Evaporation tower and evaporation tower arch breaking method

Abstract

The invention relates to the technical field of wastewater treatment devices, in particular to an evaporation tower and an evaporation tower arch breaking method, and the evaporation tower comprises an evaporation tower body and an arch breaking pipe. The arch breaking pipe is used for introducing compressed gas into the evaporation tower body close to the waste residue discharge port, the compressed gas is used for improving the fluidity of solid waste at the waste residue discharge port, a part of pipe body of the arch breaking pipe is located in the evaporation tower body, and smoke in the evaporation tower body heats the arch breaking pipe so that the compressed gas in the arch breaking pipe can be heated; and the heated compressed gas is used for reducing the humidity of the solid waste at the waste residue discharge port. In the evaporation tower provided by the invention, part of the pipe body of the arch breaking pipe is positioned in the evaporation tower body, and the arch breaking pipe is heated by utilizing flue gas in the evaporation tower, so that the temperature of compressed gas in the arch breaking pipe is increased. And when the heated compressed gas is introduced into the waste residue discharge port, the humidity of the solid waste can be reduced, the fluidity of the solid waste is further improved, and the solid waste can be conveniently discharged.

Description

Technical Field

[0001] The present application relates to the technical field of wastewater treatment devices, and in particular to an evaporation tower and an evaporation tower arch breaking method. Background Art

[0002] At present, there is a new type of power plant desulfurization wastewater treatment technology in China, namely the "multi-effect flash concentration + low-temperature flue gas evaporation" technology, which has become increasingly mature and rapidly promoted in the domestic market. In this technology, the desulfurization wastewater is first treated by the multi-effect flash concentration system, and the concentrated waste liquid then enters the high-temperature evaporation tower. Here, the waste liquid is evaporated using the remaining low-temperature flue gas generated by coal combustion. During the evaporation process, the water in the wastewater is discharged with the flue gas in the form of water vapor, and the solid substances such as crystallized salt and ash remaining after evaporation fall to the bottom of the high-temperature evaporation tower. These solid ash slags are transported to the slag silo for temporary storage through the discharge valve at the bottom of the tower and the silo pump system.

[0003] However, during the operation of the system, the solid ash in the high-temperature evaporation tower often has high humidity and poor fluidity, which easily leads to the accumulation of ash at the bottom of the high-temperature evaporation tower, forming the so-called "bridge" phenomenon at the bottom of the tower. This leads to poor ash discharge and large amounts of accumulation in the evaporation tower, which seriously affects the safe and stable operation of the system.

[0004] In order to solve the problem of "bridging" of ash in the cone bucket at the bottom of the evaporation tower, some solutions have been taken, but each has its own shortcomings. For example, the method of installing an air hammer on the silo wall can try to vibrate the ash, but if the ash is humid, it will make the ash accumulate more densely in the silo and more difficult to unload. At the same time, the vibration of the air hammer will produce noise pollution, and long-term use may also cause the silo to deform or crack. In addition, the method of increasing the discharge port or reducing the top angle of the hopper has limited effect on solving the "bridging" phenomenon, especially for materials with high humidity. Another method is to install an air cannon on the silo wall, but the air cannon is large in size, heavy in weight, complicated to install, and extremely noisy when used. In addition, the cold air injected by the air cannon has high humidity, which will quickly cool the ash, resulting in increased humidity and reduced fluidity. Summary of the invention

[0005] The purpose of the present application is to provide an evaporation tower and an evaporation tower arch breaking method, wherein the evaporation tower can reduce the humidity of solid waste, improve the fluidity of solid waste, eliminate "bridging", and promote the discharge of solid waste.

[0006] In order to achieve the above-mentioned objectives, in the first aspect, an embodiment of the present application provides an evaporation tower, comprising an evaporation tower body and a broken arch pipe, the evaporation tower body being provided with a flue gas inlet, a flue gas outlet, a waste liquid inlet and a waste residue outlet; the broken arch pipe being used to introduce compressed gas into the evaporation tower body near the waste residue outlet, the compressed gas being used to improve the fluidity of the solid waste at the waste residue outlet, part of the tube body of the broken arch pipe being located in the evaporation tower body, the flue gas in the evaporation tower body heating the broken arch pipe to heat the compressed gas in the broken arch pipe, and the heated compressed gas being used to reduce the humidity of the solid waste at the waste residue outlet.

