DE3809661A1 - Apparatus for continuously mixing a building material - Google Patents

Abstract

Mixing pumps for building materials are known which are charged from a cylindrical supply container by means of an agitator and comprise essentially a mixing pipe which is inclined with respect to the horizontal plane and inside which a screw conveyor, a mixing tool and an eccentric screw pump are arranged in a coaxial arrangement. It is, however, disadvantageous in this arrangement that mutually separate drives are provided for the agitator tool in the supply container on the one hand and for the functional elements accommodated inside the mixing pipe on the other hand. An apparatus according to the invention is, in contrast, characterised by a funnel-shaped container (2) which is placed on the mixing pipe (1), so that the material contained in the container (2) passes into the mixing pipe (1) only under the influence of gravity. Only one motor (11) is required for the drive of the apparatus according to the invention, which motor is connected successively to a screw conveyor (5), an agitator tool (14) and an eccentric screw pump (10) via links (12, 13, 15). As a result of the said link connections, in contrast to the case of a rigid connection, it is achieved that the eccentric, elliptical circulating motion of the eccentric screw pump (10) is not obstructed so that the latter is driven under kinematically satisfactory conditions. <IMAGE>

Description

The invention relates to a device accordingly the preamble of claim 1.

Such devices are used for fully automatic mixing of dry material such as plaster, mortar, plaster cleaning, cement, etc., mainly as sack goods in Ver are used, but can also be delivered in silos and mixed with water and other additives have to.

From DE-PS 24 07 657 is a comparable device known, which next to a mixing tube with subsequent Eccentric screw pump on a second conveyor system points through which the dry material to be mixed in the mixing tube is conveyed. The disadvantage here is too first of all, that a total of two engines plus associated ones  electrical controls are needed, which makes the susceptibility to faults and - not insignificantly - the Increase generation costs. In this known device is the container for the dry material since Lich next to the mixing tube so that the dry matter goes up must be promoted. The mixing tube must therefore necessarily arranged more or less vertically be, so that the dry material only under the influence of gravity can fall into the mixing tube. However, this has the further disadvantage that the Mixing tool to achieve a satisfactory mix can only be operated at very high speeds, so that the risk of splashing mixed water into the Area of the mixing tube in which there is only dry material may be located. Especially with fast he hardening building materials can lead to deposits come which are suitable for continuous operation to affect, but at least too time-consuming Carry out cleaning work. Because of the high speeds of the mixing or stirring tool, which for example 400 Revolutions / per minute Eccentric screw pump driven at this speed on the one hand, their lifespan and on the other hand, the continuous suction of the stiff plastic mortar very difficult, which is among other things, shows that the mortar is often not is pumped continuously but intermittently. A white Another disadvantage of the known device is that there is blockage or kinking of the mortar hose or if the eccentric screw pump does not deliver enough to a backlog and subsequently to a climb of the water that comes into the water in this way upper area of the mixing tube and then further into the loading container for the dry material. This can  immediate complete emptying, cleaning and off drying of the container required, which at time consuming work breaks. Another after partly results from the fact that in this known before direction within the vertical mixing tube to drive the eccentric screw pump via a rigid mixing coil is connected to the respective motor. Because the screw of the progressing cavity pump is not rotates centrically but extremely eccentrically Mixing spiral forced an eccentric movement, so that the diameter of the mixing spiral is much smaller than the inside diameter of the mixing tube must be dimensioned. It can thus be unsafe on the outer edge of the mixing tube prevents hardening material from accumulating every end of work must be removed with great effort.

From FR-PS 15 72 335 a similar device be knows, in which from the lower end of a funnel-like Container the material to be mixed by means of a conveyor snail is first transported upwards and then one dose in succession in the downward direction screw, a mixing device and an eccentric screw pump runs through. The waves of the screw conveyor on the one hand and the dosing screw and the mixing tool of others on the one hand run parallel to each other, with an engine under Interposition of a gearbox to drive both Serves waves. The disadvantage here is the necessity an additional gear and the spatially ver relatively complicated material management.

Finally, from DE-OS 24 20 023 is a continuous Liche mixing pump known in which the to be mixed Material from a cylindrical container by means of a Agitator is discharged vertically and then in  a mixing tube arrives, which is inclined at an angle is arranged to the horizontal plane. Within the mix tubes are in an approximately coaxial arrangement Screw conveyor, a mixing tool and an eccentric worm pump. However, this is also a disadvantage known device that he two separate drives are required, on the one hand for the above Agitator inside the container and on the other hand for the system consisting of screw conveyor, mixing tool and eccentric worm pump.

