CH649225A5 - METHOD AND DEVICE FOR ADJUSTING A QUANTITY OF LIQUID SEPARATED ON PARTICLES, AND USE OF THE METHOD. - Google Patents

Description

The invention relates to a method and an apparatus for adjusting the amount of liquid deposited on the surfaces of particles. The process is particularly suitable for the production of mortar or concrete using the treated particles, which in this case are grains of sand.

For the production of cement mortar or hydraulic limestone mortar, which is used in the construction of buildings or structures, fine aggregates, including river sand or mountain sand or artificial fine particles, are widely used. When extracting or crushing various ores, such as those used in the metallurgy or ceramic industry, or coal, fine particles or dust are formed. Depending on the area of application, it is also necessary to grind the ores or coal into grains of a predetermined size. When these substances are pulverized or refined, or used for chemical reactions, granules in the form of a slurry or the like are often formed. As is known, these fine grains contain a substantial amount of water that adheres to their surface. This applies not only to river sand or mountain sand, but also to coal. Recently, these substances have been dug, especially with the use of water jets, so that the amount of separated water is very large. Water is even used to collect converter slag, which is inherently water-free in its manufacture. If these materials are stored outdoors, they will also get wet through rain or snow. Such wet particles cannot be used directly. If, for example, these materials are coked, sintered or subjected to a converter process, it is also necessary, if they are placed directly in an oven, to dry them before they are actually used. This requires separate thermal energy, i.e. fuel.

If a fine aggregate from river or mountain sand is used for the production of mortar or cement, the amount of water or surface water separated is an important factor that influences the quality of the product. The composition and particle size of the sand also influence the quality of the product. However, as long as sand is used from the same extraction site, it usually has the same composition and particle size. It is not common to mix sand from other places of origin. If the sand contains particles of different sizes, it is easy to classify them according to fine, medium and coarse particles with a sieve. A small difference in particle size does not make a big difference in the quality of the product. However, the amount of surface water changes greatly depending on the origin, the type of extraction, the extraction and the settlement of the sand. In addition, the specific surface area of the fine sand particles is large, so that the relative amount of water separated is large. In addition, sand contains water in the spaces between the sand particles, which change over time depending on the weather. 60 If sand is stored on the ground from the same place of origin, the water content changes from top to bottom as well as in the morning and at noon.

When cement mortar or concrete is made using a fine aggregate, the ratio of water to cement is W / C, the ratio of cement to sand, C / S, and the ratio of cement and / or sand to coarse Aggregate, S / G or C / G, have a major impact on the strength of the result

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the product, its fluidity, its malleability and its processability.

Thus, if an excessive amount of water is included, segregation and formation of greens are inevitable, thereby reducing the mechanical strength of the product. On the other hand, the lack of water affects the formability and the pouring property, so that even when vibration or pressure is applied at the time of molding or pouring, it is difficult to obtain a dense structure, which also reduces the mechanical ability. Regardless of the fact that the choice of a suitable ratio W / C etc. is essential, since the amount of water separated changes greatly and because it is difficult to measure the amount of surface water in a simple and accurate manner, ideal conditions are problematic of W / C and S / C etc. to realize. Although it has already been proposed to dry the fine aggregate completely or measure its weight in water, these methods are not suitable for on-the-spot determinations when large amounts of sand are used. Above all, the first method requires a large amount of heat and time, while the second method requires the water to completely penetrate the sand to expel air - the Japanese industry standard requires that the sand be immersed in water for 24 hours - as well as a method conditionally to drain the water contained in the sand.

The object on which the invention is based is therefore to create a method and a device for quickly and precisely adjusting the amount of water which is deposited on a fine granular aggregate. By using a fine aggregate whose amount of surface water is set to a desired value, e.g. a cement mortar or concrete can be made with improved quality.

According to the invention, this object is achieved by a method according to claim 1.

The method according to the invention is carried out according to the invention with a device according to claim 13.

The impact force can be brought about by a centrifugal force which is generated by a rotating disk, by a conveyor rotating at high speed or by compressed gas.

The invention is particularly suitable for adjusting the amount of water in sand particles which are used for the production of cement mortar or a fresh concrete mass. The amount of water that remains on the surface of the sand particles is used to determine the amount of water that is subsequently to be added to the mixture of sand, gravel and cement.

The amount of water on the surface of sand particles can thus be reduced by applying an impact force, for example a centrifugal force generated by a rotating disc. The sand particles, the amount of water of which is adjusted in this way, are particularly suitable for producing a green or fresh concrete mass or cement mortar, whereby they are mixed with water, gravel and cement. This cement mortar or cement mass has a low degree of segregation and formation of grit or abrasion. The products made from it have excellent mechanical strength.

If excess surface water is removed by heat or wind energy, it is not only difficult to precisely adjust the amount of water deposited on the fine aggregate, but also a large amount of heat and a lot of time are required. The amount of water can now be adjusted by applying an impact force to the fine aggregate. With this measure, the amount of water that can be effectively removed changes depending on the amount of water originally present. For this reason, the impact force that acts on the aggregate must be determined depending on the amount of water originally present. The impact force can be achieved by impact. It is also possible to spray the particles of a coarse aggregate by applying velocity energy from a rotational force or centrifugal force. The particles so sprayed are allowed to collide with a surface, thereby removing the surface water. In this case, the surface water is transferred to the surface or body with which the particles collide, whereby the amount of water that remains on the particle surface is adjustable. The amount of the remaining liquid is thus inversely proportional to the magnitude of the impact force, causing the amount of residual water can be set to a desired value by correctly selecting the size of the impact force. Regardless of the particle size, i.e. regardless of whether the particles of an additive are fine, medium-sized or coarse, the particles usually containing a relatively small amount of liquid, for example 2 to 4%, the liquid can thus be removed in a suitable manner by using a suitable impact force will. A fine aggregate, the amount of water separated changes in a relatively small range of, for example, 2.5 to 6%, is particularly advantageous for determining the amount of water and cement to be added later. If the amount of water deposited on the fine aggregate particles is reduced or adjusted to a predetermined value, it is possible to easily obtain desired ratios of W / C, C / S and G / S, thereby ensuring uniform quality of the resulting product is guaranteed.

From the standpoint of installation costs and operating energy, it is advantageous to have the particles of fine aggregate collide against a stationary surface using a rotating disc. In this case, the particles are supplied to the central portion of the disk so that they are caused to fly away by the centrifugal force. When sand is used, it often contains mud or clay as a deposit on the surface of the sand particles. In extreme cases, the deposited sludge or clay layer binds the particles of the fine aggregate together when they meet, which increases the thickness of the layer. Furthermore, the deposited layer acts as a damping, whereby the impact force that acts on the particles is reduced. As a result, the amount of water separated changes even with the same impact force. In this case, it is necessary to clean the stationary surface with water or a rotating wiper by rotating the surface.

In the cold season, damp sand freezes. In this case, the sand must be thawed with steam to separate the particles. When using sea sand, the salt contained therein can be removed if the method according to claim 6 is applied.

The invention is explained in more detail, for example, with reference to the drawings. Show it:

1 schematically shows an embodiment of a device for carrying out the method according to the invention,

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2 shows a longitudinal section through the embodiment of a water separator A from FIG. 1,

3 shows a longitudinal section through a modified water separator,

4 shows a partial longitudinal section through the modified water separator from FIG. 3,

5 is a side view of the water separator with accessories,

Fig. 6 shows a longitudinal section through the upper portion of a modified. Water separators,

7 is a perspective view of the push frame of FIG. 6, FIG. 8 is a top view of the rotating disk of FIG. 6,

9 shows a cross section through the upper part of the water separator,

10 is a partially sectioned side view of another embodiment of a water separator,

11 is a perspective view of the fastening of a section of an abutting surface,

12 is a sectional view of the mutual association of the abutting surface, a cleaning water tank, a water-absorbing tank and a container,

13 partially in section devices for removing settled sand particles,

14 and 15 modified means for removing settled sand particles, which are simpler than the embodiment of Fig. 13,

16 shows in section a further embodiment of a water separator without using a rotating disk, FIGS. 17, 18A, 18B, 19 and 20 further modifications of water separators,

21 shows the result of the water removal in a diagram,

22 shows a longitudinal section of an embodiment of a mixer,

23 shows a cross section through the mixing chamber of the mixer from FIG. 22,

24 shows a cross section through a modified pressure chamber,

25 and 26 in longitudinal section the modified versions of mixers,

27 shows a further embodiment of a mixer in longitudinal section,

28 shows a cross section through the mixer of FIGS. 27, 29 and 30, the relative arrangement of the main and auxiliary mixing elements,

31 shows a longitudinal section through a modified mixing chamber,

32 is a perspective view of the modified mixing chamber of FIGS. 31 and

33 and 34 modified sectional elements in sectional views.

The arrangement shown in FIG. 1 for carrying out the method according to the invention has an impact water separator A, into which a fine aggregate is continuously fed by a conveyor or the like, and a mixer B. The mixer B operates continuously and is equipped with mechanisms C. , D and E for introducing a powdery hydraulic substance, water and additives, such as a dispersant.

