JPH0448102A - Vacuum steam generator - Google Patents

Abstract

PURPOSE:To use even if load of a heat exchanger is large and to effectively reuse a large quantity of hot drain water by arranging the vacuum steam outlet of a steam vessel and pressure reducing means through a vacuum steam using unit, and forcibly circulating vacuum steam to the using unit. CONSTITUTION:A vacuum steam generator is composed of a steam vessel 1, a vacuum steam using unit 2 and a vacuum pump 30 as pressure reducing means. Hot drain water fed from a hot drain water inlet tube 3 is stored in the vessel 1, and vacuum steam generated in the vessel 1 is fed to the unit 2 through a vacuum steam outlet 4 to heat a matter to be heated. Condensed water again condensed by heating is sucked to an ejector 8 through a condensed water drain tube 7. Accordingly, the steam is forcibly circulated, and sufficiently heat treated even in the unit 2 having large load to enhance effective utility of the heat.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a vacuum steam generator for treating objects to be heated at a relatively low temperature of about 100° C. or less.

In chemical, food, paper, pulp and textile factories, etc.
Depending on the object to be heated, it is often necessary to process the object at a relatively low temperature of 100° C. or lower.

In addition, since these factories generate a large amount of heated waste water of about 100'C or less, a portion of this heated waste water is used for the above-mentioned treatment.

However, since hot water heating utilizes only the heat contained in hot water, its heat capacity is small, and the film heat transfer coefficient is also small, resulting in low heating efficiency and has not been able to increase production efficiency.

Prior Art Conventionally, a technique as disclosed in Japanese Utility Model Application Laid-Open No. 63-80401 has been used. This connects a hot water inflow pipe and an outlet condensate discharge pipe to the evaporation vessel, connects a steam trap and a vacuum pump to the outlet condensate discharge pipe, and installs a vacuum level control valve that controls the inside of the evaporation vessel to the desired degree of vacuum. The system generates the desired vacuum steam at a pressure below atmospheric pressure, and supplies the vacuum steam through natural circulation to a heat exchanger placed at the top of the evaporation vessel, thereby heating the steam at a relatively low temperature of 100°C or less. be.

Since the heat capacity of steam is larger than that of hot water,
Production efficiency can be improved by increasing heating efficiency.

Problems to be Solved by the Present Invention However, in the above-mentioned conventional technology, there was a problem in that the load on the heat exchanger was limited to small items, and the actual locations in the factory where it was used were also limited. . This is because the heat exchanger is disposed above the evaporation vessel and the generated vacuum steam is supplied to the heat exchanger through natural circulation.

Most of the heated waste water below 100℃ generated in large quantities in the above factories is discarded without being recovered due to low recovery efficiency, and only a small portion is used for hot water heating as mentioned above or It is only used for steam heating.

Therefore, the technical problem of the present invention is to obtain a vacuum steam generator that can reuse a large amount of discarded heated waste water and can be used even if the load on the heat exchanger is large.

Means for solving the problems The technical means of the present invention taken to solve the above problems are as follows:
An evaporation vessel into which heated wastewater flows, a decompression means for maintaining the evaporation vessel at a desired degree of vacuum, and a vacuum steam intake of the evaporation vessel in the evaporator that utilizes the vacuum steam generated by re-evaporation of the heated wastewater. The outlet and pressure reduction means are arranged via a vacuum steam using device.

By arranging the vacuum vapor outlet of the evaporation container and the depressurizing means through the vacuum steam using device, the vacuum vapor generated in the evaporating container is forcibly sucked into the depressurizing means via the vacuum steam using device and circulated.

Effects of the invention By forcibly circulating vacuum steam to steam-using equipment, a large amount of vacuum steam can be supplied even to steam-using equipment with a large load, and a large amount of heated wastewater that was conventionally discarded can be effectively reused. I can do something.

