Experimental study on anti‐crystallization law of tunnel transverse flocking drainpipe at different velocities

Abstract

With the increasing of the tunnel operation life, various diseases of the tunnel are gradually highlighted, especially the lining cracking and leakage caused by the crystal blocking pipe of the drainage system, which brings serious hidden trouble to the safe operation of the tunnel. In order to solve the problem of crystal plugging of horizontal drainage pipe in tunnel, the transverse drainage pipe of the tunnel was taken as the research object, combined with the field survey data, and the indoor test was used to analyze the anti‐crystallization law of flocking drainage pipe at different velocities. The results showed that the flocking drainage pipes had an anti‐crystallization effect, and the anti‐crystallization efficiency could be increased by more than 50% compared with the ordinary drainage pipes, and the flow rate at 6.82 cm/s could reach more than 60%. At the flow rate of 5.46 cm/s, the crystallization on flocking drainage pipes at the later stage of the test remained basically unchanged and was less than that on ordinary drainage pipes. The change in the weight of crystals on the flocking drainage pipes was approximately sinusoidal, and the change period was different at different flow rates; among which, the change period of crystallization on the flocking drainpipe was shorter when the villi length was shorter at low flow rates.

Optimization Study of Fluffy Materials Flocking Drainage Pipes to Resist Blockage Based on MD Binding Energy

“…Through the above analysis, given the binding energy between the four materials and the crystallized ion aqueous solution, we can select the PP with low binding energy as the materials for drainage pipes; given the binding energy between the four materials and the two typical growth crystals of calcium carbonate, we can select the PP and SiC as the materials for drainage pipes. From the analysis of MD simulation results, we speculated that SiC had the best anti-crystallization effect in drainage pipe flocking, however, the result of the actual indoor macroscopic test [15] was contrary. Thus, the geometric property of the fluffy material (Figure 3) played a major role in the anti-crystallization effect of drainage pipes flocking.…”

“…Through the above analysis, given the binding energy betw and the crystallized ion aqueous solution, we can select the PP w as the materials for drainage pipes; given the binding energy betw and the two typical growth crystals of calcium carbonate, we can s the materials for drainage pipes. From the analysis of MD simula lated that SiC had the best anti-crystallization effect in drainage p the result of the actual indoor macroscopic test [15] was contrar property of the fluffy material (Figure 3) played a major role in effect of drainage pipes flocking. Therefore, for better anti-crysta and SiC can be used as the materials for flocking drainage pipes, shall have a good geometrical property (smooth surface and stra direction) so as to maximize the anti-crystallization effect of the dr…”

“…Drainage p tals mainly include insoluble calcite crystals, and the PEG-b-PAA-b-PS, poly(ethyl col)-block-poly(acrylic acid)-block-poly(styrene) can prevent the phase transiti vaterite to calcite [7]; in the presence of biopolymer, the relative content of vat creases with the application of ultrasonic treatment [8]; ultrasonic treatment m gathered calcium carbonate crystals more fragile [9]; RS1600, a green corrosion in makes the crystal structure of calcium carbonate change from calcite to vaterite cleaning solvent of organic acid reagents of single molecule carboxylic acids wit centration of 2000 ppm and a dichromate index of 17.71% and that of polymeri boxylic acids can effectively remove the karst crystal of a drainage pipe system w suring environmental protection [11]. Through a large number of 1:1 indoor mo and numerical simulation analyses, Liu Shiyang, et al [12][13][14][15][16] studied the feasib reliability of drainage pipe flocking for resisting blockage from a macro perspect some good flocking parameters were obtained. The real solution to the attachmen tals of drainage pipes depends on the micro binding energy between the crystals drainage pipe.…”

Parameter optimization of anti-crystallization flocking drainage pipe based on macro force and displacement characteristics of villus

“…In the numerical simulation, three kinds of villus diameter (0.6 mm, 1.0 mm, and 1.4 mm) and four kinds of villus length (5 mm, 10 mm, 15 mm, and 20 mm) were set. Combined with the field investigation results, the flow rate of 2 cm/s [22,23] was set, and the villus was distributed at the bottom and side of the drainage pipe. The villus parameters of the drainage pipe were optimized from two aspects of stress and displacement by using ANSYS fluid structure coupling calculation module.…”

“…The cleaning solvents of single-molecule carboxylic acid organic acid reagent and polymeric carboxylic acid organic acid reagent with concentrations of 2000 ppm and dichromate indexes of 17.71% can effectively remove karst crystals from drainage systems on the premise of ensuring green environmental protection [19]. Based on the natural phenomenon, Liu et al [20][21][22][23][24] put forward the technology of flocking drainage pipe to prevent crystal clogging from the structure of drainage pipe. At the same time, a large number of indoor tests and numerical simulation were carried out, and some useful results were obtained [25].…”