[0007] In one embodiment, the tube body on the broken arch tube located inside the evaporation tower body is a heating tube segment, which is spirally coiled inside the evaporation tower body. The heating tube segment is located on the moving path of the flue gas so that the flue gas heats the compressed gas inside the heating tube segment.

[0008] In one embodiment, the evaporation tower body includes an inlet section, a straight section and a conical section, the inlet section, the straight section and the conical section are coaxially fixedly connected, the smoke inlet is arranged at the inlet section, the smoke outlet is arranged at the straight section, and the waste residue discharge outlet is arranged at one end of the conical section away from the straight section; along a first direction, the compressed gas outlet of the arch-breaking pipe is arranged within a range of one quarter to one half of the height of the conical section, the first direction is parallel to the axis of the conical section and points from the conical section to the straight section; the arch-breaking pipe also includes an external pipe section for connecting the compressed gas outlet with the outlet of the heating pipe section, and the compressed gas heated in the heating pipe section is passed into the compressed gas outlet through the external pipe section; the external pipe section is located outside the evaporation tower body, and an air intake valve for opening or closing the external pipe section is provided on the external pipe section.

[0009] In one embodiment, a heat-insulating component is disposed on the outer wall of the external pipe section, and the heat-insulating component reduces the heat loss of the compressed gas in the external pipe section to the outside.

[0010] In one embodiment, along the first direction, the inlet of the heating tube section is arranged within a range of one quarter to one half of the height of the straight tube section.

[0011] In one embodiment, the compressed gas outlet of the arch-breaking pipe is arranged at the conical cylinder section, and the compressed gas outlet includes a first outlet and a second outlet, and the opening direction of the first outlet is arranged along the radial direction of the conical cylinder section; the inner wall of the conical cylinder section is the inner wall of the conical cavity, and the opening direction of the second outlet is arranged along the inner wall of the conical cavity of the conical cylinder section and toward the waste slag discharge outlet.

[0012] In one embodiment, at least two compressed gas outlets are provided on the arch-breaking pipe.

[0013] In a second aspect, an embodiment of the present application further provides an evaporation tower arch breaking method, comprising:

[0014] The waste liquid is sprayed into the evaporation tower body. Flue gas is introduced into the evaporation tower body, and the flue gas heats the waste liquid, so that the water in the waste liquid evaporates into steam, and the steam is discharged from the evaporation tower body along with the flue gas. At the same time, the solid waste remaining after the waste liquid evaporates is discharged from the evaporation tower body.

[0015] Compressed gas is intermittently or continuously introduced into the evaporation tower body through the broken arch pipe to increase the fluidity of the solid waste.

[0016] The arch-breaking pipe is spirally coiled and fixed in the evaporation tower body, and the arch-breaking pipe is heated by flue gas to heat the compressed gas in the arch-breaking pipe. The heated compressed gas can heat the solid waste to reduce the humidity of the solid waste.

[0017] The length of the broken arch pipe in the evaporation tower is L. in:

[0018] d is the diameter of the broken arch pipe (200), in meters.

[0019] Q is the total flue gas flow rate, in kg / h.

[0020] Q1 is the amount of flue gas consumed by evaporating 1 ton of waste liquid concentrate, in kg / h.

[0021] Q0 is the evaporation capacity of wastewater concentrate per unit time, in t / h.

[0022] C1 is the specific heat capacity of flue gas, which is 1.122KJ / (kg.℃) at 300℃.

[0023] K is the total heat transfer coefficient, and the empirical value is set to 800-1000W / m 2 .℃.

[0024] Δt1 is the temperature difference between the flue gas inlet and outlet, in °C.

[0025] Δt2 is the temperature difference between the inlet and outlet of the compressed gas, in °C.

[0026] In one embodiment, the water content of the compressed gas introduced into the evaporation tower body through the broken arch pipe is less than 0.5 g / m 3 .

[0027] In one embodiment, Δt2 ≥ 130° C., and the pressure P of the compressed gas ≥ 0.5 MPa.

[0028] In the evaporation tower provided in the embodiment of the present application, part of the arch-breaking pipe is located in the evaporation tower body, and the arch-breaking pipe is heated by the flue gas in the evaporation tower, so that the compressed gas in the arch-breaking pipe is heated. When the heated compressed gas is passed into the waste residue discharge port, the humidity of the solid waste can be reduced, and the fluidity of the solid waste is further improved, so that it is easy to discharge.

