Jet Washing Research Articles

An Improved Positive Displacement Pump Model Accounting for Suction Cavitation

Abstract Positive displacement (PD) pumps are widely employed in industrial settings due to their inherent simplicity and reliability, serving a variety of applications from slurry transport to jet washing. Although their operational principles are straightforward, the fluid dynamics of the pumped medium exhibit nontrivial characteristics, including intricate transient phenomena. Consequently, a comprehensive fluid dynamic description, such as a three-dimensional fluid analysis, presents challenges due to its demanding computational requirements. While simpler analytical PD pump models are available, they often fail to adequately represent the primary system behaviors, particularly when dealing with cavitation. Motivated by these challenges, this study aims to develop a novel one-dimensional model for PD pumps, offering a representation of essential fluid phenomena without imposing significant computational burdens. After assessing the relative importance of the fluid dynamic behaviors that the model must capture, we construct a pump model based on a one-dimensional fluid description and solve it using a second-order in time and space monotone upwind scheme for conservative law and total variation diminishing (MUSCL-TVD) scheme. The model's validity is confirmed by its application to both single-chamber and three-chamber diaphragm PD pumps, which are instrumented for experimental validation. The results of the one-dimensional model exhibit strong agreement with physical experiments, both in controlled laboratory environments and field conditions. This success suggests a promising approach for industrial applications.

Assessing Worker and Pedestrian Exposure to Pollutant Emissions from Sidewalk Cleaning: A Comparative Analysis of Blowing and Jet Washing Techniques

Sidewalk cleaning operations are essential to maintaining a clean and safe urban environment. Despite their vital role, these activities, particularly the blowing of road dust, can lead to the resuspension of road dust and associated pollutants, which poses risks to human health and the environment. While the role of blowers on particulate matter resuspension has been investigated, there is limited information on emitted bioaerosols. This study aimed to compare the occupational exposure of operators and passersby during sidewalk cleaning using two manual methods—blowing and jet washing—in two distinct urban environments. The study focused on metal road traffic tracers (copper (Cu), zinc (Zn), manganese (Mn), cadmium (Cd), and lead (Pb)) and cultivable/non-cultivable microorganisms. We showed that blowing resuspends inhalable particles containing metals (Cu, Zn, and Mn, but not Cd or Pb) and bioaerosols (fungi and Gram-negative bacteria) throughout the year. This represents an important source of exposure for the blower operators and poses a potential long-term respiratory health risk for them. Operators working in cabs are shielded from such exposure, but passersby, especially vulnerable populations, may be at risk. While jet washing reduces operator exposure to Gram-negative bacteria in comparison to blowing, it does not mitigate fungal exposure, particularly in vegetated sites. These findings underscore the necessity for the implementation of effective protective measures and the development of alternative cleaning methods to mitigate exposure risks.

КОМПЛЕКСНАЯ МОДЕРНИЗАЦИЯ ЭЛЕКТРОПРИВОДА ПРИ ОРГАНИЗАЦИИ РЕМОНТНЫХ РАБОТ ТРУБОПРОВОДНЫХ СИСТЕМКОМПЛЕКСНАЯ МОДЕРНИЗАЦИЯ ЭЛЕКТРОПРИВОДА ПРИ ОРГАНИЗАЦИИ РЕМОНТНЫХ РАБОТ ТРУБОПРОВОДНЫХ СИСТЕМ

The issues of organizing repair work on field pipeline systems during the production of liquid hydrocarbons are considered. The influence of the quality of washing of contaminated parts on repair operations was determined. Measures have been proposed to improve the efficiency of jet washing machines. To expand the functionality, it is proposed to introduce into the design an adjustable electric drive for rotating the washing basket. This will allow you to optimize the rota-tion speed in relation to the specifics of the part and the level of contamination

Influence of the Duration of the Jet Wash on the Degree of Parts Cleaning

The influence of the washing process duration on the degree of cleaning of automotive equipment parts during jet washing has been studied. It has been experimentally proven that increasing the washing time to 5 minutes increases the degree of purification to 83.35 %. Its further increase does not lead to significant improvement.

