AT504291B1 - APPENDIX FOR THE PRODUCTION OF DRY AND WET MIXTURES - Google Patents

Abstract

The invention relates to a method and a plant for the preparation of mixtures of pulverulent or granular substances. The required quantities of the raw materials for a mixed batch of a specific mixing formulation are measured by means of measuring containers, for which a raw material for a mixed batch a measuring container in rapid succession from the storage container ( 1) is filled for the raw material ago and the filled amount is measured and emptied on the discharge side. The last filling process of a measuring container with the remaining quantity of raw material missing for the appropriate total quantity takes place at a slower rate than the preceding filling operations. The raw material contained in a recipe in a predominant proportion is fed from several feed points to a mixer ( 5) loaded on a conveyor belt (3), wherein between these feed points further supply points are arranged, which are intended for the delivery of other raw materials on the conveyor belt (3).

Description

Austrian Patent Office AT 504 291 B1 2012-10-15

Description: The invention relates to a plant for the production of dry or wet mixtures of powders or granules. The plant is well suited for the production of mixtures of building materials, in particular of dry mortar mixtures. [0002] The currently most common type of construction for plants for the production of fresh concrete or dry mortar is the so-called tower construction. An example of this is shown in DE 3027069 A1. The raw materials are arranged in vertical silos arranged a few meters above the ground. In the manufacturing process, they are brought from above by a weighing device in a mixer, and mixed there. Thereafter, the finished mixture is loaded into transport vehicles, which are arranged under the mixer. The two advantages "low floor space requirement" and "material only needs to be transported downwards during manufacture". There are also several disadvantages. Due to the high center of gravity and the large weight per area, such facilities require huge and therefore expensive foundations, especially if they are erected in zones where earthquakes can not be completely ruled out. The raw material must be pumped up to the top during delivery, which is time consuming, energy consuming and can limit the production capacity of the plant. The plant can be expanded only with great difficulty to greater capacity; It is usually easier to set up multiple times. The production capacity is dramatically reduced if the plant is often to switch between different types of products to be produced. It is thus virtually impossible to produce a wider range of mortar types, which also includes various clearly defined colors. DE1564308 A shows a process for the production of concrete from cement, several sands with different particle size and water. The different sands are stored in separate silos, from which they simultaneously flow to a conveyor belt during the production process, so that they are already there in individual layers against one another, and thus a pre-mixing takes place. From the conveyor belt, the sand mixture is conveyed to a pre-vessel upstream of the mixer and weighed. From the Vorgefäß reaches the sand mixture in the mixer. The cement also passes from a silo located above the mixer through a weighing device into the mixer. The required amount of water is supplied to the mixer before or during mixing. An advantage of this device is that on the conveyor belt pre-mixing of individual components takes place, and thus the mixing process in the mixer can be somewhat shortened. It is also advantageous that the sand mixture of a mixed batch can already be provided while the mixer is still working on the previous mixing batch. The disadvantage is that the sand mixture reaches the mixer in one go, and the cement on a separate route to it. As a result, sand mixture and cement are hardly mixed at the beginning of the mixing process in the mixer, and the mixing process must take a relatively long time. The factors limiting the capacity of the plant are, above all, the capacity of the mixer, the capacity of that part of the plant which loads the largest amount of used sand into the respective silo, and the capacity of the traffic routes and stops at the plant for supply and delivery Removal of material required transport vehicles.

EP 1324865 B1 shows a process for the production of concrete in which metal fibers are embedded. Even before the individual components get into the mixer, they are passed in measured quantities together on conveyor belts and pre-soaked with water. This impregnation separates the metal fibers bonded to packages. Thus, the subsequent mixing process can be abbreviated.

In EP 0841137 A2 a system and a method for the production of mixtures, in particular dry mortar is described. For the operations measuring and bringing together the components, mixing the components, unloading the mixture, cleaning the mixing container, a container in which all components are filled, moves horizontally from one workstation to the next. The system is advantageously easy to build. Since the components of the mixture when filling in the common 1/9 Austrian Patent Office AT 504 291 B1 2012-10-15

Container to be measured on the basis of the weight of the container, the filling into the container can only be done serially and the components are not pre-mixed in the container at the beginning, so that the subsequent mixing process must be quite complex and the system is quite slow overall. Moreover, no mixed batches are not economically producible.

From this prior art, the inventor has set itself the task of providing a plant for the production of dry mortar, which - has high flexibility in the production of different mortar mixtures, - over a wide range of different has high economy probability, has high reliability and hardly maintenance interruptions.

