Modern people have higher and higher requirements for t […]
Modern people have higher and higher requirements for the quality of life, and accordingly, the standards for faucets are getting higher and higher.
The faucet is constantly evolving to meet the modern bathing requirements. The manual thermostat faucet from the original hot and cold double water pipes has been developed as a constant temperature faucet that can automatically discharge constant temperature water without manual adjustment.
When it comes to constant temperature, from a professional point of view, it is to maintain a constant temperature under certain circumstances. The constant temperature faucet is to let you bathe at a constant water temperature for a comfortable bath.
Constant temperature principle of thermostat
The constant temperature faucet can automatically balance the water pressure of cold water and hot water in a short time by the constant temperature regulating valve core of the faucet to keep the water temperature stable, and no manual adjustment is needed.
What is important for this constant temperature is actually a thermostatic valve core part that is "memorized" at the temperature - shape memory alloy (hereinafter referred to as SMA) spring.
The shape memory alloy spring made of nickel-titanium (Ni-Ti) alloy has an effective operating temperature range of 0 ° C to 100 ° C.
In the SMA thermostatic valve core, the shape memory alloy spring itself acts as both a temperature sensing element and a push piston to regulate the mixing of hot and cold water, and the mixed water can also pass through the spring, thus saving valuable space. Make the thermostatic spool more compact.
The SMA thermostatic spool has a very fast response speed and the temperature transient override can be controlled below 2 °C. Moreover, the SMA thermostatic valve core is extremely sensitive in response to around 40 ° C, which can meet the needs of users for stepless fine adjustment.
This kind of thermostatic valve core has been produced by Japanese manufacturers before, but now domestic manufacturers are successfully breaking through this technology, breaking the technical barriers mainly relying on foreign countries. It is the first breakthrough in shape memory alloy spring technology in the industry. Companies with a temperature change of Af ± 1 °C (domestic phase change temperature standard is only ± 5 ° C).
As a core device, the SMA thermostatic spool has been widely used in constant temperature water heaters and thermostats/showers. Shape memory alloy springs, which are important parts of SMA thermostatic valve cores, are also increasingly used in the field of constant temperature and temperature control.
The history of thermostats
We know that the earliest hot and cold water mixing faucet is a double knob faucet. The user needs to turn the knob for controlling cold water and hot water to adjust the water intake of the hot and cold water, so as to mix it into warm water requiring temperature;
Another type of hot and cold water mixing faucet is a single handle faucet. Its core is a ceramic piece temperature regulating valve core. The left and right swinging handles of the user can adjust the temperature of the mixed water, and the up and down swinging handle can adjust the amount of water. However, when the water pressure of hot or cold water suddenly changes, or when the temperature of the hot water suddenly changes, the above two types of mixing faucets must be manually adjusted to re-adjust the water temperature.
Now there is a constant temperature faucet that does not need manual adjustment. It first appeared in Europe, and the thermostating method uses different thermostatic valve cores:
The first generation of thermostatic spools used paraffin thermostats.
The paraffin temperature sensing module works by pouring high-purity special paraffin into a small brass container with a rubber sensor strip. Due to the change of water temperature, the volume of paraffin in the container also shrinks, and then the sensing piece of the container mouth drives the spring to push the piston to adjust the mixing ratio of the hot and cold water.
The second generation of thermostatic spools uses shape memory alloy (SMA) springs (described above).
With the extensive use of shape memory alloys and the continuous breakthrough of their technology, this thermostatic valve core has been widely used in China to adjust the temperature of the bathroom water pipes, so as to be comfortable to bathe.
Since the thermostatic spool is a very precise device, the internal processing of the thermostatic faucet housing with the thermostatic valve core is very precise, whether it is the first or second generation thermostatic valve core. The tolerances of all internal machining dimensions should be The tolerance is within ±0.01mm, and the tolerance of important dimensions must be controlled within ±0.005mm.
The recommended inlet water pressure requirement for general constant temperature faucet: 0.05MPA-0.59MPA, inlet water temperature requirement: the inlet temperature of hot water should be kept higher than the set temperature by more than 7 degrees, and it is better to continue to provide temperature continuously. Hot water above 55 degrees.
Thermostatic faucets/showers are suitable for use in showers in homes, hotels, public baths, and in places where the water pressure is constantly changing, such as hairdressers.