Desulfurization slurry flash evaporation condensate water non-condensable gas vacuumizing device based on absorption method

Abstract

The utility model discloses a desulfurization slurry flash evaporation condensate water non-condensable gas vacuumizing device based on an absorption method, and belongs to the technical field of chemical processes and waste heat recovery heat supply. In order to solve the problems that a large amount of non-condensable gas such as SO2 escapes due to heat release and condensation during flash evaporation waste heat recovery of desulfurization slurry, the volume of equipment is large, and a high vacuum degree is difficult to maintain by adopting a conventional vacuum pump, a feed liquid spraying and absorption reaction dissolution method is adopted, and primary non-condensable gas rich in components such as SO2 is fed into a high-vacuum desulfurization tank; the non-condensable gas and feed liquid sprayed from the spraying device are removed and reduced through chemical reaction, physical absorption and dissolution and other methods, the volume flow of the non-condensable gas is greatly reduced, the remaining non-condensable gas is discharged through the liquid-proof non-condensable gas discharging device and pumped out through a conventional vacuum pump, and high-vacuum-degree control is achieved. And the native non-condensable gas can enter from the upper part of the high-vacuum desulfurization tank and move downwards, or enter from the side lower part and move upwards. The device is also suitable for discharging other chemical multi-component non-condensable gases so as to maintain a high-vacuum-degree scene.

Description

Technical Field

[0001] The utility model relates to a vacuum pumping device for non-condensable gas in the flash condensate of desulfurized slurry based on the absorption method, belonging to the technical fields of chemical processes and waste heat recovery for heating. Background Art

[0002] When wet desulfurization methods are used for flue gas from coal-fired boilers, sintering machine flue gas in steel mills, etc., the desulfurized slurry contains a large amount of waste heat, which can be recovered and used to heat the return water of the heat network or other process water. This can not only reduce the heat loss of the system, but also reduce the fuel consumption and pollutant emissions such as greenhouse gases, and improve the thermal utilization efficiency of the main process system. Therefore, the development of flue gas waste heat recovery technology is an important way to help achieve the "dual carbon" strategic goal. In recent years, a method of flue gas waste heat recovery using desulfurized slurry flash evaporation + absorption heat pump has emerged, that is, the heat in the flue gas is taken out from the desulfurized slurry through a flash tank, and the flash steam is sent to the heat pump for waste heat recovery and to heat the return water of the heat network or other process water, while the concentrated liquid returns to the desulfurization circulating water. Its advantages are: there is no need to transform the flue gas system, reducing the on-site implementation difficulty; the quality of the condensate water is good, which is convenient for recycling. However, the disadvantages are also very obvious: the flue gas temperature can usually only be reduced to 42 - 45°C, recovering about half of the flue gas waste heat, which does not belong to deep heat recovery and can only be regarded as a half-finished project. There is still a large amount of flue gas waste heat escaping from the flue gas, and secondary transformation is still required in the future to achieve deep heat recovery. The cost calculated for the unit waste heat recovery amount is relatively high, and the investment payback period is long. The fundamental reasons why it cannot reduce the flue gas temperature to the 30°C level and achieve deep heat recovery are: firstly, the desulfurized slurry flash evaporation complete set of equipment is a vacuum equipment, its system integration is relatively complex, the guarantee requirements are high, and the lower the flash steam temperature, the larger the specific volume, the larger the equipment volume, and the higher the cost; secondly, a large amount of non-condensable gases such as SO2 will escape during the desulfurized slurry flash evaporation process. The flash steam is sent to the absorption heat pump, and it is difficult to pump the vacuum during the condensation and heat release process in the horizontal evaporator of the heat pump. The absolute pressure during actual operation can only be maintained at about 7 - 8 kPa. It is very difficult to further improve the vacuum degree with the existing equipment and conditions, and it cannot improve the vacuum degree like a normal condenser. Therefore, the saturation temperature of the flash steam can only be reduced to the 38 - 40°C level, resulting in the flue gas temperature can only be reduced to the 40 - 45°C level.