Although other shock or impact water separators A can also be used according to the invention, the preferred separator shown in FIG. 2 has a filling funnel 1 and a rotating disc 2 arranged under the filling funnel 1. This rotation disc 2 has a central opening 12 for the intake of the fine aggregate from the hopper 1 and provided with a plurality of radial guide surfaces 7. The rotary disc 2 is carried by a rotatable sleeve 13, which is held by a stationary sleeve 14 via bearing 3. The sleeve 13 is rotated by an electric motor 4 via discs 5 and 15 and a belt which runs around these 5 discs. The rotary disc 2 is enclosed by a ring 6, a suitable distance remaining between them. The ring 16 is removably seated on the inside of a lower, frustoconical hollow housing 10. In the lower section of the lower housing 10, a funnel-shaped receptacle sits, forming a suitable gap therebetween. Adjacent to the discharge opening 18 at the lower end of the receptacle 8 is a conveyor 11 arranged for the reception of the fine aggregate, which falls down after the impact on the ring 6. The ring 15 6 is slightly inclined. If desired, its upper edge can be curved inwards to prevent the sand particles from spraying upwards. With this construction, guide surfaces 7 can be omitted. By increasing the angle of inclination of the ring, the collecting effect 20 of the sand particles can be improved by the receptacle 8. At the lower end of the hopper 1, a water spray pipe 16 is provided. If desired, a screw or ribbon stirrer can be provided at the lower end of the hopper to apply a suitable amount of water uniformly to the sand particles. The water separated by collision on the ring falls down to the bottom of the lower case 10 as shown by the broken arrows.

The modified water separator A 30 shown in Fig. 3 has the same arrangement of the hopper 1, the rotating disc 2, the motor 4 and the sleeve 13. The ring or the thrust plate 6 against which the sand particles by centrifugal force, as by the rotating disc 2 is generated, thrown, is arranged between separate upper portions of a bell-shaped housing 10 'and reinforced by an outer ring 18a which is fastened to the ring by screws 19. This structure enables the ring 6 to be exchanged easily. The lower end 20 is bulged outwards in order to be able to receive the upper end 40 of a container 9 which is carried by a frame 22. A narrow gap is formed between the upper end of the container 9 and the bulged end 20 for the passage of the separated water, while the dewatered sand particles fall down into the container.

As in FIG. 2, in the embodiment of FIG. 3, although not shown, a conveyor is placed under the container to transport the sand particles to the mixer B of FIG. 1.

The housing 10 'of the water separator shown in FIG. 3 can, as shown in FIG. 4, be varied and can be provided with various additional devices, which is shown in FIG. 5. 4, a plurality of telescopic ring parts 9a and 9b, which are connected by connecting parts 55 31 to the upper edge 9c of the container 9, are arranged in the ring 6. The upper ends of the respective ring elements 9a, 9b and 9c are tapered so that they form a passage for the air and water together with the inner surface of the housing 10 '. These upper ends, which are designed as a 60 knife edge, continue to act in such a way that they deflect the sand particles, which move along the inner surface of the housing 10 ′, toward the inside of the container 9.

An annular 65 rotating disk 2a can be fastened to the rotating disk 2, which is inclined approximately downwards, which is shown in dash-dot lines in order to direct the sand particles to the underside. With this construction, the sand particles are against the lower section

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of the ring 6, however, a centrifugal force is applied by the inclined additional ring disk 2a, which is sufficient to separate the sand particles, so that the guide surfaces 7 can be omitted. In this case, the distances between the ring elements 9a, 9b and 9c and the housing 10 'can be made smaller than that of FIG. 4.

When the water separator of Fig. 4 operates at optimal operating conditions, the material that flows down the inner surface of the housing is essentially water and sludge, which is removed.

However, optimal operating conditions cannot always be set, depending on the properties of the sand particles. In this case, the substance falling to the outside of the container 9 through a gap between the lower inner surface of the housing 10 'and the knife-edge-shaped sections 9c is separated into water, mud and sand particles, which are returned to the hopper 1 by a conveyor or the like can be returned. The water component separated by the water separator can be used to produce concrete mortar in a subsequent step.

Fig. 5 shows an embodiment of a practical arrangement taking into account the above factors. An elongated, inclined drain 34 is arranged under the lower end of the housing 10 '. The container 9 is shaped like a funnel, the lower end 19b of which faces a conveyor 11 such that a certain amount of sand particles, the amount of water of which is set, accumulates in the lower part of the container 9 and essentially seals it. The lower end of the outlet 34 opens into a funnel-shaped water receiver 36,

which is arranged in a drainage water tank 35 for collecting the separated water in the water receiver 36. An inclined endless conveyor 33 with receiving pieces 33a is provided for the discharge of solid components which have accumulated in the lower section of the receiver 36. For the discharge of the water into the water tank 35 by a pump, not shown, a discharge pipe 32 with a suction opening 23 is arranged so that the water can be used for the production of cement mortar or concrete. A water supply pipe 25 with a water level detector 24 is assigned to the water tank 35, so that the water level in the tank 35 can always be kept at a constant level. If desired, the water supply line 25 can open into the drain 34 to clean it, or in the vicinity of the outlet end of a conveyor 30 which serves to introduce sand particles into the hopper 1 in order to add water to the sand particles.

Although the purpose of the water separator according to the invention is to adjust the amount of water deposited on the sand particles, i.e. the surface water, when the sand is essentially dry, i.e. contains only a small amount of water, it is necessary to add water to the sand contained in the hopper 1. In some cases, the sand contains mud or clay, which leads to sticking to the surface of the ring 6, especially when the water content of the sand is low, so the addition of water is recommended. The added water removes the mud or clay that has settled on the ring.

If the tendency to separate mud or clay on the inner surface of the ring 6 is large, a scraper 28 is attached to the lower end of a shaft 27 and is rotated by a motor 4a at a relatively low speed, for example less than 10 min-1 . The layer of mud on the ring 6 acts as a damper, so that the adjustment of the amount of water is impaired by using an impact force. In addition, the adhesive layer of the separated sludge holds sand particles. If the adhesive mud layer is removed by the scratch 28, the efficiency in adjusting the amount of water can be improved.

A screw 29 is attached to the vertical shaft 27 in order to constantly feed the sand to the rotating disk 2 from the hopper 1. Changes in the amount of sand supplied to the rotating disc 2 prevent the water content from being adjusted uniformly.

Details of the modified water separator are shown in Figs. 6 to 9. A vertical feed pipe 51a connected to the bottom of a hopper 51 is directed toward the central portion of a rotating disk 52. At the lower end of the feed pipe 51a, discharge openings 51b are formed on opposite sides. As shown in Fig. 8, the rotating disk 52 is provided with a plurality of radial guide surfaces 57 to distribute and throw away the sand particles which are supplied through the discharge openings 51b. As shown in FIGS. 7 and 9, the rotating disk 52 is seated in a rectangular push frame 60 in the form of an inverted plate in such a way that the sand particles thrown away hit the inner surface 60a of the push frame 60. The lower end of this frame encloses the upper end of a container 59 with gaps 59a therebetween. Water receiving troughs 58 are provided near the lower ends of the shorter sides of the container to receive the water separated by the gaps 59a. A sleeve 54 for holding the rotating disk 52 is rotatably held by bearings 53 by a holding cylinder 56 at the upper center of the push frame 60. At the upper end of the sleeve 54 there is a disk 55 for rotating the rotating disk at a predetermined speed by means of an electric motor, not shown.

The modified embodiment shown in FIGS. 6 to 9 operates as follows:

The sand particles fed from the hopper 51 are discharged onto the rotating disc 52 in the direction indicated, i.e. around the center of the longer sides of the bumper frame 60 in the embodiment of FIG. 9. The sand particles thrown off the rotating disc 52 are mainly directed towards the shorter sides of the bumper frame 60. The sand particles thrown onto the longer sides are guided to the shorter sides by an angle between the projection or the direction of the spin and the longer sides. In other words, essentially all parts of the thrown sand particles collide with the shorter sides, excess water being removed as a result of the impact force. The sand particles with the set amount of water are then collected in the container. The separated water flows down along the inner surface 60a of the push frame 60 and is received in the grooves 58. Mud or clay present in the original sand is also collected in channels 58. With this modification, essentially all of the thrown sand particles collide with the shorter sides, whereby the efficiency of the water quantity adjustment can be improved.

10 to 15, a further modification of the water separator and various modified parts are shown. The butt frame 60b of FIGS. 10 to 12 has the shape of a truncated cone and is constructed in such a way that its butting surfaces can be exchanged. The sand particles from a hopper 51 are caused to collide with the inner surface of the bumper frame, causing over 5

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shot water is removed. Since the sand particles have an abrasive effect, the inner surface of the push frame 60b wears out quickly. Therefore, a butt plate 68 is divided into a plurality of sections. Each section is held to the bumper frame by a gasket 68b by a fastener as shown in Figs. 10 and 11. To replace a section, it is inclined by means of a handle 68a and then pulled out of the push frame 60b through an opening 60c. A section of the push frame 60b with an annular water tank 62 is provided around the lower casing 60d. Cleaning water, which is higher than the upper edge of the jacket 60d, is admitted into the water tank 62 via an inlet opening 62a up to a mirror, namely by the height h. The purpose of the cleaning water is to prevent the sludge contained in the water from stagnating. The water flows through an outlet opening 62b into a water receiving channel 58. Furthermore, the water flows along the inner surface of the jacket 60d to the water-receiving groove 58.

