US 12,280,468 B2
Method and design for productive quiet abrasive blasting nozzles
Christopher Sullivan, Honolulu, HI (US)
Assigned to KENNAMETAL INC., Latrobe, PA (US)
Filed by Kennametal Inc., Latrobe, PA (US)
Filed on Mar. 13, 2020, as Appl. No. 16/819,035.
Application 16/819,035 is a continuation in part of application No. PCT/US2019/065783, filed on Dec. 11, 2019.
Application PCT/US2019/065783 is a continuation in part of application No. 16/216,972, filed on Dec. 11, 2018, granted, now 11,383,349.
Application 16/819,035 is a continuation of application No. 16/216,972, filed on Dec. 11, 2018, granted, now 11,383,349.
Prior Publication US 2020/0282517 A1, Sep. 10, 2020
This patent is subject to a terminal disclaimer.
Int. Cl. B24C 5/04 (2006.01); B05B 1/00 (2006.01); B24C 1/00 (2006.01); B24C 3/02 (2006.01); B24C 7/00 (2006.01)
CPC B24C 5/04 (2013.01) [B05B 1/002 (2018.08); B24C 1/00 (2013.01); B24C 3/02 (2013.01); B24C 7/0046 (2013.01); B24C 7/0053 (2013.01); B24C 7/0061 (2013.01)] 29 Claims
OG exemplary drawing
 
1. A productive abrasive blasting nozzle, comprising:
a converging portion having a converging internal diameter;
a throat having an internal diameter connected to the converging portion, wherein the throat has a length extending from a beginning of the throat to an end of the throat;
a diverging portion having an internal diameter connected to the throat; and
a straight portion having an internal diameter connected to and immediately following the diverging portion;
wherein the straight portion has a length such that a velocity of gas exiting the blasting nozzle is reduced by at least 30% relative to the blasting nozzle with the straight portion removed, when operated with a predetermined gas and particle mix and pressure;
wherein, in operation, fluid flows through the converging portion, the throat, the diverging portion, and the straight portion, in that order; and
wherein the length, L, of the straight portion is at least L*, as given by the following equation:

OG Complex Work Unit Math
where D is a diameter of the straight section, M is the Mach number of the fluid at an entrance to the straight portion, f is the average friction factor of the straight portion, fabrasives is the friction factor of the particles in the fluid flow, and γ is the specific heat ratio of the fluid flow, for a predetermined gas and abrasive particle mixture.