Classifications

• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04F—FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
  • E04F21/00—Implements for finishing work on buildings
  • E04F21/02—Implements for finishing work on buildings for applying plasticised masses to surfaces, e.g. plastering walls
  • E04F21/06—Implements for applying plaster, insulating material, or the like
  • E04F21/08—Mechanical implements
  • E04F21/12—Mechanical implements acting by gas pressure, e.g. steam pressure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
  • B01F25/30—Injector mixers
  • B01F25/31—Injector mixers in conduits or tubes through which the main component flows
  • B01F25/313—Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced in the centre of the conduit
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F2101/00—Mixing characterised by the nature of the mixed materials or by the application field
  • B01F2101/28—Mixing cement, mortar, clay, plaster or concrete ingredients
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/20—Mixing gases with liquids
  • B01F23/23—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids

Definitions

• the present invention relates to a method and an apparatus for mixing a compressed propellent gas and a slurry.
• the present of invention relates to a slurry, which contains a binding agent, such as a cement slurry used for coating walls.
• the conventional method is to apply grout or plaster or alternative cementitious coating on the walls or wall elements by spraying coating material on the walls. This can be done on both exterior end interior walls.
• the material is then in the form of a slurry, which contains a binding agent, normally cement-based or cementitious as mentioned above, and a filler such as sand for example.
• the wall surface is usually provided with some type of reinforcement. This increases both the adhesion of the slurry to the surface and enhances the mechanical strength of the resulting coating.
• the reinforcement may consist of a wire mesh net, woven glass fibre fabric etc. The reinforcement is installed separately, and this is naturally a cost-increasing factor in the process.
• This equip- ment may consist of a mixer for mixing the slurry, a pipe or flexible hose for transporting the slurry to a mouthpiece where compressed air is added to the slurry, a compressed air source and a pump for the slurry.
• the compressed air is mixed with the slurry at the outlet opening of the mouthpiece, where the compressed air is added via a separate channel on the outer perimeter of the mouthpiece, in order to achieve the spray effect.
• the slurry may be applied to the wall by means of a manually driven apparatus including a container for the slurry and a manually operated means for throwing and spreading the slurry onto the wall, mostly including some type of the shovel element.
• manual plastering equipment may be used, e.g. trowels etc.
• the purpose of the present invention is to solve the general problem of obtaining a good mixture of a slurry and a propellent gas in any context when such a mixture is used. It is also a purpose of the present invention to solve the above described problems in particular in connection with the coating of walls with a slurry containing reinforcement elements, such as fibres.
• the purpose of the present invention is achieved by the method including the advantageous features stated in the characterizing portion of claim 1 , as well as by an apparatus including the advantageous features stated in the characterizing portion of claim 5.
• the slurry is fed into the cavity, the pro- pellent gas is added to the slurry inside the cavity, the resulting gas-added slurry is allowed to undergo a first expansion step while it is still inside said cavity, before it is allowed to exit from the cavity, and it undergoes a second expansion step while exiting from the cavity into the ambient air, whereby it is sprayed onto a desired object.
• a first expansion step can be achieved in the cavity, offering a volume which is considerably larger than the relatively narrow passages available when the expansion takes place in the opening of an ordinary mouthpiece. Consequently, it will become possible to use a slurry mixed with particles or elements that are considerably larger than the filler elements, such as reinforcement ele- ments or elements used in view of obtaining a specific surface structure.
• the inventive apparatus includes a cavity surrounded by a cavity wall and in which cavity the propellent gas and the slurry are mixed, further containing an inlet opening in the cavity wall for feeding the slurry into the cavity, means for feeding the propellent gas into the cavity, whereby the slurry is brought to a first expansion step inside the cavity by the adding of the propellent gas to the slurry, and further including means for spraying the gas and slurry mixture onto a desired object, during a second expansion step.
• the slurry contains a binding agent, preferably a hydraulic binding agent, for example cement, and also a filler, such as sand, cinder, fly ash etc.
• the slurry may also contain reinforcement elements, which may be organic or inorganic. Examples of such elements are vegetable fibres in the form of soaked cutter shavings, straw, chaff, strips of corrugated cardboard or paper, etc.
• the slurry may also contain particles or elements, which gives the coating surface a certain structure, such as sand particles or gravel, plastic granules, etc.
• the means for feeding the propellent gas into the cavity include a tube connected to a gas source, and which is inserted through the wall of the cavity and is moveable inside the cavity, and has a gas outlet opening inside the cavity.
• the tube is moveable in different positions inside the cavity. These positions are chosen depending on the properties of the slurry fed into the cavity.
• the apparatus also includes means for adjusting the position of the tube inside the cavity.
• Figure 1 shows a side view, partially in cross section, of a first embodiment of an apparatus according to the present invention:
• Figure 2 shows a side view, partially in cross section, of a second embodiment of the apparatus, according to the present invention
• Figure 3 shows a side view, partially in cross section, of the second embodiment
• Figure 4 shows a side view, partially in cross section, of the second embodiment
• Figure 5 shows a side view, partially in cross section, of a third embodiment of the apparatus, according to the present invention.
• Figure 6 shows a side view, partially in cross section, of a fifth embodiment of the apparatus, according to the present invention.
• the apparatus comprises a cavity 1 into which a slurry is fed through a inlet opening 3 and propellent gas is fed into the cavity via a gas feeding means 5.
• the gas feeding means comprises a tube 6 inserted through the wall 8 of the cavity and having an outlet opening inside the cavity.
• the tube is connected to a compressed propellent gas source, not illustrated.
• the slurry inlet opening 3 is located at the bottom of a funnel shaped container 10, into which the slurry is fed.
• the slurry itself has al- ready been previously mixed in a separate mixer.
• the cavity 1 has an outlet opening 4 for the gas and slurry mixture.
• the gas/slurry outlet opening is designed as a mouthpiece with an essentially cone-shaped design.
• This outlet for the gas/slurry mixture, or spray outlet has an opening with an area (SOA) in relation to the area of the gas outlet opening (GOA) which pref- erably is in the interval of 10 to 30 times the latter.
• the tube 6 is moveable in such a way that it can adopt different positions within the cavity. This is more clearly illustrated in figures 2-4.
• the opening of the tube is directed towards the gas/slurry outlet 4.
• the tube can in fact also be removable, in order to facilitate cleaning of the tube and the outlet opening of the tube.
• FIG. 2-4 A second embodiment of the apparatus according to the present invention is illustrated in figures 2-4.
• This embodiment mainly differs from the first embodi- ment in that the slurry is not fed into the cavity via a funnel-shaped container. Instead, the slurry is fed by means of a tube or pipe 20 directly connected to the cavity 1 by means of an inlet opening 13.
• the tube 20 preferably has the same diameter as the diameter of the cavity 11.
• the means for feeding the propellent gas 15 into the cavity 20 comprise a tube 16 inserted through an opening in the cavity wall 18.
• the tube is moveable and can adopt different positions inside the cavity, as illustrated in figure 3 and figure 4. In the position adopted by the gas inlet tube illustrated in figure 3, the apparatus is particularly suitable for a slurry containing fibres or other reinforcement elements.
• this position is a position where the tube 16 is in a rearward position, i.e. with its outlet relatively close to the cavity wall.
• the gas fed into the cavity 11 mixes with the slurry fed into the cavity via the inlet 13 and the gas/slurry mixture undergoes an essentially cone-shaped, first, partial expansion step, illustrated by the cone 22.
• the mixture is then propelled towards the outlet of the cavity 14, where it undergoes a second expansion step, illustrated by the cone 23 in figure 3.
• Figure 4 illustrates the apparatus according to the second embodiment when it is adapted to a slurry, which contains little or no fibre.
• the gas inlet tube 16 is inserted further inside the cavity 11 , i.e. with its outlet further forward, in the direction towards the outlet for the gas/slurry mixture, then the po- sition illustrated in figure 3.
• the slurry and the gas are mixed in an essentially cone-shaped expansion, illustrated by the cone 32. This is also a partial expansion, in a first expansion step.
• the mixture is then directed towards the outlet of the cavity, where it undergoes a second expansion illustrated by the cone with the reference number 33. It is during the second expansion that the slurry is sprayed onto the surface, which is to be coated by the slurry material.
• a third embodiment is illustrated in figure 5. This only differs from the embodiment in figure 4, in that the outlet opening 34 for the gas and slurry mixture has a much less accentuated conical form. This allows for the spraying of a slurry containing much larger reinforcement particles or other particles or fibres.
• This slurry is fed into the cavity 31 via a tube 40 with the same diameter as the cavity, and the gas is fed into the cavity 31 by means of a feeding device 35, designed as a tube 36.
• a feeding device 35 designed as a tube 36.
• means for controlling the feed of the pro- pellent gas into the cavity may comprise a valve, not illustrated, and a pressure gauge 39.
• the gas flow and the gas pressure it is possible to control the flow of slurry through the cavity, as well as the characteristics of the spray jet. For example, if the pressure is too high, the impact veloc- ity of the spray against the surface will be too high, which will result in that larger particles in the slurry will bounce off the surface.
• the pressure must also be adapted to the friction of the slurry within the cavity.
• the gas pressure inside the tube may be in the interval 150 kPa - 700 kPa, preferably approximately 200 kPa.
• the outlet opening of the cavity 51 is not cone-shaped. Instead it has essentially the same diameter as the cavity itself and it also has essentially the same area as the slurry inlet opening 40 of the cavity.
• the gas feeding means 45 are arranged in an opening in the cavity wall, in a way similar to what has been described above.

