A calculation method for the average emitter operating pressure of drip irrigation

2012 ◽  
Vol 31 (4) ◽  
pp. 643-649 ◽  
Author(s):  
D. L. Zhu ◽  
P. T. Wu ◽  
J. Wang ◽  
L. Zhang
Keyword(s):  
Calculation Method ◽  
Drip Irrigation ◽  
Operating Pressure

Influence of operating pressure on emitter anti-clogging performance of drip irrigation system with high-sediment water

2019 ◽  
Vol 213 ◽  
pp. 174-184 ◽  
Author(s):  
Zeyuan Liu ◽  
Yang Xiao ◽  
Yunkai Li ◽  
Bo Zhou ◽  
Ji Feng ◽  
...  
Keyword(s):  
Drip Irrigation ◽  
Irrigation System ◽  
Operating Pressure ◽  
Drip Irrigation System ◽  
High Sediment

scholarly journals HYDRAULIC ANALYSIS OF DRIP LATERALS WITH INSIDE WELDED PRESSURE COMPENSATING DRIPPERS

2019 ◽  
pp. 575-580
Author(s):  
Dimitar Georgiev ◽  
Veselin Karasinkerov
Keyword(s):  
Flow Rate ◽  
Drip Irrigation ◽  
Elastic Membrane ◽  
Outer Diameter ◽  
Operating Pressure ◽  
Engineering Project ◽  
Head Losses ◽  
Horizontal Part ◽  
Distribution Uniformity ◽  
Inner Diameter

Lately, the drip irrigation systems built with pressure compensating (PC) drippers (emitters) inside welded in the drip laterals, find more and more application in Bulgaria, Turkey, Greece and other countries having well-developed irrigation-based agriculture, especially where the ground is not flat but rather is of hilly nature. The main advantage of these systems is the provision of uniform flow rate along the laterals and batteries (blocks) in the whole drip systems irrespectively of the alteration of the operating pressure, and, besides, this allows long laterals to be designed. The recommended operating pressure starts from 0.5 – 1.0 atm and reaches 4 – 5 atm. Reaching equal drip flow rate in these systems is realized thanks to an elastic membrane with fixed strength parameters, located at the outlet of the nozzles in a specially arranged bed (nest) for this purpose. The advertisement of the applications of those nozzles in the company catalogs is very intensive but is it true for all types of pressure compensating drippers? In laboratory conditions we carried out hydraulic tests of drip laterals with inside welded pressure compensating drippers, cylinder type, in order to find out the head losses along the drip lateral. The laterals were with a nominal outer diameter 16 mm, inner diameter 13.8 mm, thickness of the wall 1.1 mm and flow rate 2.1 l/h, at intervals of 33 cm between the drippers, with lengths 60, 80 and 100 m. The results showed considerable head losses, with great deviations from the ones obtained by analytic way through formulas. For example, in a 100 m long lateral, the losses reach 60 to 75% of the applied operating pressure at the beginning of the lateral. Some specific data from the tests – in case of inlet pressure of 18, 20 and 25 m, the head losses are respectively 12, 14 and 17 m which means that in case of flat ground and such with back slope it is almost impossible to realize a length of 100 m and more of the lateral. All drippers will not operate at the horizontal part of the curve “pressure-flow rate” but at the transitional part of this curve. It follows from this that irrespectively of the pressure compensating action of those nozzles, this type of laterals will hardly find application in real conditions in the design of an engineering project for drip irrigation respecting the admissible coefficients of the distribution uniformity of the irrigation water. The same is valid for the other tested laterals as well. Sometimes, laying conventional type of laterals is more appropriate and brings better results. All this is due to the considerable minor head losses in those nozzles because of the sizable constriction of the cross section of the laterals by the nest (bed) of the membrane.

scholarly journals PERDA DE CARGA EM FITAS GOTEJADORAS COM EMISSORES MOLDADOS

Irriga ◽  
2019 ◽  
Vol 1 (1) ◽  
pp. 86-93
Author(s):  
Verônica Gaspar Martins Leite de Melo ◽  
Leonardo Leite de Melo ◽  
José Antônio Frizzone ◽  
Antônio Pires de Camargo ◽  
Patricia Angélica Alves Marques
Keyword(s):  
Friction Factor ◽  
Drip Irrigation ◽  
Irrigation System ◽  
Low Cost ◽  
Pressure Head ◽  
Head Loss ◽  
Operating Pressure ◽  
Relative Errors ◽  
E Mail ◽  
Pipe Inlet

