JPS6219603A - Tube type electric boiler - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a tube electric boiler.

[Technical Background of the Invention] A tube type electric boiler is a type of electric boiler in which a current is passed directly through a large number of stainless steel tubes (heating tubes), and the Joule heat generated in the tubes heats boiler water in the heating tubes to generate steam. The details are described in, for example, Japanese Patent Application No. 13253/1983.

A system diagram of a conventional tube electric boiler is shown in FIG. 7, an overall view of a heating tube is shown in FIGS. 8 and 9, and a conventional orifice installation method is shown in FIG. 10.

As shown in FIG. 7, water from a water supply source (not shown) passes through a pipe line 9 and reaches the top of the water supply tank 8, and is pumped into the steam separator 2 by a water supply pump 6 installed in a water supply pipe 10. Sent to the liquid phase. The water in the steam separator 2 is sent by a circulating water pump 7 through a circulating water pipe 11 to a constant layer input header 4, and then to a large number of heating pipes 3 and an outlet header.
5 in turn and refluxed to the steam separator 2. The steam in the steam separator 2 is transferred to the steam supply pipe 12
sent via. Three-phase AC power is transmitted to the center of the heating tube 3 from a power supply device 1t1 via a bus bar 13.
The water in the heating tube 3 is directly heated.

An outline of the heating tube 3 is shown in FIG. 8 and FIG. 9. The heating tube is made up of a large number of stainless steel tubes arranged between the inlet header 4 and the outlet header 5, and the number of stainless steel tubes is determined depending on the capacity. For example, generated steam ff125
ton/hour, generated vapor pressure 13+;b/cn+' (1
In a (saturated) boiler, the number of stainless steel tubes is 6.
There are 9 pieces. The heating tube 3 is housed within the casing 22,
The heating tubes 3 are insulated from each other. At the center of the heating tube 3, there is a bus bar 13. Three-phase alternating current passing through the conductive wires 21 in turn is connected via the connecting plate 20, and the stainless steel tube is configured to generate heat directly by Joule heat.

FIG. 10 shows details of the connection between the inlet header 4 and the heating tube 3. An orifice 30 is interposed in the connecting portion to equalize the flow rate of water flowing into each heating tube 3. A copper gasket 31. is attached to a mount 33 provided on the inlet header 4. Orifice 30. Stack the copper gaskets 31 in this order and attach the bag nuts 32.
The heating tube 3 is connected to the mount 33 by.

As described above, conventionally, the orifice 30 had to be attached to each heating tube. Also, the reason why the orifice 30 is mounted with screws rather than flanges is because if flanges are used, the spacing between the heating tubes must be approximately twice this (h), otherwise the 7-range bolts cannot be tightened, and the boiler as a whole will become larger. This is because the flange bolts are difficult to tighten due to the structure of the heating tube.

[Problems with the background technology] In the conventional structure in which the orifice is attached to each heating tube, there are as many seals as there are heating tubes, and this installation requires the use of a screw-in structure for the parts. Therefore, the conventional structure is disadvantageous in terms of seal resistance.

Furthermore, in the conventional structure, when performing orifice maintenance and inspection, it is necessary to disassemble the entire tube to install the orifice, and the heating tube is installed close to the adjacent heating tube. It is difficult to remove and work, and the maintainability of the orifice is poor.

[Objective of the invention] The orifices, which were conventionally attached to one heat tube, are combined into two orifice array plates and installed in the inlet header, thereby eliminating the pressure-resistant seal part of the heating tube and making it possible to remove the orifice from the heating tube. The goal is to eliminate leaks. Another objective is to improve the maintainability of the orifice and to make the entire heating tube more compact.

[Summary of the Invention] A tube comprising a large number of heating tubes, a power supply device that supplies current to the center of the heating tubes, and an outlet header to which one end of the heating tubes is connected with an opening inside. In the tube electric boiler, the inlet header and the heating tube are welded together, and an orifice is attached to the open end of the heating tube in the inlet header.

[Embodiments of the invention] Embodiments of the invention are shown in FIGS. 1 to 6.

Figures 1 and 2 show the installation of the orifice array plate in the inlet header.

Heating tubes 3 are welded to the inlet header 4 in a row at equal intervals, with their tips inserted into the inlet header.

On the other hand, two orifice array plates 40a, 40t) are arranged so that they are located exactly at the tip of the heating tube in the inlet header.
It is installed in pieces. Orifice array plate 40a
, 40b is attached to the metal fitting 42 with bolts, and when removing it, open the inlet header 7 langes 41a, 41b and hand hole 43, remove the bolts, and move the inlet header forward and backward. This can be easily done by

Further, orifices 30 are installed on the orifice array plates 40a, 40b at equal intervals to the heating tubes in accordance with the arrangement of the heating tubes.
By installing the orifice 30 into the inlet header 4, the orifice 30 is set with the center of the hole aligned with the inlet portion of the heating tube 3.

As a result, boiler water flows into the inlet header 4, passes through the orifice 30, and then flows into the heating tube 3.

Figures 3 and 4 show detailed views of the orifice installation section.

A tapered portion 3a is provided at the contact portion between the artificial tip of the heating tube 3 and the orifice 30, and by fixing the orifice array plate 40a to the inlet header 4, there is no tightening force between the heating tube tip and the orifice plate. It has a structure that improves the sealing performance of the contact area.

Also, a gap is provided between the orifice 30 and the orifice array plate 40a, and when installing the orifice array plate, a slight misalignment between the centers of the heating tube 3 and the orifice plate 30 can be avoided between the gap 9 and the tip of the heating tube. This is corrected by the tapered portion 3a.

Further, a guide portion 50 is provided above the orifice array plate 40a for the purpose of reinforcing the orifice array plate 40a in the longitudinal direction and guiding the center position.

Other embodiments are shown in FIGS. 5 and 6.

In the example shown in FIG. 5, orifice 30a is replaced by orifice 40.
It has a structure that is screwed into the aa.

The example shown in FIG. 6 has a structure in which the orifice 30b is screwed in and a gasket 60 is inserted into the sealing portion between the heating tube 3 and the orifice array plate 40ab.

[Effects of the Invention] The electric boiler device according to the present invention has the following effects.

(a) By installing the orifice for each heating tube in the inlet header and eliminating the screw-in orifice attachment section from each heating tube, the reliability of sealing performance is improved to a greater extent.

The structure is such that the lower orifices are installed together on the orifice array plate, so each heating tube is one.

The entire orifice array plate can be taken out at once using the inlet header without disassembling each orifice, improving the maintainability of the orifice.

Since there is no longer an orifice attachment section from the t9 heating tube, there is no longer a need for space for orifice removal work between the heating tubes, which was previously required, and the interval between the heating tubes can be narrowed, making the entire heating tube section more compact.

[Brief explanation of drawings]

FIG. 1 is a side view showing a partially cut away inlet header of the present invention, FIG. 2 is a plan view showing a partially cut away inlet header of the present invention, and FIG. 3 is an orifice of the present invention. The plate mounting is a cutaway plan view showing details of the part, Figure 4 is AA of Figure 3.
5 is a detailed sectional view of the orifice plate mounting section of the present invention, FIG. 6 is a detailed sectional view of the orifice plate mounting section of the present invention, and FIG. 7 is a system diagram of a conventional tube electric boiler. , Figure 8 is a front view of the heating tube of a conventional tube-type electric boiler, Figure 9 is a side view of the heating tube of a conventional tube-type electric boiler, and Figure 10 is a horizontal cross-sectional view of the conventional orifice plate mounting section. be. 1... Power supply device 2... Steam separator 3... Heating tube, 4... Inlet header 5...
Outlet header, 6... Water supply pump 7... Circulation pump, 8... Water supply tank 10... Water supply piping, 11
...Circulating water piping 12...Steam supply piping, 13...
Bus bar 20... Connection plate, 22... Casing 30... Orifice, 31... Packing 32
... Cap nuts 40a, 40b ... Orifice array plate 41a,
41b...Inlet header flange 42...Mounted with metal fittings, 50...Guide portion 60...Patsukin agent Patent attorney Noriyuki Chika Noriyuki Mitsumata Hiroshi No. 4m Fig. 5 Fig. 6 □ Fig. 7 Figure 8 Figure tJ Figure 9

Claims (1)

[Claims] A plurality of heating tubes, a power supply device that supplies current to the center of the heating tubes, an inlet header connected to the heating tubes with one end opened inward, and the other end of the heating tubes opened inward. In the tube electric boiler, the inlet header and the heating tube are welded, and an orifice is attached to the open end of the inlet header of the heating tube. A characteristic tube type electric boiler.