scholarly journals Investigation of the combined process of isothermal crimping with a set of thickenings at the ends of pipe blanks

2021 ◽  
Vol 1901 (1) ◽  
pp. 012094
Author(s):  
A A Pasynkov ◽  
S N Larin ◽  
O Yu Gurova
Keyword(s):  
Author(s):  
S. R. Rakhmanov

In some cases, the processes of piercing or expanding pipe blanks involve the use of high-frequency active vibrations. However, due to insufficient knowledge, these processes are not widely used in the practice of seamless pipes production. In particular, the problems of increasing the efficiency of the processes of piercing or expanding a pipe blank at a piercing press using high-frequency vibrations are being solved without proper research and, as a rule, by experiments. The elaboration of modern technological processes for the production of seamless pipes using high-frequency vibrations is directly related to the choice of rational modes of metal deformation and the prediction resistance indicators of technological tools and the reliability of equipment operation. The creation of a mathematical model of the process of vibrating piercing (expansion) of an axisymmetric pipe blank at a piercing press of a pipe press facility is an actual task. A calculation scheme for the process of piercing a pipe plank has been elaborated. A dependence was obtained characterizing the speed of front of plastic deformation propagation on the speed of penetration of a vibrated axisymmetric mandrel into the pipe workpiece being pierced. The dynamic characteristics of the occurrence of wave phenomena in the metal being pierced under the influence of a vibrated tool have been determined, which significantly complements the previously known ideas about the stress-strain state of the metal in the deformation zone. The deformation fields in the zones of the disturbed region of the deformation zone were established, taking into account the high-frequency vibrations of the technological tool. It has been established that the choice of rational parameters (amplitude-frequency characteristics) of the vibration piercing process of a pipe blank results in significant increase in the efficiency of the process, the durability of the technological tool and the quality of the pierced blanks.


Author(s):  
Yi Han ◽  
Feng Liu ◽  
Xin Ran

In the production process of large-diameter seamless steel pipes, the blank heating quality before roll piercing has an important effect on whether subsequently conforming piping is produced. Obtaining accurate pipe blank heating temperature fields is the basis for establishing and optimizing a seamless pipe heating schedule. In this paper, the thermal process in a regenerative heating furnace was studied using fluent software, and the distribution laws of the flow field in the furnace and of the temperature field around the pipe blanks were obtained and verified experimentally. The heating furnace for pipe blanks was analyzed from multiple perspectives, including overall flow field, flow fields at different cross sections, and overall temperature field. It was found that the changeover process of the regenerative heating furnace caused the temperature in the upper part of the furnace to fluctuate. Under the pipe blanks, the gas flow was relatively thin, and the flow velocity was relatively low, facilitating the formation of a viscous turbulent layer and thereby inhibiting heat exchange around the pipe blanks. The mutual interference between the gas flow from burners and the return gas from the furnace tail flue led to different flow velocity directions at different positions, and such interference was relatively evident in the middle part of the furnace. A temperature “layering” phenomenon occurred between the upper and lower parts of the pipe blanks. The study in this paper has some significant usefulness for in-depth exploration of the characteristics of regenerative heating furnaces for steel pipes.


1968 ◽  
Vol 51 (9) ◽  
pp. 1500-1502 ◽  
Author(s):  
W.H. Stroup ◽  
A.L. Reyes ◽  
G.K. Murthy ◽  
R.B. Read ◽  
R.W. Dickerson

2016 ◽  
Vol 74 (3) ◽  
pp. 655-662 ◽  
Author(s):  
Mei Pan ◽  
Jun Zhao ◽  
Shucong Zhen ◽  
Sheng Heng ◽  
Jie Wu

Excess nitrogen in urban river networks leading to eutrophication has become one of the most urgent environmental problems. Combinations of different aeration and biofilm techniques was designed to remove nitrogen from rivers. In laboratory water tank simulation experiments, we assessed the removal efficiency of nitrogen in both the overlying water and sediments by using the combination of the aeration and biofilm techniques, and then analyzed the transformation of nitrogen during the experiments. Aeration (especially sediment aeration) combined with the biofilms techniques was proved efficient in removing nitrogen from polluted rivers. Results indicated that the combination of sediment aeration and biofilms, with the highest nitrogen removal rate from the overlying water and sediments, was the most effective combined process, which especially inhibited the potential release of nitrogen from sediments by reducing the enzyme activity. It was found that the content of dissolved oxygen in water could be restored on the basis of the application of aeration techniques ahead, and the biofilm technique would be effective in purifying water in black-odor rivers.


2012 ◽  
Vol 441 ◽  
pp. 589-592
Author(s):  
Zhi Min Fu ◽  
Yu Gao Zhang ◽  
Xiao Jun Wang

A combined process of biological wriggle bed and ozone biological aerated filter was utilized to treat textile wastewater. Results showed that COD removal efficiency was almost 90.4%. The average effluent COD was 85.87 mg/L. The effluent colority was 64-32 times. This study indicated that the combined process is potentially useful for treating textile wastewater.


2015 ◽  
Vol 8 ◽  
pp. 45-54 ◽  
Author(s):  
Abdurrahman Akyol ◽  
Orhan Taner Can ◽  
Mahmut Bayramoglu

Sign in / Sign up

Export Citation Format

Share Document