JPS6112162B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drain recovery device used for returning condensate generated in steam-using equipment to a boiler.

The applicant first installed a drain reservoir in the water supply passage between the water supply pump and the boiler, introduced condensate into the drain reservoir when water was not being supplied, and then pressurized make-up water into the drain reservoir during the next water supply. We proposed a drain recovery device that is characterized in that the hot water inside is pumped to a boiler or the like. In this case, the injected make-up water is violently injected into the drain reservoir, mixes with internal hot water, and the low-temperature mixed water is sent under pressure to the boiler, resulting in a problem that the heat recovery efficiency is reduced accordingly.

The present invention aims to solve these inconveniences, and aims to provide a drain recovery device that can reduce the mixing of press-in make-up water and hot water in the drain reservoir, and can provide preferential pumping of hot water. .

The drain recovery device according to the present invention forms a drain reservoir with a closed tank, connects the water supply pump and the lower part of the drain reservoir with a press-in side water supply passage with a check valve interposed, and connects the lower part of the drain reservoir or the press-in side water supply passage. A means is provided for spraying and pressurizing make-up water into the opening on the drain side of the drain basin, and a check valve is interposed in the upper part of the drain basin.
Install the water supply passage on the pressure feeding side that connects to the boiler, etc.
The condensate inlet passage with a check valve is connected to the upper part of the drain reservoir, and the outlet passage with an electrically operated on-off valve is connected to the lower part of the drain reservoir, and the on-off valve is closed when the water supply pump is operating. , a means is provided for controlling the operation of the on-off valve so that the valve is opened when the vehicle is stopped.

The operation of the above drain recovery device will be explained. The water pump will be installed to pump up water from the water tank. The pressure-feeding side water supply passage is connected to a pressure-feeding destination such as a boiler. The inlet passage for condensate is usually installed at the point where condensate is generated, such as in steam-using equipment, through a steam trap.
Link. The outflow passage typically connects to the water supply tank to return excess water.

When the water supply pump is stopped, the on-off valve is operated to the open position. In the press-in side water supply passage and the pressure-feeding side water supply passage, the action of check valves arranged in each prevents backflow from the drain reservoir to the water supply pump and from the boiler to the drain reservoir. Thus, condensate enters the condensate sump through the inlet passage, and excess water in the condensate sump is forced out through the outlet passage.

Next, when the water supply pump is operated, the on-off valve is simultaneously operated to the closed position and the outflow passage is closed. Makeup water from the water supply pump pushes open the check valve, passes through the water supply passage on the press-in side, and enters the drain reservoir. Then, the pressure inside the drain reservoir increases and the check valve of the inflow passage is closed, so that condensate cannot flow into the drain reservoir. On the other hand, since the check valve of the water supply passage on the pressure-feeding side is pushed open, the water in the drain reservoir is forced-fed to the boiler or the like.

As before, the operation and stop of the water supply pump is controlled according to the water level of the boiler, etc., and the above operation is repeated to automatically collect condensate and supply water.

Here, water naturally accumulates in the drain reservoir at a higher temperature in the upper part and a lower temperature in the lower part, so when water is supplied, the higher the temperature in the upper part, the faster the water is sent to the boiler etc. through the pressure-side water supply passage. Since the outflow passage is connected to the lower part of the drain reservoir, when the water supply is stopped, the lower temperature water is discharged faster through the outflow passage.

The make-up water that is pumped from the water supply pump is forced into the drain reservoir by the water spraying means, spreading like a piston to fill the drain reservoir, so it hardly mixes with the condensate in the drain reservoir, and the hot water is heated. It is preferentially pumped to boilers, etc.

Therefore, similar to the previously proposed drain recovery device,
High-temperature hot water is pumped to the boiler with priority over cold water, increasing drain recovery efficiency, and the water supply pump only pumps cold water and does not need to pump high-temperature hot water, which prevents cavitation. There's nothing to do.

