Waste heat recycling method of pressurizing tower

Abstract

The invention discloses a waste heat recycling method of a pressurizing tower, and belongs to the technical field of energy conservation and environmental protection. The method comprises the following steps: (1) taking a gas phase at the top of a recovery tower as a heat source to enter a pressurizing tower reboiler for heat exchange treatment; and (2) taking the gas phase at the top of the pressurized tower as a heat source to enter a reboiler of the atmospheric tower for heat exchange treatment. According to the waste heat recycling method of the pressurizing tower, the waste heat of the gas phase at the top of the tower is recycled to replace part of 1.0 MPa steam for heating, so that the energy consumption is reduced, and the heat efficiency is improved; the method is convenient and fast to transform the existing pressurizing tower, is easy to implement, and has wide application prospects.

Description

Technical Field

[0001] The invention relates to the field of energy conservation and environmental protection, and in particular to a method for recovering and utilizing waste heat of a pressurized tower. Background Art

[0002] A pressurized tower is a chemical equipment, mainly used for mass and heat transfer between gas and liquid or liquid and liquid in industrial production. It uses internal components to make full contact between different phases, thereby achieving separation and purification of substances. Pressurized towers are widely used in chemical, petroleum, biological, pharmaceutical and other industries.

[0003] The temperature of the kettle of the pressure tower is 138℃, the pressure is 0.81Mpa, the temperature of the top of the tower is 136.2℃, and the pressure of the top of the tower is 0.80Mpa. The top and kettle of the pressure tower are connected to the pressure tower reboiler and the atmospheric tower reboiler respectively. The pressure tower reboiler receives 1.0MPa steam to heat the liquid in the kettle. The steam condenses into condensate and enters the pre-tower reboiler. The pre-tower reboiler further exchanges heat on the condensate, and the condensate flows back to the condensate pipe network. The gas phase at the top of the pressure tower enters the atmospheric tower reboiler to exchange heat with the liquid in the atmospheric tower. The gas phase after heat exchange is cooled into liquid phase by the circulating water cooler. The cooled liquid phase enters the reflux tank and flows back to the pressure tower to complete the cycle.

[0004] At present, the heat source of the pressurized tower kettle only comes from 1.0MPa steam, which consumes a lot of energy. In order to further reduce energy consumption and improve thermal efficiency, the pressurized tower can be further modified. Summary of the invention

[0005] The purpose of the present invention is to provide a method for recovering waste heat from a pressurized tower, which recovers waste heat from the gas phase at the top of the tower to replace part of the 1.0 MPa steam heating, thereby reducing energy consumption and improving heat utilization efficiency.

[0006] To achieve the above object, the present invention provides a method for recovering waste heat from a pressurized tower, comprising: (1) The gas phase at the top of the recovery tower is used as a heat source to enter the reboiler of the pressure tower for heat exchange treatment; (2) The gas phase at the top of the pressure tower is used as the heat source to enter the reboiler of the atmospheric tower for heat exchange treatment.

[0007] Preferably, two pressure tower reboilers are provided, and the two pressure tower reboilers are respectively connected to a pressure tower reboiler return gas inlet pipeline, and the pressure tower reboiler return gas inlet is symmetrically arranged on one side of the pressure tower kettle collecting tank.

[0008] Preferably, after the recovery tower top gas phase completes heat exchange in the pressure tower reboiler, the recovery tower condensate is obtained, and the recovery tower condensate is sent to the cooler for heat exchange with the tower bottom liquid from the pressure tower bottom liquid collecting tank. After the heat exchange, the recovery tower condensate enters the recovery tower reflux tank, and the tower bottom liquid returns to the pressure tower reboiler and then returns to the pressure tower bottom.

[0009] Preferably, a nitrogen inlet for the bottom of the pressure tower is arranged on one side of the return gas inlet of the reboiler of the pressure tower.

[0010] Preferably, a gas outlet baffle is welded at the gas outlet at the top of the pressure tower, and the gas flow rate is controlled by the gas outlet baffle and the gas forms a vortex in the pipeline, thereby improving the heat exchange efficiency of the gas phase at the top of the pressure tower after entering the reboiler of the atmospheric pressure tower.

