Classifications

• • 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
  • B28C7/02—Controlling the operation of the mixing
• • 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
  • B01F23/50—Mixing liquids with solids
  • B01F23/53—Mixing liquids with solids using driven stirrers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
  • B01F27/21—Mixers with rotary stirring devices in fixed receptacles; Kneaders characterised by their rotating shafts
  • B01F27/2123—Shafts with both stirring means and feeding or discharging means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
  • B01F27/80—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis
  • B01F27/91—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis with propellers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
  • B01F35/71—Feed mechanisms
  • B01F35/717—Feed mechanisms characterised by the means for feeding the components to the mixer
  • B01F35/718—Feed mechanisms characterised by the means for feeding the components to the mixer using vacuum, under pressure in a closed receptacle or circuit system
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
  • B01F35/80—Forming a predetermined ratio of the substances to be mixed
  • B01F35/82—Forming a predetermined ratio of the substances to be mixed by adding a material to be mixed to a mixture in response to a detected feature, e.g. density, radioactivity, consumed power or colour
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28C—PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28C5/00—Apparatus or methods for producing mixtures of cement with other substances, e.g. slurries, mortars, porous or fibrous compositions
  • B28C5/08—Apparatus or methods for producing mixtures of cement with other substances, e.g. slurries, mortars, porous or fibrous compositions using driven mechanical means affecting the mixing
  • B28C5/10—Mixing in containers not actuated to effect the mixing
  • B28C5/12—Mixing in containers not actuated to effect the mixing with stirrers sweeping through the materials, e.g. with incorporated feeding or discharging means or with oscillating stirrers
  • B28C5/1238—Mixing in containers not actuated to effect the mixing with stirrers sweeping through the materials, e.g. with incorporated feeding or discharging means or with oscillating stirrers for materials flowing continuously through the mixing device and with incorporated feeding or discharging devices
  • B28C5/1253—Mixing in containers not actuated to effect the mixing with stirrers sweeping through the materials, e.g. with incorporated feeding or discharging means or with oscillating stirrers for materials flowing continuously through the mixing device and with incorporated feeding or discharging devices with discharging devices
• • 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

