JPH0788934B2 - Vacuum steam generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention is designed to safely and safely heat an object to be heated at a temperature of 100 ° C or lower.
The present invention relates to a vacuum steam generator that supplies negative pressure steam that is small, lightweight, and always stable for efficient heat treatment.

In various manufacturing factories, heat treatment is widely performed, but such heat treatment often heats the object to be heated at a high temperature of 100 ° C. or higher, and directly uses steam from the boiler as a whole. It is performed by using a heating system of a pressure system.

On the other hand, in a chemical factory or a food factory, there is a case where it is necessary to heat an object to be heated at a relatively low temperature of 100 ° C. or lower due to work safety and product quality.

<Prior Art> Therefore, conventionally, there is a vacuum steam generator as shown in FIG. This is connected to the pressure reducing valve 31 and the condensate discharger 32 via the indirect heating container 30, and the condensate discharger 32 is provided with a bypass pipe 33 which is in continuous communication with the primary side and the secondary side thereof. By guiding the steam supplied to the primary side of the pressure reducing valve 31 by the vacuum pump 34 connected to the secondary side of the condensate discharger 32, the pressure in the indirect heating container 30 can be maintained at a desired pressure reducing system. It is a device that can.

<Problems to be Solved by the Invention> In the above apparatus, the vacuum pump 34 is required as a means for making the pressure after the pressure reducing valve negative. In other words, electric power was required to operate the pump, and its running cost could not be neglected. Further, since the vacuum pump 34 operates at its maximum capacity, the pressure in the indirect heating container 30 becomes a vacuum degree higher than desired. In order to suppress this, by adjusting the flow rate of the bypass pipe 33 of the condensate discharger 32,
The degree of vacuum in the primary side of 32, that is, in the indirect heating container 30 is to be maintained. Therefore, since the system is sucked more than necessary, the steam is always exhausted through the bypass pipe 33 in order to maintain a desired degree of vacuum, and is removed from the vacuum pump 34 to the outside of the system, so that the steam loss becomes very large.

Therefore, a technical problem of the present invention is to obtain a device that does not require a vacuum pump, that is, electric power, and efficiently generates stable negative pressure steam.

<Means for Solving the Problems> The technical means of the present invention taken to solve the above technical problems is an ejector member, a steam separator, a vacuum pressure reducing valve, and an indirect heating container via a circulation path. Condensate outlet pipe that connects the positive pressure steam supply pipe to the primary side of the ejector member and discharges condensed water from the indirect heating container through the circulation path between the indirect heating container and the suction port of the ejector member. The secondary side of the ejector member, the steam separator, the vacuum pressure reducing valve and the indirect heating container form a circulation path with a circulating steam supply pipe, and a condenser discharge device is attached to the steam separator. The vacuum pressure reducing valve is provided with a pressure responsive member that receives a negative pressure on the secondary side of the valve on one surface and causes a pressure setting spring in a tension acting state to act on the other surface.

<Operation> The operation of the above technical means is as follows.

The positive pressure steam supplied to the vacuum pressure reducing valve is supplied from the steam supply pipe through the ejector member and the steam separator. At this time, the jet flow portion of the ejector member is under negative pressure, so that the inside of the indirect heating container connected to the suction port is also generated under negative pressure.
Then, the positive pressure steam is depressurized to the negative pressure steam through the vacuum pressure reducing valve and supplied to the indirect heating container. The steam that has undergone heat exchange in the indirect heating container becomes condensed water, is sucked into the suction port of the ejector member, mixes with the positive pressure steam, and flows to the secondary side of the ejector member. The mixed fluid is separated into steam and condensate by a steam separator, the steam is discharged to a vacuum pressure reducing valve, and the condensate is discharged outside the system by a condensate discharger.

<Effects of the Invention> The specific effects of the present invention are as follows.

