The varnish removal procedure is performed in a technological apparatus especially designed for this process; the incineration takes place one batch at a time and takes 50 to 90 min. in the following order:
The metal parts we wish to clean are placed in a basket which is then immersed into the hot fluidizing chamber. The coating removal process takes place in two stages. The first stage is decomposition (vaporising) of the combustible part of the varnish from the hangers in a bed with a floating layer. The bed is composed of silicium dioxide sand particles of a particular size, heated to approximately 420 ºC. Through the layer of silicium dioxide grains of sand a mixture of air and natural gas is passed, having two functions. The first is preserving the bed's floating layer which is assured by a ventilator with the necessary mixture flux and the second function is maintaining the bed temperature at the required level.
The incombustible part of the varnish remains partly as ash on the hangers and the remaining part is carried forward by the air flux to the secondary chamber. The vaporised organic material also proceeds from the bed to the secondary chamber, where it is incinerated. The secondary chamber temperature is between 850 and 900 ºC. There is a series of burners that maintain the temperature in the secondary chamber.
After exiting the secondary chamber the gases proceed to a dust particle removing device with ceramic filters. The dust particle removing device eliminates dust that is collected in a container.
The purified exhaust gases are ventilated through the exhaust into the atmosphere. After the varnish removal procedure the hangers are washed with water under high pressure and thus all ash particles are removed.
To the DINAMEC apparatus a heat exchange system was added for exploiting the excess heat that is used for stabilizing dust paint waste.
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