The sand particles tend to stick to the inside surface of the container 59. To prevent this tendency, a vibrator 61 is installed in the container 59. The sand particles in particular adhere to the upper portion of the container so that means for removing the deposited sand particles are provided for the upper portion as shown in Figs. 13, 14 and 15.

In an example shown in FIG. 13, an air bag 67 is arranged between the side wall 59a of the container 59 and a hard rubber ring 66. By periodically changing the air pressure in the air bag 67, the sand particles that are deposited on the inner surface of the hard rubber ring 66 can be easily removed. In the embodiment of FIG. 14, only the hard rubber ring 66 is attached to the upper edge of the container 59. Even with this simple construction, the hard rubber ring 66 can be made to vibrate by the sand particles thrown onto it, as a result of which the deposited sand particles peel off. In the embodiment of FIG. 15, a hard rubber ring 66a is attached to the side wall 59a of the container 59 with a suitable air gap 65 therebetween. With this construction shown in Fig. 15, the hard rubber ring 66a can vibrate more freely and thereby remove the deposited sand particles more effectively.

In the water separator described above, since the sludge deposited on the jacket 60 and the sand particles deposited on the upper portion of the tank increase in volume with time, these separated materials prevent the water or sand particles from flowing smoothly. The use of devices for removing the deposited substances is therefore advantageous. If a rotating disc with baffles is used, an air flow is generated along the wall surfaces, which acts more or less to prevent settling. However, when sand particles settle, they prevent a smooth flow of air so that the deposits grow quickly.

16 shows a further exemplary embodiment of a water separator which removes excess water by means of an impact force without utilizing the centrifugal force which is generated by the rotating disk. In this modification, a fine aggregate, for example sand, is introduced into a hopper 1 by means of a conveyor 71 and then guided to a horizontal rotor 77 with a plurality of radial guide surfaces 79 by means of a metering device 76, which feeds sand in succession with a predetermined amount. The rotor 77 is driven by an electric motor 4, so that a certain impact force is exerted on the sand particles received by the rotor. First to third funnels 84, 85 and 86 are arranged on the front of the rotor 77 to receive the sand particles which are thrown forward by the rotor 77. Each funnel is provided with a dispensing flap 83 for dispensing the sand particles collected in it.

The first funnel 84 is used to take up water and sludge deposited on the sand particles, while the second and third funnels 85 and 86 take up sand particles whose surface water is adjusted. The funnel 86 collects coarse sand particles. Overall, the sand particles kicked by the rotor are thrown over different distances, depending on the mass of the sand particles. The water content remains on the guide surfaces and is collected on the top of the surfaces 79 by centrifugal force and then added to the funnel 84 in the form of drops ab-20. A cover 200 covers the funnels 84,

85 and 86, which are divided by adjustable partition plates 81.

In the water separator according to Fig. 16, excess water is removed by an impact force, while the sand particles are classified according to their particle size. Since the amount of water remaining on the treated sand particles differs depending on the particle size, this modified water separator is particularly suitable for a fine aggregate with particles of different sizes, 30 since the sand particles are classified according to their size. Accordingly, they have in each of the funnels 85 and

86 sand particles collected are essentially the same particle size. The amount of water remaining on the sand particles is also essentially constant.

35 Further embodiments of water separators are shown in FIGS. 17 and 18. In Fig. 17 the fine aggregate, i.e. the sand is dropped between a pair of parallel spaced hard rubber rotors 75 rotating at a speed greater than 40 the rate of fall of the sand. The sand is then discharged downward and falls onto an inclined push plate 18 which is fixed by a holder 78e.

The water separated on the surface of the sand particles is then separated. The sand particles, as shown by the solid arrows 45, are deflected to the left and discharged through a discharge opening 73. The separated water and the sludge are collected in a trough 74. Cleaning water is supplied from a storage tank 62 via an inlet opening 62a and an outlet opening 62b is removed in the same way as in the embodiment of FIG. 12 in order to wash away dirt or sludge, that has accumulated on the back of the jacket 62d. The sand particles can be thrown in the horizontal direction or somewhat downwards as in FIGS. 6 to 15 55 and 17. Two or more pairs of rotors 75 may be placed side by side to increase the amount of sand to be treated.

In a further modification, shown in Fig. 18A, the sand particles falling from the hopper are flung at 60 at high speed against an inclined push plate 78 which is fixed by a holder 18e by means of a pair of conveyors 72 which run at high speed. A jacket 62d is supplied with cleaning water at a location lower than the shock 65 plate 78 to prevent sludge from adhering to the inside surface of the jacket. High speed belt conveyors 72 apply high speed energy to the spun sand particles regardless of their size

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brought into effect. Where the belt conveyors 72 are not intended to run at high speed, the upper belt conveyor 72 is replaced by a rotating element 80 which sits at the discharge end of the lower belt conveyor so that a required speed energy is applied. When the belt conveyors are running at high speed, the sand particles tend to jump or spray, reducing the efficiency of impressing the speed energy or impulse.

With the construction shown in Fig. 18B, it is possible to effectively remove water without dropping sand particles from the conveyor. If the sand particles are not to be flung in the horizontal direction, the sand particles can be flung downward as in FIG. 17.

In the modification shown in FIG. 19, the sand particles are fed from the hopper 1 to a high pressure air nozzle 98 via a metering device 97, whereby the particles are ejected against a thrust plate 78 by the speed energy of the high pressure air. This removes excess surface water. As with the previous embodiments, the inner surface of the jacket is cleaned with cleaning water.

Since, in the above-described embodiments, essentially all of the sand particles on which the high-speed energy acts are brought into contact with a collision plate, the collision plate wears out quickly, so that it is necessary to replace it frequently. The modification of Fig. 20 is built to avoid this problem. A pair of spaced belt conveyors 235 are used to apply high speed energy to the sand particles so that they are flung away by the belt conveyors and collide with each other in the space between the conveyors so that the water removed from the sand particles in this space is sprayed. A motor-driven blower 241 is used to draw off the air that carries the sprayed water to the outside via a line 242, which may have a mist separator (not shown). Although not all the sand particles thrown away collide with one another in this construction, only a small proportion of the sand particles thrown hit an impact plate 212 in the form of an inverted funnel, so that its wear remains small.

In the embodiment shown in FIG. 20, the impact force is different for the respective sand particles, so that the amount of water remaining on the sand particles is not always constant. To rule this out, a butt plate 234 shown in dash-dot lines can be arranged between the belt conveyors 235. When sand particles containing mud are thrown away, the push plate 234 is taken out and cleaned through a window, not shown. The butt plate 234 can be a thick casting.

In each of the above-described embodiments, a substantially uniform impact force is applied to the fine aggregate to remove the excess water. As long as the impact force is greater than the adhesive force of the water on the particles of the fine aggregate, it is possible to remove excess water. The removed water flows down along the impact plate, while the particles of the fine aggregate can fall down or move outwards.

The result of the water separation brought about by the water separator according to the invention is shown in FIG. 21. Regardless of the difference in the amount of surface water, which changes depending on the particle size, as long as the amount of surface water has a predetermined limit before treatment

21, it can be seen from the curves of Fig. 21 that a substantially constant amount of water remains on the sand particles after the treatment. Even if the amount of original water is less than the predetermined limit, an amount of water that is proportional to the initial amount of water can be removed. When the impulse force is increased by increasing the speed of the rotating disc, the amount of water remaining after the treatment decreases and vice versa, but the shape of the resulting curves is similar to that shown in FIG. 21. For this reason, in order to make the amount of water remaining after the treatment uniform, an amount of water is added to the fine aggregate to adjust the initial amount of water to be higher than 15%, for example. "FM" in Fig. 21 is a measure of the grain size.

In the embodiment shown in FIG. 1, water is added to the mixer B in two stages, which is mixed with the fine additives that have been treated by the water removal device A.

In the first stage, water is added to the treated fine aggregate with a water sprayer. The additive is mixed intimately to apply a uniform amount of water to the respective particles. Then, a powder of a hydraulic substance such as cement is added by an adding device C and mixed with the fine aggregate, whereby cement shells are formed around the particles of the fine aggregate. An additional amount of water is added by means of an additional water device D2. The mixture is then kneaded. The shells thus formed are stable enough to withstand the subsequent addition of water and kneading. A component molded with this mixture has great mechanical strength. After the hydraulic substance has been enclosed, the mixture can be transported to a remote station.

It is not always necessary to add water in two stages and the hydraulic substances between the addition of the water. The water can also be added all at once. The fine aggregate, the amount of surface water of which is set to a predetermined value by the impact force, determines the amount of water to be added thereafter to form a compulsively mixed or kneaded mass. This allows the ratio of water to cement W / C, the ratio of sand to cement S / C and other factors of the mixture to be determined in a reasonable manner in order to achieve a uniform and increased mechanical strength of the products. Although coarse aggregate can be added at any stage, it is advantageous to add it immediately before adding the primary water.

