EP0289721B1 - Method and device for continuously proportioning powdered materials using a gas under pressure - Google Patents

Method and device for continuously proportioning powdered materials using a gas under pressure Download PDF

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Publication number
EP0289721B1
EP0289721B1 EP88102609A EP88102609A EP0289721B1 EP 0289721 B1 EP0289721 B1 EP 0289721B1 EP 88102609 A EP88102609 A EP 88102609A EP 88102609 A EP88102609 A EP 88102609A EP 0289721 B1 EP0289721 B1 EP 0289721B1
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EP
European Patent Office
Prior art keywords
line
branch
synthetic silica
branch lines
silica
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EP88102609A
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German (de)
French (fr)
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EP0289721A3 (en
EP0289721A2 (en
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Thomas Deuse
Edgar Simon
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Evonik Operations GmbH
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Degussa GmbH
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28C—PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28C7/00—Controlling the operation of apparatus for producing mixtures of clay or cement with other substances; Supplying or proportioning the ingredients for mixing clay or cement with other substances; Discharging the mixture
    • B28C7/04—Supplying or proportioning the ingredients
    • B28C7/06—Supplying the solid ingredients, e.g. by means of endless conveyors or jigging conveyors
    • B28C7/062—Supplying the solid ingredients, e.g. by means of endless conveyors or jigging conveyors with a pneumatic or hydraulic conveyor

Definitions

  • the invention relates to a method and a device for the continuous dosing of powdery substances, in particular of powdery synthetic silica by means of pressurized gas.
  • the synthetic silica is fed directly to the spray nozzle via a third feed line.
  • the object of the invention is to precisely meter the addition of synthetic silica to pointed concrete and to mix it homogeneously with the shotcrete.
  • the invention relates to a process for the continuous metering of powdery substances, in particular synthetic silica, by means of pressurized gas, preferably by means of pressurized air, which is characterized in that the pressurized gas supply in a branch pipe is alternately interrupted in a pressurized gas pipe which is guided at least twice Pouring powdered substance into the branch line and then conveying the powdered substance further by means of the pressurized gas.
  • the line carrying the pressurized gas can be routed four times in branch lines.
  • the branch line can be closed off by a check cap.
  • the resulting excess pressure can be shut off via a butterfly valve and another line, e.g. into the silo that contains the powdered material.
  • the powdery substance can be conveyed from the silo into the branch line by means of known means, for example a pump.
  • the branch lines can be shut off by means of known butterfly valves.
  • Another object of the invention is a device for the continuous dosing of powdery substances, in particular synthetic silica, by means of pressurized gas, which is characterized in that a multiple, at least two-fold line, which is brought together again after the branching, in each of the branch lines
  • the direction of flow of the pressurized gas is provided with a shut-off valve and a non-return valve, the branch lines being connected via a shut-off valve to a storage silo for the pulverulent material and to a ventilation pipe.
  • the process according to the invention has the advantage that the pulverulent substance is mixed homogeneously with the concrete without loss of substance.
  • the concrete is transported from the ready-mixed concrete plant 1 to the concrete pump 3 by means of the mixing vehicle 2.
  • the concrete pump 3 conveys the concrete via the valve 4 to the spray nozzle 5. From there, concrete is applied to the wall 6.
  • the synthetic silica is conveyed from the silo 7 by means of the vehicle 8 or alternatively via the dedicated line 9 into the storage container 10 and from there into the feed device 11.
  • Compressed air is fed from the compressor into the feed device 11 via the line 12.
  • the synthetic silica is conveyed from the feed device 11 via the valve 13 into the spray nozzle 5 and mixed with the concrete in the spray nozzle 5.
  • the synthetic silica is pumped from the storage container 10 into the pipes 15 and 16 by means of the pump 14.
  • the pipes 15 and 16 are provided with the butterfly valves 17 and 18.
  • the pipelines 15 and 16 are connected to the branch lines 19 and 20 via the butterfly valves 17 and 18.
  • the branch lines 19 and 20 are connected to the hose line 23 via the butterfly valves 21 and 22.
  • branch lines 19 and 20 are connected to the hose line 26 via the check valves 24 and 25.
  • the hose line 23 is connected to the compressor and introduces the compressed air into the feed device.
  • the hose line 26 is connected to the valve 13 and, via the valve 13, leads the mixture of synthetic silica and compressed air into the spray nozzle 5.
  • branch lines 19 and 20 are provided with the butterfly valves 27 and 28.
  • the butterfly valves 27 and 28 are connected to the lines 29 and 30, which are continued together in the line 31 and are connected to the reservoir 10.
  • the synthetic silica is fed alternately into the compressed air stream via the shut-off valves 17 and 18 into the branch lines 19 and 20.
  • the overpressure when filling the pipeline 19 is compensated via the lines 30 and 31 in the reservoir 10.
  • the compressed air flow is simultaneously passed via the opened shut-off valve 21 and the open non-return valve 24 into the hose line 26 through the branch line 20 to the branch line 19.
  • the butterfly valves 18 and 27 are closed.
  • the flap 22 is opened and the compressed air flow conveys the synthetic silica from the branch line 19 via the open non-return flap 25 into the hose line 26.
  • branch line 20 is filled with synthetic silica via the opened butterfly valve 18.
  • the speed-determining step is to fill the branch lines 19 or 20 with synthetic silica.
  • the synthetic silica is pumped from the storage container 10 into the pipes 32, 33, 34 and 35 by means of the pump 14.
  • the synthetic silica is supplied to the branch lines 36, 37, 38 and 39 via the shut-off valves 40, 41, 42 and 43.
  • the compressed air is supplied to the branch lines 36, 37, 38 and 39 via the shut-off valves 44, 45, 46 and 47.
  • the compressed air is supplied from the compressor via line 57.
  • the branch lines 36, 37, 38 and 39 are shut off during the filling with synthetic silica by means of the non-return flaps 58, 59, 60 and 61.
  • the mixture of compressed air and synthetic silica is led out of the feed device via line 62.
  • the device according to FIG. 3 has four, instead of two, branch lines which can be filled with synthetic silica.
  • the device according to FIG. 3 enables the compressed air to be charged more quickly with synthetic silica.
  • the device according to FIG. 3 is operated in 4-stroke operation.
  • the synthetic silica can be used in the process according to the invention, which are described in Winnacker-Riechler, Chemical Technology, Volume 3, Inorganic Technology II, 4th Edition, Carl Hauser Verlag Kunststoff, Vienna 1983, pages 75 to 90.
  • the precipitated silicas can be used unmilled or steam jet milled or spray dried or spray dried and milled.
  • the following precipitated silicas can be used, with the precipitated silica FK 320 DS being given the delay.
  • the pH value is determined electrometrically with a glass electrode and a pH meter.
  • the pH value of silicas is generally in the neutral range, that of silicates in the weakly alkaline range.
  • the sieve residue is a key figure for the fine particle size.
  • the sieve residue is determined according to the Mocker in order to record the fractions of non-dispersible or difficult-to-disperse fractions found in precipitated silicas and silicates.
  • a silica suspension is rinsed through the sieve at 4 bar water pressure.
  • the sieve is then dried and the sieve residue is weighed out. 45 micrometer sieves are used, which correspond to 325 mesh (according to ASTM).
  • the surface of silicas and silicates is measured in m2 / g using the BET method.
  • the process is based on the adsorption of gaseous nitrogen at the temperature of the liquid nitrogen.
  • the Haul and Dümbgen Areameter method can be used to advantage. Calibration is required. Both the “inner” and the “outer” surface are detected.
  • the average size of the primary particles can be determined using electron microscopic images. For this purpose, the diameters of approx. 3,000 - 5,000 particles are determined, the arithmetic mean of which is calculated.
  • the individual primary particles are generally not isolated, but are combined to form aggregates and agglomerates.
  • the "agglomerate" particle size of precipitated silicas and silicates depends on the grinding process.
  • the precipitation products contain a small proportion of physically bound water. After drying in a drying cabinet at 105 ° C. for 2 hours, most of the physically bound water has been removed.
  • the precipitated silica FK 320 DS is a precipitated silica which was steam-jet milled after the rotary kiln drying.
  • the precipitated silica Durosil is an unmilled rotary kiln-dried precipitated silica.
  • Precipitated silica Sipernat 22 is a spray-dried precipitated silica.
  • Precipitated silica Sipernat 22 S is a spray-dried and ground precipitated silica.