[0011] The gas outlet baffle comprises a spliced ​​circular chassis with a plurality of through holes evenly distributed on the chassis. The chassis is welded to the top of the pressure tower by angle steel; the angle steel is set at an angle of 3 to 5 degrees with the vertical direction.

[0012] Preferably, the bottom liquid collecting box comprises a first liquid collecting tank and a second liquid collecting tank for collecting the bottom liquid, liquid outlet pipes are symmetrically arranged on both sides of the second liquid collecting tank, and supporting ribs are arranged below the liquid outlet pipes.

[0013] Therefore, the waste heat recovery and utilization method of a pressurized tower of the present invention has the following beneficial effects: (1) Weld a gas outlet baffle at the gas outlet at the top of the recovery tower. By adjusting the angle of the baffle, the gas forms a vortex in the pipeline, thereby optimizing the gas flow and improving the heat exchange efficiency; (2) The return gas inlet of the pressure tower reboiler is set below the tower kettle collecting tank and connected to the pressure tower reboiler. A return gas inlet is added on its symmetrical side to improve the utilization rate of the gas phase; (3) The gas phase at the top of the recovery tower is used as the heat source to enter the reboiler of the pressurized tower for heat exchange. The 1.0MPa steam consumption is reduced by 20t / h before and after the transformation.

[0014] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0016] Figure 1 This is a schematic diagram of the top structure of the pressure tower; Figure 2is a top view of the gas outlet baffle; Figure 3 It is a schematic diagram of the tower kettle liquid collecting box and its surrounding structures; Reference numerals: 1. Gas outlet baffle; 101. Chassis; 102. Angle steel; 2. Tower bottom liquid collecting tank; 201. First liquid collecting tank; 202. Second liquid collecting tank; 203. Liquid outlet pipe; 204. Support ribs; 3. Pressurized tower reboiler return gas inlet; 4. Tower bottom nitrogen inlet. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0018] In order to make the purpose, technical scheme and advantages of the present application clearer, more thorough and more complete, the technical scheme of the present invention is clearly and completely described below through the accompanying drawings and examples. The following detailed descriptions are all descriptions of the embodiments, and are intended to provide further detailed descriptions of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present application belongs.

[0019] Embodiment 1 A method for recovering waste heat from a pressurized tower, comprising: (1) The gas phase at the top of the pressure tower is used as a heat source to enter the atmospheric tower reboiler for heat exchange treatment. A gas outlet baffle 1 is welded at the gas outlet at the top of the pressure tower, such as Figure 1 As shown; the top view of the gas outlet baffle 1 is as shown Figure 2 shown.

[0020] The gas outlet baffle 1 comprises a circular chassis 101, on which a plurality of through holes are evenly distributed, which are not shown in the figure. The chassis 101 is welded to the top of the pressure tower by angle steel 102. When the angle steel 102 is welded, an angle of 3 to 5 degrees is set with the vertical direction.

[0021] The gas outlet baffle 1 can control the gas flow rate to ensure that the gas flow rate is within a suitable range, which can not only meet production needs, but also ensure the safe and stable operation of the pipeline and its surrounding environment. At the same time, by adjusting the angle of the angle steel 102 during welding, the gas can form a vortex in the pipeline, thereby optimizing the gas flow and improving the heat exchange efficiency of the subsequent process.

[0022] (2) The top gas phase of the recovery tower is used as a heat source to replace the original 1.0Mpa steam and enter the reboiler of the pressurized tower for heat exchange treatment.

[0023] like Figure 3 The figure shows the tower bottom liquid collecting box and its surrounding structures.

[0024] The bottom liquid collecting box 2 includes a first liquid collecting tank 201 and a second liquid collecting tank 202 for collecting the bottom liquid. The second liquid collecting tank 202 is formed by cutting off the original liquid sealing plate below the first liquid collecting tank 201 and then welding. Liquid outlet pipes 203 are symmetrically arranged on both sides of the second liquid collecting tank 202, and support ribs 204 are arranged below the liquid outlet pipes 203.

[0025] The return gas inlet 3 of the pressure tower reboiler is arranged below the tower kettle collecting tank 2 and is connected to the pressure tower reboiler. The position of the return gas inlet 3 of the pressure tower reboiler is the original position of the pressure tower, except that a return gas inlet 3 of the pressure tower reboiler is added on its symmetrical side. The two return gas inlets 3 of the pressure tower reboiler are respectively connected to one pressure tower reboiler. The pressure tower reboiler is a prior art. Figure 3 Not shown.

