System and method for treating desorbed gas from a blast furnace gas desulfurization

Abstract

The present application is a kind of system and method for treating desorption gas of blast furnace gas desulfurization, the system for treating desorption gas of blast furnace gas desulfurization includes a plurality of adsorption desulfurization towers, the inside of each adsorption desulfurization tower is filled with adsorption material with adsorption capacity and desorption regeneration after heating respectively, the gas inlet of each adsorption desulfurization tower is connected with blast furnace gas inlet pipe and desorption gas outlet pipe respectively, and the blast furnace gas inlet pipe and desorption gas outlet pipe are connected with blast furnace respectively; the gas outlet of each adsorption desulfurization tower is connected with clean gas outlet pipe and regeneration desorption gas inlet pipe respectively, the clean gas outlet pipe is connected with clean blast furnace gas pipe network, and the regeneration desorption gas inlet pipe is connected with clean gas outlet pipe. The present application solves the technical problems of low processing efficiency and economy, and poor processing effect for the desorption gas generated by blast furnace gas desulfurization.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of blast furnace gas treatment, and in particular to a system and method for treating desorbed blast furnace gas after desulfurization. BACKGROUND

[0002] Blast furnace gas is a main by-product produced in the iron-making process, which is a colorless and odorless combustible gas. The theoretical combustion temperature of blast furnace gas is 1400℃-1500℃, and the ignition point is about 700℃. The characteristics of blast furnace gas are low calorific value (3300kJ / Nm 3 ~4200kJ / Nm 3 ) and large gas production, and the explosion range of blast furnace gas mixed with air is 40%~70%. The main components of blast furnace gas are CO (25%~30%), H2 (1.5%~3.0%), CH4 (10.2%~0.5%), N2 (55%~60%), CO2 (9%~12%) and O2 (0.2%~0.4%). The content of sulfur in blast furnace gas is 40mg / m 3 ~200mg / m 3 , in which inorganic sulfur mainly H2S is 10mg / m 3 ~50mg / m 3 , and organic sulfur mainly COS and CS2 is 80mg / m 3 ~150mg / m 3 . In the process of desulfurization of blast furnace gas, inorganic sulfur (mainly H2S) is easy to remove, but organic sulfur is difficult to remove.

[0003] In recent years, with the widespread application of dry bag dust removal and residual pressure turbine power generation device (TRT) of blast furnace gas, the pressure energy and thermal energy of blast furnace gas have been fully recovered. The blast furnace gas after recovery of pressure energy and thermal energy by TRT device is sent to hot blast stove, heating furnace, coke oven, boiler, sintering, pelletizing and other users for use as fuel. After combustion of blast furnace gas, the main form of sulfur in flue gas is SO2, and the content is 45mg / m 3 ~185mg / m 3 . The flue gas needs to be purified to meet the emission standards. With the strict requirements of environmental protection, the emission limit of particulate matter after combustion of blast furnace gas is 10mg / m 3 , the emission limit of SO2 in flue gas is 35mg / m 3 , and the emission limit of nitrogen oxides is 50mg / m 3 . In some areas, the concentration of H2S in blast furnace gas and coke oven gas is required to be less than 20mg / m 3The traditional desulfurization method is to desulfurize the flue gas, mainly using calcium method, magnesium method, sodium method, ammonia method, organic alkali method and other processes. However, compared with blast furnace gas, the volume of flue gas after combustion increases, the temperature is high, and the pressure is low, which will lead to large desulfurization equipment, large water consumption, separate treatment of circulating water, high desulfurization cost, secondary pollution and other shortcomings. The method for source treatment of blast furnace gas mainly uses traditional wet scrubbing desulfurization after TRT device, among which H2S, SO2 and other substances are easy to remove, but COS, CS2 and other substances in blast furnace gas are not easy to remove, which leads to the SO2 content in flue gas after combustion still exceeding the standard. At present, there is no more economical and easy method for removing H2S, COS and other sulfides in blast furnace gas. Under the premise of ensuring full recovery of blast furnace gas pressure and heat energy, the blast furnace gas dry desulfurization process can make the SO2 content in flue gas after combustion meet the emission standard. In the dry desulfurization system, the desorption gas after blowing and adsorbing the material contains high concentration of sulfides, so it is necessary to develop a treatment system and method for blast furnace gas desulfurization desorption gas.

