Method and system for preventing graphite from forming on the top of coke oven carbonization chamber and the outlet of furnace top riser

Abstract

The present invention relates to the technical field of coke ovens, and in particular discloses a method and system for preventing graphite from forming on the top of a coke oven carbonization chamber and at an outlet of a riser on the top of the coke oven, comprising a coke oven carbonization chamber, a coke oven carbonization chamber top, a riser, a bridge pipe, a waste heat recovery pipe group and a water seal cover, wherein the bottom end of the waste heat recovery pipe group is inserted into the coke oven carbonization chamber top and is flush with the bottom surface of the coke oven carbonization chamber top, and the top of the waste heat recovery pipe group extends upward and passes through the root of the riser, the middle of the riser and the top of the riser in sequence. Compared with the traditional technology, the technical solution breaks through the traditional cognition by extending the waste heat recovery pipe group into the coke oven carbonization chamber top, avoids the coking problem in the riser between the coke oven carbonization chamber top and the water seal cover, and improves the production efficiency of the coke oven.

Description

Technical Field

[0001] The invention relates to the technical field of coke ovens, and in particular to a method and a system for preventing graphite from forming at the top of a coke oven carbonization chamber and at an outlet of a furnace top riser. Background Art

[0002] Coal coking coke oven is usually composed of multiple combustion chambers and carbonization chambers arranged in sequence, which are a complete set of equipment for heating coking coal insulated from air (coal distillation). The coking process is the process of producing coke and generating a large amount of raw coal gas. A certain space is left on the top of the carbonization chamber where coking coal is loaded. This is the residence and flow channel for the raw coal gas output. One or two raw coal gas outlets, i.e., furnace mouths, are arranged on the top of each carbonization chamber. The furnace mouth is provided with a riser pipe seat socket, a riser pipe, a riser three-way bridge pipe and a riser water seal cover as an integral device. The riser pipe seat is inserted into the pipe seat socket, and the bend of the riser three-way bridge pipe is inserted into the gas collecting pipe socket to realize the export of raw coal gas.

[0003] When the top of the carbonization chamber and its outflow channel are above 850℃, the raw coal gas from the dry distillation of coking coal begins to crack. The cracking products are carbon, small molecular hydrocarbons and hydrogen. The carbon is graphite (commonly known as coke). Therefore, in order to prevent the raw coal gas from cracking into graphite, the top of the carbonization chamber in the coke oven production process needs to be controlled below 850℃. This is inconsistent with the process requirement that coking coal can only be coked at 1050℃. Germany has explored the temperature control of the top of the carbonization chamber, but has not proposed how to solve the problem of raw coal gas coking after the temperature of the top of the carbonization chamber is increased. Japan controlled the temperature of the top of the combustion chamber to 1250℃, and later proposed a method of injecting water vapor at the top of the carbonization chamber, but its anti-coking technology has not been implemented in engineering.

[0004] Traditionally, it is believed that the top of the carbonization chamber of the coke oven and the outlet of the furnace top riser are the inside of the coke oven. The heat of the high-temperature raw coal gas here is the heat inside the coke oven. If waste heat recovery is carried out here, it is the recovery of the heat of the coke oven and the transfer of heat from the coke oven heating system. It requires increased fuel consumption and will reduce the efficiency of the coke oven. However, in the actual production process, the cooling process is the process of opening the furnace cover for charring. The open furnace charring in this process, that is, burning the graphite formed in the dry flow process, wastes the coal coke and its combustion heat, and causes the open charring process to emit VOC. Obviously, this will increase the energy consumption of the entire coke oven, and this consumption also increases environmental pollution. In general, it still reduces the efficiency of the coke oven and is not environmentally friendly and clean production.

[0005] In particular, considering that the coke maturity is controlled by the carbonization chamber coal cake center temperature of 1000±50℃, it is considered that the coal cake center temperature of 1050℃ is the standard for coke maturity, and the top surface of the coke oven carbonization chamber is controlled at 800±50℃, and even below 850℃. In this way, the coke below 850℃ is not mature. The cold furnace coking process is also the process of cooking coke. If the cold furnace is not used, the quality of coke will be reduced. Obviously, after the waste heat is recovered at the top of the carbonization chamber and the outlet of the furnace top riser, the upper and lower temperatures of the carbonization chamber can be uniformly controlled at 1050℃, or 850℃≤the top temperature of the carbonization chamber≤1050℃, which will eliminate the cold furnace process and realize the closed coking clean production process.

