Phosphate-containing waste liquid and waste gas incineration treatment system

Abstract

The invention provides an incineration treatment system for waste liquid and waste gas containing phosphate. The incineration treatment system comprises an incinerator, a cooling sedimentation furnace and a denitration sedimentation furnace. The incinerator output end of the incinerator communicates with the cooling settling furnace input end of the cooling settling furnace, and second flue gas obtained after first heat exchange is conducted on the first flue gas is introduced into the cooling settling furnace; the cooling settling furnace output end of the cooling settling furnace is communicated with the denitration settling furnace input end of the denitration settling furnace, and fourth flue gas obtained after third heat exchange is conducted on the third flue gas is settled and then introduced into the denitration settling furnace; and the denitration settling furnace is used for carrying out denitration treatment on the fourth flue gas to obtain fifth flue gas, and sixth flue gas obtained by carrying out fourth heat exchange on the fifth flue gas is settled. According to the incineration treatment system for waste liquid and waste gas containing phosphate, smoke generated when waste gas and waste liquid are treated in an incineration mode can be subjected to staged sedimentation, and therefore the problems that the incineration treatment efficiency is low, and the resource recovery rate and utilization rate are low are solved.

Description

Technical Field

[0001] The present application relates to the field of waste gas and waste liquid treatment, and in particular to a phosphate-containing waste liquid and waste gas incineration treatment system. Background Art

[0002] BDO (1,4-butanediol) and ethylene glycol are important organic chemical and fine chemical raw materials, and are widely used in many fields. BDO devices and ethylene glycol devices will produce a large amount of waste gas and waste liquid when in use. In addition to organic waste liquid, there will also be waste liquid containing two inorganic salts, disodium hydrogen phosphate and sodium dihydrogen phosphate. Through physical property analysis, disodium hydrogen phosphate and sodium dihydrogen phosphate will decompose into sodium peroxide and phosphorus oxide (phosphorus pentoxide) under high-temperature incineration. Sodium peroxide and carbon dioxide and water in flue gas will generate sodium carbonate, and sodium peroxide and water vapor in flue gas will also generate sodium hydroxide.

[0003] In the prior art, waste gas and waste liquid generated by BDO devices and ethylene glycol devices during use are usually treated by distillation or incineration. The distillation treatment method has high requirements for process control, low treatment efficiency and high cost. The incineration treatment method, due to the high content of salts such as sodium carbonate, sodium peroxide, sodium hydroxide and gaseous phosphorus oxide generated after combustion, is prone to corrosion of the incinerator and slagging and clogging of the incineration system, requiring frequent shutdown for inspection and cleaning, and even production accidents, thereby affecting the incineration efficiency and operational safety of the incineration system. Summary of the invention

[0004] In response to the above problems, the present application provides a phosphate-containing waste liquid and waste gas incineration treatment system, which can carry out phased sedimentation of the flue gas generated when the waste gas and waste liquid are treated by incineration, thereby solving the problems of low incineration treatment efficiency and low resource recovery rate and utilization rate.

[0005] To achieve the purpose of this application, this application provides the following technical solutions:

[0006] The present application provides a phosphate-containing waste liquid and waste gas incineration treatment system, including: an incinerator, a cooling and settling furnace, and a denitrification and settling furnace;

[0007] The incinerator output end of the incinerator is connected to the cooling and settling furnace input end of the cooling and settling furnace, and is used to incinerate waste liquid and waste gas to obtain a first flue gas, and the second flue gas obtained after the first flue gas is subjected to a first heat exchange is passed into the cooling and settling furnace;

[0008] The cooling and settling furnace output end of the cooling and settling furnace is connected to the denitration and settling furnace input end of the denitration and settling furnace, and is used to perform a second heat exchange on the second flue gas to obtain a third flue gas, and to perform a third heat exchange on the third flue gas to obtain a fourth flue gas, and then to pass the fourth flue gas into the denitration and settling furnace after the fourth flue gas is obtained.

[0009] The denitration settling furnace is used to perform denitration treatment on the fourth flue gas to obtain the fifth flue gas, and to settling the sixth flue gas obtained by performing the fourth heat exchange on the fifth flue gas.

[0010] In a possible implementation, the phosphate-containing waste liquid and waste gas incineration treatment system further includes: a dust removal and emission module;

[0011] The dust removal and emission module includes: a bag dust collector and a chimney;

[0012] The bag filter input end is connected to the denitration settling furnace output end of the denitration settling furnace, and is used to remove dust from the sixth flue gas to obtain the seventh flue gas;

[0013] The input end of the chimney is connected to the output end of the bag filter for discharging the seventh flue gas.

[0014] In a possible implementation, the incinerator has a first heat exchange component at the top and an incineration chamber at the bottom; the incineration chamber has a first discharge port at the bottom, and a waste liquid burner and a waste gas burner on the bottom side wall.

[0015] In a possible implementation, the upper part of the cooling and settling furnace is a flue gas passage, and the lower part is a settling chamber;

[0016] A second heat exchange component and a third heat exchange component are arranged in the flue gas passage.

[0017] In a possible implementation, a baffle is provided on the top of the settling chamber; the baffle extends into the interior of the settling chamber, and the bottom of the baffle is lower than the bottom of the output end of the cooling and settling furnace.

[0018] In a possible implementation, the output end of the cooling and settling furnace further has a fourth heat exchange component for exchanging heat with the fourth flue gas.

