JPH0717924Y2 - Electric boiler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an electric boiler used for supplying steam obtained by heating canned water with an electric heater to a steam heating device or the like.

[Prior Art] Conventionally, as shown in FIG.
And a lower pipe side 3. A heating pipe 5 and a liquid column pipe 7 are connected between the upper pipe portion 1 and the lower pipe portion 3.
An electric heater 9 such as a sheathed heater or a cartridge heater, which is electrically insulated by a protective tube, is inserted inside the heating tube 5 and the lower tube portion 3.

One end of the electric heater 9 has a sealing member 11 such as a flange.
It is fixed to. The sealing member 11 is fixed by screwing a bolt 17 to a receiving plate 15 connected to the outer peripheral end of a guide tube 13 connected to the lower surface of the lower tube side 3.

Therefore, the lower end opening of the guide tube 13 is sealed by the sealing member 11, and the heat generating portion of the electric heater 9 is inserted from the inside of the lower tube side 3 to the inside of the heating tube 5. The end of the electric heater 9 projects outward from the sealing member 11, and the terminal 19 projects from the tip of the electric heater 9. This terminal 19 is a heating wire (not shown) provided inside the electric heater 9.
It is connected to the.

A supply pipe 21 for supplying steam is connected to the upper pipe side 1. One end of the supply pipe 21 is screwed and fixed to a mounting seat 23 provided on the upper surface of the upper pipe side 1. Further, on the upper surface of the upper pipe side 1, a plurality of water level detection rods are screwed and fixed to the mounting seat 25.
27 is inserted even inside the liquid column tube 7.

A water supply pipe 32 for inflowing the canned water 30 and a discharge pipe 34 for discharging the canned water 30 in the lower canal 3 are connected to the lower canal 3. Mounting seats 36 and 37 are provided on the lower pipe side 3, and a water supply pipe 32 and a discharge pipe 34 are screwed and fixed to these mounting seats 36 and 37, respectively.

The lower pipe 3 is provided with legs 38. By these legs 38, the heating pipe 5, the liquid column pipe 7 and the upper pipe pipe 1 are installed upside down above the lower pipe pipe 3.

In this electric boiler, with the valve (not shown) provided in the middle portion of the discharge pipe 34 closed, the water from the water supply pipe 32 to the inside of the lower pipe portion 3 as shown by the solid arrow in the figure To supply. The canned water 30 is supplied from the inside of the lower pipe portion 3 to the inside of the heating pipe 5 and the liquid column pipe 7.

At this time, when the water level of the canned water 30 rises slightly above the short water level detection rod 27 inside the liquid column tube 7, the water supply stops. This operation is performed by a solenoid valve (not shown) provided on the water supply pipe 32.
Is opened and closed by the water level detection signal of the water level detection rod 27.

Therefore, the water level of the canned water 30 inside the heating pipe 5 is the liquid column pipe 7.
It becomes the same as the water level.

Now, when the electric heater 9 is energized with the on-off valve (not shown) provided in the supply pipe 21 closed,
30 is heated and vapor is stored inside the upper tube portion 1 as shown by the dashed arrow in the figure. When the steam reaches a predetermined pressure inside the upper pipe section 1, the opening / closing valve of the supply pipe 21 is opened to supply the steam to the device or the like.

At this time, when the water level drops, the water level is detected by the water level detection rod 27, and the can water 30 is supplied from the water supply pipe 32 to the inside of the lower pipe side 3.

The drain pipe 34 can discharge the canned water 30 to the outside by opening the valve when the canned water 30 is extracted.

FIG. 6 shows another conventional example of an electric boiler. In this conventional example, the same parts as those in the conventional example shown in FIG.

In this electric boiler, an electric heater 9 such as a sheathed heater is used. Contrary to FIG. 5, the electric heater 9 is provided near the upper tube 1 and inserted into the heating tube 5. The electric heater 9 has a sealing member 11 provided on the guide tube 13 as in FIG.
It is fixed to.

Also in this electric boiler, steam is supplied by the same operation as that of the electric boiler shown in FIG.

[Problems to be Solved by the Invention] However, when electric heater 9 is energized,
When heating the water, the heating portion of the electric heater 9 inside the lower pipe side 3 also generates heat, so the canned water 30 inside the lower pipe side 3 is heated, and the canned water 30 inside the lower pipe side 3 is heated. Convection occurs. As a result, the temperature rises while heating the canned water 30 in the lower pipe section 3, so that the initial time (rise time) until the steam is supplied becomes long, and the start-up characteristics of the electric boiler are not good.