It is the object of the invention to provide a device for to design the genre described at the outset in such a way that while avoiding the relevant state of the Technology inherent disadvantages in a simple manner trouble-free operation, especially without the formation of Deposits in the area of the mixing tube a perfect free mixing is achieved and a reliable and low-wear operation of the eccentric screw pump is possible. This task is solved with a genus appropriate device by the features of the labeling part of claim 1.

Because the container for the dry material to be mixed was used ter-shaped and directly on an almost horizontal Mixing tube is attached, the material can be placed under the Influence of gravity can be introduced into the mixing tube. The Mixing tube has the dimensions of the funnel-shaped Appropriate dimensions of the container and can be made from this Basically be sized accordingly, so that a accordingly large and long mix chamber can result, which at much lower Speeds, for example at 160 revolutions / min. up to 200 revolutions / min. can be operated. Here  is a homogeneous mixture and also a continuous one Lich pumping achieved, the latter due to the low Speeds. There is also a correspondingly increased Lifetime of the eccentric screw pump. It can too Light insulating mortar can be mixed properly. The gels The storage of the stirring tool mainly serves the purpose casual, because kinematically adapted drive of the Exzen worm pump, its eccentric, elliptical Movement through their articulated coupling with the agitator stuff is not hindered. Through this disability Free movement of the eccentric screw pump is not only ensures perfect pump performance, but the otherwise developed friction is also limited.

The comparatively large mixing tube volume in Ver binding with the mentioned, low speeds of mixing tool brings the further advantage of increased mixing time with yourself. It can with the Vorrich invention thus such materials are satisfactory are mixed, which has a comparatively longer mixing time make necessary.

Mixing pumps are of the type mentioned at the beginning Known technology associated type, the wet mixing chamber volume is approximately 1 liter, which results in a single pass rate of 20 liters / min thus a mixing time of only 1/20 min. In the device according to the invention however, their corresponding volume, for example Can be 5 liters, one results accordingly increased mixing time of 5/20 min.

The mixing tube is preferably according to claim 2 at least in the mixing area with thick walls with high wear armored solid, smooth plastic. The complete one  Armoring of the mixing tube with highly wear-resistant Plastic prevents the sticking and hardening of Building materials and the associated costly cleaning work.

The features of claims 3 and 4 will continue the formation of deposits in the marginal area of the mix tube counteracted, as this through the scraper beams can be largely removed, namely before it hardens. The Ab streak bar preferably extends over the essential part of the length of the mixing tube. Soon this scraper bar carries the Displace material in the peripheral area of the mixing tube effect also to the mixing. Through the Conveying spiral on the eccentric screw pump facing end of the mixing tube is arranged for even loading of the  Eccentric screw pumps with mixed material beige wear and thus to an even material conveyance. It is thus at the exit of the mixing tube through the ge called the helix a certain constraint on the material exercised towards the eccentric screw pump.

The split version of the conveyor spiral corresponds to the Features of claim 5 has been found to be of practical advantage proven, especially with regard to an equal moderate material discharge.

The features of claim 6 serve in addition to the Ver prevention of deposits in the peripheral area as well conveying the blended material towards the entrance of the eccentric screw pump.

The features of claims 7 and 8 result in a Mixing tool, which is arranged by means of a scraper on the outside beams and inward-pointing stirring arms characterized is. Wear both the agitator arms and the scraper bars contribute to the mixing effect, the latter in particular forehead can communicate with each other.

The features of claims 9 and 10 have been practical proven beneficial with regard to a good that Volume of the mixing tube uniformly detecting mixing effect the said webs also play a role. Latter exists in addition to a contribution to the mixing effect in particular in the function as a carrier for functional elements that the articulated connection of the mixing tool with the eccentric worm pump and the screw conveyor.

By the features of claim 11 is during the Mixing process the formation of voids or air favor in the mixed material, so that in this way a certain, the thermal insulation of the ge mixed material, e.g. porosity of a plaster  is achieved. The exact dimensions of the rectangle The cross-sectional profile of the mixing arms can be tables are chosen, it being in essentially only on the flow conditions the cross-sectional profile arrives during stirring, which favor the formation of the cavities mentioned.