Safe and effective methods for mining thin tilt and steeply dipping deposits with ore drawing via mud flow

For mining of thin (1–3m) tilt (15–45°) ore bodies, it is recommended to use the mining method with induced mud–water–stone flows to deliver broken ore up-dip the bodies in combination with scraper handling of ore along the strike and water jet washing of ore when forming columnar pillars, including underhand ore cutting, with division of blocks into many long stopes along the block strike, heading of one or two tilted accumulation and haulage rooms to be close-looped with the long stopes, scraping of broken ore to the tilt accumulation and haulage rooms and mud flow of ore along these rooms. This method can increase the stoping capacity as per the number of stopes in a block: for example, in a 160 m wide, only two tilt rooms are required to be headed between levels. The artificial mud flows in mining (or re-mining) of thin and steeply dipping ore bodies which have their girtwise bottom boundary skewed at 15–45 °, are no less effective. For the purpose of mining (re-mining) of such reserves, it is proposed to use a process flowsheet as follows: broken ore flows under gravity to the lower part of the extraction block and, then, along the tilted bottom of the block, it goes down under the action of gravity and energy of water flow in the mode of the mud–water–stone flow to the ore intake room on this level. In this case, as against mechanical haulage, the mud flow of broken ore essentially enhances the ore production output owing to the high capacity of the mud flow, and greatly reduces the scope of the preparatory and actual mining operations connected with the block bottom formation.The study was supported in the framework of the Target Financing Program of the Ministry of Education and Science of the Republic of Kazakhstan, Program No. 2018/ВR05236712.

Applicability of neutral electrolyzed water for cleaning contaminated fixed orthodontic appliances

We investigated whether water jet washing with neutral electrolyzed water (NW) can be an easy and safe self-performed cleaning method for oral environments of fixed orthodontic appliance-wearing patients. In line with this, we examined the bactericidal effects and dissolution behaviors of metal elements released from appliances. A metal or resin bracket ligated with a metal wire and metal bracket adhered to an apatite-pellet were used as specimens. The bacteria and plaque removal effects of the 30 seconds of NW (30, 100 ppm) jet washing for contaminated specimens were examined via an agar-plate method and the observation of the residual plaque, comparing with other treatments (brushing and flow washing), those treatments with tap water (TW), and flow washings with commercial mouthwashes, Listerine Total Care+ (LS) and ConCool F (CC). The amounts of metal released from metal specimens during the 1-week immersion in NW were analyzed and compared with those in TW, LS, and CC. NW jet washing produced larger decreases of surviving bacteria than the treatments with TW and CC (P<0.05) and equal or larger decreases than the treatment with LS (P<0.05). NW jet washing yielded the highest plaque removal level. The amounts of nickel and chromium released from metal specimens after the 1-week immersion in NW (30 ppm) were less than or equal to those with LS. NW jet washing could be applicable for cleaning fixed orthodontic appliances because of its higher bactericidal effects than the treatments with commercial mouthwashes, inducing no or a slight metal release in actual usage time.

Municipal Waste Disposal Strategy by Fuzzy TOPSIS Method

Municipal solid waste is a major challenge for the metropolitan city. Improper handling of municipal solid waste will create the city unsuitable for living.in this paper, we are discussing about the Indore Municipal Corporation strategy to make the city, one of the cleanest city in India. For this purpose, the 5 selected methods are assigned ranks using Fuzzy TOPSIS method by taking opinion from decision makers and averaged for further analysis. On the basis of reviews 6 main problems created in the city due to municipal waste management ( Dust, Fouling, Emission level, Spreading of Diseases, Open defecation ad Improper segregation) are taken into considerations and 20 decision maker’s opinion is taken on measures taken by Indore municipal corporation for reducing problems created in the city due to municipal waste management are Abolishing cattle, Making more number of urinals, D2D garbage collection, General public awareness, Mechanized road sweeping n jet washing and Using twin bins for source segregation. In this paper the Evaluation shows that open defecations ranking one among all the problems which is greatly reduced by various measures taken by the Indore municipal corporation followed by spreading of disease and improper segregation.

Analysis of washing modes of metal tin cans outer surface in jet-type washing machines

The main parameters of jet washing of cans are: the concentration of the alkaline solution and its temperature, the pressure of the solution at the nozzle, the shape and dimensions of the nozzle opening, the angle of the direction of the jet toward the surface being cleaned, the distance from the water jet nozzle to the surface of the washable cans. The study of these parameters was carried out on a special experimental setup equipped with instrumentation. Dependence of washing efficiency on solution ressure given to the cap with different diameters of its holes was found. Furthermore, it is established that the process efficiency decreases with increase of pressure for more than 3 kg/cm2, as a certain hydrodynamic mode of jet percussion action begins at the boundary with the surface being cleaned. Cleaned surface becomes larger with increase of concentration and temperature of washing solution. Increase of solution concentration for more than 3% and its temperature for more than 70÷75°C do not promote intensification of the process. Cleaned surface depends on angle of jet direction at the point of its strike with the can surface. This dependence represents the fact that the cap should be placed in relation to transported cans in such a way that the jet would be always at right angle to the dirty surface.