A preferred example of a mixer is shown in FIG. 22. This mixer has a mixing chamber 110 with a screw mechanism 104. As shown in FIG. 23, the mixing chamber 110 is U-shaped in cross section and lined with an elastic cover 105. On the outside of the elastic cover 105, chambers 106 are provided for applying a pressure, as a result of which the cover 105 is pressed inwards. Fine aggregates, the surface water of which is adjusted, and coarse aggregate are introduced into the mixing chamber 110 at the left end via filling funnels 101 and 103 and a belt conveyor 111. Then, a predetermined amount of water is added from a water tank 114 through a pipe 115 and a valve 115v. In an intermediate section of the mixing chamber 110, the water tank 114 passes through a branch pipe 116 with a valve 116v

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intestinal water supplied. One or more additives, such as dispersants, retardants, rapid curing agents, etc., are fed from a tank 117 via a pipe 118 with a valve 118v to the branch pipe 116. If the plurality of additives are not to be introduced at the same time, a plurality of independent tanks can be provided, each of which contains an additive. At the rear or right end there is an outlet opening 109 for the delivery of the kneaded mass to a container 120. The mass in the container is sent to a processing station by means of a tank truck,

a pipe, a conveyor or the like.

The pressure applying chamber 106 is sealed. It is supplied with compressed air or water. If a pulsating pressure fluid is present, the mass adhering to the elastic film 105 can be easily removed. The pressure-applying chambers 106 contain elastic tubes 108. The tubes 108 can, however, also be replaced by sponge rubber or by a hair mass, which is understood to mean a mixture of human or animal hair, which is connected by latex or a synthetic resin binder, and an essential one Have elasticity. Although the pressure applying chamber 106 can be provided along the entire bottom length of the mixing chamber 110, it is advantageous to provide a plurality of spaced pressure applying chambers 106, as shown in FIG. 22. This structure prevents the elastic film from bulging excessively into the mixing chamber and impairing the functioning of the screw mechanism.

If the mixer shown in FIG. 22 is used for the production of masses, such as mortar or concrete, the mixing chamber 110 is supplied with cement powder from a cement tank 102 via a metering device 112. A first stage I results from the mode of operation between the sand hopper 101 and the cement tank 102. The second stage II results from the mode of operation between the cement tank 102 and the secondary water supply pipe 116. The third stage III results from the mode of operation between the pipe 116 and the Dispensing opening 109. In order to produce mortar or cement, part of the water required for producing the finished mass is added to the mixture of sand and gravel via pipe 115 in the first stage I. The water content of the mixture is made uniform by the screw mechanism 104. A measured amount of cement is then added to the mixture to form stable cement shells around the respective sand particles in the second stage II.

For the production of cement mortar in the third stage III, the secondary water is added via the pipe 116 together with one or more desired additives. In the connection shown in FIG. 22, the additive is first mixed with a large amount of secondary water in the pipe 116, so that an additive with a high viscosity can also be mixed uniformly.

Instead of using a single elastic tube 108 as shown in FIG. 23, a plurality of adjacent tubes 108 may be used as shown in FIG. 24. With this type of construction, it is not necessary to design the pressure-generating chamber 106 in such a way that it is sufficiently airtight. Furthermore, the tubes 108, which must be airtight,

not be damaged by friction that can arise from the worm mechanism 104. When water is introduced into the pipes 108, their internal pressure can be easily adjusted simply by changing the level of a water tank. For example, the water tank can be arranged at a location 1.5 to 2 m higher than the pipes 108. It has been shown that this mirror in the water tank is sufficient to produce a satisfactory cement mortar or concrete.

As shown in FIG. 23, additional pressure applying chambers 126 may be provided over the worm mechanism 104 which contain an elastic tube. The elastic tubes 128 not only contribute to the action of the elastic tube 108 at the bottom of the mixing chamber, but also reinforce the U-shaped elastic film 105, particularly when it is more or less aged or stretched, thereby maintaining a desired sealing relationship with the screw mechanism 104 becomes.

The discharge opening 109 may be formed on one side of the mixing chamber 110, as shown in FIG. 22, since this construction can contain the mass over the entire length of the mixing chamber, so that even if the mass has a markedly high fluidity , the entire length of the mixing chamber can be used effectively.

25 and 26 show modified mixers. 22, the mixing chamber 110 consists of a single, one-piece part, the mixing chamber 110 of FIGS. 25 and 26 is produced from a multiplicity of sections. In the embodiment of FIG. 25, the mixing chamber 110 has a plurality of sections 110a, 110b and 110c which are connected in cascade and which are arranged at different heights. For the first section 110a, a sand tank 101, a water tank 121 and a motor M! driven first screw section 104a is provided. The sand tank 101 has a water content measuring device 122 for measuring the water content of the sand treated by a water removal device A as described above, thereby controlling the amount of water supplied to the water tank 121. The second section 11Od has a second section 104b of the screw mechanism and a filling funnel 110e for receiving the mixture of sand and water from the first section 110a and a measured amount of cement from the cement container 102. The third section 110c has a filling funnel 1 lOd for receiving the kneaded mixture from the second section 110b and for secondary water from the water tank 123 and also a discharge opening 109 at the end of the third section, which is connected to a discharge pipe 124 for conveying the mass obtained to a receiving device 120.

The section 104b of the screw mechanism is connected to a hollow tube which has a second section. The hollow tube is rotated by means of a motor M2 via a pinion and a ring gear 134 which is attached to the tube. A horizontal shaft 135, which is driven by a motor M3, extends through the third section 110c. The horizontal shaft 135 has a plurality of stirring blades 136 that are set at a predetermined angle to ensure uniform mixing.

In the modification in Fig. 26, sections 110a, 110b and 110c are arranged coaxially, thereby forming a continuous mixing chamber. Sections 104a, 104b and 104c sit on a common shaft 140 which is driven by a motor M4 which is located in the mixing chamber of Fig. 26 on the left side. The second section 110b and the third section 110c are driven by motors M2 and M3 in the opposite direction to the screw sections 104b and 104c,

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to improve the mixing efficiency. To add the secondary water at the same location as shown in FIG. 25, the shaft 140 is hollow at least in the third section to supply water from a water tank 133 through openings 133a at one end of the third section 110c.

25 and 26 is more or less complicated because the volume of the contents of the respective sections changes with constituents added to the respective sections, it is possible to build the respective sections so that they contain a content changing volume. Mixtures of different types can be used in the respective sections as shown.

Another example of a mixer that can be used is shown in FIGS. 27 and 28. The mixing chamber has a U-shaped cross section and a length which is sufficient to complete the entire mixing and kneading process. A horizontal rotatable shaft 159 extends through the mixing chamber 160 and is provided with a multiplicity of mixing elements 158, all of which are longitudinal a spiral are arranged. The angle of inclination and the pitch of the respective mixing elements change according to the mixing levels. At the left end of the first section I sand is fed by a belt conveyor 151, the water content of which is set in the manner described by means of a water removal device A. The primary water is supplied essentially at the same point via a water pipe 155. Coarse aggregate, i.e. Gravel is supplied from a gravel tank 155a at a point between the first section I and the second section II, while cement from a cement tank 155c is then added to the gravel tank 155a. The secondary water and additives are supplied at a point between the second section II and the third section III through pipes 155b and 155d, respectively. In addition to the mixing elements 158, relatively small auxiliary mixing elements 157 are arranged on the sections of the shaft 159 in the first section I and in the second section II. These additional mixing elements 157 are inclined opposite to the main mixing elements 158. If the direction of the additional mixing elements is the same as that of the main mixing elements, the angle of inclination of the additional mixing elements is set larger than that of the main mixing elements. The main and additional mixing elements are inclined and arranged along a continuous spiral line. 29, 30, 33 and 34, the main mixing elements are separated by more than 30 ° around the circumference of the rotating shaft 159 and constructed so that each main mixing element is at an angle of less than 360 ° extends. As shown in FIGS. 29 and 30, the additional mixing elements 157 have a lower height than the main mixing elements 158. In FIG. 30, additional mixing elements 157 are used to hold the main mixing elements 158.

As shown in FIGS. 33 and 34, both the main and additional mixing elements 158 and 157 are fixed to the rotating shaft 159 by means of suitable fastening devices 156.

In the constructions shown in FIGS. 27 to 37, the moving speed of the mixture toward the outlet opening 166 changes depending on the angle of inclination of the mixing elements 157 and 158 to the rotating shaft 159 in accordance with the change in the mass of the mixed composition added. If you only consider the weight, the speed of movement is minimal at the feed end, while it is maximum at the discharge end. However, in the method in which the water content of the mixture changes, this problem is not so simple. The volume changes between a case in which sand has a relatively small amount of water, for example 2 to 3%, and a case in which the sand contains much more water. If cement is enclosed in a relatively dry mixture that forms shells, its volume becomes a maximum, while if water is added to increase the fluidity of the mixture, its weight increases, but its volume decreases significantly. In the measure shown in Fig. 27, in which the primary water is added to make the surface water uniform, the inclination angle of the main mixing elements 158 is set to a normal value, while the additional mixing elements 157 are inclined in the opposite direction to increase the feed speed relatively slowly realize. In the second stage II, the angle of inclination of the main mixing elements 158 is made relatively large, as shown in FIG. 29, while the angle of inclination of the additional mixing elements 157 is made larger so as to achieve a higher feed rate, so that an increase in the mass in the Level II is possible. In stage III, the fluidity increases after the secondary water is enclosed, which further reduces the volume. For this reason, the angle of inclination of the main mixing elements 158 is set to standard in stage III in order to reduce the feed speed compared to section II. For the reason described above, the mixture can be mixed in a mixing chamber 160 with a uniform cross-section without a constant surface level, regardless of the change in bulk density. At the discharge opening 166, the surface level of the mixture decreases rapidly since the mixture is discharged, so that it is advantageous to provide an additional mixing element 157c at this section in order to make the residence time of the mixture at this section as long as possible. The mass dispensed from the opening 166 is received in a receiving device 170, but the dispensed mixture can also be conveyed through a line or a pump.