[0019] In a possible implementation, the denitration settling furnace has a denitration component inside;

[0020] The denitration component includes: a denitration agent spraying component and a partition; the denitration agent spraying component is used to spray the denitration agent into the interior of the denitration settling furnace, and the partition can be opened and closed, and when closed, the interior of the denitration settling furnace is divided into multiple spaces.

[0021] In a possible implementation, the bottom passage of the denitration settling furnace has a fifth heat exchange component.

[0022] In a possible implementation, a first soot blowing component is provided in the flue gas passage of the cooling and settling furnace, for blowing away solid particles on the surfaces of the second heat exchange component and the third heat exchange component;

[0023] The partition of the denitration settling furnace is provided with a second soot blowing assembly for blowing away solid particles on the surface of the partition;

[0024] A third soot blowing component is provided in the bottom passage of the denitration settling furnace for blowing away solid particles on the surface of the fifth heat exchange component.

[0025] In a possible implementation, a condenser is provided at the bottom of the incinerator for cooling the molten salt flowing out from the lower end of the incinerator.

[0026] Beneficial effects:

[0027] The phosphate-containing waste liquid and waste gas incineration treatment system provided by the present application can perform sedimentation treatment on the flue gas generated by incineration in stages, and separate and recover substances such as sodium carbonate, sodium peroxide, sodium hydroxide and gaseous phosphorus oxide in the flue gas in stages, thereby achieving efficient and continuous incineration treatment of waste gas and waste liquid generated by the BDO device and the ethylene glycol device during use, avoiding slagging blockage and corrosion problems caused by incineration, and recovering substances such as sodium carbonate, sodium peroxide, sodium hydroxide and gaseous phosphorus oxide in the waste liquid and waste gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the present application and form a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation to the present application.

[0029] Figure 1 A schematic diagram of the structure of a phosphate-containing waste liquid and waste gas incineration treatment system provided in an embodiment of the present application;

[0030] Figure 2 A schematic diagram of the structure of an incinerator of a phosphate-containing waste liquid and waste gas incineration treatment system provided in an embodiment of the present application;

[0031] Figure 3 A schematic diagram of the structure of a waste liquid burner of a phosphate-containing waste liquid and waste gas incineration treatment system provided in an embodiment of the present application;

[0032] Figure 4 A schematic diagram of the structure of a cooling and settling furnace of a phosphate-containing waste liquid and waste gas incineration treatment system provided in an embodiment of the present application;

[0033] Figure 5 A schematic diagram of the structure of a denitration settling furnace in a phosphate-containing waste liquid and waste gas incineration treatment system provided in an embodiment of the present application;

[0034] Figure 6 A schematic diagram of the structure of the fourth heat exchange pipe of a phosphate-containing waste liquid and waste gas incineration treatment system provided in an embodiment of the present application;

[0035] Figure 7 A schematic diagram of the structure of a dust removal and emission module of a phosphate-containing waste liquid and waste gas incineration treatment system provided in an embodiment of the present application;

[0036] Figure 8 A schematic structural diagram of a steam circulation system for a phosphate-containing waste liquid and waste gas incineration treatment system provided in an embodiment of the present application.

[0037] Reference numerals:

[0038] 100 - incinerator, 110 - incineration chamber, 120 - first heat exchange component, 130 - waste liquid burner, 140 - waste gas burner, 150 - first discharge port, 160 - condenser, 170 - output end of incinerator;

[0039] 200-cooling and settling furnace, 210-cooling and settling furnace input end, 220-second heat exchange component, 230-third heat exchange component, 240-settling chamber, 241-baffle, 242-standby air input end, 250-fourth heat exchange component, 260-cooling and settling furnace output end, 270-second discharge port, 280-first soot blowing component;

[0040] 300-denitrification settling furnace, 310-denitrification settling furnace input end, 320-denitrification agent spraying assembly, 330-partition plate, 340-fifth heat exchange assembly, 350-denitrification settling furnace output end, 360-third discharge port, 370-second soot blowing assembly, 380-third soot blowing assembly;

[0041] 400-Bag dust collector;

[0042] 500-chimney, 510-induced draft fan;

[0043] 600-Stand. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of this application, unless otherwise specified, "plurality" means two or more.

[0046] Example 1

[0047] Figure 1-8 A phosphate-containing waste liquid and waste gas incineration treatment system provided in an embodiment of the present application includes: an incinerator 100, a cooling and settling furnace 200, and a denitrification and settling furnace 300;

[0048] The incinerator output end 170 of the incinerator 100 is connected to the cooling and settling furnace input end 210 of the cooling and settling furnace 200, and is used to incinerate waste liquid and waste gas to obtain a first flue gas, and the second flue gas obtained after the first flue gas is subjected to a first heat exchange is passed into the cooling and settling furnace 200;

[0049] The cooling and settling furnace output end 260 of the cooling and settling furnace 200 is connected to the denitration and settling furnace input end 310 of the denitration and settling furnace 300, so as to perform a second heat exchange on the second flue gas to obtain a third flue gas, and the fourth flue gas obtained after the third heat exchange on the third flue gas is settling and then passed into the denitration and settling furnace 300;

[0050] The denitration settling furnace 300 is used to perform denitration treatment on the fourth flue gas to obtain the fifth flue gas, and to settling the sixth flue gas obtained by performing the fourth heat exchange on the fifth flue gas.