[0029] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A structural schematic diagram of one embodiment of an evaporation tower provided in an embodiment of the present application from one perspective;

[0032] Figure 2 A schematic structural diagram of two perspectives of one embodiment of an evaporation tower provided in an embodiment of the present application.

[0033] icon:

[0034] 100- evaporation tower body; 102- inlet section; 104- straight section; 106- cone section; 110- flue gas inlet; 120- flue gas outlet; 130- waste liquid inlet; 140- waste residue outlet;

[0035] 200-arch-breaking pipe; 210-heating pipe section; 220-external pipe section; 230-first outlet; 240-second outlet;

[0036] 300-air source; 400-warehouse pump; 600-intake valve. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0038] In the description of this application, it should be noted that the terms "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0039] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] The embodiments of the present application provide an evaporation tower and an evaporation tower arch breaking method, and the evaporation tower arch breaking method can be applied to the evaporation tower.

[0041] First, as Figure 1 As shown, an evaporation tower provided in an embodiment of the present application includes an evaporation tower body 100 and a broken arch tube 200 .

[0042] like Figure 1 As shown, the evaporation tower body 100 is provided with a smoke inlet 110 for the smoke to be introduced into the evaporation tower body 100, a smoke outlet 120 for discharging the smoke out of the evaporation tower body 100, a waste liquid inlet 130 for introducing the waste liquid that exchanges heat with the smoke and generates solid waste into the evaporation tower body 100, and a waste residue outlet 140 for discharging the solid waste out of the evaporation tower body 100.

[0043] Exemplarily, the temperature of the flue gas introduced into the flue gas inlet 110 is, for example, 270° C. to 330° C., or above 330° C.

[0044] The flue gas introduced at the flue gas inlet 110 heats the waste liquid. The temperature of the flue gas is higher than that of the waste liquid, so that the water in the waste liquid is decomposed into steam and discharged from the flue gas outlet 120, and the salt in the waste liquid is crystallized into solid and discharged from the waste residue discharge outlet 140. The flue gas that heats the waste liquid will cool down. By way of example, the temperature of the flue gas discharged from the flue gas outlet 120 is, for example, 180°C to 220°C.

[0045] The waste liquid is, for example, desulfurization waste water.

[0046] In the prior art, solid wastes such as solids crystallized from waste liquid and dust gather at the waste residue discharge outlet. Due to operational reasons, part of the waste liquid is not completely evaporated and falls into the crystallized solids and dust at the waste residue discharge outlet, resulting in higher humidity of the solid waste at the waste residue discharge outlet, reduced fluidity, and difficulty in discharging the solid waste.

[0047] Exemplarily, a spray gun is provided at the waste liquid inlet 130 of the evaporation tower body 100, and the spray gun sprays the waste liquid into the evaporation tower body 100; exemplary, a plurality of spray guns are provided, and correspondingly, a plurality of waste liquid inlets 130 are also provided; for example, two spray guns are provided around the circumference of the evaporation tower body 100, and two waste liquid inlets 130 are provided accordingly.

[0048] Exemplarily, the flue gas inlet 110 is connected to a high-temperature flue gas source, such as a boiler.

[0049] In the present application, a broken arch pipe 200 is provided, which is used to introduce compressed gas into the evaporation tower body 100 near the waste residue discharge port 140 . The compressed gas is used to improve the fluidity of the solid waste at the waste residue discharge port 140 , making it easier for the solid waste to be discharged from the waste residue discharge port 140 .

[0050] In addition, part of the arch-breaking pipe 200 is located in the evaporation tower body 100. The flue gas in the evaporation tower body 100 heats the arch-breaking pipe 200 to heat the compressed gas in the arch-breaking pipe 200. The heated compressed gas heats the solid waste at the waste slag discharge port 140, so that the moisture in the solid waste is heated to form steam. The steam is separated from the solid waste, thereby reducing the humidity of the solid waste at the waste slag discharge port 140, further improving the fluidity of the solid waste, and facilitating the discharge of the solid waste.

[0051] Exemplarily, the arch-breaking pipe 200 is connected to a gas source 300 , which provides dry compressed gas to the arch-breaking pipe 200 . The gas source 300 is, for example, an air compressor or a compressed air storage tank.

