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US 4,850,704 AGranted
Two stage blender
AssigneeLadish Co.
InventorsRobert D. Zimmerly, Robert J. Riemer
Life of this patent
Estimating the term…
Abstract
A two stage blender is capable of handling high viscosity liquid-powder mixtures. The mixture discharged from the first stage is directed to the second stage, from which it is discharged at a relatively high discharge pressure. The second stage further enhances the natural vacuum created within the first stage, so that powder is fed at a constant ratio for a wide variety of liquid flows. Selected internal parts of the blender are designed to permit cleaning the blender in place.
Claims12
A two stage blender for mixing liquid and powders into high viscosity end products comprising:
- a. means for introducing the liquid and powders into the blender;
- b. a first impeller mounted for rotation around a central axis and having a central recess of a first size for receiving the liquid and powder, the impeller imparting a radially outward acceleration to the powder and liquid to thereby mix them;
- c. a casing surrounding the first impeller and defining a uniform annular passage to receive the mixed liquid and powder, the casing being formed with a wall shaped to direct the mixture axially and radially inwardly toward the central axis;
- d. a pair of axially spaced baffle members concentric with the central axis for guiding the mixture from the casing annular passage inwardly toward the central axis and axially along the central axis;
- e. a second impeller mounted for rotation about the central axis in unison with the first impeller, the second impeller having a central recess of a second size less than the size of the recess of the first impeller for receiving the mixture from the baffle members and for imparting a second outward acceleration to the mixture;
- and
- f. discharge means in the casing uniformly surrounding the second impeller for receiving the mixture from the second impeller,
- so that the mixture is discharged from the blender at a high pressure notwithstanding high end product viscosity.
5 more elements
A blender for mixing solid particulates and liquid comprising:
- casing means having a side wall and a generally cylindrical interior disposed about an axis and nominally upper and lower end walls,
- first stage blender means including first baffle means spaced from said upper and lower end walls, respectively, inside of said casing means for defining first and second axially spaced apart generally circular coaxial spaces in conjunction with said upper and lower end walls, respectively,
- said first circular space having first central inlet means for said particulates and for said liquid,
- said first stage blender means including an impeller in said first space for being driven rotationally about an axis which is generally perpendicular to said baffle means, said impeller having generally radially extending imperforate vanes between which, in the region of the axis of the vanes, said particulates and liquid are drawn from said inlets such that when the mixture is centrifuged radially from said vanes at one volumetric rate a partial vacuum is developed at said inlet means for particulates,
- said vanes having ends terminating in spaced relation in respect to said casing wall so as to define a first passageway about the impeller for receiving the mixture, the vanes having a height in the axial direction which results in first clearance between said vanes and said upper end wall and baffle means defining said space so as to contribute to developing said vacuum,
- a second stage pumping means including an impeller in said second space coaxial with said first stage impeller and driven rotationally jointly therewith, said impeller having generally radially extending imperforate vanes terminating in spaced relation with respect to said casing wall so as to define a space around said impeller including outlet means for outflow of the mixture,
- said second stage including second baffle means which define said second circular space having a second central inlet in communication with said first passageway for said mixture to be drawn into the spaces between said vanes of the second stage impeller said second inlet having a smaller cross sectional area and said vanes of said second impeller having a second clearance with respect to the second baffle means less than said first clearance in said first stage and centrifugally pumped radially outwardly to said surrounding space at a volumetric rate sufficient for keeping the centrifuged volumetric output rate from the first impeller stage substantially constant and, hence, keeping said vacuum at said particulate inlet means substantially within a narrow range approximately independent of the viscosity of the mixture passing through said second stage, and wherein
- the total pumping effect of the vanes of the second stage impeller is greater than the total pumping effect of the blades of the first stage impeller to impart high pressure to said mixture and to provide for said second stage impeller maintaining the flow rate of the mixture to said output means sufficiently high to keep the mixture flowing away from said inlet means at a sufficiently high rate to induce a substantially constant vacuum at said inlet means regardless of the viscosity of said mixture.
5 more elements
Dependencies are inferred from the claim text.