scholarly journals Automated technique for high-pressure water-based window cleaning and accompanying parametric study

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0242413
Author(s):  
Youngjoo Lee ◽  
Daesung Kwon ◽  
Changmin Park ◽  
Myoungjae Seo ◽  
TaeWon Seo
Keyword(s):  
High Pressure ◽  
Evaluation Method ◽  
Water Pressure ◽  
Reaction Force ◽  
Field Tests ◽  
Image Data ◽  
Spray Angle ◽  
Cleaning Performance ◽  
Pressure Water ◽  
Automated Technique

The maintenance of buildings has become an important issue with the construction of many high-rise buildings in recent years. However, the cleaning of the outer walls of buildings is performed in highly hazardous environments over long periods, and many accidents occur each year. Various robots are being studied and developed to reduce these incidents and to relieve workers from hazardous tasks. Herein, we propose a method of spraying high-pressure water using a pump and nozzle, which differs from conventional methods. The cleaning performance parameters, such as water pressure, spray angle, and spray distance, were optimized using the Taguchi method. Cleaning experiments were performed on window specimens that were contaminated artificially. The cleaning performance of the proposed method was evaluated using the image-evaluation method. The optimum condition was determined based on the results of a sensitive analysis performed on the image data. In addition, the reaction force due to high pressure and impact force on the specimens were investigated. These forces were not sufficient to affect the propeller thrust or cause damage to the building’s surface. We expect to perform field tests in the near future based on the output of this research.

scholarly journals Analysis on Water Inrush Process of Tunnel with Large Buried Depth and High Water Pressure

Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 134 ◽  
Author(s):  
Weimin Yang ◽  
Zhongdong Fang ◽  
Hao Wang ◽  
Liping Li ◽  
Shaoshuai Shi ◽  
...  
Keyword(s):  
High Pressure ◽  
Model Test ◽  
Water Pressure ◽  
Water Inrush ◽  
High Water ◽  
Surrounding Rock ◽  
Karst Cave ◽  
Tunnel Excavation ◽  
Pressure Water ◽  
High Water Pressure

In order to explore the catastrophic evolution process for karst cave water inrush in large buried depth and high water pressure tunnels, a model test system was developed, and a similar fluid–solid coupled material was found. A model of the catastrophic evolution of water inrush was developed based on the Xiema Tunnel, and the experimental section was simulated using the finite element method. By analyzing the interaction between groundwater and the surrounding rocks during tunnel excavation, the law of occurrence of water inrush disaster was summarized. The water inrush process of a karst cave containing high-pressure water was divided into three stages: the production of a water flowing fracture, the expansion of the water flowing fracture, and the connection of the water flowing fracture. The main cause of water inrush in karst caves is the penetration and weakening of high-pressure water on the surrounding rock. This effect is becoming more and more obvious as tunnel excavation progresses. The numerical simulation results showed that the outburst prevention thickness of the surrounding rock is 4.5 m, and that of the model test result is 5 m. Thus, the results of the two methods are relatively close to each other. This work is important for studying the impact of groundwater on underground engineering, and it is of great significance to avoid water inrush in tunnels.

Tests on High-Pressure Water Rotational Jetting Ventilation Cooling Characteristic

2012 ◽  
Vol 594-597 ◽  
pp. 2073-2076
Author(s):  
Zhong Fei Ma ◽  
Li Chen ◽  
Fu Qin Wang
Keyword(s):  
Experimental Study ◽  
High Pressure ◽  
High Temperature ◽  
Cooling Rate ◽  
Temperature Difference ◽  
Water Pressure ◽  
Obvious Effect ◽  
Guide Vanes ◽  
Parabolic Growth ◽  
Pressure Water

In order to improve the cooling effect and practical applicability of falling temperature technique on high-temperature workplaces, the aeration and cooling principle of the high pressure water rotational jetting ventilation were analysed, and the experimental study was carried out. The results show that water pressure and cooling rate are an approximation of parabolic growth relationship, different structure of jet tube and temperature difference on water and gas also have an obvious effect on the cooling amplitude and air quantity. the guide vanes installed may improve effect of ventilation and cooling the capacity on high pressure water rotational jetting.

Jet Piercing of Oil Sands

1981 ◽  
Vol 103 (4) ◽  
pp. 330-335 ◽  
Author(s):  
R. R. Gilpin ◽  
E. M. Gates
Keyword(s):  
Experimental Investigation ◽  
High Pressure ◽  
Oil Sands ◽  
Dynamic Pressure ◽  
Field Tests ◽  
Pulse Frequency ◽  
Depth Of Penetration ◽  
Water Jets ◽  
Pressure Water ◽  
Pressure Nozzle

This paper describes the results of an experimental investigation of the penetration of oil sands by continuous and pulsed high-pressure water jets. Both laboratory and field tests were carried out to determine the influence of the jet dynamic pressure, nozzle diameter, pulse frequency, and total jetting time upon the depth of penetration.