[0051] In a possible implementation, the phosphate-containing waste liquid and waste gas incineration treatment system further includes: a dust removal and emission module;

[0052] The dust removal and emission module includes: a bag filter 400 and a chimney 500;

[0053] The bag filter input end is connected to the denitration settling furnace output end 350 of the denitration settling furnace 300, and is used to remove dust from the sixth flue gas to obtain the seventh flue gas;

[0054] The input end of the chimney 500 is connected to the output end of the bag filter 400 for discharging the seventh flue gas.

[0055] Optionally, the bottom of the chimney 500 is provided with an induced draft fan 510 for discharging the seventh flue gas through the chimney.

[0056] In a possible implementation, the incinerator 100 has a first heat exchange assembly 120 at the top and an incineration chamber 110 at the bottom; the incineration chamber 110 has a first discharge port 150 at the bottom, and a waste liquid burner 130 and a waste gas burner 140 on the bottom side wall.

[0057] Optionally, the bottom of the incineration chamber 110 has a waste liquid burner 130 and a waste gas burner 140; the waste gas burner 140 is used to spray the waste gas generated by the BDO device and the ethylene glycol device when in use into the combustion chamber for incineration; the waste liquid burner 130 is used to spray the waste liquid generated by the BDO device and the ethylene glycol device when in use into the combustion chamber in the form of aerosol for incineration.

[0058] The waste liquid burner 130 has an atomizing steam channel and a waste liquid channel, which are used to atomize and spray the waste liquid through the atomizing steam.

[0059] Optionally, the incinerator 100 has a backup air inlet.

[0060] Optionally, the incinerator 100 is of a vertical side-burning type.

[0061] In a possible implementation, the upper portion of the cooling and settling furnace 200 is a flue gas passage, and the lower portion is a settling chamber 240;

[0062] A second heat exchange component 220 and a third heat exchange component 230 are disposed in the flue gas passage.

[0063] Optionally, the second heat exchange component 220 is used to perform heat exchange and cooling on the second flue gas, and the third heat exchange component 230 is used to control the temperature of the third flue gas to maintain it within a preset range.

[0064] In a possible implementation, the top of the settling chamber 240 has a baffle 241 ; the baffle 241 extends into the settling chamber 240 , and the bottom of the baffle 241 is lower than the bottom of the output end 260 of the cooling and settling furnace.

[0065] The baffle 241 enables the fourth flue gas to sink into the settling chamber, and in the process of raising the output cooling settling furnace 200 , as many solid particles in the fourth flue gas as possible are settled into the settling chamber 240 .

[0066] In a possible implementation manner, the cooling and settling furnace output end 260 further has a fourth heat exchange component 250 for performing heat exchange on the fourth flue gas.

[0067] The fourth heat exchange component 250 is used to control the temperature of the fourth flue gas within a preset range, thereby ensuring efficient denitration reaction between the fourth flue gas and the denitrification agent.

[0068] In a possible implementation, the denitration settling furnace 300 has a denitration component inside;

[0069] The denitration component includes: a denitration agent spraying component 320 and a partition 330; the denitration agent spraying component 320 is used to spray the denitration agent into the interior of the denitration settling furnace 300, and the partition 330 can be opened and closed, and when closed, the interior of the denitration settling furnace is divided into multiple spaces.

[0070] Optionally, there are three partitions 330 , which divide the interior of the denitration settling furnace 300 into four spaces, so that the fourth flue gas can fully react with the denitration agent.

[0071] In a possible implementation, the bottom passage of the denitration settling furnace 300 has a fifth heat exchange component 340 for cooling the fifth flue gas after the denitration reaction to settle the solid particles.

[0072] In a possible implementation, a first soot blowing component 280 is provided in the flue gas passage of the cooling and settling furnace 200, for blowing away solid particles on the surfaces of the second heat exchange component 220 and the third heat exchange component 230;

[0073] The partition 330 of the denitration settling furnace 300 is provided with a second soot blowing assembly 370 for blowing away solid particles on the surface of the partition 330;

[0074] A third soot blowing assembly 380 is provided in the bottom passage of the denitration settling furnace 300 for blowing away solid particles on the surface of the fifth heat exchange assembly 340 .

[0075] The soot blowing assembly is used to sweep away the solid particles attached to the surface of the heat exchange assembly, thereby preventing agglomeration and blockage while reducing the corrosion of the surface of the heat exchange assembly by the solid particles.

[0076] In a possible implementation manner, a condenser 160 is provided at the bottom of the incinerator 100 for cooling the molten salt flowing out from the lower end of the incinerator 100 .

[0077] In a possible implementation, the phosphate-containing waste liquid and waste gas incineration treatment system further includes: a bracket 600 ; the incinerator 100 , the cooling and settling furnace 200 , and the denitration and settling furnace 300 are integrated on the bracket 600 .

[0078] In a possible implementation, an input end of the waste liquid burner 130 is communicated with a waste liquid conveying system, and an input end of the waste gas burner 140 is communicated with a waste gas conveying system.

[0079] Among them, the waste liquid transportation system is mainly composed of waste liquid storage tanks, waste liquid pipes, safety valves, shut-off valves, flow meters, waste liquid pumps, pressure transmitters, flow regulating valves, atomizing steam pipelines, etc. The waste liquid storage tank is equipped with waste liquid inlet, waste liquid outlet, exhaust port, manhole and instrument port, etc. The safety valve of the waste liquid storage system is mainly used for: when the pressure in the waste liquid storage tank exceeds the set value, it automatically opens the exhaust pressure relief to ensure the safety of the storage tank; the atomizing steam pipeline is mainly used for waste liquid atomization to ensure that the waste liquid is completely burned in the furnace; the waste liquid storage tank is a vertical structure, equipped with inlet and outlet, exhaust port, instrument port, manhole, and liquid level meter;

[0080] The exhaust gas delivery system is mainly composed of exhaust gas pipelines, pressure transmitters, flow meters, cut-off valves, flow control valves, etc.

