scholarly journals DESEMPENHO DE GOTEJADORES OPERANDO COM ÁGUA RESIDUÁRIA DE LATICÍNIOS EM ESCALA LABORATORIAL

Irriga ◽  
2018 ◽  
Vol 21 (1) ◽  
pp. 140 ◽  
Author(s):  
Blake Charles Diniz Marques ◽  
Vanessa Tainara da Cunha ◽  
Valéria Tatiany da Cunha ◽  
Ketson Bruno da Silva ◽  
Rafael Oliveira Batista
Keyword(s):  
Flow Rate ◽  
Operating Time ◽  
Dairy Wastewater ◽  
Semiarid Region ◽  
Uniformity Coefficient ◽  
Microbiological Characteristics ◽  
Wastewater Quality ◽  
Distribution Uniformity ◽  
Experimental Trials ◽  
Iron Manganese

DESEMPENHO DE GOTEJADORES OPERANDO COM ÁGUA RESIDUÁRIA DE LATICÍNIOS EM ESCALA LABORATORIAL  BLAKE CHARLES DINIZ MARQUES1; VANESSA TAINARA DA CUNHA1; VALÉRIA TATIANY DA CUNHA1; KETSON BRUNO DA SILVA1; RAFAEL OLIVEIRA BATISTA1 1 Departamento de Ciências Ambientais e Tecnológicas, UFERSA câmpus Mossoró-RN, Avenida Francisco Mota, no 572, Bairro Costa e Silva, CEP: 59.625-900 - Mossoró, RN, Brasil. E-mail: [email protected], [email protected], [email protected], [email protected], [email protected]  1 RESUMO A degradação ambiental e a escassez hídrica no semiárido são fatores que contribuem para utilização de águas residuárias na agricultura. A irrigação localizada torna-se o método mais adequado para este fim, devido ao uso eficiente da água. Neste contexto, o presente trabalho teve por objetivo monitorar a vazão e o coeficiente de uniformidade de distribuição (CUD) em unidades de irrigação, dotadas de cinco tipos de gotejadores (G1 = 1,6 L h-1, G2 = 2,0 L h-1, G3 = 2,0 L h-1, G4 = 1,70 L h-1 e G5 = 2,0 L h-1) aplicando água residuária de laticínios; e avaliar as características físico-químicas e microbiológica do efluente, quanto ao risco de obstrução. O monitoramento da qualidade da água residuária de laticínios foi realizado a cada 40 h, simultaneamente com a determinação da vazão dos gotejadores e do CUD, totalizando seis amostragens, até o encerramento dos ensaios experimentais, no tempo de operação de 200 h. O gotejador G2 foi o mais suscetível ao entupimento com efluente de laticínios tratado, enquanto o gotejador G5 foi o mais resistente ao entupimento. As características sólidos suspensos, sólidos dissolvidos, ferro, manganês, cálcio e a presença de microrganismos, interferiram, diretamente nos valores da vazão dos gotejadores e do CUD das unidades de irrigação que operaram com efluente de laticínios tratado. Palavras-chave: emissores, efluente, obstrução.  MARQUES, B. C. D.; CUNHA, V. T.; CUNHA, V. T.; SILVA, K. B.; BATISTA, R. O.DRIPPERS PERFORMANCE OPERATING WITH DAIRY WASTEWATER IN LABORATORY SCALE  2 ABSTRACT Environmental degradation and water scarcity in the semiarid region are factors that contribute to the use of wastewater in agriculture. This study aimed to monitor the flow rate and the distribution uniformity coefficient (CUD) of irrigation units in five types of drippers (G1 = 1.6 L h-1, G2 = 2.0 L h-1, G3 = 2.0 L h-1, G4 = 1.70 L h-1 and G5 = 2.0 L h-1) applying wastewater dairy, as well as the physicochemical and microbiological characteristics of the effluent, that represented risk of obstruction. Monitoring of the dairy wastewater quality was performed every 40 h, simultaneously with the determination of the emitter flow rate and CUD, totaling six samples until the end of the experimental trials, in 200 h of operating time. The dripper G2 was the most susceptible to clogging with treated dairy wastewater, while the drip G5 was the most resistant to clogging. Solid suspended, dissolved solids, iron, manganese, calcium and presence of microorganisms interfered directly on flow rate and CUD of irrigation units that operated with treated dairy effluent. Keywords: emitters, effluent, clogging. 

