JPH0570087B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a pressurized steam drain weir type flowmeter that measures the flow rate of condensate generated in a pressurized steam system. A weir-type flow meter determines the flow rate of liquid by detecting the liquid level on the upstream side of a weir based on the relationship between the liquid level on the upstream side of the weir and the flow rate passing through the weir. In particular, the present invention detects the position of the liquid level with a float, and operates an electric signal converter such as a potentiometer, which is separated from the fluid system by a partition wall, and is connected with a magnetic coupling. It concerns the improvement of the structure for detecting liquid level.

Prior Art The liquid level detection structure used in conventional weir-type flowmeters has a cylindrical partition wall arranged vertically, a float slidably attached to the outside of the partition wall, and an electric meter such as a potentiometer mounted inside the partition wall. The operating rod of the signal converter is inserted, a ring-shaped magnet is fixed to the float, and a cylindrical magnet is fixed to the operating rod, and they are magnetically connected by sandwiching the partition wall.

The float floats on the liquid surface, is guided by a cylindrical partition wall, and is displaced up and down with the liquid level. The magnets fixed to the float and the operating rod are attracted to each other by magnetic force, and as the float is displaced, the operating rod inside the bulkhead is displaced. As a result, the position of the liquid level is extracted as an electrical signal from the electrical signal converter.

Problems to be Solved by the Invention In this case, the magnet fixed to the float and the magnet fixed to the operating rod are magnetically attracted to each other across the partition wall, and are pressed into contact with each other. Therefore, when the float is displaced up and down, sliding friction resistance acts between the float and the bulkhead and between the operating rod and the bulkhead, so the displacement resistance becomes relatively large and the displacement of the float and the operating rod lags behind the liquid level. As a result, hysteresis occurs. For this reason, there is a problem in that the accuracy deteriorates when detecting minute changes in the liquid level, and the accuracy of the flow rate determined from the detected liquid level deteriorates. If the magnetic force of the magnet is weakened, the displacement resistance will be reduced, but the connection between the float and the operating rod will become unstable, so it cannot be made weaker than necessary.

The technical problem of the present invention is to reduce the displacement resistance without weakening the magnetic force of the magnet of the magnetic joint.
The object of the present invention is to improve the accuracy of detecting the liquid level, thereby improving the accuracy of measuring the flow rate.

Means for Solving the Problems The technical means of the present invention taken to solve the above technical problems is to form a measurement chamber, an inlet opening at the upper part of the measurement chamber, and an outlet in a casing, and A partition member with an opening is placed in the measurement chamber, a cylindrical partition member is placed vertically in the measurement chamber on the upstream side of the partition member, and a float is placed outside the partition member.
It is attached so that it can be freely displaced in the axial direction and rotatably in the circumferential direction, and the float and the operating rod of the electric signal converter are connected by a magnetic joint across the bulkhead, and a vane is provided on the outer surface of the float, and the inlet is connected above the vane. An inverted U-shaped tube is provided with one end opening into the groove, and the other end of the inverted U-shaped tube is arranged so that the incoming liquid from the inverted U-shaped tube hits the blade and rotates the float. This is a weir-type flowmeter for draining pressurized steam, with the opening facing the blade.

Effect The operation of the above technical means is as follows.

The incoming liquid first enters the groove and collects there. and,
When the liquid level reaches a certain level, it is sprayed onto the float's blades through an inverted U-shaped tube, causing the float to rotate.

The float then rolls on the outer peripheral surface of the cylindrical partition wall while maintaining magnetic coupling with the operating rod. Rolling frictional resistance acts between the float, the bulkhead, and the operating rod, the displacement resistance between the float and the operating rod is small, and the magnetic coupling between them is as strong and stable as before.

Therefore, the float and the operating rod are displaced to closely follow minute changes in the liquid level, hysteresis is reduced, and liquid level detection accuracy is improved. This improves flow rate measurement accuracy.

Effect of the invention The present invention produces the following unique effects.

Since rolling frictional resistance is extremely small compared to sliding frictional resistance, the flowmeter of the present invention has a flow rate measurement accuracy that is one order of magnitude better than that of the conventional example.

In the present invention, the float is displaced up and down while rolling around the partition wall, so even if foreign matter such as scale adheres to the outer surface of the partition wall, the displacement of the float is not easily hindered.

The structure is simpler and less prone to failure than using ball bearings to reduce displacement resistance.

Since a predetermined amount of liquid is allowed to flow in through the inverted U-shaped tube, the float can be reliably rotated even if the amount of liquid flowing in is minute.

