Extraction tower
Extraction tower: In the huge installation area of petroleum refining, chemical industry, pharmaceutical and other process industries, there is a kind of cylindrical equipment, that is, the extraction tower. As the core equipment to realize the separation, purification and chemical reaction of the mixture, the extraction tower makes the gas and liquid and other countercurrent contact through the internal precise tower plate to complete the key processes such as distillation, absorption and desorption. Its separation efficiency directly determines the purity, yield and economic benefits of the whole device of the final product. The accuracy of the extraction tower manufacturing and installation, especially its verticality, internal horizontality, takeover orientation and other geometric parameters, is the key to ensuring its safe, efficient and long-term operation.
The importance of three-dimensional detection
With the increasingly strict engineering standards and the popularization of digital delivery, the implementation of three-dimensional precision testing of extraction towers has become a rigid requirement. Traditional testing methods, such as perpendicular lines, level meters, etc., are relatively low in efficiency, and it is difficult to obtain comprehensive and quantitative spatial data, and it is difficult to meet the requirements of data-driven decision-making in modern projects. Digital three-dimensional detection establishes a "digital twin" model for the extraction tower through high-precision spatial coordinate measurement, which realizes the accurate control of the whole life cycle from manufacturing, installation to operation and maintenance. It is an indispensable technical cornerstone for preventing deformation, guiding installation, verifying quality, supporting transformation and other links.
Figure 1: API measurement service extraction tower measurement site
API laser tracker three-dimensional detection solution
With the unique advantages of large-scale, high-precision and real-time feedback, the API laser tracker can meet the needs of the precision geometry detection of the extraction tower. Its core testing content includes:
1. Macro shape tolerance detection
√ Straightness and verticality of the tower: measure the spatial trajectory of the section and the center line of the whole tower to ensure that it meets the design requirements;
√ Roundness and diameter of the cylinder: analysis of the roundness of each segment port and typical cross-section, control the ellipse, and ensure the installation conditions of the internal parts.
2. Installation accuracy detection of key internal components
√ Support circle/support beam detection: height and horizontal measurement are the basis of the level of the tower plate or packing bed, which directly affects the uniformity of gas-liquid distribution;
√ Tower plate assembly detection: accurate measurement of the flatness of the tower plate, the height consistency of the overflow weir, the verticality and spacing of the liquid plate;
√ Coaxiality of the inner part: evaluation of the center of the multi-layer inner part and the theoretical axis of the tower.
3. External interface and auxiliary structure detection
√ Take over flange: center coordinates, flange normal direction (amuth angle and tilt angle), flatness and bolt hole distribution circle detection;
√ Platform ladder and tower pipeline: spatial position and interference inspection.
4. Manufacturing and installation process control
√ Segmented pre-assembly and ring seam group pairing: guide the on-site group pair assembly after the large extraction tower segmented manufacturing, and control the amount of misalignment and gap uniformity;
√ Foundation and skirt seat: Check the surface flatness and the position of the base bolt hole on the foundation board.
Figure 2: API series laser tracker (model from left to right: iLT / Radian Plus / Radian Pro / Radian Core / iLTx)
Introduction to the technical advantages of API laser tracker
Among many measurement tools, API brand Radian and iLT series laser trackers provide accurate and efficient solutions for tower detection with excellent engineering design and stable measurement performance.
Radian laser tracker is a high-precision 3D/6D measuring instrument with a large measurement range. It has a micron (μm) level accuracy, a measurement radius of more than 80 meters, and a super-large measurement angle range. It is compact and compact in design, and can be installed and work in any posture, which can fully Meet the requirements of measurement accuracy, efficiency, range, etc. in each link in the extraction tower measurement; among them, Radian Plus and Radian Core models also adopt battery-powered and wireless communication systems, which can completely get rid of the constraints and troubles of various cables and make the whole measurement process easier. In control.
Just set up the Radian laser tracker next to the standard to be measured to start the operation and measurement; when measuring, set the Radian laser tracker in the system coordinate system, and the emitted laser will track the SMR (tracker target) in the operator's hand. The operator only needs to hold the target and touch the data to be collected. For the part to be tested, the tracker will automatically collect the three-dimensional measurement data of the counting point, send it to the laptop and record it in the measurement software for subsequent processing and analysis.