The features of claims 12 and 13 serve the rapid and especially even mixing with water or other, especially liquid additives. in the The entire mixing tube with a uniform distribution of such nozzles. It has to be attached to the lower area of the mixing tube proved to be particularly advantageous in practice.

The design of all articulations ent speaking the features of claim 15 is manufacturing technically simple and especially inexpensive hand available and has proven to be practically advantageous. In the game to be realized here, on the one hand, the from the design data of the eccentric screw pump in the essential dependent sufficient agility ge be there, but on the other hand there is this flexibility be limited in that there is no touching of the stirring tool with the inner walls of the mixing tube is coming.

The invention will now be described with reference to the embodiment shown in the drawings are explained. Show it:

Fig. 1 is a schematic representation of the entire device before in a side view;

Fig. 2 is a side view of the stirring;

Fig. 3 is an end view of the stirring tool in a plane III-III of Fig. 2;

Fig. 4 is a view of the stirring tool of Figure 2 in a plane IV-IV.

Fig. 5 is an illustration of a nozzle of the mixing tube in partial section.

1 designates a mixing tube which is inclined downward at an angle of 10 ° to 15 ° relative to a horizontal plane and on which a funnel-shaped container 2 containing the building material is mounted. A slide 3 separates the mixing tube 1 from the container 2 .

In the area of the inlet opening 4 in the mixing tube 1 , a tightly fitting rubber screw 5 is arranged in this, through which the building material is conveyed into the actual mixing chamber 6 . The mixing chamber is armored with thick-walled, highly wear-resistant, smooth plastic over its entire length, including that of a pump inlet funnel 7 . The mixing chamber 6 is provided with at least one mixed water nozzle 8 , wherein at least one cleaning nozzle, not shown in the drawing, can additionally be seen in the area of the pump inlet funnel 7 . Practically, several mixed water nozzles 8 can be attached along the axial extension of the mixing tube 1 . At an end of the mixing tube 1 attached flange 9 , an eccentric screw pump 10 is fastened in a manner not shown in the drawing. There are the mixed water nozzles 8 at the eccentric screw pump 10 facing the end of the mixing tube 1 , preferably at its lower area.

The eccentric screw pump 10 is driven by a motor 11 via a shaft which is divided several times by articulated connections. There is a first joint 12 between the motor 11 and the end thereof facing the rubber screw 5 . Further joints 13, 15 are located between the other end of the rubber screw 5 and one end of a stirring tool 14 and between the other end of the stirring tool 14 and the eccentric screw pump 16th All joints 12 , 13 , 15 can be formed in the simplest case very advantageously by pairing elements of outer and inner square profiles, which are provided with a corresponding game.

The rubber screw 5 ends at its end facing the motor 11 in a closed disk, not shown in the drawing, through which a backflow of the dry material is prevented. The rubber screw extends in the area of the mixing tube 1 over a length of at least two screw flights into it as well as over the plastic armor located within it, in order to avoid any splashing back of water into the dry area.

Due to the articulated connection between the eccentric screw pump 10 and the stirring tool 14 , the eccentric movement of the eccentric screw pump is not hindered during operation of the device. The eccentric screw pump 10 is operated at a relatively low speed, which for example in a range of 160 revolutions / min. up to 200 revolutions / min. lies, so that the mixing chamber 6 can be dimensioned much larger than the previously known with the same throughput in diameter. It can also be almost twice the length.

The dry material introduced into the funnel-shaped container 2 of the device gels exclusively under the influence of gravity through the inlet opening 4 into the mixing tube 1 and is conveyed by the rubber screw 5 into the mixing chamber 6 . The mixed water nozzles or the mixed water nozzle 8 act / cooperate with an automatically working device for metering the water to be mixed, not shown in the drawing, so that a defined admixture of an injected water takes place in the mixing chamber 6 , the material now mixed with water by the Eccentric screw pump 10 is pumped further. However, the subject of the invention also enables the pumping and possibly necessary remixing of premixed wet mortar, so that the mixed water nozzles 8 can also be used to add additives.

The stirring tool 14 shown only schematically in FIG. 1 will be explained in more detail below with reference to FIGS. 2 to 4.

