Introduction: Micro-irrigation filters serve as crucial equipment at the forefront of drip irrigation systems. Poor filter quality or inefficient design can lead to increased operational costs, decreased water quality, or even system failure. Thus, the advancement of micro-irrigation technology demands cutting-edge filters. Currently, most filters used are manually backwashed and horizontally structured, occupying significant space and incurring high production costs. Users require technologically advanced automatic filters.
I. Structure and Working Process
1. Structure
The LZ vertical fully automatic filter consists of:
- Filter tank
- Screen pipe (filter element)
- Automatic control components
- Electric drain valve
- Manual drain valve
- Power transmission components
2. Working Process
Under the action of the water pump, irrigation water enters the tank through the inlet, passing through the screen pipe’s gaps from the inside to the outside. Solid particles in the irrigation water larger than the screen pipe clearance are trapped on the inner wall of the screen pipe. When sediment accumulates to a certain level, the pressure difference between the inlet and outlet increases. Upon reaching the preset pressure difference, the pressure difference controller sends a switch signal, opening the electric drain valve. The suction device is rotated by the transmission mechanism, and the inward water flow washes the inner cavity of the screen pipe sequentially through the suction disc, discharging dirty water from the drain outlet. As the dirt is removed, the pressure difference between pre-filter and post-filter gradually decreases. When it drops to the lower limit of the set pressure difference, the pressure difference controller sends another signal, closing the electric drain valve and the main rotating motor, ending the drainage process. The filter achieves backwashing of each screen pipe sequentially through motor-driven self-cleaning pipes while other screen pipes continue normal filtration.
The manual drain valve is mainly used to discharge impurities when water quality is poor. The opening frequency and interval time are determined based on water quality conditions.
II. Main Technical Parameters
- Design Pressure (MPa): 0.6
- Filtration Accuracy (Mesh): ≤120
- Cycloidal Pinwheel Reducer Transmission Ratio: 1:8491
- Design Pressure Difference (MPa): 0.02～0.16
III. Key Components
1. Filter Element
The filter element is an 80mm diameter stainless steel filter core, made of stainless steel trapezoidal winding wire with support rings at both ends and rectangular ribs in the middle as the wire frame. All parts are made of stainless steel and welded into an integral structure. Different clearance of winding wires constitutes different filtration mesh numbers.
2. Drainage Mechanism
The drainage mechanism consists of a suction disc, spring, suction pipe fork, support base, drain pipe, and electric drain butterfly valve made of copper alloy. The drainage mechanism and the screen pipe are separately installed in two chambers, separated by baffles. The suction disc is tightly attached to the smooth baffle and rotates along the smooth lower baffle under the drive of the transmission mechanism to extract dirt from the inner cavity of the screen pipe. The suction disc is made of wear-resistant copper alloy to enhance the wear resistance of the mechanism.
3. Transmission Mechanism
The transmission mechanism consists of an electric motor, coupling, transmission components, adapter plate, and square sleeve. The motor is fixed on the top of the tank by a bracket, and the transmission shaft is inserted into the square sleeve through the coupling. The shaft and the square sleeve are fixed with top wire, and the square sleeve and the transmission shaft adapter plate are integrated. They are connected to the suction pipe fork through bolts. Thus, the power of the motor drives the suction pipe fork to rotate.
4. Automatic Control Device
The automatic control device consists of a pressure difference controller, time relay, electromagnetic drain valve, etc. Automatic backwashing can be achieved by setting the time and pressure difference. The backwashing interval time can also be set using a time relay, with a range of 0 to 10 hours, and the backwashing time is set using a time relay with a range of 0 to 180 seconds. The two ends of the pressure difference controller are connected to the inlet and outlet, respectively. The controller is connected to the electromagnetic drain valve and the transmission motor via wires. Users set a pressure difference value based on the allowable pressure drop of the pipeline and switch difference according to the backwashing time requirements. When the pressure difference or time between the inlet and outlet reaches the set value, the pressure difference controller sends a signal to start the electromagnetic valve and the transmission motor.
IV. Features
Compared to conventional filters, this filter has the following advantages:
- The filter core is made of a novel trapezoidal stainless steel wire winding, which makes it difficult for solid particles to be trapped during filtration and easy for them to detach during backwashing. It has a large effective filtration area, high filtration accuracy, and long service life.
- Small size, light weight, large flow rate, easy installation, and simple maintenance.
- Backwashing can be performed without stopping the machine, ensuring the normal operation of the screen pipe. During backwashing, the screen pipes inside the tank are cleaned one by one, while other screen pipes continue to work.
- The backwashing suction disc is made of copper alloy and is separately installed in two chambers with the screen pipe, reducing the wear of the suction disc, making the mechanism reliable and durable.
- In addition to automatic backwashing function, manual backwashing function is also provided.
- High interception efficiency, low water consumption during backwashing, and low pressure drop.
- The entire machine is internally and externally sprayed with plastic, with good corrosion and rust resistance.