27 to 30, the change in the bulk density is taken into account by changing the angle of inclination of the mixing elements 158, in the embodiment of FIGS. 31 and 32, the change in bulk density is taken into account by the volume of the mixing chamber 160 will be changed. In particular, the height of the side walls 160d of the mixing chamber 160 is increased in section II in order to increase the volume. At this stage, in which the cement shells are formed around the sand particles and the amount of water between the sand particles is very small, even if the volume of the mixture increases, the flowability is low, so that the change in the bulk mass only increases by increasing the height of the side walls 160d can be dealt with. Even if high side walls 160d are provided, the cross-sectional content of the mixing chamber 160 is generally U-shaped, so that the transition of the mixture can be carried out effectively by the inclined mixing elements 158 and the section of the mixture which is arched upwards in section II is one effective mixing process is subjected. If the gradient of the mixing element in section II is selected in a suitable manner, effective mixing and kneading of the mixture over a relatively short length of section II is ensured.

The embodiments of FIGS. 27 to 30 are suitable for producing a large amount of cement mortar or cement paste with excellent properties.

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The invention is explained in more detail using the examples below.

example 1

In this example, the device of FIG. 2 is used, which has a rotating disk 2 with a diameter of 400 mm and is driven by a motor 4 with a speed of 100 rpm. The rotating disk 2 is supplied with fine river sand, which contains 3.98% water and has a fineness modulus FM of 1.28%, in order to bring about the collision of the sand particles with the impact plate 6. The fineness module FM is determined according to the following equation:

6

FM = S Pn / 100 n = 1 where Pn is weight percent of the aggregate that remains in a network of 0.15, 0.3, 0.6, 1.2, 2.5 or 5 mm after sieving. The quantity flow of the sand containing water to the hopper 1 is varied in a range from 50 to 160 kg / min. The water content of the sand conveyed by conveyor 11 is measured from 9.4 to 10.1%, which shows that the amount of surface water is essentially constant.

When the rotating speed of the rotating disc 2 is increased to 5000 rpm, the measurement gives a surface water amount of 0.06 to 6.38%, which shows that the amount of the surface water is significantly reduced compared to the case in which the rotating one Disc rotates at a lower speed, the change in the amount of surface water is much smaller.

Example 2

With the same device from FIG. 1, sand particles with an average size and a water content of 2.25% and a unit module FM of 2.28% are treated in the same way. In this example, however, water is added to the sand at the outlet from the hopper 1 at a rate of 4 l / min. When the rotating disc 2 is rotated at a speed of 1100 rpm, the water content of the treated sand is 4.7 to 5.3%, which shows that the amount of the surface water is reduced because the treated sand has a larger particle size. However, it has been shown that the area in which the amount of surface water changes has narrowed. In contrast, when the rotating speed of the rotating disc 2 is increased to 5000 rpm, the amount of the surface water changes in a narrow range of 4.33 to 4.85%.

Example 3

Coarse sand from a different origin than that used in Example 1 with a water content of 3.31% and a fineness modulus FM of 2.96% is treated as in Example 2. When the rotating disc 2 is rotated at a relatively low speed of 1100 rpm, the amount of surface water is 3.3 to 4.2%, while when rotating at a higher speed of 5000 rpm the amount of surface water is 3.2 to 3, Is 52%, which gives a narrower range.

Example 4

In this example, the device of FIGS. 4 and 5 is used, the rotating disc 2 having a diameter of 450 mm and being rotated by a motor 4 at a speed of 1250 rpm. Medium-sized river sand with a water content of 2.25% and a fineness modulus FM of 3.27% is allowed to collide with the butt plate 6. The water-containing sand is fed into the hopper 1 at a flow rate of 25 m3 / h. Water is sprayed onto the sand at 5 to 401 / min, while the sand is conveyed by the conveyor 30. The treated sand, which is collected in the lower section of the container, is transported by the conveyor 11. The extracted sand is checked by sampling every minute and the water content of the treated sand is measured. The measured water content is in a range from 8.79 to 8.93%. It turns out that the amount of surface water is essentially constant, i.e. is between 6.54 and 6.58%. The amount of sand extracted after treatment is 24.1 m3 / h, which is a high yield of 96.2%. The amount not recovered consists essentially of sludge.

When the speed of rotation of the rotating disc 2 is increased to 1500 rpm, the water content of the treated sand is 6.92 to 7.04%, the amount of surface water being 4.66 to 4.77%. At a higher speed of 1750 rpm, the water content of the treated sand is 5.79 to 5.88%, the amount of surface water is 3.53 to 3.62%. In any case, the amount of surface water is reduced and essentially constant. The amount of sand treated and recovered is 24.28 m3 / h at 1500 rpm and 24.52 m3 / h at 1750 rpm.

Example 5

The device used in Example 4 for treating medium-sized sea sand with a water content of 2.46%, a salt content of 0.33% and a fineness modulus FM of 2.62% is used. In this example, 30 rpm water is added to the sand as it is being transported by the conveyor.

When the rotating disc is rotated at a low speed, the water content of the treated sand is 8.56 to 8.71%, the amount of surface water is 6.40 to 6.55%. Since the sand is coarse, its surface water quantity is reduced even at the same speed of the disk. Although the treated sand still contains 0.03% salt, it can be used to produce fresh or green mortar or concrete, since cement shells or shells are formed. The amount of sand extracted is 23.8 m3 / h.

When the rotating disc 2 rotates at a speed of 1500 rpm, the water content of the treated sand is 6.76 to 6.83%, the amount of surface water is 4.30 to 4.37%, while increasing the speed of the rotating Disc at 1750 rpm, the water content of the treated sand is 5.51 to 5.58% and the amount of surface water is 3.05 to 3.12%, which shows that the change in the amount of water is also small. The salt content is 0.028% at 1500 rpm and 0.027% at 1750 rpm. The sand containing salt can thus be used to produce a concrete mass.

To remove the salt, it is necessary to use cleaning water with an amount that is at least equal to that of the sea sand, so that the removal of salt from 25 m3 of sea sand requires the use of 25 to 80 m3 of pure water. In contrast, in this example the amount of water added to the sea sand is 30 1 / min or 1.8 m3 / h.

When salt is removed by spraying water onto the sea sand, the salt is not removed uniformly. Even if the medium amount of the permanent

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Water is 0.03%, it changes between 0.002 and 0.150%, which means that a considerable amount of the washing water contains more than 0.04% of the residual salt, which is an allowable upper limit. In this example, if water is added to the sea sand during transportation by a conveyor in an amount of only 30 l / min while the water separation is effectively carried out by the pushing force, the amount of the remaining salt is only 0.007 to 0.038%.

Example 6

Fine particles of a water-pulverized slag with a fineness modulus FM of 2.53% and a water content of 2.90% are treated as in Example 4. When the water is removed from the disk 2 at a speed of 1250 rpm, the water content of the slag particles is 8.99 to 9.27% and the amount of surface water is 6.09 to 6.37%, while at a speed of 1750 rpm the Decrease the water content to 6.19 to 6.28% and the amount of surface water to 4.29 to 4.38%. The amount of sand extracted is 20.0 m3, 24.3 m3 and 24.51 m3 at speeds of 1250, 1500 and 1750 rpm.

Example 7

The device of FIGS. 6 to 9 is used. The device is used to treat coal dust with a particle size of 0.15 to 5 mm, which contains 3 to 15% surface water. The feed rate is selected in a range from 80 to 200 kg / min.

The rotating part 52 is provided with guide surfaces with a length of 250 mm between the axis and the outer end. The rotating element rotates at a speed of 1500 rpm, which removes water from the coal dust. After the treatment, the coal dust has 4.2 to 4.3% surface water, which shows a uniform removal of water. Sludge on the particles of coal dust is also effectively separated.

Example 8

In this example, the device of Figures 10, 11 and 12 is used to remove water from blast furnace slag with 20.5 to 57.5% surface water.

The rotating element 52 has a radius of 300 mm and rotates at a speed of 2000 rpm. The treated slag contains 12 to 15% surface water. The particle size of the slag is larger than 0.1 mm, which can be classified.

Example 9

The device of FIGS. 6 to 9 is used. In this example, mineral particles with a water content of 28 to 46% and a grain size of less than 3 mm are preheated to about 80 ° C. and then filled into the funnel 1.

The rotating element 52 is provided with blades that have a length of 250 mm between the axis and the ends of the blades. The rotating body rotates at a speed of 1850 rpm. The butt plate 60a is heated to about 60 ° C. After treatment, the amount of oil remaining in the mineral particles is 4.8-5.3%, slowing down substantially uniform oil removal.

In a known method for removing oil from mineral particles, the oil is removed by evaporation. For this purpose, it is necessary to heat the particles to a temperature of 500 ° C for a considerable period with stirring. In addition, it is necessary to obtain the evaporated oil by condensation, which requires an expensive device. In contrast, the device according to the invention is simple in construction and consumes little operating energy.

The following examples show the use of fine particles from which water has been removed by the inventive method using the device according to the invention.