[0009] The plant [0010] - should be cost-effective in the basic purchase, - have a high production capacity in relation to the investment costs, - if necessary be expandable by adding modules up to highest absolute production capacities, [0013] - work with high precision.

The steps required for the production of dry mortars concern: a) Delivery of the raw materials and transport of these raw materials into the corresponding storage containers, b) Sizing the required quantities of raw materials for a delivery batch of a particular recipe; either by volume determination or by weight determination, c) moving the individual components to the mixer, d) mixing the individual components to dry mortar, e) filling the dry mortar in the respectively provided transport containers and

Removal.

According to the invention it is provided that in each case a plurality of devices are provided in the system for the individual steps a, b, d, e (delivery, dimensioning, mixing, filling), which can also work simultaneously, that between the steps c and d (moving to the mixer and mixing), and d and e (mixing and filling), respectively, on which subsequent device the subsequent step can be performed. Furthermore, it is provided for step c that a plurality of different raw materials which are already correctly metered in quantity are moved by a common conveyor belt from their storage containers to the mixer, and that for this purpose they are arranged on equal lengths of the common conveyor belt.

The measurement of the components supplied at individual points by means of flow or weighing containers - further simply as "measuring container". referred to - whose capacity is small compared to the amount of material to be fed from the point concerned for a conventional mixing batch. When feeding the measuring container is filled in rapid succession from the input memory ago with relatively crude quantity accuracy, measured the amount filled, and emptied to the discharge side. At the last batch to be dispensed from the measuring container, the residual quantity still missing for the appropriate total quantity is measured as accurately as possible, and thus at least towards the end, more slowly in the measuring container and then likewise emptied onto the delivery side. Whether the measuring system is weight-based or volume-based depends on the properties of the substances to be measured.

Details, meaningful developments and effects of individual measures will be explained in more detail with reference to the drawing.

Fig. 1: shows a simple schematic diagram of the system. The material flow is symbolized by dashed arrows. Steps are indicated by letters a to e, devices by numbers.

Fig. 2: shows a view from above of a conveyor belt, via which raw materials are transported from their containers to a mixer.

The raw material typically transported by truck is filled into the storage containers 1 in step a). Typically, these storage containers are vertical silos, which are filled from above, and from which the material is removed at the lower end. The promotion in the silo can also be done for example by blowing or by means of a Gurtbecherwerkes. For insensitive raw materials that are used in large quantities, chutes are also often used as storage containers. For a raw material, which contributes to the finished product in a very large proportion, several sampling points and storage containers should be provided. This can be promoted from several trucks simultaneously in storage containers, which capacity bottlenecks are avoided in this area. Another resulting advantage is that a better pre-mixing can be achieved on the conveyor belt 3, if this material is applied from a plurality of feeding points with intermediate feed points for other raw materials to be mixed. For reasons of statics and, consequently, also for safety and cost reasons, it makes sense not to mount the storage containers too high above the ground.

In step b) raw material in a continuous flow as possible in a controlled amount removed from the storage container 1 and moved to the conveyor belt 3. Depending on the nature of the raw materials used, a volume detection or a weight detection is more useful for the quantity measuring device 2. There is a wealth of equipment available on the market that can measure and adjust a stream of bulk material. It is important that the individual feed points of raw material on the conveyor belt 3 each have such a quantity measuring device is assigned, that these devices can also work in parallel time, and thus not only accurately measured, but also accurately controlled start and end time of the flow of the discharge can be.

With the help of the measuring system described above, in which the amount of material to be entered from a point of addition in a batch is applied by multiple filling and emptying of a relatively small measuring container, only with the last such process, the appropriate residual amount is measured accurately, is compared with a conventional plant, which works with a much larger measuring vessel, measured more accurately. This is because the remaining inaccuracy is mainly determined by the unavoidable inaccuracy with which the amount of material fed into the measuring container can be controlled. With a reasonably economical design, this inaccuracy lies in a small percentage of the maximum amount that a measuring container can accommodate. The fact that compared to conventional methods, a much smaller measuring container is used, the maximum error amount is smaller, that the material flow through the measuring device takes place over a longer period of time does not bother, since several measuring devices can work simultaneously, and the material anyway on one longer area of the conveyor belt must be applied.

The advantage of more accurate measurement is of course also achieved in systems that are otherwise conventionally constructed, so not modularly controllable in the manner described further here.

