Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28C—PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28C5/00—Apparatus or methods for producing mixtures of cement with other substances, e.g. slurries, mortars, porous or fibrous compositions
  • B28C5/08—Apparatus or methods for producing mixtures of cement with other substances, e.g. slurries, mortars, porous or fibrous compositions using driven mechanical means affecting the mixing
  • B28C5/18—Mixing in containers to which motion is imparted to effect the mixing
  • B28C5/20—Mixing in containers to which motion is imparted to effect the mixing rotating about a horizontal or substantially horizontal axis during mixing, e.g. without independent stirrers
  • B28C5/2045—Parts or components
  • B28C5/2054—Drums, e.g. provided with non-rotary mixing blades
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F29/00—Mixers with rotating receptacles
  • B01F29/25—Mixers with rotating receptacles with material flowing continuously through the receptacles from inlet to discharge
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F29/00—Mixers with rotating receptacles
  • B01F29/60—Mixers with rotating receptacles rotating about a horizontal or inclined axis, e.g. drum mixers
  • B01F29/63—Mixers with rotating receptacles rotating about a horizontal or inclined axis, e.g. drum mixers with fixed bars, i.e. stationary, or fixed on the receptacle

Definitions

• the present invention relates to a device in connection with apparatuses as concrete mixers , which exhibit a rotatable drum with lying axis of rotation and with one end, which is provided for the input of the material that shall be mixed, and one end which is provided for the discharge of the mixed material, and with a shell, which supports for one thing a number of mixing wings, which exhibit a screwlike arrangement, so that during the rotation of the drum in one direction, the mixing direction, they tend to convey the material in axial direction towards the input end and during the rotation in the opposite direction, the discharge direction , they will feed the material in axial direction towards the discharge end, and for another thing additional mixing wings , of which each one is attached in such a position relative to one of the first mixing wings that the additional wing is below the belonging first wing, when this wing as a consequence of the rotation of the drum in the mixing direction is in an angular position, which means that the material carried along by the wing slides off the same, so that this material then hits the belonging outer wing, which exhibits
• the invention especially relates to free-fall mixers with a lying mixing drum and discharge wings .
• a mixer of the type considered here exhibits a horizontal mixing drum with two series of wings , viz . mixing wings and discharging wings .
• the drum is charged at one end, and the material then meets the mixing wings , which move the material in upwards direction and again lets it fall down, whereby the ingredients of the mass are mixed together.
• the wings are adjusted in such a way that the material is kept back at the input end of the drum.
• the mixing wings then feed the material in direction away from the input end towards the other end of the drum, when the material is discharged by means of the helicoidal setting of the discharge wings .
• the horizontal position of the drum is maintained during the charging, mixing arid emptying operations .
• the invention has been made with the intention to solve said problems in connection with the mixture of concrete , but the invention is also applicable to mixing apparatuses in other fields , where a thorough mixture of several ingredients in widely varying proportions is required.
• the object of the present invention is obtained by a device which is characterized by the additonal wings being designed with a preferably chute-shaped side, which is directed towards the frontrunning first wing and permits that the material falling down on the wing is conveyed in its longitudinal direction , while the wing is inclined, and an opposite side with surfaces inclining outwards their edges and arranged to permit the material falling down on this side to sidewise leave the wing in a movement that is transversal to the wing, so that the transportation by means of the additional wing takes place in axial direction in connection with a rotation in substantially the mixing direction only , and the movement of the material in the discharge direction during a corresponding rotation by action of the first wings which preferably are supplemented by action of special wings at the discharge end, is substantially unaffected by the additional wings .
• Fig. 1 is a side elevational view of a mixer according to the invention
• Fig. 2 a partial cross-sectional view and Fig. 3 in a cross-sectional view along the line III-III in Fig. 2 illustrate a fastening arrangement of a mixing wing
• Fig. 4 is a longitudinal cross-sectional view through a mixing drum
• Fig. 5 is a perspective view of the drum in partly cut-up condition .
• the concrete mixer according to the example of embodiment illustrated substantially corresponds to a conventional concrete mixer of the free-fall type.
• a mixer exhibits a mixing drum 1 , which at its ends is supported by rollers 4 with driving rings 3.