[0026] The top gas phase (161°C) of the recovery tower enters two pressurized tower reboilers for heat exchange. The recovery tower condensate obtained after the heat exchange is transported to the same cooler and heat exchanged with the bottom liquid (101.3°C) from the pressurized tower bottom liquid collecting tank 2. After the heat exchange, the recovery tower condensate (118°C) enters the recovery tower reflux tank, and the bottom liquid returns to the pressurized tower reboiler and then to the pressurized tower bottom. At the same time, the cooler can cool the unliquefied top gas phase of the recovery tower carried by the recovery tower condensate.

[0027] A nitrogen inlet 4 for the bottom of the tower is arranged on one side of the return gas inlet 3 of the pressurized tower reboiler. The nitrogen plays a role of displacement protection. The position of the nitrogen inlet 4 for the bottom of the tower can meet the requirements of material inlet and outlet, and can be arranged according to actual needs.

[0028] The original process of the pressure tower used 75t / h of 1.0Mpa steam. After the transformation, the top gas phase of the recovery tower was used as the heat source of the pressure tower kettle to completely replace the 1.0Mpa steam. The 1.0Mpa steam was directly used as the heat source of the recovery tower with a consumption of 55t / h. The consumption of 1.0MPa steam was reduced by 20t / h before and after the transformation.

[0029] Therefore, the waste heat recovery and utilization method of a pressurized tower of the present invention recovers the waste heat of the gas phase at the top of the tower to replace part of the 1.0MPa steam heating, thereby reducing energy consumption and improving thermal efficiency; this method is convenient and fast for the transformation of the existing pressurized tower, is easy to implement, and has broad application prospects.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for recovering waste heat from a pressurized tower, characterized in that: include: (1) The gas phase at the top of the recovery tower is used as a heat source to enter the reboiler of the pressure tower for heat exchange treatment; (2) The gas phase at the top of the pressure tower is used as the heat source to enter the reboiler of the atmospheric tower for heat exchange treatment.

2. The method for recovering waste heat from a pressurized tower according to claim 1, characterized in that: Two pressure tower reboilers are provided, and the two pressure tower reboilers are respectively connected to a pressure tower reboiler return gas inlet pipeline, and the pressure tower reboiler return gas inlet is symmetrically arranged on one side of the pressure tower kettle collecting tank.

3. The method for recovering waste heat from a pressurized tower according to claim 2, characterized in that: After the heat exchange of the top gas phase of the recovery tower is completed in the reboiler of the pressure tower, the recovery tower condensate is obtained. The recovery tower condensate is sent to the cooler for heat exchange with the bottom liquid from the bottom liquid collecting tank of the pressure tower. After the heat exchange, the recovery tower condensate enters the reflux tank of the recovery tower, and the bottom liquid returns to the reboiler of the pressure tower and then returns to the bottom of the pressure tower.

4. The method for recovering waste heat from a pressurized tower according to claim 2, characterized in that: A nitrogen inlet for the kettle is arranged on the side of the return gas inlet of the pressure tower reboiler.

5. The method for recovering waste heat from a pressurized tower according to claim 1, characterized in that: A gas outlet baffle is welded at the gas outlet of the top of the pressure tower. The gas flow rate is controlled by the gas outlet baffle and the gas forms a vortex in the pipeline, thereby improving the heat exchange efficiency of the gas phase at the top of the pressure tower after entering the reboiler of the atmospheric pressure tower.

6. The method for recovering waste heat from a pressurized tower according to claim 5, characterized in that: The gas outlet baffle comprises a spliced ​​circular chassis with a plurality of through holes evenly distributed on the chassis. The chassis is welded to the top of the pressure tower by angle steel; the angle steel is set at an angle of 3 to 5 degrees with the vertical direction.

7. The method for recovering waste heat from a pressurized tower according to claim 2, characterized in that: The tower bottom liquid collecting box comprises a first liquid collecting tank and a second liquid collecting tank for collecting the tower bottom liquid. Liquid outlet pipes are symmetrically arranged on both sides of the second liquid collecting tank, and supporting ribs are arranged below the liquid outlet pipes.

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