[0006] There are two reasons for the coking of raw coal gas. One is the cracking of raw coal gas at 850℃ and above to generate carbon (graphite, coke) + hydrogen. The other is the condensation of raw coal gas at 450℃ and below in the mixed state of coking coal dust (ash) brought out when the raw coal gas is distilled, forming layered coking. Obviously, the temperature of raw coal gas is the fundamental factor causing coking. The method to prevent coking in the coke oven is to control the top temperature of the combustion chamber, and then control the top temperature of the carbonization chamber below 850℃, and to recover the sensible heat and waste heat of raw coal gas to control the riser raw coal gas outlet temperature above 450℃.

[0007] The heat energy of raw gas from coke ovens accounts for 36% of the total heat energy expenditure of coke ovens. Existing coke ovens save energy by recovering the sensible heat and waste heat of raw gas. However, the actual waste heat recovery of the rising pipe for recovering the sensible heat and waste heat of raw gas from coke ovens is currently limited to the position from the flange on the pipe seat of the rising pipe to the lower flange of the three-way bridge pipe, and the internal plug-in type does not control the heat recovery problem from the upper flange to the lower flange of the bridge pipe three-way. Therefore, the existing technology does not control the temperature of the top of the carbonization chamber of the coke oven and the furnace mouth at the raw gas outlet on the furnace top and under the water seal cover of the rising pipe, which also causes coking at this position. Coking at this position will block the outflow channel of raw gas, causing the furnace pressure to be too high and the raw gas to leak out, which will cause explosions, fires and other accidents, bringing serious hidden dangers to production safety. Moreover, when burning and cleaning coke, VOC emissions are caused, equipment damage caused by cleaning coke is caused, labor intensity is increased and production safety hazards are hidden dangers, and the productivity of coke ovens is reduced.

[0008] Therefore, it is necessary to propose a method and system for preventing graphite from forming at the top of the carbonization chamber and the outlet of the furnace top riser, so as to reduce the coking problem in the area between the top of the carbonization chamber and the outlet of the furnace top riser and the water seal cover. Under the premise that the clean production of coke ovens requires ultra-low emissions or zero emissions, recovering waste heat at the top of the carbonization chamber and the outlet of the furnace top riser is also one of the effective means to achieve clean production technology of coke ovens, and can also improve the production efficiency of coke ovens, achieve great energy saving and emission reduction benefits and protect the environment. Summary of the invention

[0009] The purpose of the present invention is to solve the problems in the prior art, and a method and system for preventing graphite from forming on the top of a coke oven carbonization chamber and at the outlet of a furnace top riser are provided.

[0010] The technical method of the present invention is:

[0011] A method for preventing graphite from accumulating on the top of a carbonization chamber and at the outlet of a riser of a coke oven, the method comprising: using a waste heat recovery method to control the temperature of raw gas at the top of the carbonization chamber, at the bottom of the riser at the top of the carbonization chamber, and at the root of the riser, and specifically comprising a method for controlling the temperature of raw gas at the top of the carbonization chamber by using the waste heat recovery method, characterized in that a waste heat recovery pipe or a pipe group is arranged at the top of the carbonization chamber, which crosses the longitudinal direction of the carbonization chamber, i.e., the longitudinal direction between the coal side and the coke side of the coke oven, and the heat exchange area and the heat recovery area of ​​the waste heat recovery pipe or the pipe group are used. The method of controlling the top temperature of the carbonization chamber by heat; the raw gas temperature at the bottom of the rising pipe at the top of the carbonization chamber and the root of the rising pipe is ≤850°C, preferably ≤800°C, characterized in that a waste heat recovery pipe or pipe group is arranged at the bottom of the rising pipe at the top of the carbonization chamber and the raw gas flow place at the root of the rising pipe, and the heat exchange area and heat extraction of the waste heat recovery pipe or pipe group are used to control the temperature of this part to be greater than 450°C and less than or equal to 850°C, preferably greater than 500°C and less than or equal to 800°C; The waste heat recovery pipe or pipe group is characterized in that a plurality of heat extraction pipe groups are connected in parallel to form a waste heat recovery pipe group, and the plurality of heat extraction pipe groups are connected in parallel to the inlet and outlet pipes of the working medium in the waste heat return pipe; the method for preventing graphite from forming at the top of the carbonization chamber and the outlet of the riser of the coke oven is characterized in that the temperature control method of the raw gas at the top of the carbonization chamber, the bottom of the riser at the top of the carbonization chamber and the root of the riser can be used independently; the method for preventing graphite from forming at the top of the carbonization chamber and the outlet of the riser of the coke oven is characterized in that the working medium in the waste heat return pipe in the waste heat recovery pipe group is water and / or water vapor, and the inlet and outlet pipes are connected to the waste heat recovery system to produce superheated and / or saturated steam through the working medium, and the produced steam can be used to drive the machine to do work or be used as a production heat source, or be used as a production heat source after doing work; the method for preventing graphite from forming at the top of the carbonization chamber and the outlet of the riser of the coke oven is characterized in that the temperature of the furnace wall on the carbonization chamber side is controlled not to exceed 1450°C, and preferably the temperature of the furnace wall on the carbonization chamber side is controlled not to exceed 1250°C.

