A wastewater recovery mechanism for sewage stripping in a C3C4 combined dehydrogenation unit

Abstract

The present invention relates to the technical field of wastewater recovery mechanisms for sewage stripping in a C3C4 combined dehydrogenation device, and specifically to a wastewater recovery mechanism for sewage stripping in a C3C4 combined dehydrogenation device, which includes a stripping tower body. A pressurization section is provided at the top of the stripping tower body, and a condensation section is connected to the top of the pressurization section. The pressurization section includes a low-pressure cavity provided at its lower end. The low-pressure cavity is connected to the top of the stripping tower body through a constant-pressure exhaust valve, and the low-pressure cavity is connected to a high-pressure transfer tank through a pressurization mechanism. The outlet of the high-pressure transfer tank is connected to the condensation section. In the present invention, the pressurization mechanism in the pressurization section at the top of the stripping tower body can pressurize and cool the generated H2S-containing gas, forming a state where the gas at the top of the stripping tower body is pressurized but not heated, enabling the H2S-containing gas to be simultaneously cooled by both condensation heat exchange and reduced expansion internal energy, cooling more rapidly, allowing the steam to condense more quickly, preventing the H2S concentration from being too high, and thus preventing pipeline corrosion.

Description

Technical Field

[0001] The present invention relates to the technical field of combined dehydrogenation of C3 and C4, and specifically to a wastewater recovery mechanism for sewage stripping in a C3C4 combined dehydrogenation device. Background Art

[0002] The C3C4 combined dehydrogenation device adopts the CATOFIN dehydrogenation process technology to produce propylene and isobutene. The device raw materials are propane and isobutane from the n-butane isomerization device or the tank farm, and C4 after MTBE from the MTBE device. After dehydrogenation reaction, product compression, product drying, low-temperature recovery, and product separation processes, the main products are hydrogen-rich gas, propylene, and C4 liquefied gas. Among them, the hydrogen-rich gas is sent to the PSA device, and the gas after hydrogen removal is returned to the dehydrogenation device. Propylene is directly sent to the tank farm, and C4 liquefied gas is sent to the MTBE device as its raw material.

[0003] The following problems exist in the prior art:

[0004] The MTBE device adopts a fixed-bed etherification reaction plus catalytic distillation technology. Using C4 liquefied gas and industrial methanol as raw materials, after etherification reaction, reactive distillation, and product separation, in addition to producing MTBE, high-purity MTBE, and C4 after ether, it also generates sewage with high sulfur components. The sewage is sent to the stripping tower, and hydrogen sulfide in it is removed by steam, and then the wastewater is recovered by condensation. During the stripping process, there is a high content of H2S at the top of the tower. When H2S exists in a gaseous state, the corrosiveness is very small. However, in the condensation area, especially after liquid water vapor appears in the initial condensation area, a wet hydrogen sulfide corrosion environment is formed, causing corrosion of these parts, mainly H2S-H2O type corrosion. As most of the water vapor condenses, the concentration of H2S will decrease, and the corrosion will also slow down. Therefore, the pipeline in the initial condensation area is severely corroded and leaks every time it operates for a period of time, resulting in shutdown. Summary of the Invention

[0005] The purpose of the present invention is to provide a wastewater recovery mechanism for sewage stripping in a C3C4 combined dehydrogenation device to solve the problems raised in the above background art.

[0006] The technical solution of the present invention is: a wastewater recovery mechanism for sewage stripping in a C3C4 combined dehydrogenation device, including a stripping tower body. A pressurization section is provided at the top of the stripping tower body, and a condensation section is connected to the top of the pressurization section;

[0007] The pressurization section includes a low-pressure cavity provided at its lower end. The low-pressure cavity is connected to the top of the stripping tower body through a constant-pressure exhaust valve, and the low-pressure cavity is connected to a high-pressure transfer tank through a pressurization mechanism. The outlet of the high-pressure transfer tank is connected to the condensation section. A cooling cavity is provided in the middle of the pressurization section, and the high-pressure transfer tank is located at the cooling cavity.

