NL2008599C2 - Building block production installation with stirring organs having axes of rotation extend in a moving direction of a charging trough. - Google Patents

Abstract

The plant (1) has a loading trough (2) fastened to a carrier (10), so that the carrier and the trough are movable together in a direction from an unloading position in which an outlet opening (15) of the trough lies above a filling opening (27) of an arrangement of mold cavities (26). Rotatable agitating bodies (16) are positioned adjacent to each another above the outlet opening in the trough. The bodies are rotated by drive units (11) i.e. electromotors, where rotational axles of the bodies extend into a direction running parallel to a traveling direction (V) of the carrier. The plant comprises a supply unit for providing a curable building block mixture i.e. sand limestone mixture. An independent claim is also included for a method for operating a building block manufacturing plant.

Description

Title: Building block production installation with stirring organs having axes of rotation extend in a moving direction of a charging trough.

P30624NL01/RR

The invention relates to the production of building blocks, in particular the 5 production of sand-limestone building blocks, also referred to as calcium silicate building blocks.

For the production of sand-limestone building blocks it is known to use a production installation which comprises a large steel manufacturing mould which delimits an assembly of upstanding rectangular mould cavities. In the downwards direction the cavities are 10 delimited by lower punches of a hydraulic press. At their upper side the cavities each have a complementary shaped rectangular filling opening. At a position sideways of the mould and press, a supply of sand-limestone mixture is provided. A carriage with a charging trough is moveable by means of a drive unit in the horizontal direction between a charging position in which the trough is filled with the mixture out of the supply, and a discharging position in 15 which the mixture contained in the trough is emptied inside the mould cavities. For this the charging trough has an outlet opening at its bottom which in the discharging position gets positioned above the filling openings. Inside the charging trough, at a position directly above the outlet opening, two rectangular stirring frames are mounted side by side which can be driven in rotation by means of a common drive unit. The stirring frames extend in the 20 horizontal sideways direction over the outlet opening. After the mould cavities have been sufficiently filled, the mixtures are compressed therein by means of the hydraulic press. For this the hydraulic press not only comprises said lower punches, but also an upper set of punches which are lowered as soon as the carriage and charging trough are moved sufficiently away back to its charging position underneath the supply. After the compressing 25 has ended, the compressed mixtures already have the form of the aimed building blocks and only have to be cured. For this they are pushed out of their mould cavities by the lower punches and are then transported towards an autoclave for curing therein for a certain period of time under the influence of pressurized hot steam.

A disadvantage with this known installation is that sometimes the quality of the 30 manufactured building blocks leaves to be desired. In particular it has appeared in practice that certain edge areas of the building blocks tend to have lower density of the sand-limestone mixture compared to the rest of the block. Because of this the compression strength of the block then may also be lower in those critical edge areas, making the block rather fragile to get damaged. In order to overcome this problem on the one hand it is 35 possible to add more lime to the mixture, because this enhances the strength of the mixture -2- after curing. This however makes the blocks more expensive. On the other hand it is possible to compress the mixtures inside the mould cavities at higher pressures, because this also enhances the strength of the mixture after curing. This however takes more time and is limited by the maximum capacity of the hydraulic press.

5 Another disadvantage that has appeared with the present installation is that sand- limestone mixture sticks to the stirring frames. This may lead to unpredictable and/or improper filling degrees of the mould cavities. It has even appeared that air gets trapped inside the cavities and stands in the way to a complete and uniform filling of the cavities. In order to overcome this it has even been tried to add an extra discharging step in which the 10 charging trough is moved once again from its charging towards its discharging position with a new batch of the mixture inside its trough to get discharged into the mould cavities. The sticking of sand-limestone mixture to the stirring frames may also lead to segregation of the mixture inside the trough and thus to inhomogeneous mixtures being discharged into the cavities. This also may have a negative influence on the strength of the end product.

