JPH0536172Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a technology for treating a flared portion of a resin lining of an electromagnetic flowmeter.

PRIOR TECHNOLOGY As is well known, electromagnetic flowmeters are based on Faraday's principle, in which an electromotive force is generated in a conductor moving perpendicularly to a uniform magnetic field in a direction perpendicular to the direction of the magnetic field and the direction of movement. This is a flowmeter with no moving parts that utilizes the law of electromagnetic induction. As shown in Figure 2, a general electromagnetic flowmeter has a space formed by a measuring tube 1, which is a metal tube such as non-magnetic SUS304, and a flange 2 fixed to the end of this measuring tube 1 by welding or the like. A coil 5 and a core 4, which apply a magnetic field perpendicular to the conductive fluid flowing inside the measuring tube 1, are disposed facing each other. Note that an alternating magnetic field is usually applied to this magnetic field in order to remove electrochemical noise. The flow rate signal is output from an electrode 6 that insulates and penetrates the measuring tube in a diametrical direction perpendicular to the magnetic field. Since the electrode comes into contact with the fluid, it should be made of a corrosion-resistant metal suitable for the type of fluid, e.g.
Made of SUS316, Hastelloy, titanium, tantalum, platinum, etc. Further, the measuring tube 1 needs to be electrically insulated from the fluid to be measured, and therefore the inner surface of the measuring tube 1 is lined with an electrically insulating resin having high corrosion resistance such as Teflon. In FIG. 2, this is the lining 3, through which the electrode 6 is fixed in a liquid-tight manner. The lining 3 and the measuring tube 1 are sometimes bonded together using an epoxy adhesive, but epoxy has poor high-temperature adhesive properties.
℃ is the limit of use. In addition, when the temperature reaches 150℃, thermal stress is added, which causes problems such as peeling due to creep. The end portion is heated and expanded to about 200° C. to form a flared portion 31 in contact with the flange end portion 21, and the measuring tube 1 is sandwiched therebetween. In addition, when resin adhesion is not used, a plate-shaped ring (not shown) is brought into contact with it and screwed with a screw or the like.

Problems with the Prior Art As mentioned above, since the conventional flare part 31 is thermoplastically deformed, the flare part 31 and the flange end 2
It does not completely touch 1, but has a small gap. Furthermore, even if an adhesive method is used, the flowmeter will peel off as described above, so when the electromagnetic flowmeter is sandwiched between the pipes, it will be troublesome to align the other centers with the risk of falling. Further, in the case of a plate-shaped ring, there is a problem in that it is expensive because a plate material with a thickness necessary for screwing must be used and corrosion resistance due to contact with liquid must be taken into consideration.

Means for Solving the Problems The present invention is such that the flare portion 31 is pressed against the flange end portion 21 by a ring, and the flare portion end portion and the flange end portion are brought into complete contact with each other by a simple means. This is what I did.

Specific Example FIG. 1 is a diagram for explaining one embodiment of the present invention. In the figure, parts that operate in common with those in FIG. 2 are given the same reference numbers as in FIG. I will omit that explanation. Therefore, in the present invention, a groove 22 is bored on the outer periphery near the flange end 21, and in this groove 22, a thin stainless steel plate having a perpendicular cross section, for example, is formed to cover the outer periphery of the flare portion 31 and the outer periphery of the flange 2. One end of a drawn metal ring 8 is fixed by caulking or other means.

Effects Therefore, according to the present invention, an electromagnetic flowmeter can be installed easily, inexpensively, and safely and accurately using simple means.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of a flowmeter according to the present invention, and FIG. 2 is a diagram showing an example of a conventional flowmeter. 1... Measuring tube, 2... Flange, 3... Lining, 31... Flare part, 8... Metal ring.

Claims (1)

[Scope of utility model registration request] In an electromagnetic flowmeter with an insulating resin lining that integrally covers the end and inner surface of the measuring tube flange, there is a groove on the outer circumferential surface near the flange end, and a groove is formed between the flare part of the resin lining and the flange end. An electromagnetic flowmeter comprising a metal ring that covers the outer periphery and is fixed to the groove by fixing means such as caulking so that the flare part and the flange end are in pressure contact with each other.