[0008] Furthermore, the boosting mechanism comprises an air cylinder, a piston plate is slidably arranged in the air cylinder, and a piston rod is connected to one side of the piston plate;

[0009] The outer rotating sleeve of the piston rod is provided with a gear sleeve, one side of the gear sleeve is connected to a driving mechanism, and the outer rotating sleeve is connected to a bracket, the bracket is fixedly arranged on the boosting section, one side of the gear sleeve is connected to a synchronous ring whose centers coincide with each other, one side of the synchronous ring is provided with a slider, and one side of the slider is slidably connected to a bevel plate;

[0010] The outlet of the gas cylinder is connected to the high-pressure transfer tank through an outlet one-way valve. The piston rod is a hollow structure, and an inlet one-way valve is arranged inside the piston rod. The end of the piston rod away from the gas cylinder extends into the low-pressure cavity.

[0011] Furthermore, an exhaust gate valve is provided on the top of the high-pressure transfer tank, and the outlet of the exhaust gate valve is connected to the condensation section;

[0012] A valve stem is slidably arranged in the middle of the exhaust gate valve, one end of the valve stem is connected to a driving mechanism, and the driving mechanism is used to control the opening and closing of the valve stem.

[0013] Furthermore, the driving mechanism includes a main shaft rotatably arranged in the middle of the supercharging section, a gear ring is fixedly arranged at one end of the main shaft, and a convex tooth is arranged on one half of the outer circumference of the gear ring, and the convex tooth is meshed and connected with the gear sleeve;

[0014] The end of the main shaft away from the gear ring is fixedly connected with a cam ring, and one half of the cam ring is a raised portion, and the position of the raised portion of the cam ring corresponds to the position of the convex teeth of the gear ring, and the cam ring is slidably matched with the valve stem;

[0015] A second bevel gear is fixedly sleeved on the main shaft, one side of the second bevel gear is vertically meshed with the first bevel gear, and the first bevel gear is connected to the motor through a transmission shaft.

[0016] Furthermore, there are multiple high-pressure transfer tanks, each of which is independently provided with a pressurizing mechanism at the bottom, and the multiple high-pressure transfer tanks are distributed in the pressurizing section around the main axis as the center.

[0017] Furthermore, an overflow pipe is connected to one side of the high-pressure transfer tank, an overflow constant pressure valve is connected between the overflow pipe and the high-pressure transfer tank, and one end of the overflow pipe away from the high-pressure transfer tank is connected to the low-pressure cavity.

[0018] Furthermore, a first partition plate, a second partition plate, and a third partition plate are sequentially arranged from top to bottom in the pressurization section. The first partition plate, the second partition plate, and the third partition plate divide the inner cavity of the pressurization section into four sections. Among them, the cam ring and the valve stem are located in the cavity of the uppermost section, the low-pressure cavity is located in the cavity of the lowermost section, the pressurization mechanism is located in the cavity of the section between the second partition plate and the third partition plate, and the cavity of the section between the first partition plate and the second partition plate forms a cooling cavity. The cooling cavity is used for preheating the sewage, and water inlets and water outlets are respectively connected to both sides of the cavity of the section between the first partition plate and the second partition plate;

[0019] A first heat conduction fin is arranged in the cavity of the section between the first partition plate and the second partition plate.

[0020] Furthermore, a steam inlet is arranged at the bottom on one side of the stripping tower body, a liquid discharge port is arranged at the bottom of the stripping tower body, and a sewage inlet is arranged at the top on one side of the stripping tower body. The sewage inlet is communicated with the water outlet.

[0021] Furthermore, a plurality of diversion pipes and heat exchange pipes are vertically arranged in the condensation section. The diameter of the diversion pipe is smaller than that of the heat exchange pipe, and the diversion pipe is inserted into the heat exchange pipe. A gap is provided between the upper ends of the diversion pipe and the heat exchange pipe, and exhaust holes and discharge ports are respectively communicated with the lower ends of the diversion pipe and the heat exchange pipe. The exhaust hole is communicated with the outlet of the exhaust gate valve.

[0022] Furthermore, a radiator is arranged at the top of the condensation section, and heat dissipation pipes are arranged on the radiator. The two ends of the heat dissipation pipe are respectively communicated with both sides of the condensation section.