15 FR-1.261.590 shows an installation for the filling and subsequently pressing of a so- called “breaking” stone element. This breaking stone element is manufactured out of concrete and is made as a square with four equal sides having a pattern of grooves extending in between those sides. The grooves form breaking lines along which the element can be broken after it has been hardened, such that small stones with somewhat rough 20 breaking surfaces are obtained. The installation comprises a carriage with charging trough which together are movable between a concrete mixture reservoir and a mould cavity. The mould cavity comprises a matrix of upwardly projecting filling blocks. The trough comprises four stirring organs each provided with radially outwardly projecting fingers. The stirring organs extend in the moving direction of the carriage and are commonly driven by means of 25 a single electromotor.

JP-64-55004-U seems to show another example of an installation for manufacturing stone blocks which comprises a movable assembly of a carriage and charging trough with stirring organs extending in the moving direction of the carriage. Two of those stirring organs are provided which each comprise radially outwardly projecting fingers. The installation is 30 destined to manufacture two rectangular stone blocks at a time. For this two rectangular mould cavities are provided which have their long sides extending parallel to the moving direction of the carriage.

US-3,164,649 shows an installation for manufacturing blocks of ceramic or refractory material. The installation comprises a movable assembly of a carriage and charging trough 35 with four commonly driven stirring organs extending in the moving direction of the carriage. Each stirring organ comprises agitator pins positioned at acute angles. At its bottom the trough comprises a plurality of blow tubes via which pulverulent material can be blown into a -3- set of two rectangular mould cavities. The two rectangular mould cavities have their long sides extending parallel to the moving direction of the carriage.

For each of those abovementioned known three installations the production process still leaves to be desired, and in particular needs to be improved in order to make them more 5 suitable to deal with the manufacturing of large building blocks and/or other types of stone mixtures like sand-lime stone mixtures for the manufacturing of calcium silicate building blocks.

The present invention aims to at least partially overcome one or more of the above disadvantages, or to provide a usable alternative solution. In particular the invention aims to 10 provide a fully reliable building block production installation with which it is possible to obtain high-quality building blocks in a time-efficient and cost-saving manner.

This aim is achieved by a building block production installation according to claim 1. The installation comprises a charging trough which at the beginning of each filling cycle is to be filled with an amount of curable building block mixture, in particular sand-limestone 15 mixture. The charging trough has an outlet opening at its bottom and is mounted on a carriage. The assembly of carriage and trough is movable in a moving direction, in particular a substantially horizontal moving direction, to and from a discharge position. In this discharge position the outlet opening of the charging trough is positioned above at least one filling opening(s) of an assembly of one or more mould cavities delimited inside a 20 manufacturing mould. Inside the charging trough a plurality of rotatable stirring organs are positioned adjacent one another above the outlet opening. The carriage can be moved by means of a suitable drive unit, for example a piston-cylinder system. The stirring organs can be rotated respectively by means of suitable drive units, for example an electromotor for rotating the stirring organs. According to the inventive thought, the stirring organs are 25 positioned such inside the trough that their axes of rotation extend in a direction which is substantially parallel to the moving direction of the carriage.

This specific orientation of the stirring organs brings along a number of important advantages mostly because it makes it possible to more accurately and uniformly fill the cavities with the mixture. Owing to this, less drop out of building blocks occurs during the 30 manufacturing process. For example it makes it possible to first start filling the most critical areas of the one or more mould cavities, like corners portions and opposite edge areas thereof. Furthermore it has appeared that air can more easily escape out of the mould cavity or cavities owing to the fact that it is now possible to first empty the charging trough along its outermost edge sides. Furthermore, with this new orientation of the stirring organs it has 35 appeared possible to increase the speed of the stirring organs and thus to increase the filling speed of the cavities. Rotational speeds of the stirring organs of more than 90-160 rpm have appeared possible. Those high speeds help to keep the stirring organs clean from -4- adhering mixture particles, and helps to push the mixture forcedly into the cavities. This forcedly pushing the mixture into the cavities has the effect of already pre-compressing the mixture inside its cavity. This makes it easier to quickly compress the mixture to its desired end strength by means of a press organ after it has filled up the entire cavity.

