Wet air cooler device for propane dehydrogenation to propylene device

Abstract

The utility model provides a kind of wet air cooler device for propane dehydrogenation preparation propylene device, the device includes air cooler body, spraying device, water collecting device, circulating pump and water replenishing device, spraying device is set in air cooler body, and it is located above heat exchange pipe, for circulating water is sprayed to heat exchange pipe;Water collecting device is set below air cooler body, for collecting the water that flows from air cooler body;Water collecting device and spraying device are communicated by spraying main pipe, circulating pump is set on spraying main pipe, for water in water collecting device is transported to spraying device;Water replenishing device is connected with water collecting device, for when the water level in water collecting device drops, water is supplemented to water collecting device to maintain preset water level.Spraying device sprays circulating water to heat exchange pipe, using the latent heat of vaporization of water can take away heat, enhances the heat exchange efficiency of air cooler, effectively solves the problem of insufficient cooling capacity in prior art dry air cooler due to high ambient temperature.

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment technology, and in particular to a wet air cooler device for a propane dehydrogenation to propylene production unit. Background Technology

[0002] In propane dehydrogenation to propylene production units, distillation columns are typically used to separate the product propylene from the feedstock propane. The vaporous material at the top of the column needs to be condensed by an air cooler to achieve separation. Currently, the air coolers commonly used in these units are mostly dry-type finned tube air coolers, whose heat exchange capacity is directly related to the ambient air temperature.

[0003] A dry finned tube air cooler includes a fan and heat exchange tubes. The fan drives airflow through the gaps between the heat exchange tubes to achieve cooling.

[0004] The applicant has discovered that the existing technology has at least the following technical problems: In high-temperature weather conditions such as summer, the cooling capacity of the dry air cooler will decrease significantly due to the excessively high ambient temperature, failing to provide sufficient cooling for the distillation process. This forces the distillation column to operate at higher pressures, which not only affects the purity of the final product propylene but may also cause the pressure inside the column to exceed the set value of the safety valve, triggering the safety valve to trip, thus posing a serious threat to the stable and safe operation of the entire unit. Utility Model Content

[0005] The purpose of this utility model is to provide a wet air cooler device for a propane dehydrogenation to propylene production unit, so as to solve the technical problem that the cooling capacity of dry air coolers is significantly reduced when the ambient temperature is too high in hot weather. The various technical effects of the preferred technical solutions provided by this utility model are described in detail below.

[0006] To achieve the above objectives, the present invention provides the following technical solution: The wet air cooler device for a propane dehydrogenation to propylene unit provided by this utility model includes an air cooler body, a spray device, a water collection device, a circulating pump, and a water replenishment device, wherein: The spraying device is installed inside the air cooler body and located above the heat exchange tubes, and is used to spray circulating water onto the heat exchange tubes. The water collection device is located below the air cooler body and is used to collect water flowing down from the air cooler body; The water collection device and the spraying device are connected by a spraying main pipe. The circulating pump is installed on the spraying main pipe and is used to transport water from the water collection device to the spraying device. The water replenishment device is connected to the water collection device and is used to replenish water to the water collection device to maintain a preset water level when the water level in the water collection device drops.

[0007] Preferably, the spray area of ​​the spray device completely covers the horizontal cross-section of all the heat exchange tubes.

[0008] Preferably, the spraying device includes a spiral nozzle and branch pipes, wherein: The branch pipe is connected to the main spray pipe. A control valve is installed on the branch pipe. The spiral nozzle is connected to the branch pipe. When the control valve is opened, cold water is sprayed out by the spiral nozzle on the branch pipe.

[0009] Preferably, there are two or more branch pipes, and on each branch pipe there are two or more spiral nozzles, with the same spiral nozzles arranged at intervals in the horizontal direction.

[0010] Preferably, a filter is also provided on the main spray pipe, and the filter is located in the pipe section between the circulating pump and the water collection device.

