Industrial float level sensors

Types of industrial float level sensors

Industrial float level sensors, essentially liquid measurement devices, are in different manufacturing setups. They apply to liquid and some slurry conditions. These sensors come in the form of simple mechanical devices, electronic devices that give accurate readings, and high-tech ultrasonic sensors. In most studies and analysis, these sensors are classified as follows:

Mechanical Float Sensors

This simple design comprises a metal ball and magnetically controlled reed switch inside the float. When the float rises or lowers, the ball or magnet inside the float may cause the switches to open or close. In this way, this float is used to measure the level of liquid in storage tanks, sumps, and other containers.

Magnetostrictive Sensors

These sensors comprise a rigid, thin metallic wire, a void or a float shell, and a magnet inside the float. When the float changes position, the magnet inside the float will also change the position in relation to the wire. When the magnet comes close to the wire, it creates magnetic pulses (out of magnetostrictive effect) that travel in the wire. The sensor detects the time it takes for the pulse to travel to the float, allowing it to measure the liquid level within the tank. These industrial float level sensors find their best applications in oil and chemical storage tanks, fuel tanks, and any other tank requiring precision measurements and resistance to environmental conditions.

Hydrostatic Pressure Sensors

This type of industrial level float sensor is designed to measure the level of liquids or fluids based on the pressure exerted by the fluid at a given depth. It is very useful where floats cannot work due to turbulence or surface foam. These sensors are applied where measurements are taken at a certain depth or submersion, such as water supply reservoirs, wastewater treatment tanks, and nuclear cooling ponds.

Capacitive Level Sensors

Capacitive level sensors consist of two conductive plates mounted concentrically. The plates are separated by a dielectric material, such as an insulator. In operation, when the float rises, the space between the plates decreases, increasing the sensor capacitance. Conversely, lowering the float increases the distance between the plates and decreases the sensor capacitance. These sensors are ideal for measuring the levels of the powdery and liquid materials used in the plastic, food processing, and pharmaceutical industries.

Industrial float level sensor function, features and design

Function

The core working principle behind the sensor relies on the variable levels the liquid exhibits within a closed tank. As the liquid rises or falls, its movement is transmitted or communicated to an output section of the sensor, which gives the measurements and readings.

Features

Industrial float level sensors have the following core features:

• Continuous Measurement: Unlike some point level sensors that measure only at specific points, float level sensors provide a continuous measurement of liquid level. This feature is very important in processes where maintaining a certain level of liquid is critical to avoid overflow or dry conditions.
• High Accuracy and Reliability: Seal level float sensors accurately measure liquid levels in various liquids and some slurries. This makes them valuable in industries where precision is critical, such as chemical processing or food and beverage manufacturing.
• Diverse Material Tolerance: Float level sensors are made from various materials, such as stainless steel, plastic, and glass, depending on the industry requirements, such as temperature and pressure conditions. Hence, this makes them very versatile and applicable in various industrial environments.
• Simple and Robust Design: The design simplicity means the sensors are easy to install, operate, and maintain. They are very durable and handle extreme conditions like high pressure, temperature, and corrosive liquids.
• Integration Capabilities: These float sensors are designed to be easily integrated into existing control systems, including PLCs (programmable logic controllers) and SCADA (supervisory control and data acquisition) systems. This allows real-time monitoring and data collection for process optimization.

How the Design Influences the Product's Feature

The design of the industrial float level sensors significantly impacts their performance, features, and applications. The float's shape, size, and material are determined based on the specific requirements of the industry where it will be used.

The guide pipe, for example, is designed with an aperture that allows the float to move freely as the liquid level changes. This movement is what causes a change in the float's magnetic field, which is internally translated into an electronic signal to show the liquid level in the tank. This helps to maintain precision in measurement and ensures that the sensor is as stable and accurate as possible, regardless of the conditions in which it operates.

Scenarios for industrial float level sensors

Industrial float level sensors measure the liquid level in tanks in almost all industrial applications. They apply to everything from oil and gas to water treatment and food processing. Below are some specific scenarios where these sensors come in handy:

Oil and Gas Industry

In the oil and gas exploration and production process, industrial level float sensors are crucial in measuring the level of crude oil, gas, and water in storage tanks and separators. Because of the high pressure and temperature conditions in the processing and refining stage, the sensors are made of strong stainless steel or other durable materials to withstand these adverse conditions and measure the levels accurately. They are auto alarm systems, so when the tank level reaches a certain level, the users and control systems are notified and then prevent overfilling or running empty to maintain safety and efficiency.

Water and Wastewater Treatment

Industrial float level sensors monitor water and wastewater in treatment plants. They measure the levels in the treatment basins, clarifiers, and holding tanks. They provide data for controlling pumps, valves, and other equipment in real time. The sensors are also used to maintain optimal levels of water and sludge in these treatment facilities. They help automate the feeding and discharge processes in these treatment basins, facilitating the maintenance of desired levels for effective treatment outcomes. The sensor material used must be corrosion-resistant because the water and waste contents can be very acidic or alkaline.