5 Owing to the more accurate and pre-compressed filling of the cavities, height differences in the end product, that is to say height differences of the building blocks after curing, can be minimized with tenths of millimetres, to be more specific from less then 0,8 mm to less then 0,2 mm. Also it has appeared that a segregation of the mixture inside the trough is less likely to occur with this ne orientation of the stirring organs. This is particularly 10 advantageous when manufacturing high-density building blocks, like calcium silicate building blocks with high-density particles like basalt added thereto. Finally it is noted that no driving means, like a transmission needs to be provided alongside the side walls of the charging trough. A drive unit or drive units and transmission for the stirring organs can now advantageously be positioned directly in front or behind the stirring organs. Since the height 15 and width of the charging trough are mostly limited by the press organ, this positioning of the drive unit(s) and/or transmissions makes it possible to increase the width of the trough, and thus to increase the amount of mixture the trough can discharge during each movement to its discharging position. This makes it possible to fill larger cavities at shorter filling cycle times.

20 In an advantageous embodiment the installation is used in combination with a specific type and orientation of a manufacturing mould. In particular this mould is of the type having one or more elongated, mostly rectangular, filling openings at its upper side, with which the mould is orientated in such a way relative to the carriage that centre axes of the elongated filling openings extend in a direction which is substantially perpendicular to both 25 the axes of rotation of the stirring organs as well as to the moving direction of the carriage. Thus tangents of the rotational direction of the stirring organs come to lie in centre planes of the cavities. Owing to this a rotation of the stirring organs is well able to push mixture smoothly into the cavity in a direction parallel to the centre plane of the cavity. The tangents of the rotational direction do not interfere with the longitudinal side walls of the cavity.

30 Advantageously the mixture is not thrown against or over one of those side walls. The longitudinal side parts of the cavity in this way can easily get filled in the same uniform manner as the rest of the cavity.

In a further embodiment distinctive drive units have been provided for each of the stirring organs. Those drive units make it possible to separately drive the respective stirring 35 organs in different rotational directions and/or speeds whenever desired. The plurality of drive units can easily be positioned next to each other without delimiting the maximum possible dimensioning of the trough. A suitable control unit can be provided and -5- programmed such that depending on the type and dimension of the cavity/cavities and/or depending on progress of the filling cycle and/or depending on the composition of the mixture used, some of the stirring organs are driven or not, in a clockwise or counterclockwise direction, at high or at low speeds. This makes the installation very flexible during 5 filling and well adaptable to all kinds of circumstances.

In a preferred embodiment at least three, in particular at least four, stirring organs are positioned adjacent each other. The two most outermost stirring organs can then be specifically used for filling up the critical side edge areas of the cavities, whereas the one or more intermediate stirring organs can be used for filling up the less critical centre part of the 10 cavities.

The combination of providing individually drivable stirring organs with the providing of at least three stirring organs, advantageously makes it possible to have the two outermost ones driven at higher speeds, in particular at least 20% faster, than the intermediate one(s). For example, the outermost ones can then be driven at 100-150 rpm, whereas the innermost 15 one(s) are driven at 75-125 rpm. Thus the difficult to be filled corners along the short sides of the mould cavities can more easily be filled.

In addition to this or in the alternative it is possible to equip the outermost stirring organs with larger radii than the innermost stirring organs. This also has the effect of forcing relative higher amounts of the mixture into the direction of the corners along the short sides 20 of the mould cavities. For example the outermost stirring organs may have a radius of approximately 300 mm, whereas the innermost stirring organs may have a radius of 240 mm. Furthermore the combination of providing individually drivable stirring organs with the providing of an even number of at least four stirring organs, advantageously makes it possible to have sets of adjacent stirring organs rotate towards each other in opposing 25 directions. For example in the case of four stirring organs it is then possible to, seen from the front side of the carriage, have the left outermost stirring organ rotate clockwise, whereas the adjacent left inner stirring organ is rotated counter-clockwise, and to have the right outermost stirring organ rotate counter-clockwise, whereas the adjacent right inner stirring organ is rotated clockwise.

30 It is possible to have the stirring organs rotate during the entire forward and backward stroke of the carriage from the filling position towards the discharge position and back again. In practice it has appeared however that it might be advantageous to stop the stirring organs from rotating immediately or shortly after the backward stroke has begun. For example the stirring organs can be driven in rotation during the entire forward stroke and 35 during a first part of the backward moving over a distance of approximately 200mm.

