Kayden's CLASSIC 800 Series thermal flow, level, and interface switches and transmitters detect and monitor the flow rate or level/interface of a liquid or gas in a system based on the principle of thermal dispersion or thermal differential.
The CLASSIC 800 Series operates by measuring the amount of heat carried away by the process media as it moves past a heated temperature sensor, compared to a reference sensor that measures the ambient temperature of the process media. The difference in temperature between these two sensors is used to determine the flow rate, interface, or point-level condition.
Kayden calorimetric flow and level switches, also referred to as thermal flow monitors or level monitors function as follows:
Heating Element
The thermal switch has a heating element (or sensor) that is warmed to a certain temperature above the process media's temperature.
Temperature Sensors
Alongside the heating element, the device includes temperature sensors. One sensor measures the temperature of the heated element, while another measures the ambient temperature of the process media.
Flow Detection
When there is no flow or the flow is below a certain threshold, the temperature differential between the heated sensor and the ambient process media is more significant. As the flow rate increases, the process media carries away more heat from the heated sensor, reducing the temperature difference between the heated element and the reference element.
Level Detection
When the level of the process media rises and comes into contact with the heated probe, the probe cools down due to the increased heat dissipation caused by the cooler process media. Conversely, when the level drops and the probe is exposed to air, the probe's temperature rises because air's thermal conductivity is lower, and it dissipates less heat.
Signal Output
The switch translates the temperature difference into an electrical signal that can trigger an alarm, activate a relay, or send a signal to a control system, indicating whether the flow rate is above or below a preset threshold.
Thermal flow and level switches are known for their simplicity, reliability, and the ability to work without moving parts, which minimizes maintenance and the risk of mechanical failure.
Kayden's thermal switches are highly versatile and can be used in various applications, including cooling circuits, pump protection (to ensure there is flow in a system and prevent dry running), and process control in industries such as chemical manufacturing, pharmaceuticals, and food and beverage production.
Thermal level switches can be used for level detection in a wide range of applications, including overfill protection, and ensuring proper filling or emptying of tanks and containers. These monitors are suitable for use with various materials, including liquids and slurries, and can operate in challenging conditions, such as high pressure and temperature environments.
Kayden's thermal dispersion flow, level, and interface sensing technology provides accurate results to achieve highly reliable and repeatable setpoint detection in a wide range of demanding applications, all while providing a long service life.