What Is An Over Temperature Controller?
Dec 27, 2023| What is an over temperature controller?
**Introduction
An over temperature controller is a device that is used in various industrial processes to control or limit system temperature to a safe level. It monitors the process temperature and sends signals to the control system to control the heater power to control the temperature within a safe range.
Over temperature controllers are vital in industrial processes as they ensure safety and protect equipment from overheating. In this article, we will discuss the various types of over temperature controllers, their working principle, and applications.
**Types of over temperature controllers
There are different types of over temperature controllers available in the market. They differ in terms of their working principle and applications. Here are the common types:
1. Thermostatic controllers: These devices use a bimetallic strip that expands or contracts depending on the temperature change. When the temperature rises above the set limit, the bimetallic strip expands and triggers the switch to turn off the heater to reduce the temperature. Similarly, when the temperature falls, the bimetallic strip contracts, and the switch is turned on.
2. Thermocouple controllers: These are electronic devices that use a thermocouple sensor to measure the temperature. Thermocouples generate a small voltage when exposed to temperature variations. These devices measure the voltage signal and convert it to temperature using a temperature controller. When the temperature exceeds the set limit, the controller sends a signal to the switch to turn off the heater.
3. Resistance temperature detectors (RTD) controllers: These are also electronic devices that use an RTD sensor to measure temperature. RTD sensors measure electrical resistance in response to temperature changes. The controller measures the resistance and converts it to temperature using a temperature controller. When the temperature exceeds the set limit, the controller sends a signal to the switch to turn off the heater.
**Working principle of over temperature controllers
Over temperature controllers work based on the principle of feedback control loop. The controller measures the process temperature using a sensor and compares it with the set temperature. If the measured temperature exceeds the set limit, the controller sends a signal to the switch to turn off the heater.
The controller continuously monitors the process temperature and adjusts the heater power accordingly to maintain the temperature within a safe range. It also takes into account the heating and cooling dynamics of the process to prevent temperature overshoot or undershoot.
**Applications of over temperature controllers
Over temperature controllers are widely used in various industrial processes that involve heating. Here are some common applications:
1. Furnaces: Over temperature controllers are used in furnaces to control the furnace temperature and protect it from overheating.
2. Hot water systems: Over temperature controllers are used in hot water systems to maintain the water temperature within a safe range and prevent scalding.
3. Chemical reactors: Over temperature controllers are used in chemical reactors to prevent exothermic reactions that can result in runaway reactions and explosions.
4. Industrial ovens: Over temperature controllers are used in industrial ovens to control the oven temperature and prevent overheating of the materials being processed.
5. Heat exchangers: Over temperature controllers are used in heat exchangers to control the temperature of the heat transfer fluid and prevent thermal degradation.
6. Power plants: Over temperature controllers are used in power plants to control the temperature of the steam and prevent damage to the turbine.
**Conclusion
Over temperature controllers are important devices in industrial processes as they ensure safety and protect equipment from overheating. There are different types of over temperature controllers available in the market that differ in terms of their working principle and applications.
The principles of feedback control loop are used in over temperature controllers to maintain the process temperature within a safe range by adjusting the heater power. Over temperature controllers are widely used in industries like chemical, power generation, and food processing.
Overall, over temperature controllers are essential components in industrial processes that involve heating, and their selection depends on the specific application requirements.