In step c), the various weighed raw materials are conveyed by the conveyor belt 3 and a points station 4 to the respective associated mixer 5. It is very advantageous to control the plant so that as many as possible of the raw materials contained in a formulation are already loaded on simultaneously and jointly used length ranges of the conveyor belt 3 and thus transported. Ideally, supply points for raw material of a formulation arranged one behind the other along the conveyor belt are opened or closed at that time interval from one another, as corresponds to the delivery time on the conveyor belt between these feed points. At the individual feed points, the amount of material flowing per time is equal to the total amount of raw material required for the respective mixture from this feed point divided by the available time. As already mentioned above, it makes sense to guide the raw material predominantly present in the formulation from several feed points onto the conveyor belt and to provide such for the other individual components between these feed points.

As illustrated in Fig. 2, the mixing of the individual materials can already be significantly improved on the conveyor belt by projecting from fixed equipment parts from baffles, rakes or similar items 13 in the material flow 11 of the conveying surface of the conveyor belt 3 moving raw materials, and impose on this at least in part of its cross-sectional area a normal to the direction of movement directed movement component, of course, without material from the conveyor belt to push. For example, a first, aligned normal to the plane of the conveyor belt and the conveying direction at an acute angle baffle move the material flow 11 on the conveyor belt with respect to the conveying direction to the left, and a subsequent counter-aligned sheet back to the right. The mixing on the conveyor belt 3 can be further improved by a long sequence of such objects 13, or by actively moving these objects, such as roller-like rolling.

It may well be useful to provide several conveyor belts 3 or other conveyors such as spiral conveyors, pneumatic conveyors or Gurtbechenwerke, which can simultaneously promote the switch 4 or directly into a mixer 5. Above all, it makes sense to use different, individually adapted conveyors for very different raw material groups. For example, a common conveyor belt may be provided for the quantitatively dominating materials such as sand, lime, cement, for chemicals which are often added only in fractions of weight percent of the total amount, and for example control the drying behavior of the mortar mixture, another conveyor. For the addition of dyes, which may require a cleaning process when changing the recipe, a third conveyor can be provided. The adaptations of the individual conveyors to the respective material groups to be transported may concern, for example, the capacity, the robustness, the shielding against interactions with the environment, the flexibility with regard to path changes and the possibilities for cleaning.

It is advantageous to let the conveyor belt 3 and possibly other existing conveyor near the feed points for the individual raw materials rather close to the ground, and let rise so far towards the end of their funding that the subsequent paths of the material to the mixer and for bottling back down.

It is of course also possible to let the whole conveyor belt run horizontally at a greater height, and to promote the individual raw materials from the removal openings of the respective deposits, for example by means of a bucket elevator on the conveyor belt.

From the conveyor belt 3, the premixed raw material passes through a switch 4, depending on the switch position in one of several existing mixers 5. The switch 4 may for example be formed by a chute, which extends around a vertical, passing through the upper end of the chute Axis is pivotable. By using a plurality of mixers 5, wherein it is freely selectable, softer is applied, and wherein several mixers in the same or different Arbeitsfase can be in operation simultaneously, of course, the total capacity of the system is increased. Above all, however, it is possible to reduce breastfeeding

Stand times can be achieved, since then when individual mixers fail due to maintenance, repair or a required cleaning process, can be easily continued on other mixers. By using different types of mixers, it is possible to better understand the special features of recipes, and it enables economically viable operation over a larger range of delivery quantities per recipe. It makes sense to assign individual mixers to those groups of recipes within which no cleaning process on the mixer is required when changing between the individual recipes. For recipes after which a mixture is always required, a mixer can be better optimized for particularly simple and rapid cleaning. Of course, the use of multiple mixers also allows the short-term conversion of individual mixers to specific requirements.

The fact that the individual raw materials are already premixed when feeding on the conveyor belt 3 and possibly also by the continuous feeding simultaneously with other raw materials on the switch 4 and in a mixer 5, the actual mixing process in the mixer 5 only needs more to take a very short time.

Especially if not all the individual components are already premixed on a common conveyor belt, but some components or component mixtures are added to the mixer or to the switch, Gesamtdurchflusszeit can be saved by during the entire time in which material in the mixer flows, is already mixed.

With good premixing in the upstream conveyors, it may be sufficient to continuously mix the premixed materials in the run. That at the same time both pre-mixed batch continuously flows into a working mixer, as well as finished mixture from the mixer. Compared to mixing in individual batches, this saves some overall throughput time of the material, and a smaller, simpler and thus cheaper mixer can be used.

Consequently, the capacity of the plant part for filling and removal of finished mortar mixtures should be about the same as the capacity for delivering and storing raw material. Therefore, a plurality of loading stations 6 should be provided for the finished mortar mixture, which should be adjustable, to which loading station 6, the finished mortar mixture is to be passed from a mixer 5 from. This conveying can be done for example by means of adjustable slides, pipes, or screw conveyor. For the delivery of the mortar mixture produced is mainly the filling of mortar mixture in a tank on a truck and the filling into bags and the subsequent loading on a truck of importance.