Further, in the present invention, since the hot water and makeup water are hardly mixed, the heat recovery efficiency is further increased.

Next, a detailed explanation will be given based on the illustrated embodiment.
1 and 2, the make-up water in the water tank 1 is pumped up by the water pump 2, and the water supply passages 3, 3
a, 3b, and is pumped to the boiler 4. The water supply pump 2 is activated when the water level of the boiler 4 falls to a predetermined low water level BL, for example, according to a signal from the liquid level detector 5.
After that, the operation is controlled to operate until the water level rises to a predetermined high water level BH and then stop. The water supply pump 2 may be a conventional boiler water supply pump. Water supply passages 3a, 3b
is made of pipe members, etc. A drain reservoir 6 is provided in the water supply passage 3. A closed container made by welding disk-shaped plates to the openings at both ends of a tube member can be partitioned into upper and lower parts with partition plates, and the lower chamber can be used as a drain reservoir 6 and the upper chamber can be made as an anteroom 7, which will be described later. A pressure inlet 9 at the end of the passage 3a, which is provided with a check valve 8 that only allows flow in the direction shown by the arrow, opens at the center of the bottom wall of the drain reservoir 6, and is a check valve that only allows flow in the direction shown by the arrow. 10
The pressure feeding port 11 at the starting end of the passage 3b is open to the upper end of the drain reservoir 6. The steam generated in the boiler 4 is transported to the steam-using equipment 13 through, for example, a transport pipe 12, where it is condensed and becomes condensate. Condensate is generally introduced from the steam trap 14 into the drain reservoir 6 through inlet passages 15, 15a,
15b. A part of the inflow passage 15 constitutes the above-mentioned anteroom 7. In the waiting room 7, re-evaporated steam accumulates in the upper part and condensed water accumulates in the lower part. The waiting chamber 7 functions as this gas-liquid separation chamber, and also functions as a temporary storage chamber for condensed water during water supply. Of course, the inflow passage 15 may be replaced by a passage with a large diameter. A passage 15b through which condensate accumulated in the waiting chamber 7 is introduced into the drain reservoir 6 is provided with a check valve 16 that allows flow only in the direction of the arrow. When water is supplied, the pressure in the drain reservoir 6 becomes high, and the check valve 16 does not allow flow. The passage 15b is the waiting room 7 and the drain reservoir 6.
The check valve 16 can be easily maintained by providing it on the outer periphery of the check valve 16. The outlet 17 opened at the lower end of the drain reservoir 6 is connected to the outlet passages 18, 18a, 18.
b, 18c and communicates with the water supply tank 1.
The passage 18 is made of a tube member or the like. An electrically operated on-off valve 19 is attached to the passage 18a. This is operated in conjunction with the water supply pump 2, etc., so that the passage 18a is closed when water is supplied and the passage 18a is opened when water is not supplied. A pressure regulating valve 2 is provided in the passage 18b.
0 is attached. This is a well-known primary pressure regulating valve that uses a spring, and it closes when the primary side is below the set pressure, and when the pressure rises higher than that, it opens and allows fluid to pass through, raising the primary side to the set pressure. It functions to maintain the If the set pressure is atmospheric pressure, it goes without saying that the control valve 2
0 is not required. A discharge passage 22 starting from a discharge port 21 in the upper part of the waiting chamber 7 joins the outflow passage 18 between the control valve 20 and the on-off valve 19. Therefore, when the on-off valve 19 is open and water is not being supplied, the pressure in the waiting chamber 7 and the drain reservoir 6 is equalized, and the uppermost part of the outflow passage 18 (passage 18b) is located above the drain reservoir 6, so that the inside of the drain reservoir 6 is Always filled with liquid. Drain reservoir 6
A dispersion plate 23 is attached to the bottom of the drain tank 6 across the drain reservoir 6. The dispersion plate 23 is provided with a large number of pores 24 uniformly distributed as shown in FIG. Therefore, the make-up water press-ined from the injection port 9 spreads out from the pores 24 of the dispersion plate 23 to fill the drain reservoir 6, and flows into the drain reservoir 6 like a piston.
Since the hot water inside is pushed upward, it is difficult to mix the make-up water and hot water, and the pressure feeding port 11 at the upper end of the drain reservoir 6 is
Hot water is preferentially pushed out. The outlet 17 may be located below the distribution plate 23.