[0023] The present invention hereby provides a wastewater recovery mechanism for sewage stripping in a C3C4 combined dehydrogenation device through improvement. Compared with the prior art, the following improvements and advantages are achieved:

[0024] First: In the present invention, the pressurization mechanism in the pressurization section at the top of the stripping tower body can pressurize the generated H2S-containing gas. The pressurized gas enters the high-pressure transfer tank, increasing the internal energy of the gas. At the same time, the cooling cavity in the pressurization section cools the high-pressure transfer tank, reducing the temperature of the gas entering the high-pressure transfer tank, forming a state where the gas pressure increases but the temperature does not increase compared to the gas at the top of the stripping tower body. In this state, the H2S-containing gas quickly releases from the high-pressure transfer tank and enters the condensation section, where it will be simultaneously cooled by condensation heat exchange and the reduction of expansion internal energy, achieving a faster cooling rate, greatly shortening the initial condensation state time of the steam, allowing the steam to condense in large quantities more quickly, preventing the H2S concentration from being too high, and thus preventing pipeline corrosion;

[0025] Second: In the present invention, by providing a low-pressure cavity in the pressurization section, when the air pressure at the top of the stripping tower body is too high, it can be released into the low-pressure cavity, so that the air pressure at the top of the stripping tower body will never be higher than the set value, avoiding excessive air pressure at the top of the stripping tower body, ensuring the air pressure stability of the stripping tower body, and further ensuring the separation efficiency of the tower. The pressurization mechanism pumps out the gas in the low-pressure cavity at a speed exceeding the intake speed of the low-pressure cavity to ensure that the inside of the low-pressure cavity is always in a low-pressure state, and at the same time ensure that the high-pressure transfer tank is always in a high-pressure state. The pressurization mechanism delivers gas to the high-pressure transfer tank with an excessive pressurization efficiency. When the pressure is higher than the set air pressure inside the high-pressure transfer tank, the excess gas enters the overflow pipe through the overflow pressure constant valve and returns to the low-pressure cavity from the overflow pipe to ensure the stability of the high-pressure state inside the high-pressure transfer tank, making the fluctuating air pressure all concentrated in the low-pressure cavity, ensuring the stability of the air pressure inside the high-pressure transfer tank, and making the gas output to the condensation section more stable, avoiding high and low fluctuations in air pressure, and thus ensuring the stability of the liquid level in the subsequent device at the same time;

[0026] Third: In the present invention, the operation of the pressurization mechanism and the opening and closing of the high-pressure transfer tank can both be driven by the driving mechanism. Specifically: the toothed ring drives the gear sleeve to rotate to achieve the automatic drive of the pressurization mechanism; the cam ring is driven by the main shaft to rotate. When the convex part rotates to the position of the valve rod, it can push the valve rod slidingly connected to it, so that the valve rod automatically closes the exhaust gate valve. When the non-convex part of the cam ring rotates to the position of the valve rod, it can pull the valve rod slidingly connected to it to automatically open the valve rod, realizing the automatic control of the opening and closing of the high-pressure transfer tank; moreover, the convex teeth of the toothed ring and the convex part of the cam ring are in corresponding positions, so that the high-pressure transfer tank will only replenish the input gas when it is in the closed state, and when it is in the open state, it can automatically release the gas, ensuring the synchronization of closing - inflating and opening - deflating. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further explained below with reference to the drawings and embodiments:

[0028] Figure 1 is the front view of the internal structure of the present invention;

[0029] Figure 2 is the front view of the internal structure of the pressurization section of the present invention;

[0030] Figure 3 is the front view of the internal structure of the condensation section of the present invention;

[0031] Figure 4 is the top view of the toothed ring of the present invention;

[0032] Figure 5 is the top view of the cam ring of the present invention;

[0033] Figure 6 is the top view of the heat exchange tube of the present invention;

[0034] Figure 7 is the top view of the radiator of the present invention;

[0035] Figure 8 is the front view of the present invention.

[0036] Description of the reference numerals in the drawings: 1, stripping tower body; 11, steam inlet; 12, liquid discharge port; 13, sewage inlet; 2, pressurization section; 21, pressurization mechanism; 211, gear sleeve; 212, synchronous ring; 213, slider; 214, inclined plane disk; 215, air cylinder; 216, piston plate; 217, piston rod; 218, bracket; 219, intake check valve; 220, outlet check valve; 22, high-pressure transfer tank; 221, overflow pipe; 222, overflow constant pressure valve; 223, exhaust gate valve; 2231, valve stem; 23, water inlet; 24, water outlet; 25, first partition; 26, second partition; 27, third partition; 28, driving mechanism; 281, motor; 282, first bevel gear; 283, second bevel gear; 284, main shaft; 285, tooth ring; 286, transmission shaft; 287, cam ring; 29, low-pressure cavity; 291, constant pressure exhaust valve; 210, first heat conduction fin; 3, condensation section; 31, heat exchange tube; 32, diversion tube; 33, exhaust hole; 34, discharge port; 35, radiator; 351, heat dissipation tube. Detailed implementation manners

