JPS6155013B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a fluid heating conduit that can omit insulating flanges at the inlet and outlet of the conduit, which are normally required for the conduit, when the conduit is directly energized to generate heat and the fluid passing through the conduit is heated and kept warm. Regarding.

An example of heating and keeping fluid flowing through the pipe by directly applying electricity to the pipe is when transporting materials with high viscosity that are close to solid at room temperature, such as heavy fuel oil or some crude oil, by heating them. Although it is normal to raise the temperature to make a low-viscosity liquid, the pipeline itself may be directly energized to generate heat and keep it warm.

In such a case, at least one of both ends of the pipeline needs an insulating flange, and the pipeline itself must of course be insulated from the ground.

Furthermore, for example, Japanese Patent Application Laid-open No. 56 (1983) regarding electrically heated reactors
As seen in Publication No. 38132, internal and external heating tubes (No.
1 and 2) in the figure are in direct contact with the reactant, and even if the reactant is conductive, it is possible to create a structure that prevents electrical leakage from the heat generating tube, but it is possible to create a structure that prevents electrical leakage from the heating tube. It is not possible to omit the insulating flange (13 in FIG. 1) of the leading conduit.

The above-mentioned insulating flange has no problem when the fluid passing through the pipe is electrically insulating, but it is not effective when it is electrically conductive, and even if it is insulating,
Over time, impurities contained in the fluid often cause dielectric breakdown of the flange.

The purpose of the present invention is not only to completely eliminate the need for insulating flanges in such cases, but also to eliminate the need for electrically conductive fluids, such as metallic liquids such as liquid sodium with a temperature of 100°C or higher, by direct energization. The purpose is to be able to heat and keep warm.

The present invention provides a voltage difference on both sides of the insulating flange,
In other words, the gist is to make the voltage equivalent to the voltage applied to the insulating flange approximately equal to the voltage across the secondary winding by using the secondary winding of the transformer as the conduit through which the fluid to be heated and kept warm is passed. Incidentally, if desired, a tertiary winding is provided in the transformer in addition to the secondary winding, the tertiary winding and the secondary winding are connected in parallel, and a conduit is connected. Part or all of the current flowing through a certain secondary pipe line is shared by the tertiary winding, or another power supply having the same frequency as the AC power supply applied to the transformer is connected in parallel with the secondary winding. Alternatively, the insulating flange can be omitted by connecting the tertiary winding in parallel so that all or part of the current shared by the tertiary winding is shared. .

Let's explain these using drawings. Figure 1 is the same as that shown in the above-mentioned Japanese Patent Application Laid-Open No. 56-38132,
Figure 2 is an abbreviated diagram of a heat generating tube consisting of inner and outer tubes 1 and 2 which is a part of the load pipeline in Figure 1. You can think of it as an abbreviated diagram of the road. Third,
FIG. 4 shows a modification of the load pipeline shown in FIG. The numbers in FIGS. 1 to 4 are the same.

First, in FIG. 1, reference numeral 1 indicates an inner tube serving as a supply channel for the reaction raw material 8, 2 an outer tube, 3 a gap or an insulator for electrically insulating the inner and outer tubes, and 4 an AC power source.

The inner and outer tubes 1 and 2 inserted into the reactor 7 are connected to a power source 4 outside the reactor 7, and the inner end of the reactor is connected airtightly and electrically at 5, and a load heating circuit is connected to the power source 4. It is beginning to form.

The details of the mutual relationship between the inner and outer tubes 1 and 2 and the power source ₄ are given to the above-mentioned Japanese Patent Application Laid-Open No. 56-38132 _. On the other hand, if t ₂ >> S ₂ , there is no danger of electrical leakage even if the reactor 7 is made of steel and the reactor contents 9 are conductive materials, and even if the internal pressure of the reactor is high temperature and high pressure,
The idea was that the insulating portion 3 needs to withstand high temperatures but does not need to withstand high pressures.

However, even if the reaction raw material fluid 8 introduced into the reactor through the inner tube 1 has no electrical conductivity, such as hydrogen gas, the insulating flange 13 is not necessary unless the entire reaction vessel is made of an insulator. Although the temperature in this part is not as high as that in the reactor 7, it must withstand high pressure. Furthermore, if the reaction raw material 8 contains even a small amount of conductive impurity, the insulation performance of the insulating flange 13 will deteriorate over time.

The present invention was undertaken to completely eliminate these problems with the insulating flange 13 and the limitations placed on the reactant raw material 8.

FIG. 5 shows the present invention applied to the reactor shown in FIG. 1, and numbers 1 to 12 have the same meanings as in FIGS. 1 to 4.

