JP2014029296A - Drain flowmeter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive drain flowmeter.SOLUTION: The drain flowmeter includes: a primary pressure sensor 12 and a secondary pressure sensor 13 attached to an inlet 4 side and an outlet 6 side of a free float type drain trap 19, respectively; a case 20 projectingly fixed to the outside from a valve chamber 3; a rotary plate 22 rotationally attached around a center shaft 21 of the case 20; a float arm 23 whose one end is fixed to the rotary plate 22 and whose other end abuts on the upper end of a float 9 and rotating by moving up and down the float 9 so as to rotate the rotary plate 22; a movable shaft 25 linked to the rotary plate 22 and displaced in a shaft center direction of the case 20 accompanied with the rotation of the rotary plate 22; a permanent magnet 26 built inside the movable shaft 25; a magnetic sensor 27 for detecting a position of the float 9 on the basis of a distance change with the permanent magnet 26 corresponding to the displacement of the permanent magnet 26; and flow rate calculation means 28 for calculating an opening degree of a valve port 7 from the position of the float 9 and for calculating a drain flow amount flowing down the valve port 7 from the primary and secondary pressures.

Description

The present invention relates to a drain flow meter that measures the flow rate of drainage such as condensate and condensed water generated in steam, compressed air, and gas piping systems, and more particularly, a free flow meter that is attached to this piping system and automatically discharges drainage. The present invention relates to a drain flowmeter that measures the flow rate of drain using a float drain trap.

A free float drain trap is a casing in which an inlet, a valve chamber, and an outlet are formed, a valve port that communicates the valve chamber and the outlet is provided in the lower portion of the valve chamber, and a float that opens and closes the valve port is arranged in the valve chamber. The float rises and falls according to the amount of drain flowing into the valve chamber, and the drain is discharged outside by adjusting the opening of the valve port. If the flow rate of the drain discharged from this free float drain trap can be measured, for example, the amount of steam used in the steam using device can be known, and data for improving the heating efficiency of the steam using device can be obtained. Measuring is extremely important. A conventional drain flow meter using a free float drain trap is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-356535. This includes a primary pressure detection means and a secondary pressure detection means attached to the inlet side and the outlet side of the free float drain trap, an ultrasonic transceiver attached to the bottom outer surface of the valve chamber of the float drain trap, Position detecting means for detecting the position of the float from the time until the ultrasonic wave radiated upward from the ultrasonic transceiver is reflected by the float and returns, and the opening of the valve port is calculated from the position of the float Opening degree calculating means, and flow rate calculating means for calculating a drain flow rate flowing down the valve opening from the valve opening degree and the primary side and secondary side pressures are provided.

JP 2000-356535 A

Since the conventional drain flow meter detects the position of the float using an ultrasonic transmitter / receiver, there is a problem that the drain flow meter becomes expensive.

Therefore, the problem to be solved by the present invention is to provide an inexpensive drain flow meter.

In order to solve the above problems, a drain flow meter according to the present invention includes a primary side pressure detection unit and a secondary side pressure detection unit attached to an inlet side and an outlet side of a free float type drain trap, and a valve chamber to the outside. A case that protrudes and is fixed, a rotating plate that is rotatably mounted around the central axis of the case, and one end that is fixed to the rotating plate and the other end abuts on the upper end of the float, and rotates and floats due to the float drop. A float arm that rotates the plate, a movable shaft connected to the rotary plate and displaced in the axial direction of the case as the rotary plate rotates, a permanent magnet built in the movable shaft, and a permanent magnet according to the displacement of the permanent magnet A magnetic sensor for detecting the position of the float based on a change in distance from the magnet, an opening degree calculating means for calculating the opening degree of the valve opening from the position of the float, and the valve opening from the valve opening degree and the primary side and secondary side pressure Flow down It is characterized in that it comprises a flow rate calculating means for calculating the Len flow.

According to the present invention, since the position of the float is detected by the magnetic sensor, there is an excellent effect that an inexpensive drain flow meter can be provided.

