WO2019067485A2 - Apparatus for mixing fluids and solids with separate injector port - Google Patents

Abstract

Systems and methods for mixing fluids such as cement and water are disclosed. A cement mixer has a chute and an inducer configured to deliver a dry, powdered material such as cement into a mixing chamber. The inducer can rotate to prevent clumping and to urge the material into the mixing chamber. A fluid inlet can deliver fluid to a volute chamber configured to deliver a substantially uniform fluid curtain into the mixer. The inducer causes the dry material to move radially outwardly onto an interior surface of the fluid curtain to promote uniform mixing of the fluid and the dry material

Description

APPARATUS FOR MIXING FLUIDS AND SOLIDS WITH SEPARATE INJECTOR PORT

CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present document is based on and claims priority to US Provisional Patent

Application Serial No. : 62/563,135 , filed September 26, 2017, which is incorporated herein by reference in its entirety

BACKGROUND

[0002] Many applications in the oil and gas industry call for the use of cement. Cement can be a very useful substa nce and can provide a barrier, a seal, or structural support. Mixing a nd depositing cement can be a challenge, especially when the desired location is down a well. The approaches, techniques, and structures of the present application help to address some of the difficulties presented by mixing cement.

BRIEF DESCRIPTION OF THE FIGURES

[0003] Figure 1 is a cross sectional illustration of a cement mixing apparatus according to embodiments of the present disclosure.

[0004] Figure 2 is an isometric cut-away illustration of a cement mixing apparatus according to embodiments of the present disclosure.

[0005] Figure 3 is an isometric view of a mixer assembly having a plurality of vanes according to embodiments of the present disclosure.

[0006] Figure 4 shows an embodiment according to the present disclosure in which the vanes are eliminated and the shape of the volute liquid port are used to impart the desired movement to the material.

[0007] Figure 5 is a fluid diagram achieved using computational fluid dynamics according to embodiments of the present disclosure.

[0008] Figure 6 shows a similar diagram to Figure 5 but with a different flow rate, resulting in a slightly different shape of the transitional region B. SUMMARY

[0009] Embodiments of the present disclosure are directed to a fluid mixing apparatus including a mixing chamber, a rotating blade within the mixing chamber configured to rotate about a shaft within the mixing chamber to mix fluids in the mixing chamber. The mixing chamber has an inlet and the shaft is within the inlet. The fluid mixing apparatus also includes a chute coupled to the inlet and being configured to direct a dry, powdered material into the inlet, and a material inducer comprising a rotatable sleeve and a plurality of vanes protruding radially from the sleeve, the material inducer configured to rotate. Rotation of the material inducer causes the vanes to agitate the dry, powdered material in the chute. The fluid mixing apparatus also includes a fluid inlet comprising an annular space surrounding the chute. The annular space and the chute are within the inlet of the mixing chamber. The fluid inlet is configured to discharge a cylindrical curtain of fluid into the mixing chamber. The rotation of the material inducer causes the dry, powdered material to move radially outwardly to contact an interior portion of the curtain of fluid. In further embodiments the annular space comprises a fluid inlet oriented circumferentially with respect to the annular space, such that incoming fluid pressure is directed to move around the annular space. In some embodiments fluid inlet has a first width and a continuously decreasing width around the annular space, such that fluid discharged from the annular space forms the curtain of fluid.

