Heating elements for polymerization oven
The task of the polymerization oven is to melt the powder paint particles applied to the product and ensure their curing. This usually takes 10-40 minutes at temperatures up to 200 ° C. Polymerization ovens are infrared and convective.
In the first case, heating occurs using infrared lamps. But such devices are quite specific and are used in highly specialized places.
The second ones – convective ones – provide heating with the help of heating elements. This is the most popular polymerization oven option among powder coating industries. They evenly and efficiently heat the oven, ensuring high-quality coating polymerization.
They will be discussed further. Let’s figure out how the heating elements are calculated for the polymerization oven, how they are arranged and how they work.
Heating element device
The heating element is a thin-walled metal tube with a high-resistance nichrome heater inside. The ends of this spiral are connected to a contact rod. And he, in turn, connects to the network.
Its shell, as a rule, consists of stainless steel or corrosion-resistant steel. Stainless steel increases the resource of heating elements. There are spiral ribs on the outside. They improve heat dissipation.
Heating elements can heat the oven up to 200 ° C within an hour. The oven does not heat up from the outside. Heating is controlled by thermostats, which are separately installed in the oven.
The heating devices require a voltage of 380 V. Although there are options that work at normal 220 V.
The calculation of heating elements for the polymerization oven is based on the length, width and height of the device, its thermal insulation and the temperature required for baking the paint. It is unlikely that it will be possible to determine the number of heating elements on your own. It is better to entrust this business to specialists who produce powder equipment, or professional electricians.
If you are going to buy separately heating elements for the polymerization oven, then you need to know exactly what power they should have and how many of them should be.
Location of heating elements
In the polymerization oven, heating elements are installed on the lid or at the bottom. They cannot be directly inside the oven. This can lead to problems. First, if there is a source next to the paint that heats up more than ⅔ of the ignition temperature of the paint. Most modern powders can ignite at 350 ° C. And the heating elements heat up to 400 ° C. And if the heating devices are inside, then they will have to be turned off regularly. And this is an inefficient use of equipment.
Secondly, if paint accidentally gets on them, it will burn. The paint will deteriorate, and the heating elements themselves may fail.
Well and more. The heating devices remain hot for some time after the end of work. And if there is a manual oven in production, then the painters can accidentally burn themselves.
The work of heating elements
So, heating elements are needed to warm up the polymerization oven and bake paint in it. We have already dealt with this. And now about how they work.
The painter must load the product to be painted into the device. Then he turns on the oven and the thermoblock starts. Heating elements begin to heat up the oven. The thermostat controls the temperature in the device. After the oven has heated up to 140 ° C, the extractor hood is switched on every 5 minutes for 10 minutes. When the oven heats up to the required temperature, the heating elements are turned off and the time relay is turned on.
As a rule, the calculation of the power of the heating elements and their location are worked out by engineers during the design of the polymerization oven. It is better not to design heating elements yourself, as they can cause serious problems. The price of the entire polymerization oven depends on how many heating elements there will be and with what power they will work.