[0037] The present invention will be described in detail below. The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0038] The present invention provides a wastewater recovery mechanism for sewage stripping of a C3C4 combined dehydrogenation device through improvement, as Figures 1 - 8 shown, a wastewater recovery mechanism for sewage stripping of a C3C4 combined dehydrogenation device includes a stripping tower body 1. A pressurization section 2 is arranged at the top of the stripping tower body 1, and a condensation section 3 is connected to the top of the pressurization section 2; the sulfur-containing gas generated by stripping is condensed through the condensation section 3 to achieve wastewater recovery;

[0039] The pressurization section 2 includes a low-pressure cavity 29 arranged at its lower end. The low-pressure cavity 29 is connected to the top of the stripping tower body 1 through a constant pressure exhaust valve 291, and the low-pressure cavity 29 is connected to a high-pressure transfer tank 22 through a pressurization mechanism 21. The outlet of the high-pressure transfer tank 22 is connected to the condensation section 3. A cooling cavity is arranged in the middle of the pressurization section 2, and the high-pressure transfer tank 22 is located at the cooling cavity; the cooling cavity can be connected to a circulating water cooling device for cooling.

[0040] The pressurizing mechanism 21 in the pressurizing section 2 at the top of the stripping tower body 1 can pressurize the generated H2S-containing gas. The pressurized gas enters the high-pressure transfer tank 22, increasing the internal energy of the gas. At the same time, the cooling cavity in the pressurizing section 2 cools the high-pressure transfer tank 22, reducing the temperature of the gas entering the high-pressure transfer tank 22, forming a state where the gas is pressurized but not heated compared to the top of the stripping tower body 1. In this state, the H2S-containing gas quickly releases from the high-pressure transfer tank 22 into the condensation section 3, and will simultaneously be cooled by both condensation heat transfer and the reduction of expansion internal energy, achieving a faster temperature drop, greatly shortening the initial condensation state time of the steam, allowing the steam to condense in large quantities more quickly, preventing the H2S concentration from being too high, and thus preventing pipeline corrosion.

[0041] The pressurizing mechanism 21 includes a cylinder 215. A piston plate 216 is slidably arranged in the cylinder 215, and a piston rod 217 is connected to one side of the piston plate 216;

[0042] A gear sleeve 211 is rotatably sleeved outside the piston rod 217. A driving mechanism 28 is connected to one side of the gear sleeve 211. The gear sleeve 211 is rotatably connected to a bracket 218 outside, and the bracket 218 is fixedly arranged on the pressurizing section 2. A synchronous ring 212 with the same center is connected to one side of the gear sleeve 211. A slider 213 is arranged on one side of the synchronous ring 212. A slope plate 214 is slidably connected to one side of the slider 213, and the upper surface of the slope plate 214 is an inclined surface;

[0043] The outlet of the cylinder 215 is connected to the high-pressure transfer tank 22 through an outlet check valve 220. The piston rod 217 is of a hollow structure, and an inlet check valve 219 is arranged inside the piston rod 217. And one end of the piston rod 217 away from the cylinder 215 extends into the low-pressure cavity 29. When the gear sleeve 211 rotates, it can drive the slider 213 to rotate. The slider 213 slides along the inclined surface at the top of the slope plate 214, thereby driving the slope plate 214 to move up and down. The slope plate 214 drives the piston rod 217 and the piston plate 216 to move up and down synchronously. Under the restrictive action of the outlet check valve 220 and the inlet check valve 219, the gas inside the low-pressure cavity 29 can be continuously pumped into the high-pressure transfer tank 22.

[0044] An exhaust gate valve 223 is arranged at the top of the high-pressure transfer tank 22, and the outlet of the exhaust gate valve 223 is communicated with the condensation section 3;

[0045] A valve rod 2231 is slidably arranged in the middle of the exhaust gate valve 223. One end of the valve rod 2231 is connected to a driving mechanism 28, and the driving mechanism 28 is used to control the opening and closing of the valve rod 2231. Controlling the opening and closing of the valve rod 2231 can control the opening and closing of the high-pressure transfer tank 22.