Example 10

To produce cement mortar using a conventional method, almost completely dried medium-sized river sand, water and 956 kg of cement are used with a C / S ratio of 1: 1 and a W / C ratio of 35%. 765 kg of dispersant in the form of lignosulphonic acid are added and the mixture is kneaded. The mixture obtained has a considerable number of air bubbles and a flowability of 42 s when measured with a J funnel that has a diameter of 6.5 cm on the loading side, a height of 45 cm and a diameter on the discharge side of 1 .0 cm. The percentage of breezing after 3 hours is 6%. The product molded with this mortar has a compression strength of 37.5, 48.9 and 56.5 N / mm2 after 3, 7 and 28 days. The change coefficient after 28 days is 15.3%.

Using the device of Fig. 4, the same sand is dewatered according to Example 4. When the rotating disc is rotated at 1750 rpm, the amount of the surface water after the treatment is 3.53%. Cement and water (total water minus residual water) and a dispersant are added to the treated sand in amounts to obtain the same ratios of W / S and W / C as described above. After kneading for more than 2 minutes, a cement mortar with a flowability of 13 s, measured with the J funnel, is obtained, while the concentration percentage is 0.5% after 3 hours. Products made with this mortar have a compressive strength of 53.2, 69.8 and 79.0 N / mm2 after 3, 7 and 28 days, respectively. The coefficient of change is 4.8%.

The water content of the same medium-sized sand is reduced at a speed of 1750 rpm of the rotating disc, which results in a surface water volume of 3.53%. After uniformly including 16.47% of primary water in the sand thus treated, an amount of cement which is sufficient to achieve a ratio of C / S = 1: 1 is added and the mixture is formed to form cement shells or -Sheathers mixed that have a W / C ratio of 20% around the sand particles. After adding 15% secondary water and 0.8% dispersant, the mixture is kneaded. A cement mortar is obtained with a flowability of 19 s and a spotting percentage of zero after 3 h. The compressive strength of the products molded with this mortar is 61.9, 73.9 and 85.5 N / mm2 after 3, 7 and 28 days, respectively, and the coefficient of change is 2.2%. Compared to products manufactured by the known method, the products according to the invention have a higher compressive strength and are more stable.

Example 11

The same amount of the sand used in Example 10, but which is not dewatered by the process according to the invention, is mixed with 347 kg of cement and 3.5 kg of dispersing agent and with water. A mortar with ratios of C / S = 1: 2, C / G = 1: 3.6 and W / C = 42% is obtained. The mortar has a setting value

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from. 2.1 cm, a noticeable horror formation and air bubbles. The compressive strength of the products made with this mortar is 20.8, 28.4 and 33.4 N / mm2 after 3, 7 and 28 days. The coefficient of change is 17.4%. The same mortar is now produced, but the surface water is reduced to 3.53%. After less than 2.5 minutes after kneading, the mortar has a set value of 8.2 cm and a certain separation and formation of spills. The products molded with this mortar have a compressive strength of 27.4, 34.8 and 48.2 N / mm2 after 3, 7 and 28 days respectively and a coefficient of change of 8.2%, which increases the strength of 50% and a uniform quality.

6.47% primary water is added to the same river sand, the surface water amount of which is set to 3.53%. The same amount of sand described above is added to form cement shells, the W / C content being 20%. Gravel, 22% secondary water and 1% dispersant based on the amount of cement are then enclosed and mixed, resulting in a concrete mass with a setting value of 11.6 cm. The product molded with this concrete has a compressive strength of 30.8, 38.2 and 51.3 N / mm2 after 3, 7 and 28 days, respectively, and a coefficient of change of 5.1%, which is an increase of 50% in compressive strength and the product is uniform.

Example 12

1.5 vol .-% steel fibers are added to a concrete mass with the same approach as in Example 11. In this example, the sand is not dewatered in the manner according to the invention. The concrete mass obtained has a setting value of 1.5 cm and has a large degree of segregation and formation of greens. The bending strength of the concrete product made with this concrete mass is 5.8 N / mm2 after 28 days.

In contrast to this, the concrete mass, in which sand dewatered according to the invention is used, has a setting value of 7.4 cm immediately after the kneading and a slight separation and formation of greens. A concrete product made from this concrete mass has a bending strength of 7.5 N / mm2 after 28 days.

A concrete mass using dewatered sand particles that are formed with cement shells that have a W / C ratio of about 20% and are enclosed in the steel fibers has a setting value of 12.8 cm and has no breezing on. The concrete product made with this concrete mass has a flexural strength of 9.2 N / mm2 after 28 days.

Example 13

The same river sand as in Examples 10 to 12 is used. When dry, 350 kg of cement, 1120 kg of sand, 700 kg of coarse aggregate and 10.5 kg of quick hardening agent are mixed. The mixture obtained is conveyed by means of compressed air to a work station, where water is added in an amount that results in a W / C ratio of 50%. The concrete mass obtained is thrown against a vertical wall by a blowing nozzle. The rebound amount is about 35%. When thrown against the wall of a tunnel, the amount of dust generated is approximately 750 CPM. 28 days after spinning, the concrete has a compressive strength of 23.2 N / mm2 and a change coefficient of 14.5%.

The concrete mass with the same composition of Examples 10 to 12, but with the amount of surface water set to 3.53%, is spun on under the same conditions. It can be seen that the rebound amount is 18% and the amount of dust generated is 340 CPM. The spun-on concrete has a compressive strength of 36.3 N / mm2 after 28 days and a coefficient of change of 5.3%.

5 To form cement shells with a W / C ratio of 20%, the same sand is used, the surface water of which is set to 3.53% and a quantity of cement is mixed. Then an amount of water is added to ensure a W / C ratio of 34.2% and 0.6% of dispersant based on the cement weight, resulting in a mortar with high fluidity. The mortar is transported under pressure through a pipe. Furthermore, a dry mixture is produced with ratios of C / S = 1: 3.01 and S / A = 56%, 15 where A is a coarse aggregate. This mixture is conveyed under pressure through another pipe. The two masses are mixed at the workplace in a ratio of 1: 1.75 parts by volume with one another and with a suitable amount of a rapid hardening agent. The concrete composition suitable for 20 spin coating has a W / C ratio of 42% and contains 353 kg of cement. It is thrown against a wall. The rebound amount at the time of spin-on is 8.9%. The amount of dust generated 72 CPM. The compressive strength of the spun-on concrete after 28 days is 44.2 N / mm2, the coefficient of change is 3.2%. The compressive strength is increased by 100%. The coefficient of change is reduced by V6 compared to the conventional concrete mass.

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Example 14

In this example, the water removal device A of FIG. 16 is combined with the mixer B of FIG. 27. A 35 medium-sized river sand is treated with the water removal device A, which has 23% water and a surface water quantity of 3 to 27% and a fineness module FM of 2.1.

The rotating element 77 is provided with guide surfaces 79 with a length of 225 mm and rotates at a rotational speed of 1250 rpm. The water-containing sand is fed to the hopper 1 with a flow rate of 50 to 120 kg / min. The sand in the funnel 85 contains 6.7 to 6.9% surface water, the sand in the funnel 86 6.4 to 6.8% surface water. The amount of surface water of the 45 sand in the funnel 86 corresponds to that of the medium-sized sand.

If the speed of the rotating element is increased to 1500 rpm, the water content of the sand in the funnel 85 is 5.6 to 5.9%, that of the sand in the funnel 86 50 is 5.2 to 5.4%. If the speed is further increased to 1750 rpm, the water content in the sand in the funnel 85 is 3.9 to 4.2% and that in the funnel 86 is 4.1 to 4.3%, which results in a substantially equal water content.

Cement, water and 1% dispersant, based on 55 of the cement volume, are added to the sand treated in this way, so that C / S ratios of 1: 2 and W / C of 43% result. The amount of water added corresponds to the difference between the added water and the surface water. The kneaded mixture 60 has a flowability that can be represented by the three parameters according to DE-OS 27 03 353. The first parameter F0 is 1.54 g / cm3 (initial shear strength), the second parameter X is 0.86 gs / cm4 (relative closing coefficient) and the third parameter A F0 is 0.0034 65 g / cm4 (relative closing coefficient) . The separation and the bruising is 0.05%. The compressive strength of a product molded using the mortar thus produced is 43.8 to 45.2 on average

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at 44.7 N / mm2 and at 52.1 to 54.5, on average 53.4 N / mm2, after 7 or 28 days. Although there is little segregation and pitting, the product has a uniform strength.

In addition to the kneading process in which the entire amount of water is added at a time, another process is carried out which involves shell formation and addition of the water in two stages. The secondary water is supplied through a pipe 155 to ensure a surface water of 10%. An amount of Portland cement is then added to achieve a W / C ratio of 20%. Finally, 153 kg of secondary water and 1% dispersant, based on the cement volume, are added to obtain a cement mortar with ratios of S / C = 2 and W / C = 43%. The flowability of the mortar can be represented by the first parameter F0 = 2.63 g / cm3, the second parameter X = 1.08 gs / cm4 and the third parameter A F0 = 0.0072 g / cm4. There is no segregation and greeting. The molded product has a compressive strength of 52.1 to 54.5, on average 53.5 N / mm2, and 62.8 to 65.6, on average 64.2 N / mm2 after 7 or 28 days.