PERDA DE CARGA EM FITAS GOTEJADORAS COM EMISSORES MOLDADOS     VERÔNICA GASPAR MARTINS LEITE DE MELO1; LEONARDO LEITE DE MELO2; JOSÉ ANTÔNIO FRIZZONE3; antônio pires de camargo4 E patricia algélica alves marques5   1 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected] 2 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected] 3 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected] 4 Faculdade de Engenharia Agrícola – UNICAMP, Av. Cândido Rondon, 501, Cidade Universitária, CEP 13083 - 875, Campinas, SP, e-mail: [email protected] 5 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected]     1 RESUMO   Embora as fitas gotejadoras sejam de baixo custo, é importante que esse material seja avaliado hidraulicamente para prover informações técnicas. O objetivo deste trabalho foi analisar a perda contínua de carga e o fator de atrito em uma fita gotejadora com emissor moldado em seu interior. O experimento foi conduzido no laboratório de irrigação da ESALQ/USP. Utilizou-se a fita gotejadora Rain-Tape® fabricada pela Rain Bird®, espessura de parede de 225 µm e emissores tipo labirinto, espaçados de 0,30 m, vazão nominal de 1 L h-1 e pressão de serviço de 55 kPa. A equação de perda de carga para regime de escoamento turbulento liso em função da vazão e da carga de pressão na entrada da fita apresenta boa habilidade para estimar a perda de carga em fitas gotejadoras com emissores moldados, sendo que 95% das estimativas apresentaram erro relativo de até 6,71%. A equação de Darcy-Weisbach pode ser utilizada para o cálculo da perda de carga desde que o diâmetro seja substituído por uma função da pressão de entrada. Para o cálculo da perda de carga, utilizando a equação de Darcy-Weisbach, o fator de atrito calculado pela equação de Blasius deve considerar um coeficiente a = 0,3408.   Palavras-chave: irrigação por gotejamento, perda de carga por atrito, fator de atrito     MELO, V. G. M. L. de; MELO, L. M. de; FRIZZONE, J. A.; CAMARGO, A. P. de; MARQUES, P. A. A. HEAD LOSS IN DRIP TAPES WITH MOLDED EMITTERS     2 ABSTRACT   Although drip tapes are low-cost equipment, proper hydraulic evaluation is important to provide information required for irrigation system design. The aim of this study was to analyze the friction head loss and the friction factor in drip tapes with molded emitters, that are employed in drip irrigation systems. Experiments evaluated the drip tape model Rain-Tape®, manufactured by Rain Bird, 225-µm wall thickness, labyrinth-type emitters, 0.30-m emitters spacing, 1 L h-1 nominal discharge and operating pressure of 55 kPa. The following conclusions were obtained: (a) the equation of head loss for smooth turbulent flow as a function of flow rate and pressure head at the pipe inlet provided good predictions of head loss in drip tapes with molded emitters, since 95% of predictions presented relative errors less than 6.71%; (b) the Darcy-Weisbach equation may be used for calculating head loss, but the pipe diameter must be replaced by a function considering the lateral inlet pressure; (c) for calculating head loss of the Rain-Tape using the Darcy-Weisbach equation, the friction factor obtained by the Blasius equation should use the coefficient a = 0.3408.   Keywords: drip irrigation, frictional head loss, friction coefficient

scholarly journals Effect of pipe type and Emitters discharge on performance criteria of surface drip irrigation system

2021 ◽  
Vol 904 (1) ◽  
pp. 012013
Author(s):  
B A AL-Dulaimi ◽  
Sh M AL-Mehmdy
Keyword(s):  
Coefficient Of Variation ◽  
Drip Irrigation ◽  
Irrigation System ◽  
Performance Criteria ◽  
Research Station ◽  
Operating Pressure ◽  
Drip Irrigation System ◽  
Design Discharge ◽  
Distribution Uniformity ◽  
Surface Drip Irrigation