[0046] The driving mechanism 28 includes a main shaft 284 rotatably arranged in the middle of the supercharging section 2, a gear ring 285 is fixedly arranged at one end of the main shaft 284, and a convex tooth is arranged on one half of the outer circumference of the gear ring 285, and the convex tooth is meshed with the gear sleeve 211; the gear ring 285 drives the gear sleeve 211 to rotate, thereby realizing automatic driving of the supercharging mechanism 21;

[0047] A cam ring 287 is fixedly connected to one end of the main shaft 284 away from the gear ring 285, and one half of the cam ring 287 is a raised portion, and the position of the raised portion of the cam ring 287 corresponds to the position of the raised teeth of the gear ring 285, and the cam ring 287 is slidably matched with the valve stem 2231; the cam ring 287 is driven to rotate by the main shaft 284, and when its raised portion rotates to the position of the valve stem 2231, it can push the valve stem 2231 slidably connected thereto, so that the valve stem 2231 automatically closes the exhaust gate valve 223 When the non-raised portion of the cam ring 287 rotates to the position of the valve stem 2231, it can pull the valve stem 2231 slidably connected thereto, allowing the valve stem 2231 to open automatically, thereby realizing automatic control of the opening and closing of the high-pressure transfer tank 22; and the convex teeth of the gear ring 285 and the raised portion of the cam ring 287 correspond to each other, so that the high-pressure transfer tank 22 will only replenish the input gas when it is in the closed state, and can automatically release the gas when it is in the open state, thereby ensuring the synchronization of closing-inflation and opening-deflation.

[0048] A second bevel gear 283 is fixedly sleeved on the main shaft 284 , one side of the second bevel gear 283 is vertically meshed with the first bevel gear 282 , and the first bevel gear 282 is transmission-connected to the motor 281 via a transmission shaft 286 .

[0049] There are multiple high-pressure transfer tanks 22, and a boosting mechanism 21 is independently provided at the bottom of each high-pressure transfer tank 22. The multiple high-pressure transfer tanks 22 are distributed in the boosting section 2 around the main axis 284 as the center. Since the high-pressure transfer tank 22 needs to store gas and then release gas, it is an intermittent operation. The multiple high-pressure transfer tanks 22 are opened and released alternately in turn, which reduces the single gas release volume and reduces the time interval between each gas release, so that the gas release process can be smoother and the stability of gas output can be improved.

[0050] An overflow pipe 221 is connected to one side of the high-pressure transfer tank 22, an overflow constant pressure valve 222 is connected between the overflow pipe 221 and the high-pressure transfer tank 22, and an end of the overflow pipe 221 away from the high-pressure transfer tank 22 is connected to the low-pressure cavity 29;

[0051] In the stripping column body 1, the stripping process is from bottom to top. Both the gas evaporated first and the gas evaporated later flow upward. The closer to the top of the tower, the greater the air pressure. Affected by the fluctuation of the light component content in the raw sewage, there is also a fluctuation in the air pressure at the top of the stripping column body 1, mainly the fluctuation of the air pressure increase. The increase in tower pressure is bound to affect the change of the gas-liquid equilibrium components on the trays, resulting in a decrease in the relative volatility between components and a reduction in the separation efficiency of the tower. Moreover, the fluctuation of the top pressure is not conducive to the control of the liquid level in the subsequent reflux tank. Once the liquid level in the tank in the downstream device fluctuates, it will be unfavorable for the gas-liquid and liquid-liquid separation in the reflux tank; by setting a low-pressure cavity 29 in the pressurization section 2, when the air pressure at the top of the stripping column body 1 is too high, it can be released into the low-pressure cavity 29, so that the air pressure at the top of the stripping column body 1 will never be higher than the set value, avoiding too high air pressure at the top of the stripping column body 1, ensuring the air pressure stability of the stripping column body 1, and then ensuring the separation efficiency of the tower. The pressurization mechanism 21 pumps out the gas in the low-pressure cavity 29 at a speed exceeding the intake speed of the low-pressure cavity 29 to ensure that the inside of the low-pressure cavity 29 is always in a low-pressure state, and at the same time ensure that the high-pressure transfer tank 22 is always in a high-pressure state. The pressurization mechanism 21 transports gas into the high-pressure transfer tank 22 with an excessive pressurization efficiency. When it is higher than the set air pressure inside the high-pressure transfer tank 22, the excess gas enters the overflow pipe 221 through the overflow air pressure constant valve 222 and returns to the low-pressure cavity 29 from the overflow pipe 221 to ensure the stability of the high-pressure state inside the high-pressure transfer tank 22, making the fluctuating air pressure all concentrated in the low-pressure cavity 29, ensuring the air pressure inside the high-pressure transfer tank 22, and making the gas output to the condensation section 3 more stable, avoiding high and low fluctuations of the air pressure, so as to ensure the stability of the liquid level in the downstream device at the same time.