scholarly journals Water Distribution Uniformity in Driping System Under Growing Pressures

2019 ◽  
Vol 7 (11) ◽  
pp. 14-21
Author(s):  
JHONATAN PIAZENTIN ◽  
João Luis Zocoler ◽  
Camila Pires Cremasco ◽  
Alfredo Bonini Neto ◽  
Luís Roberto Almeida Gabriel Filho
Keyword(s):  
Flow Rate ◽  
Water Distribution ◽  
High Efficiency ◽  
Environmental Cost ◽  
Agricultural Systems ◽  
Uniformity Coefficient ◽  
Number Of Factors ◽  
Cost Reductions ◽  
Use Efficiency ◽  
Distribution Uniformity

Increasing water use efficiency in agricultural systems is critical as it results in economic and environmental cost reductions, especially in localized irrigation, which depends on a number of factors, especially the flow rate of the emitters and proper uniformity of water distribution, both with respect to direct with the pressure of the emitters For this evaluation the use of coefficients of water uniformity, it is essential to indicate the best wetness management. The experiment was carried out in the Irrigation laboratory, in a test stand, using Christiansen uniformity coefficient - CUC, distribution uniformity coefficient - CUD and statistical uniformity coefficient - CUE. In the irrigation line, four pressures on the drip emitter (5, 10, 15 and 20 mca) were applied. The pressure variations obtained did not reduce the efficiency of the uniformity of water distribution by the drip system, falling into high efficiency ranges for all evaluated coefficients, representing adequate wetting rates.

scholarly journals UNIFORMIDADE DA DISTRIBUIÇÃO DE EFLUENTE EM UNIDADES GOTEJADORAS APLICANDO DILUIÇÕES DA ÁGUA RESIDUÁRIA DE LATICÍNIOS

Irriga ◽  
2018 ◽  
Vol 23 (3) ◽  
pp. 592-608
Author(s):  
Blake Charles Diniz Marques ◽  
Rafael Oliveira Batista ◽  
Rodrigo Cesar Santiago ◽  
Jeane Cruz Portela ◽  
Maria Elidayane da Cunha ◽  
...  
Keyword(s):  
Operating Time ◽  
Dairy Wastewater ◽  
Dairy Effluent ◽  
Waste Reuse ◽  
Two Factors ◽  
Distribution Uniformity ◽  
Chemical Attributes ◽  
Set Up ◽  
E Mail