The stirring tool 14 , the longitudinal axis of which is denoted by 16 in FIGS. 2 and 4, essentially consists of two scraper bars 17 which extend at the same distance - opposite one another - parallel to the longitudinal axis 16 . A with respect to said longitudinal axis 16 radially extending web 18 connects one end of the stripping bar 17 , while the other ends of which are also radially extending web parts 19 are attached to a bearing body 20 , through which the longitudinal axis 16 extends. It is the bearing body 20 in the embodiment shown towards the longitudinal axis 16 with respect to its outer contours rotationally symmetrical.

For the articulated connection of this stirring tool 12 with the rubber screw 5 on the one hand and the eccentric screw pump 10 on the other hand, a square mandrel 21 is fastened to the outside on the web 18 , while a square hollow section 22 is incorporated into the bearing body 20 . The square mandrel 21 and the square hollow section 22 represent functional elements of the joints 13 , 15 .

The joints 12 , 13 , 15, which are essentially the same as each other, are thus formed overall by element pairs consisting of square mandrels 21 and square hollow sections 22 , each of which is dimensioned with a certain play, by means of which sufficient angular mobility in the area of the joints is ensured .

The stripping bars 17 are formed in the embodiment shown, for example, in cross-section essentially square and - seen in the direction of rotation of the stirring tool 14 - pivoted about their respective longitudinal axis in the same sense. In principle, however, stripping bars 17 with a rectangular cross section can also be used here.

23 16 facing sides of the scraper bar 17 are two, to the, longitudinal axis of the fixed, rectangular in cross-section, is designated generally radially inwardly extending stirring arms, which end at a certain distance in front of the longitudinal axis of the sixteenth The stirring arms 23 have an approximately equal distance from the web 18 on the one hand and the web parts 19 on the other. They are preferably attached to the stripping bar 17 by welding.

24 with a conveying helix is referred to, which is attached to the, the eccentric screw pump 10 facing end of the agitator 14 , namely on the bearing body 20 . The conveying spiral 24 consists of two spiral-like parts 25 , 26 arranged opposite one another at a distance, by means of which uniform material conveyance in the direction of the eccentric screw pump 10 is ensured.

The stripping bars 17 are used to loosen or prevent material deposits in the peripheral region of the mixing chamber 6 . If necessary, more than two stripping bars 17 can also be provided. Also, by the web parts 19 axially projecting sections of the stripping bar 17 is contributed to a uniform material feed towards the eccentric screw pump.

Through the bilateral articulated coupling of the agitator tool 14 is achieved, among other things, that the movement of the eccentric screw pump is not hindered, so that the couplings formed by the designated square profiles couplings must have the necessary mobility of the agitator tool 14 corresponding game. However, this game is limited by the condition that the stirring tool must not come into contact with the inner wall of the plastic-armored mixing chamber 6 .

The four in the described embodiment Edge-formed joints can in principle also through other polygonal profiles or other joint con structures are replaced by comparable ones kinematic boundary conditions with regard to the angles mobility can be met.

Since the eccentric screw pump rotates relatively slowly in the device according to the invention, correspondingly high torques must be transmitted via the stirring tool 14 . In addition, an axial force developed by the eccentric screw pump 5 during its operation must be transmitted by the stirring tool 14 , which acts in the opposite direction to the conveying direction, so that overall the stirring tool must also be dimensioned from the point of view of rigidity.

5 with 27, the metallic wall of the mixing is shown in Fig. 6 denotes chamber, the inside armor material with a plastics coated 28th The mixed water nozzle 8 is inserted into an opening which penetrates the wall 27 and the plastic armor 28 and is formed in this area by a tubular element 29 . The end of this tubular element facing the mixing chamber 6 carries an external thread section onto which a ring component 30 which tapers conically in the direction of the wall 27 is screwed on.

The water nozzle 8 including the ring component 30 are arranged flush in the plastic armor 28 .

31 with a nut is designated, which is screwed onto a further external thread section of the tubular element 29 and bears on the outside against the wall 27 . By pulling this nut 31 , the ring member 30 is thus drawn into the rubber armor 28 , so that not only a tight fit of the water nozzle 8 but at the same time a reliable seal is given, in particular the space between the wall 27 and the plastic armor 28 against the interior the mixing chamber 6 .

With 32 a known coupling element for connecting a water or other liquid line is designated.