[0081] The waste gas is sent from the incineration device to the incineration boundary area and then to the incinerator for incineration. The pressure and flow of the waste gas pipeline can be recorded in real time through pressure transmitters, flow meters, etc. The waste gas flow can be automatically adjusted through the flow regulating valve according to the actual working conditions; the waste gas buffer tank is a vertical structure with inlet and outlet, sewage outlet, instrument outlet, and safety valve.

[0082] In a possible implementation, the phosphate-containing waste liquid and waste gas incineration treatment system further includes: a conveying system and a heat exchange module;

[0083] The heat exchange module comprises: a first heat exchange component, a second heat exchange component, a third heat exchange component, and a fifth heat exchange component;

[0084] The first heat exchange component is arranged at the upper part of the incinerator, the second heat exchange component is arranged in the flue at the upper part of the cooling and settling furnace, and the fifth heat exchange component is arranged in the flue at the lower part of the denitration and settling furnace;

[0085] The delivery system comprises: a water supply module and an air bag;

[0086] The output end of the water supply module is communicated with the input end of the fifth heat exchange component, and the output end of the fifth heat exchange component is communicated with the input end of the air bag;

[0087] The output end of the lower part of the air bag is connected to the input end of the first heat exchange component, and the output end of the first heat exchange component is connected to the input end of the upper part of the air bag;

[0088] The output end of the lower part of the air bag is also connected to the input end of the second heat exchange component, and the output end of the second heat exchange component is also connected to the input end of the upper part of the air bag;

[0089] The third heat exchange component is arranged in the flue at the upper part of the cooling and settling furnace and is located below the second heat exchange component; the upper output end of the air bag is connected with the input end of the third heat exchange component, and the output end of the third heat exchange component is connected with the lower input end of the air bag;

[0090] The fourth heat exchange component is arranged at the output end of the cooling and settling furnace; the upper output end of the air bag is connected to the input end of the fourth heat exchange component, and the output end of the fourth heat exchange component is connected to the output end of the first heat exchange component.

[0091] Example 2

[0092] On the basis of the above-mentioned embodiments, the present application provides a method for incinerating phosphate-containing waste liquid and waste gas, including the following steps S101 to S105:

[0093] Step S101, after the incinerator is heated to a preset temperature, phosphate-containing waste liquid and waste gas are added through a burner arranged at the bottom of the incinerator, and the phosphate-containing waste liquid and waste gas are fully burned in the incinerator to generate initial flue gas.

[0094] In the embodiment of the present application, after the temperature of the incineration chamber of the incinerator is heated to the incineration temperature, the phosphate-containing waste liquid is transported from the waste liquid storage tank to the waste liquid burner by a waste liquid pump, so that the waste liquid is atomized by steam in the waste liquid burner, and then sprayed into the incineration chamber of the incinerator through the waste liquid burner arranged at the bottom of the incinerator for incineration and pyrolysis, generating flue gas and high-temperature molten ammonium carbonate, sodium peroxide, sodium hydroxide and gaseous phosphorus oxide, wherein the waste liquid storage tank contains a mixed waste liquid containing multiple components. Here, the incineration chamber temperature corresponds to the preset temperature in the present application. As a feasible implementation method, the preset temperature can be 1100°C, the maximum operating temperature of the incinerator can be 1500°C, and the outer wall temperature of the furnace body is not higher than 60°C. In the embodiment of the present application, after the waste gases from the outside of the incineration device are evenly mixed in the waste gas buffer tank, they enter the incineration chamber through the waste gas and auxiliary fuel burner for incineration and pyrolysis.

[0095] In the embodiment of the present application, the initial flue gas generated by the incineration chamber is a mixture of the flue gas after the incineration of the waste liquid and the flue gas generated after the incineration of the waste gas, which includes at least molten sodium carbonate, sodium peroxide and sodium hydroxide. The initial flue gas flow rate is relatively low. The molten sodium carbonate, sodium peroxide and sodium hydroxide settle and flow downward under the action of gravity. After flowing out in a molten state from the bottom of the incineration chamber, they are cooled into a solid state by the desalted water and precipitated based on the surface of the water cooler located at the bottom of the incineration chamber.

[0096] In an embodiment of the present application, the waste liquid storage tank is a vertical structure, in which a waste liquid inlet, a waste liquid outlet, an exhaust port, an agitator, a pressure port, a sewage outlet and a liquid level gauge are arranged, and the exhaust port is used to automatically open the exhaust pressure relief when the pressure in the waste liquid storage tank is detected to exceed the preset threshold value, so as to ensure the safety of the storage tank. In an embodiment of the present application, the waste liquid storage tank and the waste liquid delivery system connected to the waste liquid pump and the waste liquid burner take sealing measures to avoid leakage of waste liquid. Among them, the capacity of the waste liquid storage tank must meet the operating consumption of the incineration device for at least 15 days, that is, it must reach at least 200m3. It should be noted that the incineration device refers to the incineration treatment system used in the phosphate-containing waste liquid and waste gas incineration treatment method of the embodiment of the present application, including the post-processing process after the incinerator.

[0097] In the embodiment of the present application, the exhaust gas buffer tank is a vertical structure, in which an air inlet, an air outlet, a pressure port, a safety valve, and a sewage outlet are provided.