UNIFORMIDADE DA DISTRIBUIÇÃO DE EFLUENTE EM UNIDADES GOTEJADORAS APLICANDO DILUIÇÕES DA ÁGUA RESIDUÁRIA DE LATICÍNIOS¹     BLAKE CHARLES DINIZ MARQUES2; RAFAEL OLIVEIRA BATISTA2; RODRIGO CÉSAR SANTIAGO2; JEANE CRUZ PORTELA2; MARIA ELIDAYANE DA CUNHA2 E RUTILENE RODRIGUES DA CUNHA2   1  Trabalho oriundo da Tese de Doutorado do primeiro autor. 2 Universidade Federal Rural do Semi-Árido, UFERSA câmpus Mossoró, Departamento de Engenharia e Ciências Ambientais, Avenida Francisco Mota, n° 572, Presidente Costa e Silva, 59625-90, Mossoró, RN, Brasil. E-mail: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]     1 RESUMO   O entupimento de emissores é a principal vulnerabilidade dos sistemas de irrigação localizada que operam com águas residuárias. Com este estudo identificaram-se os agentes ocasionadores de obstrução de gotejadores que operaram com diluições de efluente de laticínios (EL) em água de abastecimento público (AA), bem como as alterações na uniformidade de distribuição de efluente (CUD) das unidades gotejadores. Para a avaliação do CUD durante 200 h, montou-se um experimento com dois fatores, sendo o primeiro fator, os cinco tipos de gotejadores (G1 - 1,6 L h-1, G2 - 2,0 L h-1, G3 - 2,0 L h-1, G4 - 1,70 L h-1 e G5 - 1,60 L h-1), casualizados nas subunidades gotejadoras; e o segundo fator, as quatro diluições de EL em AA (1A0E - Apenas AA; 1A1E - Uma parte de EL diluída em uma parte de AA; 2A1E - Uma parte de EL diluída em duas partes de AA; e 3A1E - Uma parte de EL diluída em três partes de AA), casualizados nas unidades gotejadoras. O monitoramento da qualidade do efluente diluído ocorreu a cada 40 h, simultaneamente com a determinação do CUD das unidades gotejadoras, até o tempo de operação de 200 h. Os resultados indicaram que o risco de obstrução do efluente diluído variou de moderado a severo em relação aos atributos físico-químicos; que a maior suscetibilidade ao entupimento ocorreu no gotejador G2, operando nas diluições 1A1E e 3A1E, enquanto o gotejador G5 se mostrou menos suscetível ao entupimento operando na diluição 2A1E.   Palavras-chave: resíduo industrial, reuso, desempenho, emissores.     MARQUES, B. C. D.; BATISTA, R. O.; SANTIAGO, R. C.; PORTELA, J. C.; CUNHA, M. E.; CUNHA, R. R. EFFLUENT DISTRIBUTION UNIFORMITY IN DRIP UNITS BY APPLYING DAIRY WASTEWATER DILUTIONS     2 ABSTRACT   Emitter clogging is the main vulnerability of localized irrigation systems that operate with wastewater. This study identified drip obstructing agents that operate with dairy effluent dilutions (DE) in public water supply (WS), as well as alterations in effluent distribution uniformity (DU) of drip units. To assess DU over 200 h an experiment with two factors was set up, the first factor is the five types of drippers (G1 – 1.6 L h-1, G2 – 2.0 L h-1, G3 – 2.0 L h-1, G4 – 1.70 L h-1 and G5 – 1.6 L h-1), randomized in the drip subunits; and the second factor, the four dilutions of DE in WS (1A0E – WS only; 1A1E – A portion of DE diluted in a part of WS; 2A1E – A portion of DE diluted in two parts of WS; and 3A1E – A portion of DE diluted in three parts of WS), randomized in the drip units. The monitoring of the dairy effluent dilutions quality occurred every 40 h, simultaneously with the determination of the DU of the drip units until the operating time of 200 h. The results indicated that the risk of obstruction of the diluted effluent varied from moderate to severe in relation to the physical-chemical attributes; that the greatest susceptibility to clogging occurred in G2 dripper, operating with 1A1E and 3A1E dilutions, while G5 dripper was less susceptible to clogging in 2A1E dilution.   Keywords: industrial waste, reuse, performance, emitters.

scholarly journals Effect of Pulsating Pressure on Water Distribution and Application Uniformity for Sprinkler Irrigation on Sloping Land

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 913 ◽  
Author(s):  
Lin Zhang ◽  
Boyang Fu ◽  
Naiwang Ren ◽  
Yu Huang
Keyword(s):  
Distribution Pattern ◽  
Flow Rate ◽  
Complex Terrain ◽  
Water Distribution ◽  
Constant Pressure ◽  
Sprinkler Irrigation ◽  
Water Application ◽  
Uniformity Coefficient ◽  
Sloping Land ◽  
Distribution Uniformity

Crops are highly susceptible to drought in sloping land. Due to its good adaptability to complex terrain, sprinkler irrigation is one of the commonly used methods for sloping land. To improve water application uniformity for sprinkler irrigation on sloping land, an experiment was conducted on an artificial slope to determine the effects of pulsating versus constant pressure on sprinkler flow rate, radius of throw, water distribution pattern, and water application uniformity. Compared with sprinkler flow rate and water distribution uniformity at constant pressure, sprinkler flow rate was not reduced, but water distribution uniformity for a single sprinkler was improved due to the decreased uphill throw, downhill throw and the ratio of downhill throw to uphill throw at pulsating pressure. The Christiansen Uniformity Coefficient (CU) value of water distribution for a single sprinkler at pulsating pressure was about 10% higher than that of constant pressure. When water distribution of single sprinkler overlapped with rectangular arrangement, CU values for pulsating pressure were on average 4.06% higher than those for constant pressure with different sprinkler spacings. Thus, pulsating pressure is recommended for use in sprinkler irrigation on sloping land to improve water application uniformity.