[0052] Exemplarily, the waste residue discharge port 140 is connected to a silo pump 400, and the solid waste in the evaporation tower body 100 is discharged into the silo pump 400 through the waste residue discharge port 140. The silo pump 400 is used to transport the solid waste. The silo pump 400 is connected to the air source 300, and the air source 300 provides dry compressed air for the silo pump 400 to facilitate the silo pump 400 to discharge the solid waste.

[0053] Exemplarily, a valve body for controlling the opening or closing of the waste residue discharge outlet 140 is disposed at the waste residue discharge outlet 140 .

[0054] In the present application, by providing the arch-breaking pipe 200 and introducing compressed gas into the evaporation tower body 100 near the waste residue discharge port 140, the fluidity of the solid waste at the waste residue discharge port 140 is effectively improved. This helps to solve the problem of solid waste gathering at the waste residue discharge port and reduced fluidity in the prior art, so that the solid waste can be discharged from the waste residue discharge port 140 more smoothly.

[0055] In the present application, part of the arch-breaking pipe 200 is located in the evaporation tower body 100, and the flue gas in the evaporation tower is used to heat the arch-breaking pipe 200, thereby increasing the temperature of the compressed gas in the arch-breaking pipe 200. When the heated compressed gas is passed into the waste residue discharge port 140, the humidity of the solid waste can be reduced, and the fluidity of the solid waste is further improved, making it easier to discharge.

[0056] In the present application, the problem of solid waste accumulation and difficulty in discharge at the waste residue discharge port 140 is effectively solved by setting the arch breaking device, thereby optimizing the operating efficiency of the evaporation tower. This helps to reduce the downtime and maintenance cost of the evaporation tower and improve its overall performance and reliability. In addition, there is no need to add an additional heating source to the arch breaking pipe 200, saving energy.

[0057] like Figure 1 As shown, in one embodiment, the tube body on the broken arch tube 200 located in the evaporation tower body 100 is a heating tube segment 210, and the heating tube segment 210 is spirally coiled in the evaporation tower body 100, which increases the length of the heating tube segment 210 in the evaporation tower body 100, thereby increasing the contact area between the heating tube segment 210 and the flue gas, and improving the heating efficiency and heating effect of the compressed gas in the heating tube segment 210. Exemplarily, the heating tube segment 210 is fixedly connected to the inner wall of the evaporation tower body 100 by welding, bolting, clamping or riveting.

[0058] The heating pipe section 210 is located on the moving path of the flue gas that enters from the flue gas inlet 110 and is discharged from the flue gas outlet 120 to heat the waste liquid, so that the flue gas heats the compressed gas in the heating pipe section 210 .

[0059] In the present application, the portion of the broken arch tube 200 in the evaporation tower body 100 is the heating tube segment 210, and is spirally wound, which greatly increases the length of the heating tube segment 210 in the evaporation tower body 100. The increase in length means that the contact area between the heating tube segment 210 and the flue gas increases, thereby improving the heating efficiency of the flue gas on the compressed gas in the heating tube segment 210.

[0060] In the present application, since the heating pipe section 210 is located on the moving path of the smoke, the smoke directly heats the heating pipe section 210 during the flow process. This direct heating method allows the compressed gas in the heating pipe section 210 to heat up quickly, thereby enhancing the heating effect.

[0061] In the present application, the heating pipe section 210 adopts a spiral winding design, which improves the heating efficiency of the compressed gas, provides a sufficient heat source to reduce the humidity of the waste slag gathered at the waste slag discharge port 140, and reduces the situation where the waste slag is not discharged smoothly due to high humidity.

[0062] like Figure 1 As shown, in one embodiment, the evaporation tower body 100 includes an inlet section 102, a straight section 104 and a conical section 106, the inlet section 102, the straight section 104 and the conical section 106 are coaxially fixedly connected, the flue gas inlet 110 is arranged at the inlet section 102, the flue gas outlet 120 is arranged at the straight section 104, and the waste residue discharge outlet 140 is arranged at one end of the conical section 106 away from the straight section 104.

[0063] Along the first direction, the compressed gas outlet of the broken arch pipe 200 is arranged within a range of one quarter to one half of the height of the conical cylinder section 106 . The first direction is parallel to the axis of the evaporation tower body 100 and points from the conical cylinder section 106 to the straight cylinder section 104 .

[0064] like Figure 1 As shown, the arch-breaking pipe 200 further includes an external pipe section 220 for connecting the outlet of compressed gas with the outlet of the heating pipe section 210 .