[0003] In addition, in process production such as chemical plants, the non-condensable gas discharged often contains multiple components, and the large flow rate makes it difficult to ensure a higher vacuum degree for the equipment. If some of the components can be removed by chemical reactions or physical dissolution, absorption and other methods with lye or other chemicals, the flow rate of the remaining non-condensable gas will be significantly reduced, and it is easier to achieve a higher vacuum degree operation with a conventional vacuum pump to improve the process operation conditions and obtain energy-saving and cost-saving benefits. Summary of the Utility Model

[0004] The object and task of the present utility model are, in view of the existing inherent technical limitations in the current waste heat recovery system using the desulfurized slurry flashing method, to remove some components such as SO2 by using alkali liquid or other agents through chemical reactions or physical dissolution, absorption and other methods, so as to achieve high-vacuum operation by using a conventional vacuum pump.

[0005] The specific description of the present utility model is: A vacuum pumping device for non-condensable gas in the condensate water of desulfurized slurry flashing based on the absorption method, which is composed of a high-vacuum desulfurization tank 1, a conventional vacuum pump 7 and other connecting pipelines and components. It is characterized in that a liquid spraying device 3, a liquid-proof non-condensable gas discharging device 2, a liquid level measurement and control assembly 4, a spraying reaction zone enriched with high-concentration non-condensable gas S1, a gas collection zone enriched with remaining non-condensable gas S2 and a bottom liquid storage zone are arranged inside the high-vacuum desulfurization tank 1. Among them, the non-condensable gas inlet of the spraying reaction zone enriched with high-concentration non-condensable gas S1 is communicated with the gas transmission pipe of the primary non-condensable gas S0; the gas outlet of the liquid-proof non-condensable gas discharging device 2 is connected with the inlet of the conventional vacuum pump 7, and the outlet of the conventional vacuum pump 7 is communicated with the exhaust pipe for discharging non-condensable gas Sn; the feed inlet of the liquid spraying device 3 is connected with the outlet of the liquid pump 5, and the inlet of the liquid pump 5 is communicated with the liquid transmission pipe of the liquid Na; the liquid level probe of the liquid level measurement and control assembly 4 is arranged below the liquid level of the bottom liquid storage zone, and the bottom liquid outlet of the bottom liquid storage zone is connected with the inlet of the liquid level regulating valve 6.

[0006] When the inlet of the primary non-condensable gas S0 entering the high-vacuum desulfurization tank 1 is arranged in the lower area of the liquid spraying device 3, the lower part of the liquid spraying device 3 is the spraying reaction zone enriched with high-concentration non-condensable gas S1, the upper part is the gas collection zone enriched with the remaining non-condensable gas S2, the liquid-proof non-condensable gas discharging device 2 is arranged above the liquid spraying device 3, the inlet of the liquid pump 5 is also connected with the inlet of the liquid level regulating valve 6, and the outlet of the liquid level regulating valve 6 is communicated with the drainage pipe of the reaction external drainage P.

[0007] When the primary non-condensable gas S0 is arranged at the top of the high-vacuum desulfurization tank 1, or when the inlet of the primary condensate water W1 mixed with the primary non-condensable gas entering the high-vacuum desulfurization tank 1 is arranged at the top of the high-vacuum desulfurization tank 1, the top space inside the high-vacuum desulfurization tank 1 is the gas collection zone of the primary non-condensable gas S0, the lower part thereof is the liquid spraying device 3, the lower part of the liquid spraying device 3 is the spraying reaction zone enriched with high-concentration non-condensable gas S1, then downward is the liquid-proof non-condensable gas discharging device 2, then downward is the gas collection zone enriched with the remaining non-condensable gas S2, and then downward is the bottom liquid storage zone; the outlet of the liquid pump 5 is also connected with the outlet of the condensate water circulation pump 8, the inlet of the condensate water circulation pump 8 is respectively connected with the bottom liquid outlet of the bottom liquid storage zone and the inlet of the liquid level regulating valve 6, and the outlet of the liquid level regulating valve 6 is communicated with the drainage pipe of the condensate external drainage W2.

[0008] The described conventional vacuum pump 7 adopts the structure of a water-ring vacuum pump, a water jet air ejector or a Roots vacuum pump.

[0009] The described liquid spraying device 3 and its lower region adopt a nozzle-type empty tower structure or a packing structure.

