Device for conveying fluid

1. A device for conveying coating powder comprising:

a conveying chamber,

an inlet valve, which is located in the direction of flow, upstream of the conveying chamber,

an outlet valve, which is located in the direction of flow, downstream of the conveying chamber,

an injector, including a suction duct which is permanently connected to the conveying chamber in an outlet area of the conveying chamber and an injector outlet which is connected to an outlet of the outlet valve, and

an air duct, which is connected to the conveying chamber, so that exhaust air (AL) can be blown into the conveying chamber,

wherein the air duct for the exhaust air (AL) opens into the conveying chamber in an entry area of the conveying chamber, and

wherein the inlet valve and the outlet valve are pinch valves driven by compressed air.

2. The device according to claim 1 ,

further comprising a compressed air duct for dosing air (DL), and the compressed air duct is connected with the outlet of the outlet valve.

3. The device according to claim 2 ,

wherein the injector comprises an injector nozzle, which is provided with injector nozzle air (TL) via a connection.

4. The device according to claim 3 , further comprising a controller including control connections of the inlet valve and outlet valve, the control connections including a control connection for the dosing air (DL), a control connection for the injector nozzle air (TL) and a control connection for the exhaust air (AL) located on a front face of the device for conveying fluid.

5. A system for conveying fluid comprising the device according to claim 4 , wherein:

the control connection for the dosing air includes a control valve for the dosing air,

the control connection for the exhaust air includes a control valve for the exhaust air,

the control connection for the injector nozzle air includes a control valve for injector nozzle air, and

the controller controls the inlet valve, the outlet valve and the control valves.

6. The device according to claim 2 ,

further comprising a non-return valve, which is connected to the compressed air duct for the dosing air (DL) to prevent return flow of the dosing air.

7. The device according to claim 1 ,

wherein the air duct comprises a flow barrier for the coating powder to be conveyed.

8. The device according to claim 1 ,

wherein an insert is provided in order to increase the volume of the conveying chamber.

9. The device according to claim 1 ,

wherein the suction duct of the injector meets the conveying chamber at an acute angle (α).

10. A method for operating a device for conveying coating powder comprising:

in a first phase, opening an inlet valve connected to a conveying chamber and closing an outlet valve connected to the conveying chamber,

conveying the coating powder into the conveying chamber,

providing an injector in an outlet area of the conveying chamber with injector nozzle air (TL) through a suction duct which is permanently connected to the conveying chamber to create a vacuum in the conveying chamber, wherein the injector nozzle air TL flows through an injector outlet which is connected to an outlet of the outlet valve,

in a further phase, closing the inlet valve and opening the outlet valve, and blowing exhaust air (AL) into the conveying chamber to convey the coating powder out of the conveying chamber

wherein the exhaust air (AL) is blown into an entry area of the conveying chamber, and

wherein the inlet valve and the outlet valve are driven by compressed air.

11. The method according to claim 10 , further comprising: holding constant by means of a controller the overall amount of air, which comprising the exhaust air (AL), the injector nozzle air (TL) and dosing air (DL).