[0012] The present invention also provides a graphite-prevention system at the top of a coke oven carbonization chamber and at the outlet of a riser, including any one of the above-mentioned graphite-prevention methods at the top of a coke oven carbonization chamber and at the outlet of a riser, including: a coke oven carbonization chamber, a coke oven carbonization chamber top, a riser, a bridge pipe, a waste heat recovery pipe group at the top of the carbonization chamber, a waste heat recovery pipe group at the raw gas outlet at the bottom of the riser at the top of the carbonization chamber, and a waste heat recovery pipe group at the raw gas temperature at the root of the riser and a water seal cover, wherein the waste heat recovery pipe group crosses the space at the top of the carbonization chamber; and the bottom of the riser at the top of the carbonization chamber. The waste heat recovery pipe group at the raw gas outlet, the raw gas temperature waste heat recovery pipe group at the root of the riser extends to the top of the carbonization chamber, that is, the bottom end of the waste heat recovery pipe is inserted into the top of the coke oven carbonization chamber and is flush with the bottom surface of the top of the coke oven carbonization chamber, and the top of the waste heat recovery pipe group extends upward and passes through the root of the riser, the middle of the riser and the top of the riser in turn; each waste heat recovery pipe group and its respective inlet and outlet pipes are connected in parallel to the inlet and outlet pipe systems of their respective systems, and then are combined into one system or become their respective systems respectively.

[0013] Furthermore, it also includes a steam drum and a water pump, the water inlet of the steam drum is connected to the water outlet of the waste heat recovery pipe group, the water pump is connected to the water outlet of the steam drum and the water inlet of the waste heat recovery pipe group at the same time, the gas outlet of the steam drum is connected to the steam inlet of the waste heat recovery pipe group, and the waste heat recovery pipe group is connected to a steam outlet, and the steam can be discharged to the waste heat recovery pipe group through the steam outlet.

[0014] Furthermore, the top of the coke oven carbonization chamber is connected to the top of the coke oven carbonization chamber, the riser is connected to the top of the coke oven carbonization chamber top, the bridge pipe is connected to the top of the riser through a flange, the top flange of the bridge pipe is connected to the riser top pipe, and the water seal cover is connected to the riser top pipe flange.

[0015] Furthermore, a diameter expansion pipe is provided at the bottom end of the waste heat recovery pipe group, and the diameter expansion pipe sleeve is arranged on the outer side of the bottom end of the waste heat recovery device.

[0016] Furthermore, the bottom end of the waste heat recovery pipe group is connected with an annular connecting pipe.

[0017] Furthermore, the outer surface of the waste heat recovery pipe group is made of metal, and the outer surface of the waste heat recovery pipe group is covered with a ceramic layer to isolate the high-temperature raw coal gas from the metal surface of the heat exchange tube to prevent high-temperature corrosion of the high-temperature raw coal gas. The ceramic layer ensures that the heat exchange surface temperature of the heat exchanger is higher than 450°C, preferably higher than 500°C to prevent condensation of high-temperature raw coal gas and prevent the formation of bonding and coking. The bottom end of the waste heat recovery pipe group is connected with a reducer, and the reducer can increase the heat exchange area and enhance the heat exchange.

[0018] The method and system for preventing graphite from forming at the top of the carbonization chamber of the coke oven and the outlet of the furnace top riser of the present invention, on the one hand, a waste heat recovery pipe group is arranged between the furnace mouth at the top of the coke oven carbonization chamber and the outlet of the furnace top riser and the bottom of the water seal cover of the riser, and the temperature of this area can be timely and accurately controlled by the waste heat recovery pipe group, so that the temperature of the top of the coke oven carbonization chamber in this area is lower than 850°C, and the temperature at the water seal cover is higher than 450°C, thereby avoiding the coking problem in this area. On the other hand, the waste heat recovery pipe group in the existing coke oven is strictly limited to the position above the top of the coke oven carbonization chamber, because in the traditional understanding, when the waste heat recovery pipe group at the riser is lower than the flange surface at the bottom of the riser, it is considered that the waste heat recovery pipe group at the riser is The heat recovery pipe group not only recovers the sensible waste heat of the raw coal gas, but also recovers the heat in the carbonization chamber, which is equivalent to taking away the heat from the coke oven combustion chamber, thus affecting the normal production. In fact, the heat exceeding 850°C at the top of the carbonization chamber is redundant heat for the coke oven production. Therefore, installing a waste heat recovery pipe group in the top of the coke oven carbonization chamber and installing a waste heat recovery pipe group in the riser can accurately and timely control the heat and avoid coking. Compared with the traditional technology, this technical solution breaks through the traditional cognition by extending the waste heat recovery pipe group to the top of the coke oven carbonization chamber, avoiding the coking problem in the riser between the top of the coke oven carbonization chamber and the water seal cover, and improving the production efficiency of the coke oven. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 For reference to the structure of the first embodiment of the present invention Figure 1 ;

