Resending 【One Question per Day】1.7 Brief answer question: What are the requirements for the installation quality of towers?

(1) Tower body: The tower body must be vertical; the allowable inclination is generally no more than one in a thousand. Otherwise, dead zones will form on the tray surface. In the case of distillation towers with small diameters, if the trays are installed in sections first and then assembled, any deviation in the verticality of the tower body will directly affect the levelness of all the trays in the tower, thereby reducing its efficiency. (2) Tray: The tray must be level, and its levelness, as measured with a level, shall not exceed ±2 millimeters. If the tray is not level, it will result in uneven liquid layer heights on the tray surface. The rising steam inside the tower can easily pass through the areas where the liquid layer is shallower, thereby reducing the efficiency of the tray. (3) Overflow port: The distance between the overflow port and the lower tray is determined based on the production capacity and the height of the overflow weir of the lower tray. However, it is necessary to ensure that the overflow port is inserted into the liquid in the receiving tray to seal off the rising steam. If the overflow port is too close to the lower tray, it may prevent the reflux from the upper tray from flowing smoothly into the lower tray, resulting in an increase in the liquid level on the upper tray and an increase in pressure on the lower tray; in severe cases, this can lead to flooding. If the overflow port is too high, exceeding the height of the overflow weir, the rising steam takes a shortcut, rising directly from the overflow pipe to the upper tray levels, failing to serve as a liquid seal and thus affecting the efficiency of the trays. During installation, various specific types of trays have different requirements; failing to follow these requirements may lead to a **decrease in the tower’s production efficiency**.

Installation methods for tower-type equipment 1. Construction preparation 1.1 Before installing the equipment, it is necessary to inspect the equipment foundation to ensure that the equipment is installed on a suitable foundation, thereby guaranteeing the quality of the installation. Grind the location where the shims for the equipment installation foundation are placed to achieve a certain level of flatness. 1.2 The concrete of the equipment foundation must have reached the design strength and meet the requirements for lifting; the foundation shall have clear and accurate center lines and elevation lines. Check whether the longitudinal center line of the tower is clear and correct, and whether the markings are visible. 1.3 Clear all debris from the areas surrounding the site, level the ground, and ensure the roads are clear. 1.4 All kinds of construction machinery, measuring instruments, materials, and tools shall be transported to the site as planned. The accuracy of the instruments and measuring devices used for measurement and inspection must meet the accuracy standards specified by the **Metrology Bureau, and they must pass regular inspections. Organize the equipment installers to study the construction drawings and relevant technical specifications carefully, taking into account the actual conditions at the construction site; conduct technical and safety briefings, and fill in all relevant installation records. To ensure the smooth lifting of tower-type equipment, a lifting leadership team should be established based on the difficulty level of lifting the equipment, with clear division of tasks and assigned responsibilities for each person. 1.5 Select appropriate lifting equipment based on the weight of the equipment, as well as suitable lifting rigging. For old steel cables and temporary lifting lugs and other load-bearing components, necessary non-destructive testing should be carried out, and all load-bearing steel cables must be pre-tightened. 1.6 Application for inspection upon installation of pressure vessels. 1.7 Thoroughly familiarize yourself with the technical documents and installation instructions provided with the random device. 1.8 Before installation, carefully inspect the appearance of the equipment and the orientation of its pipe openings; clean the interior thoroughly, and temporarily seal all pipe openings to prevent foreign objects from entering. 2. Construction procedures 2.1 Re-inspection and acceptance of foundations 2.1.1 Measurement records should be available at the time of foundation handover. On the foundation, the elevation reference line as well as the longitudinal and transverse center lines of the foundation should be clearly marked. Coordinates axes should be indicated on the building, and settlement observation points should be provided for the foundations of important equipment. 2.1.2 Conduct a visual inspection of the foundation; it must be free from defects such as cracks, honeycombing, voids, and exposed rebar. 2.1.3 In accordance with the relevant civil engineering foundation drawings and technical documents for the equipment, re-measure and inspect the dimensions, location, and elevation of the foundations; the allowable deviations shall comply with the provisions in the table below. The acceptance results must be signed by representatives from the civil engineering unit, the project owner’s representative, the supervision company, and the installation unit. 2.1.4 Before installing the equipment, the foundation should be prepared as follows: 2.1.4.1 For foundation surfaces that require secondary grouting, the surface should be roughened; there should be no oil stains or loose layers on the surface. 2.1.4.2 The foundation surface at the location where shims are to be placed should be leveled, with an allowable deviation in levelness of mm/m. 2.1.4.3 Debris such as gravel and soil, as well as standing water, in the bolt holes must be completely removed. Table of allowable deviations for the dimensions and position of equipment foundations
Item name Allowable deviation (mm)
1 Foundation coordinate position (horizontal and vertical axes): ±20
2 Elevation of different planes of the foundation: +0–20
3 Dimensions of the upper surface of the foundation: ±20; Dimensions of the upper surface of protrusions: –20; Dimensions of recesses: +20
4 Levelness of the upper surface of the foundation: 5/m over the entire length
5 Vertical deviation: 5/m over the entire height
6 Elevation of embedded foot bolts (top end): +20, –0; Center distance (at the base and top): ±2
7 Center position of holes for embedded foot bolts: ±10; Depth: +20, –0; Perpendicularity of hole walls (over the entire depth): 10
8 Elevation of embedded plates: +20, –0; Center position: 5

