JP2916699B2 - Vacuum steam generator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vacuum steam generator for processing an object to be heated at a relatively low temperature of about 100 ° C. or less.

In chemicals, foods, paper pulp, textile factories, and the like, it is often necessary to treat at a relatively low temperature of 100 ° C. or less depending on an object to be heated. In addition, since a large amount of hot wastewater of about 100 ° C. or less is generated in these factories, the above treatment is performed using a part of the hot wastewater.

However, hot water heating uses only sensible heat possessed by hot water, so its heat capacity is small, and its heat transfer coefficient is also small, so its heating efficiency is low and its production efficiency cannot be increased.

2. Description of the Related Art Conventionally, a technique as disclosed in Japanese Utility Model Application Laid-Open No. 63-80401 has been used. In this method, a hot water inflow pipe and an outlet condensate discharge pipe are connected to the evaporation vessel, a steam trap and a vacuum pump are connected to the outlet ascites discharge pipe, and a vacuum control valve is provided to control the inside of the evaporation vessel to a desired degree of vacuum. Thus, by generating a desired vacuum steam below the atmospheric pressure and supplying the vacuum steam to a heat exchanger disposed at the top of the evaporation vessel by natural circulation,
Steam heating at a relatively low temperature of 100 ° C or less.

Since the heat capacity of the steam is larger than that of the hot water, the heating efficiency can be increased and the production efficiency can be improved.

Problems to be Solved by the Present Invention However, in the above-mentioned prior art, there is a problem that the load on the heat exchanger is limited to a small one, and the actual use place in the factory is also limited. This is because the heat exchanger is arranged at the upper part of the evaporating vessel, and the generated vacuum steam is supplied to the heat exchanger by natural circulation.

Most of the hot wastewater of about 100 ° C or less generated in the above factories is discarded without being collected due to low recovery efficiency, and only a small part is used for hot water heating as described above or vacuum It is only used for steam heating.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a vacuum steam generator capable of reusing a large amount of discarded hot waste water and using a heat exchanger having a large load.

Means for solving the problem The technical means of the present invention taken in order to solve the above-mentioned problems, an evaporation vessel into which warm wastewater flows, and a decompression means for maintaining the evaporation vessel at a desired degree of vacuum are connected, In the above-mentioned evaporating container utilizing vacuum steam generated by re-evaporation of hot waste water, a vacuum steam outlet and a pressure reducing means of the evaporating container are arranged via a vacuum steam using device.

In addition, the evaporating vessel is connected to a separately provided depressurizing means via a pipe, or a depressurizing means is further arranged between the evaporating vessel and the apparatus using vacuum steam.

Function By arranging the vacuum steam outlet of the evaporating vessel and the pressure reducing means via the vacuum steam using apparatus, the vacuum steam generated in the evaporation vessel is forcibly sucked and circulated to the pressure reducing means via the vacuum steam using apparatus.

Effect of the Invention By forcibly circulating vacuum steam to the steam-using device, a large amount of vacuum steam can be supplied even to a steam-using device having a large load, and a large amount of warm wastewater that has been conventionally discarded can be effectively reused. be able to.

Embodiment An embodiment showing a specific example of the above technical means will be described.
(See FIGS. 1 to 4) First Embodiment (See FIG. 1) A vacuum steam generator is constituted by an evaporating vessel 1, a vacuum steam using device 2, and a vacuum pump 30 as a pressure reducing means. The hot water drainage pipe 3 is connected to the evaporating vessel 1, and the upper vacuum steam outlet 4 is connected to the vacuum steamer 2. The vacuum steam application device 2 heats an object to be heated (not shown) by passing the vacuum steam inside in a coil shape. The heated object flows into the heated object inlet 5 and is discharged from the heated object outlet 6. The outlet side of the apparatus 2 using the vacuum steam is a condensate discharge pipe 7 and a vacuum pump 30.
Connected to the ejector 8 of the. The vacuum pump 30 includes the ejector 8, the water supply tank 9, the circulation pump 10, and the circulation path 11 connecting these. A nozzle 12 is provided in the ejector 8 to connect to the circulation path 11 and connect the diffuser 13 to the water supply tank 9. A cooling water supply pipe 14 for supplying cooling water is connected to the water supply tank 9 through a control valve 15, and a water level sensor for detecting a water level in the tank 9 is provided.
16, 17 and a water temperature sensor 18 for detecting the water temperature are attached. The lower part of the water supply tank 9 and the circulation pump 10
Connect with 11. A drainage path 20 provided between the circulation pump 10 and the nozzle 12 and provided with a valve 19 that opens and closes based on signals from water level sensors 16 and 17 is branched.