[0020] Figure 2 For reference to the structure of the first embodiment of the present invention Figure 2 ;

[0021] Figure 3 The top structure of the coke oven carbonization chamber in the first embodiment of the present invention is referenced Figure 1 ;

[0022] Figure 4 The top structure of the coke oven carbonization chamber in the first embodiment of the present invention is referenced Figure 2 ;

[0023] Figure 5 This is a structural reference diagram of Embodiment 2 of the present invention;

[0024] Figure 6 The top structure of the coke oven carbonization chamber in the second embodiment of the present invention is referenced Figure 1 ;

[0025] Figure 7 The top structure of the coke oven carbonization chamber in the second embodiment of the present invention is referenced Figure 2 ;

[0026] Figure 8 For reference to the structure of the third embodiment of the present invention Figure 1;

[0027] Fig. 9 The carbonization chamber top structure of the coke oven in the fourth embodiment of the present invention is referenced Figure 1 ;

[0028] Fig.10 The carbonization chamber top structure of the coke oven in the fourth embodiment of the present invention is referenced Figure 2 ;

[0029] Fig.11 The carbonization chamber top structure of the coke oven in the fourth embodiment of the present invention is referenced Figure 3 ;

[0030] Fig.12 This is a schematic diagram of the system of the present invention.

[0031] Figure numerals: 1. coke oven carbonization chamber; 2. coke oven carbonization chamber top; 3. expansion pipe; 4. riser pipe; 5. bridge pipe; 6. waste heat recovery pipe group; 7. water seal cover; 8. annular connecting pipe; 9. reducing pipe; 10. waste heat recovery pipe group at the top of the carbonization chamber. DETAILED DESCRIPTION

[0032] A method for preventing graphite from forming on the top of a carbonization chamber and at the outlet of a riser of a coke oven, the method comprising: using a waste heat recovery method to control the temperature of raw gas at the top of the carbonization chamber, at the bottom of the riser at the top of the carbonization chamber, and at the root of the riser, and specifically comprising a method for controlling the temperature of raw gas at the top of the carbonization chamber by using the waste heat recovery method, wherein a waste heat recovery pipe or a pipe group is arranged at the top of the carbonization chamber, which crosses the longitudinal direction of the carbonization chamber, i.e., the longitudinal direction between the coal side and the coke side of the coke oven, and the heat exchange area and heat intake of the waste heat recovery pipe or the pipe group are used to control the temperature of the top of the carbonization chamber. The temperature of the raw gas at the bottom of the raw gas outlet of the top riser of the carbonization chamber and the root of the riser is ≤850°C, preferably ≤800°C. The purpose of this selection is to make the raw gas leave the cracking temperature of the macromolecular hydrocarbons. The raw gas outlet at the bottom of the top riser of the carbonization chamber and the raw gas flow area at the root of the riser are prone to coking, and it is troublesome to remove the coke. A waste heat recovery pipe or pipe group is set at this place to take out the heat above 850°C or 800°C. The heat exchange area and the heat extraction amount of the waste heat recovery pipe or pipe group are used to control the heat extraction. The temperature of the part is controlled to be greater than 450°C and less than or equal to 850°C, preferably greater than 500°C and less than or equal to 800°C; for the waste heat recovery at the top of the carbonization chamber and the waste heat recovery pipe or pipe group at the furnace mouth of the carbonization chamber top and the riser outlet, multiple groups of heat extraction pipe groups are connected in parallel to form a waste heat recovery pipe group, and the multiple groups of heat extraction pipe groups are connected in parallel to the inlet and outlet pipes of the working medium in the waste heat return pipe; the graphite prevention method for the top of the carbonization chamber and the riser outlet of the coke oven, the top of the carbonization chamber, the carbonization chamber The method for controlling the temperature of the raw gas at the raw gas outlet at the bottom of the top riser and at the root of the riser can be used independently; the method for preventing graphite from accumulating at the top of the coke oven carbonization chamber and the riser outlet, the working medium in the waste heat return pipe in the waste heat recovery pipe group is water and / or water vapor, and the inlet and outlet pipes are connected to the waste heat recovery system to produce superheated and / or saturated steam through the working medium. The produced steam can be used to drive the machine to do work or be used as a production heat source, or be used as a production heat source after doing work, so that the cascade utilization of high-temperature raw gas can be achieved.