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  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Air Transport Of Granular Materials (AREA)
  • On-Site Construction Work That Accompanies The Preparation And Application Of Concrete (AREA)
  • Silicon Compounds (AREA)
  • Lining And Supports For Tunnels (AREA)
  • Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)

Abstract

Method for the continuous dosing of powdery substances, preferably synthetic silica, by means of high-pressure gas, especially by mean of compressed air, in which in a multiple, at least double line the supply of high-pressure gas is alternatingly interrupted in a branch line, the powdery substance is filled into the branch line and the powdery substance is subsequently transported further by the high-pressure gas. Device for the continuous dosing of powdery substances by means of compressed gas, which is arranged so that a multiple, at least double line which comes together again after branching is provided with a throttle valve and a nonreturn valve in the branch lines in the direction of flow of the high-pressure gas, whereby the branch lines are connected via a throttle valve to a storage silo for the powdery substance and also to an aeration tube.

Description

Die Erfindung betrifft ein Verfahren und eine Vorrichtung zum kontinuierlichen Dosieren von pulverförmigen Stoffen, insbesondere von pulverförmiger synthetischer Kieselsäure mittels Preßgas.The invention relates to a method and a device for the continuous dosing of powdery substances, in particular of powdery synthetic silica by means of pressurized gas.

Es ist bekannt, im Hoch- und Tiefbau, vor allem beim Tunnelbau, Spritzbeton zu verwenden (vgl. S+t 40 (1986), S. 3).It is known to use shotcrete in civil engineering, especially in tunnel construction (cf. S + t 40 (1986), p. 3).

