Why bimetallic strip use overheating protection not for use heat detection?
 |
| bimetallic strip over heating protection and detection [figure 1] |
 |
| bimetallic strip over heating protection and detection [figure 2] |
What is bimetallic strip
The bimetallic strip usually acts on the coefficient of Contraction and expansion of metal. In this case, two different metals are joined together by riveting or welding. We know different materials have different coefficients of expansion. An example of a bimetallic strip made of aluminum and steel . Expansion of aluminium is more than steel . Aluminum expansion per degree C is 24×10^-6 °C . and aluminum is 13 × 10^-6 °C. If applied heat the less expansion materials bend the whole strip. Using this function we can make any material heat effective or heat sensitive. This is the brief explanation of Bimetallic strips.
Application of Bimetallic strip
Sometimes it is used for over heat protection or heat detection .
Overheating protection Application
Geyser or water heater,Electric iron, Refrigerator,heater etc
Heat Detection
In the electrical control panel use a thermostat for detection of any fire Hazards . This thermostat is made of bimetallic strips.
How both metal join each other
Many ways to join Bimetal ,The two ends of the bimetal are riveted to join the two bimetals together.
In addition, laser welding spot welding is done by riveting the bimetal.
The most effective of these two riveting processes is laser welding spot welding.
Why bimetallic strip suitable for detection
When heat is applied, the metal that expands more and bends.When the heat is applied and stopped, the metal returns to its previous state.
Bimetallic strips are usually made of copper steel , steel brush, or aluminum and steel material. Depending on the nature of the metal and bimetallic strip, a device called a thermostat was created .
This device is used for overheating protection. This device is commonly used for heat control in geysers , washing machines ,refrigerators, tube light starters ,heaters and other heating applications. On the other hand, heat detection is done by a heat sensor. It must be used in school, college, office, hospital etc .
This can be said in terms of the question bimetallic strip operating temperature is 250°C or 482° F. This information proves that the fire will spread a lot as long as the bimetallic strip is sensed.For that it is not used in case of heat detection.
How bimetallic strip operate specified temperature
Here use a spring which can control the fixed point. When system need low temperature . The spring arrangement decreases the gap between the bimetallic strip and the fixed point. When system needs medium temperature the spring Increase the gap between bimetallic strip and fixed point more the required low temperature. Again when system need to operate higher temperature the release the spring then decrease the gap between bimetallic strip and fixed point on maximum position. Then higher heat will release. This arrangement is mostly use in electric iron ,geyser or water heater , electric kettle, etc application.
But electrical control panel maintain the gap between bimetallic strip and fixed point as low as possible. Because electrical hazards will be more dangerous than other hazards, fire will within a second take a turn that cannot be controllable. Here we use a temperature sensor as a supporting system . If any system malfunctioned then other system can detect the hazards.
Nowaday advance fire protection system
When any system tends to any fire Hazards . Here we need a minimum temperature for dictation. The bimetallic strip failed to operate at minimum temperature. When fire Hazards will excessive then the bimetallic strip will react. This is not an efficient way to fire detection.
Here many type of advanced electronic system and Sensor . This operation will be done in an efficient way. Here we can regulate the minimum react temperature value. And Control other prevention Equipments. Such as automatic water spray, fire extinguisher gas etc. The will finish when try to rise.
We already discussed this fire Hazards prevention sensors. Here some equipment is the direct temperature of the atmosphere . And some of them they are detect smoke.
So it is dangerous. Since the bimetallic strip operates at higher temperatures, it is suitable for use in temperature control. Temperature control works well with a bimetallic strip.
Usually the device that should be used for heat detection purposes needs to be highly sensitive.Sensors are used for heat detection. It continues to record the room temperature and provides an integrated signal to the output alarm circuit.
Generally speaking, it sends an alarm signal to the output when the temperature rises above the room temperature in a room and it continues to rise.
Heat sensors as well as smoke sensors are used to make the fire extinguisher system more sensitive.
Bimetallic strip use of power system
Bimetallic strip or thermostat use Electrical substation meny devices. We know in electrical substations heat rising means fault . Mainly it can use circuit breaker and Transformer. When Transformer leakage current is rising then that leakage current or leakage flux try to
Transformer wall or cabinet. Due to the interaction of leakage current heat can be developed in Transformer. And it can rising rapidly.
The cause of leakage current is any malfunction in core or winding or any failure of insulation. This rising temperature is dangerous for Transformer. Rising supply current is measured by many types of instruments but leakage current Detection does not have any equipment .
Due to rising leakage current heat will increase . We detect the Heat by thermostat . When this occurs, the thermostat send a trip signal to the panel room. The Transformer take shutdown for fault troubleshooting.
Same way when a circuit breaker trips, the circuit heat will develop. Then That heat does not make a huge fire hazard . Thermostat is use here.
The thermostat send a trip signal to panel room . Then change the supply through duplicate bus . And which circuit breaker detected rising temperature. That circuit breaker take to under maintenance.
Conclusion
Bimetallic strip efficiently work on overheating protection or temperature protection. So Nowday use advance heating protection system have some malfunction due compactness. Here Bimetallic strip is reliable for over heat protection with less price .
It means any over heat protection system Bimetallic strip is only way to reduce the price of protection system. bimetallic strip cannot improve a fire extinguishing system.For this bimetallic strip is not suitable for heat detection.
Conclusion
Bimetallic strip efficienctly work on over heating protection or temperature protection. So Nowday use advance heating protection system have some malfunction due compactness. Here Bimetallic strip is reliable for over heat protection with less price . It means any over heat protection system Bimetallic strip is only way to reduce the price of protection system. bimetallic strip cannot improve a fire extinguishing system.For this bimetallic strip is not suitable for heat detection.
--------------------------------------------------
Other posts
Can a DC Generator utilise Wastage Energy in a Traction System
0 Comments