Landscapes

• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Nozzles (AREA)
• Preparation Of Clay, And Manufacture Of Mixtures Containing Clay Or Cement (AREA)
• Application Of Or Painting With Fluid Materials (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=20416095

Family Applications (1)

Country Status (11)

Families Citing this family (2)

Family Cites Families (2)

• 1999
  • 1999-06-14 SE SE9902265A patent/SE521345C2/sv not_active IP Right Cessation
• 2000
  • 2000-06-14 AP APAP/P/2001/002364A patent/AP2001002364A0/en unknown
  • 2000-06-14 CN CN00810603A patent/CN1361713A/zh active Pending
  • 2000-06-14 AU AU55848/00A patent/AU5584800A/en not_active Abandoned
  • 2000-06-14 EP EP00941091A patent/EP1225969A1/en not_active Ceased
  • 2000-06-14 PL PL00352283A patent/PL352283A1/xx unknown
  • 2000-06-14 WO PCT/SE2000/001242 patent/WO2000076644A1/en not_active Application Discontinuation
  • 2000-06-14 CA CA002374216A patent/CA2374216A1/en not_active Abandoned
  • 2000-06-14 BR BR0012079-0A patent/BR0012079A/pt not_active IP Right Cessation
  • 2000-06-14 MX MXPA01012962A patent/MXPA01012962A/es not_active Application Discontinuation
• 2001
  • 2001-02-16 ZA ZA200101347A patent/ZA200101347B/en unknown

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events