• the rollers 4, of which only two are illustrated in Fig . 1 are four in number and are journalled in a frame 5 with bearings 6. Both the illustrated rollers are arranged to be driven by motors 7 via power transmissions 8. Rollers 9 are provided at each end for axial control.
• the mixing drum exhibits a shell with a cylindrical portion 10, a first conical portion 11, and a second conical portion 12.
• first conical portion 11 there is an input opening 13
• discharge opening 14 in the other conical portion 12 there is discharge opening 14 (see Figs . 4 and 5) .
• a charging device 15 is provided at the input end 11 , 13 and comprises a filling hopper 16 for aggregate, a filling hopper 17 for cement, a filling pipe 18 for water, which is conducted from a water tank 19, and one or several receptacles 20 for such additives , which shall be present in small relative quantities .
• the receptacle or receptacles 20 debouch in the pipe 18 , which in its turn debouches in a feeding drum 21, to which also the feeding hoppers 16, 17 are connected.
• the feeding drum 21 is connected with the input opening
• the general design of the mixing machine has now been described, and the following description therefore substantially refers to the wingsystem housed in the mixing drum 1, the main features of which are illustrated in Figs . 4 and 5.
• the wing system comprises three series of wings , viz . outer mixing wings 22, inner mixing wings 23 , and discharge wings 24.
• the mixing wings 22 are placed on the inside of the cylindrical portion 10 and distributed on two holder devices located one after the other in axial direction.
• the discharge wings 24 are placed on the inside of the other conical portion 12.
• the outer mixing wings 22 and the discharge wings 24 ex hibit an oblique mounting and can be considered to form parts of a thread with several entries, the thread direction being common for the wings 22 and 24.
• All of the wings 22 and 24 comprise sheet metal blades with an inner edge, which with respect to inner surfaces of the portions 10 and 12 respectively and the oblique mounting of the wings exhibits such a curved shape that said outer edge obtains a good contact with the wall of the drum 1.
• the free edges of the wings are substantially adapted to the conditions of manufacture and according to the drawings exhibit straight lines .
• the design of the discharge wings is not a characteristic feature of the invention, but corresponds to what is used in the prior art.
• the outer mixing wings as to their main features correspond to what has hitherto been common features of the design of free-fall mixers .
• the mounting of the wings 22 and 24 is in detail evident from Figs . 2 and 3.
• the wing 22 exhibits a rectangular opening 25 departing from the edge 26 of the wing facing the shell portion 10.
• a sleeve 27 with a through hole is welded into this opening .
• a screw 28 with a nut 29 which is located in a free portion of the opening 25, located inside the inner end of the sleeve 27, extends through a corresponding hole in the wall of the shell 10.
• the wings are attached by means of a number of screws 28 being led through the wall of the shell and into the sleeves 27 of the wing and being tightened by means of a corresponding number of the nuts 29.
• the discharge wings 24 are mounted in a corresponding manner.
• the drum in mixers of this type is often lined with a wear resistant rubber, which then covers the means of attachment.
• the inner mixing wings 23 extend between the corners of the outer mixing wings 22.
• the inner mixing wings 23 exhibit a V-shaped profile .
• the location of the inner mixing wings can be described in the following manner:
• the outer mixing wings 22 can be considered to have a rear edge 30 and a forward edge 31 , if one takes into consideration the direction of feed through the drum 1 , viz . from the input end 11 , 13 towards the discharge end 12 , 14.
• the forward edge 31 is at the same time because of the oblique mounting of the wings the front-running edge , when the drum performs its rotation in the mixing direction indicated by an arrow 32 in Fig. 5.
• each holder device exhibits three outer mixing wings 22, the angular distance between them consequently being 120° .
• the inner mixing wings 23 extend between the rear succeeding edge 30 of one of the outer mixing wings 22 and the forward front-running edge 31 of the outer mixing wing 22, which is the wing that follows in the direction of rotation , when the mixing is going on (see arrow 32) .
• This thus , means that each inner mixing wing 23 extends from the rear succeeding corner of an outer mixing wing and forwards in the direction of feed and backwards in the direction of rotation to the front corner of next outer mixing wing 22.
• the concave sides of the inner mixing wings 23 are directed towards the front-running wing and the convex side towards a succeeding wing of the outer mixing wings, which it connects .
• each holder device of the outer mixing wings 22 the wings in between them are connected by means of a separate holder device of three inner mixing wings 23, whereby also the inner mixing wings form two holder device sets .
• the connection between the outer and the inner mixing wings according to the example of embodiment takes place by means of a fastening means 33 comprising two plates, which in between them are distorted, and which give the correct angle between the two wings , said plates being attached to the respective wings by means of rivets or screws .
