Sprinkler Head Research Articles

IMPROVING THE PERFORMANCE OF MICRO SPRINKLERS IRRIGATION BY REDUCING ITS RANDOM MOTION

Limited fresh water resources become a serious issue worldwide particularly arid and semi-arid conditions. Therefore more efficient irrigation systems are fundamentally required to increase water productivity. Micro sprinklers are among these new systems to maximize irrigation efficiency. Random motion of micro sprinklers head reduces the uniformity of water. This study aimed to improve water distribution efficiency of micro sprinklers by reducing its random motion. The study investigated the effects of operating pressure, sprinkler height on the performance of micro sprinklers before and after modification. Irrigation system was operated at four different levels of operating pressure (150, 180, 220 and 250 kPa) and three different sprinkler heights of 0.5, 1.0 and 1.5 m. Water distribution efficiency was evaluated through the calculation of Christiansen’s uniformity coefficient (CCU) and distribution uniformity (DU). The highest CCU and DU values of 91.8% and 86% were recorded with 250 kPa operating pressure, and 1.5 m sprinkler height when using copper support followed by same conditions when using PVC tubes. Therefore, sprinklers without support produced less water distribution efficiency in comparison to cases of copper and PVC tubes. The results thus revealed that water distribution efficiency can be maximized through reducing random motion of sprinkler head and choosing the optimum operating conditions (e.g. operating pressure and sprinkler height).

Transfer of Escherichia coliO157:H7 from Simulated Wildlife Scat onto Romaine Lettuce during Foliar Irrigation

A field trial in Salinas Valley, California, was conducted during July 2011 to quantify the microbial load that transfers from wildlife feces onto nearby lettuce during foliar irrigation. Romaine lettuce was grown using standard commercial practices and irrigated using an impact sprinkler design. Five grams of rabbit feces was spiked with 1.29 × 108CFU of Escherichia coliO157:H7 and placed − 3, − 2, and − 1 days and immediately before a 2-h irrigation event. Immediately after irrigation, 168 heads of lettuce ranging from ca. 23 to 69 cm (from 9 to 27 in.) from the fecal deposits were collected, and the concentration of E. coliO157:H7 was determined. Thirty-eight percent of the collected lettuce heads had detectable E. coliO157:H7, ranging from 1 MPN to 2.30 × 105MPN per head and a mean concentration of 7.37 × 103MPN per head. Based on this weighted arithmetic mean concentration of 7.37 × 103MPN of bacteria per positive head, only 0.00573% of the original 5 g of scat with its mean load of 1.29 × 108CFU was transferred to the positive heads of lettuce. Bacterial contamination was limited to the outer leaves of lettuce. In addition, factors associated with the transfer of E. coliO157:H7 from scat to lettuce were distance between the scat and lettuce, age of scat before irrigation, and mean distance between scat and the irrigation sprinkler heads. This study quantified the transfer coefficient between scat and adjacent heads of lettuce as a function of irrigation. The data can be used to populate a quantitative produce risk assessment model for E. coliO157:H7 in romaine lettuce to inform risk management and food safety policies.

Capacity Evaluation of Suspended Ceiling Components, Part 2: Analytical Studies

The seismic performance of a ceiling system is difficult to analytically predict due to its heterogeneous and complex details. On the other hand, lack of experimentally based analytical models for ceiling components results in over-simplified analytical models. Therefore, this second of two companion papers minimizes the gap between the complexity of ceiling systems and the weakness of previous analytical works by increasing modeling capabilities. To do so, 32 component-level analytical models are generated based on monotonic and cyclic tests of the ceiling wires, ceiling panels, and grid connections. These models are developed to capture the axial behavior of ceiling wires, the interaction between ceiling panels and sprinkler heads, and the shear and bending behavior of grid connections in both local axes. This research promotes a pathway to conduct analytical simulations of ceiling systems in conjunction with the structures.