Embodiment An embodiment illustrating a specific example of the above technical means will be described. (
(See FIGS. 1 to 4) First Embodiment (See FIG. 1) A vacuum steam generation device is constituted by an evaporation container 1, a vacuum steam usage device 2, and a vacuum pump 30 as a pressure reducing means. A heated waste water introduction pipe 3 is connected to the evaporation container 1, and a vacuum steam outlet 4 in the upper part is connected to the vacuum steam usage device 2. The vacuum steam using device 2 heats an object to be heated (not shown) by passing vacuum steam in a coil shape inside the device. The object to be heated flows in from the object to be heated 5 and is discharged from the outlet 6 for the object to be heated. The outlet side of the vacuum steam usage device 2 is a condensate discharge pipe 7 connected to a vacuum pump 3.
0 ejector 8. The vacuum pump 30 includes an ejector 8, a water tank 9, a circulation pump 10, and a circulation path 11 connecting these. A nozzle 12 is provided in the ejector 8 and connected to the circulation path 11, and also connects the diffuser 13 and the water tank 9. A cooling water supply pipe 14 for supplying cooling water is connected to a control valve 15 in the water supply tank 9.
At the same time, water level sensors 16 and 17 for detecting the water level in the tank 9 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 are connected by a circulation path 11. A drainage channel 20 is branched between the circulation pump 10 and the nozzle 12 and is provided with a valve 19 that opens and closes according to signals from water level sensors 16 and 17.

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 heated wastewater inside the evaporation container 1 at a predetermined value, and also maintains the inside of the evaporation container 1 at the degree of vacuum generated by the vacuum pump 30 .

Reference numeral 31 is a control unit that issues opening/closing commands to the respective valves based on signals from the water level sensors 16, 17 and the water temperature sensor 18.

The action is as follows.

The heated waste water flowing in from the heated waste water introduction pipe 3 is collected in the evaporation container 1. Since the evaporation container 1 is connected to a vacuum pump 30 through a communication pipe 23, the degree of vacuum generated by the vacuum pump 30 is maintained. Therefore, the heated waste water in the evaporation container 1 is 100'
It reevaporates at relatively low temperatures below C. 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.
It can be set appropriately by controlling wJ with a control valve 15 provided at 4.

The vacuum vapor generated in the evaporation container 1 is transferred to the vacuum vapor outlet 4.
The steam reaches the steam using device 2 and heats the object to be heated. The condensate that has been condensed again by heating is sucked into the ejector 8 through the condensate discharge pipe 7. Therefore, the vacuum steam generated from heated wastewater, which was conventionally often discarded, is forcibly circulated, and even a device using steam with a large load can be sufficiently heated.

The sucked condensate is circulated through the water supply tank 9 and the circulation pump 10, and excess water is removed from the system through the drainage channel 20.

Second Embodiment (See Figure 2) This embodiment has a pressure regulating valve 25 and a vacuum pump 2 in addition to the first embodiment.
6 has been added, and the same members are given the same reference numerals, and a detailed explanation of the vacuum steam generator 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 maintains the supply pressure to the vacuum steam using device 2 at a predetermined value to keep the heating temperature of the object to be heated constant (with high precision). By providing a vacuum pump 26 separate from the vacuum pump 30 in order to maintain the desired degree of vacuum, the operating capacity of the vacuum pump 30 is small, and running costs can be reduced.

Third Embodiment (See Figure 3) This embodiment is the same as the second embodiment by adding an auxiliary steam supply pipe 27 and a steam ejector 28, and the same members as in the above embodiment are given the same reference numerals. , detailed explanation will be omitted.

The vacuum steam generated within the evaporation container 1 is sucked into the steam ejector 28 and mixed with the auxiliary steam supplied from the auxiliary steam supply pipe 27. The mixed steam passes through the pressure regulating valve 25
The vapor is then supplied to the vacuum steam using device 2, where the object to be heated is heat-treated. The heating capacity can be further increased by supplying auxiliary steam.

Fourth embodiment (see Fig. 4) In this embodiment, the pressure control valve 3 is connected to the auxiliary steam supply pipe 27.
4, and a pressure sensor 29 is installed between the steam ejector 28 and the vacuum steam usage device 2.
By operating the pressure control valve 34 via the pressure control valve 5 to control the supply steam pressure, the heating temperature of the object to be heated can be controlled with rough precision.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an embodiment of the vacuum steam generator of the present invention, and FIGS. 2, 3, and 4 are system diagrams showing other embodiments. 1: Evaporation container 2 3: Hot water introduction pipe 4 8: Ejector 12 14: Cooling water supply pipe 23 25: Pressure adjustment valve 27 28: Steam ejector 29 26.30: Vacuum pump 31 34: Pressure control valve Vacuum steam usage device Vacuum Steam outlet nozzle communication pipe Auxiliary steam supply pipe Pressure sensor Control section end) Tao 21 Figure 3

Claims (1)

[Claims] 1. An evaporation container into which heated waste water flows is connected to a decompression means for maintaining the evaporation container at a desired degree of vacuum, and the vacuum steam generated by re-evaporation of the heated waste water is utilized in the evaporation container. A vacuum steam generation device in which a vacuum steam outlet and pressure reduction means are arranged via a vacuum steam usage device.