[0033] The graphite-prevention method at the top of the carbonization chamber and the outlet of the riser of the coke oven controls the temperature of the furnace wall of the carbonization chamber to not exceed 1450° C., preferably, the temperature of the furnace wall of the carbonization chamber is controlled not to exceed 1250° C. Such a high temperature can prepare for the future increase in the productivity of the coke oven.

[0034] In order to make the technical means, technical features, invention objectives and technical effects achieved by the present invention easy to understand, the present invention is further explained below with reference to specific illustrations.

[0035] Embodiment 1:

[0036] like Figure 1-Figure 4 As shown, this embodiment provides a method for preventing graphite from forming on the top of the carbonization chamber and the outlet of the riser of a coke oven, which specifically includes the following steps:

[0037] Install a heat extraction pipe group, which is installed at the top of the carbonization chamber and the riser port at the top of the carbonization chamber. Control the power of the heat extraction pipe group to cool the raw gas temperature at the top of the carbonization chamber and the riser outlet of the top of the carbonization chamber to below 850°C, and make the temperature of the area between the top of the coke oven carbonization chamber and the root of the riser not exceed 850°C, preferably reduced to 830°C and below. Connect multiple groups of heat extraction pipe groups in parallel to form a waste heat recovery pipe group, and connect the multiple groups of heat extraction pipe groups in parallel to the inlet and outlet pipes of the working medium in the waste heat return pipe. The waste heat recovery pipe group runs through the entire carbonization chamber, and the temperature between the bridge pipe and the riser and the water seal cover is controlled to be not less than 450°C, preferably reduced to 480°C and above. Control the temperature of the furnace wall on the carbonization chamber side to not exceed 1450°C. Preferably, when the temperature of the furnace wall on the carbonization chamber side is controlled to not exceed 1250°C, the temperature control method at the outlet of the riser on the top of the carbonization chamber can be used independently.

[0038] The waste heat recovery working fluid in the waste heat recovery pipe group is water or water vapor. The inlet and outlet pipes are connected to the waste heat recovery system to produce steam. The steam can be used to drive the machine to do work or produce heat source, or the steam can be used to produce heat source after doing work, thereby realizing the cascade utilization of high-quality waste heat of raw coal gas. The preferred working fluid is water or saturated steam.

[0039] A graphite-prevention system for the top of a coke oven carbonization chamber and at the outlet of a riser, comprising any one of the above-mentioned graphite-prevention methods for the top of a coke oven carbonization chamber and at the outlet of a riser, comprising: a coke oven carbonization chamber, a coke oven carbonization chamber top, a riser, a bridge pipe, a waste heat recovery pipe group and a water seal cover, the waste heat recovery pipe group comprising a waste heat recovery pipe group at the top of the carbonization chamber, a waste heat recovery pipe group at the raw gas outlet at the bottom of the riser at the top of the carbonization chamber, and a waste heat recovery pipe group at the raw gas temperature at the root of the riser, the waste heat recovery pipe group crossing the space at the top of the carbonization chamber; the waste heat recovery pipe group at the raw gas outlet at the bottom of the riser at the top of the carbonization chamber The waste heat recovery pipe group, the raw gas temperature waste heat recovery pipe group at the root of the riser extends to the top of the carbonization chamber, that is, the bottom end of the waste heat recovery pipe group is inserted into the top of the coke oven carbonization chamber and is flush with the bottom surface of the top of the coke oven carbonization chamber, and the top of the waste heat recovery pipe group extends upward and passes through the root of the riser, the middle of the riser and the top of the riser in turn. The waste heat recovery pipe group and the inlet and outlet pipes are connected in parallel to the inlet and outlet pipe systems of their respective systems, and then are combined into one system or become their respective systems respectively. The sleeve type connection, the core pipe is the inlet pipe, and the outer sleeve is the outlet pipe.

[0040] Preferably, the waste heat recovery pipe group is inserted to a position one inserter tube diameter above the top and bottom surfaces of the coke oven carbonization chamber.