[0065] The compressed gas heated in the heating pipe section 210 is passed into the compressed gas outlet through the external pipe section 220 .

[0066] like Figure 1 As shown, the external pipe section 220 is located outside the evaporation tower body 100, and an air intake valve 600 is provided on the external pipe section 220 to open or close the external pipe section 220. When the air intake valve 600 is opened, the compressed gas can enter the evaporation tower body 100; when "bridge" occurs, the air intake valve 600 is opened to allow the compressed gas to enter the evaporation tower body 100. When the "bridge" is eliminated, the air intake valve 600 is closed.

[0067] Exemplarily, the air intake valve 600 is an automatic valve or a manual valve.

[0068] In the present application, the air inlet valve 600 is provided on the external pipe section 220, so that the compressed gas can be flexibly controlled to be introduced. When the "bridge" phenomenon occurs, the air inlet valve 600 can be quickly opened to allow the heated compressed gas to enter the evaporation tower body 100, effectively breaking the "bridge" and ensuring the smooth discharge of solid waste.

[0069] In the present application, the design of the external pipe section 220 effectively connects the heating pipe section 210 with the compressed gas outlet, making the structure of the entire arch breaking system more compact and simple. At the same time, the external pipe section 220 is arranged outside the evaporation tower body 100, which also facilitates the maintenance and overhaul of the air intake valve 600 and avoids the reduction of the service life of the air intake valve 600 due to high temperature.

[0070] In one embodiment, a heat-insulating component is disposed on the outer wall of the external pipe section 220 , and the heat-insulating component is used to reduce the heat loss of the compressed gas in the external pipe section 220 to the outside.

[0071] Exemplarily, the thermal insulation component is, for example, a thermal insulation film, a thermal insulation coating, a thermal insulation felt or a thermal insulation cotton.

[0072] In the present application, the heated compressed gas circulates in the external pipe section 220, and the gas carries a relatively high amount of heat. By providing a heat-insulating member on the outer wall of the external pipe section 220, the heat loss to the outside can be effectively reduced. This helps to improve the temperature stability of the compressed gas, ensuring that the heated gas can maintain a relatively high temperature before entering the evaporation tower body 100, thereby improving the heating efficiency and the arch-breaking effect.

[0073] In this application, reducing heat loss means that more heat can be effectively used instead of being wasted in the heating process. This helps to improve the energy efficiency of the entire system, reduce energy consumption, and meet the requirements of modern industry for energy conservation, emission reduction and green development.

[0074] In the present application, high-temperature gas flows in the external pipe section 220. If the temperature of the external pipe section 220 is affected by the external atmospheric temperature and is relatively low, certain thermal stress or thermal damage may be caused to the external pipe section 220. The provision of the heat preservation member can play a certain heat preservation role, reduce the temperature difference between the inner and outer surfaces of the heating pipe section 210, and extend the service life of the external pipe section 220.

[0075] like Figure 1 As shown, in one embodiment, the evaporation tower body 100 is disposed vertically, and the axis of the evaporation tower body 100 is vertical.

[0076] Along the first direction, the inlet of the heating pipe segment 210 is arranged in the range of one quarter to one half of the height of the straight tube segment 104. Compared with setting the heating pipe segment 210 at a position above one half of the height of the straight tube segment 104, the setting position of the heating pipe segment 210 in the present application can prevent the waste liquid that is not completely vaporized and evaporated from falling onto the heating pipe segment 210, causing the heating pipe segment 210 to cool down, because when the waste liquid falls from the waste liquid inlet 130 to one half of the axial length direction of the evaporation tower body 100, the waste liquid has basically evaporated, and will not have a significant impact on the heat of the flue gas absorbed by the heating pipe segment 210.

[0077] like Figure 1 As shown, in one embodiment, the compressed gas outlet of the broken arch pipe 200 is arranged at the conical cylinder section 106 , and the compressed gas outlet includes a first outlet 230 and a second outlet 240 . The opening direction of the first outlet 230 is arranged along the radial direction of the conical cylinder section 106 .

[0078] The inner wall of the conical cylinder section 106 is the inner wall of a conical wall, and the opening direction of the second outlet 240 is arranged along the inner wall of the conical cavity and toward the waste residue discharge outlet 140 .

[0079] In the present application, the opening direction of the first outlet 230 is set along the radial direction of the conical cylinder section 106, which means that the compressed gas can be radially sprayed along the cavity wall, effectively covering and acting on the material near the cavity wall, and promoting the flow and discharge of the material.