In this electric boiler, the supply of steam is often repeated intermittently. For this purpose, in order to instantly generate steam and keep it at a predetermined pressure, the length L of the heating portion of the electric heater 9 is required and the watt density must be increased.

If the heating tube 5 is designed to have a heating portion only inside the heating tube 5, there is a limit to the heater capacity that can be put in that range, and the heating portion length L is shortened until steam is supplied. Will take longer. For this reason, the user has a hand-held time when using the steam.

As another conventional example, in the electric boiler shown in FIG. 6, a guide pipe 13 is connected to the upper pipe side 1 by welding, and a heating pipe 5 is connected to the upper pipe side 1 and the lower pipe side 3 by welding. Therefore, when the guide tube 13 and the heating tube 5 do not have the same axial center during welding, the tip of the electric heater 9 touches the inner wall of the heating tube 5 and seals with the receiving plate 15. When the member 11 is fixed, there are problems that the electric heater 9 is damaged and the sealed state is deteriorated.

It may be difficult for the electric heater 9 to obtain a large amount of heat, and if a plurality of electric heaters 9 are to be inserted into the heating tube 5, the guide tube 13 and the heating tube 5 should have the same axis. Welding requires considerable skill.

Further, since the steam is supplied from the supply pipe 21 in a state of containing a large amount of water and impurities, it may cause rust in the device or adhere impurities to cause a device failure.

Therefore, an object of the present invention is to provide an electric boiler that prevents convection of canned water inside the lower pipe, enhances steam supply efficiency, removes impurities in the steam, and supplies high-quality steam. To provide.

[Means for Solving the Problems] The electric boiler of the present invention has an upper pipe side connected to a steam supply pipe and a lower pipe side connected to a water supply pipe into which can water flows. A heating pipe is connected between the upper pipe and the lower pipe. An electric heater is inserted inside the heating tube. A heating pipe is provided penetrating the lower pipe side.
A sealing member is provided at the lower end opening of the heating tube. The end of the electric heater is fixed to the sealing member. A can water flow passage is formed in the heating pipe inside the lower pipe.

The electric boiler of the present invention has an upper pipe portion connected to a steam supply pipe and a water supply pipe into which can water flows.

A heating pipe is connected between the upper pipe and the lower pipe. An electric heater is inserted inside the heating tube. A heating tube is provided penetrating the upper tube side. A sealing member is provided at the upper opening of the heating tube. The end of the electric heater is fixed to the sealing member.

A steam flow passage is formed in the heating pipe inside the upper pipe. Inside these electric boilers, near the upper tube, a weir plate is provided to narrow and pass the steam flow flowing toward the opening of the connection portion of the steam supply tube.

[Action] Can water flows into the lower pipe side through the supply pipe and reaches the heating pipe. In this state, the can water is heated by the electric heater inside the heating pipe. When the can water inside the heating pipe is heated, it rises to the upper part of the heating pipe, so that steam is generated at the water level surface of the heating pipe. The steam is kept at a predetermined pressure inside the upper pipe and then flows out from the steam supply pipe.

Since there is a convection prevention part of the heating pipe inside the lower pipe, heating the can water inside the heating pipe without convection with the can water inside the heating pipe and the can water outside the heating pipe. Is done.

That is, since the can water having a narrow volume inside the heating pipe is heated to be steam, the steam is supplied in a short time.

Furthermore, since a weir plate is provided inside the upper pipe side, the steam flowing in the direction of the steam supply pipe is narrowed by the weir plate and passed therethrough, and the steam is applied to the weir plate, so that the squeeze vapor containing water and impurities is prevented. The removed dry steam is supplied from the steam supply pipe.

[Embodiment] FIGS. 1 to 3 show an embodiment of the electric boiler of the present invention. In this embodiment, the same parts as those in FIG.

With reference to FIGS. 1 to 3, this electric boiler has a heating pipe 5 penetrating a lower pipe side 3. A can water flow passage 40a is formed in the heating pipe 5 inside the lower pipe portion 3. The canned water flow passage 40a is provided with a plurality of small holes as shown in the figure to serve as a flow passage for the canned water 30. The upper end of the heating pipe 5 is connected to the upper pipe side 1, and the lower part of the heating pipe 5 projects downward from the lower pipe side 3. A sealing member 11 such as a flange is provided at the lower end of the heating tube 5. This sealing member
An end portion of the electric heater 9 is fixed to 11.