[0041] Preferably, it also includes a steam drum and a water pump, the water inlet of the steam drum is connected with the water outlet of the waste heat recovery pipe group, the water pump is simultaneously connected with the water outlet of the steam drum and the water inlet of the waste heat recovery pipe group, the gas outlet of the steam drum is connected with the steam inlet of the waste heat recovery pipe group, the waste heat recovery pipe group is connected with a steam outlet, and the steam can be discharged to the waste heat recovery pipe group through the steam outlet, a heat extraction pipe group is laid on the top of the carbonization chamber, and a heat extraction pipe group is also laid at the riser pipe mouth at the top of the carbonization chamber, the steam drum can pass the steam into the heat extraction pipe group at the top of the carbonization chamber and the heat extraction pipe group at the riser pipe mouth through the steam inlet, which can play a role in cooling the temperature in the furnace after heat exchange, and then the superheated steam is discharged through the steam outlet, and at the same time, the water in the steam drum will also be discharged into the heat extraction pipe group through the water inlet of the heat extraction pipe group by the water pump, cooperate with the steam to achieve cooling, and then flow back to the steam drum through the water outlet of the heat extraction pipe group, so as to achieve cooling in a cycle.

[0042] Preferably, the top of the coke oven carbonization chamber is connected to the top of the coke oven carbonization chamber, the riser is connected to the top of the coke oven carbonization chamber top, the bridge pipe is connected to the top of the riser through a flange, the top flange of the bridge pipe is connected to the riser top pipe, and the water seal cover is connected to the riser top pipe flange.

[0043] Preferably, an expansion pipe is provided at the bottom end of the waste heat recovery pipe group, and the expansion pipe sleeve is arranged on the outer side of the bottom end of the waste heat recovery device.

[0044] Preferably, the bottom end of the waste heat recovery pipe group is connected with an annular connecting pipe.

[0045] Preferably, the outer surface of the waste heat recovery pipe group is made of metal, and the outer surface of the waste heat recovery pipe group is covered with a ceramic layer to isolate the high-temperature raw coal gas from the metal surface of the heat exchange tube to prevent high-temperature corrosion of the high-temperature raw coal gas. The ceramic layer ensures that the heat exchange surface temperature of the heat exchanger is higher than 450°C, preferably higher than 500°C to prevent condensation of high-temperature raw coal gas and prevent the formation of bonding and coking.

[0046] Preferably, the bottom end of the waste heat recovery pipe group is connected to a reducer, and the reducer can increase the heat extraction and heat exchange area and enhance the heat extraction and heat exchange.

[0047] The outer tube material of the waste heat recovery pipe group at the top of the coke oven carbonization chamber is A310S stainless steel seamless pipe; the working medium in the waste heat return pipe of the waste heat recovery pipe group at the top of the coke oven carbonization chamber and the riser outlet is water and water vapor, preferably saturated steam; the process flow of the multiple groups of heat extraction pipe groups is that the system feeds water into the steam drum, the water supply is controlled by the steam drum liquid level, the circulating water at the bottom of the steam drum enters the forced circulation water pump inlet along the pipeline, the circulating water pump outlet pipeline sends water to the riser waste heat recovery device inlet, and after the raw coal gas and the heat exchanger heat transfer, it is merged into the outlet pipeline from the heat exchanger outlet, The outlet pipe is sent back to the steam drum for steam-water separation, and saturated steam is separated from the top. The saturated steam is sent along the steam outlet pipe to the top of the carbonization chamber and the outlet of the riser at the top of the carbonization chamber, and the heat extraction pipe group is inserted respectively. The saturated steam is heated by the waste heat recovery pipe group at the top of the carbonization chamber and the outlet of the riser at the top of the carbonization chamber, and then collected to the superheated steam outlet pipe for external delivery. The working medium in the waste heat return pipe of the waste heat recovery pipe group at the top of the carbonization chamber and the outlet of the riser of the coke oven is water and water vapor, preferably saturated steam, and the material of the heat extraction pipe group is 0Cr25Ni20.

[0048] Embodiment 2:

[0049] The same points as those in the first embodiment are not described in detail here. The difference between the present embodiment and the first embodiment is that Figure 5-Figure 7 As shown, the bottom end of the waste heat recovery pipe group 6 is provided with an expansion pipe 3, and the expansion pipe 3 is sleeved on the outside of the bottom end of the waste heat recovery device. The expansion pipe 3 can increase the diameter of the waste heat recovery pipe group 6, thereby increasing the heating area and improving the heat exchange efficiency. The expansion pipe 3 and the waste heat recovery pipe group 6 can be welded, threaded, or integrally formed by mold injection.

[0050] Embodiment three:

[0051] The same points as those in the first embodiment are not described in detail here. The difference between the present embodiment and the first embodiment is that Figure 8 As shown, the bottom end of the waste heat recovery pipe group 6 is connected with an annular connecting pipe 8.

[0052] Embodiment 4:

[0053] The same points as those in the first embodiment are not described in detail here. The difference between the present embodiment and the first embodiment is that Figure 9-11 The bottom end of the waste heat recovery pipe group 6 is connected to a reducer 9, and the reducer 9 can increase the heat extraction and heat exchange area and enhance the heat extraction and heat exchange.