[0098] In the embodiment of the present application, the incinerator adopts vertical bottom burning, and a plurality of burners are arranged circumferentially at the bottom of the incinerator. The burners include at least a waste liquid burner and a waste gas burner. In order to ensure the atomization quality of the waste liquid and steam after efficient mixing, the waste liquid burner can adopt superheated steam-assisted atomization based on an internal mixing steam atomizing nozzle. The waste liquid of the internal mixing steam atomizing nozzle is sprayed into the mixing chamber from the middle annular hole of the nozzle, and collides and mixes with the steam sprayed from the corresponding small hole on the side of the nozzle to perform the first atomization; then, after the pressure inside the mixing chamber is established, the gas-liquid mixture after the first atomization is sprayed from the annular spray hole of the mixing chamber to the incinerator for combustion in the incinerator. Here, in order to obtain a smaller and uniform distribution of the diameter of the atomized droplets, it is necessary to reasonably adjust the parameters such as the pore diameter, the liquid pore diameter, the gas-liquid momentum ratio, and the length of the mixing chamber. Considering that the waste liquid not only participates in the combustion reaction, but also absorbs a large amount of heat, in order to reduce the influence of the waste liquid spray on the burner flame, it is necessary to control the spray angle and the jet velocity to achieve a better match with the furnace.

[0099] In the embodiment of the present application, the exhaust gas burner adopts a swirl form to increase the contact area between the exhaust gas and the combustion-supporting air to make the combustion more complete.

[0100] In a possible implementation manner, 8 burners are arranged circumferentially at the bottom of the incinerator of this embodiment, of which 4 waste liquid burners are arranged opposite to each other in pairs on both sides of the bottom of the incinerator; 4 exhaust gas + auxiliary fuel burners (corresponding to the exhaust gas burners in the embodiment of the present application) are arranged opposite to each other in pairs on both end surfaces of the bottom of the incinerator; the exhaust gas + auxiliary fuel burners are combined burners, which can burn auxiliary fuel gas or exhaust gas alone, or burn exhaust gas and auxiliary fuel gas at the same time; the exhaust gas + auxiliary fuel burners can be used for baking the furnace and heating; all exhaust gas + auxiliary fuel burners are provided with a ever-burning lamp and a ever-burning lamp combined ignition rod. When one of the exhaust gas + auxiliary fuel burners is an ignition burner, 3 flame monitors are configured, and the other exhaust gas + auxiliary fuel burners are each configured with a flame detector. The entire system is configured with an automatic igniter to realize the PLC automatic ignition function.

[0101] Step S102: Cooling the initial flue gas flowing into the top of the incinerator based on the first heat exchange component to obtain the first flue gas.

[0102] In an embodiment of the present application, after the flue gas at a preset temperature flows out from the incineration chamber of the incinerator, the initial flue gas is cooled by heat exchange through the first heat exchange component located at the top of the incinerator, and the flue gas that has undergone heat exchange and cooling flows out through the outlet of the first heat exchange component to obtain the first flue gas. Among them, the molten sodium peroxide and sodium hydroxide in the initial flue gas continue to be separated, and the solid sodium carbonate after cooling will settle into the incineration chamber of the incinerator, and then melt and be discharged from the bottom of the incineration chamber. Here, it should be noted that the molten slag discharged from the bottom of the incinerator in steps S101 to S102 is most of the residue in the waste liquid and waste gas treatment process (excluding phosphorus oxide). In an embodiment of the present application, after the above-mentioned molten slag flows out from the bottom of the incinerator, the molten slag (corresponding to the molten salt particles in the embodiment of the present application) is cooled based on a water cooler to obtain solid salt particles.

[0103] In an embodiment of the present application, step S102 specifically includes: performing heat exchange with the initial flue gas based on the heat-absorbing coating on the surface of the riser and the downcomer of the first heat exchange component, so as to transfer the first heat of the initial flue gas to the inner walls of the riser and the downcomer to obtain the first flue gas; wherein the riser and the downcomer are vertical water pipe-type structures uniformly arranged inside the first heat exchange component; the heat-absorbing coating can be selected from metal oxides such as iron oxide, metal nitrides, ceramic materials or composite materials.

[0104] In the embodiment of the present application, the temperature of the second flue gas at the outlet of the first heat exchange component is 600°C±10°C.

[0105] Step S103: exchanging heat with the second flue gas in a second heat exchange component to obtain a cooled third flue gas, and exchanging heat with the third flue gas in a third heat exchange component to obtain a cooled fourth flue gas.

[0106] In an embodiment of the present application, the second flue gas coming out of the first heat exchange component contains gaseous phosphorus oxide, a small amount of solid sodium carbonate particles, a small amount of molten sodium peroxide and sodium hydroxide droplets. The second flue gas flows through the second heat exchange component and the third heat exchange component to obtain a fourth flue gas after heat exchange and cooling, in which a small amount of molten sodium peroxide and sodium hydroxide droplets solidify, and the gaseous phosphorus oxide becomes liquid and then becomes solid.

[0107] In the embodiment of the present application, the flue gas temperature at the outlet of the second heat exchange component is 380±10°C; the flue gas temperature at the outlet of the third heat exchange component is 320°C±10°C.

[0108] Step S104: after the fourth flue gas enters the settling furnace, the flow direction of the fourth flue gas is changed in the settling furnace to perform solid-gas separation on the fourth flue gas, wherein the solid particles are discharged from the bottom of the settling furnace.