Definitions

• the present invention relates to a device for projecting a mixture
• a device for projecting a mixture comprising a pump equipped with a compression stage and a rotor, a projection lance and a mixer provided with at least one phase feed. liquid and at least one solid phase feed, said mixer having a mixing chamber, said mixing chamber comprising an output connected to an inlet of said pump compression stage, said compression stage comprising an output of said mixture connected to a first inlet of the projection lance arranged to project said mixture through a second projection orifice in an external environment, said mixer comprising at least one rotary kneading arm passing through said mixing chamber, arranged to be set in motion at a rotational speed by a motor and for kneading said solid phase with said liquid phase to form a kneading mixture, said kneading arm e comprising an eccentric screw in proiongement, extending through said outlet of the mixing chamber and ending in said compression stage of said pump, thus forming the pump rot
• This device comprises an arrival of said mixture provided by a Sparrow pump, the mixture being pumped to a projection lance connected by one of its ends to the pump, to be then projected by a nozzle placed in the extension of a second end of the spear.
• This device is used to apply a layer of a projected mixture from a liquid phase and a solid phase.
• This variation in water flow affects the quality of the mixture to be sprayed. For example, if the water flow increases, the mixture formed is too liquid and does not stick, and when projected, does not hold uniformly on the support, conversely, if the water flow decreases, the mixture formed is too thick and its projection is of lower quality since the projection of a too thick mixture compromises the uniformity of the mixing layer on the wall.
• the water flow rate may be low enough to obtain a mixture in the mixing chamber which has a high viscosity so that the rotational movement of the rotary arm is blocked at the compression chamber which can lead to a breakage of the latter which is always driven in a rotational movement.
• This risk is even higher than the mixture is characterized by a fast setting time.
• the projection devices known in the state of the art are provided with an emergency stop system for the rotation of the rotating arm, this system comprises a water flow sensor connected to a control means which controls the stopping of the rotation of the arm and therefore of the projection when the water flow passes under a predefined threshold value.
• the aim of the invention is to overcome the drawbacks of the state of the art by providing a projection device which makes it possible to guarantee a homogeneous and constant consistency of the mixture at the mixer outlet and at a constant or at least quasi-constant flow rate during the process. projection so that the projection of the mixture is as uniform as possible.
• a device as indicated at the beginning, characterized in that it comprises a control means connected to a rheological variable sensor of said mixture and to a speed regulator of said engine, said sensor being associated with said projection lance of said mixture and said speed regulator being arranged to act on said speed of rotation of the mixing arm, said control means being arranged to receive a signal transmitted by the variable sensor and to send a signal to said controller based on a value measured by the sensor.
• the consistency of the mixture is determined at any time during the projection by measuring a rheological variable value which is transmitted to the control means in the form of a signal. If this measured rheological variable value differs from a predetermined threshold value corresponding to a desired mixing consistency, the control means in turn sends a signal to the regulator which changes the rotational speed of the arm until the mixture at the end of mixing has the desired consistency.
• the projection device according to the invention allows a correction of the consistency of the mixture made during the formation of the mixture by mixing, which allows on the one hand to have a device more responsive to variations in flow rates in the liquid phase or in the solid phase, and the regulation is simpler because it involves the use of only one sensor at the level of the projection lance.
• the present invention is based on the surprising effect that the modification of the speed of rotation of the kneading arm makes it possible to maintain a homogeneous and constant consistency over time while not affecting, or at least affecting, only very little, the output flow of the mixture so that the projection of the mixture is as uniform as possible.
• control means is a proportional-integral-derivative type corrector.
• This type of regulator has the advantage of being easy to implement physically and can therefore be applied to regulate a device already in production. It also makes it possible to adapt the regulation to the evolution of parameters such as the wear of the parts of the device, such as the rotor and the stator, or the increase of the temperature in the compression stage.
• said regulator is a frequency converter and the motor is an AC motor.
• the senor is a pressure sensor, preferably a strain gauge.
• said liquid phase comprises water.
• said solid phase is a pulverulent inorganic material, in particular hydraulic material, preferably comprising at least one element chosen from the group consisting of gypsum, sand and dry cement.
• said liquid phase supply is located at a level lower than that of said solid phase supply.
• the compression stage and a lower part of the mixing chamber are constantly saturated with water so that, when kneading and pumping the mixture, there is no lumping or air bubble in the mixture.
• the invention also relates to a process comprising the preparation of a mixture of a solid phase or of a pasty phase with a liquid phase, comprising:
• a measure of at least one rheological variable of said mixture preferably the pressure, giving a first rheological variable value which is coded in a first signal
• Said mixing arm passing through said mixing chamber comprises in its extension an eccentric screw extending through an outlet of the mixing chamber connected to a mixing chamber. input of a compression stage of a pump, which eccentric screw extends through the outlet and terminates in a compression stage of a pump where said step of pumping said mixture takes place, which eccentric screw thus forming a rotor of the pump, said mixing arm controlling said second feed rate of said solid phase to said mixing chamber and said third rate of pumping said mixture
• the method is characterized in that the step of measuring said rheological variable is performed at said projection lance, said speed regulator processing said second output signal to then control said motor rotating said mixing arm and regulate said rotational speed of said mixing arm and inducing a variation simultaneously of said second feed rate of said solid phase and said third flow rate of said mixture.