Durch den Zusatz an synthetischer Kieselsäure wird die Stellwirkung der Spritzbetons spontan erhöht, was sich durch eine Erhöhung der anhaftenden Betonmenge respektive einem geringerem Abprall deutlich bemerkbar macht. Der von der Wandung abgenommene Beton erbringt im Vergleich zu einem Beton, der keine synthetische Kieselsäure enthält, eine Reduzierung des Ausbreitmaßes um 20 bis 25 %.The addition of synthetic silica increases the positioning effect of the shotcrete spontaneously, which is clearly noticeable through an increase in the amount of concrete adhering or a lower rebound. The concrete removed from the wall reduces the slump by 20 to 25% compared to a concrete that does not contain synthetic silica.

Die Einbringung und die exakte Dosierung der synthetischen Kieselsäure in den Spritzbeton während des Auftragens bergen große Probleme in sich. So führt man zum Beispiel die synthetische Kieselsäure neben der Betonmasse und der Förderluft über eine dritte Zuleitung direkt an der Spritzdüse zu.The introduction and the exact dosing of the synthetic silica into the shotcrete during application pose major problems. For example, in addition to the concrete mass and the conveying air, the synthetic silica is fed directly to the spray nozzle via a third feed line.

Die dabei erreichbare Vermischung ist jedoch völlig unzureichend, was an dem Kieselsäurenebel bei Austritt aus der Düse deutlich wird.However, the mixing that can be achieved is completely inadequate, which is evident from the silica mist when it emerges from the nozzle.

Günstiger wäre es vermutlich, die Kieselsäure direkt in den Förderluftstrom einzubringen (vgl. z.B. US-A-4 234 272).It would probably be more favorable to introduce the silica directly into the conveying air flow (see e.g. US-A-4,234,272).

Dies läßt sich aber mit den bekannten Pumpen, wie z. B. Depa-Pumpen, nicht durchführen, weil der Druck in der Luftleitung während des Betriebes ca. 8 bar beträgt.This can be done with the known pumps, such as. B. Depa pumps, do not carry out because the pressure in the air line is approximately 8 bar during operation.

Die Aufgabe der Erfindung besteht darin, den Zusatz an synthetischer Kieselsäure zu Spitzbeton genau zu dosieren und mit dem Spritzbeton homogen zu vermischen.The object of the invention is to precisely meter the addition of synthetic silica to pointed concrete and to mix it homogeneously with the shotcrete.

Gegenstand der Erfindung ist ein Verfahren zum kontinuierlichen Dosieren von pulverförmigen Stoffen, insbesondere synthetischer Kieselsäure, mittels Preßgas, vorzugsweise mittels Preßluft, welches dadurch gekennzeichnet ist, daß man in einer mehrfach, mindestens zweifach geführten Preßgas führenden Leitung alternierend die Preßgaszufuhr in einer Zweigleitung unterbricht, den pulverförmigen Stoff in die Zweigleitung einfüllt und anschließend den pulverförmigen Stoff mittels des Preßgases weiterbefördert.The invention relates to a process for the continuous metering of powdery substances, in particular synthetic silica, by means of pressurized gas, preferably by means of pressurized air, which is characterized in that the pressurized gas supply in a branch pipe is alternately interrupted in a pressurized gas pipe which is guided at least twice Pouring powdered substance into the branch line and then conveying the powdered substance further by means of the pressurized gas.

In einer bevorzugten Ausführungsform der Erfindung kann die Preßgas führende Leitung vierfach in Zweigleitungen geführt werden.In a preferred embodiment of the invention, the line carrying the pressurized gas can be routed four times in branch lines.

Während des Unterbrechens der Preßgaszufuhr kann, um ein Rückschlagen des Preßgases aus der Zusammenführung der Mehrfachführung der Leitung in die Zweigleitung zu verhindern, die Zweigleitung durch eine Rückschlagkappe abgeschlossen werden.During the interruption of the pressurized gas supply, in order to prevent the pressurized gas from kicking back from the merging of the multiple guide of the line into the branch line, the branch line can be closed off by a check cap.

Während des Befüllens der Zweigleitung kann der entstehende Überdruck über eine Absperrklappe und eine weitere Leitung, z.B. in das Silo, das den pulverförmigen Stoff beinhaltet, ausgeglichen werden.During the filling of the branch line, the resulting excess pressure can be shut off via a butterfly valve and another line, e.g. into the silo that contains the powdered material.

Die Beförderung des pulverförmigen Stoffes aus dem Silo in die Zweigleitung kann mittels bekannter Mittel, z.B. einer Pumpe, erfolgen.The powdery substance can be conveyed from the silo into the branch line by means of known means, for example a pump.

Derartige Mittel sind in der Schriftenreihe Pigmente der Degussa AG Frankfurt, Nr. 70, erschienen im Dezember 1978, beschrieben.Such agents are described in the Pigments series by Degussa AG Frankfurt, No. 70, published in December 1978.

Die Absperrung der Zweigleitungen kann mittels bekannter Absperrklappen erfolgen.The branch lines can be shut off by means of known butterfly valves.