[0011] Preferably, the main spray pipe has a water absorption section, which extends into the bottom of the inner cavity of the water collection device in a sealed manner, and the water absorption section is in the shape of a downward-sloping funnel.

[0012] Preferably, the cold water in the water collection device is desalinated water.

[0013] Preferably, there are two air cooler bodies connected in series on the spray main pipe, and the number of spray devices corresponds one-to-one with the number of air cooler bodies.

[0014] Preferably, the water replenishment device includes a water replenishment pipeline connected to a water source, and a float level switch installed in the water collection device for sensing the water level and controlling the opening and closing of the water replenishment pipeline.

[0015] Preferably, the water collection device includes a water storage tank, and a level gauge is installed on the side wall of the water storage tank to visually display the current water level in the water storage tank; A pressure gauge is installed on the main spray pipe to monitor the spray pressure in real time.

[0016] The wet air cooler device for a propane dehydrogenation to propylene unit provided by this utility model has the following advantages compared with the prior art: By adding a spray device inside the air cooler body, convective heat transfer is combined with evaporative cooling of water. The spray device sprays circulating water onto the heat exchange tubes inside the air cooler body. Utilizing the latent heat of vaporization of water, a large amount of heat can be removed, greatly enhancing the overall heat exchange efficiency of the air cooler and effectively solving the problem of insufficient cooling capacity caused by excessively high ambient temperatures in existing dry air coolers. By setting up a water replenishment device, water lost through evaporation can be automatically replenished, ensuring a stable water volume in the circulation system. This avoids the risk of damage to the circulation drive device due to water shortage, reduces manual maintenance costs, and further improves the long-term reliability of the entire unit. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of a wet air cooler unit used in a propane dehydrogenation to propylene production plant. Figure 2 This is a schematic diagram of the cooperation structure between the spray device and the heat exchange tubes inside the air cooler.

[0019] In the diagram: 1. Air cooler body; 11. Heat exchange tube; 12. Fan; 2. Spray device; 21. Spiral nozzle; 22. Branch pipe; 23. Control valve; 3. Water storage tank; 4. Circulating pump; 5. Filter; 6. Main inlet pipe; 61. Suction section; 7. Float level switch; 8. Level gauge; 9. Pressure gauge. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0021] In the description of this utility model, it should be understood that the terms "center," "length," "width," "height," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and "side," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0022] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] This utility model provides a wet air cooler device for a propane dehydrogenation to propylene unit. In the propane dehydrogenation process, the gaseous material from the top of the propane distillation column, etc., mainly consists of propylene and unreacted propane, and needs to be fully condensed and cooled before entering subsequent processes. Addressing the problem of insufficient cooling capacity of traditional dry air coolers in high ambient temperatures such as summer, the device provided in this embodiment effectively solves this problem, thereby ensuring the stable, safe, and efficient operation of the production unit.

[0024] The following is combined with Figure 1 and Figure 2 The technical solution provided by this utility model will be described in more detail.

[0025] like Figure 1 and Figure 2As shown, the wet air cooler device for a propane dehydrogenation to propylene unit provided by this utility model includes an air cooler body 1, a spray device 2, a water collection device (in this embodiment, the water collection device is a water storage tank 3), a circulating pump 4, and a water replenishment device. The spray device 2 is located inside the air cooler body 1 and above the heat exchange tubes 11, used to spray circulating water onto the heat exchange tubes 11. The water collection device is located below the air cooler body 1, used to collect water flowing down from the air cooler body 1. The water collection device and the spray device 2 are connected via a spray manifold, and the circulating pump 4 is located on the spray manifold, used to transport water from the water collection device to the spray device 2. The water replenishment device is connected to the water collection device, used to replenish water to the water collection device to maintain a preset water level when the water level in the water collection device drops.