2.2 Basic requirements for installing shims
2.2.1 The principle for arranging shim sets is as follows: One set should be placed on each side of the foot bolts, with the shims positioned as close to the foot bolts as possible. When the distance between foot bolts is less than 300 mm, one set of shims can be placed on the same side of all the foot bolts. The distance between adjacent shim sets can be determined based on specific factors such as the weight of the equipment, the structure of the base, and its layout; it is generally around 500 mm. The type of shimming is determined based on factors such as the equipment weight, as well as the shape and size of the base. 2.2.2 The surface of the shims should be flat, free of oxide scale, burrs, etc. The surface finish of the inclined shim’s inclined surface should be no lower than ▽3, with a slope of generally 1/20 to 1/10. 2.2.3 Shim blocks should be used in pairs; when combined with flat shim blocks to form a set of shims, the total number of layers should generally not exceed four, and thin shim blocks should be placed between the shim blocks and the thicker flat shim blocks. The height of the shim set is generally 30–70 mm. 2.2.4 The shims should be placed directly on the foundation (embedded plate), with even contact with the foundation (embedded plate); the contact area should be no less than 80%. The allowable deviation for the levelness of the top surface of the flat shims is 2 mm/m; a level and a spirit level are used for inspection, and the elevation of the top surface of each shim set should match the actual installation elevation of the equipment’s bottom surface. 2.2.5 After the equipment is leveled, the shim set should protrude 10–30 mm from the base. For the shims on both sides of the anchor bolts, the length of each shim that extends into the surface of the equipment base should exceed that of the anchor bolt. It is also necessary to ensure that the load on the device’s base is distributed evenly. If the contact area between the bottom surface of the device’s base and the shims is insufficient, the shims should be arranged in such a way that the base sits in the center of the bearing surface provided by the shims. 2.2.6 Level the equipment using shims; after alignment, tap the shim set with a hammer to check its tightness – there should be no looseness. When checked using a 0.05 mm feeler gauge, the total length inserted from both sides at the same cross-section of the shims, between the shims and between the shims and the bottom surface of the base, must not exceed 1/3 of the length (width) of the shim. After passing the inspection, spot welding should be carried out immediately on both sides of the shim set to secure them together; welding shall not be performed between the shims and the base of the equipment.