Ein weiterer Gegenstand der Erfindung ist eine Vorrichtung zum kontinuierlichen Dosieren von pulverförmigen Stoffen, insbesondere von synthetischer Kieselsäure, mittels Preßgas, welche dadurch gekennzeichnet ist, daß eine mehrfach, mindestens zweifach geführte Leitung, die nach der Verzweigung wieder zusammengeführt wird, in den Zweigleitungen jeweils in Strömungsrichtung des Preßgases mit einer Absperrklappe und einer Rückschlagklappe versehen ist, wobei die Zweigleitungen über jeweils eine Absperrklappe zum einen mit einem Vorratssilo für den pulverförmigen Stoff und zum anderen mit einem Entlüftungsrohr verbunden sind.Another object of the invention is a device for the continuous dosing of powdery substances, in particular synthetic silica, by means of pressurized gas, which is characterized in that a multiple, at least two-fold line, which is brought together again after the branching, in each of the branch lines The direction of flow of the pressurized gas is provided with a shut-off valve and a non-return valve, the branch lines being connected via a shut-off valve to a storage silo for the pulverulent material and to a ventilation pipe.

Das erfindungsgemäße Verfahren hat den Vorteil, daß der pulverförmige Stoff homogen ohne Substanzverlust kontinuierlich mit dem Beton vermischt wird.The process according to the invention has the advantage that the pulverulent substance is mixed homogeneously with the concrete without loss of substance.

Das erfindungsgemäße Verfahren und die erfindungsgemäße Vorrichtung werden an Hand der Zeichnung näher erläutert.The method and the device according to the invention are explained in more detail with reference to the drawing.

Es zeigen

Figur 1
die schematische Anordnung der Apparate bei der Aufbringung von Spritzbeton.
Figur 2
die erfindungsgemäßen Einspeisvorrichtung.
Figur 3
eine weitere Ausführungsform der erfindungsgemäßen Einspeisvorrichtung.
Show it
Figure 1
the schematic arrangement of the apparatus when applying shotcrete.
Figure 2
the feed device according to the invention.
Figure 3
a further embodiment of the feed device according to the invention.

Gemäß Figur 1 wird der Beton von dem Transportbetonwerk 1 mittels des Mischfahrzeuges 2 zu der Betonpumpe 3 transportiert.According to FIG. 1, the concrete is transported from the ready-mixed concrete plant 1 to the concrete pump 3 by means of the mixing vehicle 2.

Die Betonpumpe 3 befördert den Beton über das Ventil 4 zu der Spritzdüse 5. Von dort wird Beton auf die Wand 6 aufgetragen.The concrete pump 3 conveys the concrete via the valve 4 to the spray nozzle 5. From there, concrete is applied to the wall 6.

Die synthetische Kieselsäure wird von dem Silo 7 mittels des Fahrzeuges 8 oder alternativ über die Standleitung 9 in den Vorratsbehälter 10 und von dort in die Einspeisvorrichtung 11 befördert.The synthetic silica is conveyed from the silo 7 by means of the vehicle 8 or alternatively via the dedicated line 9 into the storage container 10 and from there into the feed device 11.

Von dem Kompressor wird Preßluft in die Einspeisvorrichtung 11 über die Leitung 12 geführt.Compressed air is fed from the compressor into the feed device 11 via the line 12.

Mittels der Preßluft wird die synthetische Kieselsäure von der Einspeisvorrichtung 11 über das Ventil 13 in die Spritzdüse 5 befördert und in der Spritzdüse 5 mit dem Beton vermischt.By means of the compressed air, the synthetic silica is conveyed from the feed device 11 via the valve 13 into the spray nozzle 5 and mixed with the concrete in the spray nozzle 5.

Gemäß Figur 2 wird die synthetische Kieselsäure aus dem Vorratsbehälter 10 mittels der Pumpe 14 in die Rohrleitungen 15 und 16 gepumpt. Die Rohrleitungen 15 und 16 sind mit den Absperrklappen 17 und 18 versehen. Über die Absperrklappen 17 und 18 sind die Rohrleitungen 15 und 16 mit den Zweigleitungen 19 und 20 verbunden.According to FIG. 2, the synthetic silica is pumped from the storage container 10 into the pipes 15 and 16 by means of the pump 14. The pipes 15 and 16 are provided with the butterfly valves 17 and 18. The pipelines 15 and 16 are connected to the branch lines 19 and 20 via the butterfly valves 17 and 18.

Die Zweigleitungen 19 und 20 sind über die Absperrklappen 21 und 22 mit der Schlauchleitung 23 verbunden.The branch lines 19 and 20 are connected to the hose line 23 via the butterfly valves 21 and 22.

Weiterhin sind die Zweigleitungen 19 und 20 über die Rückschlagklappen 24 und 25 mit der Schlauchleitung 26 verbunden.Furthermore, the branch lines 19 and 20 are connected to the hose line 26 via the check valves 24 and 25.

Die Schlauchleitung 23 ist mit dem Kompressor verbunden und führt die Preßluft in die Einspeisvorrichtung ein.The hose line 23 is connected to the compressor and introduces the compressed air into the feed device.

Die Schlauchleitung 26 ist mit dem Ventil 13 verbunden und führt über das Ventil 13 das Gemisch aus synthetischer Kieselsäure und Preßluft in die Spritzdüse 5.The hose line 26 is connected to the valve 13 and, via the valve 13, leads the mixture of synthetic silica and compressed air into the spray nozzle 5.

