EP0584573B1 - Device for making pumpable mortar on the building site - Google Patents

Abstract

A screw mixing device (4) which can be charged with dry material is followed coaxially by a screw pump (7). The screw mixing device (4) and the screw pump (7) have a common drive unit (6, 6a). The common axis, directed obliquely upwards in the conveying direction, encloses an angle of between 10 DEG and 30 DEG with the horizontal. The mixing element (5) of the screw mixing device has a first section designed essentially for conveying the dry material as far as a water connector (11) and a second section designed for mixing the dry material with the water. The dry material may be dry mortar or only binder. In the latter case, the screw mixing device (4) has, at the level of its second section, an opening at the top for charging with sand. <IMAGE>

Description

The invention relates to a device for the construction site Production of pumpable mortar compounds with which in the Identical generic terms of claims 1 and 2 specified Characteristics.

Such a device is known from AT-B-385 309. The first section of your mixing organ consists of a continuous rubber screw with six complete turns. The second section is called a mixing helix, however, only includes a number of narrow radial wings on the shaft of the screw mixer. This well-known Device is used for high-pressure delivery of rigid plastic, homogenized building materials. The known device is however not for the production of pumpable mortar compounds different consistency in optimal product quality suitable.

The same applies to an even greater extent for those from DE-A-1 684 048 known device for mixing and conveying Gypsum that a storage tank with special internals and includes a uniform screw mixing element and for that reason alone for building materials still to be homogenized, in particular Mortar compositions of different consistency, not suitable is.

The invention has for its object a device of the genus specified in the introduction so that they both for the production of pumpable mortar compounds thicker consistency like spray plaster as well as for Manufacture of building materials with a more fluid consistency such as Self-leveling screed is suitable.

According to the invention, the same basic device can be used for this are used if their mixing element for the production of Spray plaster according to the characterizing part of claim 1 and for the production of liquid screed in accordance with the mark of Claim 2 is formed. Depending on the purpose of the The device therefore only needs the mixing element and the screw pump to be replaced, the latter because a needs-based promotion of the viscous plaster requires a more powerful screw pump than required in the case of the thinner liquid screed is.

An advantageous development of the device that both cleaning and retrofitting is accelerated specified in claim 3.

The embodiment according to claim 4 makes one special uniform loading of the mixing element with the dry mortar achieved and thereby improves the mixing quality.

The device according to claims 1 to 4 needs ready to use dry material premixed with sand, the e.g. comes from a silo installed on the construction site, under its outlet the device with its filling funnel is positioned. Among other things because of the transport costs is this delivered ready to use, 50% of dry material consisting of sand is more expensive than on the construction site in the same ratio of sand and binder (e.g. formulations based on cement and / or Anhydrite) produced mortar compositions. That is what she claims 5 specified further development of the device invoice, because it is also partly for the production of pumpable Mortar compositions, especially liquid screed, from dry Binder and sand added separately can be used.

This inventive Improvement of the previously explained, with ready to use dry material premixed with sand working device is based on the knowledge that when the throughput (the conveying capacity) of the Worm pump is greater than the delivery rate of the upstream mixing device, the mixing zone only partially is filled with material. The mixing zone contains that is, air-filled cavities, often in the form of one another separate air cushions that match the required Have the amount of sand filled to a certain extent. Surprised is that despite the very short Mixing section produce a homogeneous, pumpable mortar leaves. Basically, those for the infeed the air cavities required by the sand create that at a given drive speed common shaft of the screw mixer and the Worm pump a made of dry mortar and water, continuous flow of mortar mass Screw pump against such a higher delivery rate is exchanged. However, it is more advantageous only increase the drive speed accordingly. It has shown that from a certain speed to the from the hopper into the screw mixer amount of material conveyed - counter what you'd expect - essentially constant remains, especially if it is very fine-grained Material acts so that by increasing the speed only the delivery rate of the screw pump is increased, creating the required air gaps be created. Depending on the design of the diameter the screw mixing device and the geometric shape the mixing effect of which occurs, e.g. at a speed of 200 rpm, so that an increase the speed above this value to the desired air cushion leads in the binder / water mixture.

According to claim 6 is above that in the jacket Screw feed device provided sand feed opening a sand feed hopper is arranged.

The required amount of sand can be in the sand feed hopper to be shoveled. A constant mix ratio however, this is difficult achieve. Therefore, it is preferred according to claim 7 that the sand loading hopper has a tubular funnel neck and that in the funnel neck a sand screw conveyor is provided by means of an above of the sand loading funnel arranged gear motor is drivable. With the sand screw conveyor, one can sand scrapers following the course of the inner wall of the funnel or another stirrer combined for this ensures that the possibly damp sand sags evenly. The speed of the sand screw conveyor is determined so that the desired mixing ratio, e.g. 1: 1, from binder to sand.