[0010] Further embodiments of the present disclosure are directed to a chute for a cement mixer including a cylindrical conduit configured to be coupled to an inlet of a cement mixer, and a material inducer positioned in the cylindrical conduit and configured to rotate within the cylindrical conduit. The material inducer has a plurality of vanes extending radially outwardly. Rotation of the material inducer within the cylindrical conduit pulverizes the dry cement and forces the dry cement outwardly against an interior surface of the cylindrical conduit and advances the dry cement toward the cement mixer. The chute also includes a fluid channel configured to receive fluid for mixing with the dry cement, the fluid channel being positioned circumferentially around an exterior portion of the cylindrical conduit, the fluid channel being configured to deliver a generally uniform curtain of fluid downward and into the cement mixer. [0011] Still other embodiments of the present disclosure are directed to a method of mixing a fluid with a dry, powdered material. The method includes discharging the fluid into a mixing chamber in a fluid annulus having substantially uniform thickness around the fluid annulus, introducing the dry material into the mixing chamber from within the fluid annulus, and causing the dry material to move radially outwardly onto an interior surface of the fluid annulus. The method also includes mixing the fluid and the dry material together within the mixing chamber, and agitating the dry material with a rotating inducer configured to reduce clumping of the dry material before reaching the fluid annulus.

DETAILED DESCRIPTION

[0012] Below is a detailed description according to various embodiments of the present disclosure. Figure 1 shows a cement mixing apparatus 100 including a mixing chamber 102, a cement inducer 104, a fluid channel 106, and a chute 108. The mixing chamber 102 includes mixing blades 110 which are rotatably mounted within the apparatus 100 such that the blades 110 spin about a central axis 112 of the apparatus 100 when mixing is underway. The mixing chamber 102 can be a vortex blender. The apparatus 100 can include a shaft 114 which is fixedly connected to the blades 110 via a bolt 117 such that rotation of the shaft 114 drives the rotation of the blades 110. In other embodiments, the shaft 114 is free to rotate with respect to the blades 110. The blades 110 can be rotated independently from the shaft 114. In still other embodiments, the blades 110 are configured to move within the mixing chamber 102 independently from the rotation about the central axis 112.

[0013] The inducer 104 is a generally cylindrical structure arranged vertically above the cement mixing chamber 102. The inducer 104 can be mounted to the shaft 114 such that the inducer 104 rotates with rotation of the shaft 114. The inducer 104 includes vanes 116 configured to impart a downward force upon fluid material as the inducer 104 rotates. The shape and orientation of the vanes 116 can vary greatly. The rotational direction can be adjusted as needed, in which case the angle of the vanes 116 can change. In the embodiment shown the vanes 116 are helically extended; in other embodiments the vanes can be discrete flat, angled sections. Other shapes and sizes are contemplated as well without departing from the present disclosure. The vanes 116 are positioned within the chute 108 with the vanes in some embodiments reaching nearly to an interior surface 118 of the chute 108. In other

embodiments the vanes 116 extend partially toward the interior surface 118, allowing some space between the vanes 116 and the interior surface 118.

[0014] Material is introduced to the inducer 104 such that the material contacts the exterior surfaces of the inducer 104, and that rotation of the vanes 116 causes the vanes 116 to impart a downward force to the material, thereby urging the material into the cement mixing chamber 102. The movement of the vanes 116 also mixes the material to promote a uniform blending and to prevent clumps. In other embodiments, the inducer 104 can be positioned below, or to the side of, the mixing chamber 102.

[0015] The apparatus 100 also includes a chute 108 configured to receive the material in a suitably angled orientation with respect to the inducer 104. The chute 116 can surround the inducer 104 around a complete circumference, or partially. In some embodiments, the material introduced through the chute 108 can be cement. In other embodiments a different material can be used. The material can be powder, liquid, granular, or another suitable fluid material which will flow under the force of gravity or under pressurized introduction. As the inducer 104 rotates, the vanes 116 spin and draw the material downward past the inducer 104 and into the mixing chamber 102. The rotation of the inducer 104 can be relatively high, such that the material moves radially outwardly and away from the inducer 104. The material can be urged toward and against an inner surface 118 of the chute 108 and away from an exterior surface 120 of the inducer 104. The void left at the interior radial location can be used to allow dust and air to exit the material, improving the quality of the eventual slurry.

