Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

Experimental study on air added technology and increasing discharge distance of small diameter sludge
discharge pipe in dredging engineering
Jiacheng Luo1, Panpan Li1, Chaozhe Yuan1*, Yuchi Hao1, Runli Tao1,Jie Yang2
1

National Engineering Research Center of Dredging Technology and Equipment, shanghai, China.
2CCCC SDC (Fujian) Communication Construction Engineering Co., Ltd, Xiamen, Fujian, China.

*Corresponding author

ABSTRACTlayout and can be implemented quickly.

Small cutter suction dredgers have been widely used in environmental
dredging of rivers and lakes. However, due to the insufficient pumping
pressure and large transmission resistance, the transmission distance ofthe cutter suction dredgers can not meet the requirements of engineering.
According to the actual demand, this paper carried out the research on
the air added technology of small diameter, analyzed the influence of theair added technology on the pipeline transportation, and improved theproblem of short transmission distance caused by the large transportation
resistance of the small diameter cutter suction dredger. At the same time,relying on the actual project, this paper carried out the field test of air
added technology of DN400 diameter sludge discharge pipeline, andresearched the location of air added point along the pipeline, three air
adding methods, and the comparison of economic benefits between thescheme of air added and pump. The results show that the air added
technology is beneficial to improve the transportation distance of small
cutter suction dredger and reduce the unilateral cost of dredging
transportation.

Air added in pipeline is a technology to boost pipeline transportation bychanging the slurry resistance inside the pipeline. The technology canreduces the resistance between the pipeline and the slurry effectively. Asa drag reducer, air has the advantages of no pollution, easy access and notreatment. The air added equipment has the characteristics of simple
installation, simple operation and low equipment loss. Therefore, there
are many scholars have studied pipeline air added technology.
Pipeline air boosting drag reduction technology was first studied andapplied by Japan in the 1960s, and various specifications of air boosting
pump ships was manufactured for production and test. In the 1980s,Chinese scholars also began to study the air added technology of pipelinetransportation. At present, most of the research focuses on the theory andindoor test stage of air added and transportation. Yu LW (2006a), Xiong
T (2011a; 2011b) and others analyzed the mechanism of air injection
drag reduction; Yu LW(2006b), Zhu HH (2008) and Tang B (2008)
carried out indoor experimental research on the aerating technology andobtained the parameter characteristics of the aerating technology; Tang
B (2011) and Cai Y (2013) improved the air added device and verified
its effectiveness; only a few scholars had conducted on-site experimental
research, such as Lin Y (2019) and others, who had carried out on-site
tests of relevant air added and transmission technologies in Xiamen
Malan Bay ecological restoration and dredging project in the past.
Therefore, there are still great limitations of the study on the pipelinetransportation and air added technology.

KEY WORDS: Cutter Suction Dredger; pipeline transport; airaided conveying; transport resistance
INTRODUCTION
Dredging engineering is inseparable from the long-distancetransportation of slurry. Improving the transportation performance ofpipeline has always been the key research direction of dredging andfilling engineering. The methods to improving the conveying
performance mainly include the following ways: optimizing theperformance of power equipment and improving the working efficiencyof them; changing the basic parameters of the transmission pipeline,
optimizing the pipeline layout, and adopting small resistance pipeline;
improving the characteristics of conveying slurry and reducing theinternal resistance of slurry. The first two methods require a lot of capital
investment for equipment renewal and iteration, while the way of
reducing slurry conveying resistance has little change to the originalIn view of the shortcomings of the current research, relying on
Shimen’ao project, this paper carried out the application research of jet
aeration mode in pipeline aeration boost and drag reduction technology,
carried out the field test of the increase discharge effect of jet aerator
under different aeration conditions, compared and analyzed the increasedischarge effect of jet aerator with different aeration forms, aeration
positions and aeration diameters. It provides a new technical scheme andkey process parameters for long row spacing transportation ofenvironmental dredging.

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