Do you know the layout requirements for common equipment in chemical plants?

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This post was last edited by Xin Ruifangxiao on 2023-2-16 at 15:13. Go to their homepage, add them as a friend, and then leave~ The production process in chemical plants relies on various types of equipment and pipelines; given the wide variety of such equipment and the unique characteristics of each one, there are specific rules and requirements that must be followed regarding their arrangement. A proper layout of equipment can improve production efficiency and ensure product quality, while also enhancing the efficiency of equipment maintenance and the safety of workers. Piping layout design is also an important component in chemical plants; it is directly related to the flow, reactions, and control of substances. Therefore, it must be carefully designed and installed to ensure the stability and safety of the production process. Here, we will provide a detailed explanation in three phases regarding the specific requirements for the layout of various chemical processing equipment. Let’s take a look together! 01 Layout of towers and specific requirements 1. Single-row layout: This is the most commonly used arrangement. When there are two or more towers or vertical containers on one side of the pipe gallery, their centerlines are usually aligned with each other. If two or more towers are equipped with a common platform, it is advisable to align their centerlines or their tangent lines ； 2. For towers with a smaller diameter but higher height, a multi-row arrangement can be used, either in two rows or in a triangular configuration; this allows the towers to be connected together using platforms, thereby enhancing their stability. However, sliding guide nodes should be used for the platform’s rooting components in order to accommodate the thermal expansion effects caused by different operating temperatures ； 3. For a framed layout, towers with a diameter of DN≤1000 mm can also be placed within the frame or on one side of it. Improve its stability using a framework, and install platforms and ladders. For segmented towers installed on a framework, when motorized lifting equipment cannot be used, maintenance lifting facilities should be provided on the framework. 02 Layout requirements for the tower and its associated equipment: The tower and its related equipment, such as feed heaters, reboilers that do not use open flames for heating, top condensers, reflux tanks, bottom extraction pumps, etc., should be arranged in sequence according to the process flow. If necessary, an independent operating system can be established within a specific area, which facilitates operation and management. 03 Determination of the distance between towers and vertical pipe fittings arranged along the pipe gallery and the pipe gallery itself 1. When pumps are installed between the tower and the pipe gallery, this distance should be determined based on the requirements related to the operation, maintenance, and piping of those pumps ； 2. When no pumps are installed between the tower and the pipe tray, the distance between the outer wall of the tower and the centerline of the pipe rack columns should not be less than 3 m. 04 Determination of the distance between towers and adjacent equipment: The distance between towers or between a tower and other adjacent equipment must not only meet the requirements for the layout and installation of pipelines, platforms, instruments, and small equipment, but also satisfy the needs related to operation, maintenance access, and foundation layout. The clear distance between the two towers should not be less than 2.5 m. 05 The installation height of towers and vertical vessels shall meet the following requirements: 1. When using internal pressure or the weight of fluids to convey materials to other equipment or pipelines, it shall be determined by the internal pressure as well as the pressure and height at the destination equipment or pipelines ； 2. When pumping liquid, the installation height of the equipment should be determined by the pump’s net positive suction head and the pressure drop in the suction pipeline ； 3. For towers equipped with heavy reactors heated by means other than an open flame, their installation height shall be determined based on the relationship between the tower and the reboiler as required by the process, as well as the operational requirements ； 4. The minimum clearance required for the installation and operation of the pipes at the bottom of the tower must be satisfied, and the foundation surface of the tower should be at least 200 mm above the ground level. 06 General requirements for the layout of heat exchange equipment: 1. Shell-and-tube heat exchange equipment associated with distillation towers, such as bottom reboilers and top condensers. The processes should be arranged in sequence near the distillation tower ； 2. For heat exchangers where two fluids exchange heat, it is advisable to locate them as close as possible to the pipes connecting the inlets and outlets of these two fluids ； 3. A shell-and-tube heat exchanger in which one fluid exchanges heat with several different fluids should be arranged in groups ； 4. Coolers for several different materials should be cooled with water or a coolant, and it is advisable to arrange them in groups ； 5. For heat exchange equipment arranged in groups, it is advisable to align the center lines of the support foundations. When the spacing between the supports is different, it is preferable to align the center lines of the support foundations at one end. To facilitate pipeline connection, the heat exchanger installed on the ground can also have its tube side inlet and outlet nozzles aligned along their centerlines ； 6. Heat exchange equipment should be installed on the ground as much as possible; however, when there is a large number of such devices, they can be installed on frames: 1) When floating-head heat exchangers are installed on the ground, the following requirements must be met: there should be a space of at least 0.6m on both sides of the floating head and the tube box ； There should be a clear area in front of the floating head end with a width of not less than 1.2 m ； In front of the tube box, starting from the end of the tube box, there should be a space that is at least 1.5 m longer than the length of the tube bundle. 2) When a floating-head heat exchanger is installed on a frame, the following requirements must be met: the clear height of the platform in front of the floating-head end should not be less than 0.8 m; the clear height of the platform in front of the tube box end should not be less than 1 m. The platform shall be equipped with removable railings, and space required for removing the tube bundle must also be taken into account ； The frame height should be sufficient to meet the lifting requirements for the tube sheet and the head cover of the heat exchanger. 