One end of a communication pipe 23 communicating with the inside of the evaporation container 1 is connected to the ejector 8 of the vacuum pump 30. The communication pipe 23 maintains the liquid level of the hot waste water in the evaporation container 1 at a predetermined value, and
The inside is maintained at a degree of vacuum generated by the vacuum pump 30.

Reference numeral 31 denotes a control unit that issues an open / close command to each valve based on signals from the water level sensors 16, 17 and the water temperature sensor 18.

 The operation is as follows.

The hot waste water flowing from the hot waste water introduction pipe 3
Accumulate inside. Since the evaporating vessel 1 is connected to the vacuum pump 30 through the communication pipe 23, the degree of vacuum generated by the vacuum pump 30 is maintained. Therefore, the warm waste water in the evaporation container 1 re-evaporates at a relatively low temperature of 100 ° C. or less. The degree of vacuum generated by the vacuum pump 30 becomes a saturation pressure at the temperature of the fluid passing through the nozzle 12, and can be appropriately set by controlling the fluid temperature with a control valve 15 provided in the cooling water supply pipe 14.

Vacuum steam generated in the evaporation container 1 reaches the steam use device 2 through the vacuum steam outlet 4 to heat the object to be heated. The condensate condensed again by heating is sucked into the ejector 8 through the condensate discharge pipe 7. Therefore, the vacuum steam generated from the warm wastewater which has been frequently discarded is forcibly circulated, so that even a heavy-load steam-using device can be sufficiently heated.

The sucked condensed water circulates through the water supply tank 9 and the circulation pump 10, and excess water is discharged out of the system through the drainage channel 20.

Second Embodiment (see FIG. 2) This embodiment is obtained by adding a vacuum pump 26 provided separately from the pressure regulating valve 25 to the first embodiment. A detailed description of the device will be omitted.

A pressure regulating valve 25 is provided between the vacuum steam outlet 4 and the vacuum steam using device 2. The pressure regulating valve 25 is a device using vacuum steam 2
By maintaining the supply pressure to the heater at a predetermined value, the heating temperature of the object to be heated is maintained more accurately and constantly. Further, in this embodiment, since the vacuum pump 30 is provided separately from the vacuum pump 30 in order to maintain the inside of the evaporating vessel 1 at a desired degree of vacuum, the operating capacity of the vacuum pump 30 is small and the running cost is low. Can be reduced.

Third Embodiment (see FIG. 3) This embodiment is obtained by adding an auxiliary steam supply pipe 27 and a steam ejector 28 as a further pressure reducing means to the second embodiment.
The same members as those in the above embodiment are denoted by the same reference numerals, and detailed description will be omitted.

By the auxiliary steam supplied from the auxiliary steam supply pipe 27, the vacuum steam generated in the evaporation container 1 is sucked by the steam ejector 28 and mixed. The mixed steam is supplied to the vacuum steam using device 2 via the pressure regulating valve 25, and heats the object to be heated. By supplying the auxiliary steam, the heating capacity can be further increased.

Fourth Embodiment (See FIG. 4) In this embodiment, a pressure control valve 34 is connected to the auxiliary steam supply pipe 27.
And a steam ejector as a further decompression means
A pressure sensor 29 is provided between the apparatus 28 and the apparatus 2 using vacuum steam, and the pressure control valve 34 is operated via a pressure controller 35 to control the supply steam pressure, thereby controlling the heating temperature of the object to be heated with higher accuracy. It is like that.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of a vacuum steam generator according to the present invention, and FIGS. 2, 3, and 4 are system diagrams showing another embodiment. 1: Evaporation vessel, 2: Vacuum steam device 3: Hot water inlet pipe, 4: Vacuum steam outlet 8: Ejector, 12: Nozzle 14: Cooling water supply pipe, 23: Communication pipe 25: Pressure regulating valve, 27: Auxiliary Steam supply pipe 28: Steam ejector, 29: Pressure sensor 26, 30: Vacuum pump, 31: Control unit 34: Pressure control valve

Claims (4)

(57) [Claims] An evaporating vessel into which hot waste water flows, and a pressure reducing means for maintaining the evaporating vessel at a desired degree of vacuum are connected, and a vacuum steam generated by re-evaporation of the hot waste water in the evaporating vessel is used. A vacuum steam generator, wherein a vacuum steam outlet and a pressure reducing means of an evaporation container are arranged via a vacuum steam using device. 2. The vacuum steam generator according to claim 1, wherein the inside of the evaporation vessel and a separately provided pressure reducing means are connected via a pipe. 3. The vacuum steam generator according to claim 1, further comprising a pressure reducing means disposed between the evaporating vessel and the apparatus using the vacuum steam. 4. The vacuum system according to claim 1, wherein the inside of the evaporation vessel is connected to a separately provided decompression means via a pipe, and the decompression means is further disposed between the evaporation vessel and the apparatus using the vacuum steam. Steam generator.