[0016] The apparatus 100 also includes a fluid channel 106 configured to introduce a secondary fluid, such as water, to the mixing chamber 102. The secondary fluid can be water or any other suitable fluid useful for a given application. For purposes of brevity and without loss of generality, the secondary fluid is referred to as water. The fluid channel 106 is configured to receive the water along the path indicated at 122. The path 122 circumnavigates the inducer 104 and has an opening at the bottom through which the water leaves the fluid channel 106. The lower portion of the fluid channel 123 are substantially vertically arranged such that the water leaves in a cylindrical curtain of water which mixes with the material from the inducer 104 to form a quality mix.

[0017] The rotation of the vanes 116 causes the material to move downwardly and radially outwardly toward the curtain of water to promote even mixing with the water. Radially outwardly of the water curtain is the remainder of the mixing chamber 102 within which is the slurry formed by a combination of the water and the material from the inducer 104.

[0018] In some embodiments the fluid channel 106 is volute. In this disclosure, volute means that the radial dimension of the path from around the circumference of the fluid channel 106 becomes smaller as a function of circumferential travel. The dimension 124 is greater than the dimension 126. The water travels around the fluid channel 106 and first moves through the portion with the dimension 124 and later reaches the portion with the dimension 126. Figure 2 also illustrates the volute characteristic. The volute dimensions can be determined from the rate at which the water flows through the fluid channel 106. The diminishing size of the fluid channel 106 accommodates the portion of water which leaves the fluid channel 106 as it circles the inducer 104. In some embodiments, the curtain of water leaving the fluid channel 106 is substantially uniform in thickness and fluid rate at each point around the circumference.

[0019] It is to be understood that a moving flow of fluid may not be completely uniform, and that the nature of flowing fluid is dynamic and difficult to measure and to maintain perfectly uniform. Herein the term "substantially uniform" means that within a reasonable

approximation the thickness of the stream, as measured from time to time and at nearly all or all radial positions around the stream, is reasonably similar. It is also to be understood that the fluid curtain, or fluid annulus, may or may not comprise a complete circle, and that the annulus need not be a circle and that an ellipse or other natural shape is contemplated by the present disclosure.

[0020] Figure 2 is an isometric cut-away view of the fluid channel 106 according to

embodiments of the present disclosure. The inducer 104 and shaft 114 can be seen partially cut away in the center of the assembly. The fluid channel 106 creates a path 122 for the water to follow. The water enters the fluid channel 106 and circles the fluid channel 106. For purposes of explanation, three points 130, 132, and 134 along the path are described here. These points represent a chronological order in which the water travels. The width of the fluid channel 106 at each succeeding point is smaller than the previous point. For example, point 130 is wider than point 132, which in turn is wider than point 134. In some embodiments the reduction in width is linear. In other embodiments the reduction is exponential, geometric, logarithmic, monotonic, or some combination thereof. It is to be understood that the reduction in the width dimension refers to the general trend along the circumference, and that small disruptions, such as a notch or a groove would create a small local increase in width, which technically would interrupt the general trend of reduction. But these changes do not affect the resulting uniform curtain of water leaving the bottom of the fluid channel 106.

[0021] In other embodiments the path 122 can comprise a tank that holds a certain volume of water above a circular opening in the path 122. The tank and lower opening can discharge a desired curtain of water downward into the mixing chamber. The amount of water introduced to the tank can be adjusted so that there is a steady level of water above the mixing chamber with a certain discharge rate coming out of the bottom of the tank. The input and discharge rates can be substantially the same when the apparatus is up and running for any length of time after a starting period during which the tank is filled. In some embodiments the lower opening can be selectively closable to allow the tank to be filled before starting the mixing process, after which the lower opening can be opened to discharge the water below as more water is introduced into the tank to replenish the water in the tank.

