JPH08170886A - Steam heater - Google Patents

Abstract

PURPOSE: To obtain a steam heater which can heat a material to be heated with steam at 100 deg.C or so uniformly and precisely and can preset a heating temperature at will. CONSTITUTION: A steam-feeding pipe 2 for heating is connected with a heat- exchanger 1. A condensed water storage part 7 is connected with the lower part of the heat-exchanger 1 through a steam trap 4. A down pipe 8 is provided at a side part of the condensed water storage part 7 and the lower end thereof is allowed to communicate within a receiver 11. A vacuum regulating valve 25 is provided at the upper end of the down pipe 8 through a pipe line 23. An opening and closing valve 13 and an air vent 12 are provided at the upper part of the receiver 11. The lower part of the receiver 11 is connected with a suction port 16 for a circulating pump 15 and a discharge port 17 therefor is connected with the lower end of the condensed water storage part 7 through a pipe line 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to heating an object to be heated in a heat exchanger with steam, and particularly, the heating temperature thereof is 100.
The present invention relates to a steam heating device suitable for a relatively low temperature of about C. Specifically, it is used for steam heating of various reaction kettles used for polymerization reaction, food distilling devices, concentrating devices, sterilizing devices, and the like. The object to be heated in these cases is
In most cases, a slight temperature rise causes thermal damage, and it is necessary to maintain the heating temperature with high accuracy.

[0002]

2. Description of the Related Art For example, a conventional steam heating device as shown in FIG. 2 has been used. This heats the heat exchanger 1. The steam supply pipe 2 for heating is connected to the heat exchanger 1, and the falling portion 3 and the steam trap 4 for discharging the condensate generated by the heating are used. The condensate discharge device 5 is configured to heat the object to be heated in the heat exchanger 1 by supplying the steam having a relatively low pressure, that is, a low temperature, from the steam supply pipe 2 to the heat exchanger 1. is there. The steam supplied to the inside of the heat exchanger 1 is condensed by heating to maintain the inside of the heat exchanger 1 at a low pressure below atmospheric pressure.
Steam heating can be performed at a relatively low temperature of 0 ° C. or 100 ° C. or less.

[0003]

In the above-described conventional steam heating device, the non-condensable gas such as air mixed in the steam for heating cannot be removed from the heat exchanger, resulting in uneven heating temperature. There was a problem that the heating temperature could not be maintained with high accuracy.

The heating steam contains some air, but not a little, but in the conventional steam heating apparatus described above, the condensate discharge device 5 is placed in the falling portion 3 and the steam trap 4.
Therefore, the condensate is discharged through the steam trap 4 by the water head pressure accumulated in the falling portion 3, but the non-condensable gas such as air is accumulated in the falling portion 3. There is no such thing and it is not excluded from the outside.

Therefore, the technical problem of the present invention is to eliminate non-condensable gas such as air mixed in the heat exchanger,
An object of the present invention is to provide a steam heating device capable of maintaining a heating temperature with high accuracy.

[0006]

Means for Solving the Problems The technical means of the present invention taken to solve the above technical problems is to form a heating portion in a heat exchanger to connect a steam supply pipe for heating,
In the case where a condensate discharge device for discharging condensed water generated by heating is connected, a condensate reservoir is connected to the condensate discharge device,
A receiver is connected to the condensate reservoir via a falling part having a desired length, and the receiver and the condensate reservoir are communicated with each other via a circulation pump to form the condensate reservoir or A vacuum control valve is attached to the falling part.

[0007]

The operation of the above technical means is as follows.
The heating steam supplied to the heat exchanger condenses by heating the object to be heated and becomes condensed water, which reaches the condensed water reservoir. Non-condensable gas such as air that has flowed down to the condensate reservoir is condensed by forcibly circulating the condensate collected in the condensate reservoir, the falling part and the receiver to the condensate reservoir again. It mixes with the circulation flow of the water and reaches the receiver.

When the amount of gas generated is small, the non-condensable gas in the receiver is stored in the receiver and manually discharged to the outside after the heating process is completed, or the non-condensed gas is discharged. It can be excluded to the outside by installing an air vent or the like, which detects the presence by a float or the like and automatically discharges only the non-condensable gas from the valve port, to the receiver.

By attaching a vacuum degree control valve to the condensate reservoir or the fall portion, the vacuum degree control valve is appropriately operated to adjust the degree of vacuum, so that the fall portion, the condensate reservoir portion, and the inside of the heat exchanger can be controlled. The degree of vacuum can be arbitrarily adjusted, and the temperature of the heating steam can be changed according to the object to be heated.