Therefore, the electric heater 9 is provided so as to extend upward from the lower end of the heating tube 5. As shown in FIG. 2, the sealing member 11 is screwed and fixed to a receiving plate 15 connected to the outer periphery of the lower end of the heating tube 5 with a bolt 17.

On the other hand, a dam plate 42 is provided inside the upper pipe section 1. One end of the barrier plate 42 is fixed to the inner wall of the upper pipe portion 1 between the upper end opening of the heating pipe 5 and the connection opening of the steam supply pipe 21.

The dam plate 42 narrows and allows the steam flow flowing toward the connection opening of the steam supply pipe 21 to pass therethrough.

As shown in FIG. 3, the upper pipe side 1 is connected to a water level detecting rod 27 extending to the inside of the liquid column pipe 7, a steam supply pipe 21, a safety valve, and a connecting pipe connecting to a pressure gauge and the like.

In this electric boiler, water is supplied with a valve (not shown) provided in the middle part of the drain pipe 34 and an opening / closing valve (not shown) provided in the middle part of the steam supply pipe 21 being closed. tube
From 32, can water 30 is supplied to the inside of the lower pipe part 3 as shown by the solid arrow in the figure.

At this time, when the water level of the canned water 30 rises slightly above the short water level detection rod 27 inside the liquid column tube 7, the water supply stops. This water supply stop operation is performed by the operation of closing the solenoid valve (not shown) provided in the water supply pipe 32 by the water level detection signal of the water level detection rod 27.

Therefore, the water level of the canned water 30 inside the heating tube 5 becomes the same as the water level of the liquid column tube 5.

Now, when the electric heater 9 is energized with the opening / closing valve of the steam supply pipe 21 and the valve of the drainage pipe 34 closed, the can water 30 inside the heating pipe 5 is heated, and the broken line shown in the figure. As shown by the arrow, steam is stored inside the upper tube portion 1. When the steam reaches a predetermined pressure inside the upper pipe section 1, the opening / closing valve of the steam supply pipe 21 is opened to supply the steam to the device or the like.

At this time, when the water level is lowered, the water level is detected by the water level detection rod 27, and the can water 30 is supplied from the water supply pipe 32 to the inside of the lower pipe side 3 again. When heating canned water 30, heating tube 5
Since the canned water 30 inside is heated, 30
Enters the inside of the heating pipe 5 through the can water flow passage 40a. That is, the canned water 30 inside the lower tube side 3 is at room temperature, and this canned water 30 enters the inside of the heating pipe 5 from the canned water flow passage 40 a of the heating pipe 5. In the heating tube 5 inside the lower tube portion 3, when the canned water 30 is heated inside the heating tube 5 and reaches a temperature slightly higher than room temperature, the inside of the heating tube 5 rises.

At this time, the heating pipe 5 inside the lower pipe side 3 prevents convection caused by a temperature difference between the canned water 30 inside the heating pipe 5 and the canned water 30 outside the heating pipe 5. The convection prevention unit 5a plays the role.

Therefore, the canned water 30 inside the heating pipe 5 is quickly raised without causing convection of the canned water 30 inside the lower pipe side 3. Therefore, the canned water 30 becomes vapor in a short time and is stored inside the upper pipe section 1.

Since the weir plate 42 is provided inside the upper pipe portion 1 while the steam is directed to the opening of the steam supply pipe 21, the closing steam, that is, the vapor containing water droplets and impurities is applied to the weir plate 42 as the upper pipe. Drop it on the inner bottom of No. 1. Therefore, dry steam can be supplied from the steam supply pipe 21.

It should be noted that the water droplets dropped by the dam plate 42 may be dropped inside the liquid column tube 7 as an example.

FIG. 4 shows another embodiment of the electric boiler of the present invention. In this embodiment, the same parts as those shown in FIGS. 1 to 3 are designated by the same reference numerals and the description thereof will be omitted.

With reference to FIG. 4, this electric boiler has a heating tube 5 penetrating the upper tube portion 1. The upper end of the heating pipe 5 projects above the upper pipe side 1. A sealing member 11 is fixed to the upper end opening of the heating tube 5. The end portion of the electric heater 9 is fixed to the sealing member 11, and the electric heater 9 is inserted inside the heating pipe 5. The sealing member 11 is screwed and fixed to the receiving plate 15 fixed to the upper outer periphery of the heating tube 5 by using bolts 17. A steam flow passage 40b is formed in the heating pipe 5 inside the upper pipe portion 1.