scholarly journals AVALIAÇÃO DA UNIFORMIDADE DE APLICAÇÃO DE ÁGUA EM GOTEJADORES EM FUNÇÃO DO TEOR DE FERRO

Irriga ◽  
2011 ◽  
Vol 16 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Rigléia Lima Brauer ◽  
Raimundo Leite Cruz ◽  
Roberto Lyra Villas Bôas ◽  
Talita Aparecida Pletsch
Keyword(s):  
Test Bench ◽  
Operating Time ◽  
Chemical Precipitation ◽  
State University ◽  
Uniformity Coefficient ◽  
Agricultural Engineering ◽  
Paulo State ◽  
Significant Difference ◽  
Distribution Uniformity ◽  
Operational Time

1 RESUMO Este trabalho teve por objetivo estudar a variação de vazão em tubogotejadores NaanPC laranja e NaanPC azul em função  de precipitados químicos, ao longo do tempo de funcionamento, quando submetidos a uma água rica em ferro, avaliando-se especificamente o coeficiente de uniformidade de Christiansen (CUC) e o coeficiente de uniformidade de distribuição (CUD). O experimento foi desenvolvido em uma bancada de ensaios para tubogotejadores no Laboratório de Ensaio de Equipamentos para Irrigação do Departamento de Engenharia Rural da Faculdade de Ciências Agronômicas - UNESP, localizado no município de Botucatu – SP. O experimento foi montado em esquema fatorial 2x2x7, sendo duas doses de Fe, dois modelos de gotejadores e sete tempos de funcionamento, com três repetições, totalizando 84 parcelas experimentais. Efetuou-se a análise de variância pelo teste F. As médias das vazões dos gotejadores foram comparadas pelo teste de T de Student a 5% de probabilidade. Os resultados obtidos não apontaram diferença significativa nas diferentes doses de ferro. Entretanto, os resultados apontaram diferença significativa na interação gotejador x tempo e coeficiente de uniformidade de Christiansen (CUC). UNITERMOS: coeficiente de uniformidade de Christiansen(CUC), coeficiente de uniformidade de distribuição (CUD), entupimento de emissores.  BRAUER, R.L; CRUZ, R. L; VILLAS BÔAS, R. L.; PLETSCH, T. A.EVALUATION OFWATER APPLICATION UNIFORMITY IN DRIPPERSIN FUNCTION OF IRON CONTENT 2 ABSTRACT This work aimed to study the occurrence of chemical precipitates effects in two types of drip hose (NaanPC orange and blue) due to chemical precipitation along the  operating time, when subjected to water rich in iron, specifically evaluating the Christiansen uniformity coefficient (CUC) and distribution uniformity (DU). The experiment was conducted in a test bench for  drip hose at Laboratory Test Equipment for Irrigation - Department of Agricultural Engineering, Sao Paulo State University. The experiment was a 2 x 2 x 7 factorial design, with two Fe doses, two drip brands, and seven operational times with three replicates, totalizing 84 experimental plots. The variance analysis was performed by F test. Average emitter discharges were compared by Student t test at 5% probability. The results showed no significant difference in iron doses. However, the results indicated significant differences in drip versus operational time and the Christiansen uniformity coefficient (CUC).  KEYWORDS: Uniformity coefficient of Christiansen(CUC), distribution uniformity (DU), emitter clogging.

scholarly journals Spatial variability of available water and micro-sprinkler irrigation in cambisol

Revista CERES ◽  
2016 ◽  
Vol 63 (6) ◽  
pp. 782-788
Author(s):  
Larissa Luana Nicodemos Ferreira ◽  
Luis César de Aquino Lemos Filho ◽  
Marcílio Macêdo Torres ◽  
Raimundo Fernandes de Oliveira Júnior ◽  
Clara Nívea Costa do Vale ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Flow Rate ◽  
Sprinkler Irrigation ◽  
Sprinkler System ◽  
Water Application ◽  
Uniformity Coefficient ◽  
Water Capacity ◽  
Available Water ◽  
Available Water Capacity ◽  
Distribution Uniformity

ABSTRACT The technology of irrigation is vital for agricultural production. Thus, description of spatial patterns of both water application and available water capacity in the soil, as well as their interactions, is essential to maximize efficiency of water use in irrigated areas. The objective of this study was to analyze spatial variability of available water capacity in the soil and water application via irrigation using geostatistics. The experiment was conducted in a commercial mango orchard in Cambisol irrigated by micro sprinkler system, in the municipality of Alto do Rodrigues, RN. Analyses of descriptive statistics and geostatistics were performed using the programs GeoR and GS+. Geostatistics was found suitable for describing the structure of spatial dependence of available water capacity in the soil and the flow rate distributed in the area by sprinklers. Moreover, even with good results for Christiansen Uniformity Coefficient (CU) and Distribution Uniformity Coefficient (DU), the area showed spatial variability of flow rate.