Zusätzlich sind die Zweigleitungen 19 und 20 mit den Absperrklappen 27 und 28 versehen. Die Absperrklappen 27 und 28 sind mit den Leitungen 29 und 30 verbunden, die in der Leitung 31 gemeinsam weitergeführt werden und mit dem Vorratsbehälter 10 verbunden sind.In addition, the branch lines 19 and 20 are provided with the butterfly valves 27 and 28. The butterfly valves 27 and 28 are connected to the lines 29 and 30, which are continued together in the line 31 and are connected to the reservoir 10.

Die Einspeisung der synthetischen Kieselsäure in den Preßluftstrom erfolgt wechselseitig über die Absperrklappen 17 und 18 in die Zweigleitungen 19 und 20.The synthetic silica is fed alternately into the compressed air stream via the shut-off valves 17 and 18 into the branch lines 19 and 20.

Gleichzeitig werden die Absperrklappen 21 und 22 sowie die Absperrklappen 27 und 28 betätigt.At the same time, the butterfly valves 21 and 22 and the butterfly valves 27 and 28 are actuated.

Wenn die synthetische Kieselsäure über die geöffnete Absperrklappe 17 in die Zweigleitung 19 eingeführt wird, ist die Absperrklappe 22 geschlossen und die Absperrklappe 28 geöffnet. Die Rückschlagklappe 25 ist geschlossen.When the synthetic silica is introduced into the branch line 19 via the opened butterfly valve 17, the butterfly valve 22 is closed and the butterfly valve 28 is opened. The check valve 25 is closed.

Der Überdruck beim Befüllen der Rohrleitung 19 wird über die Leitungen 30 und 31 in den Vorratsbehälter 10 ausgeglichen.The overpressure when filling the pipeline 19 is compensated via the lines 30 and 31 in the reservoir 10.

Der Preßluftstrom wird gleichzeitig über die geöffnete Absperrklappe 21 und die geöffnete Rückschlagklappe 24 in die Schlauchleitung 26 durch die Zweigleitung 20 an der Zweigleitung 19 vorbeigeführt. Die Absperrklappen 18 und 27 sind dabei geschlossen.The compressed air flow is simultaneously passed via the opened shut-off valve 21 and the open non-return valve 24 into the hose line 26 through the branch line 20 to the branch line 19. The butterfly valves 18 and 27 are closed.

Beim folgenden Taktwechsel werden gleichzeitig alle Absperrklappen und Rückschlagklappen betätigt.During the following cycle change, all butterfly valves and non-return valves are operated at the same time.

Die Klappe 22 wird dabei geöffnet und der Preßluftstrom befördert die synthetische Kieselsäure aus der Zweigleitung 19 über die geöffnete Rückschlagklappe 25 in die Schlauchleitung 26.The flap 22 is opened and the compressed air flow conveys the synthetic silica from the branch line 19 via the open non-return flap 25 into the hose line 26.

Gleichzeitig wird die Zweigleitung 20 über die geöffnete Absperrklappe 18 mit synthetischer Kieselsäure gefüllt.At the same time, the branch line 20 is filled with synthetic silica via the opened butterfly valve 18.

Der geschwindigkeitsbestimmende Schritt ist die Befüllung der Zweigleitungen 19 oder 20 mit synthetischer Kieselsäure.The speed-determining step is to fill the branch lines 19 or 20 with synthetic silica.

Gemäß Figur 3 wird die synthetische Kieselsäure aus dem Vorratsbehälter 10 mittels der Pumpe 14 in die Rohrleitungen 32, 33, 34 und 35 gepumpt.According to FIG. 3, the synthetic silica is pumped from the storage container 10 into the pipes 32, 33, 34 and 35 by means of the pump 14.

Die Zufuhr der synthetischen Kieselsäure zu den Zweigleitungen 36, 37, 38 und 39 erfolgt über die Absperrventile 40, 41, 42 und 43.The synthetic silica is supplied to the branch lines 36, 37, 38 and 39 via the shut-off valves 40, 41, 42 and 43.

Die Preßluftzufuhr zu den Zweigleitungen 36, 37, 38 und 39 erfolgt über die Absperrventile 44, 45, 46 und 47.The compressed air is supplied to the branch lines 36, 37, 38 and 39 via the shut-off valves 44, 45, 46 and 47.

Der Überdruck, der beim Befüllen der Zweigleitungen 36, 37, 38 und 39 mit synthetischer Kieselsäure anfällt, wird über die Absperrventile 48, 49, 50 und 51 und die Leitungen 52, 53, 54, 55 und 56 in den Vorratsbehälter 10 ausgeglichen.The excess pressure which arises when the branch lines 36, 37, 38 and 39 are filled with synthetic silica is compensated for by the shut-off valves 48, 49, 50 and 51 and the lines 52, 53, 54, 55 and 56 into the storage container 10.

Die Preßluftzufuhr vom Kompressor erfolgt über die Leitung 57.The compressed air is supplied from the compressor via line 57.