The sand feed hopper can be used in any way, e.g. also automatically using from a silo known level indicator in the funnel with sand be kept filled. An easier way is specified in claim 8 and provides that at the inlet opening a metering conveyor belt of the sand feed hopper for the sand ends. Suitable dosing conveyor belts are known per se. You have on the task page a shaft into which the sand e.g. is shoveled. A cross-section that can be adjusted via a gap can be that of the one running at constant speed Adjust the belt for the amount of sand removed per unit of time.

It is recommended that the discharge end of the metering conveyor belt trained to be connectable with the sand hopper. This is possible according to claim 9 in such a way that the Sand loading hopper arranged with a vertical central axis is and a bracket rotatable about its central axis for the delivery end of the metering conveyor belt, on which also the gear motor for the sand auger is mounted. The bracket can thus in the after brought to the local situation in which the metering conveyor belt is located.

Fig. 1

eine teilweise im Schnitt gehaltene Seitenansicht einer Vorrichtung, die zur Beschickung mit Trockenmörtel ausgebildet ist,

Fig. 2

ein für die Herstellung von Spritzputz oder Mauermörtel geeignetes Mischorgan für die Vorrichtung nach Fig. 1,

Fig. 3

ein für die Herstellung von Fließestrich geeignetes Mischorgan für die Vorrichtung nach Fig. 1, und

Fig. 4

eine der Darstellung in Fig. 1 entsprechende Seitenansicht einer weiterentwickelten Vorrichtung, die auch wahlweise mit Bindemittel und Sand beschickt werden kann.

In the drawing, the devices according to the invention are shown schematically simplified in, for example, selected embodiments. It shows:

Fig. 1

FIG. 2 shows a side view, partly in section, of a device which is designed for charging with dry mortar,

Fig. 2

a mixing element suitable for the production of spray plaster or masonry mortar for the device according to FIG. 1,

Fig. 3

a suitable for the production of liquid screed mixing element for the device of FIG. 1, and

Fig. 4

a side view corresponding to the representation in Fig. 1 of a further developed device, which can also be optionally loaded with binder and sand.

1 is the funnel-shaped Outlet 1 of a dry mortar silo, not shown in the rest via an elastic intermediate piece 2, e.g. a short section of hose or an elastic one Bellows, with an opening in the lid 3a of a hopper 3 connected to a screw mixer 4 opens. The screw mixing device 4 contains a Mixing element 5, which is shown in Figure 2, but optionally also against the mixing element shown in FIG. 3 9 is interchangeable. The mixing element 5 is one only schematically indicated electric motor 6 with a downstream Gear 6a with a constant speed of can be driven a few hundred revolutions per minute. On is the exit side of the screw mixer 4 a screw pump 7 flanged to a known type, whose screw conveyor rotates with the mixing element 5 is connected. The screw pump 7 delivers in Direction of a pipe or hose 8 leading to Location leads. The screw mixing device 4 and the pusher pump 7 are therefore coaxial with one another along an axis falling in the conveying direction arranged with the horizontal an angle α between Includes 10 ° and 30 °.

The device as a whole is only symbolic indicated chassis 10 mounted. For transportation the elastic intermediate piece 2 either from the silo outlet 1 or detached from the shaft 3.

To prevent the dry mortar from the silo falls directly into the screw mixer 4 (which is too Malfunctions), the funnel 3 a wall 3b acting as a slide. This essentially transverse to the conveying direction, adjacent to the motor 6 Wall 3b therefore closes with the vertical Angle β e.g. in the range of 30 ° to 50 °. The filling opening is in the cover 3a of the funnel 3 above the wall 3b, so that the dry mortar from first meets wall 3b above and then lengthways this slides down into the screw mixing device 4. There it is first mixed in by the mixing element 5 Direction of a symbolized by a connecting piece 11 Promoted water supply, then thoroughly with Water mixed and partly under the influence of the Mixing organ 5, partly under the influence of gravity fed to the screw pump 7. Meanwhile, over the water connection piece 11 and a symbolic representation Line 12 water from a metering device 13 fed in continuously in metered quantities. The dosing device 13, of any known type can be with the local water network Solenoid valve 14 connected, the same time as a pressure reducing valve can be trained.

In addition to the metering device 13 there is symbolically an electrical one Control cabinet 15 indicated the total device controls, especially depending on that Output signal of a on or in the funnel 3 at a more suitable Position arranged level detector 16. This ensures that the funnel 3 is always sufficient Dry mortar is filled. The level indicator can be used for this 16 e.g. switching on a vibrator in the above the silo or opening a slide Trigger at the silo outlet when the specified fill level is below. These details are there known and not part of the invention, not shown.