[0010] The liquid Na is a sodium hydroxide solution with a mass concentration range of 0% to 60% or other reactive agents.

[0011] The beneficial effects of the present utility model are as follows.

[0012] (1) For the raw non-condensable gas with a relatively large amount of SO2 components escaping from the condensate of the desulfurization slurry flash steam, by adopting the method of secondary desulfurization of the raw non-condensable gas, using agents such as sodium hydroxide to remove the reactive or absorbable and soluble components such as SO2 therein, the total amount of non-condensable gas can be greatly reduced, and the chemical absorption pre-vacuum pumping process can be realized.

[0013] Based on this, only a conventional vacuum pump is needed to greatly improve the vacuum degree of the high-vacuum desulfurization tank, thereby significantly improving the vacuum degree of the vacuum equipment for the main process, and providing better vacuum technical conditions for the main process production process and the flash steam waste heat recovery process.

[0014] (3) The power consumption and the like of the entire vacuum pumping equipment system including the high-vacuum desulfurization tank and the conventional vacuum pump are significantly reduced, and the initial investment and operation costs are reduced.

[0015] (4) The drained liquid after the reaction can also be further recycled for water resources and other liquid components, realizing circular economy.

[0016] (5) This patent can also be applied to occasions where the residual non-condensable gas to be discharged in the process production of chemical plants and the like needs to be reduced in quantity and high-vacuum control is achieved. Brief Description of the Drawings

[0017] Figure 1 、 2 is the system schematic diagram of the present utility model.

[0018] Figure 1 、 2 The numbers and names of the components in are as follows.

[0019] High-vacuum desulfurization tank 1, liquid-proof non-condensable gas discharge device 2, liquid spraying device 3, liquid level measurement and control component 4, liquid pump 5, liquid level regulating valve 6, conventional vacuum pump 7, condensate circulation pump 8, liquid Na, high-concentration non-condensable gas S, remaining non-condensable gas S2, raw non-condensable gas S0, discharged non-condensable gas Sn, raw condensate water W1, condensate external drainage W2, reaction external drainage P. Detailed Embodiment

[0020] Figure 1 、 2 are the system schematic diagram and embodiments of the present utility model.

[0021] The specific embodiment 1 of the present utility model is as follows. Refer to Figure 1 as shown. A vacuum pumping device for non-condensable gas in the flash condensate of desulfurization slurry based on the absorption method is composed of a high-vacuum desulfurization tank 1, a conventional vacuum pump 7, and other connecting pipelines and components. It is characterized in that a liquid spraying device 3, a liquid-proof non-condensable gas discharging device 2, a liquid level measuring and controlling component 4, a spraying reaction zone for enriching high-concentration non-condensable gas S1, a gas collecting zone for enriching remaining non-condensable gas S2, and a bottom liquid storage zone are arranged inside the high-vacuum desulfurization tank 1. Among them, the non-condensable gas inlet of the spraying reaction zone for enriching high-concentration non-condensable gas S1 is communicated with the gas transmission pipe of the raw non-condensable gas S0; the air outlet of the liquid-proof non-condensable gas discharging device 2 is connected to the inlet of the conventional vacuum pump 7, and the outlet of the conventional vacuum pump 7 is communicated with the exhaust pipe for discharging non-condensable gas Sn; the feed inlet of the liquid spraying device 3 is connected to the outlet of the liquid pump 5, and the inlet of the liquid pump 5 is communicated with the liquid transmission pipe of the liquid Na; the liquid level probe of the liquid level measuring and controlling component 4 is arranged below the liquid level of the bottom liquid storage zone, and the bottom liquid outlet of the bottom liquid storage zone is connected to the inlet of the liquid level regulating valve 6.

[0022] The air inlet for the raw non-condensable gas S0 to enter the high-vacuum desulfurization tank 1 is arranged in the lower area of the liquid spraying device 3. The lower part of the liquid spraying device 3 is the spraying reaction zone for enriching high-concentration non-condensable gas S1, and the upper part is the gas collecting zone for enriching the remaining non-condensable gas S2. The liquid-proof non-condensable gas discharging device 2 is arranged on the upper part of the liquid spraying device 3. The inlet of the liquid pump 5 is also connected to the inlet of the liquid level regulating valve 6, and the outlet of the liquid level regulating valve 6 is communicated with the drain pipe of the reaction external drainage P.