Deformation Analysis of Assembly Load on Fire Extinguishing Sprinkler Head

The necessity about the installation of fire extinguishing sprinkler system came to the fore as fire accidents are increased for small-scale building. For this reason, it is making an effort to simplify the sprinkler system, and it becomes necessary to redesign a conventional sprinkler head. However, the numerical analysis of a sprinkler head has not been found in the literature. Meanwhile, a fusible alloy which is used as an operation switch of sprinkler head is weak in strength, and a force which needs to assemble the sprinkler head is also added to the internal parts including the fusible alloy. Futhermore, it is also difficult to analyze only through experimental method, because the sprinkler head which is structurally complex is composed of various parts. So far, it takes a long time to develop a reliable sprinkler head due to trial and error in experiment. Accordingly, in order to redesign or optimize the sprinkler head efficiently, it needs to observe the internal changes while assembling parts. Therefore, the aim of this study is to build the analytical model of a reliable conventional sprinkler head. Meanwhile, inner and outer loading plates are deformed by the force in the assembly process, and their deformations are used as a standard for building a model of sprinkler head. In this respect, the design method based on the deformation analysis by using FEM is used in this paper. Additionally, it needs to investigate the stress of FM for improving the stability of sprinkler head. Thus, the deformation and stress distributions are described visually and numerically by the simulation results which are not able to be evaluated by experiment.

국내 랙크식 창고의 방화관련 규정 개선에 관한 연구

최근 발생한 아모레퍼시픽 창고화재는 국내 랙크식 창고의 자동식소화설비 및 감지기 설치기준의 보완 및 개선의 필요성을 제시하고 있다. 물류창고는 보관물품에 따라 화재 확산율 및 열 방출비율이 다르며 저장높이, 랙크 배치, 통로폭, 물품의 양 등에 따라서 화재위험성이 결정된다. 고천정화에 따른 화재하중의 증가로 인하여 자동식 스프링클러설비가 작동하여도 가연물에 직접적인 침투효과에 한계가 있으며 화재감지기의 작동시간이 지연되어 초기소화에 실패할 확률이 높아진다. 이를 위하여 본 연구에서는 화재사례 및 국내외 관련규정비교 그리고 현장조사 등을 수행하여 랙크식 창고의 초기소화 및 제어성능을 확보하기 위한 수용물품의 위험도 분류 및 스프링클러 설치기준 개선방향과 화재피해를 최소화하기 위한 제도적 도입을 제안한다. Recently Amore pacific rack-type warehouse fire broke out and argue an urgent improvement of fire protection design code including automatic sprinkler and detection design. Various type of commodities have their unique fire characteristics from fire spread rate and heat lease rate and fire hazard depends on storage height, rack arrangement, aisle width, fire load etc. With increasing ceiling height for more storage space prevent effective water spray of sprinkler head, also delays detection time causes failure of early suppression. To achieve fire protection code performance of this occupancy, Major code articles relating to a classification of commodity, sprinkler system installation, detection and fire fighting are reviewed and suggested based on fire case analysis, code review between country and field survey.

Design of FDM Rapid Prototyping System

Fused Deposition Modeling is a widely used rapid prototyping technology; Filamentous molten materials are heated into fusion in heating cavity, and then squeezed out through the nozzle of sprinkler head. Under the control of the computer, the nozzle moves according to the information that CAD plane determined, extruding the molten materials and solidifying into parts at the same time. Almost any complex shape parts can be produced, and this technology has the advantage of high utilization of raw material and easy removal of support material.

Experimental Seismic Fragility of Pressurized Fire Suppression Sprinkler Piping Joints

Pressurized fire suppression sprinkler piping is a critical nonstructural system that must remain operational after an earthquake, particularly in critical facilities. Observations from past earthquakes have demonstrated that the locations most susceptible to damage in sprinkler piping systems are the joints, sprinkler heads, support hangers, and bracing systems. However, field observations and previous experimentations are insufficient to fully characterize the response of sprinkler piping systems under seismic actions and to develop effective solutions to improve their performance. This paper presents the results of an experimental program designed to evaluate the seismic behavior of sprinkler piping joints. Forty-eight tee joints made of various materials (black iron with threaded joints, thermoplastic (CPVC) with cement joints, and steel with groove-fit connections) and nominal diameters (¾ in. to 6 in.) were tested under reverse cyclic loading to determine their rotational capacities at which leakage and/or fracture occur. The ATC-58 framework is applied to develop a seismic fragility database for pressurized fire suppression sprinkler joints considering joint rotation as the demand parameter. Fragility functions in terms of more global demand parameters, such as floor accelerations, can be developed using data presented here combined with structural analysis models of sprinkler piping systems.

