery system will stop delivering sulfuric acid to the high sulfuric acid tank (4), and the switching valve (106) between the self-produced sulfuric acid delivery system and the purchased sulfuric acid delivery system will be opened, as will the pump return valve (104) in the purchased sulfuric acid delivery system. All the sulfuric acid from the self-produced sulfuric acid delivery system will flow into the sulfuric acid storage tank (1) of the oil depot for storage.

7. The control method as described in claim 6, characterized in that, When the sulfuric acid high-level tank (4) is under maintenance while the acid production unit (3) is in normal operation: Close the first acid tank inlet valve (105), the second acid tank inlet valve (205) and the acid outlet valve (401), and open the self-produced acid inlet full flow tank valve (501) (206). The acid inlet full flow tank valve (501) is kept open. Acid is supplied to the mother liquor full flow tank (5) first through the self-produced sulfuric acid delivery system. If the self-produced sulfuric acid delivery system is insufficient, the purchased sulfuric acid delivery system is restarted and the switching valve (106) is opened to supplement the acid supply.

8. The control method as described in claim 6, characterized in that, When the acid production unit (3) needs maintenance while the sulfuric acid high-level tank (4) is in normal condition: Close the inlet valve (205) of the second acid tank, disconnect the connection between the self-produced sulfuric acid delivery system and the high-level sulfuric acid tank (4), open the inlet valve (105) of the first acid tank, and supply sulfuric acid to the high-level sulfuric acid tank (4) from the purchased sulfuric acid delivery system; When the liquid level in the intermediate acid tank (2) is <10%, stop the acid production device (3), and close the acid product pump (201), the second pump inlet valve (202), the second pump outlet valve (203) and the acid tank injection valve (204) to repair the acid production device (3). After the maintenance of the acid production unit (3) is completed, the first acid tank inlet valve (105) is closed, the switching valve (106) and the acid tank injection valve (204) are opened, the acid production unit (3) is started, and the acid supplied by the purchased sulfuric acid delivery system enters the acid intermediate tank (2) along the first connecting pipe, the fourth pipe and the second return pipe. When the liquid level of the acid intermediate tank (2) is >70%, the acid tank injection valve (204) is closed, and the acid supply mode is restored to the condition of insufficient self-produced acid. That is, the switching valve (106) is closed, the first acid tank inlet valve (105) and the second acid tank inlet valve (205) are reopened, the second pump inlet valve (202) and the second pump outlet valve (203) are opened, and the acid product pump (201) is started.

9. The control method as described in claim 6, characterized in that, When both the high-pressure sulfuric acid tank (4) and the acid production unit (3) require maintenance, close the first acid tank inlet valve (105), pump reflux valve (104), second acid tank inlet valve (205), acid outlet valve (401), acid tank injection valve (204), second pump inlet valve (202), and first pump inlet valve (102), shut down the acid product pump (201), start the sulfuric acid transfer pump (101), and open the first pump inlet valve (102) and first pump outlet valve. (103), switching valve (106), self-produced acid in full flow tank valve (501) (206) and acid in full flow tank valve (501), the purchased sulfuric acid delivery system directly supplies acid to the mother liquor full flow tank (5); after the maintenance of the sulfuric acid high tank (4) and the acid production device (3) is completed, after the liquid level of the acid intermediate tank (2) reaches the standard, according to the acid supply mode of insufficient self-produced acid, the purchased sulfuric acid delivery system and the self-produced sulfuric acid delivery system simultaneously supply acid to the sulfuric acid high tank (4).

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