[0010]

EXAMPLE An example showing a concrete example of the above technical means will be described with reference to FIG. In this embodiment, the same members as those in the conventional technique are designated by the same reference numerals. A steam supply pipe 2 is connected to a heat exchanger 1 as a steam heating device via a pressure adjusting valve 6. A steam trap 4 as a condensate discharge device is attached to the lower part of the heat exchanger 1. A condensate reservoir 7 is connected to the bottom of the steam trap 4. The condensate reservoir portion 7 has a cylindrical cross section, and a falling portion 8 having a predetermined length is attached to the side portion thereof. An opening / closing valve 9 is attached to the upper portion of the falling portion 8 and a lower end 10 thereof is opened in the receiver 11. The receiver 11 is also a cylindrical tank with an air vent 12 and an opening / closing valve 13 attached to the upper part, a makeup water pipe 14 for replenishing water is connected to the lower part, and a suction port 16 of a circulation pump 15 is connected. To do. The outlet 17 of the circulation pump 15 is connected to the lower end of the condensate reservoir 7 via a pipe line 18.

A communication passage 2 between the condensate reservoir 7 and the falling portion 8
A vacuum degree control valve 25 is attached to 2 through a pipe line 23 and an opening / closing valve 24. A well-known self-operated pressure control valve can be used as the vacuum degree control valve 25, and when the pressure on the side of the pipe line 23 becomes lower than the set pressure, the main valve opens and sucks the atmosphere from the side of the inlet 26 to collect the condensed water. By supplying to the part 7 and the falling part 8, the inside of the condensate reservoir part 7 and hence the heat exchanger 1 is maintained at a predetermined vacuum pressure. In this embodiment, as the vacuum degree control valve 25, an example in which a self-powered pressure control valve is used is shown, but other known pressure sensors and other force type pressure control valves may be used in combination.

A pipe 20 and an on-off valve 2 are provided above the condensate reservoir 7.
Attach 1. The open / close valve 21 is opened to bring the inside of the condensate reservoir portion 7 into communication with the atmosphere, and the valve closed state is cut off from the atmosphere.

The set pressure of the vacuum control valve 25 is set so that the pressure in the condensate reservoir 7 is slightly lower than the pressure required in the heat exchanger 1. For example, when a pressure of 360 mm mercury column is required in the heat exchanger 1, the pressure in the condensate reservoir 7 must be lower than that for condensate to flow down. Set to 290 mm mercury column. The length of the falling portion 8 is usually 10 meters.
It is desirable to have a length of about torr.

Next, the operation will be described. If it is necessary to remove the residual air in the condensate reservoir 7 before heating with the heat exchanger 1, first the open / close valve 21 is opened and the circulation pump 15 is driven to receive the receiver. Condensate reservoir 7
After the residual air is removed from the on-off valve 21, the on-off valve 21 is closed and the water flows down into the receiver 11 by its own weight. Is formed and then heated. If it is not necessary to remove residual air before heating, the above operation is not necessary.

The low-pressure heating steam supplied from the steam supply pipe 2 through the pressure adjusting valve 6 is condensed by heating an object to be heated (not shown) in the heat exchanger 1 to become condensed water, and a steam trap is formed. From 4 to the condensate reservoir 7. Condensed water accumulated in the condensate reservoir 7 flows down the falling portion 8 together with a part of the circulating fluid in the receiver 11 supplied from the circulation pump 15 and reaches the inside of the receiver 11. In this case, the non-condensable gas such as air mixed in the heating steam reaches the condensate reservoir 7 together with the condensate, is entrained in the circulating fluid and flows down the falling part 8 to pass through the receiver 11. It collects in the upper part and is discharged to the outside through the air vent 12 or the on-off valve 13.

When the amount of condensed water in the receiver 11 reaches a predetermined amount or more, it is discharged to the outside from a discharge pipe (not shown) or to the outside from a branch pipe (not shown) that branches the discharge port 17 of the circulation pump 15. To do. Further, when the temperature of the circulating fluid reaches a predetermined temperature or higher and may adversely affect the circulation pump 15, cooling water can be supplied from the makeup water pipe 14 to reach the desired temperature.

[0017]

As described above, according to the present invention, the condensate reservoir, the falling portion, the receiver and the circulation pump are sequentially connected to the heat exchanger to forcibly circulate the condensate in the condensate reservoir. By doing so, the non-condensable gas such as air can be made to flow down to the receiver together with the condensate. Therefore, the non-condensable gas in the heat exchanger can be eliminated by the circulation flow, and the heating unevenness in the heat exchanger can be eliminated. Does not occur.

By attaching the vacuum degree control valve, the degree of vacuum in the heat exchanger can be arbitrarily set according to the object to be heated, and the heating temperature can be arbitrarily set even for various kinds of objects to be heated. It can be set to prevent uneven heating.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a steam heating device of the present invention.

FIG. 2 is a configuration diagram showing a conventional example of a steam heating device.

[Explanation of symbols]

 1 heat exchanger 2 steam supply pipe 4 steam trap 7 condensate reservoir 8 falling part 11 receiver 15 circulation pump 25 vacuum control valve

Claims (1)

[Claims] 1. A condensate discharge device in which a heating part is formed in a heat exchanger, a steam supply pipe for heating is connected, and a condensate discharge device for discharging condensed water generated by heating is connected. Connect the condensate reservoir, connect the receiver to the condensate reservoir via a falling part having a desired length, and connect the receiver and the condensate reservoir via a circulation pump. A steam heating device, characterized in that a vacuum control valve is attached to the condensate storage part or the falling part in communication.