Die Absperrung der Zweigleitungen 36, 37, 38 und 39 während des Befüllens mit synthetischer Kieselsäure erfolgt durch die Rückschlagklappen 58, 59, 60 und 61.The branch lines 36, 37, 38 and 39 are shut off during the filling with synthetic silica by means of the non-return flaps 58, 59, 60 and 61.

Das Gemisch aus Preßluft und synthetischer Kieselsäure wird über die Leitung 62 aus der Einspeisvorrichtung herausgeführt.The mixture of compressed air and synthetic silica is led out of the feed device via line 62.

Die Vorrichtung gemäß Figur 3 hat gegenüber der Vorrichtung gemäß der Figur 2 anstatt zwei, vier Zweigleitungen, die mit synthetischer Kieselsäure gefüllt werden können.Compared to the device according to FIG. 2, the device according to FIG. 3 has four, instead of two, branch lines which can be filled with synthetic silica.

Da die Befüllung mit synthetischer Kieselsäure der geschwindigkeitsbestimmende Schritt ist, kann durch die Vorrichtung gemäß Figur 3 eine schnellere Beschickung der Preßluft mit synthetischer Kieselsäure erzielt werden.Since the filling with synthetic silica is the speed-determining step, the device according to FIG. 3 enables the compressed air to be charged more quickly with synthetic silica.

Um eine gleichmäßige Beschickung der Preßluft mit synthetischer Kieselsäure zu erzielen, wird die Vorrichtung gemäß Figur 3 im 4-Takt-Betrieb gefahren.In order to achieve a uniform loading of the compressed air with synthetic silica, the device according to FIG. 3 is operated in 4-stroke operation.

Als synthetische Kieselsäure kann man bei dem erfindungsgemäßen Verfahren Kieselsäuren einsetzen, die in Winnacker-Küchler, Chemische Technologie, Band 3, Anorganische Technologie II, 4. Auflage, Carl Hauser Verlag München, Wien 1983, Seite 75 bis 90 beschrieben werden.The synthetic silica can be used in the process according to the invention, which are described in Winnacker-Küchler, Chemical Technology, Volume 3, Inorganic Technology II, 4th Edition, Carl Hauser Verlag Munich, Vienna 1983, pages 75 to 90.

Von besonderer Bedeutung sind pyrogene Kieselsäuren, die auf dem Wege des Flammenhydrolyse hergestellt wurden sowie Fällungskieselsäuren, wobei bei dem erfindungsgemäßen Verfahren den Fällungskieselsäuren der Vorzug gegeben wird.Of particular importance are pyrogenic silicas which have been produced by flame hydrolysis and precipitated silicas, preference being given to the precipitated silicas in the process according to the invention.

Die Fällungskieselsäuren können unvermahlen oder dampfstrahlvermahlen bzw. sprühgetrocknet oder sprühgetrocknet und vermahlen eingesetzt werden.The precipitated silicas can be used unmilled or steam jet milled or spray dried or spray dried and milled.

Beispielhaft können die folgenden Fällungskieselsäuren eingesetzt werden, wobei der Fällungskieselsäure FK 320 DS den Verzug gegeben wird.

Figure imgb0001
Figure imgb0002
Figure imgb0003
 For example, the following precipitated silicas can be used, with the precipitated silica FK 320 DS being given the delay.
Figure imgb0001
Figure imgb0002
Figure imgb0003

Die Bestimmung der physikalisch-chemischen Kenndaten erfolgt nach den folgenden Methoden:The physical-chemical characteristics are determined using the following methods:

pH-Wert (nach DIN 53 200)pH value (according to DIN 53 200)

Der pH-Wert wird elektrometrisch mit einer Glaselektrode und einem pH-Meter ermittelt. Der pH-Wert von Kieselsäuren liegt im allgemeinen im neutralen, der von Silikaten im schwach alkalischen Bereich.The pH value is determined electrometrically with a glass electrode and a pH meter. The pH value of silicas is generally in the neutral range, that of silicates in the weakly alkaline range.

Siebrückstand (nach DIN 53 580)Sieve residue (according to DIN 53 580)

Eine Kennzahl für die Feinteiligkeit ist der Siebrückstand. Zur Erfassung der in kleinsten Mengen in Fällungskieselsäuren und Silikaten vorkommenden Anteile nicht oder schwerdispergierbarer Anteile, wird der Siebrückstand nach Mocker bestimmt. Bei diesem Verfahren wird eine Kieselsäuresuspension mit 4 bar Wasserdruck durch das Sieb gespült. Das Sieb wird anschließend getrocknet und der Siebrückstand ausgewogen. Zur Anwendung kommen 45 Micrometer-Siebe, die 325 mesh (nach ASTM) entsprechen.The sieve residue is a key figure for the fine particle size. The sieve residue is determined according to the Mocker in order to record the fractions of non-dispersible or difficult-to-disperse fractions found in precipitated silicas and silicates. In this process, a silica suspension is rinsed through the sieve at 4 bar water pressure. The sieve is then dried and the sieve residue is weighed out. 45 micrometer sieves are used, which correspond to 325 mesh (according to ASTM).