Abstract A field experiment was conducted in Jazeerah Al-Ramadi/Al-Hamidiyah research station (latitude33^o 27^’ 〖 11.9 〗 ^(՚՚)N, longitude 43^o 23^’ ^(՚՚) E (duration 2020. This study was conducted to investigate the effect of pipe types and emitters discharge on performance criteria of surface drip irrigation system. Therefore, a two factorial experiment was set as randomized complete block design with three replications. The first factor included the type of pipes and emitters, namely Turbo, GR and T-Tape. While the second factor involved the emitters discharge which consist of two levels i.e., 4 (D4) and 8 (D8) L.h-1. The irrigation system was initially evaluated in the field before planting by testing three operating pressures (50, 100 and 150 Kpa) to determine the actual discharge of the emitters closed to their design discharge (4 and 8 L.h-1) for each emitter to calculate the manufacturing coefficient of variation (CV), distribution uniformity and the discharge variation ratio at each operating pressure. Results showed that the best discharge (Closed to design discharge of 4 L.h-1) was obtained at the 50 Kpa operating pressure which gave 3.99,3.90 and 3.81 L.h-1 when using the T-Tape pipe and GR and Turbo emitter compare when the discharge of 8L.h-1 has been used which gave 7.96, 7.84 and 7.59 L.h-1 when the former pipe and emitters were used. The best coefficient of variation was observed when the T-Tape pipe and GR and Turbo emitter were used with discharge of 4 L.h-1 up to 0.1300, 0.2200 and 0.2600 compare to 0.1300, 0.2700 and 0.3500 when the same former pipe and emitters were used with discharge of 8L. h-1. Similarly, the best distribution uniformity was obtained when the T-Tape pipe and GR and Turbo emitter has been used with discharge of 4 L.h-1 which gave 94.68, 91.74 and 90%. Likewise, the most acceptable variety discharge ratio was observed when the same prior pipe and emitters were used with discharge of 4 L.h-1 by giving 7.23, 11.90 and 12.19 %.

scholarly journals Control of Tomato Pinworm (Tpw) with Abamectin in Staked Tomato, 1996

1997 ◽  
Vol 22 (1) ◽  
pp. 189-189
Author(s):  
P. A. Stansly ◽  
J. M. Conner
Keyword(s):  
Disease Control ◽  
Drip Irrigation ◽  
Rating Scale ◽  
Insect Damage ◽  
Operating Pressure ◽  
Hollow Cone ◽  
Commercial Plant ◽  
Entire Plant ◽  
Marketable Fruit ◽  
Tomato Pinworm

Abstract Tomato seedings “Agriset” from a commercial plant house were transplanted on 7 Mar 96, 18 in. between plants, into raised beds 32 in. wide on 6-ft centers covered with black polyethylene film mulch. A dry bottom mix of 50 lbs N, 160 lbs P and 80 lbs K per acre had been placed at the bottom of the beds and an additional 3.25 lbs per acre N and K were fertigated 3 times a week by drip irrigation. The plants were sprayed weekly with an alternating combination of Maneb 80 WP at 1.5 lb/acre plus Kocide 101 at 2 lb/acre and Bravo 720 at 2 pt/acre for disease control. Dipel was added to the disease control sprays when needed at a rate of 1 lb product/acre. Two wing-type traps from AgriSense containing TPW pheromones were set out on 23 Apr. 15 feet to the east and west of the trial area to monitor moth activity. Mean number of moths captured rose from 1.4 per night on 26 Apr to a peak of 33.6 on 10 May, later declining to 8.0 on 20 May. Plots, 30 ft long and 2 rows, wide were assigned one of 3 treatments in a CRB design with 4 replications. All treatments were sprayed weekly from 1 May to 15 May for three applications at 69 gpa using a high clearance sprayer with 2 booms of 3 Yellow Albuz hollow cone nozzles each for a total of 6 per row and operating pressure of 200 psi. Plants (10 per row or 20 total) were evaluated before treatment on 30 Apr and again on 6 and 13 May by counting live and dead miners. Damage for the entire plant was assessed on a rating scale of 1-6: “1” = no apparent damage; “2” = 0-1% of leaflets damaged; “3” = 2-5% damaged; “4” = 6-10% damaged; “5” = 11-30% damaged; and “6” = >30% damaged. Fruit was harvested 21 May from 20 plants per plot and the marketable fruit graded on a commercial table with weights and numbers recorded. Unmarketable fruit was separated into categories of TPW damage, other insect damage and damage due to disease.

scholarly journals A field study on hydraulic performance of drip irrigation system for optimization of operating pressure

2017 ◽  
Vol 9 (4) ◽  
pp. 2261-2263
Author(s):  
Mairaj Hussain ◽  
Sudhiranjan Prasad Gupta
Keyword(s):  
Field Experiment ◽  
Field Study ◽  
Coefficient Of Variation ◽  
Drip Irrigation ◽  
Irrigation System ◽  
Pressure Head ◽  
Maximum Efficiency ◽  
Operating Pressure ◽  
Drip Irrigation System ◽  
Irrigation Technology