Despite its simple structure, the device according to Figure 1 plaster or masonry mortar as well as liquid screed getting produced. This is achieved through the use of materials adapted to the respective material specially designed mixing elements that are very easy against each other are interchangeable, along with that in everyone If it is necessary to replace the worm pump 7, the in the case of the production of plaster or masonry mortar must be much more efficient than in the case of the Production of liquid screed, since the latter is less viscous Consistency as e.g. Spray plaster is. For easy Interchangeability of the mixing element is that from the electric motor 6 and the transmission 6a existing drive unit pivotable with the housing of the screw mixing device 4 connected (not shown). Besides, is the mixing element with both the shaft of the drive unit as well as with the drive side of the screw conveyor the worm pump 7 with simple claws connected.

The mixing element 5 shown in FIGS. 1 and 2 is used to produce plaster or masonry mortar. It 2 comprises a first section 51 for this purpose a continuous screw 50 with about 3½ turns and a second section 52 of approximately the same length Segments 53 of a screw from the former Snail with a larger pitch. By the relative large slope of the screw segments 53 of the second section 52, a particularly good mixing effect is achieved. At the same time prevent the preferably periodic Gaps 54 that this big slope too a correspondingly high conveying speed in the axial Direction. Due to a too high conveying speed the mixing time would be too short to to achieve homogeneous mixing. Important for the function is also an axial land 55 which defines the peripheral edges axially consecutive segments 53 connects and forms a wall scraper. The first paragraph 51 corresponds essentially to the dry area of the Screw mixing device 4, the second section 52 their wet area.

In contrast, the mixing element 9 shown in FIG. 3 serves for the production of liquid screed. It includes also two functionally different sections. The first section 91 has individual, flat mixing blades 90, each against the radial plane around one of the (like 2 from right to left) Direction of conveyance and the desired conveying speed adjusted angles are set. This concludes the second section 92 corresponds to the wet area and consists of similar mixing blades 93, from which each have two in the same axial plane, Adjacent mixing blades form a pair, the peripheral areas are connected via an axial web 95. All in all four such webs 95 are provided, the evenly distributed over the circumference of the mixing element 9 arranged and by a web length in the axial direction are offset. The function of the webs 95 corresponds that of the web 55 in Figure 2. The compared to Figure 2 large spaces 94 between the mixing blades 90 to 93 are on the relatively thin consistency of liquid screed, so prevent one too high pressure build-up at the inlet of the screw pump 7 in Figure 1

At the two ends of the mixing elements 5 in FIG. 2 and 9 in FIG. 3 shows the drive and driven side Coupling elements in the form of web-like or claw-like Carriers 41 and 42.

4 is a further development of the device shown in Fig. 1. This advanced device is used to produce pumpable mortar compounds from binder and sand, in particular for production of liquid screed. That is why the screw mixing device 4 here with the mixing element 9 according to FIG. 3 equipped. All other, already shown in Fig. 1 Parts of the device are the same Reference numerals as provided there. However, while the device 1 with their feed chute 3 with Ready-to-use dry mortar 4, the device according to FIG. 4 is primarily for on-site production of a pumpable Mortar mass, here liquid screed, made of binder and sand intended. The binder comes from an above the funnel-shaped outlet 1 silo to be presented. Of the Sand comes from the construction site and is fed via a sand feed hopper 20 added, the tubular Neck 20a above an opening 4a in the jacket of Screw mixing device 4 opens. The opening 4a is located downstream of the water connection pipe 11.

The funnel 20 is detachable on a box-shaped attachment 21 mounted.

The sand is only symbolic to the funnel 20 by means of a illustrated, known metering conveyor belt 22 fed from a funnel-shaped as a rule Feed chute 23 removes sand in a quantity, the one in the direction of the double arrow shown adjustable aperture 23a is adjustable. The Metering conveyor belt 22 is supported with its discharge end on a bracket 24 which is rotatable (not shown) is arranged on the upper edge of the funnel 20 and also carries a geared motor 25 which one in the sand conveyor screw 26 arranged on the funnel neck 20a drives. This has a web on its inlet side 26a, which is a short distance parallel to the inner wall of the sand loading hopper 20 extends and, since it rotates with the sand conveyor screw 26 as a sand scraper works. The speed of the geared motor 25 and thus the sand screw 26 is selected so that the desired mixing ratio of e.g. 1: 1 of binder results in sand. This speed can range from 40 to 60 rpm, while the speed of the drive unit 6, 6a, which supplies the binder, a value of can have, for example, between 200 and 400 rpm. The sand feed hopper via the metering conveyor belt 22 20 supplied amount of sand is set so that there is always enough sand in the latter.