[0026] The air cooler body 1 is the main site for heat exchange. The air cooler body 1 can adopt an A-type or V-type structure commonly used in the chemical industry. Its frame is usually made of materials such as carbon steel or stainless steel to provide sufficient structural strength and corrosion resistance. The interior of the air cooler body 1 is densely packed with heat exchange tubes 11 for flowing through the process materials to be cooled. The heat exchange tubes 11 are typically finned tubes, meaning that a large number of fins are added to the outer surface of the base tube to significantly increase the contact area with external air and water, thereby enhancing the heat exchange effect.

[0027] See Figure 2 As shown, a large axial fan 12 is usually provided above the air cooler body 1 to force air to flow through the heat exchange tube bundle 11 to remove heat.

[0028] The spray device 2 is located inside the air cooler body 1 and is positioned above the entire heat exchange tube bundle 11, used to evenly distribute the circulating water to the outer surface of the heat exchange tubes 11. See also Figure 1 and Figure 2 As shown, the spray device 2 includes a spiral nozzle 21 and a branch pipe 22, wherein: the branch pipe 22 is connected to the main spray pipe, a control valve 23 is provided on the branch pipe 22, the spiral nozzle 21 is connected to the branch pipe 22, and when the control valve 23 is opened, cold water is sprayed out from the spiral nozzle 21 on the corresponding branch pipe 22.

[0029] The branch pipes 22 are arranged in parallel, and their spacing is calculated to ensure that the spray device 2 can cover the horizontal cross-section of all heat exchange tubes 11 in the entire air cooler body 1. On each branch pipe 22, multiple spiral nozzles 21 are evenly installed along its length.

[0030] The spiral nozzle 21 is an existing, mature device. In the prior art, the spiral nozzle 21 is a nozzle capable of producing solid cone or hollow cone spray patterns. Its structure is not easily clogged, and it can atomize water flow into fine water droplets and spray them at a specific angle. By reasonably selecting the model, spray angle, and installation spacing of the spiral nozzle 21, the spray area of ​​the entire spray device 2 can be designed to completely cover the horizontal cross-section of all heat exchange tubes 11, ensuring that there are no dead zones in heat exchange.

[0031] See Figure 1 As shown, a control valve 23 is installed on each branch pipe 22 for easy adjustment and maintenance. By adjusting the opening of each control valve 23, the spray water volume of each branch pipe can be precisely controlled, thereby optimizing the uniformity of the water film distribution on the surface of the entire heat exchange tube bundle 11, or shutting off the spray in the corresponding area when some heat exchange tube bundles 11 need maintenance.

[0032] See Figure 1 As shown, a water collection device is located below the air cooler body 1 to collect water that flows down from the outer surface of the heat exchange tube 11 but is not evaporated, so that it can be recycled.

[0033] In this embodiment, the water collection device can be a reinforced concrete water storage tank 3 or a large metal (such as carbon steel or stainless steel) water collection tray. Its horizontal projected area should be greater than or equal to the horizontal projected area of ​​the air cooler body 1 to ensure that all dripping water can be effectively collected.

[0034] To facilitate on-site monitoring of water levels by operators, a glass tube level gauge 8 or a magnetic float level gauge 8, etc., can be installed on the side wall of the water collection device for intuitive display of water levels.

[0035] The main inlet pipe 6 is used to connect the water collection device and the spray device 2 to form a hydraulic conveying system. In this embodiment, see... Figure 1 The circulating pump 4 is used to provide the necessary power for the circulating flow of water.

[0036] See Figure 1 As shown, a filter 5 is installed in the inlet pipe section of the circulating pump 4, that is, on the pipe from which water is drawn out from the water collection device. The function of the filter 5 is to filter out solid impurities that may be contained in the circulating water, such as dust, scale, etc., to prevent impurities from entering and clogging the spiral nozzles 21 of the spray device 2, thereby ensuring the long-term stability of the spraying effect and protecting the circulating pump 4 from wear.

[0037] The filter 5 mentioned above can be a basket filter 5 or a Y-type filter 5, and the filter screen should be cleaned or replaced regularly.