Drip irrigation technology will undoubtedly plays an important role in the future of the agriculture. A field experiment was conducted to evaluate the performance of drip system with five operating pressure viz. I1 (0.4 kg/ cm2), I2 (0.6 kg/cm2), I3 (0.8 kg/cm2), I4 (1.0 kg/cm2), I5 (1.2 kg/cm2). It was observed that the average discharge of drippers was 1.08 lph, 1.24 lph, 1.50 lph, 1.62 lph and 1.74 lph and emission uniformity was 80.55%, 84.89%, 86.30%, 88.88% and 90.80 in each treatment respectively and coefficient of variation was observed 0.12, 0.13, 0.12, 0.11, and 0.09. Flow component was found 0.450 and the value of k was 0.572 while R2 was observed 0.986.Based on the result it can be concluded that the operation of drip irrigation system at 1.2 kg/cm2 pressure head, gives the maximum efficiency in respect of discharge, emission uniformity and coefficient of variation.

scholarly journals INVESTIGATION OF SOME PARAMETERS OF DRIP IRRIGATION BY HYDRAULIC EVALUATION OF DROPPERS

2019 ◽  
Vol 14 (2) ◽  
pp. 72-76 ◽  
Author(s):  
Ахмед Абделфаттах ◽  
Ahmed Abdelfattah ◽  
Борис Иванов ◽  
Boris Ivanov ◽  
Булат Зиганшин ◽  
...  
Keyword(s):  
Water Flow ◽  
Water Consumption ◽  
Drip Irrigation ◽  
Irrigation System ◽  
Type A ◽  
Operating Pressure ◽  
Laboratory Studies ◽  
Working Pressure ◽  
Main Pipe ◽  
Pressure Compensation

The results of laboratory studies of the proposed drip irrigation system are given. Five different types of droppers have been investigated to quantify the hydraulic characteristics. The dependences of the uniformity of water flow through droppers with a change in the working pressure in the system are obtained. Laboratory studies of the experimental facility were carried out at the training and demonstration center of Kazan State Agrarian University. The experimental installation consists of a storage tank, a submersible pump, five P.V.C. main pipes with a length of 3 m and a diameter of 16 mm, stop valves of a drip line, pressure gauges, a main stop valve, a collector line, a return line, and droppers. Before starting the experiments, air was removed from the system and pressure at the inlet to each main pipe was adjusted to the required value. Immediately under each drip, 500 ml volumetric containers were placed to determine the volume of leaked water in two minutes. Significant uniformity of water consumption and the smallest deviations from the specified nominal flow rate were achieved with type A and C droppers (with pressure compensation) at an operating pressure of 0.2 MPa; with type B droppers (also with pressure compensation), water flow uniformity decreased with increasing pressure. The results of the research show that pressure-compensated droppers are less sensitive to pressure changes with an operating pressure of 0.35 MPa. Water consumption (q) for type A droppers increased by 5.27%, B - by 27.3% and C - by 9.1%. Dropper type D and E have the lowest uniformity of water flow at different pressure levels. Under actual irrigation conditions, it is recommended to install pressure gauges not only in the collector line, but also on the main pipes (preferably at the end of each main pipe) to determine the differential and pressure losses in the system.

scholarly journals Study of the Hydraulic Performance Parameters of the Drip Irrigation System at Various Operating Pressures

2020 ◽  
Author(s):  
Parth J. Kapupara ◽  
Hina M. Bhatu ◽  
Jay Gohel
Keyword(s):  
Performance Evaluation ◽  
Drip Irrigation ◽  
Irrigation System ◽  
High Water ◽  
Hydraulic Performance ◽  
Operating Pressure ◽  
Drip Irrigation System ◽  
Uniformity Coefficient ◽  
Pressure Discharge ◽  
American Society

Background: Drip irrigation system is one of the best water application methods that have been used in the world among the other irrigation methods because of its upright and high uniformity and high-water use efficiency. Hydraulic performance evaluation is widely accepted for the evaluation of overall uniformity of a drip irrigation system. Methods: In an experimental study carried out at School of Engineering, RK University, Rajkot; hydraulic performance evaluation parameters viz., Pressure discharge relationship, Christiansen’s uniformity coefficient (CU), manufacturing coefficient of variation (CVm) and emission uniformity (EU) of non-pressure compensating emitters were calculated for 2 lph inline and 2 lph, 4 lph, 8 lph online emitter at various operating pressure of 0.8, 0.9, 1.0, 1.1 and 1.2 kg/cm2 as per American Society of Agricultural and Biological Engineers (ASAE) standards. Result: The study concluded that rated discharge of the emitter can be obtained at the operating pressure of 1.0 kg/cm2. Pressure discharge relationship revealed that discharge of the emitter upsurges as pressure rises. CU and EU were more than 95% for all the cases and they were maximum at 1.0 kg/cm2. CVm was less than 0.0200 for all the cases and it was minimum at 1.0 kg/cm2. Study concludes that all the parameter viz., CU, EU and CVm were excellent and very good categories for all emitters as per American Society of Agricultural and Biological Engineers (ASAE) standards.