[0004] At present, the blast furnace gas dry desulfurization process needs to use clean gas as the regeneration desorption gas. When the adsorption tower reaches a certain saturation degree, the desorption gas is heated to above 220℃ by a heat exchanger to blow and regenerate the adsorption saturated adsorption tower, and the regeneration process is divided into three processes of heating, holding and cold blowing. The desorption gas carries away H2S and organic sulfur and other impurities in the adsorption tower. According to the actual situation of the enterprise, the desorption gas rich in H2S, organic sulfur and tar and other impurities is treated by the corresponding subsequent treatment scheme to ensure that the desorption gas is effectively treated and there is no energy waste. The existing desorption gas treatment has the following schemes:

[0005] I. When the existing plant area has a sintering plant, the low-calorific-value gas is used for sintering machine ignition, and the sintering flue gas desulfurization facility is provided. In this case, the purified blast furnace gas can be used as desorption gas, which carries away H2S and organic sulfur and other impurities in the adsorption tower, and is sent to the sintering plant as fuel gas through the pipe network, and is desulfurized by the desulfurization facility of the sintering machine after combustion. Generally, the sintering flue gas desulfurization facility has 10% excess capacity under normal circumstances, and the sulfur elements in the desorption gas are all transferred to the sintering flue gas, which can increase the SO2 content by 30mg / m 3 ~ 70mg / m 3 , which is much smaller than the excess capacity of the sintering flue gas desulfurization facility. The sintering flue gas mixed with part of the sulfur elements can still achieve standard emission.

[0006] II. When the existing plant has a sintering plant, high-calorific-value gas (such as coke oven gas) is used for sintering machine ignition, and the sintering flue gas desulfurization facility is provided, in which case, the purified coke oven gas can be used as the desorption gas, but due to the low consumption of coke oven gas for single sintering machine ignition, the consumption is generally less than the desorption gas amount, so the process configuration of 2 or more sintering machines is required, and the desorption gas can be sent to the sintering plant through the pipe network as fuel gas.

[0007] III. When the existing plant has a gas power generation facility, and the power plant is equipped with a flue gas desulfurization facility, the desorption gas can be considered to be sent to the power plant through the pipe network as fuel gas, but the flue gas desulfurization facility of the power plant itself has limited processing capacity, and the facility has limited processing surplus capacity, so it is generally difficult to digest all the SO2 content in the desorption gas.

[0008] The main principle of the dry desulfurization of blast furnace gas is to use the adsorption material to adsorb the inorganic sulfur and organic sulfur in the gas to achieve the effect of purifying the gas, and when the adsorption material is saturated, in order to ensure the adsorption effect of the adsorption material, the sulfides attached to the adsorption material must be desorbed, and the current technical solution uses gas as the desorption gas to blow out the sulfides. However, the above-mentioned several desorption gas treatment methods all need to rely on the external sintering, power generation and other supporting flue gas desulfurization facilities, and are limited by the gas types and flue gas treatment capacity of the existing facilities. If there is no supporting facility, the desorption gas will be subjected to wet desulfurization again, which will cause a series of problems such as secondary pollution of desulfurization waste liquid.

[0009] At present, no effective solution has been given to the problems of low treatment efficiency and economy, and poor treatment effect of the desorption gas generated by the desulfurization of blast furnace gas in the related art.

[0010] Therefore, the present inventors propose a system and method for treating desorption gas of blast furnace gas desulfurization based on years of experience and practice in the relevant industry to overcome the defects of the prior art. SUMMARY

[0011] The purpose of the present application is to provide a system and method for treating desorption gas of blast furnace gas desulfurization, which returns the desorption gas containing high-concentration sulfides to the blast furnace for combustion, and most of the sulfides contained in the desorption gas enter the slag after combustion, and the remaining small part of the sulfides is transferred to the blast furnace gas, which can reach a dynamic balance with the sulfides contained in the blast furnace gas to be purified, without the need to add other desorption gas treatment equipment, and has the advantages of simplifying the process, recycling, reducing the cost, avoiding secondary pollution and the like, and is suitable for popularization and use.

[0012] The purpose of the present application can be achieved by the following technical solutions:

[0013] The application provides a system for treating desorbed gas of blast furnace gas desulfurization, comprising a plurality of adsorption desulfurization towers, the inner part of each of the adsorption desulfurization towers is filled with adsorption material with adsorption capacity and capable of desorption and regeneration after heating, the gas inlet of each of the adsorption desulfurization towers is connected with a blast furnace gas inlet pipe and a desorbed gas outlet pipe respectively, and the blast furnace gas inlet pipe and the desorbed gas outlet pipe are connected with a blast furnace respectively; the gas outlet of each of the adsorption desulfurization towers is connected with a clean gas outlet pipe and a regenerated desorbed gas inlet pipe respectively, the clean gas outlet pipe is connected with a clean blast furnace gas pipe network, and the regenerated desorbed gas inlet pipe is connected with the clean gas outlet pipe.

[0014] In a preferred embodiment of the application, the desorbed gas outlet pipe is connected with a desorbed gas tail pipe, the desorbed gas tail pipe is connected with a hot air tail pipe through a plurality of desorbed gas branch pipes, and the hot air tail pipe is connected with the blast furnace through a plurality of hot air branch pipes.

[0015] In a preferred embodiment of the application, the desorbed gas outlet pipe comprises a desorbed gas outlet main pipe and a plurality of desorbed gas outlet branch pipes, one end of each of the desorbed gas outlet branch pipes is connected with the gas inlet of the corresponding adsorption desulfurization tower, the other end of each of the desorbed gas outlet branch pipes is connected with one end of the desorbed gas outlet main pipe, and the other end of the desorbed gas outlet main pipe is connected with the desorbed gas tail pipe.