Part of the piled sand, 285 kg water, 664 kg cement, are mixed and kneaded to obtain a mortar with a flowability, the first parameter of which is F0 = 0.74 g / cm3, the second of which is X = 1.37 gs / cm4 and its third parameter A F0 = 0.014 g / cm4. The segregation and the formation of greens are 1.4%. The product molded from this mortar has a compressive strength of 26.8 to 36.7, on average 33.2 N / mm2 and 35.3 to 50rl, on average 39.7 N / mm2 after 7 or 28 days. The mechanical strength is therefore considerably lower and variable.

Example 15

Mixer A of FIGS. 6 to 9 is used for dewatering. Fine sand containing water with a surface water amount of 3 to 27%, a water absorption of 2.8% and a fineness modulus FM of 1.93 is supplied to the upper portion of the hopper 51. Water is sprayed onto the sand at a rate of 30 1 / min while the sand is being conveyed. The rotating member 52 rotates at a speed of 1500 rpm and throws the sand at a rate of 360 to 450 kg / min. The amount of water remaining on the sand parts after the dewatering treatment is 8.3 to 8.5% and shows little change. This means that even if the speed is changed more or less, it is possible to adjust the amount of surface water as desired.

Cement, gravel and water are added to the dewatered sand in such quantities that ratios of S / C = 1: 2, S / G = 38.5% and W / C = 43% result. 1.2% dispersant, based on the cement volume, is added, and then kneading is carried out. The concrete obtained has an excellent flowability and a setting value of 15.6, with only a slight segregation and formation of greens. The product molded with this concrete mass has an average compressive strength of 28.5 and 41.2 N / mm2 after 7 and 28 days and a change coefficient of 8.8%.

When the mixer shown in Fig. 27 is used, the treated sand is added to adjust its surface water content to 10% primary water. Then 1150 kg of gravel and Portland cement powder are added, resulting in a W / C ratio of 20%. Then 83 kg of secondary water and 1.2% dispersant, based on the cement volume, are added, so that a concrete mass with ratios of S / C = 2, S / A = 38.5 and W / C = 43% results has a high fluidity and a setting value of 17.2 cm. The product formed from this concrete mass has an average compressive strength of 35.1 N / mm2 after 7 days and of 46.8 N / mm2 after 28 days, the coefficient of change being only 5%.

To check this, the water content of the same sand is measured and corrected. Then 360 kg cement, 155 kg water, 720 kg sand and 1150 kg gravel are mixed in a mixer. The concrete mass produced has the same approach described above and a setting value of 12 cm. The average compressive strength of a product formed from this is 19.7 N / mm2 and 34.3 N / mm2 after 7 and 28 days, respectively. The coefficient of change is thus 15.6%. In addition, the strength is low and variable.

Example 16

The water separator shown in FIGS. 10 to 12 is used to treat a coarse river sand with 3.8 to 26% water, a water absorption of 1.7% and a coarse grain of 3.35.

The rotating member 52 is rotated at a speed of 1750 rpm to adjust the surface water to 3.2 to 3.3% of the sand supplied from the hopper 51 at a rate of 360 to 450 kg / min. After enclosing the primary water in the treated sand to adjust its surface water to 14%, Portland cement powder is added to obtain a W / C ratio of 20%. Then 290 kg of secondary water and 1.2% dispersant, based on the cement volume, are added and kneaded, whereby a mortar with ratios of S / C = 1.5 and W / C = 38% is obtained. The flowability has a first parameter F0 of 0.69 g / cm3 (quotient from the pressure at which the mortar begins to flow through a channel of length 1), a second parameter X of 0.35 gs / cm4 (quotient a pressure exerted on the mortar and the resulting flow velocity) and a third parameter A F0 of 0.0032 g / cm4 (quotient of the product, consisting of the cross-sectional area of the channel through which the mortar flows and the difference between the two times certain first parameters, divided by the amount of mortar Q) which flowed through the channel during the two times. The mortar is transported by a pump through a pipe with an inner diameter of 5 cm and at a speed of 67 m / min to a station 120 m away. At the station, one part of sand, the surface water of which has been adjusted to 3.2 to 3.3%, 0.95 parts of gravel with a size of 1 to 15 mm and cement powder are included to form cement shells in which W / C is about 18% at a point 5 m in front of an inflation nozzle. The concrete mass is then blown against the inner wall of a tunnel.

The amount of concrete mass sprayed is about 8 m3 / h, the ratio of W / C 33.4%. The amount of cement is 509 kg / m3. The rebound amount at the time of spraying is 6.5%. The amount of jam produced is 1.21 mg / m3. Concrete up to a thickness of 120 mm is satisfactorily sprayed onto the top wall of the tower ice without peeling. The average compressive strength of the inflated concrete is 32.9 and 60.3 N / mm2 after 3 and 8 days, respectively. The coefficient of change is 3.2%. The average strength is 1.4 times that of known concrete

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same approach higher while the coefficient of change is reduced to V5.

If the amount of surface water of all sand parts is not set and only a sample part is set, and if the concrete is made by mixing the sand and then spraying it on according to a known wet or dry method, the amount of dust generated during wet spraying is 6 to 10 mg / m3, while that for dry spraying is 6 to 10 mg / m3. The amount of dust of 1.21 mg / m3, as occurs using the method according to the invention, is considerably less. When using conventional concrete, the rebound amount is 20 to 30% in both wet and dry inflation. In contrast, the rebound amount is reduced to a fraction of these sizes using the method according to the invention. The response at the nozzle is significantly less than when inflating the prior art concrete. The flow rate of 3 to 4 m3 / h of the concrete according to the prior art can be doubled if a pipe with an inner diameter of 5 cm is used.

Example 17

In this example, the water separator of FIG. 10 is used to treat river sand that contains 3 to 15% surface water and has a water absorption percentage of 2.3% and a coarse grain size of 2.1. In this example, water is added to the sand at a rate of 32 l / min while the sand is being conveyed by a conveyor. The rotating member 52 is rotated at a speed of 1780 rpm. The sand is fed in at a rate of 360 to 450 kg / min. The amount of surface water remaining on the sand particles is 4.6 to 4.7%, which shows a uniform removal of water.

Primary water is then added to the treated sand so that its surface water content is 7.6%. Then 1196 kg of gravel and such an amount of Portland cement are added that the ratio of W / C is 18%. The mixture obtained is transported by truck to the work station two hours away. At the workplace, 92.4 kg of secondary water and 1.2% dispersant based on the cement volume are added to the mixture, resulting in a concrete mass with ratios of W / C = 2.34, S / A = 38.5% and W / C = 46.8%.

The concrete has a high flowability, which is illustrated by a setting value of 12.5 cm. There is no segregation and no formation of greetings. The product molded with this concrete mass has an average compressive strength of 30.3 and 42.0 N / mm2 after 7 and 28 days as well as a change coefficient of 4.3%.

On the other hand, in the case of fresh concrete of the same approach, but produced by a known method, the setting value is reduced in proportion to the time required for the transport, whereby the workability is impaired. For this reason, it is necessary to stir the fresh concrete during the concrete. In addition, after transport over a long distance, it is necessary to add more water at the work site, which reduces the mechanical strength of the product. For example, the compressive strength of the product made with such a fresh concrete after only 28 days is only 30 N / mm 2, while the coefficient of change is about 15%, which can be compared with 4.3% according to the invention. In addition, according to the invention, it is not necessary to transport the entire amount of water.

Example 18

In this example, a mixer of FIG. 22 is used, which has an inner diameter of 350 mm in the mixing chamber 110 and an overall length of 40 mm. The shaft or worm 190 rotates at a speed of 70 rpm. River sand, the surface water of which is set at 3.8 to 4.2% by the water removal device of FIGS. 4 and 5, is supplied to the mixing chamber from a hopper 101 in an amount of 232 kg / min. Gravel is added from the hopper 103 at a rate of 412 kg / min. Subsequently, water is fed through the pipe 115 in an amount of 11.25 1 / min in order to adjust the surface water of the additives to 11.6 to 12.6%. The aggregate is added with cement from a tank 102 at a rate of 115 kg / min to form cement shells, the ratio of W / C of which is set at about 24%. Secondary water and a mixture of lignin and sulphonic acid are added to the mixture via a pipe 116 in an amount of 18.6 1 / min and 1.13 1 / min, respectively, followed by continuous kneading to obtain a fresh concrete with an amount of 20 m3 / h with W / C = 42%, C / S = 1: 2 and S / G = 1: 1.78.

This fresh concrete has a setting value of 12 cm and has no segregation and no formation of greens. The product formed with the fresh concrete has a compressive strength of 25.4, 34.5 and 44.2 N / mm2 after 3, 7 and 28 days.

Example 19

The mixer of Fig. 25 is used. An artificial light fine aggregate with a density of 1.4 and a surface water content of 8% as well as another artificial light coarse aggregate with a density of 1.6, a particle size of about 15 mm and a surface water content of about 1% are produced. The fine aggregate is fed into the hopper 101 at an amount of 159 kg / min, while the coarse aggregate is filled into the hopper 101 with the same amount. Water is sprayed onto the aggregates from the container 121 at a rate of 11 l / min in order to adjust the surface water of the aggregates to 15%.