Subsequently the stirring organs are stopped from rotating during the remaining last part of -6- the backward stroke. Thus it is easier to evenly and stably fill up a plurality of mould cavities positioned after each other in the moving direction.

In particular each of the stirring organs comprises a longitudinal shaft with radially outwardly projecting teeth. Those teeth can have all kinds of shapes, straight, curved or 5 hooked, and preferably form part of star shaped plate segments provided at intervals next to each other along the longitudinal shaft. The teeth add a mixing action to the mixture during filling. This helps to further improve the homogeneity of the mixture, which helps to improve the strength of the end product, that is to say the building block after compression and curing. Compared to the use of rectangular frames, the stirring organs with teeth need a 10 lower momentum for rotating through the mixture. This makes it possible to drive the stirring organs at high speeds, again helping to keep the stirring organs clean from adhering mixture particles, and helping to push the mixture forcedly into the cavities.

It is possible to make all of the outwardly projecting teeth and/or star shaped plate segments evenly thick, seen in the moving direction. In practice it has proven advantageous 15 to make the forward teeth and/or star shaped plates thicker than the backward ones. For example the forward ones can be made 20 mm thick, whereas the backward ones are made 12 mm thick. Thus it is easier to evenly fill up a plurality of mould cavities positioned after each other in the moving direction. Since the backward mould cavities are already partly being filled with mixture which is present underneath the stirring organs during the forward 20 stroke, the thicker teeth and/or star shaped plate segments at the front side help to transport higher amounts of mixture into the forward mould cavities in order to compensate for this.

Adjacent stirring organs with or without teeth preferably are positioned with their centre axis at such distances from each other that a small play, of for example a few mm’s to a few cm’s, remains free between their outer diametrical ends. Thus it can be prevented 25 that a too high degree of compacting of the mixture is obtained in between two adjacent stirring organs during rotation thereof which otherwise could lead to the forming of contamination in between and around them.

It is also possible for adjacent stirring organs with teeth to be positioned so close to each other that their teeth start gripping into each other during rotation. Preferably the teeth 30 of adjacent stirring organs then are positioned such along their longitudinal shafts that they lie staggered in the horizontal direction relative to each other. This makes it possible for the teeth to grip sideways into each other, that is to say come to lie in between each other. During rotation the teeth then slide alongside each other, which helps to keep the stirring organs relative clean form sticking mixture particles. Another advantage of using stirring 35 organs with meshing teeth is that they prevent large mixture particles to get passed them. Those large particles are crushed in between the adjacent stirring organs. Should such a crushing not be possible, for example because of a strange object present inside the -7- mixture, then the stirring organs are automatically blocked from rotation. Thus such large non-crushable strange objects are unable to penetrate into the cavities.

Further advantageous embodiments are stated in the subclaims.

The invention also relates to a use of the installation for the manufacturing of calcium 5 silicate building blocks, and to a method for operating the installation.

The invention shall be explained in more detail below, with reference to the accompanying drawings, in which:

Fig. 1 is a schematic sectional view of an embodiment of the installation according to the 10 invention with the carriage in the charging position used for the manufacturing of calcium silicate building blocks;

Fig. 2 is a view over the line ll-ll in fig. 1;

Fig. 3 is a view according to fig. 1 with the carriage in the discharging position;

Fig. 4 is a view over the line IV-IV in fig. 3; 15 Fig. 5 shows an enlarged side view of the assembly of carriage and charging trough of fig. 1-4;

Fig. 6 shows a top view of fig. 5;

Fig. 7 is a cross-sectional view over the line VII-VII in fig. 6;

Fig. 8 is a view according to fig. 6 of an alternative solution; and 20 Fig. 9 shows embodiments of the star shaped plate segments of fig. 8.

The entire building block production installation has been given the reference numeral 1 in fig. 1-4. The installation 1 comprises a charging trough 2 which at its upper side has an open construction such that it can be filled with sand-limestone mixture when placed 25 in a charging position underneath supply means 3. The supply means 3 comprise a drop chute 4 which is closable by means of an operable hatch 5. Premixed sand-limestone mixture is transported to the drop chute 4 via a conveyor 6. The trough 2 is mounted on top of a carriage 10 which is movable in the horizontal moving direction V by means of a piston-cylinder system 11 mounted between the carriage 10 and a frame 13 of the installation 1.