[0038] To monitor the operating status of the cyclic system, see [link / reference]. Figure 1As shown, a pressure gauge 9 is installed on the outlet pipe of the circulating pump 4 (e.g., on the main inlet pipe 6) to determine whether the system is operating normally by observing the pressure reading. For example, too low pressure may indicate a pump malfunction or pipe leak, while too high pressure may indicate a clogged filter 5 or nozzle.

[0039] The water replenishment device is connected to the water collection device (in this embodiment, the water storage tank 3) and is used to automatically replenish the water volume when the circulating water decreases due to evaporation, thereby maintaining the water level in the water collection device (in this embodiment, the water storage tank 3) within a preset reasonable range.

[0040] In this embodiment, see Figure 1 As shown, the water supply device includes a water supply pipeline and a float level switch 7 installed inside the water collection device (water storage tank 3). One end of the water supply pipeline is connected to a reliable external water source, and the other end is connected to the water collection device. It should be noted that, in order to slow down the scaling rate on the surface of the heat exchange tube 11 and extend the service life of the equipment, the water source is preferably demineralized water or softened water.

[0041] The float level switch 7 includes a float that moves up and down with the water level and a mechanical valve linked to the float, which is installed on the water supply pipeline. The float level switch 7 is a mature device in the prior art. Its working mechanism is as follows: when the water level in the water collection device (storage tank 3) drops to a preset lower limit level due to evaporation, the float descends accordingly, opening the valve on the water supply pipeline via a lever mechanism to begin replenishing water into the storage tank 3; as the water level rises, the float also rises accordingly. When the water level reaches a preset upper limit level, the float closes the valve via the lever mechanism, stopping water replenishment. In this way, the water level is automatically maintained between the upper and lower limits, ensuring that the circulating pump 4 always has sufficient water to draw in, avoiding dry running and damage due to water shortage, thus greatly reducing the need for manual intervention.

[0042] To prevent vortices from forming at the suction inlet of the circulating pump 4, as an optional implementation, see [link to implementation details]. Figure 1 As shown, the main spray pipe has a water suction section 61, which extends into the bottom of the inner cavity of the water collection device in a sealed manner, and the water suction section 61 is a flared shape with an inclined downward direction.

[0043] The wet air cooler device provided in this embodiment operates as follows when used for material cooling in a propane dehydrogenation unit: High-temperature gaseous process material from the top of the propane distillation column is first introduced into the heat exchange tubes 11 within the air cooler body 1. Subsequently, the circulation pump 4 and the air cooler fan 12 are started. The circulation pump 4, after filtering the circulating water from the water collection device (water storage tank 3) through the filter 5, pressurizes and delivers it to the spray device 2 located above the heat exchange tubes 11. The water flows through the branch pipes 22 and is finally sprayed from numerous spiral nozzles 21, forming a uniform water mist that completely covers the outer surface and fins of the hot heat exchange tubes 11. When the water comes into contact with the high-temperature tube wall, some heat is transferred to the water through convection, raising its temperature. However, the more significant heat transfer occurs when the water absorbs a large amount of heat and undergoes a phase change, evaporating into water vapor. Due to the enormous latent heat of vaporization of water, this process can extremely efficiently remove heat from the heat exchange tubes 11. Meanwhile, the fan 12 forces a large amount of ambient air to flow through the tube bundle. On the one hand, the air itself loses some heat through convection heat exchange; on the other hand, the flowing air can quickly carry away the humid and hot air filled with water vapor near the surface of the heat exchange tube 11, reducing the water vapor partial pressure between the tubes, thereby greatly promoting water evaporation and further enhancing the cooling effect. Through this composite heat exchange method combining air convection and water evaporation cooling, the process materials inside the tubes can be rapidly and deeply cooled and condensed.

