JPS6064108A - Decompression steam heater - 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 The present invention uses a small, lightweight, and inexpensive device to constantly supply stable reduced pressure steam, thereby reducing the
The present invention relates to a reduced pressure steam heating device that can perform heat treatment safely and efficiently at temperatures below 0°C.

Heat treatment is widely performed in various manufacturing plants. Generally, such heat treatment involves heating the object at 100°
Heating is often done at a relatively high temperature of C or higher, and is carried out using pressurized heating equipment that simply uses steam from the boiler.On the other hand, in chemical factories, etc., there are concerns about work safety. There are cases where the object to be heated must be heated at a relatively low temperature of 100° C. or less due to product quality.

In such cases, conventionally, a pressurized heating device such as the one described above has been applied, and an expensive pressure control mechanism (PIC) and temperature control mechanism (TIC) have been used to effectively reduce a considerable amount of steam loss. Some people have been reluctant to heat it by generating reduced pressure steam or heating it with hot water.

However, the more PIC or TIC is used, the more expensive it becomes, and if a considerable amount of steam loss is accepted, it will inevitably become inefficient in terms of heat energy. In addition, hot water has a small heat capacity and a low film heat transfer coefficient, so heating efficiency is poor, and the heating device is inevitably large and heavy.

The present invention takes into consideration the actual situation of sloping heating, and provides an improved reduced pressure steam heating device that eliminates the conventional drawbacks.

Hereinafter, the configuration of the present invention will be explained in detail based on the drawings.

FIG. 1 is a system diagram showing one embodiment of the present invention, and FIG. 2 is a schematic diagram illustrating a pressure reducing valve in the present invention. A pressure reducing valve 2 and a steam trap 3 are connected to the indirect heating container 1. The steam supplied to the primary side Pl of the pressure reducing valve 2 as shown by the arrow A in the figure is guided by the pressure reducing pump 4 connected to the secondary side S2 of the steam trap 3,
2, the indirect heating container 1, and the steam drag 30, a reduced pressure system is formed between the indirect heating container 1 and the steam drag 30, and the indirect heating container 1 is heated with reduced pressure steam.

In the present invention, the pressure reducing valve 2 has a reversely loaded valve 5 that operates depending on the degree of pressure reduction on its secondary side. That is, a valve 5 is installed in a pressure chamber 7 equipped with a valve 6 capable of vertical movement.
A connecting wall 8 is attached to the wall 8, and a load 9 is applied downward in the drawing. If the degree of pressure reduction on the secondary side P2 is lower in absolute pressure than the desired value (if the system is depressurized too much), the degree of pressure reduction will overcome the load 9 and move the valve 5 upward in the figure, thus increasing the Since the steam passes from the primary side P+ to the secondary side P2,
The degree of pressure reduction on the secondary side P2 increases in absolute pressure, and the degree of pressure reduction in the system is adjusted to a desired value. On the other hand, if the degree of pressure reduction on the secondary side P2 is higher in absolute pressure than the desired value (when it is necessary to further reduce the pressure in the system), the degree of pressure reduction overcomes the load 9,
The load 9 moves the valve 5 downward in the figure, and therefore only a small amount of steam passes from the primary side P1 to the secondary side P2, so the degree of pressure reduction on the secondary side P2 is low in absolute pressure, and the system The degree of pressure reduction is adjusted to a desired value.

Conventionally, the pressure reducing valve originally used in the pressurized system is
In the case shown in the figure, for example, a drawing wall 8a is supported by a spring 11 against a base wall 10, and a load is applied to the drawing wall 8a upward in the drawing due to the pressing force of the spring 11. Therefore, to give an example of its effect, when the pressure on the secondary side P2 is lower than the desired value (when the system pressure is insufficient),
This pressure is overcome by the pressing force of the spring 11, and the pressing force of the spring 11 moves the valve 5a upward, and as a result, as much steam passes from the primary side P1 to the secondary side P2, the secondary Although the pressure on the secondary side increases and the system pressure is adjusted to a desired value, it does not operate if the pressure on the secondary side P2 is below atmospheric pressure.

In short, the pressure reducing valve in the present invention controls the pressure reduction state of the system (absolute pressure, which is lower than atmospheric pressure).
The operating mechanism is completely opposite to that of the conventional pressure reducing valve as shown in the figure, and the valve has a reverse load that operates depending on the degree of pressure reduction on the secondary side.

Further, in the present invention, the steam trap 3 is provided with a bypass that constantly communicates from the downstream side S1 to the secondary side S2. Conventionally, a steam trap originally used in a pressurized system is also provided with a bypass. but,
Such a conventional bypass connects the downstream side and the secondary side intermittently depending on the start of passage of steam, the amount of trapped steam, etc. According to this type of conventional product, as in the present invention, the secondary side S of the steam trap 3
When controlling the depressurized state of the system by guiding steam using the decompression pump 4 connected to the decompression pump 2, stable control is extremely difficult. That is, when controlling the pressure reduction of a system such as the one of the present invention, if a conventional steam trap is used, so-called pulsation occurs, which becomes a serious obstacle to the pressure reduction control of the system.

In the present invention, in order to reliably control system pressure reduction, etc., and therefore stably supply reduced pressure steam to the indirect heating vessel 1, as described above, a pressure reducing valve and a steam trap that are suitably improved for system pressure reduction control, etc. are required. It is important to incorporate.

The following Table 1 shows the results of generating reduced pressure steam using the reduced pressure steam heating device according to the present invention as illustrated in FIG.
This is an example of test results when water at 22° C. was continuously flowed into an indirect heating container equipped with a jacket through which the reduced pressure steam passed. From Table 1, it can be seen that the temperature and pressure on the secondary side of the pressure reducing valve exhibit nearly constant values regardless of fluctuations in the load (water flow rate).

Table 1 (*1: Absolute pressure) According to the present invention described above, it is possible to constantly supply stable reduced pressure steam with a small, lightweight, and inexpensive device.
Therefore, there is an effect that the object to be treated can be safely and efficiently heat-treated at a relatively low temperature, usually 100° C. or lower.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention, FIG. 2 is a schematic diagram illustrating a pressure reducing valve according to the present invention, and FIG. 3 is a schematic diagram illustrating a conventional pressure reducing valve. ■・Indirect heating container, 2...pressure reducing valve, 3-...steam trap, 4...pressure reducing pump, 5.
5a...valve, 6.6a...peripheral wall, 7.7a...pressure chamber,
8.8a...Painting wall, 9...Load, 10...Base wall,
11...Spring, Patent Applicant Chuo Kakoki Co., Ltd. Agent Patent Attorney Hiroshi Iriyama Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1 A pressure reducing valve and a steam trap are connected via an indirect heating container, and the steam supplied to the primary side of the pressure reducing valve is guided by a pressure reducing pump connected to the secondary side of the steam trap, thereby reducing the pressure of the pressure reducing valve. forming a desired reduced pressure system between the secondary side and the indirect heating vessel and the steam trap;
A device for heating an indirect heating container with reduced pressure steam,
The pressure reducing valve has an oppositely loaded valve activated by the degree of pressure reduction on its downstream side, and the steam trap has a bypass in constant communication with its primary and secondary sides, and A reduced pressure steam heating device that constantly supplies stable reduced pressure steam to a heating container.