In FIG. 5, reference numeral 13' is a transformer, which essentially supplies the voltage necessary for the primary winding 14 connected to the power source 4 and the secondary circuit including the inner and outer tubes 1 and 2 forming the load pipeline. It consists of a secondary winding to be supplied and has a function equivalent to the insulating flange 13 in FIG. 1, and is called an insulating transformer in the present invention. On the contrary, it is constituted by a tube through which the reaction raw material 8 passes. 21 is an iron core.

One of the tube ends serving as two terminals of the secondary winding 15 is connected to the inner tube 1, and the other is the inlet 1 of the reaction raw material fluid 8.
8 and is further airtightly and electrically connected to the inlet 18.
is connected to the outer tube 2 by a conductor 19 to form a secondary circuit, and heat generation is mainly performed by the current 6 passing through the inner and outer tubes 1 and 2. If the tube is made of a material that does not have good electrical conductivity, such as a copper tube, it must be considered that heat will be generated in this part due to pressure and corrosive properties.

By configuring as described above, the insulating flange 13 that was necessary in FIG. Furthermore, it has become possible to heat even corrosive materials.

However, the calorific value W ₁ and W ₂ of the inner and outer tubes 1 and 2, respectively
In order to freely determine the proportion of heat generation W _t in the secondary winding 15, it is necessary to make the materials, diameters, wall thicknesses, etc. of the inner and outer tubes 1, 2 and the secondary winding 15 different. That alone may not be enough.

In the present invention, such W ₁ , W ₂ ,
As one means of making it possible to arbitrarily select the ratio of W _t , a tertiary winding 16 is provided in the isolation transformer 13', the tertiary winding 16 and the secondary winding 15 are connected in parallel, and the load A part or most of the circuit current 6 can also be shared by the tertiary winding. Note that the tertiary winding 16 in FIG. 5 is shown in a simplified manner, and usually takes a form called an outer iron type or an inner iron type.

That is, now let e ₂ , i ₂ , z ₂ , e ₃ , i ₃ , z ₃ be the no-load voltage, shared current, and internal impedance of the secondary winding and tertiary winding, respectively, and let them be vector quantities, then the current 6 is For i, i=i ₂ + i ₃ (1) e ₂ −i ₂ z ₂ = e ₃ −i ₃ z ₃ (2) holds true, but if e ₂ = e 3 then i ₂ / _{i 3 =} z ₃ /z ₂ (3) Therefore, in order to make the current i ₃ shared by the tertiary winding larger than i ₂ , z ₃ should be made as small as possible.

Then, if the current 6 flowing through the inner and outer tubes 1 and 2 is kept constant, i ₂ will become smaller. In this way 2
The heat generation W _t in the next winding 15 can be made as small as possible.

The tertiary winding 16 of the isolation transformer 13' is connected to the transformer 1
3' cannot be made too large for design or economical reasons, or if it cannot be provided at all, another power source 17 having the same frequency as the power source 4 is connected in parallel to the secondary winding 15 to achieve the above purpose. It is also possible. In FIG. 5, the tertiary winding 16 and the separate power supply 17 are connected in parallel to the secondary winding 15, but as described above, various connections are possible.

Now, from the above explanation, the insulating flange 13 in FIG. 1 is completely unnecessary in any part of the load pipeline in FIG. 5, which is an example of the present invention, but as shown in FIG. It is a normal safety measure to ground 20 the inlet 18 of the reaction raw material 8, etc., and the windings of the secondary winding 15 must be insulated from each other with a heat-resistant insulator, but Currently, heat-resistant insulators that are not required include organic insulators that can withstand temperatures of 400°C, and inorganic materials that can withstand temperatures of 1000°C.

Although the present invention has been described above as applied to an electrically heated reaction device, it is of course also applicable to pipeline transportation of conductive substances that require heating and heat retention.

That is, in FIG. 5, there is no reactor 7, so 9, 10, 11, etc. are not considered, and the inner and outer tubes 1, 2 are, in this case, high-temperature pipelines transporting, for example, liquid sodium metal 8. do.

The inner and outer tubes 1 and 2 form a reciprocating circuit, but the inner tube 1
If the liquid sodium metal is heated and kept warm together with the outer tube 2, and the wall thickness _t2 of the outer tube 2 is set to be larger than the skin depth _S2 of the alternating current 6 flowing through it, and more than several times, this load pipe (pipeline), there is no risk of electrical leakage even if it is grounded on any of the outer surfaces of the outer pipe 2. In other words, the outer tube 2 is a skin current heating tube (Institute of Electrical Engineers of Japan).
(Refer to Electrical Engineering Handbook, page 1578, published in 1978)
Since the current 6 flows only through the inner skin of the outer tube 2, there is no risk of electrical leakage from the outer tube 2 or any danger to humans or animals, and at the same time, the liquid sodium metal 8 is transferred from the inlet side 18 to the far outlet side. 5 (or vice versa).Not only the insulating flange but also the outer tube 2 need not be insulated from the ground, and can now be transported.