[0080] In the present application, the opening direction of the second outlet 240 is arranged along the inner wall of the conical cavity and toward the waste discharge outlet 140. This arrangement helps to concentrate the force of the compressed gas in the direction of the waste discharge outlet 140, further pushing the material to move toward the waste discharge outlet 140, thereby improving the discharge efficiency.

[0081] In the present application, the first outlet 230 and the second outlet 240 spray compressed gas in two different directions, which increases the disturbance of the solid waste, thereby increasing the fluidity of the solid waste, and can also increase the contact area between the high-temperature compressed gas and the solid waste, thereby improving the dehumidification efficiency of the solid waste.

[0082] like Figure 1 and Figure 2 As shown, in one embodiment, at least two compressed gas outlets are provided, and the at least two compressed gas outlets are equidistantly distributed around the cone section 106; illustratively, two compressed gas outlets are provided; in another embodiment, three compressed gas outlets are provided. Of course, in another embodiment, other numbers of compressed gas outlets may be provided, such as four, five or six.

[0083] In the second aspect, the embodiment of the present application further provides an evaporation tower arch breaking method. In this embodiment, the waste liquid is desulfurization wastewater as an example to illustrate the technical solution. The method includes:

[0084] S100: spraying waste liquid into the evaporation tower body 100; introducing flue gas into the evaporation tower body 100, the flue gas heats the waste liquid, so that the water in the waste liquid evaporates into steam and is discharged from the evaporation tower body 100 with the flue gas, and at the same time, the solid waste remaining after the waste liquid evaporates is discharged from the evaporation tower body 100; the flue gas inlet 110 of the evaporation tower provided in the embodiment of the present application is used to introduce flue gas into the evaporation tower body 100, and the solid waste is discharged from the evaporation tower body 100 through the waste residue discharge port 140.

[0085] S200: intermittently or continuously introduce compressed gas into the solid waste concentration area in the evaporation tower body 100 through the arch-breaking pipe 200 to increase the fluidity of the solid waste; illustratively, the solid waste concentration area in the evaporation tower body 100 is the conical cylinder section 106. The arch-breaking pipe 200 of the evaporation tower provided in the embodiment of the present application is used to introduce compressed gas into the evaporation tower body 100.

[0086] S300: spirally coil the arch-breaking pipe 200 and fix it in the evaporation tower body 100, heat the arch-breaking pipe 200 by flue gas to heat the compressed gas in the arch-breaking pipe 200, and the heated compressed gas can heat the solid waste to reduce the humidity of the solid waste. This step is achieved by the arch-breaking pipe 200 of the evaporation tower provided by the embodiment of the present application.

[0087] S400: The length of the broken arch pipe 200 in the evaporation tower is L.

[0088] in:

[0089] d is the diameter of the broken arch pipe 200, in m;

[0090] Q is the total flue gas flow rate, in kg / h;

[0091] Q0 is the evaporation treatment capacity of desulfurization wastewater concentrate per unit time, in t / h;

[0092] Q1 is the flue gas consumption for evaporating 1 ton of desulfurization wastewater concentrate, in kg / h;

[0093] K is the total heat transfer coefficient, and the empirical value is set to 800-1000W / m 2 .℃;

[0094] Δt1 is the temperature difference between the flue gas inlet and outlet, in °C;

[0095] Δt2 is the temperature difference between the inlet and outlet of the compressed gas, in °C.

[0096] C3 is the specific heat capacity of flue gas, which is 1.122KJ / (kg.℃);

[0097] The derivation process of the above formula is as follows:

[0098] (I) Calculate the heat absorbed by wastewater concentration and vaporization.

[0099] The heat absorbed in the heating stage is q1=C1M△T=4.2*1*(100-25)=315KJ, that is, 1kg of 25℃ concentrated liquid absorbs 315KJ when heated to 100℃, and 1 ton of 25℃ concentrated liquid absorbs 3.15*10 5 KJ = 87.5 KWh;

[0100] Water evaporation phase change absorbs heat q2=△Q * =2257KJ, that is, the heat absorbed by evaporation of 1kg 100℃ concentrated liquid is 2257KJ, so the heat absorbed by evaporation of 1 ton of concentrated liquid is 2.257*10 6 KJ = 626.94 KWh;

[0101] The outlet temperature of the drying tower is not less than 150℃. The heat absorbed by 1 ton of water vapor from 100℃ to 150℃ is q3=7.06*10 4 KJ = 19.61 KWh;

[0102] The heat loss is calculated as 15%, so the heat absorbed by 1 ton of concentrated liquid from 25°C to 150°C water vapor is q = (q1 + q2 + q3) * (1 + 15%) = 844.16 KWh;

[0103] (ii) Calculate the amount of flue gas consumed when 1 ton of wastewater concentrate absorbs heat from 25°C to become water vapor at 150°C.