30 An upper part 2a of the trough 2 is equipped with downwardly sloping wall parts. A

lower part 2b of the trough 2 has a substantial rectangular shape, which at its lower side ends in a substantially rectangular outlet opening 15 (see fig. 5-7). In the lower part 2b four horizontally extending longitudinal stirring organs 16 are mounted. Each stirring organ 16 comprises a shaft 17 with a plurality of star shaped plate segments mounted on it 35 interspaced at regular intervals. The segments each comprise a number of, in this case four, radially outwardly projecting teeth 18. As can be seen in fig. 6 the outwardly extending teeth -8- 18 of adjacent stirring organs lie staggered in the horizontal direction relative to each other and grip sideways into each other without directly contacting each other.

For each stirring organ 16 an electromotor is provided as drive unit 20 for driving it in rotation. The drive units 20 lie near the outer ends of the stirring organs 16. Each of the 5 stirring organs 16 has its shaft 17, of which the centre axis corresponds to its axis of rotation 17a, extend in a horizontal direction which is parallel to the moving direction V of the carriage 10.

The installation 1 further comprises a shifting table 22 mounted to the frame 13. The carriage 10 is movable over this table 22 with the outlet opening 15 of the trough 2 sliding 10 over it. In front of the charging position of the trough 2, a manufacturing mould 25 is placed. The mould 25 in this case delimits four upstanding rectangular mould cavities 26 each having a complementary rectangular filling opening 27 at its upper side. The filling openings 27 are placed one behind the other (seen in the moving direction V), and have their centre axes 27a extend in a direction which is substantially perpendicular to the moving direction V 15 as well as perpendicular to the axes of rotation 17a of the stirring organs 16.

The mould 25 has a substantially flat upper side. The filling openings 26 lie at the same level as the upper side of the mould 25. The mould is placed at such a height inside the installation 1 that the upper side of the mould 25 connects smoothly to the table 22. In this way the trough can smoothly be shifted over the table 22 and upper side of the mould 20 25 without mixture already start leaking out of the trough 2.

A hydraulic press organ 30 is provided which has a lower set of punches 30a and an upper set of punches 30b. The lower and upper punches 30a, 30b are movable in the vertical direction and have cross-sectional dimensions which correspond to the cross-sectional dimensions of the cavities 26 and filling openings 27 such that they are able to 25 slide close-fitting through these cavities 26.

An advantageous example of a filling cycle which is possible with this installation 1, starts with a charging of the trough 2 with a batch of sand-limestone mixture by temporarily opening of the hatch 5 of the chute 4. Subsequently the carriage 10 is moved forward from out of its charging position as shown in fig. 1 and 2 until it reaches its discharging position as 30 shown in fig. 3 and 4. In this discharging position the outlet opening 15 of the trough 2 is placed directly above the filling openings 27. The assembly of filling openings 27 together has dimensions which are smaller than the dimensions of the outlet opening 15. After having stayed a few seconds in the discharging position, the carriage 10 is moved back again towards its charging position. Both during the forward moving, the stand-still and the 35 backward moving of the carriage 10, mixture is free to start flowing into the cavities 26 as soon as the outlet opening 15 starts to cover the filling openings 27. During filling, the lower punches 30a delimit the cavities 26 at their bottom sides. The upper punches 30b are -9- positioned at such a distance above the mould 25 that they do not stand in the way of the trough 2 being moved towards its discharging position. In order to enhance the filling process, some or all of the stirring organs 16 are driven to rotate in particular directions and at particular speeds. The stirring organs 16 thus are able to forcedly transport the mixture 5 from out of the trough into the cavities 26.

