Getting To Know Thermal Spray Powder Feeders
Feeders, in the thermal spray industry, are essential equipment that is responsible for supplying the coating material. These feeders are able to feed materials in either wire form or powder form. In this post, the spotlight will be on powder-type materials. With that in mind, the powdered coating materials will be sent to the gun to facilitate a flawless application process.
Thermal spray powder feeders can vary according to thermal spray process, coating material as well as the scope and scale of your production run. All in all, the feeders are designed to increase efficiency of coating processes, enhance safety and more. The two most common powder feeders are fluidized bed and rotating disk powder feeders. Let’s take a closer look at their individual designs:
About Fluidized Bed Thermal Spray Powder Feeders
What is a fluidized bed? For starters, fluidized beds are a result of a phenomenon called fluidization. Let’s pretend that you have a certain quantity of a solid particulate substance in a holding vessel. When you place it under appropriate conditions, you can cause the fluid or solid mixture to behave as a fluid. That’s impressive. How? Pressurized fluid is often introduced through the particulate medium. The medium will begin to have similar characteristics and properties of normal fluids.
Another thing to note is that a portion of the carrier gas is utilized to create back pressure that allows the powder to become fluidized with the carrier gas. Theoretically speaking, this ensures even flow and size distribution of the powder as it is drawn up into the powder pickup shaft. With converging/diverging internal design of the shaft (pickup), it can draw the powder into the gas stream of the carrier and deliver it to the gun with ease.
When fluidized bed powder feeders are properly maintained, the vast array of pinch valves and hoses found internally will cause no problems.
About Rotating Disc Thermal Spray Powder Feeders
In rotating disk powder feeders, a rotating disk (its name is rather self explanatory of the design’s operation) is the main component that feeds the powder. A large number of small holes or slots can be found on the disk, and they rotate in a circle as well. You will notice that the holes rotate underneath the hopper; the hopper holds the powder. The powder will be fed through the holes and rotate past the powder discharge tube of the powder hopper.
Once it successfully rotates to another discharge hole, the powder drops down into the carrier hose. The powder carrier gas will transfer the powder to the gun. All in all, the rotating disk powder feeder design is a rather simple one, is reliable, and pretty easy to maintain. You just need to take note of the various parts that are prone to wearing. These parts include:
- Felt seals
- Disk seals
- Metal rotating disks
If the maintenance procedures are performed correctly, you can get these feeders to operate without problems for many years.
Want to find out more about the thermal spray powder feeders A&A Coatings is using? Contact us today for more information!