Powder spraying system, powder spraying nozzle and method

A powder spraying system comprising:

• a) a source of dry powder;
• b) a spray nozzle;
• and
• c) a supply conduit connecting the source of dry powder with the spray nozzle;
• wherein the spray nozzle comprises:
• i) a nozzle body having a nozzle outlet;
• ii) a first conduit for dry powder;
• and
• iii) a second conduit for gas;
• the first conduit extending between a powder inlet in communication with the @ supply conduit and a powder outlet;
• the second conduit extending between a gas inlet and a gas outlet, the gas outlet being located in proximity to the powder outlet such that a gas flowing through the second conduit and out of the gas outlet produces a suction force at the powder outlet to promote flow of a dry powder through the first conduit and out of the powder outlet and the nozzle outlet;
• the powder outlet and the gas outlet being orientated to promote mixing of the gas with the dry powder;
• wherein the first conduit is a straight conduit between the powder inlet and the powder outlet;
• wherein the powder outlet is located at the nozzle outlet of the nozzle body such that an initial mixing of the gas with the dry powder occurs outside of the nozzle body;
• and wherein the nozzle body comprises one or more secondary gas outlets that are spaced from the nozzle outlet and are orientated to direct one or more secondary flows of gas to impinge on the flow of gas and dry powder exiting the nozzle outlet, the impingement being exterior the nozzle body and at a distance from the nozzle outlet.