[0023] The conventional vacuum pump 7 adopts a water-ring vacuum pump, a water jet air ejector or a roots vacuum pump structure.

[0024] The liquid spraying device 3 and its lower area adopt a nozzle-type empty tower structure or a packing structure.

[0025] The liquid Na adopts a sodium hydroxide solution with a mass concentration range of 0% to 60% or other reactive agents.

[0026] The specific embodiment 2 of the present utility model is as follows. Refer to Figure 2As shown in the figure. A vacuum pumping device for non-condensable gas in the flash condensate of desulfurization slurry based on the absorption method, which consists of a high-vacuum desulfurization tank 1, a conventional vacuum pump 7 and other connecting pipelines and components. It is characterized in that a liquid spraying device 3, a liquid-proof non-condensable gas discharging device 2, a liquid level measurement and control assembly 4, a spraying reaction zone enriched with high-concentration non-condensable gas S1, a gas collection zone enriched with remaining non-condensable gas S2 and a bottom liquid storage zone are arranged inside the high-vacuum desulfurization tank 1. The non-condensable gas inlet of the spraying reaction zone enriched with high-concentration non-condensable gas S1 is communicated with the gas transmission pipe of the raw non-condensable gas S0. The gas outlet of the liquid-proof non-condensable gas discharging device 2 is connected with the inlet of the conventional vacuum pump 7, and the outlet of the conventional vacuum pump 7 is communicated with the exhaust pipe for discharging non-condensable gas Sn. The feed inlet of the liquid spraying device 3 is connected with the outlet of the liquid pump 5, and the inlet of the liquid pump 5 is communicated with the liquid transmission pipe of the liquid Na. The liquid level probe of the liquid level measurement and control assembly 4 is arranged below the liquid level of the bottom liquid storage zone, and the bottom liquid outlet of the bottom liquid storage zone is connected with the inlet of the liquid level regulating valve 6.

[0027] When the raw non-condensable gas S0 is arranged at the top of the high-vacuum desulfurization tank 1, or when the inlet for the raw condensate water W1 mixed with the raw non-condensable gas to enter the high-vacuum desulfurization tank 1 is arranged at the top of the high-vacuum desulfurization tank 1, the top space inside the high-vacuum desulfurization tank 1 is the gas collection zone for the raw non-condensable gas S0, the lower part thereof is the liquid spraying device 3, the lower part of the liquid spraying device 3 is the spraying reaction zone enriched with high-concentration non-condensable gas S1, further down is the liquid-proof non-condensable gas discharging device 2, further down is the gas collection zone enriched with remaining non-condensable gas S2, and further down is the bottom liquid storage zone. The outlet of the liquid pump 5 is also connected with the outlet of the condensate water circulation pump 8. The inlet of the condensate water circulation pump 8 is respectively connected with the bottom liquid outlet of the bottom liquid storage zone and the inlet of the liquid level regulating valve 6, and the outlet of the liquid level regulating valve 6 is communicated with the drain pipe for the condensate external drainage W2.

[0028] The conventional vacuum pump 7 adopts a water-ring vacuum pump, a water jet air ejector or a roots vacuum pump structure.

[0029] The liquid spraying device 3 and its lower area adopt a nozzle-type empty tower structure or a packing structure.

[0030] The liquid Na adopts a sodium hydroxide solution with a mass concentration range of 0% to 60% or other reactive agents.

[0031] It should be noted that based on the key technologies of secondary desulfurization or removal of other components from multi-component non-condensable gases to significantly reduce the total amount of remaining non-condensable gases, the present utility model proposes a complete set of key vacuum pumping components for deep flue gas waste heat recovery by flash evaporation of desulfurization slurry. According to this solution, there can be different specific implementation measures and specific implementation devices with different structures. The above specific implementation manners are only some of the implementation forms. Any other similar simple deformed implementation manners, such as simple addition or subtraction, deformation, and change of relative position of internal components and interfaces, simple combination and adjustment of external pipelines and components, or simple change of the vacuum pumping method, etc., all fall within the protection scope of the present utility model.

