There are many solutions for level monitoring in industrial environments. This has driven the rapid development of level controllers. Controlling the level of liquid in tanks, containers and environmental waterways is essential for many different processes. Sino-Inst offers a range of level control devices. Designed to meet the needs of various level control applications. This article will specifically introduce the tank level control process.
What is a Tank Level Controller?
Level controllers maintain the optimal level in different industrial applications. It is an important instrument to ensure efficiency and safety. Such controllers can accurately monitor and regulate the level of containers. such as tanks and water tanks. It prevents overflow and idling. Maintains process stability. The Level Controller is called a level switch.
Level Controller/Switch Types:
【Float level switch】
The design of the float level switch is based on the principles of buoyancy and static magnetic field. In the float level switch, a float with a magnet will float up and down in the measured medium due to buoyancy. The change in liquid level will cause the corresponding change in the position of the magnetic float. The change will then interact with the sensor to generate a switch signal.
【Tuning fork level switch】
In the tuning fork level switch, the frequency change of a pair of piezoelectric crystals is the key. The tuning fork can vibrate continuously at a specific resonant frequency.
When in contact with the measured medium. The changes in its frequency and amplitude are captured by the intelligent circuit and converted into a switch signal.
【 Capacitive level switch 】
The working principle of the capacitive level switch is based on the effect of material level changes on capacitance. When the liquid level changes and the area covering the probe changes, the capacitance value will also change. This change is captured by the intelligent circuit to achieve accurate measurement of the liquid level.
【 External level switch 】
The external level switch uses “frequency conversion ultrasonic technology” to detect the liquid level. It is without contacting the liquid. By detecting the amplitude change of the residual vibration signal. It can be determined whether the liquid has overflowed the probe.
【 Radio frequency admittance level switch 】
Radio frequency admittance technology measures admittance through high-frequency signals. This technology has a variety of measurement parameters and higher accuracy and reliability. It can be used on a variety of occasions.
When the material acts on the rotating blades, and produces a rotation-blocking effect. The overload detector monitors the obstruction of the rotating blades. It sends a corresponding signal to trigger the control circuit.
【 Electromagnetic level switch 】
The electromagnetic proximity switch converts the signal by attenuating the electromagnetic wave. When the front end of the switch encounters a metal object, the metal absorbs part of the electromagnetic wave. Causes electromagnetic attenuation, which is converted into a switch signal.
[Photoelectric Liquid Level Switch]
Photoelectric liquid level switches rely on changes in light refraction and reflection.
At the junction of different media. The changes in light reflection and refraction intensity will be detected by the photoelectric switch.
[Ultrasonic Liquid Level Switch]
Ultrasonic liquid level switches measure liquid level by ultrasonic reflection time. This switch can be used for a variety of liquid media and is not affected by liquid color or bubbles.
What is a Tank Level Control System?
Liquid level control systems are used to control the liquid level height in storage tanks. Liquid level control systems maintain the proper liquid level in large industrial storage tanks.
Working Principle of Liquid Level Control System
The working principle of the liquid level control system is based on the synergy of sensors and controllers. Sensors are usually installed at different locations of liquid containers. Used to measure the height or pressure of the liquid level. These sensors convert liquid level information into electrical signals. Transmit them to the controller. The controller adjusts the liquid level through valves or pumps based on the received signals.
Design of Liquid Level Control System. The design of the liquid level control system needs to consider multiple factors.
Properties of the liquid. The shape and size of the container. Environmental conditions, etc. During the design process, engineers need to select appropriate sensors and controllers. Perform appropriate calibration and debugging. In addition, the reliability and safety of the system are also important considerations in the design.
Tank Level Control Methods
Contact measurement:
Control the liquid level height by direct contact with the medium. The float level switch can set 4 consecutive points to control the liquid level height. When the set point is exceeded, the float level switch will sound an alarm.
Non-contact measurement:
Ultrasonic level switches and radar level switches do not directly contact the medium. They are attached to the outside of the tank, and when the liquid exceeds the position where the level switch is placed. The level switch will send a signal to alert the staff.
Continuous measurement:
The radar level switch can continuously measure the height of the liquid level. When paired with a display instrument, the staff can observe the changes in the liquid level in real time. We can also set the liquid level height. When the liquid level is higher or lower than the liquid level, the radar level switch will sound an alarm.
How to Control Water Level in a Tank?
Solutions to the problem of the liquid level:
1. Install a liquid level controller:
The feed or discharge flow can be adjusted in real time according to the change of the liquid level, so as to maintain the stability of the liquid level and reduce fluctuations.
2. Install a float fluctuation valve:
The flow of the inlet and outlet liquid is controlled by the up and down movement of the float, thereby controlling the fluctuation of the liquid level.
3. Improve the stirring effect:
By increasing the speed of the agitator or improving the vortex of the agitator, the mixing effect of the liquid is enhanced, thereby reducing the fluctuation of the liquid level.