Oberfläche nach BET (DIN 66 131)Surface according to BET (DIN 66 131)

Die Oberfläche von Kieselsäuren und Silikaten wird nach der BET-Methode in m²/g gemessen.The surface of silicas and silicates is measured in m² / g using the BET method.

Das Verfahren beruht auf der Adsorption von gasförmigem Stickstoff bei der Temperatur des flüssigen Stickstoffs. Die Areameter-Methode nach Haul und Dümbgen kann vorteilhaft angewandt werden. Eine Eichung ist erforderlich. Es wird sowohl die "innere" als auch die "äußere" Oberfläche erfaßt.The process is based on the adsorption of gaseous nitrogen at the temperature of the liquid nitrogen. The Haul and Dümbgen Areameter method can be used to advantage. Calibration is required. Both the "inner" and the "outer" surface are detected.

Mittlere Größe der PrimärteilchenMedium size of the primary particles

Die mittlere Größe der Primärteilchen läßt sich über elektronenmikroskopische Aufnahmen bestimmen. Hierzu werden die Durchmesser von ca. 3.000 - 5.000 Teilchen bestimmt, deren arithmetisches Mittel errechnet wird. Die einzelnen Primärteilchen liegen im allgemeinen nicht isoliert vor, sondern sind zu Aggregaten und Agglomeraten vereinigt. Die "Agglomerat"-Teilchengröße von Fällungskieselsäuren und Silikaten hängt vom Vermahlungsprozeß ab.The average size of the primary particles can be determined using electron microscopic images. For this purpose, the diameters of approx. 3,000 - 5,000 particles are determined, the arithmetic mean of which is calculated. The individual primary particles are generally not isolated, but are combined to form aggregates and agglomerates. The "agglomerate" particle size of precipitated silicas and silicates depends on the grinding process.

Stampfdichte (nach DIN 53 194)Tamped density (according to DIN 53 194)

Es handelt sich um eine Maßangabe für das Gewicht des pulverförmigen Produktes. Ca. 200 ml Kieselsäure werden in dem Meßzylinder des Stampfvolumeters 1.250 mal gestampft. Aus der Einwaage und dem Volumen wird die Stampfdichte berechnet und in g/l angegeben.It is a measure of the weight of the powdered product. Approx. 200 ml of silica are mashed 1,250 times in the measuring cylinder of the ramming volumeter. The tamped density is calculated from the sample weight and the volume and given in g / l.

Trocknungsverlust (nach DIN 55 921)Loss on drying (according to DIN 55 921)

Die Fällungsprodukte enthalten einen kleinen Anteil physikalisch gebundenen Wassers. Nach 2 Stunden Trocknung im Trockenschrank bei 105 °C ist die Hauptmenge des physikalisch gebundenen Wassers entfernt.The precipitation products contain a small proportion of physically bound water. After drying in a drying cabinet at 105 ° C. for 2 hours, most of the physically bound water has been removed.

Glühverlust (nach DIN 55 921)Loss on ignition (according to DIN 55 921)

Nach 2 Stunden Glühzeit bei 1000 °C ist auch das chemisch in Form von Silanolgruppen gebundene Wasser entfernt. Der Glühverlust wird an der 2 h bei 105 °C getrockneten Substanz bestimmt.After 2 hours of annealing at 1000 ° C, the water chemically bound in the form of silanol groups is also removed. The loss on ignition is determined on the substance dried at 105 ° C. for 2 h.

Die Fällungskieselsäure FK 320 DS ist eine Fällungskieselsäure, die nach der Drehrohrtrocknung dampfstrahlvermahlen wurde.The precipitated silica FK 320 DS is a precipitated silica which was steam-jet milled after the rotary kiln drying.

Die Fällungskieselsäure Durosil ist eine unvermahlene drehrohrgetrocknete Fällungskieselsäure.The precipitated silica Durosil is an unmilled rotary kiln-dried precipitated silica.

Die Fällungskieselsäure Sipernat 22 ist eine sprühgetrocknete Fällungskieselsäure.Precipitated silica Sipernat 22 is a spray-dried precipitated silica.

Die Fällungskieselsäure Sipernat 22 S ist eine sprühgetrocknete und vermahlene Fällungskieselsäure.Precipitated silica Sipernat 22 S is a spray-dried and ground precipitated silica.

Claims (2)

  1. A process for the continuous dosing of powder-form materials by compressed gas, characterized in that, in an alternating sequence in a compressed gas line branched several times but at least twice, the supply of compressed gas is interrupted in a branch line, the powder-form material is introduced into the branch line and is then further transported by the compressed gas.
  2. An apparatus for carrying out the process claimed in claim 1, characterized in that a line branched several times but at least twice, merging again after branching, is provided in the branch lines (19,20), in the direction of flow of the compressed gas, with a shut-off flap (21,22) and a non-return flap (24,25), the branch lines (19,20) being connected through a shut-off flap (17,18,27,28) on the one hand to a storage silo (10) for the powder-form material and, on the other hand, to a vent pipe (31).
EP88102609A 1987-04-30 1988-02-23 Method and device for continuously proportioning powdered materials using a gas under pressure Expired - Lifetime EP0289721B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT88102609T ATE71573T1 (en) 1987-04-30 1988-02-23 METHOD AND DEVICE FOR CONTINUOUS DOSING OF POWDER MATERIALS BY MEANS OF COMPRESSED GAS.