Food and Beverage Industry

Food and beverage manufacturers also use industrial float level sensors to measure the level of liquids such as water, milk, juices, and beer in storage tanks and processing vessels. Because of the nature of this industry, the sensors must be made of materials that are easy to clean and safe for contact with foods and beverages. These sensors also help maintain accuracy in inventory management and prevent overflows in storage tanks, increasing efficiency.

Chemical Processingp>In the chemical processing industry, these level float sensors measure the levels of various chemicals and mixtures in storage tanks, reactors, and other equipment. They are effective in this application because they can measure levels with high accuracy while withstanding corrosive environments. The materials used to construct these sensors are carefully selected to resist chemical degradation. In this industry, these sensors are ideal for controlling the levels within reactors and other processing equipment, preventing overflows and dry conditions to enhance safety and reliability.

Industrial float level sensors' specifications, maintenance and repair

Specifications

Some key specifications of these float level sensors include:

• Measuring Range: The measuring range of these sensors refers to the level range they can measure. Typical ranges are from a few centimeters to several meters, depending on the application.
• Output Signal: These sensors are designed to provide various output signals, such as 4-20mA current output, voltage output, and digital communication protocols like Modbus or HART. This makes them easy to integrate into different control systems.
• Material Compatibility: These sensors are made from various materials, such as stainless steel, plastic, and glass. These materials are selected based on the requirements of the application and the industry to ensure durability and accuracy.
• Power Supply: The power supply for these types of equipment usually comes from a DC source. This is typically between 10V to 30V to ensure optimal functionality.
• Temperature: These sensors usually operate within -40°C to 100°C. However, this depends on the application, and some can handle even more extreme conditions.
• Pressure Rating: The sensors are designed and rated to withstand pressure, typically around 2 to 10 bar. Some are even higher for more rigorous industrial applications.

How to Replace and Maintain the Product

• Regular Calibration: Float level sensors are required to be frequently calibrated to maintain accuracy, especially after installation and during routine maintenance. This is primarily done by comparing the sensor output with a known reference level and adjusting as necessary.
• Cleaning: Cleaning the float and stem prevents buildup that can affect the sensor's performance. This is done based on the fluid characteristics, which can either be chemical cleaning or physical cleaning.
• Visual Inspection: A very robust and sound visual inspection is done to check for wear, corrosion, or damage to the sensor. This will include checking the float, stem, and guide wires, among others, for any signs of deterioration.
• Temperature and Pressure Checks: Ensure the sensor materials can continuously withstand the operating temperature and pressure conditions of the application. This is very important to help prevent sensor failure and damage.
• Replacement: Some sensors can be easily replaced. Maintenance personnel ensure they have the same type and model to guarantee continuity of level measurement. Before replacing, let the system stabilize to avoid measurement errors and overloading the new sensor with unnecessary information.

Common Problems and How to Fix Them

• Bumping: Bumping on float level sensors is the buildup of material, such as sludge or sediment, on the float, which prevents it from moving freely. This leads to inaccurate readings or complete failure of the sensor. Regular cleaning, using floats designed for the specific application, or installing a foam-breaking device to reduce the foam contact time with the float will prevent this problem from occurring.
• Electrical Interference: This problem affects the float sensor, especially in industries where heavy electrical equipment is in operation. Electrical interference can cause the sensor output to fluctuate, resulting in faulty readings. To prevent or mitigate this problem, buyers must ensure the sensors are installed away from sources of electrical interference and shielded wiring.
• Dry Running: These types of sensors, exposed to dry running conditions, can easily overheat and eventually get damaged. Industrial float level sensors are the only kind of level sensors affected by dry running conditions. Ensure there is always a minimum level of the medium being measured so that the float has something to ride on. Installing additional low-level alarms or failing them will create redundancy and help maintain the state where the sensor operates optimally.
• Float Leakage: Float level sensors are designed with floats. These floats, like any other equipment, can develop leaks over time. While usually made from durable materials, exposure to extreme temperatures and pressures can cause wear and tear, leading to leaks. In some cases, corrosion can also cause leaks. Either way, the only option is to replace the float. Regular inspections also help catch small leaks before they become big problems.

Q & A

Q1. What precision can industrial float level sensors achieve in their measurements?

A1. The accuracy level depends on the type of application and industry. They are generally accurate within 1-2% of full scale. This makes them very useful for real-time monitoring and control applications.

Q2. How do buyers select the suitable industrial float level sensor?

A2. Buyers should consider key factors like the temperature, pressure, and level range. They must also consider the nature of the liquid or slurry being measured and whether it's corrosive or viscous. These factors include the required measurement precision and the system where integrating the sensor is required. They should also consider budgetary factors and whether the selected sensors will be cost-effective in the long run.

Q3. How durable are these float level sensors?

A3. These float level sensors are designed to withstand harsh industrial conditions. They are made from robust materials such as stainless steel. Some even have a protective coating for additional shielding against corrosive substances. As mentioned before, while they are very durable, regular maintenance is required to keep them functioning optimally.

Q4. How can float level sensors be used in an IoT-enabled environment?

A4. The sensors can communicate their data to cloud-based platforms using wireless communication protocols. This will provide real-time monitoring and analytics. They also enable predictive maintenance by sending alerts before failures occur. In fact, integrating these sensors into an IoT framework allows users to remotely monitor and control their industrial processes. Further, it increases efficiency and decreases downtime.