Trajectory Generation for Water Jet Washing by Pig House Cleaning Robot

Trajectory Generation for Water Jet Washing by Pig House Cleaning Robot

Improvement of the zygote utilization and reduction of the seedling loss in the early stage of seedling production of Sargassum thunbergii (Fucales, Phaeophyta)

Artificial seedling production of Sargassum thunbergii is an effective way to relieve pressure on natural resources. In order to improve the utilization of zygotes and reduce the loss of seedlings, studies on the characteristic of the zygotes release, the development of rhizoids, the attachment of germlings, and the influence of jet washing were conducted. Results show that the percent of zygotes released was increased with time in the first 60 h. The capacity of germlings attached to the substratum was significantly increased, especially coincident with the time of the new rhizoids emerged and elongated. The detachment rate of germlings significantly decreased with the delay of starting time of jet washing or the reduction of jet washing velocity. However, the jet washing at any level applied in the experiment could cause considerable loss of germlings within the 20 days after the attachment. Our study provided some parameters to optimize the operation in the early stage of seedling production.

지연제 살포량과 물씻기 시간이 골재노출 콘크리트의 표면성상에 미치는 영향

지연제 살포량과 물씻기 시간이 골재노출 콘크리트의 표면성상에 미치는 영향

S0510303 Couette流れと干渉する衝突噴流の熱伝達に関する研究

Impinging jet is widely used in industrial fields, such as thermal management of electronic devices or jet washing. In addition, we can see many both of numerical and experimental studies on interfering flows between mainstream or Hagen-Poiseuille and impinging jet. These kinds of flows are well appearing at T-shape merging pipe flows or film cooling on turbine blades. However, there are few studies on heat transfer field interfering Couette flow and impinging jet, in spite of typical flow such as cooling rotary inner-cylinder of bearing, cooling rolled steel in its production process and carrier gas flow of Additive Manufacturing (A.M.). Especially for industrial using of A.M., it becomes a huge obstacle due to its much complicated multi-physical mechanism between the moving grinding table and the jet including carrier gas and additive particle. Therefore, we have studied numerically on the heat transfer of impinging jet interfering with Couette flow, and compared with several different jet inlet angles. In this study, we used DNS which employing secondary conservative second order central difference scheme for convective terms of Navier-Stokes equations and heat transport equation to obtain unsteady flow and temperature scalar fields. Then, we confirmed this DNS results agree qualitatively with those of Quasi-DNS which had been done in our former studies.

0610 水中ウォータージェット洗浄装置の最新動向

0610 水中ウォータージェット洗浄装置の最新動向

Effect of thermal treatment on the bending strength of glass ceramic/resin cement

Objectives: To investigate the effect of the thermal treatment on the bending strength of ceramic bars (VM7) treated by the cementation protocol. Material and Methods: Forty ceramic bars (20 x 4 x 1.2 mm) were constructed and randomly distributed into 2 groups (n=20): NT - without treatment/control and T – with treatment (50°C above the glass transition temperature, for 15 min). All specimens underwent the cementation process in which one surface of the ceramic bar was etched (20 s) with 10% hydrofluoridric acid, followed by air-water jet washing (60 s), drying (30 s), silane agent application and resin cementation. After storage (distilled water/seven days at 37 ºC), the specimens were submitted to 3-point flexure test at 100% humidity/37 ºC (v=1 mm/min, load cell of 10 kgf). Results: The bending strength values and standard deviations (MPa) were: NT: 19.98 (3.17)a; T: 20.45 (4.67)a (one-way ANOVA and Tukey test, ?=0.05). Conclusions: The thermal treatment did not influence on the bending strength mean values of the ceramics studied.

Zygote-derived seedling production of Sargassum thunbergii: focus on two frequently experienced constraints in tank culture of seaweed

Mass collection of germlings and growth of fouling algae are two main constraints for the seedling production of Sargassum thunbergii. In this study, 65% and 40% of reproductive output (allocation of biomass to sexual reproductive tissue) for farmed and natural populations respectively, were recorded during peak reproduction. In terms of germlings per kilogram wet weight of plants, the farmed population gave a higher yield than the natural population (3.2 × 105 and 1.2 × 105 germlings kg-1, respectively). These results indicate that farmed populations could be used as parental plants for germling collection in seedling production. During the experiment, fouling was controlled by jet washing and high-density seeding. A germling detachment of less than 10% was observed when, after 48 h of attachment, collectors were jet-washed with an intensity of 1 kg cm-2. High-density seeding had adverse effects on length mean, size equality, and occurrence of branches of germlings. However, 30–50 individuals cm-2 are thought to be usable in the seedling production of S. thunbergii because of less density effects. Seedlings of > 0.5 cm length could be achieved after 1 month of tank culture.