[0016] In a preferred embodiment of the application, a gas compressor is arranged on the desorbed gas outlet main pipe.

[0017] In a preferred embodiment of the application, a blind plate valve and a butterfly valve are arranged on the desorbed gas outlet main pipe.

[0018] In a preferred embodiment of the application, a quick cut valve is arranged on the desorbed gas outlet main pipe, and the quick cut valve is connected with a combustible gas detection instrument.

[0019] In a preferred embodiment of the application, the blast furnace gas inlet pipe comprises a blast furnace gas inlet main pipe and a plurality of blast furnace gas inlet branch pipes, one end of each of the blast furnace gas inlet branch pipes is connected with the gas inlet of the corresponding adsorption desulfurization tower, the other end of each of the blast furnace gas inlet branch pipes is connected with one end of the blast furnace gas inlet main pipe, and the other end of the blast furnace gas inlet main pipe is connected with blast furnace gas to be purified.

[0020] In a preferred embodiment of the application, the clean gas outlet pipe comprises a clean gas outlet main pipe and a plurality of clean gas outlet branch pipes, one end of each of the clean gas outlet branch pipes is connected with the gas outlet of the corresponding adsorption desulfurization tower, the other end of each of the clean gas outlet branch pipes is connected with one end of the clean gas outlet main pipe, and the other end of the clean gas outlet main pipe is connected with the clean blast furnace gas pipe network.

[0021] In a preferred embodiment of the present application, the regenerated desorbed gas inlet pipe comprises a regenerated desorbed gas inlet main pipe and a plurality of regenerated desorbed gas inlet branch pipes, one end of each of the regenerated desorbed gas inlet branch pipes is connected to the gas outlet of the corresponding adsorption desulfurization tower, one end of each of the regenerated desorbed gas inlet branch pipes is connected to one end of the regenerated desorbed gas inlet main pipe, and the other end of the regenerated desorbed gas inlet main pipe is connected to the clean gas outlet main pipe.

[0022] In a preferred embodiment of the present application, a heater is arranged on the regenerated desorbed gas inlet main pipe.

[0023] The present application provides a method for treating desorbed gas of blast furnace gas desulfurization, comprising the following steps:

[0024] Step S1: The blast furnace gas to be purified is respectively introduced into a plurality of adsorption desulfurization towers to adsorb and remove sulfides and impurities in the blast furnace gas;

[0025] Step S2: After the adsorption material in the adsorption desulfurization tower reaches a preset saturation degree, the clean blast furnace gas generated by each of the adsorption desulfurization towers is heated and returned to the adsorption desulfurization tower;

[0026] Step S3: The sulfides and impurities adsorbed by the adsorption material in each of the adsorption desulfurization towers are desorbed into desorbed gas;

[0027] Step S4: The desorbed gas desorbed from each of the adsorption desulfurization towers is transported to a blast furnace for combustion.

[0028] In a preferred embodiment of the present application, in the step S1, the clean blast furnace gas is transported to a clean blast furnace gas pipe network.

[0029] In a preferred embodiment of the present application, any of the adsorption desulfurization towers is used as a standby adsorption desulfurization tower, and when the adsorption desulfurization tower is in a regenerated state, the standby adsorption desulfurization tower performs adsorption desulfurization operation.

[0030] The system and method for treating desorption gas of blast furnace gas desulfurization has the characteristics and advantages that: the adsorption material is filled in each adsorption desulfurization tower, the inorganic sulfur, organic sulfur and other impurities in the blast furnace gas to be purified are adsorbed and removed by the adsorption material after the blast furnace gas to be purified is introduced into each adsorption desulfurization tower, the desorption gas containing high-concentration sulfides is discharged to the blast furnace through the desorption gas outlet pipe for combustion during the desorption of each adsorption desulfurization tower, most of the sulfides in the desorption gas enter the slag, and the remaining small part of the sulfides is transferred to the blast furnace gas, so that the remaining sulfides after combustion and the sulfides contained in the blast furnace gas to be purified reach dynamic balance, the treatment and standard discharge of the desorption gas are completed without adding other desorption gas treatment equipment, and therefore, the system has the advantages of simplified process, recycling, reduced cost, avoided secondary pollution and the like, and is suitable for popularization and use. BRIEF DESCRIPTION OF DRAWINGS

[0031] The following drawings are only intended to illustrate and explain the present application and do not limit the scope of the present application.

[0032] Among them:

[0033] Figure 1 : is a structural schematic view of the system for treating desorption gas of blast furnace gas desulfurization.

