Design and Planning for Efficient Irrigation
To install an irrigation system properly and with guarantees, careful design and planning are required to select, size, and position all the components that will enable irrigation to be carried out with the levels of uniformity in water application and degree of autonomy required.
The Characteristics of the Irrigation Area (size, geometry, and topography), the the benefits of design and the level of investment These desired conditions determine the spatial distribution of supply pressure values in the Irrigation area, which, together with the type of emitter selected, determine the uniform water distribution in the field (spatial distribution of flow rates within the irrigation area).
From an agronomic perspective, it is assumed that all plant material within a given irrigation sector has the same genetic potential and is subject to the same soil and climatic conditions; therefore, to obtain a uniform crop response, it is necessary to take into account hydraulic design criteria that allow for the delivery of the same volumes of water and nutrients to all plants within each irrigation sector.
The Role of the Irrigation Head / Head Unit and Filtration
The irrigation head plays a a key role in meeting the necessary water supply needs for each irrigation sector. To do this, it is necessary to have a water source that provides the required flow rates and pressures, taking into account the filtration equipment and other components of the irrigation head / head unit. Filtration plays a crucial role in trapping particles in the water, preventing clogs in the dripline systems and ensuring an adequate supply.
One of the Main Functions of the Irrigation Head / Head Unit It involves meeting the hydraulic requirements (flow rate and pressure) demanded by each of the irrigation sectors. To do so, the supply source (pumping equipment, pressurized distribution network, or gravity-fed pipeline) must meet the hydraulic requirements of the field installation plus the anticipated consumption (flow rate and pressure in the form of a differential) by the filtration equipment and other components that make up the irrigation head / head unit.
The only increase in pressure differential that occurs in an irrigation head / head unit and that does not depend directly on changes in the system’s hydraulic demand required by the field installation is that caused by clogging of the filtering element. This is due to the retention of a large portion of the particles carried in suspension by the water, thereby preventing them from entering the water transport and distribution pipes leading to the points of consumption—the emitters.
During irrigation, the operating pressure in the field network is the difference between the pressure supplied by the pumping equipment and the pressure losses occurring at the irrigation head / head unit; since this second parameter is variable, situations may arise during Irrigation in which operating values fall outside the range established during the design phase.
Operating conditions outside the projected values result in a loss of uniformity and, consequently, uneven crop development, which ultimately leads to a decrease in production and an increase in the payback period for the capital invested in the Irrigation system.
Maintenance for Optimal Operation
An irrigation system must operate in accordance with the design parameters, not only during the initial setup and commissioning of the system, but also throughout its entire service life; to this end, it is necessary to perform the maintenance work that ensure proper operation. Maintenance of an irrigation system is necessary to maximize the service life of its components and to ensure that the uniformity of water distribution and the system’s efficiency do not decline over time.
Proper maintenance involves performing the necessary tasks with the intensity and frequency required to ensure that all system components are in good working order before and during the irrigation season.
Advantages of Automatic Filtration Systems
The automatic filtration systems They exhibit predictable behavior with respect to the generated pressure differential range. The lower end of the range is determined by the head loss generated in the filtration unit due to the flow rate required by the field installation when the filtering elements are completely clean (this data is provided by the manufacturers), and the upper end of the range corresponds to the pressure differential value selected to trigger the unit’s self-cleaning activation (a value of 0.5 bar or close to it is typically used). Any foreseeable situation can be taken into account during the design phase, thereby ensuring that the supply pressure to the field installation will never be compromised by the stand-alone Filtration equipment.
Limitations of Manual Filtration Systems
The manual filtration systems They lack the full autonomy characteristic of automatic filtration systems. The minimum and maximum values of the pressure differentials generated during the filtration process depend on factors that are difficult to control during the design phase.
- The pressure differential value at the lower end It is determined by the sum of the head loss generated in the filtration equipment by the circulating flow rate when the filtering elements are completely clean, plus the head loss caused by the lack of effectiveness of manual cleaning, which is influenced by the qualifications, time availability, and resources of the operating personnel.