Claims

1. A desulfurization slurry flash condensation non-condensable gas vacuum pump based on absorption method, comprising a high vacuum desulfurization tank (1), a conventional vacuum pump (7) and other connecting pipes and components, characterized in that: The high vacuum desulfurization tank (1) is provided with a liquid spraying device (3), a liquid-proof non-condensable gas discharge device (2), a liquid level measurement and control component (4), a spray reaction zone where high-concentration non-condensable gas (S1) is enriched, a gas collection zone where residual non-condensable gas (S2) is enriched, and a bottom liquid storage zone, wherein the non-condensable gas inlet of the spray reaction zone where high-concentration non-condensable gas (S1) is enriched is connected to the gas transmission pipe of the original non-condensable gas (S0); the liquid-proof non-condensable gas discharge device (2) The gas outlet is connected to the inlet of a conventional vacuum pump (7), and the outlet of the conventional vacuum pump (7) is connected to an exhaust pipe for discharging non-condensable gas (Sn); the feed inlet of the liquid spraying device (3) is connected to the outlet of the liquid pump (5), and the inlet of the liquid pump (5) is connected to a liquid infusion pipe of the liquid (Na); the liquid level probe of the liquid level measurement and control component (4) is arranged below the liquid surface of the bottom liquid storage area, and the bottom liquid outlet of the bottom liquid storage area is connected to the inlet of the liquid level regulating valve (6).

2. A desulfurization slurry flash condensation and non-condensable gas vacuum pumping device based on absorption method as claimed in claim 1, characterized in that When the air inlet of the original non-condensable gas (S0) entering the high vacuum desulfurization tank (1) is arranged in the lower area of ​​the liquid spraying device (3), the lower part of the liquid spraying device (3) is a spraying reaction zone where the high concentration non-condensable gas (S1) is enriched, and the upper part is a gas collection zone where the remaining non-condensable gas (S2) is enriched. The liquid-proof non-condensable gas discharge device (2) is arranged on the upper part of the liquid spraying device (3), and the inlet of the liquid pump (5) is also connected to the inlet of the liquid level regulating valve (6), and the outlet of the liquid level regulating valve (6) is connected to the drainage pipe of the reaction external drainage (P).

3. A desulfurization slurry flash condensation and non-condensable gas vacuum pumping device based on absorption method as claimed in claim 1, characterized in that When the native non-condensable gas (S0) is arranged at the top of the high vacuum desulfurization tank (1), or when the inlet for the native condensate (W1) mixed with the native non-condensable gas to enter the high vacuum desulfurization tank (1) is arranged at the top of the high vacuum desulfurization tank (1), the top space in the high vacuum desulfurization tank (1) is the gas collection area of ​​the native non-condensable gas (S0), and the lower part thereof is the feed liquid spraying device (3), and the lower part of the feed liquid spraying device (3) is the high concentration non-condensable gas (S1) rich gas area. The outlet of the liquid pump (5) is also connected to the outlet of the condensate circulation pump (8), and the inlet of the condensate circulation pump (8) is respectively connected to the bottom liquid outlet of the bottom liquid storage area and the inlet of the liquid level regulating valve (6), and the outlet of the liquid level regulating valve (6) is connected to the drainage pipe of the condensate external drainage (W2).

4. A desulfurization slurry flash condensation and non-condensable gas vacuum pumping device based on absorption method as claimed in claim 1, characterized in that The conventional vacuum pump (7) adopts a water ring vacuum pump, a water jet steam extractor or a Roots vacuum pump structure.

5. A desulfurization slurry flash condensation and non-condensable gas vacuum pumping device based on absorption method as claimed in claim 1, characterized in that The liquid spraying device (3) and the lower region thereof adopt a nozzle-type empty tower structure or a packing structure.

6. A desulfurization slurry flash condensation and non-condensable gas vacuum pumping device based on absorption method as claimed in claim 1, characterized in that The feed liquid (Na) is a sodium hydroxide solution or other reactive reagent with a mass concentration ranging from 0% to 60%.

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