[0034] The reference numerals in the present application are:

[0035] 1, adsorption desulfurization tower; 2, blast furnace gas inlet main pipe;

[0036] 3, blast furnace gas inlet branch pipe; 4, clean gas outlet main pipe;

[0037] 5, clean gas outlet branch pipe; 6, regeneration desorption gas inlet pipe;

[0038] 7, desorption gas outlet pipe; 8, desorption gas tail pipe;

[0039] 9, desorption gas branch pipe; 10, hot air tail pipe;

[0040] 11, hot air branch pipe; 12, gas compressor;

[0041] 13, blind plate valve; 14, butterfly valve;

[0042] 15, quick cut valve; 16, heater;

[0043] 17, clean blast furnace gas pipe network; 18, desorption gas outlet branch pipe;

[0044] 19, regeneration desorption gas inlet branch pipe. DETAILED DESCRIPTION

[0045] In order to have a clearer understanding of the technical features, objectives and effects of the present application, the specific embodiments of the present application will be described with reference to the accompanying drawings.

[0046] Embodiment one

[0047] As shown in Figure 1 The present application provides a system for treating desorbed gas of blast furnace gas desulfurization, which comprises a plurality of adsorption desulfurization towers 1, each of which is internally filled with adsorption material having adsorption capacity and capable of being desorbed and regenerated after being heated, the gas inlet of each of the adsorption desulfurization towers 1 is connected with a blast furnace gas inlet pipe and a desorbed gas outlet pipe respectively, and the blast furnace gas inlet pipe and the desorbed gas outlet pipe are connected with a blast furnace respectively; the gas outlet of each of the adsorption desulfurization towers 1 is connected with a clean gas outlet pipe and a regenerated desorbed gas inlet pipe respectively, the clean gas outlet pipe is connected with a clean blast furnace gas pipe network 17, and the regenerated desorbed gas inlet pipe is connected with the clean gas outlet pipe.

[0048] In the present application, each of the adsorption desulfurization towers 1 is internally filled with adsorption material, after the blast furnace gas to be purified is introduced into each of the adsorption desulfurization towers 1, the adsorption material can adsorb and remove inorganic sulfur, organic sulfur and other impurities in the blast furnace gas, and in the process of desorption and regeneration of each of the adsorption desulfurization towers 1, the desorbed gas containing high-concentration sulfides can be discharged to the blast furnace through the desorbed gas outlet pipe for combustion, so that most of the sulfides (about 85% of the total content of sulfides) in the desorbed gas enter the slag, and the remaining small part of the sulfides (about 15% of the total content of sulfides) are transferred to the blast furnace gas, so that the remaining sulfides after combustion and the sulfides contained in the blast furnace gas to be purified reach a dynamic balance, thereby completing the treatment and standard emission of the desorbed gas without the need to add other desorbed gas treatment equipment, and the present application has the advantages of simplifying the process, recycling, reducing costs, avoiding secondary pollution and the like.

[0049] In an optional embodiment of the present application, as shown in Figure 1 The desorbed gas outlet pipe is connected with a desorbed gas tail pipe 8, the desorbed gas tail pipe 8 is connected with a hot air tail pipe 10 through a plurality of desorbed gas branch pipes 9, and the hot air tail pipe 10 is connected with the blast furnace through a plurality of hot air branch pipes 11. After desorption of each of the adsorption desulfurization towers 1, the desorbed gas rich in high-concentration sulfides flows into the blast furnace through the desorbed gas outlet pipe, the desorbed gas tail pipe 8, the plurality of desorbed gas branch pipes 9, the hot air tail pipe 10 and the plurality of hot air branch pipes 11 in turn, thereby ensuring that the desorbed gas introduced into the blast furnace can be uniformly dispersed in the blast furnace.

[0050] Further, the number of desorption gas branch pipes 9 is greater than or equal to 4, and each desorption gas branch pipe 9 is uniformly and spaced arranged along the circumference of the hot air tail pipe 10. Of course, the number of desorption gas branch pipes 9 can be adjusted according to the length of the hot air tail pipe 10, so that the desorption gas can be uniformly mixed into the hot air tail pipe 10, and the pipe diameter of the desorption gas branch pipe 9 can be, but is not limited to, DN50.

[0051] In an optional embodiment of the present application, as shown in Figure 1 the desorption gas outlet pipe includes a desorption gas outlet main pipe 7 and a plurality of desorption gas outlet branch pipes 18, one end of each desorption gas outlet branch pipe 18 is connected with the gas inlet of the corresponding adsorption desulfurization tower 1, the other end of each desorption gas outlet branch pipe 18 is connected with one end of the desorption gas outlet main pipe 7, and the other end of the desorption gas outlet main pipe 7 is connected with the desorption gas tail pipe 8. A valve group for controlling the on-off of the corresponding desorption gas outlet branch pipe 18 is arranged on each desorption gas outlet branch pipe 18, and the desorption gas in each adsorption desulfurization tower 1 is first introduced into each desorption gas outlet branch pipe 18, and then flows into the desorption gas outlet main pipe 7 through each desorption gas outlet branch pipe 18.

[0052] Further, as shown in Figure 1 the desorption gas outlet main pipe 7 is provided with a gas compressor 12, the desorption gas is pressurized by the gas compressor 12, and then sent into the blast furnace.