[0104] The flue gas is cooled from 330℃ to 150℃, q=C2*M*Δt1, where q is the heat absorbed by 1 ton of concentrated liquid when it changes from 25℃ to 150℃ water vapor, q=844.16KWh; C2 is the constant-pressure specific heat of flue gas, and the specific heat of flue gas is taken as 1.122KJ / (kg.℃); the inlet temperature of high-temperature flue gas is 330℃, and the outlet temperature is 150℃; then, the amount of flue gas required to change 1 ton of concentrated liquid from 25℃ to 150℃ water vapor is M=q / C2*Δt1=844.16*3600 / [1.122*(330-150)]=15047kg.

[0105] (III) Calculate the heat exchange area of ​​compressed air pipeline.

[0106] (1) Heat transfer area

[0107] Where Q2 is the amount of flue gas that can be used to heat compressed air, kg / h;

[0108] C3---Specific heat capacity of flue gas, take 1.122KJ / (kg.℃);

[0109] Δt1---temperature difference between inlet and outlet of high-temperature flue gas, °C;

[0110] K---total heat transfer coefficient, the empirical value is set to 800-1000W / m 2 .℃;

[0111] Δt m ---Average heat transfer temperature difference, °C;

[0112] (2) Average heat transfer temperature difference

[0113] Δt1---temperature difference between inlet and outlet of high-temperature flue gas, °C;

[0114] Δt2---compressed air temperature difference, °C;

[0115] (3) Compressed air heating consumes flue gas flow Q2 = Q-Q0*Q1

[0116] In the above formula, Q---total flue gas flow, kg / h;

[0117] Q2---the amount of flue gas that can be used to heat compressed air, kg / h;

[0118] Q1---Amount of flue gas consumed per unit mass of wastewater concentrate, kg / h;

[0119] Q0---Evaporation treatment capacity of wastewater concentrate per unit time, t / h;

[0120] (4) Heat transfer area S = πdL

[0121] In the above formula, d is the diameter of the compressed air pipeline, m;

[0122] L--compressed air pipeline length, m;

[0123] (5) Combining the above four formulas, we can get

[0124] In the above formula, L---the length of the compressed air pipeline, m;

[0125] The heat exchange area takes into account the surplus, and the actual length needs to be set 15% more based on the calculation.

[0126] In one embodiment, the water content of the compressed gas introduced into the evaporation tower body 100 through the broken arch pipe 200 is less than 0.5 g / m 3 , that is, the gas supplied by the gas source 300 to the arch-breaking pipe 200 is dry compressed gas.

[0127] In one embodiment, Δt2≥130° C. The pressure P of the compressed gas is ≥0.5 MPa, and the gas source 300 should ensure that the gas pressure in the arch-breaking pipe 200 is at least 0.5 MPa.

[0128] It should be noted that, in the absence of conflict, the features in the embodiments of this application may be combined with each other.

[0129] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An evaporation tower, comprising an evaporation tower body (100), wherein the evaporation tower body (100) is provided with a flue gas inlet (110), a flue gas outlet (120), a waste liquid inlet (130) and a waste residue outlet (140), characterized in that: The evaporation tower further comprises an arch-breaking pipe (200), the arch-breaking pipe (200) being used to introduce compressed gas into the evaporation tower body (100) near the waste residue discharge port (140), the compressed gas being used to improve the fluidity of solid waste at the waste residue discharge port (140), a portion of the arch-breaking pipe (200) being located in the evaporation tower body (100), the flue gas in the evaporation tower body (100) heating the arch-breaking pipe (200), so that the compressed gas in the arch-breaking pipe (200) is heated, and the heated compressed gas is used to reduce the humidity of solid waste at the waste residue discharge port (140).