• this method further comprises a first comparison step in which said first signal is compared with a first reference signal corresponding to a second reference rheological variable value with the aid of a first comparison calculator of said first reference signal. control inputting said first signal and said first reference signal to output said second signal and send it to said speed controller.
• said second signal corresponds to a difference calculated between, on the one hand, said first rheological variable value and, on the other hand, said second reference rheological variable value, said second signa! being processed at the input of said speed regulator which decodes said second signal and translates it into an output simultaneously of said second feed rate of said solid phase and said third flow rate of said mixture.
• the step of processing said second signal by said speed controller is a proportional-integral-derivative type regulation step.
• said variation of said second feed rate of said solid phase and said third pumping rate of said mixture is carried out until said at least one rheological variable reaches a predetermined value.
• said at least one rheological variable of said mixture is the pressure
• Figure 1 schematically shows the projection device according to the present invention.
• This device is particularly intended to form a mixture, for example plaster, from a liquid phase, for example water, and a solid phase, for example gypsum, and to project this mixture so as to form an even layer of this mixture for example on a wall.
• a mixture for example plaster
• a liquid phase for example water
• a solid phase for example gypsum
• the liquid phase is water and the solid phase is a pulverulent mineral material, in particular hydraulic, preferably comprising at least one element selected from the group of gypsum, sand, dry cement.
• the kneader may be fed with a pasty phase instead of a solid phase
• the pasty phase is a moist mineral material comprising at least one element selected from the group of wet cement, slaked lime, and mortar.
• said mixture has a liquid phase: solid phase ratio of between 0.3 and 1, preferably between 0.4 and 0.8, advantageously between 0.5 and 0.7.
• the projection device 1 of a mixture comprises a kneader 2 divided into a lower part corresponding to a kneading chamber 4 and an upper part 3 situated above the kneading chamber 4 and traversed by an inlet for a solid phase 5, connected to a first solid phase feed 6, and an inlet for a liquid phase 7 connected to a second liquid phase feed 8, the orifice the inlet of the liquid phase 7 being placed at a level lower than that of the inlet of the solid phase 5.
• Each of the feeds 6, 8 may optionally be connected to a container 9 which may be a hopper 9 or a tank 9 '.
• Said mixing chamber 4 is traversed by a first mixing outlet orifice 10 connected to a compression stage of a pump 11 provided with a second mixing outlet orifice 12 connected to an inlet port 13 of a lance 14 of projection.
• This lance is arranged to project the mixture from a second outlet orifice 15 connected to a projection nozzle 16 on a wall 17.
• the kneader 2 is provided with a rotary kneading arm 18 arranged to pass through the upper part 3 and the kneading chamber 4, said kneading arm possibly being provided with one or more blades 19 and extended at a first end. 20, facing the mixing outlet port 10, by an eccentric "pigtail" screw 21 which extends through the mixing outlet port 10 to terminate in the compression stage 1 1 of the pump and form a Sparrow type pump comprising a rotor which is the eccentric screw and a stator which is the compression stage.
• a double chain of sealed cavities also called "cells" to the volume defined by the dimensions and shapes of the rotor and the stator is formed.
• the cells progress along the axis of rotation of the eccentric screw of the pump, which transfers the mixture pumped from the outlet of the mixing chamber of the pump to the outlet of the mixture.
• the stator may comprise an inner wall coated with a rubberized material, this pump being arranged to simultaneously pump the solid phase from the upper part 3 to the mixing chamber 4, and the mixing of the mixing chamber to the orifice input 13 of the projection lance 14.
• the rotary kneading arm 18 is connected by a second end 22, opposite to the first end 20, to a motor 23 arranged to rotate the rotary arm at a rotational speed along an axis of rotation r passing through the ends 20 and 22 of the arm.
• the arm once rotated, kneads the solid phase with the liquid phase to form the mixture.
• the lance 14 of the projection device is associated with a rheological variable sensor 24 chosen from the following rheological variables of the mixture: pressure, viscosity, density, and stress.
• the sensor is a strain gauge measuring the pressure of the mixture at the mixing outlet.
• the device further comprises a control means 25, preferably a proportional-integral-derivative type calculator, connected by a first transmission line 11 to the sensor 24 and by a second transmission line 12 to a speed regulator 26 of the engine 23, this regulator is arranged to act on the speed of rotation of the mixing arm 18 on the basis of a value of the rheological variable measured by the sensor 24.
• a control means 25 preferably a proportional-integral-derivative type calculator, connected by a first transmission line 11 to the sensor 24 and by a second transmission line 12 to a speed regulator 26 of the engine 23, this regulator is arranged to act on the speed of rotation of the mixing arm 18 on the basis of a value of the rheological variable measured by the sensor 24.
• the control means is arranged to receive a first signal S1 emitted by the sensor 24 and send a second signal S2 to the speed regulator arranged to act on the speed of the motor via an actuator A which may be for example an inverter when said regulator 26 is a frequency converter and when the motor is an AC motor.
• the liquid phase is brought to a first fixed flow D1 from the upper part 3 to the mixing chamber 4 of the rotary kneader 2.
• the solid phase is brought to a second flow D2, which can be fixed or variable, from the upper part 3 to the mixing chamber 4.
• the solid phase is conveyed at a flow rate D3 from a first container 9 to the upper part 3 of the kneader, while the liquid phase is conveyed at a flow rate D4 from a second container 9 'to the upper part 3 of the kneader.
• the mixture is then formed by rotary kneading in the mixing chamber 4 of the liquid phase and the solid phase by the kneading arm 18 passing through this chamber and rotated at a speed of rotation by the motor 23.
• this mixture has a liquid phase: solid phase ratio between 0.3 and 1, preferably between 0.4 and 0.8, advantageously between 0.5 and 0.7.
• the mixture is then driven, by the rotational movement of the eccentric screw of the rotary arm in the compression stage 1 1, from the mixing chamber 4 to the inlet port of the projection lance 14, and passes through the Compression rack of the Moineau 11 pump that pumps the mixture to a D5 pumping rate.