[0053] Further, as shown in Figure 1 the desorption gas outlet main pipe 7 is provided with a blind plate valve 13 and a butterfly valve 14, the blind plate valve 13 and the butterfly valve 14 are connected in series on the desorption gas outlet main pipe 7, and the blind plate valve 13 and the butterfly valve 14 are located downstream of the gas compressor 12. The on-off of the desorption gas outlet main pipe 7 can be controlled through the blind plate valve 13 and the butterfly valve 14, and the double setting has higher reliability, which can ensure that the desorption gas will not leak out when the blind plate valve 13 and the butterfly valve 14 are closed.

[0054] Further, as shown in Figure 1 the desorption gas outlet main pipe 7 is provided with a quick cut valve 15, and the quick cut valve 15 is connected with a combustible gas detection instrument. When the combustible gas detection instrument detects a combustible gas leakage, the quick cut valve 15 can be controlled to automatically close, so as to cut off the leakage source of the combustible gas, and the accident can be timely stopped.

[0055] In an optional embodiment of the present application, as shown in Figure 1As shown, the blast furnace gas inlet pipe comprises a blast furnace gas inlet main pipe 2 and a plurality of blast furnace gas inlet branch pipes 3, one end of each blast furnace gas inlet branch pipe 3 is connected with the gas inlet of the corresponding adsorption desulfurization tower 1, the other end of each blast furnace gas inlet branch pipe 3 is connected with one end of the blast furnace gas inlet main pipe 2, the other end of the blast furnace gas inlet main pipe 2 is connected with the blast furnace gas to be purified, and a valve group for controlling the on-off of each blast furnace gas inlet branch pipe 3 is arranged on each blast furnace gas inlet branch pipe 3. The blast furnace gas to be purified is discharged from the blast furnace and is sent into each adsorption desulfurization tower 1 through the blast furnace gas inlet main pipe 2 and each blast furnace gas inlet branch pipe 3 in sequence for desulfurization treatment.

[0056] In an optional embodiment of the present application, as shown in Figure 1 As shown, the clean gas outlet pipe comprises a clean gas outlet main pipe 4 and a plurality of clean gas outlet branch pipes 5, one end of each clean gas outlet branch pipe 5 is connected with the gas outlet of the corresponding adsorption desulfurization tower 1, the other end of each clean gas outlet branch pipe 5 is connected with one end of the clean gas outlet main pipe 4, the other end of the clean gas outlet main pipe 4 is connected with the clean blast furnace gas pipe network 17, and a valve group for controlling the on-off of each clean gas outlet branch pipe 5 is arranged on each clean gas outlet branch pipe 5. The clean gas treated by each adsorption desulfurization tower 1 is returned to the clean gas outlet main pipe 4 through each clean gas outlet branch pipe 5 in sequence and is delivered to the clean blast furnace gas pipe network 17 for supplying users.

[0057] In an optional embodiment of the present application, as shown in Figure 1 As shown, the regeneration desorption gas inlet pipe comprises a regeneration desorption gas inlet main pipe 6 and a plurality of regeneration desorption gas inlet branch pipes 19, one end of each regeneration desorption gas inlet branch pipe 19 is connected with the gas outlet of the corresponding adsorption desulfurization tower 1, one end of each regeneration desorption gas inlet branch pipe 19 is connected with one end of the regeneration desorption gas inlet main pipe 6, the other end of the regeneration desorption gas inlet main pipe 6 is connected with the clean gas outlet main pipe 4, and a valve group for controlling the on-off of each regeneration desorption gas inlet branch pipe 19 is arranged on each regeneration desorption gas inlet branch pipe 19. A small amount of clean blast furnace gas in the clean gas outlet main pipe 4 can be extracted as the regeneration desorption gas, which is heated and returned to each adsorption desulfurization tower 1 for heating the adsorption material, so that the temperature in each adsorption desulfurization tower 1 reaches the desorption regeneration temperature (160-350℃) of the adsorption material, thereby ensuring the desorption regeneration of each adsorption desulfurization tower 1. When each adsorption desulfurization tower 1 is in a maintenance state, the regeneration desorption gas inlet main pipe 6 can also be directly connected with the gas compressor 12, and the blast furnace gas to be purified in each adsorption desulfurization tower 1 is directly returned to the blast furnace for combustion after being compressed by the gas compressor 12, thereby ensuring that the desorption gas entering the blast furnace is continuous and stable, and ensuring the stable operation of the whole system.

[0058] Further, as shown in Figure 1 A heater 16 is arranged on the regeneration desorption gas inlet main pipe 6 for preheating the clean blast furnace gas returned to each adsorption desulfurization tower 1.

[0059] Further, the adsorption material can use, but is not limited to, copper modified ZSM-5 molecular sieve material or zinc modified ZSM-5 molecular sieve material. The adsorption material has the ability to adsorb organic sulfur and inorganic sulfur in the temperature range of 20℃ to 80℃, and has the ability to desorb and regenerate in the temperature range of 160℃ to 350℃.