[0052] In the pressurization section 2, a first partition plate 25, a second partition plate 26, and a third partition plate 27 are sequentially arranged from top to bottom. The first partition plate 25, the second partition plate 26, and the third partition plate 27 divide the cavity inside the pressurization section 2 into four sections. Among them, the cam ring 287 and the valve rod 2231 are located in the cavity of the uppermost section, the low-pressure cavity 29 is located in the cavity of the lowermost section, the pressurization mechanism 21 is located in the cavity between the second partition plate 26 and the third partition plate 27, and the cavity between the first partition plate 25 and the second partition plate 26 forms a cooling cavity for preheating the sewage. And water inlets 23 and water outlets 24 are respectively connected to both sides of the cavity between the first partition plate 25 and the second partition plate 26; the temperature of the raw sewage is relatively low. By introducing the raw sewage into the cooling cavity, the high-pressure transfer tank 22 can be cooled, so as to reduce the temperature of the high-pressure transfer tank 22. At the same time, the raw sewage is heated after heat exchange, which is beneficial to reducing the subsequent stripping burden and improving the stripping efficiency.

[0053] A first heat conduction fin 210 is arranged in the cavity between the first partition plate 25 and the second partition plate 26; the first heat conduction fin 210 can improve the heat exchange efficiency.

[0054] One side of the bottom of the stripping tower body 1 is provided with a steam inlet 11, the bottom of the stripping tower body 1 is provided with a liquid discharge port 12, and one side of the top of the stripping tower body 1 is provided with a sewage inlet 13, and the sewage inlet 13 is communicated with the water outlet 24; the steam inlet 11 is used for introducing high-temperature steam, the sewage inlet 13 is used for inputting raw sewage, and the liquid discharge port 12 is used for discharging the water after stripping.

[0055] A number of diversion pipes 32 and heat exchange pipes 31 are vertically arranged in the condensation section 3. The diameter of the diversion pipe 32 is smaller than that of the heat exchange pipe 31, and the diversion pipe 32 is inserted into the heat exchange pipe 31. There is a gap between the upper ends of the diversion pipe 32 and the heat exchange pipe 31, and the lower ends of the diversion pipe 32 and the heat exchange pipe 31 are respectively communicated with an exhaust hole 33 and a discharge port 34. The exhaust hole 33 is communicated with the outlet of the exhaust gate valve 223; the gas discharged from the high-pressure transfer tank 22 can enter the heat exchange pipe 31 and move in a zigzag path in the heat exchange pipe 31, and is fully cooled by heat exchange. The condensate and H2S gas are discharged from the discharge port 34.

[0056] A radiator 35 is arranged at the top of the condensation section 3. A heat dissipation pipe 351 is arranged on the radiator 35, and both ends of the heat dissipation pipe 351 are respectively communicated with both sides of the condensation section 3; the internal cooling water is pumped to circulate, and the circulating cooling water is used for heat exchange with the condensation section 3, and then the surface of the heat dissipation pipe 351 is blown by a fan, so that the natural air with reduced temperature exchanges heat with the heat dissipation pipe 351 to realize the heat dissipation of the condensation section 3.

[0057] Working principle: The raw sewage enters the top of the stripping tower body 1 from the sewage inlet 13 and flows downward, and the steam enters the bottom of the stripping tower body 1 from the steam inlet 11 and flows upward. The sewage contacts the steam, and the pollutants in it are stripped out. The pollutants enter the condensation section 3 after passing through the pressurization section 2 and are condensed to realize the recovery of the wastewater.