Next, the operation will be explained. When the water level of the boiler 4 is at the position shown in the figure, that is, the evaporation has progressed to a predetermined high level 1.
When the water supply reaches the position shown in the figure from 3H, the water supply pump 2 is stopped and the on-off valve 19 is opened. When condensate accumulates in the waiting room 7, the low-temperature water at the bottom of the drain reservoir 6 flows through the outflow passage 18 to the water supply tank 1.
Accordingly, the condensate in the waiting chamber 7 flows down to the drain reservoir 6 and accumulates in the upper part. In this way, the inside of the drain reservoir 6 is gradually replaced with high temperature hot water. During the introduction of such condensate into the drain reservoir 6, when evaporation progresses and the water level in the boiler 4 falls to a predetermined water level BL, the water supply pump 2 is started and the on-off valve 19 is closed. Therefore, makeup water is sent into the drain reservoir 6 from the pressure port 9, spreads through the pores 24 of the distribution plate 23 to fill the entire drain reservoir 6, rises like a piston, and almost mixes with the hot water in the drain reservoir 6. Hot water is preferentially sent to the passage 3b from the pressure feeding port 11 without being mixed again. During this time, the check valve 16 is closed due to the increased pressure in the drain reservoir 6, and the condensate is stored in the anteroom 7. When water is supplied in this way and the water level in the boiler 4 reaches a predetermined high water level again, the water supply pump 2 is stopped,
The on-off valve 19 is opened and the drain reservoir 6 is opened in the same manner as described above.
Condensate is introduced into the boiler 4 and the same operation as described above is repeated to forcefully feed the condensate to the boiler 4.

A similar effect to the dispersion plate 23 can be obtained in another embodiment shown in FIG. That is, a full conical nozzle 30 is provided at the center of the bottom wall of the drain reservoir 6, and the make-up water from the water supply passage 3a is spread to fill the drain reservoir 6 and sprayed upward as shown in the figure.

As is clear from the above description, according to the present invention, the make-up water that is press-injected into the drain reservoir is spread to the full extent of the drain reservoir like a piston using a water spraying means such as a distribution plate or a full conical nozzle. Since the hot water is forced in so as to be forced out, the hot water in the drain reservoir hardly mixes with makeup water and is preferentially sent to the boiler etc., resulting in highly efficient drain recovery.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a drain recovery device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line -
The figure is a schematic diagram showing only the different parts from FIG. 1 of a drain recovery device of another embodiment. 2 is a water supply pump, 3 is a water supply passage, 4 is a boiler,
6 is a drain reservoir, 7 is a waiting room, 15 is an inflow passage, 18
19 is an electrically operated on-off valve, 20 is a pressure regulating valve, 23 is a dispersion plate, and 30 is a full conical nozzle.

Claims (1)

[Claims] 1. Form a drain reservoir in a sealed tank, connect the water supply pump and the lower part of the drain reservoir with a press-in side water supply passage with a check valve interposed, and supply water to the lower part of the drain reservoir or the drain reservoir side opening of the press-in side water supply passage. A means for sprinkling and pressurizing water is provided, and a water supply passage on the pressure side connected to a pressure destination such as a boiler with a check valve interposed in the upper part of the drain reservoir is installed, and a condensate inflow passage with a check valve is installed. An outflow passage connected to the upper part of the drain reservoir and having an electrically operated shut-off valve interposed therebetween is connected to the lower part of the drain reservoir, and the shut-off valve is closed when the water supply pump is operated;
A drain recovery device that is equipped with a means to operate an on-off valve so that it opens when the valve is stopped.