Control method for powder filling hoppers

Abstract

To provide a control method for a powder filling hopper that minimizes powder scattering and also minimizes dust adhesion on the outer surface.SOLUTION: A control method for a powder filling hopper includes: a step to lower a powder filling hopper A, position a protrusion port 3a at the bottom end of a filling port 3 inside a packaging bag 10 so as for the powder to be filled, and position a suction port S3 above the opening at the mouth of the packaging bag; a step to open fully the valve of a valve mechanism and maximize the air suction amount, fill the powder from the filling port into the packaging bag up to the point before a predetermined filling amount while suctioning ambient air from the suction port and suctioning dust emitted in the packaging bag; and a step to narrow the valve of the valve mechanism and fill the powder in small amounts to the extent that the powder from the filling port does not emit dust when the powder is filled up to the point before the predetermined filling amount.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for controlling a powder filling hopper for filling powder. [Background technology]

[0002] Generally, hoppers that are filled with powder generate dust during operation, which can make the working environment around the hopper worse, and the dust can also adhere to the equipment and adversely affect the functioning of the equipment.

[0003] Therefore, such a hopper is provided integrally with a dust collector for collecting dust. For example, as disclosed in Patent Document 1, a damper provided at the lower end of a powder drop pipe receives the fallen powder, and then the damper is opened to drop the powder into a container from the bottom of a funnel-shaped hopper (called a powder chute in Patent Document 1). At this time, to prevent the dust from scattering around, the lower outer periphery of the powder chute is covered with a skirt-shaped tube, and the powder scattered from the container is sucked and removed into the skirt-shaped tube via a suction pipe. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Publication No. 3005326 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, the powder is dropped into a box-shaped container, so there is no problem. However, when filling a plastic film packaging bag with powder, the skirt-shaped tube that sucks up the dust can get in the way. In other words, in the case of the plastic film packaging bag, a rod-shaped spatula must be inserted into the bag opening to maintain the opening. To prevent the spatula from interfering with the skirt-shaped tube, the skirt-shaped tube must be shortened and redesigned. Furthermore, to suck up the dust scattered from the bag opening from above, the tube diameter must be increased and the dust-collecting airflow must be increased.

[0006] However, if the skirt-shaped tube is shortened, powder will adhere to the wide lower outer surface of the funnel-shaped powder chute that guides the dropped powder into the packaging bag. Furthermore, due to the powder's electrostatic float, a large amount of powder will adhere. This large amount of powder will peel off and fall, resulting in an over-weighing. Furthermore, as the powder falls, it may adhere to the opening of the bag, causing poor sealing.

[0007] SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a method for controlling a powder-filled hopper that minimizes powder scattering and also minimizes adhesion of dust to the outer surface. [Means for solving the problem]

[0008] The control method for a powder filling hopper includes a funnel-shaped hopper body having a filling mechanism for filling powder into the upper part of the main body, a filling port for discharging powder into a tapered portion at the bottom of the main body, and a hopper body excluding the tapered portion and the protrusion port of the hopper body. The aforementioned a cover body that covers the filling port from the outside, a gap between the cover body and the tapered portion, and the cover body The aforementioned A method for controlling a powder filling hopper which is provided with an air suction pipe which communicates with an air passage between the filling port and the hopper and which sucks air from a suction port at a lower end of the air passage, and a valve mechanism which is attached to the air suction pipe and which adjusts the amount of air sucked from the suction port, and which fills the hopper while measuring powder with a load cell weighing device, comprising: The steps include: transferring a packaging bag for filling powder to the load cell scale; positioning the protrusion at the lower end of the filling port inside the packaging bag so that the powder can be filled; and setting the suction port at the lower end of the air passage so that it is positioned above the opening of the bag mouth of the packaging bag; fully opening the valve of the valve mechanism for adjusting the intake amount to maximize the intake amount, sucking in outside air from the suction port and sucking in dust generated inside the packaging bag while air is being sucked into the packaging bag. The aforementioned A step of filling powder through a filling port up to just before a planned filling amount; When the weighing scale of the load cell measures that the powder has been filled up to just before the planned filling amount, the outside air is sucked in from the suction port so as not to affect the weight detection of the weighing scale of the load cell. The valve of the valve mechanism is closed. At the same time, the output of the auger is reduced, and the load cell measures the powder until it reaches the planned filling amount. From the filling port Fill the powder in small amounts, and a step of filling the powder up to a predetermined filling amount. [Effects of the Invention]

[0009] The control method for a powder filling hopper of the present invention has the above-mentioned configuration, and when the powder is filled up to just short of the planned filling amount and then weighed as it is filled into a packaging bag, by narrowing the valve of the valve mechanism and filling the powder little by little from the filling port up to the planned filling amount, the influence of wind caused by the suction of dust from the suction port is reduced, and the weight detection of the weighing device is less affected. [Brief explanation of the drawings]

[0010] [Figure 1] Front view of the powder filling hopper of the present invention [Figure 2] Side view of the powder filling hopper of the present invention [Figure 3] 1 is a plan view of a powder filling hopper according to the present invention; [Figure 4] Cross-sectional view of the main part of the suction pipe of the powder filling hopper of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Next, an embodiment of the present invention will be described. The powder filling hopper A of the present invention is equipped with a filling mechanism (e.g., an auger) B for filling powder into the upper part of the main body 1, a funnel-shaped hopper body 4 with a filling port 3 for discharging powder into a tapered section 2 at the bottom of the main body 1, a cover body 5 that covers the tapered section 2 and the filling port 3 of the hopper body 4 from the outside, forming a gap S1 between the tapered section 2 and the cover body 5, and a narrow air passage S2 that communicates with the gap S1 between the cover body 5 and the tapered section 2, and a protrusion port 3a of the filling port 3 protruding from the bottom, and an air suction pipe 6 that communicates with the gap S1 between the cover body 5 and the tapered section 2 and the air passage S2 between the cover body 5 and the filling port 3, and sucks air from a suction port S3 at the lower end of the air passage S2.

[0012] The main body 1 of the hopper body 4 is cylindrical, and an auger B, which is a filling mechanism, is attached to the top plate. The auger B has a rotating screw inside, not shown, and a receiving tray 7 attached to its lower end. The screw rotates to send the powder downward, and the powder falls from the receiving tray 7 into the hopper body 4. The auger B hangs down to the tapered portion 2 of the hopper body 4.

[0013] A tapered section 2 is provided at the bottom of the main body 1, and a narrow-diameter, cylindrical filling port 3 is provided at the bottom of this tapered section 2. The hopper main body 4 is composed of the main body 1, tapered section 2, and filling port 3, and has an overall funnel shape.

[0014] A cover body 5 covers the tapered portion 2 and filling port 3 from the outside. The tapered portion 2 of the hopper body 4 is covered by a short upper cylinder 51 and an inverted truncated cone-shaped portion 52, and a wide gap S1 with a triangular cross section is opened between the outer surface of the tapered portion 2 and the upper cylinder 51 and inverted truncated cone-shaped portion 52. The outer periphery of the filling port 3, except for the ejection opening 3a, is covered by a cylindrical lower cylinder 53 that is concentric with the filling port 3. Therefore, a narrow air passage S2 is formed between the filling port 3 and the cover body 5, and this air passage S2 communicates with the gap S1.

[0015] An air suction pipe 6 is connected to the gap S1, and the air in the gap S1 is sucked in by a vacuum suction device (not shown). When the air in the gap S1 is sucked in, outside air (air) is sucked in from the suction port S3 at the bottom end of the air passage S2, which communicates with the gap S1, and the generated dust is also sucked in. Because outside air is sucked in from the wide gap S1 through the narrow air passage S2, the suction speed is fast and the suction force is strong.

[0016] As described above, the protruding opening 3a of the filling port 3 protrudes slightly from the lower tube 53 of the cover body 5. When filling powder from the powder filling hopper A, the protruding opening 3a from the lower tube 53 is positioned inside the packaging bag 10, and the suction port S3 at the lower end of the lower tube 53 is positioned above the opening of the bag mouth of the packaging bag 10. Dust generated inside the packaging bag 10 is powerfully sucked through the suction port S3.

[0017] Because the suction port S3 powerfully sucks in dust, less powder adheres to the outer surface of the outlet 3a at the bottom end of the filling port 3, and even if some adherence does occur, the small area of ​​the outlet 3a minimizes the possibility of the adhered material peeling off and falling into the packaging bag 10, thereby minimizing the risk of measuring errors. Moreover, this minimizes the risk of powder adhering to the inner surface of the bag opening, causing the bag opening to be poorly sealed.

[0018] The cover body 5 is detachable from the hopper body 4, and is structured so that after work is completed, a connector (not shown) connecting the cover body 5 to the hopper body 4 can be removed and the cover body 5 can be removed for easy cleaning. A connection part 5A for connecting an air suction pipe 6 is attached integrally to the upper part of the cover body 5 at a symmetrical position, and the air suction pipe 6 is connected to this connection part 5A.

[0019] As shown in Figure 4, a valve mechanism (butterfly valve 9A, actuator 9B) 9 that adjusts the amount of outside air (air) drawn in is provided midway along the suction pipe 6, allowing the amount of air drawn in through the suction port S3 to be adjusted. Reference numeral 9B in Figure 4 denotes an actuator that operates the butterfly valve 9A, and the valve opening of the butterfly valve 9A is controlled by a control device (not shown). Reference numeral 9C denotes a manual operating handle.

[0020] Next, an example of how to use this powder filling hopper A when not measuring will be described. Both sides of the top of the packaging bag 10 are clamped by clamps 11 of the bag feeding and packaging machine. The opening of the packaging bag 10 is opened wide by a spatula 12 just before the filling section of the bag feeding and packaging machine.

[0021] The powder filling hopper A, which is located at the top of the filling section of the bag feeding and packaging machine, is lowered by the lifting mechanism so that the outlet 3a protruding from the lower tube 53 is positioned inside the packaging bag 10, and the suction port S3 at the lower end of the air passage S2 is positioned above the opening of the bag mouth of the packaging bag 10. The diameters of the lower tube 53 of the cover body 5 and the outlet 3a of the filling port 3 are small, so there is no interference with the spatula 12.

[0022] Auger B is operated to start supplying powder from tray 7 to hopper body 4, and at the same time, the valve (butterfly valve 9A) of valve mechanism 9 is fully opened to suck air through air suction pipe 6. The powder dropped into hopper body 4 is then dropped into packaging bag 10 through filling port 3. Dust generated as the powder is dropped is sucked through suction port S3 at the bottom end of cover body 5 and passes through air passage S2, gap S1, and air suction pipe 6 to be collected by a dust collector (not shown). When the screw of auger B reaches a predetermined rotation speed, filling is complete, and the packaging bag 10 filled with powder is transported to the next section.

[0023] Next, we will explain how to control the powder filling hopper A when weighing and filling powder. In the above filling method, the powder is fed while the packaging bag 10 is held by the clamp 11, but when weighing and filling, the packaging bag 10 is transferred from the clamp 11 to a weighing device such as a load cell (not shown) in the filling section of the bag feeder and packaging machine.

[0024] The mouth of the packaging bag 10 that has been transferred to the weighing machine is opened with spatula 12. As in the above-described filling method, powder filling hopper A, which is located at the top of the filling section of the bag feeder and packaging machine, is lowered by the lifting mechanism so that the protruding opening 3a protruding from lower tube 53 is positioned inside the packaging bag 10, and the suction port S3 at the bottom end of lower tube 53 is positioned above the opening of the bag mouth of the packaging bag 10. Once powder filling hopper A is set, spatula 12 is retracted.

[0025] The valve of the valve mechanism 9 that adjusts the amount of intake air is fully opened to maximize the amount of intake air, and the packaging bag 10, which has been transferred to the measuring device, is filled with powder through the filling port 3 up to just short of the planned filling amount. As in the above filling method, the powder fed by drop from the hopper body 4 is fed by drop from the filling port 3 into the packaging bag 10, and the dust generated by the drop feeding is sucked through the suction port S3 at the lower end of the cover body 5, passes through the air passage S2, the gap S1, and the air suction pipe 6, and is collected by the dust collector.

[0026] When the weighing scale measures that the powder has been filled up to just short of the planned filling amount, the valve of the valve mechanism 9 is throttled so that the intake of outside air from the suction port S3 does not affect the weight detection of the weighing scale, and the output of the auger B is throttled, so that the powder is filled from the filling port 3 in small amounts at a time, and the powder is accurately filled up to the planned filling amount.

[0027] When measuring with the weighing scale, the protruding opening 3a of the filling opening 3 is located inside the packaging bag 10, and the suction opening at the bottom of the cover body 5 is located above the opening of the bag mouth of the packaging bag 10, so there is less influence of wind due to suction inside the packaging bag 10. As a result, accurate measurement can be achieved.

[0028] After the powder has been accurately filled into the packaging bag 10, the packaging bag 10 is transferred from the weighing device to the clamp 11 and is transported to the next step. [Industrial Applicability]

[0029] The present invention is widely applicable to powder filling hoppers used when filling packaging bags with powder that generates dust and scatters the dust. [Explanation of symbols]

[0030] A Powder filling hopper B. Filling mechanism (auger) 1 Main body 2 Tapered section 3 Filling port 3a protrusion 4 Hopper body 5 Cover body 5A connection 51 Upper cylinder 52 Inverted truncated cone shaped part 53 Lower tube 6 Air suction tube 7 saucers 9 Valve mechanism 9A butterfly valve 9B Actuator 9C Operating handle 10 packaging bags 11 Clamp 12 Spatula S1 void S2 Air passage S3 suction port

Claims

[Claim 1] a funnel-shaped hopper body having a filling mechanism for filling an upper part of a main body with powder and a filling port for discharging powder into a tapered portion at a lower part of the main body; a cover body for externally covering the filling port excluding the tapered portion and the protrusion of the hopper body; an air suction pipe for connecting a gap between the cover body and the tapered portion with an air passage between the cover body and the filling port and for sucking air from a suction port at a lower end of the air passage; and a valve mechanism attached to the air suction pipe for adjusting the amount of air suctioned from the suction port, wherein the powder is filled while being measured by a load cell scale, the method comprising: transferring a packaging bag for filling powder to the weighing scale of the load cell; a step of setting the protrusion at the lower end of the filling port so as to be positioned inside the packaging bag so that the powder can be filled therein, and the suction port at the lower end of the air passage so as to be positioned above the opening of the bag mouth of the packaging bag; a step of fully opening a valve of a valve mechanism for adjusting the intake amount to maximize the intake amount, sucking outside air through the suction port and filling the packaging bag with powder through the filling port up to just short of a planned filling amount while sucking in dust generated within the packaging bag; a step of filling the powder up to the planned filling amount by gradually increasing the amount of powder from the filling port compared to the step in which the load cell's weighing instrument measures that the powder has been filled up to just before the planned filling amount, by throttling the valve of the valve mechanism and throttling the output of the auger so that the weight detection of the load cell's weighing instrument is not affected by the suction of outside air from the suction port, and filling the powder up to the planned filling amount; A method for controlling a powder filling hopper, comprising:

Images