2. The evaporation tower according to claim 1, characterized in that The pipe body on the broken arch pipe (200) located inside the evaporation tower body (100) is a heating pipe section (210); the heating pipe section (210) is spirally coiled inside the evaporation tower body (100); the heating pipe section (210) is located on a moving path of flue gas, so that the flue gas heats the compressed gas inside the heating pipe section (210).

3. The evaporation tower according to claim 2, characterized in that: The evaporation tower body (100) comprises an inlet section (102), a straight section (104) and a conical section (106); the inlet section (102), the straight section (104) and the conical section (106) are coaxially fixedly connected; the flue gas inlet (110) is arranged at the inlet section (102); the flue gas outlet (120) is arranged at the straight section (104); and the waste residue discharge outlet (140) is arranged at an end of the conical section (106) away from the straight section (104); Along a first direction, the compressed gas outlet of the arch-breaking pipe (200) is arranged within a range of one quarter to one half of the height of the conical cylinder section (106), and the first direction is parallel to the axis of the conical cylinder section (106) and points from the conical cylinder section (106) to the straight cylinder section (104); The arch-breaking pipe (200) further comprises an external pipe section (220) for connecting the compressed gas outlet with the outlet of the heating pipe section (210), and the compressed gas heated in the heating pipe section (210) is passed into the compressed gas outlet through the external pipe section (220); The external pipe section (220) is located outside the evaporation tower body (100), and an air intake valve (600) for opening or closing the external pipe section (220) is provided on the external pipe section (220).

4. The evaporation tower according to claim 3, characterized in that A heat-insulating component is provided on the outer wall of the external pipe section (220), and the heat-insulating component reduces the heat loss of the compressed gas in the external pipe section (220) to the outside.

5. The evaporation tower according to claim 3, characterized in that: Along the first direction, the inlet of the heating pipe section (210) is arranged within a range of one quarter to one half of the height of the straight tube section (104).

6. The evaporation tower according to claim 3, characterized in that: The compressed gas outlet of the broken arch pipe (200) is arranged at the conical cylinder section (106), and the compressed gas outlet comprises a first outlet (230) and a second outlet (240), and the opening direction of the first outlet (230) is arranged along the radial direction of the conical cylinder section (106); The inner wall of the cone section (106) is the inner wall of the conical cavity, and the opening direction of the second outlet (240) is arranged along the inner wall of the conical cavity of the cone section (106) and faces the waste slag discharge outlet (140).

7. The evaporation tower according to any one of claims 3 to 6, characterized in that: The arch-breaking pipe (200) is provided with at least two compressed gas outlets.

8. A method for breaking an arch of an evaporation tower, comprising spraying waste liquid into an evaporation tower body (100), introducing flue gas into the evaporation tower body (100), the flue gas heating the waste liquid to evaporate water in the waste liquid into steam, the steam being discharged from the evaporation tower body (100) along with the flue gas, and the solid waste remaining after the waste liquid evaporates being discharged from the evaporation tower body (100); It is characterized in that The method further includes: Intermittently or continuously introducing compressed gas into the solid waste concentration area in the evaporation tower body (100) through the broken arch pipe (200) to increase the fluidity of the solid waste; The arch-breaking pipe (200) is spirally coiled and fixed in the evaporation tower body (100), and the arch-breaking pipe (200) is heated by flue gas to heat the compressed gas in the arch-breaking pipe (200), and the heated compressed gas can heat the solid waste to reduce the humidity of the solid waste; The length of the broken arch pipe (200) in the evaporation tower is L. in: d is the diameter of the broken arch pipe (200), in m; Q is the total flue gas flow rate, in kg / h; Q1 is the flue gas consumption of evaporating 1 ton of waste liquid concentrate, in kg / h; Q0 is the evaporation treatment capacity of wastewater concentrate per unit time, in t / h; C3 is the specific heat capacity of flue gas, which is 1.122KJ / (kg.℃) at 300℃; K is the total heat transfer coefficient, and the empirical value is set to 800-1000W / m 2 .℃; Δt1 is the temperature difference between the flue gas inlet and outlet, in °C; Δt2 is the temperature difference between the inlet and outlet of the compressed gas, in °C.

9. The evaporation tower arch breaking method according to claim 8, characterized in that: The water content of the compressed gas introduced into the evaporation tower body (100) through the arch-breaking pipe (200) is less than 0.5 g / m 3 .

10. The evaporation tower arch breaking method according to claim 8, characterized in that: in, Δt2≥130℃, compressed gas pressure P≥0.5MPa.

Images