JP2840909B2 - Steam heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam heating apparatus for efficiently heating an object to be heated with steam at about 100.degree. C. while sucking the inside of a heating vessel with a vacuum pump. In chemical, food, and medical product factories, there are many uses where the object to be heated must be heated at a relatively low temperature of about 100 ° C in order to maintain product quality. Heating has conventionally been performed mostly using hot water. However, since hot water has a small amount of heat and tends to cause uneven heating, and requires relatively large-scale equipment for producing and storing hot water, it has recently been required to use a low-pressure steam at about 100 ° C. Is performed.

[0002]

2. Description of the Related Art An example of conventional low-temperature steam heating is disclosed in, for example, JP-A-64-6603. This means that the suction pressure generated in the ejector section can be arbitrarily controlled by supplying steam depressurized by the pressure reducing valve from the primary side of the indirect heating vessel and controlling the temperature of the fluid passing through the nozzle of the ejector to the secondary side. An ejector-type vacuum pump connected to an ejector-type vacuum pump that can be set, wherein the degree of pressure reduction of the pressure reducing valve and the degree of control of the fluid temperature of the nozzle portion are 100 ° C or less, and even more. Even if it is, it can be heated by steam.

[0003] Further, in this conventional example, the object to be heated is prevented from being heated by superheated steam by reducing the temperature of the steam depressurized by a pressure reducing valve by a decelerator and supplying the same to a heating vessel. It is designed to be heated with steam at a temperature.

[0004]

In the case of the above-mentioned prior art, there is a problem that a nozzle, a header and the like are required to reduce the temperature of the superheated steam, and the apparatus itself becomes large and expensive.

Accordingly, it is an object of the present invention to provide an inexpensive steam heater having a simple structure which does not require a nozzle or a header.

[0006]

Means for Solving the Problems The technical means of the present invention taken to solve the above problems is to arrange a steam supply pipe on the primary side of a heating vessel, and to connect an ejector and a diffuser on the secondary side of the heating vessel. -Ther, tank and circulation pump are sequentially connected, a cooling water supply passage for supplying cooling water to the tank is provided, a cooling water control valve is provided in the passage, and the ejector, the tank and the circulation pump are circulated. A fluid temperature detecting member for detecting the temperature of the fluid is provided, and the cooling water control valve is controlled to open and close by a detection signal from the fluid temperature detecting member, wherein a steam supply pipe is penetrated into the tank. is there.

[0007]

[Function] By penetrating the steam supply pipe into the tank,
The steam supplied to the heating vessel is subjected to heat exchange by the fluid in the tank, that is, the mixed fluid of the saturated temperature drain and the cooling water discharged from the heating vessel, and even if the superheated steam is supplied, the saturation temperature is reached. The temperature is reduced to

[0008]

An embodiment showing a specific example of the above technical means will be described (see FIG. 1). Steam supply pipe 2 for supplying steam to heating vessel 1, ejector 3, diffuser 4, and tank 5
And the circulation pump 6 constitute a steam heating device. The steam supply pipe 2 penetrates the inside of the tank 5 through a control valve 7 for adjusting the supply amount, communicates from below to the upper part of the heating vessel 1, and from the lower part of the heating vessel 1 through a valve 20 and a steam trap 21. And communicate with the ejector 3. The ejector 3 and the diffuser 4 are formed integrally, and the end of the diffuser 4 communicates with the upper part of the tank 5. A circulation path 9 communicating from the lower part of the tank 5 to the suction port 8 of the circulation pump 6 is arranged. The discharge port 10 of the circulation pump 6 communicates with the ejector 3 through the circulation path 11. A temperature sensor 14 is provided at a lower portion of the tank 5 as a fluid temperature detecting means for detecting a fluid temperature in the tank.
Attach. A cooling water supply passage 13 communicates with an upper portion of the tank 5 through a cooling water control valve 12.
A communication pipe 15 capable of communicating the inside with the atmosphere is attached. A branch passage 22 is provided from the circulation passage 11 to serve as a surplus fluid discharge passage in the tank 5. In this case, although not shown, it is preferable to attach a liquid level gauge for detecting the liquid level in the tank 5.

Next, the operation will be described. The steam supplied through the control valve 7 passes through the tank 5 and is supplied to the heating vessel 1 to heat the object to be heated. The steam is deprived of heat by the object to be heated and condensed to form drain. The drain is sucked into the ejector 3 through the steam trap 21 or the valve 20. The sucked drain reaches the tank 5 via the diffuser 4 and is sucked by the circulation pump 6 to circulate through the circulation paths 9 and 11. In the ejector 3, the pressure is reduced to a saturation pressure corresponding to the temperature of the circulating fluid, and the drain generated in the heating vessel 1 is sucked. The temperature of the fluid in the tank 5 is measured by a temperature sensor-14.
By controlling the cooling water control valve 12 in accordance with the detection value at step (1), a desired temperature can be obtained, and the suction force at the ejector 3 can be adjusted.

The steam supplied from the steam supply pipe 2 is generally high pressure generated in a boiler. For example, if the heating vessel 1 is to be heated at a temperature of 100 ° C. or less, the control valve 7 The steam pressure must be reduced to about atmospheric pressure or less. When the high-pressure steam is reduced to a low pressure, the amount of heat held by the steam hardly decreases, so that the steam becomes superheated steam. However, in the present invention, since the temperature of the supply steam is reduced by the mixed fluid of the drain and the cooling water in the tank 5, the superheated steam becomes saturated steam and can uniformly heat the object to be heated. In this embodiment, the fluid in the tank 5 is convected from the upper part to the lower part of the tank by the circulating pump 6, so that the temperature of the superheated steam in the steam supply pipe 2 is reduced more reliably. Become.

[0011]

As described above, according to the present invention, it is possible to easily and inexpensively reduce the temperature of superheated steam simply by penetrating a steam supply pipe into a tank without providing a nozzle or a header. Can be.

[Brief description of the drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating container 2 Steam supply pipe 3 Ejector 4 Diffuser 5 Tank 6 Circulation pump 7 Control valve 12 Cooling water control valve 13 Cooling water supply passage 14 Temperature sensor

Claims (1)

(57) [Claims] 1. A steam supply pipe is arranged on a primary side of a heating vessel, and an ejector, a diffuser, a tank, and a circulation pump are sequentially provided on a secondary side of the heating vessel, and cooling water is supplied to the tank. A cooling water supply passage is provided.A cooling water control valve is provided in the passage. A steam heating apparatus in which the cooling water control valve is controlled to open and close by a signal, wherein the steam supply pipe is penetrated into the tank, and the steam supply pipe exchanges heat in the tank.