Alpine grassland ecosystem respiration variation under irrigation in Northern Tibet

Grassland ecosystems are important parts of terrestrial ecosystems and play an important role in the global carbon cycle. In recent years, the grasslands in Northern Tibet have experienced warming, and its precipitation has also increased. Alpine grassland irrigation measures could be a reasonable pathway to redistribute and make full use of the increased precipitation. In this study, we measured the soil respiration in alpine grassland in Northern Tibet under sprinkler head irrigation in the growing season to determine the relationships between soil temperature /water and ecosystem/soil respiration, soil moisture and Q10, and soil temperature and Q10. The results showed that after 2 years irrigation, alpine grassland aboveground biomass increased significantly, with 2010 higher than 2009. There was significant annual, seasonal and daily variation of soil respiration. Under irrigation, ecosystem respiration and soil respiration increased 75% and 64% respectively; soil water increase can promote the respiration of ecosystem and its components. In our results, the Q10 value was 2.23–2.81, over the global average. The irrigation can promote ecosystem respiration temperature sensitivity. There was a positive linear correlation between ecosystem respiration and grassland aboveground biomass. The aboveground biomass accounted for 32.8% of ecosystem respiration variation. Soil respiration accounted for more than 70% of ecosystem respiration, indicating that the contribution to carbon emissions of soil respiration is very high. In short, we can project that in grasslands biomass and ecosystem respiration will increase under future precipitation change, which will significantly affect the function of alpine grassland carbon storage.

An experimental study on the spray characteristics of residential sprinklers under low-flow and low-pressure conditions

An experimental investigation to explore the characteristics of the initial drop screen which was formed by sprinkler heads at low water pressures was carried out. Two commercially available sprinkler heads (with thin and massive frame arms) were modified, not only in terms of deflector plate design, but also with respect to the orifice diameter, in order to decrease the flow and study the effect on liquid sheet thickness, initial sheet angle, sheet breakup distance and drop size distributions and their correspondence with the existing mathematical models. It was found that the addition of a boss in the sprinkler design had little impact on the average drop size and sheet breakup distance. The presence of the boss was found to influence the initial angle of the liquid sheet, which was in line with findings of previous researches. Longer slots on the deflector plate did not change the initial angle of the sheet considerably, but did result in an earlier sheet breakup and smaller median drop diameter.A drop combustion sub-model was built, introducing two novel parameters: theoretical heat capacity (THC) and evaporate heat capacity (EHC), which could be used for estimating the actual heat capacity of the spray. In combination with the calculated drop size distribution in a spray screen, the combustion sub-model confirmed that sprinkler performance does not depend merely on provided flow, but rather on the drop size and the number of drops in a drop screen.

스프링클러 작동시 분무액적이 연기거동에 미치는 영향에 관한 연구

본 연구는 성능적인 피난안전설계에 있어서 스프링클러를 응용한 설계를 위하여 스모크로깅현상에 대한 연기층 하강기류에 대해 고찰하였다. 이를 위해 PIV(particle image velocimetry)장비를 이용하여, 국내 스프링클러 헤드별 분무액적특성을 실험적으로 고찰하고, 화원의 크기 및 스프링클러 헤드의 종류에 따른 연기층의 하강기류를 분석하였다. 그 결과, 평균입경, 입자속도, 살수분포에 관한 데이터를 얻었으며, 살수량과 입경과의 관계를 얻었다. 또한 하강기류에 관하여, 하강기류속도가 0.6 m/s이 되면 연기층이 하부층으로 이동하는 것을 확인하였으며, 100 kW 이상의 화원크기가 존재하여야 안정적인 하강기류가 발생하는 것을 확인하였다. This study contemplated the descending air current from the smoke layers related to the smoke logging phenomenon in the sprinkler applied design for effective evacuation safety design. To do this, using the PIV(Particle Image Velocimetry) device, the property of watering spray for each sprinkler head types available in Korea were experimented and the descending air current from smoke layers for each size of fire source or the type of sprinkler head was analyzed. As a result, database on the average particle diameter, particle velocity and distribution of sprinkling was obtained and the relationship between the water amount and particle diameter was obtained. Also, in relation to descending air current, the movement of smoke layer to the bottom at the descending air current velocity of 0.6m/s was observed and stable descending air current was observed in existence of fire source over 100kW in size.