• the mixture driven to the pumping rate D5, passes through the lance 14 to reach the projection nozzle 16 and be projected on the wall.
• the pumping rate D5 must be determined as a function of the length L of the lance measured between the inlet orifice 13 and the outlet orifice 15.
• stationary mode operation that is to say at a speed in which the rotational speed of the rotary arm is constant and in which the feed rates of the liquid phase D1 and the liquid phase D2 to the chamber of mixing, its delivery rates of the liquid phase D3 and the solid phase D4 to the upper part of the mixer to the upper part of the mixer, and the pumping rate D5 of the mixture to the lance do not vary as a function of time.
• the mixing chamber is mixed until a first level 27 separating the mixing chamber to the upper part 3 of the mixer.
• This plurality of layers is successively composed, from the low level of the mixer 28 passing through the mixing outlet 10, to the high level of the mixer 29: a first mixing layer located between the levels 27 and 28, a second layer the liquid phase between levels 27 and 30, and a third layer of the solid phase between levels 29 and 30.
• the rotating rotor in the stator can induce a localized temperature increase in the compression stage which causes a dilation of the rubber sheath and results in a deformation of the cells which induces a reduction in their volume which has the effect that the solid phase flow to the mixing chamber is decreased.
• the mixture produced and pumped sees its solid phase load decreased and its reduced viscosity: it is more liquid and it does not stick to the wall.
• the variation of the amount of water in the kneader can also alter the consistency of the mixture to be sprayed.
• This rheological variable value corresponds to the measurement of a parameter of the consistency of the mixture and may be, for example, the pressure of the mixture measured when the latter passes through the lance 14.
• the sensor further generates the first signal S1 transmitted to the control means 25 by the transmission line 11 which receives this first signal and generates the second signal. $ 2 sent to the speed controller 26 by the second transmission line 12.
• the speed controller then processes the second signal and controls said motor rotating said mixing arm to regulate said rotational speed of said mixing arm and thus regulate the second feed rate of said solid phase D2 and the pumping rate of the mixture D5.
• the first signal S1 is compared with a first reference signal corresponding to a second reference rheological variable value with the aid of a first comparison calculator of the control means.
• the second rheological variable value corresponds to a desired pressure value of mixture associated with a consistency of the mixture that is desired to reach the output of the projection lance.
• the first computer processes the first signal and the first reference signal as input to output the second signal S2 and send it to the speed controller.
• This second signal S2 corresponds to a difference ⁇ calculated between, on the one hand, the first rheological variable value and, on the other hand, the second reference rheological variable value.
• the difference ⁇ corresponds to an absolute difference value between the first value (value measured by the sensor) and the second value (reference value).
• the second signal corresponding to an absolute deviation value ⁇ , is then processed at the input of the speed regulator which decodes the second signal, compares with a second calculator the value of absolute deviation ⁇ at a second value absolute difference threshold. If the first absolute difference value differs from the threshold value which may be a null or non-nuile value, the regulator translates the second signal that it has received into a variation of the rotation speed of the rotary arm via the actuator A for inducing a variation at a first amplitude simultaneously of the second feed rate of said solid phase D2 and the pumping rate of the mixture D5.
• the threshold value is defined as zero, it means that it is desired that the rheological variable value measured at the level of the lance 14 is strictly equal to the second value of the reference rheological variable. On the other hand, if the threshold value is set as a non-zero value, the measured rheological variable value is allowed to deviate from that of a second amplitude corresponding to said threshold value.
• the variation of the second feed rate of said solid phase D2 and of the pumping rate of the mixture D5 is carried out until the first rheological variable value reaches the value of reference or a value within a range of values determined by a non-zero threshold value.
• the senor 24 is a strain gauge provided with a contact piece passing through the lance to be in contact with the mixture and which is arranged to undergo a deformation induced by the pressure. of the mixture.
• the strain gauge reflects this deformation undergone by the contact piece in variation of electrical resistance. This variation of electrical resistance is associated with a variation in intensity of an electric current corresponding to the signal S1 generated by the sensor and sent to the control means.
• control means is a proportional-integral-derivative type corrector.
• the first amplitude of the variation of the feed rates of the solid phase D2 and of the pumping of the mixture D5 is determined proportionally to the value of absolute difference ⁇ and to the integration of the deviation value.
• absolute in time that is to say in practice to the sum of absolute deviation values A ⁇ measured over a given period of time.
• control means 25 is connected to a remote control module T, with or without a wire, arranged to transmit to the control module the second value of reference rheological variable, c ' that is to say at the desired pressure value of the mixture associated with a consistency of the mixture that it is desired to reach at the outlet of the projection lance.
• This value is encoded via an encoding interface of the remote control module which outputs a third signal S3 and sends it to the control module which converts this third signal into said second rheological variable value.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Dispersion Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Structural Engineering (AREA)
• Mixers Of The Rotary Stirring Type (AREA)
• Accessories For Mixers (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=49385061

Family Applications (1)

Country Status (3)

Cited By (2)

Families Citing this family (11)

Family Cites Families (5)

• 2013
  • 2013-09-06 BE BE2013/0584A patent/BE1021363B1/fr not_active IP Right Cessation
• 2014
  • 2014-09-04 EP EP14759195.2A patent/EP3041600B1/de not_active Not-in-force
  • 2014-09-04 WO PCT/EP2014/068880 patent/WO2015032878A1/fr active Application Filing

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events