Manufacturing Variation and Drip Irrigation Uniformity

Bralts, Vincent F.; Wu, I-Pai; Gitlin, Harris M.

doi:10.13031/2013.34209

Cited by 99 publications

(6 citation statements)

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“…There were minor changes in the values of the proportionality coefficient (K) and in the flow exponent (x) as a function of variations in water temperature. According to Bralts et al (1981), the K coefficient factors are relative to the construction of the emitter and thus, the variations due to manufacturing would be embedded in the value of K. The factors inherent to the flow behavior are expressed by the flow exponent (x). The K and x coefficients were statistically significant (p ≤ 0.05) for all cases presented in Table 2.…”

Section: Resultsmentioning

confidence: 99%

Discharge sensitivity of collapsible drip tapes to water temperature

Frizzone

Camargo

Pereira

et al. 2021

Rev. bras. eng. agríc. ambient.

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The objective of this study was to quantify the effect of water temperature variations on the discharge of collapsible thin-walled drip tapes with integrated non-pressure-compensating emitters. The tests were conducted in the laboratory using an automated test bench. Tests were performed to determine the discharge-pressure curves by varying the water temperature from 20 to 50 °C. Nine emitter models of three wall thicknesses (6, 8, and 9 MIL) were evaluated. The coefficients K and x of the discharge-pressure curves varied according to the water temperature. In flat emitters of turbulent flow (x < 0.5), the discharge decreased as the temperature increased. In the welded emitters of turbulent flow, several responses were observed. Regarding emitter D (x > 0.5), the discharge increased as the temperature was increased, while for emitter C (x < 0.5), the discharge decreased; the highest discharge variations occurred at pressures higher than 60 kPa. For embossed emitters, the discharge increased as a function of temperature, however, the greatest variation occurred at the lowest pressures. None of the emitters showed significant difference in the discharge variation due to wall thicknesses.

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Section: Resultsmentioning

confidence: 99%

Discharge sensitivity of collapsible drip tapes to water temperature

Frizzone

Camargo

Pereira

et al. 2021

Rev. bras. eng. agríc. ambient.

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“…where CV f ield is the measured coefficient of flow variation in the field due to all factors, CV hyd is the flow variation due to hydraulic pressure variations, CV clog is the flow variation due to clogging, and the three sources of variation are assumed to be uncorrelated [23,35]. Assuming that all emitters are operating above their MCIPs and clogging is negligible, the last two terms under the square root would be zero and uniformity would be a function of CV m only.…”

Section: Uniformity and Cloggingmentioning

confidence: 99%

Energy Reduction and Uniformity of Low-Pressure Online Drip Irrigation Emitters in Field Tests

Sokol

Amrose

Nangia³

et al. 2019

Water

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A promising way of addressing the issue of growing water scarcity is through wider use of drip irrigation, which delivers water and fertilizer to crops in a slow, targeted manner, and has been shown to increase yields and water use efficiency. Yet, drip irrigation system adoption is low, primarily due to the high capital cost of the pressurized piping network and the pump, and operating energy cost. Lowering the water pressure needed for drip emitters to deliver water can reduce both capital and operating costs of drip systems. Here we present the results from field trials of new pressure-compensating online drip emitters that operate with a minimum compensating inlet pressure of 15 kPa (0.15 bar), in comparison to typical commercial emitters with minimum pressures of 50–100 kPa (0.5–1.0 bar). The field trials were carried out on nine farms in Morocco and Jordan over the course of one irrigation season with freshwater and treated wastewater. Low-pressure emitters are shown to reduce hydraulic energy per unit volume of water delivered by 43% on average compared to commercial emitters, without significantly sacrificing water emission uniformity (low-pressure emitters show uniformities of 81–91%, compared to 87–96% for commercial emitters). This energy reduction could lead to savings of 22–31% in the capital cost of a pump and emitters and the energy cost for a typical drip irrigation system. Thus, the low-pressure online emitters can be used as substitutes to commercial emitters that require higher water pressures, leading to reduced environmental impact and lower system costs.

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“…In addition, the emitter manufacturing variation coefficient, which affects hydraulic design, was suggested by several researchers (Anyoji & Wu, 1987;Bralts et al, 1981) and was also used as an alternative Pi term, but it was not possible to enter this dimensionless term into the model in prior statistical analysis. The model given in Eq. (3) as a theoretical form can be expressed as follows with exponential terms: …”

Section: The Simplified Prediction Modelmentioning

confidence: 99%

“…The authors considered that the inlet pressure head to a lateral line was a maximum and that the pressure head at the downstream end was a minimum. Bralts, Wu, and Gitlin (1981) derived an equation to statistically combine the effects of pressure variations and emitter manufacturing variation on the flow rate of every emitter. The overall system uniformity affected by hydraulic design, manufacturing variation and plugging was evaluated statistically.…”

Section: Introductionmentioning

confidence: 99%