Showing 6 results for Emitter
J. Abedi Koupai, A. Bakhtiarifar,
Volume 8, Issue 3 (10-2004)
Abstract
Water crisis is an important issue in arid and semi-arid regions like Iran. The situation has been getting more worse over recent years drought. Hence, there is a growing need to utilize low quality water where freshwater is scarce. In this regard, urban wastewater is a promising source but there are concerns about the environmental and health aspects of using such water. The main problem regarding the performance of trickle irrigation system utilizing wastewater effluents is clogging of the emitters. In this study, field trials at pilot scale were carried out to investigate the hydraulic properties of emitters using two types of water including treated wastewater and groundwater. The trickle irrigation system consisted of three 16 mm lateral tubes placed at 300 mm spacing in the main tube and each lateral tube had 16 emitters at 300-mm spacing. The designed discharge of the emitters was 4 L/h. The hydraulic properties of the different commercial emitters (micro flapper, long path, turbo plus and Eurokey) were assessed at different time periods.
The results indicated that the Eurokey and long path emitters had the maximum and minimum emission uniformity, respectively, when applying wastewater. using groundwater, the Eurokey and turbo plus emitters had the maximum and minimum emission uniformity, respectively, during the initial phase of the study. However, the Eurokey and long path emitters had the maximum and minimum uniformity values, respectively, at the end of the study. The turbo plus emitters are regulated and, as a result, showed no evidence of sensitivity to pressure variations hence, they can be used on uneven lands and where the trickle irrigation system has long lateral tubes.
A. H Nasrolahi, M. Behzad, S. Bromand Nasab, M. Heydariniya,
Volume 17, Issue 66 (2-2014)
Abstract
Drip irrigation is a new method of irrigation that is rapidly growing in different countries. The emitters are the most important parts of a drip irrigation system. Many factors such as physical, chemical and biological clogging, pressure, water temperature affect the emitter´s uniformity of water emission. In this study, to investigate pressure effect on the hydraulic performance of emitters, 7 kinds of compensating emitters in the market were selected and studied in laboratory conditions. For this purpose, a drip irrigation system was designed in irrigation laboratory in faculty of water sciences engineering, Shahid Charm University, Ahwaz. Average flow of emitters, Manufacturer´s coefficient of variation of emitter(CV), emission uniformity(EU), Christiansen coefficient of uniformity(CU) and Flow Variations for all types of emitters at pressures of 5, 10, 15 and 20 meters were calculated and compared. Also, in order to compare the pressure compensating capacity, for every emitter the equation of Flow- pressure was extracted. Results showed that the D-type emitter has the best hydraulic performance from among the emitters tested. Therefore, to achieve higher efficiency and also to use it on slopes and uneven lands this emitter is recommended as the best. However, performances of other emitters are also acceptable.
E. Maroufpoor, M. Parvini,
Volume 17, Issue 66 (2-2014)
Abstract
One of the most important issues in trickle irrigation design is investigating the emitter's characteristics, the effect of factors on flow rate, and finally appropriate emitter selection. Therefore, in this study nine types of pressure compensating emitters with codes of A, B, C, D, E, F, G, M and N, made based on trickle irrigation physical model were tested and the effects of four different water temperatures (13, 23, 33 and 43°C) with different pressure ranges (between zero and 1.2 times more than the maximum pressure) on the emitters were evaluated. All experiments were carried out based on ISO 9261 standard and IRISI 6775 standard of the Institute of Standards & Industrial Research of Iran. The obtained results at all the tested temperatures, no emitter has x more than 0.2 and all emitters were pressure compensating types. The effect of temperature on the flow rates of models F, M and N was significant at 95% confidence level. Increase in temperature showed an increase in the flow rates of the above mentioned models.
F. Mohamadzade, M. Gheysari, E. Landi,
Volume 19, Issue 71 (6-2015)
Abstract
The objectives of this study were to investigate the effect of dripper discharge and irrigation time on the wetted width in the sandy loam soil with high percentage of gravel and to evaluate previously developed models of estimation of the wetted width in the previous researches. The treatments included three irrigation times (T) of 4, 8 and 12 h and three dripper discharge rates (q) of 2, 4 and 8 l/h, with three replications. The wetted width of each dripper was measured 24 hours after irrigation application. The maximum and minimum wetted widths were 159.8 and 63.5 cm for T12q8 and T4q2, respectively. A linear model was developed as a function of two variables of irrigation time and dripper discharge rate was developed to predict the wetted width in sandy loam soil with high percentage of gravel. The evaluation of recommended models of wetted width for the studied soil showed that only one of six models was accurate enough to estimate wetted width. It can be concluded that the presence of gravels in the soil has a complex effect on width and depth of wetted zone. Thus, it is necessary to measure the wetted width and wetted depth in the field.
C. Abdi, P. Fathi,
Volume 21, Issue 3 (11-2017)
Abstract
Drip irrigation is one of the new irrigation methods for optimum use of water resources and increase of irrigation efficiency. The emitters' clogging is the most important problem in these systems. The physical clogging is the most important factor in reducing the discharge and emission uniformity of emitters. The emitter position on the laterals and emitter spacing are the factors that affect the physical clogging rate of emitters. The objective of the present study is evaluating the effect of emitter spacing of drip irrigation tape on the physical clogging rate of emitters. For this purpose, a physical model of drip irrigation tape was designed and made at the laboratory. In this research, seamless and seamed irrigation tapes with emitter spacing equal to 10, 20 and 30 centimeters were used. Statistical analysis showed that emitters spacing have significant effect on clogging rate of emitters in seamless and seamed drip irrigation tapes. The results also indicated that seamless irrigation tapes with 30-centimeter emitters spacing, with clogging rate of 22 percent, have the least clogging. A comparison of clogging rate and uniformity coefficient of irrigation tape showed the higher performance of seamless irrigation tape in clogging condition.
H. Dabbaghi, M. Khoshravesh, M. A. Gholami Sefidkouhi,
Volume 22, Issue 2 (9-2018)
Abstract
Emitter clogging for using agricultural wastewater increases the operating costs and reduces the motivation of farmers. The new method to reduce the emitters clogging is the use of a Merus ring that does not have the problems of chlorination and pickling methods, such as pollution and high cost. Due to the importance of agricultural wastewater use, this study investigated the emitters clogging and the effect of Merus ring on the emitter's efficiency in a trickle irrigation system. The treatments including irrigation water (well water and wastewater) and modified water (irrigation with Merus ring and irrigation without Merus ring), as the main factor and the emitters type treatment including Irritec (D1), Corona (D2), Axios (D3), Netafim (D4), Polirood (D5), and Paya (D6) as the sub treatments were performed in three replications. The results showed that the agricultural wastewater caused the emitters clogging in irrigation water and modified water treatments, but over time, the Merus ring had a positive effect on the evaluation parameters of the emitters. For agricultural wastewater, in the first and last irrigation periods, the average discharge of emitters with the Merus ring was 0.05 and 0.33 Liter per hours, respectively, more than the treatment without the Merus ring. The uniformity coefficient of emitters in the first and last irrigation periods, in well water with the Merus ring, was 0.31%and 6.67%, respectively, more than that in the well water without the Merus ring. Also, the uniformity coefficient of emitters in the first and last irrigation periods in agricultural wastewater with the Merus ring was 0.85% and 12.10%, respectively, more than that in agricultural wastewater without the Merus ring. At the end of irrigation period, the results showed that Netafim and Axios had the best and weakest efficiency, respectively. In general, the emitters used in the treatment of well water with the Merus ring had the highest discharge and the emitters used in the treatment of wastewater without the Merus ring had the lowest discharge.