A device that uses the power of an electric motor or pump to rotate the float or surrounding liquid is expensive, but the present invention uses the water head difference of the inflowing liquid as the power, so it is simple and inexpensive as no separate power is required. It has the advantage of being able to be made.

Embodiment An embodiment illustrating a specific example of the above technical means will be described (see FIG. 1).

A lid 12 is attached to the main body 10 of the casing, and a measurement chamber 14 is formed inside. A cylindrical partition member 16 with a bottom is arranged in the measurement chamber 14 . Partition member 1
6 has a vertically long weir 18 on the side wall and a communication hole 20 above it.
open it. The inner space (upstream side) of the partition member 16 is connected to the inlet 22, and the outer space is connected to the outlet 24 through a rising passage.

A cylindrical partition member 26 is vertically attached to the lid 12 in an airtight manner. A hollow float 28 is arranged around the partition member 26. The float 28 has a guide tube 30 airtightly fixed along the central axis of a spherical shell 29. Therefore, the float 28 is freely displaceable in the axial direction of the partition member and rotatable in the circumferential direction. An annular magnet 32 is attached to the guide tube 30.

Support members 34, 36, 38 are mounted on top of lid 12 and potentiometer 40 is secured. Potentiometer 40 is covered with cap 42. The electric wires and necessary electrical parts housed in this are not shown.
Operation rod 4 of potentio meter 40, omitting explanation
4 extends downward inside the partition member 26, and a cylindrical magnet 46 is attached at a position facing the magnet 32. One of the magnets 32 and 46 may be a magnetic material.

The magnetic joint made up of the magnet 32 and the magnet 46 is the operating rod 4.
Magnetic force is required to support 4 and displace it. A slide ring 48 made of fluororesin is attached below the magnet 46 of the operating rod 44.

The blades 50 are attached to the surface of the spherical shell 29 of the float 28 so as to be arranged in a ring shape on the horizontal line. each feather 5
0 forms a curved surface inclined in the same circumferential direction.

A bank member 52 having an L-shaped cross section is attached above the partition member 16, and an annular groove 54 is formed between it and the inner wall of the main body 10. Then, an inverted U-shaped pipe 56 is attached across the embankment member 52. The uppermost portion of the inverted U-shaped tube 56 is located below the upper end of the bank member 52, and the inner opening of the bank member 52 is located above the blade 50 and below the outer opening of the bank member 52.

Therefore, the inflow liquid entering from the inlet 22 first collects in the annular groove 54. When the amount of inflow is small, it intermittently falls onto the blade 50 through the inverted U-shaped tube 56. If the amount of inflow is large, it passes through the inverted U-shaped tube 56 and falls continuously onto the blade 50. If the amount of inflow is large, in addition to this, the water will flow over the embankment member 52 and flow down around the float.

The float 28 rotates when the falling liquid hits the blades 50, and floats up and down along with the liquid level inside the partition member 16. The displacement of the float 28 is transmitted to the operating rod 44 by a magnetic coupling (magnets 32, 46), and the output signal of the potentiometer 40 changes. The liquid inside the partition member 16 flows out through the weir 18 and is pushed out to the outlet 24 by the pressure on the inlet 22 side. The relationship between the position of the liquid level inside the partition member 16 and the amount flowing out from the weir 18 is measured in advance, and the flow rate is calculated from the output signal value of the potentiometer 40.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a weir type flowmeter according to an embodiment of the present invention. 14: Measurement chamber, 16: Partition member, 18: Weir,
22: Inlet, 24: Outlet, 26: Partition member, 2
8: Float, 32: Magnet, 40: Potentio
Meter, 44: Operating rod, 46: Magnet, 50: Vane, 54: Liquid reservoir annular groove, 56: Inverted U-shaped tube.

Claims (1)

[Claims] 1 Form a measurement chamber with a casing, an inlet opening at the top of the measurement chamber, and an outlet, place a partition member with an open weir inside the measurement chamber, and place a cylindrical partition member in the vertical direction upstream of the partition member. The float was placed in the measurement chamber on the side, and the float was attached to the outside of the bulkhead member so that it could be freely displaced in the axial direction and rotatably in the circumferential direction, and the float and the operating rod of the electric signal converter were connected with the bulkhead with a magnetic coupling. , a blade is provided on the outer surface of the float,
A groove is provided above the blade for the inflowing liquid from the inlet to collect, and an inverted U-shaped tube with one end open in the groove is placed. A weir-type flow meter for draining pressurized steam with the other end of the U-shaped tube opened facing the blade.