JPH0437367B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a powder introduction bellows (hereinafter always referred to as This invention relates to a weighing method in which bellows (called a bellows) does not expand due to the pressure inside the container when powder is introduced and prevent accurate weighing of each container.

(Prior art) A typical example of a tandem type continuous powder supply device is the first one.
As shown in the figure, granular material is supplied from a supply container 1 via an intermediate container 2 to a high-pressure transport container 3, and is discharged into a transport pipe 8 through a transport valve 7.

Each container has a weight measurement detector 9, 1 such as a load cell.
0, and is designed to measure the amount of intake and the amount of discharge.

In the above apparatus, when powder or granules are supplied from the powder supply container 1 to the intermediate container 2, the intermediate container is set at normal pressure and the supply source valve 4a and the supply valve 6a are opened, and the powder is supplied by gravity falling.

In this case, since both the upper and lower containers are at normal pressure, the inside and outside of the bellows 5a are at the same pressure, maintaining the weight insulation function, and changes in the weight of the container 2 are accurately measured.

Next, when supplying the powder from the intermediate container 2 to the high-pressure transport container 3, the pressure in the intermediate container 2 must be set to the same pressure as the pressure in the high-pressure transport container 3 for communication.

This is because the high-pressure transport container 3 must maintain a predetermined pressure at all times since it is used to continuously feed powder and granular material.

Therefore, when both containers are in communication, that is, during a period when both the source valve 4 and the input valve 6 are opened to supply powder from the intermediate container to the high-pressure transport container, the bellows 5 has a pressure equal to the transport pressure. Due to the application of internal pressure, the resulting elongation force apparently reduces the weight of the intermediate container 2, while increasing the gravimetric value of the high-pressure transport container 3.

In reality, during the supply of powder, the weight of the intermediate container 2 decreases over time, and the weight of the high-pressure transport container 3 increases by the amount obtained by subtracting the steady transport discharge amount from the time increase due to the supply. The difference between the weight measurement value (load cell output) and the actual weight becomes large.

Therefore, conventionally, the weight measurement value during the supply period was meaningless.

(Purpose) The purpose of the present invention is to prevent the bellows, which is interposed between two pressure vessels connected vertically in series, from releasing the elongation force that is inevitably generated by the internal pressure applied during the powder supply period to the outside. The present invention provides a method that allows accurate weighing of each container by counterbalancing the extension forces of the counter bellows provided.

(Structure) In the method of the present invention, a powder supply container, an intermediate container, and a high-pressure transport container are connected in series via on-off valves and bellows, respectively, and the intermediate container and the high-pressure transport container are provided with weight measuring means. In the continuous high-pressure transport device, one end of a pair of T-shaped levers whose intermediate portions are rotatably supported by a common pin is mounted on both ends of the bellows between the intermediate container and the high-pressure transport container. and each end of an external bellows is pivotally connected to each end on the other end side of the pair of T-shaped levers, and the external bellows is provided in parallel with the bellows,
During the period when both the containers are in a pressurized state, the external bellows is supplied with enough pressurized gas to cancel out the vertical stretching force due to the internal pressure of the bellows, thereby reducing the weight of the powder in each container. This allows continuous measurement of changes over time during body supply.

(Example) An example of a device that specifically implements the above method is the second example.
1, in which parts corresponding to those in FIG. 1 are designated by the same reference numerals.

Reference numeral 15 denotes an external bellows to which pressurized gas is supplied from the outside, and is positioned parallel to the bellows 5. Both ends 15a and 15b of the external bellows are connected to a pair of T.
The two T-shaped levers 16, 1 are pivotally connected to one end of the type levers 16, 17 by pins 18, 19.
7 intermediate pieces 16a, 17a have a common pivot pin 20
The other ends of the levers are pivotally connected to the upper and lower connecting pipes 21 and 22 of the bellows 5 by pins 23 and 24, respectively.

Since the extension force of the bellows 5 for a certain pressure is known in advance by actual measurement, if the internal pressure of the transport container 3 is known, the extension force (equal in size and opposite direction) at both ends of the bellows during powder supply is also known.

Since the internal pressure of the external bellows versus the outward stretching force is also known, pressurized gas at a pressure capable of generating this stretching force is supplied from a pressure source (not shown).

Therefore, the stretching force generated by the external bellows 15 is
Lever 1 determined by the position of the pin 20 in the intermediate piece
Since the lever action of 6 and 17 acts to cancel the extension force of the bellows 5, if this lever ratio is set appropriately, it is not necessary to use a bellows of the same size as the bellows 5 for the external bellows 15. It is sufficient to have a smaller size, and it is also sufficient that the pressure of the pressurized gas to be supplied is lower than the pressure of the transport container. In this way, it is possible to offset the axial stretching force that inevitably occurs on the bellows 5 due to the pressure inside the container during powder supply.

The two bellows both maintain an internal pressure higher than atmospheric pressure and are balanced at a pressure that cancels out each other's thrust, but both are expandable and retractable bellows,
Moreover, since the pair of T-shaped levers that connect these are connected by only one pin, even if the weight of the container 2 changes, for example, the stretching force due to the internal pressure is balanced. Container of fluctuation 3
It is possible to minimize the influence on
Therefore, even if there is a weight change in either or both of the containers 2, 3, the bellows 5 and the external bellows 15 generate forces in opposite directions, achieving their original function of weight insulation.

(Effects) As described above, the present invention can reduce the internal pressure of the bellows 5 -
Knowing the axial extension force characteristics, it is possible to eliminate the influence of the internal pressure of the bellows 5 on weight measurement by arranging external bellows in parallel via a lever and supplying the required pressurized gas to them. The weight of each cascaded container under pressure can be accurately weighed.

Further, since the external bellows is a system independent of the bellows, it can be designed or selected freely, and it can easily respond to various pressures by changing the lever ratio of the lever.

[Brief explanation of drawings]

FIG. 1 is an overall schematic view of a tandem type continuous high-pressure powder transporting device to which the present invention is applied, and FIG. 2 is a front view of the main parts of an embodiment of the device. Description of symbols 1 is a supply container, 2 is an intermediate container, 3 is a high-pressure transport container, 5 is a bellows, 15 is an external bellows, 16, 17 are T-shaped levers, 18, 19, 2
0, 23, 24 are pins.

Claims (1)

[Claims] 1. A continuous high-pressure transport device in which a powder supply container, an intermediate container, and a high-pressure transport container are connected in series via on-off valves and bellows, and each of the intermediate container and high-pressure transport container is provided with a weight measuring means. ,
At both ends of the bellows between the intermediate container and the high-pressure transport container, one end of a pair of T-shaped levers, the intermediate portion of which is rotatably supported by a common pin, is respectively pivotally mounted. Each end of an external bellows is pivotally connected to each end on the other end side, and the external bellows is provided in parallel with the bellows, and the external bellows is provided in parallel with the bellows during a period when both the containers are in communication and are in a pressurized state. The weight of the tandem container is characterized in that a pressure gas sufficient to suppress elongation due to internal pressure of the bellows is supplied to the bellows, and temporal changes in the respective weights of the intermediate container and the high-pressure transport container are continuously measured. Weighing method.