[0044] During this process, the unevaporated water drips down along the fins and walls of the heat exchange tube 11 and is eventually collected by the water collection device (water storage tank 3) located below the air cooler body 1. The water collected in the water collection device (water storage tank 3) is then drawn back into the circulating pump 4 through the main water inlet pipe 6, repeating the above-mentioned filtration, pressurization, and spraying process, thereby realizing the recycling of cooling water and saving water resources.

[0045] During the entire cooling cycle, the total water volume in the water collection device (water storage tank 3) continuously decreases due to water evaporation. At this time, the water replenishment device connected to the water collection device begins to function. When the water level drops to the preset lower limit, the float level switch 7 opens the water replenishment valve, replenishing the water collection device (water storage tank 3) with fresh water from an external demineralized water source; when the water level rises back to the preset upper limit, the valve closes. This structure ensures that the water volume of the circulation system remains stable at all times, thereby guaranteeing the long-term and reliable operation of the entire wet air cooler unit.

[0046] The specific features, structures, or characteristics described in this specification may be combined in any suitable manner in one or more embodiments or examples.

[0047] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0048] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A wet air cooler unit for a propane dehydrogenation to propylene plant, characterized in that, It includes the air cooler body, spray device, water collection device, circulating pump, and water makeup device, wherein: The spraying device is installed inside the air cooler body and located above the heat exchange tubes, and is used to spray circulating water onto the heat exchange tubes. The water collection device is located below the air cooler body and is used to collect water flowing down from the air cooler body; The water collection device and the spraying device are connected by a spraying main pipe. The circulating pump is installed on the spraying main pipe and is used to transport water from the water collection device to the spraying device. The water replenishment device is connected to the water collection device and is used to replenish water to the water collection device to maintain a preset water level when the water level in the water collection device drops.

2. The wet air cooler device for a propane dehydrogenation to propylene unit according to claim 1, characterized in that, The spray area of ​​the spray device completely covers the horizontal cross-section of all the heat exchange tubes.

3. The wet air cooler device for a propane dehydrogenation to propylene unit according to claim 1, characterized in that, The spraying device includes a spiral nozzle and branch pipes, wherein: The branch pipe is connected to the main spray pipe. A control valve is installed on the branch pipe. The spiral nozzle is connected to the branch pipe. When the control valve is opened, cold water is sprayed out by the spiral nozzle on the branch pipe.

4. The wet air cooler device for a propane dehydrogenation to propylene unit according to claim 3, characterized in that, The number of branch pipes is two or more, and the number of spiral nozzles on each branch pipe is two or more, with the spiral nozzles on the same pipe arranged at intervals in the horizontal direction.

5. The wet air cooler device for a propane dehydrogenation to propylene unit according to claim 1, characterized in that, A filter is also installed on the main spray pipe, and the filter is located in the pipe section between the circulating pump and the water collection device.

6. The wet air cooler device for a propane dehydrogenation to propylene unit according to claim 1, characterized in that, The main spray pipe has a water suction section, which extends into the bottom of the inner cavity of the water collection device in a sealed manner, and the water suction section is in the shape of a downward-sloping funnel.

7. The wet air cooler device for a propane dehydrogenation to propylene unit according to claim 1, characterized in that, The cold water in the water collection device is demineralized water.

8. The wet air cooler device for a propane dehydrogenation to propylene unit according to claim 1, characterized in that, Two air cooler bodies are connected in series on the main spray pipe, and the number of spray devices corresponds one-to-one with the number of air cooler bodies.

9. The wet air cooler device for a propane dehydrogenation to propylene unit according to claim 1, characterized in that, The water replenishment device includes a water replenishment pipeline connected to a water source, and a float level switch installed in the water collection device for sensing the water level and controlling the opening and closing of the water replenishment pipeline.

10. The wet air cooler device for a propane dehydrogenation to propylene unit according to claim 1, characterized in that, The water collection device includes a water storage tank, and a level gauge is installed on the side wall of the water storage tank to visually display the current water level in the water storage tank. A pressure gauge is installed on the main spray pipe to monitor the spray pressure in real time.

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