Let's break it apart from the name
The compensator is the expansion joint, and they are the same thing. Non-metallic compensator, to put it bluntly, is an expansion joint made of flexible materials such as fabric fiber and rubber. The kind used in the flue of electrolysis plant, which is specially used to deal with the thermal expansion and contraction and pipe displacement caused by high temperature and corrosive flue gas. You run to the scene and take a look, and the bulging, cloth-bag-like thing at the flue interface is it. Don't underestimate this thing. If you choose the wrong thing or use it out, you will lose tens of thousands of dollars at a time of downtime.
Why must electrolysis plants use non-metals?
The metal compensator can't bear it at all under this working condition-the flue gas contains hydrogen fluoride and sulfur dioxide, and the metal bellows will corrode and perforate in a few months at high temperature. I have seen a case where a metal bellows was installed in an electrolysis plant. In less than half a year, yellow smoke began to emit from the weld. When I removed it, it was as thin as paper. Non-metallic multi-layer composite structures, such as fluororubber + glass fiber + polytetrafluoroethylene, can not only withstand the temperature to 300℃ or even higher, but also withstand acid-alkali corrosion. Moreover, it has good elasticity, large compensation amount, and can easily handle the thermal expansion and contraction of the pipeline. Do you say, is it comparable to metal?
Structurally, it is completely different from the metal compensator
There is no ripple, but it is the bending of the fabric fiber layer and the elastic deformation of the rubber layer to absorb the displacement. Typical products like this siteNon-metallic expansion joint (fabric fiber expansion joint)AndRectangular non-metallic expansion joint, the rectangular section just matches the rectangular flue of the electrolysis plant, the installation flange connection, and the middle is a sandwich fabric. A guide tube has to be added inside to prevent high-speed smoke from directly washing the fabric layer-this point is ignored by many novices, and the consequence is that the fabric layer is blown away and has to be replaced in three months.
Type selection is a technical job
Temperature, pressure, media composition, flue size, required compensation amount, a parameter wrong will wait for air leakage. For example, if the temperature exceeds 250℃, conventional rubber will not work, and fluororubber or pure PTFE layer will be used. At this timeRubber PTFE compensatorAndPTFE compensatorIt would be more appropriate. The pressure is generally low, but the flue of the electrolysis plant runs under negative pressure, so the sealing requirements are high, so the strips and sealing rings should be carefully selected. Two days ago, I met a customer, and randomly bought a general-purpose corrugated expansion joint and installed it. When the negative pressure was sucked, the sealing ring was directly deflated, and the yellow smoke came out, so I had to stop and change it. So don't try to save trouble, the parameters have to be checked one by one.
There is a pit in installation and maintenance that many people step on
Don't hurry to dismantle the limit screw when the non-metallic compensator leaves the factory. It is used to prevent excessive stretching during transportation and installation. After all the pipes are in place and the bolts are tightened, the screw is loosened to allow the compensator to expand and contract freely. This order is reversed, and the compensator is pulled and deformed before it is used. In addition, check the fabric layer regularly for bulging and cracking, especially on the side near the electrolyzer. If you find small damage, make up it in time. Don't wait until the whole flue emits yellow smoke before repairing it. At that time, the downtime loss will be great. It is recommended to inspect once a quarter, and scan the surface temperature with an infrared thermometer to see if there are any local overheating spots-this can find the problem of falling off or internal blockage of the guide tube in advance.