[0022] The resulting flow caused by the configuration of components described above with respect to Figures 1 and 2 is a more uniform combination of primary and secondary fluids. In some embodiments the primary fluid is the cement which is introduced dry through the chute 108 and the secondary fluid is the water introduced through the fluid channel 106. It is to be understood that other fluids can be used for the primary and secondary fluids and the disclosure is not limited to cement and water. The cement is introduced dry to the chute 108. Cement in its dry form is approximately half voids, or air, and half solid particulate by volume. The inducer 104 impa rts a downward force causing the cement (or other fluid) to rid itself of the air in the mix, which then is permitted to leave through a central column created near the inducer 104. In other embodiments, the inducer 104 can have a passage separated out to allow the air to escape. The cylindrical curtain of water formed by the volute fluid channel 106 enables a uniformity of mixing between the water and cement. The mixed material exits the mixer in a spiral manner in the direction of the vortex. The momentum of the material helps centrifuge or propel itself to join the vortex wall of fluid, leading to a larger "spread-out" surface contact area between the dry material and fluid wall of the vortex, a self- propelling/centrifuging action that prevents clogging up the opening for dry material introduction, which in turn promotes a higher mass flow rate.

[0023] The design is similar to a C-Pum p volute to encourage more even distribution of material at the outlet. This is because the material has momentum to want to travel towards the end of the spiral.

[0024] The assembly can feature steep angled walls to ensure gravity and material potential energy and momentum is fully taken advantage of. The highlighted area in red above or the roof may or may not be needed, as it will be one of the factors that determine the limit of material flow, but in some embodiments it can help streamline the material and focus the air rejection paths towa rds the center. This design promotes first in first out flow (minimal dead space) which will be useful to self-clean and prevent excessive build up.

[0025] Air nozzles can also be observed that can help with breaking buildup or encouraging flow. Any other means (e.g. mechanical vibrations) can also be used. Where applicable, fluids may be injected for more thorough cleaning.

[0026] Em bodiments of the present disclosure, in addition to the above-mentioned requirements, also satisfy the following constraints:

^■ Mixer Flow Rate 16 bpm (at the discharge)

^■ Water injector operating flow range: 0.5 - 8 bpm

[0027] Figure 3 is an isometric view of a mixer assembly 200 having a plura lity of vanes according to em bodiments of the present disclosure. The assembly 200 can have some components which are generally analogous to features described elsewhere in this disclosure, including a mixing chamber 102. The assembly 200 includes a sidestream collector 202 configured to receive cement from a port 204 above the sidestream collector 202 and water from a port 206 at a side of the assembly 200. The assembly also includes vanes 208 which are stationary relative to the assembly 200, but are positioned at an angle relative to the downward flow of the cement such that a rotational movement component is introduced to the cement as it passes into the mixing chamber. This promotes even mixing and a more uniform resultant slurry. As with previous embodiments, the fluids to be mixed are not limited to cement and water; rather, any combination of two or more fluids can be used with embodiments of the present disclosure. The vanes 208 may be vertical, and there can be vanes of varying orientation. Some vanes may be vertical and some may be angled. In some embodiments the vanes 208 are equally spaced apart, while in other embodiments the vanes 208 can be staggered to have vanes closer together in certain regions and more spaced apart vanes in others. The incoming fluid from the sidestream collector 202 may have a momentum in a circumferential direction. The vanes 208 can operate to direct the momentum in such a way to promote a uniform fluid curtain from the collector 202 into the mixing chamber 102. The embodiments shown in Figure 3 may be used with a tank configuration in which there is a tank (not shown) of water above the mixing chamber 102 that is to receive fluid and store the fluid at least temporarily before allowing the fluid to enter the mixing chamber 102. The vanes 208 can be sized and oriented to promote a more complete mixing of the fluid and the material in the chamber 102.

[0028] Figure 4 shows an embodiment according to the present disclosure in which the vanes are eliminated and the shape of the volute liquid port 302 are used to impart the desired movement to the material. The shape and size of the liquid port 302 can vary according to the needs of a given application. In the case of the assembly 200 of Figure 3 including vanes and that of Figure 4 without vanes, the water is discharged downwardly in a curtain that promotes even mixing of the water with the material. In some embodiments the apparatus includes a collector with an inlet pipe having an interior diameter of approximately 2.5 inches, sixteen guide vanes having an angle of 70° from vertical.

