Controlled dispersion multi-phase nozzle and method of making the same

• US 20060065869A1
• Filed: 05/12/2005
• Published: 03/30/2006
• Est. Priority Date: 05/13/2004
• Status: Active Grant

• Current Assignee: Caldera Engineering, LC
• Original Assignee: Caldera Engineering, LC
• Inventors: Chipman, Stephen R., Robison, Jeffrey C., Luque, Michael R., Smith, Craig C., Pieterse, Herman
• Granted Patent: US 7,237,574 B2
• Time in Patent Office: Days
• US Class Current: 251/118
• CPC Class Codes: F16K 47/16 the throttling member being a cone

Abstract

A nozzle design and method for designing such a nozzle being adapted for three phase slurry flow from the choke into the flash tank during pressure let-down in autoclave mining operations that uses a selection of the expansion ratio in the choke to select a nozzle dispersion angle to select a spread of the flow over the slurry pool in the flash tank, to generally maximize the use of the pool for energy dissipation without causing undo wear and tear on the tank walls.

Claims

1. A method for defining the dispersion angle of a choke nozzle, comprising:

(A) defining slurry properties;

(B) defining state of upstream slurry;

(C) determining state of downstream slurry;

(D) determining upstream slurry enthalpy and entropy;

(E) determining slurry characteristics for a pressure state of interest;

(F) determining the area ratio for a pressure state of interest;

(G) determining velocity and Mach number for the slurry at each pressure state of interest;

(H) modeling the slurry expansion; and

(I) selecting an area ratio for a desired choke nozzle expansion angle.

4. A method for defining the dispersion angle of a choke nozzle, as recited in claim 1, wherein said defined slurry properties are properties of said slury required for the modeling of said slurry as a homogeneous equilibrium three phase fluid.

5. A method for defining the dispersion angle of a choke nozzle, as recited in claim 1, wherein said defining state of upstream flurry is defined by a characteristic selected from the group consisting of pressure, temperature, steam fraction and quality.

6. A method for defining the dispersion angle of a choke nozzle, as recited in claim 1, wherein said determining state of downstream slurry is indirectly defined by the conservation laws.

7. A method for defining the dispersion angle of a choke nozzle, as recited in claim 1, wherein said determining slurry characteristics for a pressure of interest further comprises using the conservation of energy, the second law of thermodynamics and slurry characteristics.

8. A method for defining the dispersion angle of a choke nozzle, as recited in claim 1, wherein said determining the area ratio for a pressure state of interest further comprises taking an inverse ratio of the corresponding mass fluxes.

9. A method for defining the dispersion angle of a choke nozzle, as recited in claim 1, wherein said modeling the slurry expansion, further comprises modeling as selected from the group consisting of an isentropic expansion and a non isentropic expansion with an entropy increase to model dissipation.

2. A valve having a multi-phase nozzle, for use with a slurry tank that contains a slurry pool, comprising:

a valve having a choke configuration;

said valve further comprising a nozzle and a plug head capable of being modulated to control flow rate by changing a throat area; and

an expansion area downstream of said throat area, said expansion area being increased by an expansion angle sufficient to maintain a dispersion flow angle from an exit of said nozzle so as to spread slurry flow over the slurry pool so that a large portion of the surface area of the pool is used while minimizing contact with the tank walls and wherein said expansion angle is determined by the method, further comprising;

(A) defining slurry properties;

(B) defining state of upstream slurry;

(C) determining state of downstream slurry;

(D) determining upstream slurry enthalpy and entropy;

(E) determining slurry characteristics for a pressure state of interest;

(F) determining the area ratio for a pressure state of interest;

(G) determining velocity and Mach number for the slurry at each pressure state of interest;

(H) model the slurry expansion; and

(I) select an area ratio for a desired choke nozzle expansion angle.

3. A choke comprising:

a nozzle having an expansion angle determined by the method further comprising;

(A) defining slurry properties;

(B) defining state of upstream slurry;

(C) determining state of downstream slurry;

(D) determining upstream slurry enthalpy and entropy;

(E) determining slurry characteristics for a pressure state of interest;

(F) determining the area ratio for each pressure state of interest;

(G) determining velocity and Mach number for the slurry at each pressure state of interest;

(H) model the slurry expansion; and

(I) select an area ratio for a desired choke nozzle expansion angle.