Claims (15)

1. Device for the continuous mixing of a building material with water in a stirring tool ( 14 ), in particular a mixing helix containing, fed by a conveyor mixing tube ( 1 ), to which an eccentric screw pump ( 10 ) is approximately coaxially connected, the shaft of the stirring tool ( 14 ) at the same time drive shaft for the eccentric screw pump ( 10 ), the conveyor screw ( 5 ), preferably made of rubber, with the mixing tube ( 1 ) on the opposite side of the eccentric screw pump ( 10 ) approximately coaxially connected and a common motor ( 11 ) is provided for driving the screw conveyor ( 5 ) of the stirring tool ( 14 ) and the eccentric screw pump ( 10 ), the shaft of the screw conveyor ( 5 ) serving as a drive shaft for the shaft of the stirring tool ( 14 ) and wherein Axis of the mixing tube ( 1 ) approximately horizontal, preferably at an angle of 10 ° to 15 ° with respect to the horizontal plane in Förde Direction is inclined downwards, characterized in that for conveying the building material by gravity to the mixing tube ( 1 ) containing the building material, funnel-shaped loading container ( 2 ) above the mixing tube ( 1 ) in the region of the screw conveyor ( 5 ) is arranged and that the shaft of the stirring tool ( 14 ) is articulated both with the eccentric screw pump ( 10 ) and with the shaft of the screw conveyor ( 5 ). 2. Device according to claim 1, characterized in that the mixing tube ( 1 ) at least in the mixing area ( 6 ) is thick-walled with highly wear-resistant, smooth plastic material. 3. Apparatus according to claim 1 or 2, characterized in that the stirring tool ( 14 ) has at least one, preferably parallel to the longitudinal axis ( 16 ) he extending stripping bar ( 17 ). 4. Device according to one of the preceding claims 1 to 3, characterized in that the stirring tool ( 14 ) on its, the eccentric screw pump ( 10 ) facing side carries a conveyor spiral ( 20 ). 5. The device according to claim 4, characterized in that the conveyor helix ( 20 ) is designed divided and is preferably formed by at least two mutually opposite spaced helical parts ( 25 , 26 ). 6. Device according to one of the preceding claims 3 to 5, characterized in that the stripping bar ( 17 ) extends axially beyond the feed spiral ( 20 ). 7. Device according to one of the preceding claims 3 to 6, characterized in that at least one stirring arm ( 23 ) extends radially inward from the stripping bar ( 17 ). 8. The device according to claim 7, characterized in that the stirring arm ( 23 ) ends at a distance from the longitudinal axis ( 16 ) of the stirring tool ( 14 ) and that preferably two scraper bars ( 17 ) are provided, each with at least one, radially inward extend the stirring arm ( 23 ) are equipped. 9. Device according to one of the preceding claims 3 to 8, characterized in that the stripping bars ( 17 ) in cross-section square or rectangular out stalt and with respect to the direction of rotation of the stirring tool ( 14 ) are arranged rotated in the same direction with respect to their respective longitudinal axis. 10. Device according to one of the preceding claims 3 to 9, characterized in that the Abstreifbal ken ( 17 ) are held by substantially radially extending webs ( 18 , 19 ) on which functional elements for articulated connection with the rubber screw ( 5 ) on the one hand and the eccentric screw pump ( 10 ) on the other hand are attached. 11. Device according to one of the preceding claims 3 to 10, characterized in that the stirring arms ( 23 ) have a rectangular cross section, the broad sides of which are arranged parallel or at an angle to the longitudinal axis ( 14 ) of the stirring tool ( 14 ). 12. Device according to one of the preceding claims 1 to 11, characterized in that a plurality of nozzles ( 8 ) for introducing water - preferably in a uniform distribution - are attached along at least part of the length of the mixing tube ( 1 ). 13. The apparatus according to claim 12, characterized in that the nozzles ( 8 ) in the, the eccentric screw pump ( 10 ) adjacent portion of the mixing tube ( 1 ) and are preferably arranged on the underside thereof. 14. Device according to one of the preceding claims 1 to 13, characterized in that the motor ( 13 ) with the screw conveyor ( 5 ) is articulated in connection. 15. The device according to one of the preceding claims 1 to 14, characterized in that preferably all articulated connections through play Element pairs of square or other polygon profiles are formed.