Study of the Dynamics of the Adsorption of Trichloroethylene (TCE) on Active Carbons

2019 ◽  
Vol 23 (9) ◽  
pp. 30-35
Author(s):  
A.K. Gorelkina ◽  
T.A. Krasnova ◽  
I.V. Tymoshchuk ◽  
N.V. Gora ◽  
N.S. Golubeva
Keyword(s):  
Mass Transfer ◽  
Functional Groups ◽  
Flow Rate ◽  
Operating Time ◽  
Carbon Surface ◽  
Dynamic Adsorption ◽  
Constant Flow ◽  
Active Carbons ◽  
Coal Surface ◽  
Constant Flow Rate

The dynamics of adsorption of trichloroethylene from aqueous solutions on active carbons (AC) of the SKD-515, ABG, Purolat-Standart grades, differing in composition, method of preparation, structure and chemical state of the surface, was studied. The operating time of the filtering layer before breakthrough decreases in the series SKD-515> ABG> Purolat-Standart coal, which is caused by the porous structure of the coal and the nature of the oxygen-containing functional groups on the carbon surface. It was also noted that adsorption is influenced by the interaction of TCE with functional groups of the coal surface. The efficiency of TCE adsorption on various active carbons at a constant flow rate was studied. It was shown that a decrease in the flow rate of the solution through the filter increases the dynamic adsorption capacity, which indisputably confirms the pore-diffusion inhibition of mass transfer.

scholarly journals ENTUPIMENTO DE GOTEJADORES CONVENCIONAIS POR PRECIPITADOS QUÍMICOS DE CARBONATO DE CÁLCIO E MAGNÉSIO, COM QUATRO ÍNDICES DE SATURAÇÃO DE LANGELIER

Irriga ◽  
2008 ◽  
Vol 13 (4) ◽  
pp. 525-539 ◽  
Author(s):  
Ralini Ferreira de Mélo ◽  
Rubens Duarte Coelho ◽  
Marconi Batista Teixeira
Keyword(s):  
Water Distribution ◽  
Saturation Index ◽  
Operating Time ◽  
Test Conditions ◽  
Terra Preta ◽  
Langelier Saturation Index ◽  
Distribution Uniformity ◽  
Calcium And Magnesium ◽  
Saturation Indexes ◽  
Bench Testing

ENTUPIMENTO DE GOTEJADORES CONVENCIONAIS POR PRECIPITADOS QUÍMICOS DE CARBONATO DE CÁLCIO E MAGNÉSIO, COM QUATRO ÍNDICES DE SATURAÇÃO DE LANGELIER  Ralini Ferreira de Mélo1; Rubens Duarte Coelho2; Marconi Batista Teixeira21Escola Agrotécnica Federal de Vitória de Santo Antão, Propriedade Terra Preta, Vitória de Santo Antão, PE, [email protected] de Engenharia Rural, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, SP  1 RESUMO Com o objetivo de avaliar a influência da indução forçada de precipitados químicos à base de carbonatos de cálcio e magnésio no coeficiente de variação e uniformidade de distribuição de água, foi realizado um ensaio no Laboratório de Irrigação da ESALQ/USP, utilizando-se quatro índices de saturação de Langelier (ISL): ISL -2,268; ISL 0,469; ISL 1,156 e ISL 1,439. Em cada ensaio com um determinado ISL, foram utilizados oito tipos de gotejadores convencionais, instalados em uma bancada com11 mde comprimento. As obstruções observadas nos gotejadores, tanto parciais como totais decorrentes do tempo de funcionamento, resultaram em aumento do coeficiente de variação e redução drástica da uniformidade de distribuição de água. Para as condições de ensaio realizado, observou-se que o índice de saturação de Langelier não deve ser usado como único parâmetro para prever a obstrução dos gotejadores. UNITERMOS: irrigação localizada, cálcio e magnésio, Índice de Saturação de Langelier.  MÉLO, R. F.  de; COELHO, R. D.; TEIXEIRA, M. B. CLOGGING OF A COMMERCIAL DRIPPERS BY CALCIUM AND MAGNESIUM PRECIPITATES USING FOUR LANGELIER SATURARION INDEXES  2 ABSTRACT An essay was carried out in the laboratory of irrigation at ESALQ/USP   to evaluate the effect of calcium and magnesium precipitates on the variation and uniformity coefficients in irrigation drippers. Four Langelier saturation indexes (LSI) (-2,268; 0,469; 1,156; 1,439) and eight commercial drippers were used. They were installed on an 11m bench testing apparatus. Both partial and total obstructions of the drippers were observed over the operating time increasing the variation coefficient and reducing the water distribution uniformity. Within the test conditions, LSI should not be used as a single parameter to estimate dripper clogging. KEY WORDS: drip irrigation, calcium and magnesium, Langelier saturation index