[0109] In the embodiment of the present application, the fourth flue gas exiting the third heat exchange component contains a small amount of sodium carbonate particles, a small amount of sodium peroxide particles, a small amount of sodium hydroxide particles and phosphorus oxide particles. After the fourth flue gas is transported to the settling furnace, it flows downward, turns upward and then horizontally in the settling furnace. During this period, the solid particles (corresponding to the solid particles in the embodiment of the present application) settle at the bottom of the settling furnace and are discharged from the bottom of the settling furnace.

[0110] In the embodiment of the present application, the settling furnace is an air distribution settling chamber, which is used to collect gas-solid particulate matter generated in the convection evaporator and particulate matter such as P2O5 and sodium salt that are cooled and solidified by the air distribution. As a feasible implementation method, the air distribution settling chamber of the embodiment of the present application includes a conical shell, an air inlet, and a slag discharge port at the bottom of the settling furnace. When the fourth flue gas passes through the air distribution settling chamber, cold air is introduced through the air inlet, so that P2O5, sodium salt and other substances in the fourth flue gas are cooled and solidified and discharged from the slag discharge port.

[0111] Step S105: After cooling the fourth flue gas to a target temperature based on the fourth heat exchange component, denitrification treatment is performed on the fourth flue gas at the target temperature.

[0112] In the embodiment of the present application, the fourth flue gas exiting the settling furnace passes through the fourth heat exchange component horizontally to achieve further cooling.

[0113] In the embodiment of the present application, the fourth heat exchange assembly is mainly composed of a shell, a heat exchange tube, a steam inlet, a steam outlet, etc. When the flue gas passes through the steam superheater heat exchange tube, the saturated steam in the heat exchange tube is heated to heat the saturated steam into superheated steam. In the embodiment of the present application, the preset temperature is 300℃±10℃.

[0114] In the embodiment of the present application, after the fourth flue gas reaches the target temperature, the fourth flue gas contains a very small amount of sodium carbonate particles, a very small amount of sodium peroxide particles, a very small amount of sodium hydroxide particles and a small amount of phosphorus oxide particles, and the fourth flue gas is subjected to denitration treatment in the denitration section. In the embodiment of the present application, after the fourth flue gas comes out of the fourth heat exchange component, it enters the vertical flue gas denitration section downward, and is fully mixed with the flue gas containing the denitration agent uniformly sprayed from the top of the flue gas denitration section at the top of the flue gas denitration section, and passes through two catalyst beds in sequence downward, and is completely denitrated, reducing the nitrogen oxide content in the flue gas to 50mg / m 3 For example, the denitrification agent may be ammonia generated by thermal decomposition of urea.

[0115] In the embodiment of the present application, the denitrification section adopts a selective catalytic reduction (SCR) denitrification hybrid process for denitrification, which includes a control and monitoring system, a urea solution storage system, a transportation system, a denitrification reactor and ancillary systems. Here, the control and monitoring system, the urea solution storage system, and the transportation system can refer to the existing design and will not be described in detail. In the embodiment of the present application, the denitrification reactor (corresponding to the denitrification settling furnace 300 in the embodiment of the present application) in the SCR denitrification hybrid process has a denitrification component inside, and the denitrification component includes: a denitrification agent spraying component 320 and a partition 330; the denitrification agent spraying component 320 is used to spray the denitrification agent into the denitrification settling furnace 300, and the partition 330 can be opened and closed, and when closed, the denitrification settling furnace is divided into multiple spaces; optionally, the partition 330 is three, and the denitrification settling furnace 300 is divided into four spaces, which can make the third flue gas fully react with the denitrification agent; as a feasible implementation method, the denitrification settling The bottom passage of the furnace 300 is provided with a heat exchange component 340, which is used to cool the third flue gas after the denitrification reaction to settle the solid particles; the flue gas passage of the cooling and settling furnace 200 is provided with a first soot blowing component 280, which is used to purge the solid particles on the surface of the second heat exchange component 220 and the third heat exchange component 230; the partition 330 of the denitrification settling furnace 300 is provided with a second soot blowing component 370, which is used to purge the solid particles on the surface of the partition 330; the bottom passage of the denitrification settling furnace 300 is provided with a third soot blowing component 380, which is used to purge the solid particles on the surface of the fifth heat exchange component 340.

[0116] In the embodiment of the present application, the hydrolysis flue gas pyrolysis method is adopted, that is, urea is first dissolved in a urea dissolving tank with warm water greater than 38°C, and then sprayed into the front flue of the denitration reactor through a metering and conveying system. Since the flue gas temperature at the inlet of the denitration reactor is mostly greater than 200°C, spraying urea at this temperature can prepare most of the urea into ammonia, and can save investment.

[0117] In the embodiment of the present application, the flue gas denitrification section is provided with a steam soot blower (corresponding to the soot blowing assembly of the embodiment of the present application (including the first soot blowing assembly 280, the second soot blowing assembly 370 and the third soot blowing assembly 380)), which removes dust and salt accumulated on the surface of the denitrification agent from time to time to maintain the reaction activity of the catalyst.

[0118] In an embodiment of the present application, in step S105, the fourth flue gas at the target temperature is subjected to a denitration treatment, including: mixing the fourth flue gas at the target temperature with a denitrifying agent to obtain a denitrified mixed flue gas, and allowing the denitrified mixed flue gas to sequentially pass through a first catalyst bed and a second catalyst bed provided in a denitrification section to obtain a fifth flue gas; wherein the denitrifying agent is uniformly sprayed into the denitrification section from the top of the denitrification section, and is sprayed into the denitrification section simultaneously with the third flue gas; illustratively, the denitrifying agent is aqueous ammonia.

