Powder chamber for an air-polishing device and air-polishing device

Powder chamber for an air polishing device, extending from a top end to a bottom end along an axis, for breaking down the tendency of the powder to be packed during falling down along a direction of gravitation, said powder chamber comprising:

• at least two wall sections,
• wherein a first wall section forms a first angle with respect to the axis and the first angle is within a range of 20-70°,
• wherein a second wall section forms a second angle with respect to the axis and the second angle is within a range of −70 to 20°,
• wherein the angles are measured in a measuring direction from the axis to the appropriate wall section in such a manner so that acute angles are obtained,
• wherein the second wall section is arranged below the first wall section,
• wherein the second angle is smaller than the first angle;
• wherein the bottom end comprises an air inlet, the air inlet being formed as nozzle to conduct air into the powder chamber,
• wherein a bottom plate is arranged at the bottom of the powder chamber, wherein the nozzle extends from the bottom plate into the powder chamber;
• wherein the air inlet extends into the powder chamber,
• wherein an outlet is arranged at the top end of the powder chamber to transport the powder gas mixture to the air polishing device, comprising a third wall section that forms a third angle with respect to the axis,
• wherein the third angle is bigger than the second angle,
• wherein the third wall section is arranged below the second wall section wherein the first angle and/or the third angle is at least 15°,
• wherein the outlet being configured to bring an air-powder-mixture to the air polishing device, wherein the outlet is spaced from the inlet, and
• wherein a Venturi-tube is arranged at a side of the powder chamber and wherein the powder chamber is filled with low abrasive powder, wherein a grain size of the powder is smaller than about 100 μm on average.