• the inner mixing wings thus , do not have any direct attachment to the mixing drum 1.
• said machine can comprise additional features , such as the inner lining of the mixing drum with wear resistant rubber, a dosing equipment at the input, some form of collecting means at the output etc .
• additional features such as the inner lining of the mixing drum with wear resistant rubber, a dosing equipment at the input, some form of collecting means at the output etc .
• such details and such equipment are of earlier known kinds and have no direct significance for the invention, because of which they are left out of the description .
• the different ingredients after dosage are made to fall down from the input means 15 into the drum 1.
• this means that aggregate is supplied through the hopper 16, cement through the hopper 17, water and one or several ingredients in small quantities from the tank or receptacles 20 through the pipe 18.
• the ingredients are in troduced into the mixing drum 1 through the input opening 13 and thus land up close to the input end at the shell portion 11.
• the drum is rotating in the direction of the arrow 32, which is the case during a mixing operation, the ingredients will be mixed together with each other by means of the cooperation between the mixing wings 22 and 23.
• the mixing mass remains within the area of the shell portion 10 , and the mass , which possibly finds its way towards the shell portion 12, will be fed back by the discharge wings 24, which operate as a screw in direction towards the shell portion 10.
• the rotation of the drum 1 is reversed.
• the outer mixing wings 22 will then feed the mass in forwards direction to the shell portion 12, where it is caught by the discharge wings 24, which during this direction of rotation in a screwlike manner feed the mass in forwards direction to the output opening 14 and out through this opening.
• the drum is thereby emptied of the ready prepared mixture for its subsequent transportation to the place, where it shall be used.
• the drum is now ready for a new mixing cycle .
• the mixing wings during the mixing operation work in the following manner: It can be assumed that the ingredients , when filled through the opening 13, will land up in the section 10 immediately inside of the section 11, and thus , during the rotation of the drum 1 be carried along the outer mixing wings 22 in a direction which as seen in Figs . 4, 5 points upwards/away (see the arrow 32) .
• the inner wing 23 exhibits a forwards inclination , and thus , the material will slide forwards and is then thrown outside the end of the wing (see the arrow 35) and lands up in front of one of the outer mixing wings 22 of the holding device.
• this wing in its turn is lifted during the continued rotation, the material will slide down from the wing into the inner mixing wing 23 (see the arrow 36) , which is connected with its rear corner.
• the mixing mass thus will carry out a cyclic course, where the axial feeding movement of the mixing mass in an outer ring represented by the outer mixing wings 22 is in direction towards the input end 11 , 13, and where the axial direction of feed in an inner ringshaped volume represented by the inner mixing wings 23 is in opposite direction towards the output end 12, 14.
• the particles of the mass will continuously change position relative to each other in radial direction because of their rising and falling movements as well as in axial direction because of the sliding movement performed in both axial directions along the wings .
• the wings in question therefore have an inclination in direction towards the input end 11 , 13 , a fact which could result in that a certain portion of the material would be returned to the input end, so that the discharge would be incomplete or in any case would take an unnecessarily long time .
• this effect is avoided because of the angular profile of the wings .
• they serve the purpose of chutes , which convey the material hitting the wings in the intended mixing direction without any lateral spillage .
• the material hits the ridge side of the wings , for which the angles are determined in such a manner that the angle of lateral down-slide is greater than the one in the longitudinal direction , whereby the material is not axially transported but falls straight down and is consequently taken care of by the outer wings 22 in order to be fed towards the discharge opening .

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Structural Engineering (AREA)
• Preparation Of Clay, And Manufacture Of Mixtures Containing Clay Or Cement (AREA)
• Mixers Of The Rotary Stirring Type (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

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ID=20336962

Family Applications (1)

Country Status (3)

Cited By (4)

Families Citing this family (1)

Citations (4)

Family Cites Families (1)

• 1979
  • 1979-06-18 WO PCT/SE1979/000138 patent/WO1980002808A1/en unknown
  • 1979-06-18 DE DE19792953699 patent/DE2953699C2/de not_active Expired
  • 1979-06-18 GB GB8121626A patent/GB2074464B/en not_active Expired

Patent Citations (4)

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