It has appeared advantageous if during the forward moving of the carriage 10, seen from the front side as shown in fig. 7, the outermost left stirring organ 16a is driven in rotation in the clockwise direction, whereas the outermost right stirring organ 16d is driven in rotation in the counter-clockwise direction. The other two organs 16b and 16c can then be 10 driven more slowly or even substantially held at a stand-still by not driving them during the initial stage of the forward movement. In this way it can be assured that first the most critical short sides of the cavities 26 get properly filled with the mixture. Subsequently the intermediate stirring organs can also be started to rotate or driven at higher speeds. For example the left intermediate organ 16b can then be driven to rotate in the counter-15 clockwise direction and the right intermediate organ 16c in the clockwise direction, as shown in fig. 7. Thus the less critical centre areas of the cavities 26 get filled in second instance. This can be started as soon as the short sides have gotten filled to a certain desirable level, which shall depend on the dimensions of the cavities 26, the composition of the mixture, etc. For example the driving of the intermediate organs 16b and 16c can be started as soon as 20 the carriage 10 starts moving backwards.

After the entire cavities 26 have been fully filled in this manner, and the trough 2 has been moved back into its charging position for receiving a new batch of the mixture, the upper punches 30b are lowered and pressed into the cavities 26. Thus the mixtures in the cavities 26 get compressed to a certain desired extent into uncured compressed building 25 blocks. Subsequently those compressed uncured building blocks can be pushed out of their mould cavities 26 by raising of the lower punches 30a while the upper punches 30b have already been moved back to their original lifted positions as shown in fig. 1. Finally the compressed uncured building blocks are transported towards an autoclave (not shown) where they are cured under the influence of pressurized steam.

30 Fig. 8 shows a variant embodiment in which four individually drivable stirring organs 80a-d are positioned adjacent each other. Each of the stirring organs 80a-d is equipped with star shaped plate segments 81a-d. With this the outermost stirring organs 80a, 80d are equipped with segments 81a, 81 d having a larger diameter than the segments 81b, 81c of the innermost stirring organs 80b, 80c. Furthermore the back side segments 81a’-d’ are 35 made thicker than the front side segments 81a”-d”. The central axes of the stirring organs 80a-d are positioned at equal intervals from each other, which together with the differing diameters has the effect that a larger play is left free in between the two innermost stirring - 10- organs 80b, 80c compared to the plays left free in between each outermost stirring organ 80a, 80d and its adjacent innermost stirring organ 80b, 80c. The outermost segments 81a, 81 d are positioned staggered relative to the innermost segments 81b, 81c.

Fig. 9a shows an advantageous embodiment of the large outermost star shaped 5 plate segments 81a, 81 d. As can be seen they comprise three somewhat curved teeth which are rounded at their outer ends. The teeth are preferably curved in the direction towards which the segments are to be rotated during discharge. This is possible if it is known upfront which direction this is going to be.

Fig. 9b shows an advantageous embodiment of the small innermost star shaped 10 plate segments 81b, 81c. As can be seen they comprise three substantially straight teeth which are rounded at their outer ends. The teeth here are not curved in order to make it possible to have the innermost stirring organs 80b, 80c rotate in either direction during discharge. If here it is also known upfront in which direction the innermost stirring organs 80b, 80c are going to be rotated, they can also be equipped with teeth which are curved in 15 the aimed particular rotational direction.

It is noted that the idea of using stirring organs with outwardly projecting teeth, which in particular may or may not mesh/grip sideways into each other, in the above type of installation, has already proven to be advantageous when the stirring organs extend in other directions relative to the moving direction of the trough, for example in combination with the 20 stirring organs extending in horizontal directions substantially perpendicular to the moving direction of the carriage, that is to say sideways inside the trough. Further it is noted that the idea of using a plurality of stirring organs which can each be driven individually by means of their own dedicated drive unit, in the above type of installation, has also already proven to be advantageous when the stirring organs extend in other directions relative to the moving 25 direction of the trough, for example in combination with the stirring organs extending in horizontal directions substantially perpendicular to the moving direction of the carriage, that is to say sideways inside the trough.