Of course, in such a case, a heat insulating layer is usually provided on the outside of the outer tube 2.

Furthermore, when an electric wire is used as a return line for the current 6 instead of the outer tube 2, this electric wire must connect both ends 18 and 5 of the conduit, and it goes without saying that the insulator 3 cannot be omitted. be.

Furthermore, the fluid to be heated 8 is liquid sodium metal,
When the liquid metal is molten lead, the secondary winding 1
5. The inner tube 1 can be made of a heat-resistant insulating tube such as ceramic instead of a good conductor metal, and in this case, the liquid metal itself becomes a conductor of the current 6,
Although the insulator 3 can be omitted, the conductors 2 and 19 are provided on the inlet side 18 and outlet side 5 of the heated fluid 8.
It is necessary to electrically connect the conductive fluid to be heated 8 with a parallel power source corresponding to the tertiary winding 16 and the external power source 17, and connect these terminals at appropriate points. Of course, it is necessary to electrically connect to the fluid 8 to be heated.

Just to be sure, when the fluid to be heated 8 is a metallic liquid and the secondary winding 15, inner tube 1, etc. are made of metal, the current 6 flows in a divided manner through the fluid to be heated 8 and the tube wall. Don't forget about the possibility of heat generation in the design.

As explained above, according to the present invention, not only insulating fluids but also conductive liquid metals can be heated or kept warm or transported through pipes without the need for insulating flanges in any part of the flow path. The present invention is extremely useful industrially.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view of a conventional electrically heated reactor, FIGS. 2 to 4 are schematic plan views showing various shapes of the load pipeline of the present invention, and FIG. 5 is a schematic diagram of the electrically heated reactor of the present invention shown in FIG. It is a cross-sectional schematic diagram when applied to. In these figures, the numbers represent: 1: Inner heat generating tube, 2: Outer heat generating tube, 3: Electrical insulator or gap for insulation, 4: AC power supply, 5:
Airtight electrical connection between the inner and outer tubes, 6: Current flowing through the inner and outer tubes, 7: Reactor, 8: Reaction raw material to be heated (fluid), 9: Reactor contents, 10, 11, 12: Connection to the reactor 13: Insulating flange, 13': Insulating transformer, 14: Primary winding at 13', 15: Secondary winding at 13' consisting of a pipe. line, 16: tertiary winding at 13', 17: separate power supply with the same frequency as power supply 4, 1
8: Inlet (or outlet) of reactant 8, 19: Outer tube 2
and 18 connection, 20: Grounding of the outside of reactor 7 and 18 etc., 21: Iron core.

Claims (1)

[Scope of Claims] 1. An isolation transformer comprising a primary winding connected to an external AC power source and a secondary winding configured with a conduit through which a fluid heated on the load side passes; Of the two pipe ends of the wire, a load pipe line through which the fluid passes, which is connected to the outlet (or inlet) side pipe end of the fluid, and the other end of this load pipe line and a pipe line that becomes the secondary winding. Insulation saving that does not require an insulating flange in any part of the fluid flow path, such as the secondary winding or load pipe, which consists of a means for electrically connecting the fluid inlet (or outlet) side pipe end. Flange fluid heating tube device. 2. The isolation transformer includes a primary winding connected to the external power source and a secondary winding configured with a conduit through which fluid is heated on the load side,
2. The fluid heating tube device according to claim 1, further comprising a tertiary winding connected in parallel with the secondary winding. 3. The isolation transformer includes a primary winding connected to the external power source and a secondary winding configured with a conduit through which fluid is heated on the load side,
A first device characterized in that a separate power source having the same frequency as the external power source is connected in parallel with the secondary winding.
Fluid heating tube device as described in . 4. The isolation transformer includes a primary winding connected to the external power source and a secondary winding configured with a conduit through which fluid is heated on the load side,
2. The fluid heating tube device according to claim 1, further comprising a tertiary winding and a separate power source having the same frequency as the external power source, both of which are connected in parallel with the secondary winding. 5 The load pipeline consists of an inner and outer double pipe, the inner pipe passes the fluid to be heated, the outer pipe has a wall thickness greater than the skin depth of the alternating current flowing through it, and the inner and outer pipes are
5. A fluid heating tube device according to any one of claims 1 to 4, characterized in that the tubes are electrically connected on the side opposite to the power source and are mutually insulated in other parts. 6. The liquid metal flowing in the pipe made of heat-resistant insulator is configured to serve as the secondary winding of the insulating transformer, and the liquid metal itself flowing in the load pipe line also serves as a heating current path. 6. A fluid heating tube device according to any one of claims 1 to 5, characterized in that: