US3885716A

US3885716A - Appliance to measure out a given volume of powder

Info

Publication number: US3885716A
Application number: US310367A
Authority: US
Inventors: Claude Marechal
Original assignee: Lafarge Ciments SA
Current assignee: LafargeHolcim Ciments SA
Priority date: 1972-04-25
Filing date: 1972-11-29
Publication date: 1975-05-27
Anticipated expiration: 1992-05-27
Also published as: FR2182283A5

Abstract

Apparatus for metering a predetermined volume of powdered material with uniform grading. Apparatus includes a calibrated receptacle fixed to an arm connected to the output shaft of a motor which moves receptacle in a horizontal direction, a joint in the arm permitting that portion of the arm connected to the receptacle to rotate on its longitudinal axis for upturning the receptacle. Means included for rotating the rotatable part of the arm and means included for returning the arm to the loading position for the receptacle and for vibrating the receptacle during at least a portion of its horizontal movement. Preferably device includes a powder feed mechanism and means for measuring powder in the receptacle.

Description

United States Patent [191 Marechal [4 1 May 27, 1975 1 1 APPLIANCE TO MEASURE OUT A GIVEN VOLUME OF POWDER [75] Inventor: Claude Marechal, Lozanne, France [30] Foreign Application Priority Data Apr. 25, 1972 France 7214569 [52] US. Cl. 222/346; 222/363; 222/404 [51] Int. Cl. ..G0lf 11/10 [58] Field of Search 141/78, 79, 124, 125, 130, 141/171, 271, 272, 273, 274, 280, 283, 284; 222/164, 166, 346, 363, 368, 404;

[56] References Cited UNITED STATES PATENTS 2,705,092 3/1955 Woodrulf 222/345 X 3,126,288 3/1964 Strasburger et a1 141/78 X 3.331.665 7/1967 Natelson 141/171 X 4/1972 Teboul [41/284 1/1973 Andersen 141/78 X Primary Examiner-Richard E. Aegerter Assistant Examiner-Frederick R. Schmidt Attorney, Agent, or Firm-Hubbell, Cohen & Stiefel [57] ABSTRACT Apparatus for metering a predetermined volume of powdered material with uniform grading. Apparatus includes a calibrated receptacle fixed to an arm connected to the output shaft of a motor which moves receptacle in a horizontal direction, a joint in the arm permitting that portion of the arm connected to the receptacle to rotate on its longitudinal axis for upturning the receptacle. Means included for rotating the totatable part of the arm and means included for returning the arm to the loading position for the receptacle and for vibrating the receptacle during at least a portion of its horizontal movement. Preferably device includes a powder feed mechanism and means for measuring powder in the receptacle.

3 Claims, 2 Drawing Figures APPLIANCE TO MEASURE OUT A GIVEN VOLUME OF POWDER This invention concerns an improved appliance for measuring out a given volume of powder. More specifically, it concerns the use of this appliance in the quantitative analysis of the free lime content of cement.

A number of physical analyses, such as the quantitative analysis of lime, involve measuring out a given quantity of the substance to be analysed.

This has previously been done with expensive, cumbersome and fragile appliances, which are impractical for use in many industrial applications, particularly for continuous regulation of a kiln in operation. To simplify matters, the details given here are confined to the analysis of free lime in cement clinker, with the possi bility this offers of regulating a kiln in operation, but the invention is obviously in no way confined to this application, given merely as an illustration.

Quantitative analysis of the free lime content ofa material such as cement clinker can be used in calculating the burning rate for an unfired material; in addition, automatic operation of a cement kiln can be regulated on the basis of the quantity of free lime in the clinker from the kiln. In fact, this has not previously been possible, since the clinker is not available until it has left the cooler, approximately half an hour after actual burning, further increasing the time needed to obtain the results of analyses, so that the free lime content of the clinker cannot be found quickly enough for kilnregulation purposes.

This invention overcomes the drawbacks of existing methods, offering a method of almost continuous analysis of free lime content, and allowing kiln-operating variables to be selected and balanced more efficiently.

Analysis of the free lime content is useful not only in automated kiln operation, but also in improving the quality and uniformity of the clinker, and consequently the cement. The invention offers manufacturers an appliance to measure out a quantity of powder for analysis by industrial techniques, and more specifically an inexpensive, compact appliance for measuring out such a sample.

The invention concerns an appliance to measure out a given volume of powder with uniform grading, comprising a calibrated receptacle fixed on an arm connected to a motor which moves it in an approximately horizontal direction, a joint allowing the part of the arm to which the receptacle is attached to rotate on its longitudinal axis, upturning the receptacle, means of producing rotation of this part of the arm, means of returning the arm to the position in which the receptacle is filled, and means of causing vibration of the receptacle during at least part of its approximately horizontal movement.

According to one feature of the invention, this appliance to measure out a given volume of powder includes a powder-feed system, and a device for levelling off the surface of the powder in the receptacle.

The joint allowing the part of the arm to which the receptacle is attached to rotate is preferably located between the motor and the receptacle.