[0119] As a feasible implementation mode, when the denitrification mixed flue gas has not passed through the second catalyst bed, the dust and salt on the surface of the first denitrification catalyst of the second catalyst bed are cleared based on a first preset time interval to maintain the activity of the first denitrification catalyst; when the denitrification mixed flue gas has not passed through the first catalyst bed, the dust and salt on the surface of the second denitrification catalyst of the first catalyst bed are cleared based on a second preset time interval to maintain the activity of the second denitrification catalyst.

[0120] In the embodiment of the present application, in view of the fact that the fifth flue gas after denitration in the flue gas denitration stage may still contain a very small amount of sodium carbonate particles, a very small amount of sodium peroxide particles, a very small amount of sodium hydroxide particles and a small amount of phosphorus oxide particles, in order to remove the above particles, a deoxygenated water preheater and a desalted water preheater (corresponding to the fifth heat exchange component in the embodiment of the present application) are provided after the flue gas denitration stage, so that the fifth flue gas after denitration passes downward through the deoxygenated water preheater and the desalted water preheater in turn to be further cooled to 140°C ± 10°C, thereby the solid particles are further discharged from the lowest point of the flue at the bottom of the desalted water preheater, wherein the desalted water comes from outside the boundary area, and is deoxygenated by the deaerator after preheating, and the deoxygenated water comes from the deaerator through the deoxygenated water pump, and enters the air bag after overheating. It should be noted that the air used in the embodiment of the present application is forced to be supplied by a blower.

[0121] The incineration treatment method for phosphate-containing waste liquid and waste gas of the embodiment of the present application is for incineration flue gas in different temperature ranges. By performing heat exchange and sedimentation treatment on the flue gas in stages, substances such as sodium carbonate, sodium peroxide, sodium hydroxide and gaseous phosphorus oxide in the flue gas are separated and recovered in stages, thereby achieving simple, efficient and continuous incineration treatment of waste gas and waste liquid generated by the BDO device and the ethylene glycol device during use, avoiding slagging blockage and corrosion problems caused by incineration, and efficiently recovering substances such as sodium carbonate, sodium peroxide, sodium hydroxide and gaseous phosphorus oxide in the waste liquid and waste gas.

[0122] Example 3

[0123] Based on the above-mentioned embodiment, this embodiment performs the following test calculations on the incineration results:

[0124] The process parameters of waste liquid and waste gas in this embodiment are as follows:

[0125] (1) Salt-containing wastewater

[0126] Total mass flow: 380kg / h;

[0127]

[0128]

[0129] (2) Wastewater

[0130] Total mass flow rate: 220.83kg / h;

[0131]

[0132] (3) Waste gas

[0133] Total mass flow rate: 610kg / h;

[0134]

[0135]

[0136] (4) Auxiliary fuel

[0137] Fuel Name natural gas Calorific value <![CDATA[8400kcal / Nm 3 ]]>

[0138] By calculation, the co-firing is 20Nm 3 / h fuel gas, with 26067.8Nm 3 / h cold air can maintain the combustion temperature of 1100℃ stable operation. The cold air is added to the combustion air from the burner. At this time, the heat load is 10.7MW and the smoke volume out of the combustion chamber is 27856.7Nm 3 / h, where (mol%):

[0139] O2:11.64%, N2:74.61%, CO2:5.86%, H2O:7.89%,

[0140] P2O5: 9.0kg / h Na2CO3 (containing a small amount of Na2O2 and NaOH): 8.5kg / h, it is estimated that 70% (12.3kg / h) is discharged in molten state from the bottom of the incineration chamber, 25% (4.4kg / h) is discharged intermittently in solid form from the sedimentation chamber and the bottom of the denitrification section, and 5% (0.9kg / h) is discharged from the bottom of the bag dust collector.

[0141] The excess air coefficient is 2.4, which is very reliable incineration data.

[0142] Dry basis oxygen content (mol%): 12.64%, slightly greater than the requirement of 9% to 11% on dry basis oxygen content in GB18484-2020.

[0143] The external output is 15170kg / h of 1.3MPa saturated steam.

[0144] in:

[0145] The flue gas volume out of the first heat exchange component at the top of the incinerator is 33043.3Nm 3 / h, where (mol%):

[0146] O2:13.11%, N2:75.30%, CO2:4.94%, H2O:6.65%,

[0147] The flue gas volume out of the settling chamber is 39665Nm 3 / h, where (mol%):

[0148] O2:14.43%, N2:75.92%, CO2:4.11%, H2O:5.54%,

[0149] Emission of three wastes: This device emits flue gas and solid waste.

[0150] Under ideal conditions, smoke emissions: 29856.7Nm 3 / h, exhaust gas temperature 143℃.

[0151] Flue gas components (mol%):

[0152] O2:11.64%, N2:74.61%, CO2:5.86%, H2O:7.89%,

[0153] NO X :≤50mg / m 3

[0154] Dust content: ≤10mg / m 3, mainly phosphorus oxide and sodium carbonate (containing a small amount of sodium peroxide and sodium hydroxide).