Taking the Lead with Disposable ECG Leads: Preventing Chest Incision Surgical Site Infections

METHODS: A faulty fire sprinkler head failed resulting in the flooding of the sterile supply for a 120 bed hospital. Responding personal set up fans to facilitate drying, adding to the contamination. This study evaluates the efficacy of combining pulsed xenon disinfection with routine terminal cleaning protocols following a flood. Quick recovery efforts prevented the collection of environmental samples before the terminal cleaning. Twenty environmental swab samples were collected after a routine terminal cleaning. The pulsed xenon machine ran for one 15 minute disinfection cycle on each side of the sterile supply room. Afterwards, 20 additional cultures were collected. RESULTS: The Group 1 (pre-pulsed xenon disinfection) culture samples grew a combined total of 10 colony forming units (CFU) (5 Staphylococcus spp., 2 Bacillus non-anthracis spp., 3 Coagulasenegative Staphylococcus), while the Group 2 (post-pulsed xenon disinfection) culture samples grew 1 CFU (Streptococcus viridans) after 48 hours. Utilizing a paired t-test to compare the data sets resulted in a two-tailed P value of 0.0158 with a 95% confidence interval of 0.09 to 0.81. Group 1 had a mean of 0.50 with a standard deviation of 0.69, and Group 2 resulted in a mean of 0.05 with a standard deviation of 0.22. CONCLUSIONS: The Results of this study illustrate that by combining pulsed xenon disinfection and terminal cleaning procedures; we were able to achieve a statistically significant reduction in CFUs on environmental surfaces and supplies. Through this study we were able to demonstrate that successful disinfection of surfaces following an environmental disaster was achievable by using pulsed xenon UV technology. Also, because discarding the non-compromised supplies was not necessary, saving the facility more than $150,000 in sutures alone, we were able to demonstrate the cost effectiveness of this technology.

A Free-Surface Model of a Jet Impinging On a Sprinkler Head

Understanding the atomization of fire sprinkler sprays fills a critical gap in the modeling of fire suppression systems. Previous research by the authors has shown an instability model coupled with a stochastic transport model can paint most of the sprinkler spray picture, but requires input in the form of thickness and velocity of unstable fluid sheets. The model outlined describes a water jet impinging on a perforated deflector plate as a velocity potential. The free surface separating the jet from the surrounding air takes the form of a vortex sheet with the air assumed to be at rest. Through the use of the Green’s function, the fluid velocity potential can be posed as a boundary value problem. Any solution obtained is an exact solution to the inviscid flow equations and the interior flow a solution to the Navier-Stokes equations. The resulting model allows for the determination of the complete flow field over a sprinkler head of arbitrary geometry and input conditions. Knowledge of this flow field provides insight into the impact of sprinkler head geometry and fluid velocity as well as providing the above mentioned inputs for a complete model of fire sprinkler sprays.

Movable Surface Irrigation SystemDesign

Center pivot modification depends on replacing the sprinkler head (sprayer) by polyethylene hoses ending by nozzles. Field experiments were conducted at the experimental farm of Faculty of Agriculture, in Shams University, to modify sprinkler pivot to work as a moving surface irrigation system. Two different nozzles shapes were selected (trapezoid and triangle) with two different hoses length (25 and 200 cm). Pilot area was divided into two halves, the first was straight furrow, while the second was furrow as well as concentrated with track of pivot wheel, and planted maize. The main objectives of this study are to modify pivot irrigation system to be more suitable to irrigate trees, and other crops under special conditions, to evaluate the modification system and to reduce the investment costs of the modified system. Results show that, operating the Movable Surface Irrigation System.(MSIS) at low pressure head (1.5 bar), water amount was decreased by (16.8%), the uniformity coefficient for triangle form was 91.6%,pulled hoses (200cm) were better than the short hoses, on the other hand, water use efficiency (WUE) with Movable Surface Irrigation System. system was (2.5 kg/m 3 ) while it was (1.84 kg/m 3 ) with sprinkler pivot system and the Movable Surface Irrigation System. system reduced the hazard of chemigation. The investment cost of the modified system was reduced as compared with traditional system with little energy required for the Movable Surface Irrigation System. system. There's no significant difference between the two methods of furrow on grain yield of maize.

Reliability of sprinkler system in Australian high rise office buildings

A comprehensive survey of sprinkler systems in high-rise office buildings was carried out to determine the reliability of various components of such systems in Australia. Based on the survey data, a fault tree analysis (FTA) has been used to estimate the overall reliability of these sprinkler systems. Data from 26 buildings were collected and are presented in this paper. In addition, data from overseas surveys has also been considered based on their relevance to the office buildings. The analyses are confined only to wet-pipe systems, as these constitute the vast majority of automatic sprinkler systems in Australia and New Zealand. To develop the fault trees, the designs found in usual practice are considered, rather than the designs just complying the Australian codes with the minimum requirements. A range of reliability for the sprinkler systems is estimated based on a number of considerations. Sprinkler zone shut off during tenancy changes and out of specification sprinkler head appear to be the main factors that may lead to a sprinkler system failure.