4 can of course also with ready-mixed pre-mixed dry mortar be loaded. The previously described Parts for feeding sand are then inoperative. The sand loading hopper 20 can be in place remain or detached from the attachment 21 and this be closed by an appropriate cover.

Claims (9)

1. Apparatus for the production of pumpable mortar materials, on a building site, comprising a screw mixing apparatus (4) to which dry material can be continuously fed by way of a filling hopper (3) and to which a metered amount of water can be continuously fed by way of a connection (11) which follows the filling hopper in the conveying direction, and a screw pump (7) which is connected downstream of the screw mixing apparatus (4), wherein the screw mixing apparatus (4) and the screw pump (7) are arranged coaxially one behind the other along an axis which falls in the conveying direction and which includes an angle (α) of between 10° and 30° with the horizontal, the screw mixing apparatus (4) and the screw pump (7) have a common drive unit (6, 6a), and the mixing member (5; 9) of the screw mixing apparatus includes two portions (51, 52; 91, 92) of which the first portion (51; 91) is adapted substantially for conveying the dry material to the water connection (11) and the second portion (52; 92) is adapted for mixing the dry material with the water, characterised in that for the production of spray plaster the first portion (91) of the mixing member (5) comprises a continuous screw (50) with two to four turns, and that the second portion (52) comprises a periodically interrupted screw of approximately the same length but greater pitch with two to three turns and an axial bar (55) which connects corresponding peripheral regions of axially successive screw segments (53) and which forms a wall scraper.
2. Apparatus for the production of pumpable mortar materials, on a building site, comprising a screw mixing apparatus (4) to which dry material can be continuously fed by way of a filling hopper (3) and to which a metered amount of water can be continuously fed by way of a connection (11) which follows the filling hopper in the conveying direction, and a screw pump (7) which is connected downstream of the screw mixing apparatus (4), wherein the screw mixing apparatus (4) and the screw pump (7) are arranged coaxially one behind the other along an axis which falls in the conveying direction and which includes an angle (α) of between 10° and 30° with the horizontal, the screw mixing apparatus (4) and the screw pump (7) have a common drive unit (6, 6a), and the mixing member (5; 9) of the screw mixing apparatus includes two portions (51, 52; 91, 92) of which the first portion (51; 91) is adapted substantially for conveying the dry material to the water connection (11) and the second portion (52; 92) is adapted for mixing the dry material with the water, characterised in that for the production of flowable floor finishing material the first portion (91) of the mixing member (9) comprises individual flat mixing blades (90) which are each set relative to the radial plane at an angle which is adapted to the conveying direction and the conveying speed, and that the second portion (92) comprises similar mixing blades (93), of which each two adjacent blades disposed in the same axial plane form a pair whose peripheral regions are connected by way of an axial bar (95), and that at least two such bars (95) are arranged displaced through about 180° in the peripheral direction and preferably by a bar length in the axial direction.
3. Apparatus according to claim 1 or claim 2 characterised in that for easy interchangeability the mixing member (5; 9) of the screw mixing apparatus (4) is in engagement by way of dogs (41, 42) with the shaft of the screw pump (7) and with the shaft of the drive unit (6, 6a) respectively and that the drive unit (6, 6a) is connected to the housing of the screw mixing apparatus (4) in such a way that it can be pivoted away or quickly released.
4. Apparatus according to one of claims 1 to 3 characterised in that for the feed of the dry material the wall (3b) of the filling hopper (3), which extends substantially transversely with respect to the conveying direction and which is adjacent to the drive unit (6, 6a) is inclined through an angle (β) of about 30° to 40° relative to the perpendicular so that the hopper (3) increases in size in an upward direction, and that the hopper (3) has a filling opening whose projected surface falls on to said inclined wall (3b).
5. Apparatus according to one of claims 1 to 4 wherein the dry material only comprises binding agent characterised in that at the level of the second portion (52; 92) of its mixing member (5; 9) the screw mixing apparatus (4) has an opening (4a) for charging with sand in its tubular casing at the top thereof.
6. Apparatus according to claim 5 characterised in that a sand charging hopper (20) discharges into the sand charging opening (4a).
7. Apparatus according to claim 6 characterised in that the sand charging hopper (20) has a tubular hopper neck (20a) and that provided in the hopper neck (20a) is a sand conveyor screw (26) which is drivable by means of a motor-transmission unit (25) arranged above the sand charging hopper (20).
8. Apparatus according to claim 6 or claim 7 characterised in that a metering conveyor belt (22) for the sand ends at the intake opening of the sand charging hopper (20).
9. Apparatus according to claim 8 characterised in that the sand charging hopper (20) is arranged with its centre line vertical and carries a holder (24) rotatable about said centre line for the discharge end of the metering conveyor belt (22), on which holder the motor-transmission unit (25) for the sand conveyor screw (26) is also mounted.

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