7. To save space or facilitate operational procedures, two heat exchange units can be arranged one on top of the other. However, for two-phase flow media or heat exchangers with a shell diameter of 1.2 m or more, overlapping arrangements are not advisable ； 8. The clear distance between heat exchangers, as well as between heat exchangers and other equipment, should not be less than 0.7 m ； 9. Heat exchange equipment for heavy oil products or materials that pollute the environment should not be installed on the framework ； 10. Above heat exchangers whose operating temperature is above the auto-ignition point of the material, no other equipment should be installed if there is no floor or platform to separate them. 07 General requirements for the layout of reboilers 1. The distance between a reboiler heated by an open flame and a tower should be determined in accordance with the requirements specified in fire protection codes regarding the distance between heating furnaces and towers ； 2. Horizontal reboilers heated by steam or a heat carrier should be located near the tower, maintaining a certain height difference from it (determined by the process design); the distance between them must meet the requirements for pipeline layout, and one end of the reboiler’s tube bundle should have space and access for maintenance purposes ； 3. Vertical reboilers should be supported by a tower and installed on the side of the tower, maintaining a certain height difference from it (determined by the process design). Sufficient maintenance space should be left above it ； 4. When a tower requires multiple vertical reboilers connected in parallel, the location and installation height of the reboilers must not only meet the process requirements but also satisfy the layout requirements for the inlet and outlet manifolds, as well as facilitate operation and maintenance. 08 General requirements for the layout of air coolers 1. Air coolers (hereinafter referred to as ACs) should be located on the downwind side of the wind direction with the lowest frequency of occurrence throughout the year in the facility ； 2. The air cooler should be installed above the main corridor, on the top layer of the framework, or at the top of the tower ； 3. Air coolers should not be installed above equipment for which the operating temperature is equal to or higher than the auto-ignition point of the material, as well as above equipment used for transporting and storing liquefied hydrocarbons ； Otherwise, a partition made of non-combustible materials should be used for separation and protection ； 4. When multiple sets of air coolers are arranged together, they should be arranged in a consistent pattern; a row-based arrangement is preferred ； It should be avoided to have one part arranged in rows while another part is arranged in columns ； 5. For inclined-top air coolers, the ventilation face should not be oriented toward the prevailing wind direction in summer. Slant-roof air coolers should be arranged in rows; when arranged in rows, there should be a space of no less than 3 meters between the rows ； 6. The distance between the frame columns of two humidified air coolers or combined dry-wet air coolers arranged side by side should not be less than 3 m ； 7. Platforms should be provided at the tube box ends of the air cooler tube bank and at the location of the driving machinery ； 8. Sufficient maintenance space and access paths should be provided on the ground beside the frame or main corridor of the air cooler. 09 How to arrange air coolers to avoid thermal air circulation between them 1. Air coolers of the same type should be placed at the same height ； 2. Adjacent air coolers are arranged closely together ； 3. The grouped dry forced-air air coolers and the induced-air air coolers should be arranged separately; the induced-air air coolers should be placed on the downwind side of the wind direction corresponding to the minimum frequency of wind exposure throughout the year for the forced-air air coolers ； 4. When air-cooled exchangers of the induced-air type and those of the forced-air type are arranged together, the tube bank of the forced-air type air-cooled exchanger should be raised. 10 General requirements for the layout of heating furnaces: 1. Open-flame heating furnaces should be located concentratedly at the edge of the facility, near fire exits, and on the downwind side of the wind direction corresponding to the lowest frequency of occurrence of flammable gases, liquefied hydrocarbons, and Class B liquids throughout the year ； 2. Heating furnaces and other open-flame devices should be located together ； 3. Several heating furnaces can be arranged in rows aligned along the center line of the furnaces. The clear distance between the two heating furnaces should not be less than 3 m ； 4. When using mobile maintenance equipment to lift the furnace tubes, there should be passages and maintenance areas available for such equipment to move around in. For heating furnaces equipped with horizontal furnace tubes, on the side where the tubes are removed, the length of the maintenance area should not be less than the length of the furnace tubes plus 2 meters ； 5. The distance between the outer wall of the heating furnace and the edge of the maintenance road should not be less than 3 m ； 6. For heating furnaces equipped with steam generators, the steam drum should be located at the top of the furnace or on a framework adjacent to it ； 7. The distance between the heating furnace and its associated fuel gas separator tank and fuel gas heater should not be less than 6 m ； 8. When the heating furnace is equipped with auxiliary equipment such as air preheaters, blowers, and exhaust fans, the layout of these auxiliary devices should not hinder the maintenance of both them and the heating furnace itself ； 9. The fire separation distance between the heating furnace and the liquefied hydrocarbon equipment installed outdoors shall not be less than 22.5 m. If a solid wall made of non-combustible material is placed between the equipment, this distance can be reduced, but it must still be no less than 15 m. The height of the solid wall should not be less than 3 m, and it should be no more than 5 m away from the heating furnace; it must also prevent combustible gases from entering the furnace ； 10. When the wall facing the heating furnace in the building housing the liquefied hydrocarbon equipment or the Class A gas compressor room is a closed wall, the distance between the heating furnace and the building can be reduced, but it must not be less than 15 m. That’s all for today’s sharing; see you next time! ——————Chengdu Xinrui Fangxiao Technology Co., Ltd. is a high-tech enterprise dedicated to the research, development, production, and application of polytetrafluoroethylene and/or other polymer materials. We are actively seeking partners in the petroleum, chemical, papermaking, and shipbuilding industries. Disclaimer: The content contained herein is sourced from public sources such as the Internet and WeChat official accounts. We maintain a neutral stance regarding the views expressed in it; these views do not represent those of this account. All articles are provided for reference and informational purposes only. If there is any infringement, please contact us to have it removed.