[0029] Figure 5 is a fluid diagram achieved using computational fluid dynamics. The fluid within the diagram shows fluid volume fraction. There are effectively four regions of different fluid volumes: a first region A which is zero or nearly zero fluid volume fraction; a second region B which is a transitional region between regions A and C; a third region C in which the fluid volume is 100% or nearly 100%; and a fourth region D in which fluid is introduced into the mixing chamber. Material such as dry cement is introduced into the mixing chamber as region A, while the fluid comes in through the port 310. The cement (or other material) is dry when it enters, thus the fluid volume fraction is zero or very nearly zero. Water is introduced via a fluid port at 310. The water can be seen as a vertical curtain of water falling downwardly into the mixing chamber. While the curtain need not be vertical, gravity acting on the water generally causes a vertical shape. The water and the material are mixed together at the curtain, and the rotation of the mixing chamber or the blades therein cause the mixture to move radially outwardly through centripetal force. The mixture in region C is fully mixed. The shape of the curtain and the way in which the fluid and material are introduced results in a more uniform mixing and prevents clumping of the material.

[0030] Some embodiments of the present disclosure feature a combination of the volute cross sectional area and axial passage result in the liquid swirl that is comparable to the swirl in the mixer for the operating condition. The volute sidestream flow smoothly merges with the mixer slurry at all flow rates. At 0.5 bpm free surface interface is formed at the sidestream passage due to the gravitational separation. In certain embodiments of the present disclosure include a volute cross sectional area including vanes. In other embodiments, there are no vanes and the circumferential fluid motion is created by the sidestream structure as shown and described with respect to figures 1, 2, and 4.

[0031] Figure 6 shows a similar diagram to Figure 5 but with a different flow rate, resulting in a slightly different shape of the transitional region B. Embodiments of the present disclosure include flow rates of between 0.1 barrels per minute (bpm) and 8 bpm. In some embodiments the rate can be as high as 30 bpm. Other, higher rates may also be possible. In some embodiments, a differential pressure exists in the sidestreams (water inlet) and the mixer itself. The mixer/pump pressure rise is unaffected by the added flow from the liquid.

[0032] Embodiments of the present disclosure are directed to systems and methods for improving rig-up and rig-down time. For many cement operations, there is a need to rig up every day for every job. Existing methods include having a cement crew with at least four people. Embodiments of the present disclosure are directed to a mechanical device configured to drag the connections into place, rather than having a crew join a series of hoses and iron to make connections. In some embodiments, the system includes the use of an exo-skeleton to assist with rigging up. The device would lend strength to speed up the process of rigging up.

[0033] For many rigging and cementing operations, it is desired to pump at rates higher than 8 bpm, so we may need two 4-inch suction hoses instead of only one as is typical of current operations. Some prospective APEX equipment sets envisions preparation of mix fluid on one trailer and the high-pressure triplex pumps on a different trailer, with a hose connecting these two units. A four-inch hose can be used in some embodiments.

[0034] There are high-pressure connections between the triplex pumps and the cement head on the rig floor. A possible issue created is that the cement head is too heavy to carry, often 1000 - 1500 lbs. Future developments may increase the weight as features are added. Often this is carried on the back of an ABT and moved by the location's forklift to a position near the V-door, where the rig's winch can reach it to lift it up to the rig floor. It would help if we had a means of moving this horizontally without relying on cooperation from the rig. Their forklift operator may be unavailable to perform this step.

[0035] In some embodiments, a mechanical dolly can be utilized to carry hoses from place to place to rig up and down. The dolly may be a motorized, remotely-operated machine with wheels, and a bed/cargo area and appropriate clamps to grip the hoses. The dolly can have sufficient power to drag heavy hoses from place to place in place of using manual labor to do so. [0036] Another potential issue on the high-pressure side is the treating iron deployed between the triplex pumps and the cement head. This today is typically 2-inch, but the flow through that is limited to 8 bpm. There is a desire to cement at a higher rate, but doing so would require a larger hose, which would be even heavier and more onerous to deploy.