Cement powder is added to the mixture of fine and coarse aggregates from the hopper 102 in an amount of 117 kg / min, whereby cement casings are formed around the aggregates. Subsequently, water and naphthalene sulphonate are added as water dispersants from a container 123 in amounts of 31 1 / min and 6 1 / min, respectively.

The concrete obtained has an excellent flowability, which results from a setting value of 15 cm, segregation and formation of greens (breezing) cannot be determined. The composition of the fresh concrete is 350 kg cement, 480 kg sand, 162 1 water and 18 1 water reducing agent, each per m3. The ratio of W / C is 46%. The percentage of the coarse aggregate 50%. The product made with this fresh concrete has a compressive strength of 21.6 and 38.6 N / mm2 after 7 and 28 days, respectively. The product made from the concrete according to the known method has a compressive strength of 17.3 or 33.1 N / mm2 after 7 or 28 days.

Example 20

The mixer of Fig. 26 is used in this example. Sand with a particle size of less than 5 mm and a surface water content of 6% as well as gravel with a grain size of 25 mm and a surface water content of 1% are produced and placed in a hopper 101 with quantities of 260 kg / min or 348 kg / min

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filled. The container 101 is supplied with water at a rate of 8 l / min from the container 121 in order to adjust the surface water of the additives. Then cement from the hopper 102 is added to the mixture of sand and gravel at a rate of 117 kg / min to form cement jackets around the aggregates.

A mixture of water at a rate of 311 / min and lithium sulphonate as a dispersing agent at a rate of 6 l / min is fed to the mixing chamber from the funnel 133.

The fresh concrete is poured into a container 120 and has a setting value of 17 cm, a separation and

Greetings do not show up. The concrete has a high fluidity. The composition of the fresh concrete is 350 kg cement, 780 kg sand, 1043 kg gravel, 162 1 water, 18 1 dispersant, each per m3. The ratio of W / C 5 is 46%.

The product made with this fresh concrete has a compressive strength of 22.4 and 40.3 N / mm3 after 7 and 28 days, respectively. Products made from a concrete made according to known processes have a compressive strength of 18.3 and 34.8 N / mm2 after 7 and 28 days, respectively. This shows the outstanding property of the product according to the invention.

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Claims (36)

649225 2nd PATENT CLAIMS 1. A method for adjusting a quantity of liquid deposited on particles, characterized in that the particles with the liquid deposited thereon are continuously fed to an accelerator in which an impact force is exerted on the particles which is greater than the adhesive force of the liquid to the particles, whereby the separated liquid is removed. 2. The method according to claim 1, characterized in that the impact force is in the form of a change in momentum. 3. The method according to claim 2, characterized in that the change in momentum is achieved by a centrifugal force or a wind force or by both forces. 4. The method according to claim 1, characterized in that the impact force is applied to the particles by a rotating part. 5. The method according to claim 1, characterized in that the impact force is applied by a centrifugal force in a closed chamber. 6. Application of the method according to claim 1 for particles which have an impurity, characterized in that the particles are supplied with liquid before the impact force is exerted, in order to separate the impurity with the separation of the liquid by the impact force. 7. Application of the method according to claim 1 for producing a hydraulic mass, wherein the liquid is water, characterized in that after the separation of the water with the particles, a quantity of water and a hydraulic substance are mixed and the mixture is kneaded. 8. Application according to claim 7, wherein the particles are constituents of an additive, characterized in that, after the water has been separated from the particles, a part of the water which is required for the production of the hydraulic mass is added, that the hydraulic substance which is resulting mixture of additive and water is added to form envelopes of the hydraulic substance around the particles of the additive, adding the remaining part of the water required to produce the hydraulic mass and kneading the obtained mixture. 9. Use according to claim 8, characterized in that an additive is included together with the remaining part of the water. 10. Application according to claim 8, characterized in that the amount of water added is determined according to the amount of water that remains on the particles after the application of the impact force. 11. Use according to claim 8, characterized in that a coarser aggregate and optionally a fiber substance are added to the aggregate. 12. Application according to claim 8, characterized in that the additive from which the excess water has been removed and the other additives of the hydraulic mass are transported to a work station by independent means of transport and that they are then mixed and sprayed at the work station. 13. Device for performing the method according to claim 1, characterized by a liquid separation device (2, 6, 7; 52, 57, 60; 77, 79; 75, 78; 72, 78; 98, 78; 235, 240, 212) for applying the impact force to the particles so as to remove excess liquid deposited on the particles and by means (1, 51, 242) for continuously feeding the particles to the liquid separator. 14. The apparatus according to claim 13, characterized by means (16) for supplying the liquid to the particles before they are supplied to the liquid separation device. 15. The apparatus according to claim 13, characterized in that the liquid separation device is a rotating s de disc (2, 52) and a thrust plate (6, 60), which is opposite the rotating disc so that the particles are thrown against the thrust plate by the centrifugal force generated by the rotating disc. 16. The device according to claim 15, characterized in that the rotating disk (2, 52) is provided with a plurality of radial guide surfaces (7, 57) and that the particles of the rotating disk can be fed in a central section (12, 51b) . 15 17. Device according to claim 13, characterized in that the impact force is applied by a compressed gas. 18. The apparatus according to claim 13, characterized in that the impact force by a conveyor belt (72) on 2o is brought. 19. The apparatus according to claim 15, characterized by means (9a, 9b, 9c; 59a) for dividing the particles which are thrown against the impact plate (6, 60), in particles and water separated from the particles Is 2s as a result of the collision on the butt plate. 20. The apparatus according to claim 19, characterized in that the dividing means are provided on an upper edge of a container (9, 59) of the particles from which the excess water has been removed. 21. The device according to claim 15, characterized in that the impact plate (6) is removably attached to a component (10, 60) in the form of an inverted plate, whereby excess water removed from the particles as a result of the collision on the impact plate along an interior 35 surface of the component flows downwards in the form of an inverted plate. 22. The apparatus according to claim 15, characterized by a tube (13, 51a) for the continuous feeding of the particles at a central portion of the rotating disk 40 be and through means for adding liquid to the particles at the outlet end (12, 51b) of the tube. 23. The apparatus according to claim 21, characterized by a container (8, 9, 59) for the treated particles, the upper edge of which is at a distance from the lower edge of the construction 45 partly (10, 60) is arranged in the form of an inverted plate. 24. The device according to claim 15, characterized in that the rotating disc (52) is contained in a housing (60) with a rectangular cross section and 50 that the inner surfaces of the housing are inclined downwards outwards so that the particles hit them and are thrown away by the rotating disk. 25. The device according to claim 15, characterized by means (62) for supplying cleaning 55 liquid to the push plate (6). 26. The apparatus according to claim 15, characterized by a container (59) for receiving the particles thrown onto the impact plate and by means (66, 67; 66a) for removing the at the upper part of the 60 container adhering particles. 27. The device according to claim 26, characterized in that the removal devices have an elastic hose (67). 28. The apparatus according to claim 27, characterized 65 by means of inflating the elastic tube. 29. The device according to claim 13, characterized in that the liquid separation device a rotating- 3rd 649225 of the wheel (77), which rotates about a horizontal axis and is provided with a plurality of radial guide surfaces (79), comprises that the devices (71, 1) for supplying the particles supply them to a space between adjacent guide surfaces, that devices (4) for rotating the wheel at a speed sufficient to remove excess water from the fine particles to propel the particles away from the wheel substantially in a horizontal direction and a plurality of receptacles (84, 85, 86) for the particles are provided which are arranged side by side in the horizontal direction in order to classify the particles according to their size. 30. The device according to claim 13 for the production of cement mortar or a concrete mass, wherein the liquid separation device is a device (A) for removing excess water from an aggregate which is formed from the particles, characterized by a kneading mechanism (B) for kneading the mixture Water, cement and aggregate from which the excess water has been removed, thereby producing a cement mortar or concrete mass. 31. The device according to claim 30, characterized by means (Dls D2) for supplying primary water and secondary water and by means (C) for supplying cement, which are arranged between the device for supplying the primary water and the secondary water. 32. Apparatus according to claim 30, characterized in that the kneading mechanism has means (E) for adding one or more of the substances, consisting of a dispersing agent, a rapid hardening agent and a delaying agent. 33. Device according to claim 30, characterized in that the kneading mechanism has a shaft (140, 159) which is provided with a plurality of mixing elements (104, 157, 158) which are arranged along a helix. 34. Device according to claim 33, characterized in that the mixing elements (157) are divided into a plurality of sections (157a, b, c) along the shaft, the pitch of the mixing elements of the different sections varying. 35. Apparatus according to claim 33, characterized in that the shaft sits in a mixing chamber (110) which is divided into a plurality of sections (110a, b, c) along the shaft, the volumes of the sections corresponding to a mixture mass to be kneaded are trained differently. 36. Device according to claim 33, characterized in that the mixing elements (157, 158) have different sizes and are nested. 37. Device according to claim 36, characterized in that the large and small mixing elements are inclined in opposite directions. 38. Device according to claim 33, characterized in that the shaft is contained in a mixing chamber (110) and the shaft and the mixing chamber are relatively rotatable. 39. Apparatus according to claim 38, characterized in that the mixing chamber (110) has the shape of a U-shaped part which is lined with a flexible element (105), an elastic hose (108) on the outside of the lower one Section (106) of the flexible element is arranged and can be inflated by a pressure fluid.