In one embodiment of the invention, the means of producing rotation of the part of the arm to which the receptacle is attached comprises a device operating on the joint.

According to another feature of the invention, the motor is attached to a base plate, to which the device operating on the joint is attached, and which includes means for causing vibration of the receptacle.

According to yet another feature. the means for re turning the arm to the position in which the receptacle is filled includes a spring.

Vibration is preferably provided by a separate vihrator, operating either on the base or directly on the arm to which the receptacle is attached.

Other aims and advantages of the invention are shown in the following description, with reference to the accompanying drawings. The invention is of course not confined to this embodiment.

FIG. 1 is a perspective view of an appliance to measure out a given volume of powder, as proposed by the invention.

FIG. 2 is a diagram showing an automatic kilnoperating unit as proposed in the invention. using this appliance.

FIG. 1 shows an appliance 7 to measure out a given volume of powder with uniform grading, comprising a calibrated receptacle 8, fixed on an arm 9 connected to a motor 10 which drives it, thereby moving the receptacle in an approximately horizontal direction, around a circumference centered on the point 11, at which the arm 9 is attached to the vertical output shaft 12 of the motor 10.

There is a joint 13 on the arm 9, allowing part 9' of the arm 9 to rotate on its longitudinal axis, this rotation being produced by a flange 14, or similar device such as a pin. The arm also has a device to ensure that it returns the receptacle 8 to its original position, such as a spring (not shown here).

The appliance Tincludes means for causing vibration of the receptacle during part of its approximately horizontal movement. This may consist of a vibrating plate 15 operated by a separate motor (not shown here). The appliance also includes a powder-feed system 16, consisting of a hopper 17 and chute 18, which also vibrate, and the width of which corresponds to the length of the filling zone for the receptacle. A scraper 19 levels off the surface of the contents of the receptacle.

The appliance operates as follows.

The arm 9 is driven by the motor 12, so that the receptacle 8 moves along a circular path, into a filling zone (position I), where the crushed clinker from the hopper 17 is poured into it. The filling zone is the same width as the chute l8, and the receptacle 8 is filled as it moves under the chute. Simultaneously, its contents are compressed by the vibrations imparted to the arm 9. It then moves on until it reaches position II, where the surface of the contents is levelled off by a scraper 19.

The receptacle continues to position II], where a raised surface 14 operates the joint 13, upturning the receptacle and transferring the contents into a discharge funnel 3 (which feeds the container 1 in FIG. 2). A stop 20, level with the joint 13, limits rotation of the receptacle. The joint preferably consists of a toothed wheel 21, which rotates when it comes into contact with the raised surface 14, upturning the receptacle 8.

The receptacle continues along its circular path, and when the toothed wheel 21 moves away from the raised surface 14, a spring returns the arm and receptacle to the filling position. The receptacle continues until it reaches position I as before.

This appliance allows a given quantity of powder to be measured out, provided that the powder has uniform grading. Compression and levelling-off help to ensure a given volume.

The system for causing the receptacle 8 to vibrate can consist of a vibrating plate 15 on springs 23, driven by a separate motor, or a device connected to the arm and to the plate 15, consisting of a microswitch 24 and cam 25 on the arm. This unit is connected electrically to a Sinex vibrator screwed beneath the plate l5.

The unit shown in FIG. 2, which can be fitted to the kiln cooling outlet, comprises a jaw-breaker 30, vibrating chute 31, and continuous crusher 32, designed to produce samples with uniform grading, with a Blaine specific surface-area of approximately 3,500 sq.cm/g. The continuous crusher 32 is connected to the appliance 7 to measure out a given volume of powder.

At regular intervals, the appliance 7 tips a fixed volume of powder through a funnel 3 into a container 1, in which there is an electrode 6. A fixed quantity of reagent is also conveyed at regular intervals from a reagent tank 35 into the container, through a funnel 2. This appliance is connected to an electronic unit which emits a logical signal conveying the measurement to a computer, and is combined with a device to record the results obtained by conductimetric, pH-metric, potentiometric or other analytical techniques, and a unit to emit a second signal in the direction of a computer, which controls the kiln-regulating system to which the unit in FIG. 2 is attached.

This unit provides almost uninterrupted quantitative continuous analysis of the free lime content of clinker, and allows kiln-operating variables to be controlled and balanced.

The jaw-breaker 30 is preferably a Minemet-type crusher, preferably giving a grain-size of between and 4 mm. It is connected to a sampler (not shown here), beneath the clinker belt in the clinker unit (not shown here). The sample is 2 to 3 liters/hr for an hourly output of 60 tons of clinker.

The continuous crusher 32 may be a vibrating crusher, which has to be fed continuously, to ensure the required degree of fineness. The vibrating chute 31 is preferably a vibrating hopper, but may be of any other type, such as an overflow device, providing a continuous supply.

The appliance 7 allows a fixed volume of the powder supplied by the vibrating hopper 17 to be measured out.

The unit formed by the appliance 7 and container 1 operates as follows.