[0060] The system for treating desorbed gas of blast furnace gas desulfurization of the application has the following characteristics and advantages:

[0061] I. In the system for treating desorbed gas of blast furnace gas desulfurization, the desorbed gas containing high concentration of sulfides can be discharged to the blast furnace through the desorbed gas outlet pipe for combustion during the desorption and regeneration of each adsorption desulfurization tower 1, so that most of the sulfides in the desorbed gas enter the slag, and the remaining small part of the sulfides is transferred to the blast furnace gas, so that the remaining sulfides after combustion and the sulfides contained in the blast furnace gas to be purified reach dynamic equilibrium, thereby completing the treatment and standard emission of the desorbed gas without adding other desorbed gas treatment equipment.

[0062] II. In the system for treating desorbed gas of blast furnace gas desulfurization, the desorbed gas after desorption and regeneration of each adsorption desulfurization tower 1 can be treated by circulation, the subsequent treatment equipment is small in scale and simple in technology, effectively reducing the cost and energy consumption, the blast furnace gas can reach the emission standard, saving energy and without secondary pollution, and being suitable for popularization and use.

[0063] Embodiment II

[0064] As shown in Figure 1 The application provides a method for treating desorbed gas of blast furnace gas desulfurization, which comprises the following steps:

[0065] Step S1: The blast furnace gas to be purified is respectively introduced into a plurality of adsorption desulfurization towers 1 to adsorb and remove sulfides and impurities in the blast furnace gas;

[0066] Step S2: After the adsorption material in the adsorption desulfurization tower 1 reaches a preset saturation degree, the clean blast furnace gas generated by each adsorption desulfurization tower 1 is heated and returned to the adsorption desulfurization tower 1;

[0067] Step S3: The sulfides and impurities adsorbed by the adsorption material in each adsorption desulfurization tower 1 are desorbed into desorbed gas under the condition of temperature rise;

[0068] Step S4: The desorbed gas desorbed from each adsorption desulfurization tower 1 is transported to the blast furnace for combustion.

[0069] Further, the blast furnace gas (in which the content of sulfur is 40 mg / m 3 ~ 200 mg / m 3 , the content of H2S is 10 mg / m 3 ~ 50 mg / m 3 , the content of organic sulfur is 80 mg / m 3 ~ 150 mg / m 3 ) to be purified after the TRT is respectively introduced into a plurality of adsorption desulfurization towers 1, the adsorption material in the adsorption desulfurization tower 1 adsorbs and removes H2S and other inorganic sulfur, COS, CS2 and other organic sulfur and other impurities in the blast furnace gas to be purified, the total sulfur content in the purified blast furnace gas is less than 20 mg / m 3 , and the purified blast furnace gas is delivered to a blast furnace gas pipe network 17.

[0070] In an optional embodiment of the present application, any one of the adsorption desulfurization towers 1 is used as a standby adsorption desulfurization tower, and the standby adsorption desulfurization tower performs the adsorption desulfurization operation in the regeneration state of the adsorption desulfurization tower 1. A small amount of the purified blast furnace gas can be extracted from the main gas outlet pipe 4, pressurized by a pressurizing machine, heated to 160°C ~ 350°C by a heater (an electric heater or a heat exchanger), and then delivered to the adsorption desulfurization tower 1 for regeneration. The regeneration process includes three processes of temperature rising, temperature keeping and cold blowing. In the regeneration process, the adsorbed H2S, impurities and the like in the adsorption material are desorbed into the desorption gas, and are discharged from the adsorption desulfurization tower 1 together with the regeneration desorption gas, which is called desorption desorption gas, and the desorption desorption gas is rich in high-concentration sulfides and other impurities. The desorption desorption gas is pressurized to 0.4 MPa ~ 0.6 MPa by the gas compressor 12 and then delivered to the hot air tail pipe 10. In order to ensure the safety and reliability of the system, the desorption desorption gas needs to be provided with a reliable blind plate valve 13, a butterfly valve 14 and a quick cut valve 15 capable of quick cutting on the desorption gas outlet main pipe 7 before entering the hot air tail pipe 10, and the desorption gas outlet main pipe 7 is connected to the hot air tail pipe 10 through four (or more) desorption gas branch pipes 9. The desorption gas entering the hot air tail pipe 10 is mixed with the blast furnace inlet air and then enters the blast furnace through the air supply branch pipe to be burned, 85% of the sulfides are transferred to the slag, and the remaining small amount of sulfides are transferred to the blast furnace gas, which then enters the adsorption desulfurization tower 1 for desulfurization and purification, and the purified blast furnace gas is delivered to the blast furnace gas pipe network 17.