[0054] The method and system for preventing graphite from forming at the top of the carbonization chamber of the coke oven and the outlet of the furnace top riser of the present invention, on the one hand, a waste heat recovery pipe group 6 is arranged between the outlet furnace mouth of the riser 4 at the top 2 of the coke oven carbonization chamber and the bottom of the water seal cover 7 of the riser 4, and the temperature of this area can be timely and accurately controlled by the waste heat recovery pipe group 6, so that the temperature of the top 2 of the coke oven carbonization chamber in this area is lower than 850°C, and the temperature at the water seal cover 7 is higher than 450°C, thereby avoiding the coking problem in this area. On the other hand, the waste heat recovery pipe group 6 in the existing coke oven is strictly limited to the position above the top 2 of the coke oven carbonization chamber, because in the traditional understanding, when the waste heat recovery pipe group 6 at the riser 4 is lower than the flange surface at the bottom of the riser 4, it is considered that the waste heat recovery pipe group 6 at the riser 4 is lower than the flange surface at the bottom of the riser 4. The heat recovery pipe group 6 not only recovers the sensible waste heat of the raw coal gas, but also recovers the heat in the carbonization chamber, which is equivalent to taking away the heat from the coke oven combustion chamber, thereby affecting normal production. In fact, the heat exceeding 850°C at the top of the carbonization chamber is redundant heat for coke oven production. Therefore, installing the waste heat recovery pipe group 6 in the top 2 of the coke oven carbonization chamber and installing the waste heat recovery pipe group 6 in the riser 4 can accurately and timely control the heat and avoid coking. Compared with traditional technology, this technical solution breaks through traditional cognition by extending the waste heat recovery pipe group 6 into the top of the coke oven carbonization chamber, avoiding the coking problem in the riser 4 between the top 2 of the coke oven carbonization chamber and the water seal cover 7, thereby improving the production efficiency of the coke oven.

[0055] The problem of raw gas coking is solved by a non-mechanical method, without mechanical damage, mechanical consumption, or mechanical trauma, and the production environment is cleaner. A larger amount of waste heat can be recovered, and the cracking heat generated by the high-temperature cracking of the raw gas is safely used for raw gas temperature control. It is more flexible and safer, and all heat used for graphite formation is recovered as much as possible, and the energy-saving and environmental protection benefits are significantly improved. The labor intensity of maintenance of the riser 4 pipes is greatly reduced, and the working environment of the workers is significantly improved, which reduces the graphite formation caused by the cracking of raw gas, increases the yield of coal tar from raw gas, and saves resources. The present invention improves the essential safety technology of the coking production process.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of implementation of the present invention. That is, all equivalent changes and modifications made according to the content of the patent application scope of the present invention should belong to the technical scope of the present invention.

Claims

1. A method for preventing graphite from forming at the top of a coke oven carbonization chamber and at the outlet of a riser. A waste heat recovery pipe group is arranged at the top of the carbonization chamber, at the bottom of the riser at the top of the carbonization chamber, at the outlet of raw gas, and at the root of the riser. The waste heat recovery pipe group reduces the temperature of the top of the carbonization chamber, at the bottom of the riser at the top of the carbonization chamber, and at the root of the riser by heat exchange, so that the temperature is lower than the cracking temperature of raw gas. The method is characterized in that A waste heat recovery pipe group is arranged at the top of the carbonization chamber across the top of the carbonization chamber, and the heat intake is controlled by adjusting the heat exchange area of ​​the waste heat recovery pipe group to control the heat intake, thereby adjusting the temperature at the top of the carbonization chamber to be less than or equal to 850°C; a waste heat recovery pipe group is arranged at the raw gas outlet at the bottom of the riser at the top of the carbonization chamber and at the raw gas circulation point at the root of the riser, and the heat exchange area of ​​the waste heat recovery pipe group is adjusted to control the heat intake, thereby making the temperature at the raw gas outlet at the bottom of the riser at the top of the carbonization chamber and at the root of the riser lower than the graphite temperature of the raw gas cracking knot, and the temperature at the raw gas outlet at the bottom of the riser at the top of the carbonization chamber and at the root of the riser is greater than 450°C and less than or equal to 850°C, and each waste heat recovery pipe group is connected in parallel to the inlet and outlet pipes of the working medium of the waste heat recovery pipe group.

2. The method for preventing graphite from forming on the top of the coke oven carbonization chamber and at the outlet of the riser according to claim 1, characterized in that: The methods for controlling the raw gas temperature at the top of the carbonization chamber, the raw gas outlet at the bottom of the riser at the top of the carbonization chamber, and the root of the riser can be used independently.

3. The method for preventing graphite from forming on the top of the carbonization chamber and the outlet of the riser of a coke oven according to claim 1, characterized in that: The working medium in the waste heat recovery pipe group is water and / or water vapor. After the inlet and outlet pipes are connected to the waste heat recovery system, superheated and / or saturated steam is produced through the working medium. The produced steam can be used to drive the machine to do work or be used as a heat source, or be used as a heat source after doing work.

4. The method for preventing graphite from forming on the top of the carbonization chamber and the outlet of the riser of a coke oven according to claim 1, characterized in that: The temperature of the furnace wall on the carbonization chamber side is controlled not to exceed 1450℃.

5. A graphite-prevention system for the top of a coke oven carbonization chamber and at an outlet of a riser, used for implementing the graphite-prevention method for the top of a coke oven carbonization chamber and at an outlet of a riser as claimed in any one of claims 1 to 4, characterized in that: include: A coke oven carbonization chamber (1), a coke oven carbonization chamber top (2), an ascending pipe (4), a bridge pipe (5), a waste heat recovery pipe group (10) at the top of the carbonization chamber, a waste heat recovery pipe group (6) at the bottom of the carbonization chamber top ascending pipe and at the root of the riser, and a water seal cover (7), wherein the waste heat recovery pipe group (10) at the top of the carbonization chamber crosses the space at the top of the carbonization chamber (2); the waste heat recovery pipe group (6) at the bottom of the carbonization chamber top ascending pipe and at the root of the riser extends toward the top of the carbonization chamber (2), i.e., the waste heat recovery pipe group (6) at the bottom of the carbonization chamber top ascending pipe and at the root of the riser extends toward the top of the carbonization chamber (2). The bottom end of the raw gas temperature waste heat recovery pipe group (6) at the gas outlet and the root of the riser is inserted into the coke oven carbonization chamber top (2) and is flush with the bottom surface of the coke oven carbonization chamber top (2), and the top of the raw gas temperature waste heat recovery pipe group (6) at the raw gas outlet and the root of the riser at the top of the carbonization chamber passes through the root of the riser (4), the middle of the riser (4) and the top of the riser (4) in sequence; each waste heat recovery pipe group and its own inlet and outlet pipes are connected in parallel to the inlet and outlet pipe systems of their own systems, and then are combined into one system or become their own systems respectively.

6. The graphite-prevention system at the top of the coke oven carbonization chamber and the outlet of the furnace top riser according to claim 5, characterized in that: The coke oven carbonization chamber top (2) is connected to the top of the coke oven carbonization chamber (1), the riser (4) is connected to the top of the coke oven carbonization chamber top (2), the bridge pipe (5) is connected to the top of the riser (4) via a flange, the top flange of the bridge pipe (5) is connected to the top pipe of the riser (4), and the water seal cover (7) is connected to the top pipe flange of the riser (4).

7. The graphite-prevention system at the top of the coke oven carbonization chamber and the outlet of the furnace top riser according to claim 5, characterized in that: An expansion pipe (3) is provided at the bottom end of the raw gas outlet at the bottom of the carbonization chamber top riser and the raw gas temperature waste heat recovery pipe group (6) at the root of the riser. The expansion pipe (3) is sleeved on the outer side of the bottom end of the raw gas outlet at the bottom of the carbonization chamber top riser and the raw gas temperature waste heat recovery pipe group (6) at the root of the riser.

8. The graphite-prevention system at the top of the coke oven carbonization chamber and the outlet of the furnace top riser according to claim 5, characterized in that: An annular connecting pipe (8) is connected to the bottom end of the raw gas outlet at the bottom of the riser at the top of the carbonization chamber and the raw gas temperature waste heat recovery pipe group (6) at the root of the riser.

9. The graphite-prevention system at the top of the coke oven carbonization chamber and the outlet of the furnace top riser according to claim 5, characterized in that: The rough coal gas temperature waste heat recovery pipe group (6) at the rough coal gas outlet at the bottom of the carbonization chamber top riser and at the root of the riser is made of metal, and the outer surface of the rough coal gas temperature waste heat recovery pipe group (6) at the rough coal gas outlet at the bottom of the carbonization chamber top riser and at the root of the riser is covered with a ceramic layer to isolate the high-temperature rough coal gas from the metal surface of the heat exchange pipe; the bottom end of the rough coal gas temperature waste heat recovery pipe group (6) at the rough coal gas outlet at the bottom of the carbonization chamber top riser and at the root of the riser is connected with a reducer (9), and the connection of the reducer (9) can increase the heat collection and heat exchange area, thereby strengthening the heat collection and heat exchange.

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