Dense phase powder pump

A dense phase powder pump for conveying coating powder from a first powder reservoir to a downstream second powder reservoir or a downstream powder spray coating gun, wherein the dense phase powder pump comprises a powder conveying chamber which is fluidly connected or connectable to the first powder reservoir via a powder inlet and to the second powder reservoir or the downstream powder spray coating gun via a powder outlet, wherein at least one powder inlet valve is provided at the powder inlet and at least one powder outlet valve is provided at the powder outlet,

• wherein the at least one powder inlet valve and the at least one powder outlet valve are each configured as a pinch valve comprising a flexible elastic hose as a valve channel that can be squeezed by actuating compressed air in a pressure chamber surrounding the respective flexible elastic hose in order to close the respective valve, and are each configured to return to an initial state in the absence of a differential pressure to an ambient pressure in the pressure chamber surrounding the respective hose, said initial state of the flexible elastic hose defining the corresponding open state of the respective valve,
• the dense phase powder pump characterized in that:
• the at least one powder inlet valve and the at least one powder outlet valve each exhibit a flow cross section in the respective open state having a two-dimensional area less than a two-dimensional area flow of a flow cross section of the powder conveying chamber, where a flow cross section of any part is defined as a cross section taken through a plane orthogonal to a flow direction through that part;
• the at least one powder inlet valve exhibits a flow cross section in the respective open state having a two-dimensional area which corresponds to at least 35% of the two-dimensional area of the flow cross section of the powder conveying chamber;
• and
• the dense phase powder pump is configured as a single-chamber dense phase powder pump and comprises only one single powder conveying chamber for conveying coating powder.