scholarly journals The implosion of cylindrical shell structures in a high-pressure water environment

2013 ◽  
Vol 469 (2160) ◽  
pp. 20130443 ◽  
Author(s):  
C. M. Ikeda ◽  
J. Wilkerling ◽  
J. H. Duncan
Keyword(s):  
High Pressure ◽  
Cylindrical Shell ◽  
Time Scale ◽  
Water Pressure ◽  
Water Environment ◽  
Mode Number ◽  
Shell Structures ◽  
Internal Diameter ◽  
Cross Sectional ◽  
Pressure Water

The implosion of cylindrical shell structures in a high-pressure water environment is studied experimentally. The shell structures are made from thin-walled aluminium and brass tubes with circular cross sections and internal clearance-fit aluminium end caps. The structures are filled with air at atmospheric pressure. The implosions are created in a high-pressure tank with a nominal internal diameter of 1.77 m by raising the ambient water pressure slowly to a value, P c , just above the elastic stability limit of each shell structure. The implosion events are photographed with a high-speed digital movie camera, and the pressure waves are measured simultaneously with an array of underwater blast sensors. For the models with larger values of length-to-diameter ratio, L / D 0 , the tubes flatten during implosion with a two-lobe (mode 2) cross-sectional shape. In these cases, it is found that the pressure wave records scale primarily with P c and the time scale (where R i is the internal radius of the tube and ρ is the density of water), whereas the details of the structural design produce only secondary effects. In cases with smaller values of L / D 0 , the models implode with higher-mode cross-sectional shapes. Pressure signals are compared for various mode-number implosions of models with the same available energy, P c V , where V is the internal air-filled volume of the model. It is found that the pressure records scale well temporally with the time scale , but that the shape and amplitudes of the pressure records are strongly affected by the mode number.

Study on Automatic Monitoring Technology of Tunnel Crossing Coal Bed and Gas

2014 ◽  
Vol 488-489 ◽  
pp. 778-781
Author(s):  
Cong He
Keyword(s):  
Evaluation Method ◽  
Water Pressure ◽  
Automatic Monitoring ◽  
High Water ◽  
Western China ◽  
Coal Bed ◽  
Key Factors ◽  
Pressure Water ◽  
Mixing Method ◽  
Specific Implementation

Based on a tunnel in western China as a project, with high water pressure, water-rich, karst features and other projects, launched grouting water research, the cement-silicate slurry mixing method for determining the mixing ratio to ensure the effectiveness and construction safety grouting key factors, as well as the specific implementation grouting effect evaluation method has important theoretical and practical value for the design and construction of similar tunnels provide a reference.

scholarly journals Field Study on the Waterstop of the Rodin Jet Pile Method in a Water-Rich Sandy Gravel Stratum

2019 ◽  
Vol 9 (8) ◽  
pp. 1709
Author(s):  
Chengli Guan ◽  
Yuyou Yang
Keyword(s):  
High Pressure ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Field Tests ◽  
High Water ◽  
High Water Content ◽  
Sandy Gravel ◽  
Ultra High Pressure ◽  
Jet Grouting ◽  
Silty Soils

Due to the increasing depths of underground urban construction, the surrounding environment and hydrogeological conditions are becoming increasingly complex, and conventional high-pressure rotary jet grouting has become unable to meet construction needs. At present, Rodin jet pile (RJP) ultra-high-pressure rotary jet grouting has been widely used as a grouting reinforcement method for deep and large foundations in silty soils, fine sands and clay strata; however, there have been no successful applications in a sandy gravel stratum with high water content (namely, water-rich sandy gravel stratum). Therefore, this paper uses the ventilating shaft in a section of the Beijing Metro as the construction background to carry out field tests on the RJP ultra-high-pressure rotary jet grouting method and waterstop in a water-rich sandy gravel stratum. Through a series of experiments monitoring the formation deformation and pore water pressure and exposing the pile diameter, pile occlusion, pile strength, and permeability of the test pile construction process, it is believed that, for the RJP ultra-high-pressure construction method in a water-rich sandy gravel stratum, reliable jet solidification can occur, the joint between jets can be achieved, the solid strength can reach 10 MPa or higher, and the permeability coefficient can reach 10−8 cm/s. Therefore, RJP ultra-high-pressure rotary jet grouting can be applied as a waterstop method in water-rich sandy gravel stratum.

Study on Grouting Comprehensive Technical of Karst Tunnel with Water-Rich and High-Pressure

2014 ◽  
Vol 488-489 ◽  
pp. 786-789
Author(s):  
Yu Lin Zou
Keyword(s):  
Evaluation Method ◽  
Water Pressure ◽  
High Water ◽  
Western China ◽  
Effect Evaluation ◽  
Key Factors ◽  
Karst Tunnel ◽  
Pressure Water ◽  
Mixing Method ◽  
Specific Implementation

Based on a tunnel in western China as a project, with high water pressure, water-rich, karst features and other projects, launched grouting water research, the cement-silicate slurry mixing method for determining the mixing ratio to ensure the effectiveness and construction safety grouting key factors, as well as the specific implementation grouting effect evaluation method has important theoretical and practical value for the design and construction of similar tunnels provide a reference.