The steam passage 40b serves as a steam passage by forming a plurality of small holes, for example. The lower portion of the heating pipe 5 extends inside the lower pipe portion 3. The lower end of the heating pipe 5 becomes a can water flow passage 40c.

The canned water 30 is, as shown in FIG.
The water level of the can 30 enters the insides of the heating pipe 5 and the liquid column pipe 7 and is located above the heating pipe 5 and the liquid column pipe 7.

Inside the lower pipe section 3, the can water 30 enters the inside of the heating pipe 5 through the can water flow passage 40c. Inside the heating pipe 5, the can water 30 heated by the electric heater 9 rises to generate steam at the water level surface. Then, the steam is stored in the upper pipe portion 1 from the steam flow passage 40b of the heating pipe 5. The subsequent steam supply and can water 30 supply are the same as in the electric boiler shown in FIG.

In this electric boiler, the heating pipe 5 inside the lower pipe portion 3 serves as a convection prevention portion 5b. That is, the canned water 30 heated by the electric heater 9 inserted inside the convection preventive portion 5b of the heating tube 5 rises inside the heating tube 5.

At this time, the convection of the canned water 30 inside the lower pipe section 3 and the canned water 30 inside the heating pipe 5 is prevented by the convection prevention unit 40c.

Further, the weir plate 42 provided inside the upper pipe portion 1 plays the same role as the weir plate 42 shown in FIG. Further, in the conventional electric boiler shown in FIG.
However, the convection of the canned water 30 can be prevented even if this heating portion length L is made equal to the heating portion length L of the electric heater 9 of the electric boiler shown in FIGS. 1 and 4.

The electric boilers described in these embodiments can be applied to a multi-tube type electric boiler in which a plurality of heating tubes 5 are connected between the upper pipe side 1 and the lower pipe side 3. In particular, it can also be used as a once-through type electric boiler.

[Effects of the Invention] As described in the above embodiments, according to the electric boiler of the present invention, the heating tube is provided so as to pass through the upper tube side or the lower tube side, and the electric heater is inserted inside the heating tube. ,
Even when there are many electric heaters, the electric heaters can be inserted along the axis of the heating tube. Therefore, the electric boiler can be easily assembled and repaired.

Since the heating pipe serving as a convection prevention unit is provided inside the lower pipe, convection due to the temperature difference of the can water can be prevented, steam can be supplied in a short time, and power consumption is low. The electric heater can prevent convection of canned water even if it has the same length as the heat generating portion of the conventional electric heater.

Furthermore, since the barrier plate is provided near the upper pipe, dry steam can be supplied from the steam supply pipe.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the electric boiler of the present invention,
FIG. 2 is a partial bottom view of FIG. 1, FIG. 3 is a partial top view of FIG. 1, FIG. 4 is a sectional view showing another embodiment of the electric boiler of the present invention, and FIG. FIG. 6 is a sectional view of the electric boiler of FIG. 6, and FIG. 6 is a sectional view showing another conventional electric boiler. 1 ... Upper tube, 3 ... Lower tube, 5 ... Heating tube, 7 ...
Liquid column tube, 9 Electric heater, 11 Sealing member, 13
Guide pipe, 21 …… Steam supply pipe, 32 …… Water supply pipe, 40a …… Can water flow passage, 40b …… Steam flow passage, 42 …… Weir plate.

Claims (3)

[Scope of utility model registration request] 1. A heating pipe connected between an upper pipe side connected to a steam supply pipe and a lower pipe side connected to a water supply pipe for flowing in can water, and an electric heater inserted inside the heating pipe. In the electric boiler including, the heating pipe is provided near the lower pipe, the sealing member sealing the lower end opening of the heating pipe, and the end of the electric heater is fixed to the sealing member. At the same time, the electric boiler is characterized in that a can water flow passage is formed in the heating pipe inside the lower pipe. 2. A heating pipe connected between an upper pipe side connected to a steam supply pipe and a lower pipe side connected to a water supply pipe for flowing in can water, and an electric heater inserted inside the heating pipe. In an electric boiler including, a sealing member is provided near the upper tube so as to penetrate the heating tube, and an upper opening of the heating tube is sealed, and an end portion of the electric heater is fixed to the sealing member. At the same time, a steam flow passage is formed in the heating pipe inside the upper pipe. 3. A weir plate is provided inside the upper pipe for narrowing and passing a steam flow flowing toward an opening of a connecting portion of the steam supply pipe. The described electric boiler.