[0071] In a specific embodiment of the present application, 100,000 Nm 3 / h of blast furnace gas to be purified after the TRT is generated, the total sulfur content in the blast furnace gas to be purified is less than 200 mg / m 3 , the content of H2S is 30%, and the content of COS and CS2 is 70%; the pressure of the blast furnace gas to be purified is 12 kPa ~ 16 kPa, and the dust content is less than 10 mg / m 3The blast furnace gas to be purified is sequentially conveyed into two adsorption desulfurization towers 1 (the other adsorption desulfurization tower 1 is used as a standby adsorption desulfurization tower) through a blast furnace gas inlet main pipe 2 and a plurality of blast furnace gas inlet branch pipes 3, respectively. When the blast furnace gas to be purified passes through the adsorption material in the adsorption desulfurization tower 1, the H2S and other inorganic sulfur and organic sulfur (COS, CS2, etc.) contained in the blast furnace gas to be purified are adsorbed by the adsorption material. The total sulfur content in the purified blast furnace gas (i.e., the purified blast furnace gas) is less than 20 mg / m 3 The purified blast furnace gas is sequentially conveyed to the subsequent section (i.e., the purified blast furnace gas pipe network 17) through the purified gas outlet branch pipes 5 and the purified gas outlet main pipe 4. After the adsorption desulfurization towers 1 are normally operated for 3 days, the two adsorption desulfurization towers 1 are regenerated by desorption. A small amount (3000 Nm 3 / h~5000 Nm 3 / h) of the purified blast furnace gas is extracted from the purified gas outlet main pipe 4. The extracted purified blast furnace gas is heated by a regenerative blower, an electric heater, etc., and is sequentially conveyed into the adsorption desulfurization towers 1 through a regenerative desorption gas inlet main pipe 6, a plurality of regenerative desorption gas inlet branch pipes 19 and the gas outlets of the adsorption desulfurization towers 1. When the regenerative desorption gas (i.e., the purified blast furnace gas) passes through the adsorption material in the adsorption desulfurization tower 1, the adsorption material is heated. A temperature measuring device can be arranged in the adsorption desulfurization tower 1 to monitor the temperature change in the adsorption desulfurization tower 1 in real time. When the temperature of the adsorption material reaches 200℃, the adsorption desulfurization tower 1 is kept warm (the temperature is maintained at 180~210℃). In this process, the adsorption material desorbs the adsorbed H2S and other inorganic sulfur and organic sulfur. After desorption, the H2S and other inorganic sulfur and organic sulfur enter the regenerative gas (i.e., the desorption gas). The total sulfur content in the desorption gas is 10 g / m 3 ~20 g / m 3 The desorption gas in the adsorption desulfurization tower 1 is collected into the desorption gas outlet main pipe 7 through the desorption gas outlet branch pipes 18. The desorption gas is pressurized to 0.4 MPa~0.6 MPa by a gas compressor 12 (the purpose is to collect the desorption gas into the blast furnace hot air) and is sequentially conveyed into a desorption gas tail pipe 8 through a blind valve 13, a butterfly valve 14 and a quick cut valve 15. The desorption gas tail pipe 8 is connected with a plurality of desorption gas branch pipes 9. The desorption gas rich in high-concentration sulfides is finally collected into the existing hot air tail pipe 10 of the blast furnace through the desorption gas branch pipes 9. Then, the desorption gas is conveyed into the blast furnace through a plurality of hot air branch pipes 11 connected with the hot air tail pipe 10 for combustion. After combustion in the blast furnace, 85% of the sulfides in the desorption gas rich in high-concentration sulfides are transferred into the slag, and the remaining small amount of sulfides are transferred into the blast furnace gas. The blast furnace gas is introduced into the adsorption desulfurization towers 1 for adsorption and desulfurization treatment. The purified blast furnace gas is sent into the purified blast furnace gas pipe network 17.

[0072] The method for treating the desorption gas of the blast furnace gas desulfurization has the following characteristics and advantages:

[0073] The method for treating desorption gas of blast furnace gas desulfurization returns the desorption gas containing high-concentration sulfides to the blast furnace for combustion, and most of the sulfides contained in the desorption gas after combustion enter the slag, and a small part of the remaining sulfides is transferred to the blast furnace gas, which can reach dynamic balance with the sulfides contained in the blast furnace gas to be purified, without adding other desorption gas treatment equipment, and has the advantages of simplifying the process, recycling, reducing the cost, avoiding secondary pollution and the like.

[0074] The above is only a specific embodiment of the present application, and is not intended to limit the scope of the present application. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principle of the present application shall fall within the scope of the present application.

Claims

1. A system for treating desulfurized and desorbed blast furnace gas, comprising multiple adsorption desulfurization towers, each of which is internally filled with an adsorbent material having adsorption capacity and capable of desorption and regeneration upon heating, characterized in that... The inlet of each of the adsorption desulfurization towers is connected to the blast furnace gas inlet pipe and the desorbed gas outlet pipe, respectively. The blast furnace gas inlet pipe and the desorbed gas outlet pipe are respectively connected to the blast furnace. The outlet of each of the adsorption desulfurization towers is connected to the clean gas outlet pipe and the regenerated desorbed gas inlet pipe, respectively. The clean gas outlet pipe is connected to the clean blast furnace gas pipeline network, and the regenerated desorbed gas inlet pipe is connected to the clean gas outlet pipe. The desorption gas outlet pipe includes a main desorption gas outlet pipe and multiple branch desorption gas outlet pipes. One end of each branch desorption gas outlet pipe is connected to the inlet of the corresponding adsorption desulfurization tower, and the other end of each branch desorption gas outlet pipe is connected to one end of the main desorption gas outlet pipe. The other end of the main desorption gas outlet pipe is connected to the desorption gas tail pipe. A gas compressor is installed on the main desorption gas outlet pipe. The desorption gas tailpipe is connected to the hot blast tailpipe via multiple desorption gas branch pipes. The hot blast tailpipe is connected to the blast furnace via multiple hot blast branch pipes. Each of the desorption gas branch pipes is evenly and spaced along the circumference of the hot blast tailpipe, and the number of the desorption gas branch pipes is adjusted according to the length of the hot blast tailpipe to ensure that the desorption gas is evenly mixed into the hot blast tailpipe. The desorption gas after desorption and desorption in each of the adsorption desulfurization towers flows sequentially through the desorption gas outlet pipe, the desorption gas tailpipe, multiple desorption gas branch pipes, the hot blast tailpipe, and multiple hot blast branch pipes into the blast furnace, so that the desorption gas introduced into the blast furnace can be evenly dispersed in the blast furnace. When each of the adsorption desulfurization towers is in the desorption regeneration state, the desorbed gas containing high concentration of sulfides is discharged into the blast furnace through the desorbed gas outlet pipe for combustion, so that most of the sulfides in the desorbed gas enter the slag, and the remaining small portion of sulfides are transferred to the blast furnace gas, so that the sulfides remaining after combustion and the sulfides contained in the blast furnace gas to be purified reach a dynamic balance.

2. The system for treating desulfurized and desorbed blast furnace gas as described in claim 1, characterized in that, The desorption gas outlet main pipe is equipped with a blind valve and a butterfly valve.

3. The system for treating desulfurized and desorbed blast furnace gas as described in claim 1, characterized in that, The desorption gas outlet main pipe is equipped with a quick-cut valve, which is connected to a combustible gas detection instrument.

4. The system for treating desulfurized and desorbed blast furnace gas as described in claim 1, characterized in that, The blast furnace gas inlet pipe includes a main blast furnace gas inlet pipe and multiple branch blast furnace gas inlet pipes. One end of each branch blast furnace gas inlet pipe is connected to the inlet of the corresponding adsorption desulfurization tower, and the other end of each branch blast furnace gas inlet pipe is connected to one end of the main blast furnace gas inlet pipe. The other end of the main blast furnace gas inlet pipe is through which blast furnace gas to be purified is introduced.

5. The system for treating desulfurized and desorbed blast furnace gas as described in claim 1, characterized in that, The clean coal gas outlet pipe includes a clean coal gas outlet main pipe and multiple clean coal gas outlet branch pipes. One end of each clean coal gas outlet branch pipe is connected to the outlet of the corresponding adsorption desulfurization tower, and the other end of each clean coal gas outlet branch pipe is connected to one end of the clean coal gas outlet main pipe. The other end of the clean coal gas outlet main pipe is connected to the clean blast furnace gas pipeline network.

6. The system for treating desulfurized and desorbed blast furnace gas as described in claim 5, characterized in that, The regenerated desorption gas inlet pipe includes a main regenerated desorption gas inlet pipe and multiple branch regenerated desorption gas inlet pipes. One end of each branch regenerated desorption gas inlet pipe is connected to the outlet of the corresponding adsorption desulfurization tower. One end of each branch regenerated desorption gas inlet pipe is connected to one end of the main regenerated desorption gas inlet pipe, and the other end of the main regenerated desorption gas inlet pipe is connected to the clean coal gas outlet pipe.

7. The system for treating desulfurized and desorbed blast furnace gas as described in claim 6, characterized in that, A heater is installed on the regenerated desorption gas inlet main pipe.

8. A method for treating desulfurized and desorbed blast furnace gas, comprising adopting the system for treating desulfurized and desorbed blast furnace gas as described in any one of claims 1 to 7, characterized in that, The method for treating blast furnace gas desulfurization and desorption gas includes the following steps: Step S1: The blast furnace gas to be purified is introduced into multiple adsorption desulfurization towers to adsorb and remove sulfides and impurities in the blast furnace gas. Step S2: After the adsorption material in the adsorption desulfurization tower reaches the preset saturation, the clean blast furnace gas generated by each adsorption desulfurization tower is heated and returned to the adsorption desulfurization tower. Step S3: The sulfides and impurities adsorbed by the adsorption materials in each of the adsorption desulfurization towers are desorbed into the desorbed gas; Step S4: The desorbed gas from each of the adsorption desulfurization towers is transported to a blast furnace for combustion.

9. The method for treating desulfurized and desorbed blast furnace gas as described in claim 8, characterized in that, In step S1, the clean blast furnace gas is transported to the clean blast furnace gas pipeline network.

10. The method for treating desulfurized and desorbed blast furnace gas as described in claim 8, characterized in that, Each of the adsorption desulfurization towers serves as a backup adsorption desulfurization tower. During the regeneration state of the adsorption desulfurization tower, the backup adsorption desulfurization tower performs adsorption desulfurization operations.

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