[0155] In the embodiment of the present application, the waste liquid and waste gas enter the burner through the storage and transportation system and are fully incinerated in the incineration chamber to generate hot flue gas at about 1100°C. The flue gas passes through the first heat exchange component at the upper part of the incineration chamber, and the temperature drops to 600°C. Then, it enters the convection evaporator I, and the temperature drops to 380°C. Then, it enters the convection evaporator and is cooled to 320°C. Then, it enters the sedimentation section to settle the solid particles in the flue gas. After the temperature drops to 300°C through the steam superheater, it enters the SCR denitration section for denitration, and the nitrogen oxide content in the flue gas is reduced to 50mg / m 3 After denitration, the flue gas passes through the deoxygenated water preheater and the desalted water preheater to recover the residual heat and preheat the desalted water and deoxygenated water. After the flue gas passes through the desalted water preheater, the temperature drops to 143°C and enters the bag filter to recover solid particles. The particle content drops to 10mg / m 3 , and discharged into the atmosphere through the chimney through the induced draft fan.

[0156] In the several embodiments provided in the present application, it should be understood that the disclosed systems, modules and methods can be implemented in other ways. For example, the module embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, modules or units, which can be electrical, mechanical or other forms.

[0157] The above embodiments are only used to illustrate the technical solution of the present application, but not to limit it. The present application is not limited to the exact structure described above and illustrated in the accompanying drawings, and it cannot be determined that the specific implementation of the present application is limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, various changes and modifications made without departing from the concept of the present application should be deemed to belong to the protection scope of the present application.

Claims

1. A phosphate-containing waste liquid and waste gas incineration treatment system, characterized in that: include: Incinerator (100), cooling and settling furnace (200), denitration and settling furnace (300); The incinerator output end (170) of the incinerator (100) is connected to the cooling and settling furnace input end (210) of the cooling and settling furnace (200), and is used to incinerate waste liquid and waste gas to obtain first flue gas, and the second flue gas obtained after the first flue gas is subjected to a first heat exchange is passed into the cooling and settling furnace (200); The cooling and settling furnace output end (260) of the cooling and settling furnace (200) is connected to the denitration and settling furnace input end (310) of the denitration and settling furnace (300), and is used to perform a second heat exchange on the second flue gas to obtain a third flue gas, and to perform settling on the fourth flue gas obtained after the third heat exchange on the third flue gas, and then pass the fourth flue gas into the denitration and settling furnace (300); The denitration settling furnace (300) is used to perform a denitration treatment on the fourth flue gas to obtain a fifth flue gas, and to settling a sixth flue gas obtained by performing a fourth heat exchange on the fifth flue gas.

2. The phosphate-containing waste liquid and waste gas incineration treatment system according to claim 1, characterized in that: Also included: a dust removal and emission module; The dust removal and emission module comprises: a bag dust collector (400) and a chimney (500); The bag filter input end is connected to the denitration settling furnace output end (350) of the denitration settling furnace (300) and is used to remove dust from the sixth flue gas to obtain a seventh flue gas; The input end of the chimney (500) is connected to the output end of the bag filter (400) for discharging the seventh flue gas.

3. The phosphate-containing waste liquid and waste gas incineration treatment system according to claim 1, characterized in that: The incinerator (100) has a first heat exchange component (120) at the top and an incineration chamber (110) at the bottom; the incineration chamber (110) has a first discharge port (150) at the bottom, and a waste liquid burner (130) and a waste gas burner (140) at the bottom side wall.

4. The phosphate-containing waste liquid and waste gas incineration treatment system according to claim 1, characterized in that: The upper part of the cooling and settling furnace (200) is a flue gas passage, and the lower part is a settling chamber (240); A second heat exchange component (220) and a third heat exchange component (230) are arranged in the flue gas passage.

5. The phosphate-containing waste liquid and waste gas incineration treatment system according to claim 4, characterized in that: The top of the settling chamber (240) is provided with a baffle (241); the baffle (241) extends into the interior of the settling chamber (240), and the bottom of the baffle (241) is lower than the bottom of the output end (260) of the cooling and settling furnace.

6. The phosphate-containing waste liquid and waste gas incineration treatment system according to claim 5, characterized in that: The cooling and settling furnace output end (260) further comprises a fourth heat exchange component (250) for performing heat exchange on the fourth flue gas.

7. The phosphate-containing waste liquid and waste gas incineration treatment system according to claim 1, characterized in that: The denitration settling furnace (300) has a denitration component inside; The denitration component comprises: a denitration agent spraying component (320) and a partition (330); the denitration agent spraying component (320) is used to spray the denitration agent into the interior of the denitration settling furnace (300); the partition (330) can be opened and closed, and when closed, the interior of the denitration settling furnace is divided into a plurality of spaces.

8. The phosphate-containing waste liquid and waste gas incineration treatment system according to claim 4, characterized in that: The bottom passage of the denitration settling furnace (300) has a fifth heat exchange component (340).

9. The phosphate-containing waste liquid and waste gas incineration treatment system according to claim 8, characterized in that: The flue gas passage of the cooling and settling furnace (200) is provided with a first soot blowing component (280) for blowing away solid particles on the surfaces of the second heat exchange component (220) and the third heat exchange component (230); A second soot blowing assembly (370) is provided at the partition (330) of the denitration settling furnace (300) for blowing away solid particles on the surface of the partition (330); A third soot blowing assembly (380) is provided in the bottom passage of the denitration settling furnace (300) for blowing away solid particles on the surface of the fifth heat exchange assembly (340).

10. The phosphate-containing waste liquid and waste gas incineration treatment system according to claim 1, characterized in that: The bottom of the incinerator (100) is provided with a condenser (160) for cooling the molten salt flowing out from the lower end of the incinerator (100).

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