1.1 Before installing the equipment, the equipment foundation must be inspected and approved to ensure that the equipment is installed on a suitable foundation, thus guaranteeing the quality of the installation. Grind the location where the shims for the equipment installation foundation are placed to achieve a certain level of flatness. 1.2 The concrete of the equipment foundation must have reached the design strength and meet the requirements for lifting; the foundation shall have clear and accurate center lines and elevation lines. Check whether the longitudinal center line of the tower is clear and correct, and whether the markings are visible. 1.3 Clear all debris from the areas surrounding the site, level the ground, and ensure the roads are clear. 1.4 All kinds of construction machinery, measuring instruments, materials, and tools shall be transported to the site as planned. The accuracy of the instruments and measuring devices used for measurement and inspection must meet the accuracy standards specified by the **Metrology Bureau, and they must pass inspections on schedule. Organize the equipment installers to study the construction drawings and relevant technical specifications carefully, taking into account the actual conditions at the construction site; conduct technical and safety briefings, and fill in various installation records. To ensure the smooth lifting of tower-type equipment, a lifting leadership team should be established based on the difficulty level of lifting the equipment, with clear division of tasks and assigned responsibilities for each person. 1.5 Select appropriate lifting equipment based on the weight of the equipment, as well as suitable lifting rigging. For old steel cables and temporary lifting lugs and other load-bearing components, necessary non-destructive testing should be carried out, and all load-bearing steel cables must be pre-tightened. 1.6 Application for inspection upon installation of pressure vessels. 1.7 Thoroughly familiarize yourself with the technical documents and installation instructions provided with the random device. 1.8 Before installation, carefully inspect the appearance of the equipment and the orientation of its pipe openings; clean the interior thoroughly, and temporarily seal all pipe openings to prevent foreign objects from entering.

1) Tower body: The tower body must be vertical; the typical inclination should not exceed one thousandth of the total height of the tower, otherwise dead zones will form on the tray. . (2) Tray: The tray requires a high level of accuracy; the levelness, as measured with a level, should not exceed ±2 millimeters. (3) Overflow port: The distance between the overflow port and the lower tray should be determined based on the production capacity and the height of the overflow weir on the lower tray; however, it is necessary that the overflow port be submerged in the liquid within the liquid receiving tray in order to seal off the rising vapor.

1. Properly process the construction materials and strive to save steel pipes; only by conserving the use of pipes can efficiency be achieved. It is best to mark the pipes while processing them, as this will save time during installation. 2. During pipeline processing, some personnel can be assigned to install pipe supports and hangers, so that the processed pipes can be installed directly. After the supports and hangers have been installed, the main pipeline should be installed first; try to assemble the branch pipes on the ground before connecting them to the main pipeline. This can save labor costs. 3. Pay attention to safety, especially when working at heights and using electricity, as well as to avoiding mechanical injuries from tools such as toothed saws, thread-forming machines, and slotting machines. When slotting, be careful about the depth and shape of the slots to prevent leaks resulting from poor work quality; likewise, pay attention to the quality of the threads formed. After the pipeline network is installed, a pressure test must be conducted to ensure that there are no leaks in the network. 4. When working in conjunction with other specialized contractors, it is essential to pay attention to the protection of finished products. When installing ceilings during renovation work, holes must be left in the appropriate locations for the sprinkler heads, to ensure that none of them are missed. After the system is installed, it is essential to conduct linkage tests to ensure its proper operation. The wet alarm valve should be installed in accordance with the instructions to avoid installation errors. During installation, attention should be paid to adjusting the rotation direction of the spray pump and the installation direction of the check valves on the pipes.

I. Permissible deviations for tower installation: 1. Permissible deviation of the center line: 5 mm； 2. The allowable deviation for elevation is ±5mm ； 3. The allowable deviation for plumbness is H/1000 mm, and shall not exceed 30 mm. II. The anchor bolts shall comply with the following requirements: 1. The contact between the nut and the washer, as well as between the washer and the equipment base, must be tight ； 2. After tightening the nut, the bolt should protrude from it by at least two threads, with even stress distribution ； 3. Oil, scale, and other contaminants on the anchor bolts should be removed completely; the threads must be free from damage or rust, and a small amount of grease should be applied to them. III. The levelness and positional tolerance of the internal components within the tower shall meet the standards specified in the design requirements.

This post was last edited by zxsaqwe on 2016-1-10 at 19:17. The verticality of the tower structure must meet the specification requirements, and the levelness of the tower plates must also meet such requirements