- The pressure differential value at the upper end For each type of filtration media, it is determined by: the operating time elapsed since the last cleaning, the effectiveness of the cleaning process, the quality of the available water, and the operating flow rate assigned per filter or per unit filtration area (liters per hour per cm2).
Changes in the pressure differential must be monitored, analyzed, and corrected by operating personnel to prevent the pressure differential from exceeding the maximum value specified during the design phase. This means that if these inspection and maintenance tasks are not performed with the required frequency, pressure differentials higher than expected may occur, thereby leading to situations that result in working conditions and outcomes different from those anticipated.
Key Differences Between Automatic and Manual Filtration
| Situation | Automatic | Manuals |
| Cleaning the Filtering ElementAutonomy | Autonomous: The self-cleaning sequence is activated when the programmed time interval or pressure differential value is reached. It does not depend on the availability of operating personnel. | Manual, with no precise control over the time intervals (variable frequency) or the pressure differential values at which each cleaning is performed (pressure differential values vary with each cleaning). When? Depends on the availability of operating personnel. |
| Cleaning the Filtering ElementEffectiveness | Requirements specified in the design phase. Assurance of the hydraulic requirements (flow rate and pressure) necessary to effectively clean the filtration media. | The effectiveness of filtration media cleaning depends on the qualifications, time availability, and resources of the operating staff. |
| Cleaning the Filtering ElementFrequency | The frequency of cleaning depends on the quality of the available water and the sizing criteria used during the design phase. | The frequency of cleanings depends on the quality of the available water, the sizing criteria used during the design phase, and the effectiveness achieved during each cleaning performed by the operations staff. More frequent cleanings. |
| Differential pressureInterval width | Values within the range specified during the design phase. The minimum value of the range is determined by the differential pressure for the flow rate when the filters are completely clean, and the maximum threshold by the value set for triggering the self-cleaning sequence (usually 0.5 bar). | Increasing up to what value? The minimum value of the range depends, among other factors, on how effectively the filtering element is cleaned manually, and the maximum value that can be reached is determined by the characteristics of the pumping equipment and the Frequency of inspection. |
| Hydraulic interactionUpstream filtration system | Minimal or no hydraulic interaction between the source supplying the hydraulic requirements and the filtration equipment due to the narrow range of the maximum differential pressure that can be reached; always less than 0.5 bar. | The intensity of the hydraulic interaction is determined by variations in the flow rate and pressure of the pumping system in response to an increase in the differential pressure generated in the Filtration system. There is a possibility of reaching critical pressure levels that could compromise the strength and service life of certain components. |
| Hydraulic interactionDownstream filtration system | The hydraulic requirements of the field installation are met without compromising the filtration equipment. The maximum pressure differential generated is determined during the design phase and corresponds to the value set for triggering the self-cleaning sequence. | Supply of the hydraulic requirements needed by the field installation, as determined by the pressure differential values present at any given time. High pressure differential values significantly reduce the supply pressure to the field installation. |
| Hydraulic Interaction Uniformity water application schedule | The temporal uniformity of irrigation water application is not affected by the narrow range of the maximum differential pressure that can be reached, which is always less than 0.5 bar. | The consistency of irrigation water application over time is compromised and depends on the timely cleaning of the filtration media. |
| FiltrationEnergy consumption | -Low consumption due to low average and absolute pressure differentials. | -Higher energy consumption associated with high average and absolute pressure differentials. |
| Filtering elementService life | Not dependent. There is no risk of the filtration media breaking due to the pressure differential values generated and the exposure conditions during the autonomous cleaning process. | Caution. High pressure differentials can damage certain types of filtration media. Manual cleaning of the filtration media by operating personnel can damage the media if not performed properly. |
In conclusion, the installation of filtration systems for agricultural irrigation is essential to ensure an optimal and consistent water supply. Automatic systems offer significant advantages in terms of predictability and guaranteed supply pressure, while manual systems have limitations that can compromise irrigation efficiency.
At AZUD, we offer a wide range of automatic and manual filtration systems, including:
- Filtration systems featuring disc technology and automatic cleaning, such as AZUD HELIX AUTOMATIC
- Filtration systems using disc technology and manual cleaning, such as AZUD HELIX SYSTEM