It is sectional drawing of the drain flowmeter concerning embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to FIG. The casing of the free float type steam trap is formed by a main body 1 and a lid body 2 fastened to the main body 1 by bolts, and has a valve chamber 3 inside. The main body 1 has an inlet 4 and an outlet 6, and the inlet 4 communicates with an upper portion of the valve chamber 3. A valve seat 8 having a valve opening 7 is attached to the lower side wall of the valve chamber 3. The lower part of the valve chamber 3 communicates with the outlet 6 through the valve port 7. A hollow spherical float 9 that opens and closes the valve port 7 is disposed in the valve chamber 3 in a free state.

A pressure sensor 12 as a primary pressure detecting means is connected to the inflow pipe 10 to which the inlet 4 is connected, and a pressure sensor 13 as a secondary pressure detecting means is attached to the outflow pipe 11 connected to the outlet 6. The case 20 is fixed to the casing 1 by screw connection. A rotating plate 22 is rotatably attached to the inner end bifurcated portion 20 a of the case 20 by a central shaft 21. One end of the float arm 23 is fixed to the rotating plate 22 by press fitting, and the other end of the float arm 23 is brought into contact with the upper end of the float 9. The float arm 23 is rotated by the floating and descending of the float 9 to rotate the rotating plate 22. One end bifurcated portion 25 a of the movable shaft 25 is connected to the rotating plate 22 by a connecting shaft 24. The movable shaft 25 is displaced in the axial direction of the case 20 as the rotating plate 22 rotates. A permanent magnet 26 is built in the other end of the movable shaft 25. A magnetic sensor 27 that detects the position of the float 9 is attached to the case 20 based on a change in distance from the permanent magnet 26 according to the displacement of the permanent magnet 26, separated from the permanent magnet 26 by the partition wall 20 b of the case 20. The magnetic sensor 27 is connected to the flow rate calculation means 28. Each of the pressure sensor 12 and the pressure sensor 13 is also connected to the flow rate calculation means 28.

For calculating the flow rate, the flow rate calculation means 28 determines the drain flow rate from the relationship between the opening degree of the valve port 7 and the capacity coefficient Cv, and the relationship between the primary side and secondary side pressure difference ΔP and the capacity coefficient Cv. An expression Q = Cv · (ΔP) 1/2 for calculating Q is stored. The flow rate calculation means 28 calculates the opening degree of the valve port 7 based on the position of the float 9 detected by the magnetic sensor 27 and obtains the capacity coefficient Cv. Further, the pressure difference ΔP between the primary side and the secondary side of the valve port 7 is obtained from the fluid pressure on the inlet 4 side detected by the pressure sensor 12 and the fluid pressure on the outlet 6 side detected by the pressure sensor 13. Then, the flow rate Q flowing down the valve port 7 is calculated from the capacity coefficient Cv and the pressure difference ΔP between the primary side and the secondary side of the valve port 7.

INDUSTRIAL APPLICABILITY The present invention can be used for a drain flow meter that measures the flow rate of drain such as condensate and condensed water generated in steam, compressed air, and a gas piping system.

DESCRIPTION OF SYMBOLS 1 Main body 2 Lid 3 Valve chamber 4 Inlet 6 Outlet 7 Valve port 8 Valve seat 9 Float 12 Primary side pressure sensor 13 Secondary side pressure sensor 20 Case 21 Center axis 22 Rotating plate 23 Float arm 24 Connection axis 25 Movable axis 26 Permanent Magnet 27 Magnetic sensor 28 Flow rate calculation means

Claims (1)

Primary side pressure detection means and secondary side pressure detection means attached to the inlet and outlet sides of the free float drain trap, a case fixed to the outside protruding from the valve chamber, and rotatable around the central axis of the case A rotating plate attached to the rotating plate, one end fixed to the rotating plate, the other end abutting on the upper end of the float and rotating by floating up and down of the float to rotate the rotating plate, and rotating the rotating plate connected to the rotating plate And a magnetic sensor that detects the position of the float based on a change in the distance between the movable shaft that is displaced in the axial direction of the case, the permanent magnet built in the movable shaft, and the permanent magnet according to the displacement of the permanent magnet, Opening degree calculating means for calculating the opening degree of the valve port from the position of the float, and flow rate calculating means for calculating the drain flow rate flowing down the valve port from the valve opening degree and the primary side and secondary side pressures. Special Drain flow meter to be.

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