4. Control the opening of the inlet and outlet valves:
Control the opening of the inlet and outlet valves according to the height of the liquid level, thereby reducing the fluctuation of the liquid level.
How to Control Corrosive Media Level in a Tank?
There are two ways to measure corrosive media. Contact measurement and non-contact measurement.
Contact measurement method:
The material of the liquid level controller is compatible with the measured liquid. Commonly used materials for measuring corrosive media are: 316 Stainless steel. PVC. Coated Level Electrodes. Hastelloy. Carbon Graphite, PTFE, and other materials are available upon request.
Non-contact measurement method:
Use radar and ultrasonic level controllers. The level controller can be directly attached to the outside of the tank. At this time, the measured medium is not in contact with the measuring instrument. The corrosiveness of the medium will not affect the measurement results.
Tank Level Control Applications
1. Food Industry
Tank level control is widely used in the food industry. For example,
Beverages in the food industry: milk, soy milk, beverages, juice, etc.
Snacks: jelly, tortoise jelly, potato chips, etc.
Condiments such as: ketchup, sesame paste, peanut butter, bean paste, salad dressing, soybean paste, hot pot base sauce, barbecue sauce, etc.
2. Daily Chemical Industry
Tank level control is also used in the daily chemical industry. For example, common daily chemical products. such as laundry detergent, hand soap, shower gel, shampoo, etc. Tank level control can be used for liquid level control.
3. Chemical Industry
Tank level control also plays its role in the chemical industry. Such as paint, glue, lubricant, various liquid chemicals, etc. Tank level control can be used for liquid level control.
4. Shipbuilding Industry
In the ballast water tank, fuel tank and other compartments of the ship, the liquid level switch is used to monitor the liquid level. Through the signal feedback of the liquid level switch. The crew can understand the liquid level of each compartment.
5. Agricultural Irrigation
In the water storage tanks, canals and other facilities of the agricultural irrigation system, the liquid level switch can help farmers better manage water resources. When the water level in the water storage tank is lower than a certain value. The liquid level switch can control the water pump to pump water from the water source to replenish the water in the tank.
6. Medical Industry
Tank level control is used to calculate reagents, intravenous infusion and other medical products.
How to Lower the Tank Water Level?
When the internal pressure of a closed buffer tank drops or is completely pressure-free, the water level can be lowered by draining it with an external pump.
The specific operation is as follows:
(1) First, connect the external pump to the water level in the tank through a pipeline. If the liquid level is high, select a suitable location for connection according to the actual situation.
(2) Turn on the external pump switch, introduce high-pressure liquid, and drain the water in the tank to below the required level. At the same time, pay attention to the negative pressure to avoid excessive negative pressure in the tank;
(3) After draining, turn off the external pump switch and cut off the laid pipeline connection.
In addition to draining with an external pump, there are other ways to lower the water level. For example, the liquid can be drained through channels such as the tank drain hole. Adsorption can be performed using chemical adsorbents and other materials. Specific measures should be taken according to the actual situation.
How do I Know the Level of Water in My Tank?
When using a tank, you need to monitor the liquid level in the tank at any time. The following is a method for measuring the liquid level.
Weighing method:
Weigh the tank first, then weigh the weight of the tank when it is filled with liquid. Subtract the weight of the empty tank from the weight of the tank to get the weight of the liquid in the tank. Calculate it to get the liquid level.
However, this method requires weighing and calculation on time. The process is more troublesome. And the accuracy of the data may not be guaranteed. Wooden stick, liquid level ruler method
Using a long wooden stick or a liquid level ruler
Find a liquid level ruler or a solid wooden stick, insert it into the bottom center of the liquid tank container, wait for 10 to 15 seconds, and then take it out. The wet part is the height of the liquid.
This method is economical, safe, and labor-saving, but it cannot guarantee data accuracy.
Digital liquid level gauge
A digital liquid level gauge is an instrument that can measure the liquid level in a container. The digital display screen can accurately read relevant data. Before replacing the digital level gauge, first make sure the tank is empty and pressure-free. Then take out the digital level gauge, put on the sealing ring, install it on the mouth of the liquid tank, and tighten it with a wrench.
Level Meters VS Level Controller
A level switch is a simple device used to detect whether a liquid has reached a specific height. When the liquid reaches a preset threshold, the level switch triggers a mechanical action or sends an electrical signal.
A level gauge is a more complex device used to measure and display the exact height or depth of a liquid. It can be analog or digital and provide continuous level readings.
Tank level control is a complex process. There are many ways to control the level: level controllers, level switches, and level control systems can all measure the level. Different working conditions require different levels of control instruments. However, tank level control can be customized. There is always a customized solution that suits you.
Sino-Inst has been engaged in level control for more than 20 years. We can provide you with a level control solution that suits you. If you need anything, please feel free to contact us.
