FI118214B - Apparatus for gravimetric metering of powdered material from a container - Google Patents

Description

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Apparatus for gravimetric metering of powdered material from a container

The invention relates to an apparatus for gravimetric metering of a powdered substance from a reservoir. Such powdered substances include e.g. various types of mortars and fillers. In practice, these materials are very difficult to flow and do not want to come out of their tank due to gravity and, if they do, their mass flow out is quite uneven due to e.g. the tendency of the material to arch in the outlet part of the container. Such an outflow portion is generally a funnel-shaped lower portion of a cylindrical storage container having a downflow aperture of a substance.

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In order to achieve a smoother and safer flow of material from such a funnel part, Finnish Patent No. 80430 proposes a structure for an outlet funnel in which elements are provided in the inner walls of the bottom cone of the container through which pressurized air can be introduced. These elements may be welded or otherwise fixed plates.

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Thus, the fluid obtained in the fluidized space, fluidized space, has been found to flow from the funnel substantially uniformly and without arching problems. In such previously known designs, the flow is controlled by a control valve, i. E. 20, located in the outlet, which may be, for example, a bypass valve known per se. In this case the valve has * · · ~. a flap corresponding to the cross-section of the orifice rotatable about an axis of rotation about the diameter of the orifice y. With large volumes of material · · '.v • ·, this control valve has been found to work quite satisfactorily.

The 25-way butterfly valve is metered by the opening in the bottom of the tank; ·· ♦ The shut-off rotary butterfly valve opens through its support point (s) and thus: • Allows the material in the tank to flow under gravity to a lower * · · ♦: *** level. This lower level is usually horizontal. The scales used may be continuous • • *; scale for batch or batch dosing. For example, tank scales are suitable for weighing • M • * „..: 30 powders, granules and liquids. Applications include * · such as metallurgical industry, chemical industry, food industry, and j • · t 0 * · -iv building materials industry.

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The problem with known equipment has been to provide sufficient dosing accuracy at the time! claim. The problem is remedied by the apparatus of the invention, which apparatus comprises, in a known manner, a reservoir and a fluid flowing from its outlet, a valve in the flow passage for opening and closing the flow passageway, and , a stopper having a length in the direction of flow of the valve whose sheath surface forms a sliding surface corresponding to the circumferential surface of the flow opening. In accordance with the basic idea of the invention, the sliding surface has at least one groove extending in the flow direction of the valve, having a clearance after the flow opening at each position of the plug in the flow opening which is greater than the corresponding opening of the flow opening. .

Specific embodiments of the invention are included in the appended claims; independent claims.

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The invention will be explained in more detail with reference to the accompanying drawings in which,;

Figure 1 illustrates the apparatus according to the invention as a single application, ζ • ·? Figure 2 shows a more detailed overall view of the apparatus according to the invention. Figure 3 is a detailed operational description of the apparatus according to the invention. one valve used in the k, and i • * 25:

Figure 4 shows a detailed structure of the valve closure of Figure 3.

Fig. 1 schematically shows the lower part of the powder material reservoir 1 which sup- ***. drips downward into an outlet cone with a flow port at the bottom for the drain * * * from the tank. 30 substances. In the embodiment shown in the figure, there is connected an outlet pipe, · · ·, ·· * ', which is further connected to a sloped drain pipe 7. At the lower end of this flow pipe, a substance flow forming the core of the apparatus according to the invention is connected. a device for opening and closing, respectively, flow control, denoted in the figure by general reference 8. The essential parts of this device consist of a valve seat comprising a flow opening 2 and a plug 3 positioned in the flow opening 2.

In the embodiment shown, the stopper 3 is substantially cylindrical and has a certain axial length. The diameter of the plug is so dimensioned that the plug can be moved by sliding clearance in the opening 2. The groove 4 of the plug 3 is provided with a groove 4. The groove 4 begins at or near the top of the plug 10. The opening 2 can be closed by a stopper 3 when it is pressed down. The groove 4 is formed downwardly expandable. The expansion may be implemented in the form of a widening and deepening shape as shown, or in some cases only a downwardly extending groove of a certain depth. The recess 4 of the groove 4 may have a cross-sectional shape, another arcuate shape 15 or a sharp shape such as a V-shape. The groove extends from the recommended to the bottom of the stopper 3, extending in a selected shape. When designing the groove 4, it is essential to note that its open space downward in all open positions of the plug 3 is greater than the opening (primary opening) from the groove above the opening 2, from which the material to be discharged flows into the groove. The downstream flow path across the valve is particularly relevant for powdery materials. Even a slight contraction can cause a collapse of the flow space, and possibly clogging of the material, or at least a substantial disturbance of the flow. In particular, this is the case that is to be emphasized by the materials which must be kept in their flow state by fluidization operations. *** using you.

In the situation shown in Figures 1 and 2, the flow opening 2 of the apparatus 8 is closed with the plug 3 in the lower position and the opening secured by the seal 9. The situation is illustrative- * * ** *; 3, step c) of the accompanying drawing. Lifting the plug in the opening will release groove 4 ·····. 'Upper part above the edge of the opening 2 to allow the flow of material to begin (Fig. * · · * ... · 30 3, step b) as the primary flow opening opens. Depth position of plug in opening 2 | • * ·

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* · * Adjusts for desired flow. The full flow situation even so that the plug releases the entire opening 2. By pressing down the plug accordingly, the flow opening is reduced in a controlled manner while maintaining the primary flow opening shape.

The movement of the plug 3 in the opening 2 may be effected by a suitable actuator 10, via a spindle 11 5. The actuator may be controlled by a stepless motion or by specific steps. The motion stairs may be of constant length, or progressively, regressively changing depending on the need of the equipment. Likewise, the stepless adjustment movement may be executed as acceleration / deceleration depending on the application.

Unlike the embodiment shown in the figures, the stopper 3 can also be implemented as a tubular structure, in the form of a hollow sleeve, deviating from the full material. The groove 4 in the plug is then formed as a slit in the sleeve wall, which widens towards the bottom of the plug.

There may be more grooves 4 in the stopper than the one shown, for example two or use-15 amps placed on opposite sides of the stopper. However, the one-groove plug has certain flow technical advantages in the present embodiment, in which the substance 1 to be dispensed is generally of high fluidity, and maintaining its fluidity state requires precise equipment enabling structures to operate alongside. • · • ·: ** The size of the opening of the flow path of the primary opening is good to be smooth from the parts of the flow path upstream of the drainage primary opening, · ♦ ·

* ··· 20 as in the illustrated embodiment of the spout 7. J

• »1 · '- ·. $ 1 • 1 •« · ** ♦ ·; . In order to provide and maintain the fluid flow state of the substance, the fluidizing devices 5 are generally essential in the lower part of the tank 1, as are the corresponding devices 12 in the flow pipe 7. These devices carry out the aforementioned gaseous medium, such as. blowing into the substance.

• · · ···· ,, • · »* · • · • 1 ·. It is important for the operation of the equipment that the material to be drained • · 3. Ti * · ♦ · »*« · * the flow through the opening of the groove 4 released by the plug 3 is as smooth as possible.

• 1. To achieve and maintain this flow state with heavy fluid materials Λ mm • 1 '··· 1 30, the apparatus includes a fluid inlet duct 13 through which a suitable fluid medium, primarily air, can be blown directly into the fluid 5: 118214 A i before the flow port 2. Along with this flow channel, it is appropriate for many applications to install vibration devices 6 along the flow port 2.

By means of the apparatus according to the invention, the dosing flow from the container 1 is controlled in accordance with various procedures as required. In batch dosing, the equipment enables trouble-free fine-tuning of the flow at the dosing end. On the other hand, the position of the plug 3 in the flow opening 2 may be selected to cause the apparatus to operate with certain metering batches within the optimum fluid flow range. The equipment is also suitable for continuous flow control.

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The stopper 3 may be implemented in a cross-sectional shape which deviates from the cylinder by other forms of cross-section, for example polygonal, without departing from the invention.

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Claims (11)

An apparatus for gravimetric dosing of powdered material from an outlet opening in the lower portion of a container (1), comprising an apparatus located in a flow channel for the outlet opening of the container from the material valve to open and close the flow channel. , which valve comprises a flow opening (2), and a movable / shutter in the opening with sliding back and forth, which is formed by a plug (3) perpendicular to the opening plane perpendicular to the opening plane and a length in the direction of flow of the valve and whose mantle surface forms a sliding surface corresponding to the flow opening (2), can be: ** · "in the drawing thereof, that the sliding surface exhibits at least one spar (4) which extends in the direction of flow of the valve, and whose width after the flow opening in the plug (3), each position in the flow opening is larger than the corresponding opening of the flow opening. : ***: Installation according to claim 1, characterized in that the plug (3) is a pipe and the lock (4) is a slot in the casing surface of the pipe. •. : * ·. Installation according to Claim 1, characterized in that the plug (3) is of late material and that the lock (4) in the flow direction of the valve is deepened towards the interior of the plug (3). Installation according to claim 3, characterized in that the cross-sectional shape of the lock (4) in the plane direction of the flow opening (2) follows a circular path. / * · · · · · · · Installation according to claim 3, characterized in that the lock (4) in the planar direction of the opening has a V-sectional shape. An installation according to any of the preceding claims, characterized in that the opening and closing opening closing of the plug (3) is performed as a linear movement. Plant according to claim 6, characterized in that the linear movement is stepless or stepwise adjustable. f 8. An installation according to claim 6 or 7, characterized in that the linear movement is arranged to coincide with the flow of the material when the outlet opening (2) is closed. _- «al An installation according to claim 1, characterized in that a connection to the valve flow opening (2) is an air supply device (13) for maintaining the fluidity state of the material to be dosed. An installation according to claim 1, characterized in that, in connection with the flow opening (2) of the valve, vibration means (6) are used to maintain the fluidity state of the material to be dosed. in. 11. An installation according to claim 1, characterized in that in the outlet opening of the container (1) is connected a drain pipe (7) provided with the means (12) for conducting air or other media gas to the material to be dosed to maintain and / or achieving its fluidity state. 'i • M * · · »a a a a Ml • · ·« a • a' -'i • '$ aiMt' · Λ- * a a t a »aa. »Aa *» · »'· _ • aa • · f • a • * a • · • a • a # a» a · a a a # a a a · a a a a a a a a a a a aa a a a a a a a a a a a a a a a a a ··., ··? • a a