[0037] Summarizing, we have four different deployment challenges for cementing: First, a hose from our mixing unit to the rig's water and mud tanks. (This could be one hose or two different hoses.) Second, a hose from an APEX mix fluid trailer to the pumper trailer, if these are separate units. Third, moving of the cement head from its transport position to the V-door. And fourth, moving the end of the high-pressure hose from its storage reel to the V-door.

[0038] A common solution for these four challenges would be beneficial, but it is possible to have different solutions. There are several possible approaches to solving these problems. In one embodiment, a simple winch and pulley can be used. A pulley could be attached near the point of the rig to which we wish to connect, and then the cable can be spooled off the winch to go around the pulley and back to the unit where it is connected to the hose to be deployed. Hoses may be stored on a reel to make them easy to deploy. Spooling up the cable will draw the end of the hose to the desired point.

[0039] A safeguard against pinch points could be added at the pulley and winch to keep fingers and hands out. In some embodiments synthetic ropes could make this safer. In some embodiments a synthetic crane line can be used. This has low stretch and, unlike steel cable, never has dangerous broken wires sticking out.

[0040] The figures of the present disclosure are used to illustrate a particular situation and are not disclosed in a limiting manner in any way. To calculate how much pull, look at the weight of the hose to be pulled. Low pressure hose weighs about 2.6 lb/ft. If the hose is full of 1.5 SG fluid, that adds 8.14 lb/ft. The maximum horizontal drag will be about 100 ft. For the coefficient of friction, consider that tires on dry pavement have friction coefficient of about 1.0, and on gravel half that. Using 1.0, to drag 100 ft of 4-nch hose full of 1.5 SG fluid requires a pull of 1074 pounds. If the hose is empty, the drag falls to only 260 pounds. [0041] Likely we will have hoses on reels, in which case a take-up motor can provide the force to retract the hose. The Mechanically Assisted Deployment (M.A.D.) device is needed more to stretch the hoses out, in which case the hoses are sure to be empty.

[0042] Another case for high drag force is the high-pressure hose. Our most popular cementing hose is PARKER™ P5675 which has 2-inch ID and weighs 5.29 lb/ft. Full of 1.5 SG fluid, this requires 730 pounds of tractive effort to drag 100 ft.

[0043] In most applications the hoses are deployed away from the trailer on which the winch is mounted, snatch blocks can be used. The snatch blocks are attached past the point to which we want the hose to go, and then drag the hose out. A block can be put over the rope easily.

[0044] In further embodiments a winch can be used attached to the cementer and to perhaps one other anchor point. A motor can be used to pull a cable or rope attached to the hose to move it into position. Yet another approach is to use a motorized dolly or cart with enough power to move the hose into position. In some embodiments the dolly or cart can be an unmanned, remote controlled vehicle with sufficient strength and weight to move the hose into position. There are various examples of such a device on the market today.

[0045] Features and aspects of the present disclosure have been given in some cases with dimensions and parameters having a numerical value. Such parameters are not to be construed to be limiting and are given as examples of embodiments of the disclosure without limitation.

Claims

1. A fluid mixing apparatus, comprising:

a mixing chamber;

a rotating blade within the mixing chamber configured to rotate about a shaft within the mixing chamber to mix fluids in the mixing chamber, the mixing chamber having an inlet, the shaft being positioned within the inlet;

a chute coupled to the inlet and being configured to direct a dry, powdered material into the inlet;

a material inducer comprising a rotatable sleeve and a plurality of vanes protruding radially from the sleeve, the material inducer configured to rotate, wherein rotation of the material inducer causes the vanes to agitate the dry, powdered material in the chute; and

a fluid inlet comprising an annular space surrounding the chute, wherein the annular space and the chute are within the inlet of the mixing chamber, wherein the fluid inlet is configured to discharge a cylindrical curtain of fluid into the mixing chamber, wherein the rotation of the material inducer causes the dry, powdered material to move radially outwardly to contact an interior portion of the curtain of fluid.