An Innovative Boiler Cleaning Method Using a Rotary Cable Swivel Tool

2004 ◽  
Author(s):  
Dominic Marra
Keyword(s):  
High Pressure ◽  
Water Pressure ◽  
Waste To Energy ◽  
New Method ◽  
Dade County ◽  
Water Delivery ◽  
Confined Space ◽  
Air Supply ◽  
Pressure Water ◽  
Full Face

The boiler generating bank (convective) sections of waste to energy boilers are commonly found to be very limited in regards to personnel access. The Miami-Dade County Resources Recovery Facility has had a challenge in the past to effectively clean this section of the boiler either on line or within a timely manner during outages. In 2003 the company used a new innovative method for cleaning this section off line. The boilers were 100% clean in 1/2 to 1/3 the usual time. The new method involved high-pressure industrial water blasting as typically used, with the exception of the water delivery device/system. Normally the water delivery method involves personnel placed in the boiler with hand held high-pressure water lances. They require confined space monitoring, lighting, scaffolding, proper air supply, frequent breaks, rain suits, full face shields and other PPE for safety inside the boiler. These factors combined with the limited space severely constrain the personnel and their effectiveness when using the water lances. Cleaning is compromised and has led to poor effectiveness and long duration cleanings. Explosives have also been tried to help augment cleaning. The new method used in 2003 involved no personnel in the boiler. Instead, for the water delivery system, a support cable is erected across the boiler upon which a rotary cable swivel tool (CST) is mounted. The tool has connections for high-pressure water and plant air and a simple winch for traversing the tool across the furnace. Very effective cleaning was accomplished from drum to drum, a distance of 20 feet (6.1 m). Depending on the application, the water pressure can be adjusted for maximum effectiveness. The air pressure is also adjusted to control the speed at which the rotary nozzles spin to best match the fouled conditions. The orientation and number of nozzles is also optimized for each application. This paper details the results of using the rotary Cable Swivel Tool (CST) in the generating bank section of the boilers and discusses related operational and maintenance benefits.

scholarly journals Experimental Study on Methane Desorption with the Coupling Effects of High Pressure Water and Thermal

2017 ◽  
Author(s):  
Dong Zhao ◽  
Dayuan Li ◽  
Yulin Ma ◽  
Zengchao Feng ◽  
Yangsheng Zhao
Keyword(s):  
High Pressure ◽  
Gas Flow ◽  
Water Pressure ◽  
Water Injection ◽  
Key Factors ◽  
Gas Desorption ◽  
Pressure Water ◽  
Methane Desorption ◽  
Injection Technology ◽  
Desorption Capacity

Moisture and thermal are the key factors for influencing methane desorption during CBM exploitation. Using high pressure water injection technology into coalbed, new fractures and pathways are formed to methane transport. It is existed a phenomenon of water inhibiting gas flow. This study is focused on various water pressures impacted on gas adsorbed coal samples, then the desorption capacity could be revealed under different conditions. And the results are shown that methane desorption capacity was decreased with water pressure increased at room temperature and the downtrend would be steady until water pressure was large enough. Heating could promote gas desorption capacity effectively, with the increasing of water injection pressures, the promotion of thermal on desorption became more obvious. There are the others effects on methane desorption capacity influenced by water injection and thermal.

Determination of Supply Pressure during Cutting Fish Using High-Pressure Water Stream Taking into Account the Cutting Place and Diameter of the Water Nozzle

2019 ◽  
Vol 16 (3) ◽  
Author(s):  
Maciej B. Kasperowicz ◽  
Grzegorz P. Chomka ◽  
Tadeusz Bil
Keyword(s):  
High Pressure ◽  
Muscle Flap ◽  
Processing Parameters ◽  
Water Jet ◽  
Raw Material ◽  
Spray Angle ◽  
Feed Speed ◽  
Water Stream ◽  
Supply Pressure ◽  
Pressure Water

AbstractThis work describes the research aimed at determining the value of the basic parameters of fish cutting on treatment with a high-pressure water jet. Assuming a constant feed speed, distance of the nozzle from the processed raw material, and spray angle of the water jet for six diameters of the water nozzles, the supply pressure value was determined. Supply pressure at which the water stream has enough energy to fully cut the muscle flap is also determined. The tests were carried out on samples obtained from rainbow trout, considering the size of the carcasses and the place of cutting. Analysis of the obtained results showed that both the size of the carcass and the cutting site affect the value of the supply pressure. However, regardless of this, the full cut of the lobe without the skin can be obtained by feeding the jet with a pressure of 3.5 MPa. This amount of pressure can easily be achieved using a Karcher pressure washer. To effectively apply this technology to the fish processing industry, it is necessary to extend the tests with further processing parameters such as the feed speed of the nozzle.

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