[0058] The sulfur-containing gas enters the pressurization section 2 from the top of the stripping tower body 1. A low-pressure cavity 29 is provided in the pressurization section 2, so that when the air pressure at the top of the stripping tower body 1 is too high, it can be released into the low-pressure cavity 29, ensuring that the air pressure at the top of the stripping tower body 1 is never higher than the set value, avoiding excessive air pressure at the top of the stripping tower body 1, guaranteeing the air pressure stability of the stripping tower body 1, and thus ensuring the separation efficiency of the tower. The pressurization mechanism 21 extracts the gas in it at a speed exceeding the intake of the low-pressure cavity 29 to ensure that the inside of the low-pressure cavity 29 is always in a low-pressure state, while ensuring that the high-pressure transfer tank 22 is always in a high-pressure state. The pressurization mechanism 21 conveys gas into the high-pressure transfer tank 22 with an excessive pressurization efficiency. When the pressure is higher than the set air pressure inside the high-pressure transfer tank 22, the excess gas enters the overflow pipe 221 through the overflow air pressure constant valve 222 and returns to the low-pressure cavity 29 from the overflow pipe 221 to ensure the stability of the high-pressure state inside the high-pressure transfer tank 22, concentrating all the fluctuating air pressure in the low-pressure cavity 29, ensuring the stability of the air pressure inside the high-pressure transfer tank 22, making the gas output to the condensation section 3 more stable, avoiding high and low fluctuations in air pressure, and thus ensuring the stability of the liquid level in the subsequent device at the same time;

[0059] The operation of the pressurization mechanism 21 and the opening and closing of the high-pressure transfer tank 22 can both be driven by the drive mechanism 28. Specifically: The toothed ring 285 drives the gear sleeve 211 to rotate to achieve the automatic drive of the pressurization mechanism 21; The cam ring 287 is driven to rotate by the main shaft 284. When its convex part rotates to the position of the valve stem 2231, it can push the valve stem 2231 that is slidably connected to it, causing the valve stem 2231 to automatically close the exhaust gate valve 223. When the non-convex part of the cam ring 287 rotates to the position of the valve stem 2231, it can pull the valve stem 2231 that is slidably connected to it, causing the valve stem 2231 to automatically open, realizing the automatic control of the opening and closing of the high-pressure transfer tank 22; Moreover, the convex teeth of the toothed ring 285 and the convex part of the cam ring 287 are in corresponding positions, so that the high-pressure transfer tank 22 will only supplement the input gas when it is in the closed state, and when it is in the open state, it can automatically release the gas, ensuring the synchronization of closing - inflating and opening - deflating.

Claims

1. A wastewater recovery mechanism for sewage stripping in a C3C4 combined dehydrogenation unit, characterized in that, Comprising: A stripping tower body (1), a pressurizing section (2) is arranged at the top of the stripping tower body (1), and a condensation section (3) is connected to the top of the pressurizing section (2); The pressurizing section (2) includes a low-pressure cavity (29) arranged at its lower end. The low-pressure cavity (29) is communicated with the top of the stripping tower body (1) through a constant-pressure exhaust valve (291), and the low-pressure cavity (29) is connected to a high-pressure transfer tank (22) through a pressurizing mechanism (21). The outlet of the high-pressure transfer tank (22) is communicated with the condensation section (3). A temperature reduction cavity is arranged in the middle of the pressurizing section (2), and the high-pressure transfer tank (22) is located at the temperature reduction cavity; In the pressurizing section (2), a first partition plate (25), a second partition plate (26) and a third partition plate (27) are sequentially arranged from top to bottom. The first partition plate (25), the second partition plate (26) and the third partition plate (27) divide the internal cavity of the pressurizing section (2) into four sections. The low-pressure cavity (29) is located in the cavity of the lowermost section. The pressurizing mechanism (21) is located in the cavity between the second partition plate (26) and the third partition plate (27). And the cavity between the first partition plate (25) and the second partition plate (26) forms a temperature reduction cavity for preheating sewage. And water inlets (23) and water outlets (24) are respectively connected to both sides of the cavity between the first partition plate (25) and the second partition plate (26). The temperature reduction cavity cools the high-pressure transfer tank (22) to reduce the temperature of the gas entering the high-pressure transfer tank (22), forming a state where the gas pressure increases but the temperature does not increase compared to the top of the stripping tower body (1); A steam inlet (11) is arranged at the bottom of one side of the stripping tower body (1), a liquid discharge port (12) is arranged at the bottom of the stripping tower body (1), and a sewage inlet (13) is arranged at the top of one side of the stripping tower body (1). The sewage inlet (13) is communicated with the water outlet (24).