After the data information of all the parts to be tested is collected, the operator can set, analyze and compare these data with the nominal value in the measurement software, so as to obtain the error of the actual value and achieve the effect of detection.
Figure 3: Radian (left) and iLT (right) laser trackers
The newly launched iLT laser tracker further reduces the overall size of the laser tracker by 50% (compared with the Radian series) on the basis of fully wireless measurement. The weight of the whole machine is only 4.9Kg, giving full play to the portable properties, fully satisfying and suitable for going out, outdoor, Application environments such as narrow space and multi-machine integration.
Measurement operation process
1. On-site program formulation and base station erection
According to the size of the extraction tower and the detection focus, plan the tracker station, and usually choose a location that can see most of the detection areas and the foundation is stable. Based on the high integration and portability of API laser tracker, it can be flexibly installed.
2. Establish a global unified coordinate system
On the base or skirt of the extraction tower, measure at least three reference points of known design coordinates (or establish a temporary benchmark) through supporting software (such as SpatialAnalyzer, Polyworks, Metrolog, Verisurf, MeasurePro, etc. ) Carry out the best fitting alignment of the coordinate system and establish an absolute benchmark for detection.
Figure 4: Extraction tower measurement site
3. Accurate measurement of key features and real-time adjustment guidance
The operator only needs to touch the measurement position with the tracker target ball with a built-in prism in his hand (please refer to Figure 4) to record the spatial coordinate detection of the position to be tested and transmit it to the measurement software on the laptop for follow-up analysis. In addition to using traditional target balls for measurement, API laser tracker measurement accessories can also be selected to detect relevant data according to actual measurement needs. ( For example: cooperate with vProbe probe to implement hidden point measurement; cooperate with iScan3D for fast point cloud acquisition; cooperate with ActiveTarget active target to realize automated data collection; cooperate with STS six-dimensional sensor to achieve accurate measurement of 6DoF data, etc., please refer to Figure 5 and Figure 6) .
Figure 5: API laser tracker measurement accessory (from left to right: iScan3D / ActiveTarget / STS / vProbe)
Figure 6: Introduction to the function of the tracker measurement accessory
4. Measurement data analysis
Through the measured point cloud data, the corresponding lines, surfaces, bodies, etc. can be constructed, and the measurement data analysis can be carried out according to the detection needs.
Figure 7: Measurement site of extraction tower
Figure 8: Measurement site of extraction tower
Survey site
The on-site operation content of the measurement case in this paper is: spatial trajectory measurement of the center line of the extraction tower segment.
When measuring, the operator first places the API laser tracker at one end of the extraction tower, then collects spatial points on the inner wall of the tower cylinder, and synthesizes the corresponding circle according to different positions to calculates the center position of the circle; after the calculation of multiple center positions, the straightness of the center line can be evaluated according to the corresponding XYZ value, from And achieve the purpose of testing.
Figure 9: Measurement data and analysis
Figure 10: Measurement data and analysis
Sum up
With excellent measurement accuracy, strong environmental adaptability, intelligent human-computer interaction and efficient real-time feedback ability, the API laser tracker solution has upgraded the detection experience in the process of extraction tower manufacturing and installation to a new dimension.
It is not only a "diagnostic device" to find problems, but also a "navigator" to guide accurate construction. The API laser tracker ensures the horizontal placement of each layer of the tower, the precise position of each flange, and even the straight standing of the whole extraction tower. It has greatly shortened the construction period, eliminated potential operation risks, and provided a solid measurement guarantee for the safe, efficient and long-cycle operation of large-scale industrial installations.
Figure 11: API Company Headquarters Building
About API
The API brand was founded by Dr. Kam Lau in Rockwell, Maryland, USA in 1987. It is the inventor of laser trackers and holds many patents for the world's leading measurement technology. It is a leader in the field of precision measurement technology. Since its establishment, API has been committed to the field of machinery manufacturing. In the research and development and production of dense measurement instruments and high-performance sensors, the products have been widely used in advanced manufacturing fields around the world, and are in a leading position in the high-precision standards of coordinate measurement and machine tool performance test.