Since no vacuum pump is used, no electric power is required, and negative pressure steam can be generated very economically. Moreover, since only the condensate is discharged from the condensate drain to the outside of the system, a system without waste becomes possible.

<Example> An example showing a specific example of the above technical means will be described.
(See FIG. 1) The ejector member 5 is arranged on the steam supply pipes 1, 2, 3 for supplying steam to the indirect heating container 4, and the steam separator 6 is provided between the ejector member 5 and the indirect heating container 4. The vacuum pressure reducing valves 7 are arranged in this order. A condensate discharger 8 is connected to the steam separator 6. The condensate drainer 8 is a steam trap. Next, the condensate outlet pipe 9 for discharging the condensate from the indirect heating container 4
Is connected to the suction port 10 of the ejector member 5. The vacuum pressure reducing valve 7 is a special pressure reducing valve, and its structure is such that a pressure setting spring attached to a pressure responsive member such as a diaphragm in the conventional pressure reducing valve is used in a tensioned state, and the lower surface of the diaphragm is used. Is to open and close the valve by applying a negative pressure on the secondary side, which is the controlled object, to balance both forces. In other words, if the pressure on the secondary side becomes lower than the set pressure, the valve that has been closed until then starts to open and supplies steam on the primary side to the secondary side, and if it becomes higher than the set pressure, it will close again. It acts to suppress the supply of steam.

Positive pressure steam is supplied to the vacuum pressure reducing valve 7 from the steam supply pipes 1 and 2 through the ejector member 5 and the steam separator 6. At this time, since the jet flow portion of the ejector member 5 is under negative pressure, the inside of the indirect heating container 4 connected to the suction port 10 is also created under negative pressure. Then, the positive pressure steam is reduced to negative pressure steam via the vacuum pressure reducing valve 7 and supplied to the indirect heating container 4. The steam that has undergone heat exchange in the indirect heating container 4 becomes condensate and is sucked into the suction port 10 of the ejector member 5 through the condensate outlet pipe 9 and mixed with the positive pressure steam from the steam supply pipe 1 to form an ejector member. 5 to the secondary side. The mixed fluid is separated into steam and condensed water by the steam separator 6, the steam is discharged to the vacuum pressure reducing valve 7 and the condensed water is discharged to the outside of the system by the condensed water discharger 8. Here, the steam supply pipes 1 and 2 are positive pressure steam, and 3 is a negative pressure steam atmosphere.

In the above device, when the load on the indirect heating container 4 increases, the flow rate in the steam supply pipes 1, 2 and 3 also increases, so the suction capacity by the ejector also increases, and the large amount of condensate generated in the indirect heating container 4 Is also well aspirated. On the contrary, when the load is reduced, the action is reverse to the above, and the inside of the indirect heating container is not sucked excessively. As described above, the capacity of the ejector can be automatically adjusted according to the amount of load.

[Brief description of drawings]

FIG. 1 is a piping system diagram of an embodiment showing a specific example of the present invention, and FIG. 2 is a piping system diagram of a conventional vacuum steam generator. 4: Indirect heating container, 5: Ejector member 6: Steam separator, 7: Vacuum pressure reducing valve 8: Condensate discharger

Claims (1)

[Claims] 1. An ejector member, a steam separator, a vacuum pressure reducing valve, and an indirect heating container are sequentially connected through a circulation path, and
A positive pressure steam supply pipe is connected to the primary side of the ejector member, and a circulation path between the indirect heating container and the suction port of the ejector member is formed by a condensate outlet pipe for discharging condensed water from the indirect heating container. A circulation path between the secondary side, the steam separator, the vacuum pressure reducing valve, and the indirect heating container is formed by a circulating steam supply pipe, and a condensate discharger is attached to the steam separator, and the vacuum pressure reducing valve A vacuum vapor generator characterized in that a negative pressure on the secondary side of the valve is received on one surface and a pressure responsive member is provided on the other surface to act a pressure setting spring in a tensioned state.