scholarly journals Impact du prétraitement au sel (NaCl) et du séchage sur les caractéristiques nutritionnelles et microbiologiques de l’oignon bulbe

2020 ◽  
Vol 14 (3) ◽  
pp. 685-697
Author(s):  
Clarisse Sidbewendé Compaore ◽  
Hamidou Compaore ◽  
G.O. Inoussa ◽  
Hagrétou Sawadogo-Lingan
Keyword(s):  
Burkina Faso ◽  
Microbiological Quality ◽  
Drying Process ◽  
Total Sugars ◽  
Microbiological Characteristics ◽  
Drying Technology ◽  
Iron Manganese ◽  
The Impact ◽  
Manganese Magnesium

La culture de l’oignon contribue fortement à la sécurité alimentaire et à la lutte contre la pauvreté au Burkina Faso. Cependant, plusieurs contraintes dont les pertes post-récoltes entravent le développement de cette filière. L’objectif de cette étude était d’évaluer l’impact d’un procédé de séchage sur la qualité de l’oignon. L’oignon après parage, a été prétraité (NaCl à 5%) ou non, puis séché avec un séchoir à gaz Atesta (60-65 °C, 10-12 h). Les caractéristiques nutritionnelles et microbiologiques des produits frais et séchés ont été déterminées par des méthodes standardisées. Sur la base de la matière sèche, les résultats ont donné pour l’oignon frais, 5,19%, 1,7%, 12,16% et 47,56%, respectivement pour les cendres, matières grasses, protéines et sucres totaux. Après séchage, les teneurs ont varié respectivement de 2,96 à 31,31%, de 0,59 à 0,77%, de 3,58 à 7,78% et de 36,88 à 49,56% pour les cendres, matières grasses, protéines et sucres totaux. Malgré l’effet du prétraitement et du séchage, les teneurs en fer, manganèse, magnésium, zinc et calcium sont restées intéressantes. Les oignons séchés, en l’occurrence ceux prétraités avec le sel étaient de bonne qualité microbiologique. La vulgarisation de cette technologie permettra une meilleure valorisation de l’oignon au Burkina Faso.Mots clés : Séchoir à gaz, procédé, qualité, Burkina Faso.   English Title: Impact of pretreatment with salt (NaCl) and drying on the nutritional and microbiological characteristics of onion bulb The production of onion greatly contributes to food security and the fight against poverty in Burkina Faso. However, several constraints including post-harvest losses hinder the development of this sector. The objective of this study was to assess the impact of drying process on the quality of onion. Onion after trimming, was pretreated (NaCl at 5%) or not and dried with a gas dryer Atesta (60-65 °C, 10-12h). Nutritional and microbiological characteristics of fresh and dried products were determined using standard methods. Based on the dry mater, results showed that fresh onion contains 5.19% of ash, 1.7% of fat, 12.16% of proteins and 47.56% of total sugars. After drying, ash, fat, proteins and total sugars content varied from 2.96 to 31.31%, 0.59 to 0.77%, 3.58 to 7.78% and 36.88 to 49.56%, respectively. Despite the effect of pretreatment and drying process, the content of iron, manganese, magnesium, calcium and zinc remained interesting. The dried onions, in particular those pretreated with salt presented good microbiological quality. The dissemination of onion drying technology will allow to add value to onion in Burkina Faso.Keywords: Gas-drier, process, quality, Burkina Faso.  

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.

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