Besides the embodiments shown, numerous variants are possible. For example, the various parts and components can be given different shapes and dimensions. Instead of 30 using three or four teeth equally divided over the circumference of the cross-sectional segments of the stirring organ, it is also possible to use more or less teeth. It is also possible to use other types of stirring organs, like Archimedean screws or the conventional rectangular frames. Also other types of drive units can be used, or one common drive unit with a suitable steerable transmission for also being able to individually drive each of the 35 stirring organs. The invention is particularly advantageous for the manufacturing of somewhat larger rectangular building blocks, in particular rectangular building blocks having -11 - heights of more than 50 cm and/or widths of more than 30 cm and/or thicknesses of more than 15 cm. Other dimensions and shapes are however also possible.

Thus the invention provides an installation with which accurately dimensioned and strong building blocks can be manufactured in a cost-efficient manner and at high 5 production speed. In particular the installation has proven very suitable to be used for the handling of sand-limestone mixture for the manufacturing of calcium silicate building blocks. The material properties thereof need special careful treatment during the filling process in order to be able to assure a fast, reliable and evenly distributed filling of mould cavities, including their most critical portions along the corners and edges close to their short sides.

Claims (15)

A building block production installation, comprising: - a loading trough which is adapted to be filled with a quantity of hard-hair building block mixture, in particular sand-lime brick mixture, which loading trough has an outlet opening on its underside; 5. a carrier on which the loading trough is mounted, which carrier and trough are movable together in a direction of movement to and from a dispensing position in which the outlet opening of the loading trough is positioned above at least one filling opening of an assembly of one or more mold cavities that are limited inside a manufacturing mold; Multiple rotatable stirrers positioned side by side above the outlet opening in the loading trough; and - one or more drive units for moving the carrier and / or rotating the stirrers, characterized in that rotational axes of the stirrers extend in a direction that is substantially parallel to the direction of movement of the carrier. 2. Installation as claimed in claim 1, further comprising: - a manufacturing mold with the assembly of one or more mold cavities with filling openings at their upper side, wherein the filling openings have elongated, in particular rectangular, cross-sectional shapes with center lines, the center lines of the filling openings being extend in a direction that is substantially perpendicular to the rotational axes of the stirrers. 25 3. Installation as claimed in claim 1 or 2, wherein different drive units are provided for each of the stirring members such that they are drivable independently of each other with different directions of rotation and / or speeds. Installation according to claim 3, wherein a control unit is provided for controlling the direction of rotation and / or speed of each of the different stirrers. 5. Installation as claimed in any of the foregoing claims, wherein at least three, in particular at least four, stirrers are provided next to each other. 35 - 13- An installation according to any one of the preceding claims, wherein each of the stirrers comprises an elongate shaft with outwardly projecting teeth. Installation according to claim 6, wherein the outwardly projecting teeth form part of star-shaped plate segments. 8. Installation as claimed in claim 6 or 7, wherein the outwardly projecting teeth of adjacent stirring members engage each other. Installation as claimed in any of the claims 6-8, wherein the outwardly projecting teeth of adjacent stirring members are offset in the horizontal direction relative to each other. 10. Installation as claimed in any of the foregoing claims, further comprising: - a feed means for feeding hard-hair building block mixture, in particular sand-lime brick mixture. 11. Installation as claimed in any of the foregoing claims, further comprising: - a pressing member for pressing the building block mixture within the mold cavities to compressed uncured building blocks. Installation according to one of the preceding claims, further comprising: - expressing means for expressing the uncured building blocks from their mold cavities. Installation according to one of the preceding claims, further comprising: - transport means for transporting the uncured building blocks to an autoclave for curing. 14. Use of the installation according to one of the preceding claims, wherein sand-lime brick mixture is used for the production of sand-lime brick building blocks. Method for operating the installation according to one of the preceding claims, comprising the steps of: 35. filling the loading trough with an amount of curable building block mixture, in particular a sand-lime brick mixture; - moving the carrier and trough together in a direction of movement to and from the delivery position while the mixture flows out through the outlet opening of the loading trough into the at least one filling opening of the assembly of one or more mold cavities; and - rotating the plurality of stirrers above the outlet opening within the loading trough during at least part of the movement of the carrier and trough in the direction of movement; 5 wherein the stirrers are driven separately in different rotational directions and / or with different rotational speeds during at least part of the movement of the carrier and trough in the direction of movement.