2. The fluid mixing apparatus of claim 1 wherein the vanes are helical.

3. The fluid mixing apparatus of claim 1 wherein the chute comprises a generally vertical portion in which the material inducer is positioned and an angled portion configured to receive the dry, powdered material.

4. The fluid mixing apparatus of claim 1 wherein the annular space is volute.

5. The fluid mixing apparatus of claim 1 wherein the annular space comprises a fluid inlet oriented circumferentially with respect to the annular space, such that incoming fluid pressure is directed to move around the annular space.

6. The fluid mixing apparatus of claim 5 wherein the fluid inlet has a first width and a continuously decreasing width around the annular space, such that fluid discharged from the annular space forms the curtain of fluid.

7. The fluid mixing apparatus of claim 6 wherein the curtain of fluid has a generally uniform thickness around a circumference of the curtain of fluid.

8. The fluid mixing apparatus of claim 1 wherein the vanes rotate sufficiently fast to cause the dry, powdered material to move radially outwardly from the sleeve, leaving a void adjacent the sleeve.

9. The fluid mixing apparatus of claim 1 wherein the dry, powdered material is cement and wherein the fluid is water.

10. The fluid mixing apparatus of claim 1 wherein the rotating blade and material inducer are coupled to the shaft.

11. The fluid mixing apparatus of claim 1 wherein the annular space comprises a tank configured to hold a certain quantity of fluid above the annular space.

12. The fluid mixing apparatus of claim 1, further comprising a plurality of directional vanes fixed to the mixing apparatus that are configured to receive the fluid from the fluid inlet and to direct the fluid into the mixing chamber.

13. A chute for a cement mixer, the chute comprising:

a cylindrical conduit configured to be coupled to an inlet of a cement mixer;

a material inducer positioned in the cylindrical conduit and configured to rotate within the cylindrical conduit, the material inducer having a plurality of vanes extending radially outwardly, wherein rotation of the material inducer within the cylindrical conduit pulverizes the dry cement and forces the dry cement outwardly against an interior surface of the cylindrical conduit and advances the dry cement toward the cement mixer; and a fluid channel configured to receive fluid for mixing with the dry cement, the fluid channel being positioned circumferentially around an exterior portion of the cylindrical conduit, the fluid channel being configured to deliver a generally uniform curtain of fluid downward and into the cement mixer.

14. The chute of claim 13 wherein the vanes extend partially but not completely to interior walls of the cylindrical conduit.

15. The chute of claim 13 wherein the vanes are helical.

16. The chute of claim 13 wherein the fluid channel is volute.

17. The chute of claim 13, further comprising a vacuum apparatus coupled to the cylindrical conduit and configured to extract air-borne particles from the cylindrical conduit.

18. A method of mixing a fluid with a dry, powdered material, the method comprising: discharging the fluid into a mixing chamber in a fluid annulus having substantially uniform

thickness around the fluid annulus;

introducing the dry material into the mixing chamber from within the fluid annulus;

causing the dry material to move radially outwardly onto an interior surface of the fluid

annulus;

mixing the fluid and the dry material together within the mixing chamber; and

agitating the dry material with a rotating inducer configured to reduce clumping of the dry material before reaching the fluid annulus.

19. The method of claim 18, further comprising redirecting the fluid into the mixing chamber with a plurality of vanes fixedly attached to the mixing chamber in the path of the fluid.

20. The method of claim 18, wherein the rotating inducer rotates with sufficient speed to cause the dry material to move radially outwardly from the inducer within a chute, the chute being configured to direct the dry material into the mixing chamber.

21. The method of claim 18 wherein discharging the fluid into the mixing chamber comprises directing a flow of the fluid in a circumferential direction into a volute annulus havi a port configured to discharge the fluid into the mixing chamber, wherein the port and the volute annulus are shaped to achieve a substantially uniform thickness of the fluid annulus.