Laboratory screening of coating libraries for algal adhesion

Coatings libraries achieved through a combinatorial chemistry approach, which may generate tens to hundreds of formulations, can be deposited in an array of 12 patches, each approximately 9 cm2, on 10 × 20 cm primed aluminum panels. However, existing methods to quantify algal biomass on coatings are unsuitable for this type of array format. This paper describes an algorithm modelled on a probability distribution that quantifies the area of surface covered by a green alga from digital images. The method allows coatings with potential fouling-release properties to be down-selected for further evaluation. The use of the algorithm is illustrated by a set of eight siloxane-polyurethane coatings made using organofunctional poly(dimethylsiloxane) (PDMS) and poly(ϵ-caprolactone)-PDMS-poly(ϵ-caprolactone) (PCL-PDMS-PCL) triblock copolymers along with four PDMS standards which were deposited on one panel. Six replicate panels were seeded with Ulva zoospores which grew into sporelings (small plants) that completely covered the surface. The ease of removal of the Ulva sporeling biofilms was determined by automated water jetting at six different impact pressures. The coverage of the biofilm on the twelve individual formulations after jet washing was quantified from the green colour of digital images. The data are discussed in relation to the composition of the coatings.

管路施設の維持管理システムについて―老朽排水管のスパイラル・ジェット洗浄，管路のホースライニング工法など―

管路施設の維持管理システムについて―老朽排水管のスパイラル・ジェット洗浄，管路のホースライニング工法など―

An Assessment of the Microbiological Risks Involved with Egg Washing under Commercial Conditions

The potential benefits of washing eggs is offset by a historical perception in the European Union that wetted eggs are prone to spoilage and water loss. This study describes the effects of spray jet washing under various processing conditions to shell surface counts ofSalmonella and the presence of bacteria in egg contents. Experiments used eggs that were contaminated withSalmonella Enteritidis PT4 orSalmonella Typhimurium DT104 before cuticle hardening. Washing of contaminated eggs under optimum conditions resulted in a more than 5-log reduction ofSalmonella counts from the shell surface.Salmonella was not isolated from the yolk or albumen of any egg washed by the optimal protocol, suggesting that when properly controlled, egg washing did not causeSalmonella to enter the contents. However, contamination did arise if strict control was not maintained over the wash and rinse water temperatures. BothSalmonella Enteritidis andSalmonella Typhimurium were shown to enter the egg contents when water temperatures were lowered, indicating that strict temperature control must be maintained in order to prevent the ingress ofSalmonella into egg contents. Other washing machine parameters that were investigated did not significantly affectSalmonella entry into the egg contents but influenced shell surface kill levels to varying degrees.

Stirring up Trouble? Resuspension of Bottom Sediments by Recreational Watercraft

ABSTRACT An experimental and theoretical study of the hydrodynamic impacts of recreational watercraft in shallow water bodies is presented. Of particular interest is the ability of turbulent prop or jet wash to resuspend bottom sediments. Intuition suggests, and the experiments confirm, that this ability is a strong function of boat speed and water depth. The results of this study demonstrate that boats operating at high speed have no greater impact on the lake bed than boats travelling at idle speeds. The greatest impact is seen when boats are travelling at ‘near-plane’ speeds. This critical speed is a function of boat size and water depth. To increase the usefulness of the observations, a theoretical model of the flow underneath a passing boat was developed and validated with the data. Relying on only a few input parameters, the model can be used to estimate, for example, the minimum operating depth required for a given boat to prevent sediment resuspension. Discussion of the relevance of this work in the context of setting use restrictions for watercraft is provided.

The influence of three methods of gravel cleaning on brown trout, Salmo trutta , egg survival

Siltation of spawning gravels in upland rivers appears to be an increasing hindrance to salmonids' spawning success. River managers seek an effective and non-labour intensive means of loosening gravel and reducing fine material, so improving spawning success; this study compared three practical gravel cleaning techniques, applied at realistic (rather than intensive) levels, by assessing survival to hatching of buried brown trout, Salmo trutta L., ova at five sites on four rivers with gravel substrate in southern England. Each site consisted of six reaches, of which three were cleaned by tractor rotovating, high pressure jet washing and pump washing; these were compared with adjacent, untreated reaches. Brown trout ova were buried in both fine mesh and coarse mesh boxes in each reach. Significant improvements (at P<0·05) in survival (number of live alevins) were found in three of the five pump washed reaches, two of the five tractor rotovated reaches and one pressure washed reach when the data were analysed by site. When data from all five sites were analysed together, all treated reaches showed a significant improvement (at P<0·05) in egg survival to hatching compared with control reaches for fine mesh egg boxes; for coarse mesh boxes only pump washed reaches showed such an improvement. We feel that pump-washing provides the most effective, inexpensive and suitably non labour-intensive means of improving gravel, although ultimately it may be better to reduce the silt load of rivers. Freeze core bed samples taken before and immediately after cleaning were analysed for silt content; pump washing and high pressure washing may have reduced the amount of fine material. Copyright © 1999 John Wiley & Sons, Ltd.