The motor 10 is a reducing motor 1 revolution every 3 minutes, for instance), which drives the arm 9 so that the receptacle 8 passes beneath the jet of powder from the vibrating chute 18. The receptacle is filled to its capacity of approximately 1 cc, and continues its circular movement. The device formed by a cam on the arm and a microswitch on the plate causes vibration of the arm and receptacle, compressing the powder inside the receptacle uniformly, so that a uniform weight is obtained by volumetric measurement. Any excess is removed by this vibration, and the receptacle then passes under a scraper 19, which levels off the powder at the edges. Any powder remaining on the arm is removed by conventional means.

When the receptacle 8 reaches the emptying position, the joint, which consists of a toothed wheel 21, comes into contact with the raised surface 14, and completes a 180 movement, causing the part 9' of the arm 9 to rotate on its longitudinal axis. A device similar to the one used during the filling phase. consisting of a cam and microswitch, can be used here to vibrate the receptacle 8 in its upturned position, to ensure complete emptying. The arm then comes to rest in an intermediate position, and the starting signal for a new weighing cycle comes from the analysis container 1.

The powder is conveyed into the container 1 through the funnel 3, into which the receptacle 8 has been emptied. The samples of powder may consist of l g of clinker, fed into the container every l5 minutes. Simultaneously, l00 ml of glycol are conveyed to the container from a tank 35. The solution is stirred in the container 1 by an agitator 4.

The temperature of the solution in the container 1 should be regulated to within 0.5 during analysis, by means of a thermometer and heating tube 5. The conductimetric electrode 6 consists of a probe, the base of the protective glass casing of which is removed, to prevent cement powder from accumulating inside the electrode. A thermometer (not shown here), connected to a conductimeter 33, is used to adjust results to allow for residual fluctuation in the temperature of the solution. The signal from the conductimeter cell connected with the electrode 6 is sent to an electronic processing unit, which delivers a signal to an analogue computer and/or recording appliance (not shown here).

The appliance shown in FIG. 1 is extremely accurate, as the test results given below shown, for two different crushing operations: the weight obtained by volumetric measurement, using the appliance 7, is found to be uniform.

1st crushing 2nd crushing lst measurement 0.99 g L035 g 2nd measurement 0.99 etc. 0.99 l.0l

l3 measurements were made for the first crushing and 9 for the second. Results were found to be related to the grading of the clinker particles. A variation of approximately 0.0l g was obtained, for a Blaine specific surface-area of 300.

The lime content of clinker was measured by means of the unit shown in FIG. 2, with the appliance 7 set to provide 4 samples of powder hourly. Results were found to be reproducible.

Naturally, the invention is in no way confined in the embodiments described here: many alternative forms are possible, for someone skilled in the art, and depending on the application involved, without any departure from the spirit of the invention.

What is claimed is:

l. A device for measuring out at a filling station successive samples of a powderous substance from a bulk quantity thereof and for delivering said samples at a delivery station located at a distance from said filling station, comprising: a substantially horizontal arm having first and second portions, a calibrated open-ended receptacle mounted on said first portion of said arm; a rotary joint connecting said first arm portion to said second arm portion and permitting rotation of said first arm portion between a first position wherein the open end of said receptacle is upwardly directed and a second position wherein the open end of said receptacle is downwardly directed; a substantially vertical rotary shaft connected to said second portion of said horizontal arm for rotating said arm, a motor driving said vertical shaft for rotating said arm and said receptacle between said filling and delivery stations, means for biasing said first arm portion to said first position, means at said delivery station engageable with said rotary joint for rotating said first arm portion to said second position when said arm is at said delivery station, means for delivering an amount of said powderous substance from said bulk quantity thereof into said receptable when the latter is at said filling station, and means for vibrating said receptacle.

2. The device of claim 1, wherein said vertical shaft and said motor are mounted on a spring-supported base plate, and wherein said vibrating means is a vibrator attached to said base plate.

3. The device of claim 1, which furthermore comprises a scraper-like element arranged on the path of said receptacle between said filling station and said delivery station and adapted to level off the powderous substance in the receptacle by scraping away any excess amount of said substance which may protrude over the open end of said receptacle.

Claims

1. A device for measuring out at a filling station successive samples of a powderous substance from a bulk quantity thereof and for delivering said samples at a delivery station located at a distance from said filling station, comprising: a substantially horizontal arm having first and second portions; a calibrated open-ended receptacle mounted on said first portion of said arm; a rotary joint connecting said first arm portion to said second arm portion and permitting rotation of said first arm portion between a first position wherein the open end of said receptacle is upwardly directed and a second position wherein the open end of said receptacle is downwardly directed; a substantially vertical rotary shaft connected to said second portion of said horizontal arm for rotating said arm, a motor driving said vertical shaft for rotating said arm and said receptacle between said filling and delivery stations, means for biasing said first arm portion to said first position, means at said delivery station engageable with said rotary joint for rotating said first arm portion to said second position when said arm is at said delivery station, means for delivering an amount of said powderous substance from said bulk quantity thereof into said receptable when the latter is at said filling station, and means for vibrating said receptacle.