2. The wastewater recovery mechanism for sewage stripping in a C3C4 combined dehydrogenation unit according to claim 1, characterized in that: The pressurizing mechanism (21) includes a cylinder (215), a piston plate (216) is slidably arranged in the cylinder (215), and a piston rod (217) is connected to one side of the piston plate (216); A gear sleeve (211) is rotatably sleeved outside the piston rod (217). A driving mechanism (28) is connected to one side of the gear sleeve (211), and a bracket (218) is rotatably connected outside the gear sleeve (211). The bracket (218) is fixedly arranged on the pressurizing section (2). A synchronous ring (212) with the same center is connected to one side of the gear sleeve (211). A slider (213) is arranged on one side of the synchronous ring (212), and a bevel disk (214) is slidably connected to one side of the slider (213); The outlet of the cylinder (215) is connected to the high-pressure transfer tank (22) through an air outlet check valve (220). The piston rod (217) is of a hollow structure, and an air inlet check valve (219) is arranged in the piston rod (217). And the end of the piston rod (217) far from the cylinder (215) extends into the low-pressure cavity (29).

3. The wastewater recovery mechanism for sewage stripping in a C3C4 combined dehydrogenation unit according to claim 2, characterized in that: An exhaust gate valve (223) is arranged at the top of the high-pressure transfer tank (22), and the outlet of the exhaust gate valve (223) is communicated with the condensation section (3); A valve stem (2231) is slidably disposed in the middle of the exhaust gate valve (223), and one end of the valve stem (2231) is connected to a driving mechanism (28), which is used to control the opening and closing of the valve stem (2231).

4. The wastewater recovery mechanism for sewage stripping in a C3C4 combined dehydrogenation unit according to claim 3, characterized in that: The driving mechanism (28) comprises a main shaft (284) rotatably arranged in the middle of the boosting section (2), a gear ring (285) being fixedly arranged at one end of the main shaft (284), and a convex tooth being arranged on one half of the outer circumference of the gear ring (285), and the convex tooth being meshedly connected with the gear sleeve (211); A cam ring (287) is fixedly connected to one end of the main shaft (284) away from the gear ring (285), and one half of the cam ring (287) is a raised portion, and the position of the raised portion of the cam ring (287) corresponds to the position of the convex teeth of the gear ring (285), and the cam ring (287) is slidably matched with the valve stem (2231); A second bevel gear (283) is fixedly sleeved on the main shaft (284), one side of the second bevel gear (283) is vertically meshed with the first bevel gear (282), and the first bevel gear (282) is transmission-connected to the motor (281) via a transmission shaft (286).

5. The wastewater recovery mechanism for sewage stripping in a C3C4 combined dehydrogenation unit according to claim 2, characterized in that: A plurality of high-pressure transfer tanks (22) are provided, and a pressurizing mechanism (21) is independently provided at the bottom of each high-pressure transfer tank (22). The plurality of high-pressure transfer tanks (22) are distributed in the pressurizing section (2) around the main axis (284) as the center of the circle.

6. The wastewater recovery mechanism for sewage stripping in a C3C4 combined dehydrogenation unit according to claim 2, characterized in that: An overflow pipe (221) is connected to one side of the high-pressure transfer tank (22), an overflow constant pressure valve (222) is connected between the overflow pipe (221) and the high-pressure transfer tank (22), and an end of the overflow pipe (221) away from the high-pressure transfer tank (22) is in communication with the low-pressure cavity (29).

7. The wastewater recovery mechanism for sewage stripping in a C3C4 combined dehydrogenation unit according to claim 4, characterized in that: The cam ring (287) and the valve stem (2231) are located in the uppermost cavity of the four cavities divided in the boost section (2), and a first heat-conducting fin (210) is provided in the cavity between the first partition plate (25) and the second partition plate (26).

8. The wastewater recovery mechanism for sewage stripping in a C3C4 combined dehydrogenation unit according to claim 3, characterized in that: A plurality of flow guide pipes (32) and heat exchange pipes (31) are vertically arranged in the condensing section (3); the diameter of the flow guide pipe (32) is smaller than that of the heat exchange pipe (31), and the flow guide pipe (32) is inserted into the heat exchange pipe (31); a gap is provided between the upper end of the flow guide pipe (32) and the upper end of the heat exchange pipe (31); and the lower ends of the flow guide pipe (32) and the heat exchange pipe (31) are respectively connected to an exhaust hole (33) and a discharge port (34); and the exhaust hole (33) is connected to an outlet of an exhaust gate valve (223).

9. The wastewater recovery mechanism for sewage stripping in a C3C4 combined dehydrogenation unit according to claim 8, characterized in that: A radiator (35) is provided on the top of the condensing section (3), a heat dissipation pipe (351) is provided on the radiator (35), and two ends of the heat dissipation pipe (351) are respectively connected to two sides of the condensing section (3).

Images