scholarly journals Development and Evaluation of an Emitter with a Low-Pressure Drip-Irrigation System for Sustainable Eggplant Production

2019 ◽  
Vol 1 (3) ◽  
pp. 376-390 ◽  
Author(s):  
Sarker ◽  
Hossain ◽  
Murad ◽  
Biswas ◽  
Akter ◽  
...  
Keyword(s):  
South Asia ◽  
Water Use ◽  
Drip Irrigation ◽  
Crop Production ◽  
Irrigation System ◽  
Water Productivity ◽  
Low Pressure ◽  
Operating Pressure ◽  
Water Application ◽  
Sustainable Crop Production

Drip-irrigation can improve uniformity in water distribution, water use efficiency, and crop productivity in the saline and nonsaline regions of South Asia and in Bangladesh where the availability and quality of water resources are scare for sustainable crop production. However, the currently available drip-irrigation systems (DIS) have limitations especially in the design and field performance of emitters. A new type of emitter with low pressure (gravity) was developed, installed and evaluated using the locally produced materials in two locations (nonsaline and saline zones) of Bangladesh. The emitter discharge rate was measured for the variable operating heads of 1.5, 2, and 2.5 meter (m) with 0%, 1%, and 1.5% slopes with eggplant (Solanum melongena L.), a commonly grown vegetable in the region. The tested parameters of the emitter were manufacturer coefficient of variation (CVm), emission uniformity (EU), coefficient of uniformity (CU), and the statistical uniformity (Us) of water application. Our results reveal that the discharge rates of the emitter varied from 3 to 5 L h−1 under the operating head of 1.5 to 2.5 m with the slope of 0–1.5%, with better performance of the DIS at 2 m operating pressure head and for slopes of 0% and 1%. The CU of all the test parameters was more than 80%, implying that the DIS was designed and installed with appropriate dimensions for the efficient application and distribution of water to the individual plants, with the emitter performance classified as fair to excellent considering water application and distribution, as well as crop yield. The new emitter used for DIS in field conditions showed that the eggplant yield, water use, and water productivity were greater by 4.6%, 38%, and 70%, respectively, compared to farmers’ irrigation practice. We conclude that the DIS has a great prospect to save water, and could be a convenient irrigation water application method for sustainable crop production in saline and nonsaline regions of Bangladesh and similar soil and climatic conditions in South Asia.

scholarly journals Testing Novel New Drip Emitter with Variable Diameters for a Variable Rate Drip Irrigation

Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 87
Author(s):  
Hadi A. AL-agele ◽  
Lloyd Nackley ◽  
Chad Higgins
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Drip Irrigation ◽  
Water Flow Rate ◽  
Data Repository ◽  
Operating Pressure ◽  
Variable Rate ◽  
Water Losses ◽  
Full Field ◽  
Outside Diameter

This research presents a new variable rate drip irrigation (VRDI) emitter design that can monitor individual water drops. Conventional drip systems cannot monitor the individual water flow rate per emitter. Application uniformity for conventional drip emitters can be decreased by clogged emitters, irregular emitter orifices, and decreases in pressure. A VRDI emitter can overcome the irrigation challenges in the field by increasing water application uniformity for each plant and reducing water losses. Flow rate is affected by the diameter of the delivery pipe and the pressure of the irrigation delivery system. This study compares the volumetric water flow rate for conventional drip emitters and new VRDI emitters with variable diameters inner (1 mm, 1.2 mm, 1.4 mm, and 1.6 mm) and outside (3 mm, 3.5 mm, 4 mm, and 4.5 mm) with three pressures (34 kPa, 69 kPa, and 103 kPa). The tests revealed that the new VRDI emitter had flow rates that increased as the operating pressure increased similar to a conventional drip tube. The flow rate was slightly increased in the VRDI with pressure, but even this increase did not show large changes in the flow rate. The flow rate of the conventional drip tube was 88% larger than the VRDI emitter for all pressures (p < 0.05). However, operating pressure did not affect the drop sizes at the VRDI emitter, but the generalized linear mixed models (GLM) results show that volume per drop was impacted by the outside diameter of the VRDI outlet (p < 0.05). The interaction between the inner and outside diameter was also significant at p < 0.01, and the interaction between outside diameter and pressure was statistically significant at p < 0.01. The electronic components used to control our VRDI emitter are readily compatible with off-the-shelf data telemetry solutions; thus, each emitter could be controlled remotely and relay data to a centralized data repository or decision-maker, and a plurality of these emitters could be used to enable full-field scale VRDI.

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