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DE19873714387 DE3714387A1 (en) 1987-04-30 1987-04-30 METHOD AND DEVICE FOR CONTINUOUSLY DOSING POWDER-SHAPED SUBSTANCES BY MEANS OF COMPRESSED GAS
DE3714387 1987-04-30

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EP0289721A2 EP0289721A2 (en) 1988-11-09
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EP0289721B1 true EP0289721B1 (en) 1992-01-15

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Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NO162848C (en) * 1987-09-11 1990-02-28 Elkem As PROCEDURE FOR ADDING SILICA DUST TO A DRY SPRAYTE CONCRETE MIXTURE.
JPH07103691B2 (en) * 1990-06-20 1995-11-08 東亞合成株式会社 Method for spraying quick-setting spray material
DE4232112A1 (en) * 1992-09-25 1994-03-31 Celcommerz High Chem Produkte Addn. of powdered or fibrous filler to viscous fluid and process appts. - involves adding filler to large porous sack, extracting from sack base, breaking up compacted filler and feeding directly to viscous material
DE4329568C2 (en) * 1993-09-02 1997-04-17 Kraus Hans Bernd Device for conveying a dry, spreadable building material and method for using this device in earth building
DE4414233A1 (en) * 1994-04-23 1995-10-26 Wuerschum Gmbh Device for measuring powdered or granular material to be weighed
NO962925L (en) * 1996-03-29 1997-09-30 Olav Geir Tjugum Spray Concrete Accelerator, and Methods and Equipment for Addition to Spray Concrete
US6123484A (en) * 1997-01-29 2000-09-26 Fujita; Takatoyo Soil pile and method for constructing the same
DE10023170B4 (en) * 2000-05-11 2006-04-27 Kurt Wolf VELCO Gesellschaft für Förder-, Spritz- und Silo-Anlagen mbH Device for moistening dry spraying masses in the conveying line
DE10308722A1 (en) * 2003-02-28 2004-09-09 Degussa Ag Homogenization of nanoscale powders
DE102005006601A1 (en) * 2005-02-11 2006-08-24 Harro Höfliger Verpackungsmaschinen GmbH Method and device for transporting powdered product through a pipe
US7942566B1 (en) * 2005-10-11 2011-05-17 Flyashdirect, Ltd. Fly ash treatment system and method of use thereof
US7938571B1 (en) 2005-10-11 2011-05-10 Flyashdirect, Ltd. Fly ash treatment system and method of use thereof
WO2015069990A1 (en) * 2013-11-07 2015-05-14 Air Krete, Inc. A progressive bubble generating system used in making cementitous foam
KR101847758B1 (en) * 2014-01-24 2018-04-10 에프. 호프만-라 로슈 아게 Method of manufacturing uni- and no-code test stripes
CN104213927B (en) * 2014-08-26 2016-05-04 班珊珊 Accelerator powder gas generator

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1684370A (en) * 1928-09-11 Art of transporting mixed materials
US3625724A (en) * 1968-09-23 1971-12-07 Altrona Corp Cellular concrete and method for producing the same
DE2130257C3 (en) * 1970-06-18 1975-04-03 Challenge-Cook Bros. Inc., Industry, Calif. (V.St.A.) Method for spraying concrete or the like. and device for carrying out the method
US3779519A (en) * 1971-06-07 1973-12-18 Tetradyne Corp Concrete placement
DE7131296U (en) * 1971-08-16 1971-12-09 Wibau Gmbh DEVICE FOR THE PROPORTIONAL ALLOCATION OF POWDERED SETTING ACCELERATORS TO FLOWING CEMENT CONCRETE
US3840186A (en) * 1972-10-24 1974-10-08 J Broadfoot Unit for feeding difficult to feed materials
US4292351A (en) * 1978-04-28 1981-09-29 Yasuro Ito Method of blasting concrete
JPS593368B2 (en) * 1978-10-02 1984-01-24 極東開発工業株式会社 Constant weight and constant volume supply device for powder and granular materials
US4234272A (en) * 1978-10-06 1980-11-18 Laseter Douglas E Material conveyor
US4298288A (en) * 1980-01-25 1981-11-03 Anthony Industries, Inc. Mobile concreting apparatus and method
JPS56124465A (en) * 1980-03-05 1981-09-30 Gijutsu Shigen Kaihatsu Kk Method and apparatus for spraying cement mortar, etc.
JPS6026506A (en) * 1983-07-25 1985-02-09 Kawasaki Heavy Ind Ltd Device for distributing powdered material
JPS6040570U (en) * 1983-08-22 1985-03-22 芦沢　七郎 Sealed water tank
DE3703761A1 (en) * 1987-02-07 1988-08-25 Hochtief Ag Hoch Tiefbauten DEVICE FOR APPLYING A SPRAY CONCRETE LAYER

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DE3714387A1 (en) 1988-11-10
EP0289721A3 (en) 1990-10-31
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JPS63287541A (en) 1988-11-24
ES2027714T3 (en) 1992-06-16

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