스프링클러설비 화재안전기준 개정에 대한 고찰

스프링클러설비의 화재안전기준 중 불합리한 것에 대하여 개정할 것을 제안을 하였다. 배관의 용어 중 "수평주행배관"의 용어정의를 추가하도록 하였으며 "격자형배관방식"에 대한 정의를 수정하도록 제안하였다. 스프링클러헤드의 소화수 방출압력을 규정한 조항을 합리적으로 운영하기 위하여 NFPA 13의 스케줄방식의 최소 유량과 압력기준을 확인하였고 이와 유사한 최소 요구량 기준을 제정할 것을 제안하였다. 압력수조의 평상 시 유지 압력 산출식을 바르게 개정할 것을 제시하였으며 압력단위의 변화에 의한 올바른 K값의 사용을 제시하였고 기존의 K값 등을 사용하기 위하여 압력단위를 [bar]를 사용할 것을 제안하였다. This paper suggested to revise unreasonable national fire safety codes of sprinkler system. Also proposed to modify the definition of "the gridded sprinkler system" and to add "the feed main" in terms of the definition of the pipes. In order to operate the regulations of discharge pressure of the sprinkler head efficiently, this paper checked the minimum criteria of pressure and flow for the pipe schedule sprinkler system of NFPA 13 and suggested to establish the similar minimum demand criteria. It proposed to be amended properly the pressure calculation formular in the pressure tank system and to use the correct K value due to change in pressure unit and to use the [bar] as a unit of pressure for the sake of using the existing K-factor etc.

Discussion of “Effect of Sprinkler Head Geometrical Parameters on Hydraulic Performance of Fluidic Sprinkler” by Xingye Zhu, Shouqi Yuan, and Junping Liu

Discussion of “Effect of Sprinkler Head Geometrical Parameters on Hydraulic Performance of Fluidic Sprinkler” by Xingye Zhu, Shouqi Yuan, and Junping Liu

Closure to “Effect of Sprinkler Head Geometrical Parameters on Hydraulic Performance of Fluidic Sprinkler” by Xingye Zhu, Shouqi Yuan, and Junping Liu

Closure to “Effect of Sprinkler Head Geometrical Parameters on Hydraulic Performance of Fluidic Sprinkler” by Xingye Zhu, Shouqi Yuan, and Junping Liu

Analysis on Practical Thermal Responsiveness of the Glass Bulb Sprinklers

In Taiwan, qualified glass bulb sprinklers must be validated by the Approval Criteria for Close Sprinkler Head. However, the actuation temperature marked on the sprinkler head is the temperature as tested in water, not the ordinary air temperature In the actual scene of the fire. The difference in the thermal conductivity between water and air is 23 times. This study uses heat transfer principles for derivation and FDS software for a thermal responsiveness analysis of glass bulb sprinklers. Fire loads of 0.5, 1.5 and 2.5 MW are simulated with both ultra-fast and slow burning rates; the cracking temperature of the glass bulb and the hot air velocity are recorded. The results show that there are significant differences in actuation and detecting environment when the sprinklers head contact the hot air at the fire scene. The marked detection result can only serve as a qualification because of the differences in fluid properties. In addition, the actuation time of the sprinkler head is closely related to the burning rate.

318 スプリンクラーヘッドの最適設計に関する基礎研究 : ヒュージブルリンクの動作特性について

318 スプリンクラーヘッドの最適設計に関する基礎研究 : ヒュージブルリンクの動作特性について

Color Gamut of UV Wide-Format Inkjet Printing on Special Substrates

UV Inkjet Printing has demonstrated extraordinary potential in printing technology around the globe in recent years. Other than its environment-friendly trait, UV Inkjet Printing can also be applied to various printing materials due to its wide range of application. Comparing to the low-price competition invoked by paper-based printing, it achieves high added-value results from its output. While international market’s perspective on inkjet printing remains positive, most printing press in Taiwan still have doubts for the technology. In recent years, there has been a considerable growth in importing UV Width Inkjet printers in Taiwan domestically. However, working personnel in Taiwan are inexperienced in dealing with new equipment and wider selection of printing materials, therefore the issue of printers adapting to their diverse printing materials. This study will examine the five combinations of UV printer and printing materials that are common in Taiwan (brands of printers, serial number of the sprinkler head, and brands of printing ink) and three specific high-value printing substrates (glass, acrylic and melamine plywood). Through the printing experiment, the color gamut of printing materials will be re-examined. The goal of the study is to establish a standard for UV printing’s application in decoration materials, so as to provide reference for future development.