In addition, it should be added that the traffic areas are to be designed on the system so that the individual delivery points and the individual delivery points are also easily accessible through the appropriate transport vehicles. The conveyor belt 3 should be interpreted even with an initially small-sized design in a modular extendable design and higher transport performance. Of course, it makes sense in the construction of plant parts such as chutes, silos, switches, mixers, filling stations already provide mounting options for possibly later added, further modules.

At individual parts of the system come into contact with raw material or the end product, the possibility should be provided to be able to shake it by means of vibration equipment, or to clean with air bubbles or brushes, so possibly even more strongly adhering materials without residue fall off.

In order for the system according to the invention to be able to develop its strengths, it requires central control by means of a correspondingly designed software, which appropriately controls the individual modules, and in which the individual recipes, including the work processes required for their production, are stored. With precisely planned sequences and correspondingly accurate control of the individual parts of the system, it is 5/9

Claims (6)

Austrian Patent Office AT 504 291 B1 2012-10-15 on a plant according to the invention quite possible to produce several, even different recipes simultaneously or overlapping in time on the plant. Both the required electronic control devices and the corresponding software are readily available on the market, or developable through readily available expert work, or customizable from existing modules. It will therefore not be discussed further here. The invention has hitherto been described with reference to a plant for the production of dry mortars. However, the considerations of the invention are equally applicable to plants for the production of concrete mixtures, or mixtures of powdery or granular materials such as e.g. Colors, plastics, metals, ceramics, glass and similar powder mixtures. For the production of dry mortars, a plant according to the invention is particularly advantageous over conventional plants, since high achievable capacity in combination with the good adaptability to various recipes, different color variants and greatly different Lieferlosgrößen is a particularly important strength. The considerations of the invention also apply when wet mixes or granules are produced in the system by adding liquids such as water, solvents, resins, oils, etc. in the mixer itself on the conveyor belt or on the switch. 1. A process for the preparation of mixtures of powdery or granular materials within a given for the operations receiving bulk materials delivered and transport them into the corresponding storage containers, measuring the required quantities of raw materials for a mixed batch of a specific mixing recipe, by means of measuring containers whose capacity is small is compared to the amount of material to be fed from the site concerned for a typical mixing batch, for which a batch is filled in rapid succession from the storage container and the charged amount is measured and discharged to the discharge side, moving the individual metered raw material components to one Mixer, mixing of the raw material components, - filling of the mixed goods in the respectively provided transport containers and start of the removal, suitable plant, characterized in d ass - the last required to complete a mixing batch filling a measuring container with the missing for the right total amount remaining amount of raw material from a storage container (1), at a slower speed than the previous filling operations. 2. The method according to claim 1, characterized in that a plurality of different, already properly measured in their quantity for a recipe raw materials by a common conveyor belt (3) from their storage containers (1) are moved to the mixer (5), wherein they at the same time on the same Length ranges of the common conveyor belt (3) are arranged, wherein a raw material, which is contained in a prepackaged formulation in a predominant proportion, is fed simultaneously from several Zuführungsstellen on the conveyor belt and at the same time arranged between these feed points, further feed points, other raw materials be fed to the conveyor belt. 6/9 Austrian Patent Office AT 504 291 B1 2012-10-15 3. The method according to claim 1 or 2, characterized in that several different, already properly measured in their quantity for a recipe raw materials by a common conveyor belt (3) from their storage containers (1) are moved to the mixer (5) and so by a form the conveyor belt moving material flow and that objects (13) which project from fixed system parts in the cross-sectional area of this material flow, this force a normal to the conveying direction of the conveyor belt aligned movement component. 4. Plant for the preparation of mixtures of powdered or granular materials used for the operations - Receipt of delivered bulk raw materials and their transport to the corresponding storage containers (1), - Sizing of the raw materials required for a batch of a particular compounding recipe, - individual measured raw material components on a conveyor belt (3) to a mixer (5), - mixing of the raw material components, - filling of the mixed goods in the respectively provided transport containers and start of the removal, is designed, characterized in that - on the conveyor belt (3) a plurality of feed points are arranged for the raw material contained in a recipe in a predominant proportion, wherein between these feed points further feed points are arranged, which are intended for the delivery of other raw materials on the conveyor belt. 5. Plant according to claim 4, characterized in that protrude from fixed parts of equipment objects (13) in the cross-sectional area of the on the conveyor belt (3) movable material flow. 6. Plant according to claim 4 or 5, characterized in that mutually different sized mixer (5) are used. For this 2 sheets drawings 7/9