JPS5912925B2 - Boiler drain recovery device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drain recovery device for a steam boiler.

The water that is condensed when the steam sent from the boiler is dissipated in the heat exchanger, that is, the condensed water, still has a considerable amount of heat, and devices that recover this water and return it to the boiler have become particularly important in recent years from the perspective of energy conservation. has been done.

However, conventional devices of this type have a complicated structure, require other power sources to operate the device, and conventional devices that operate using their own steam energy have the problem of low efficiency. there were.

As a result of various research and experiments, the present inventor found that in a drain recovery device that sends condensate to a boiler using a piston that moves up and down inside the pump, the condensate is used as energy when flowing condensate into the drain chamber of the pump. It is very efficient and energy efficient to use the own pressure and reduce the pressure in the drain chamber to at least the pressure of the drain pipe leading the drain to the drain chamber before allowing the drain to flow into the drain chamber. They discovered that the loss was extremely small and completed the present invention.

That is, an object of the present invention is to provide a drain recovery device that is highly efficient and has extremely low energy loss.

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a system diagram of a drain recovery device according to the present invention,
In the figure, 1 is a boiler, and a steam discharge pipe 2 of the boiler 1 is connected to a hender 3, and the steam distributed by the hender 3 is transferred to heat as a load placed at various locations through conduits 4. It is added to exchangers 5, 5...

The drain condensed in the heat exchanger 5 is connected to the drain hole 10 of the pump 9 via the drain pipe 6 and the check valve 8, and is connected to the drain outlet 10 of the pump 9. The hole 11 has a drain discharge pipe 1 communicating with the boiler 1.
2 are connected via a check valve 13.

Furthermore, in the drain pipe 6, a bypass pipe 7 having a bypass operation valve Sv3 in the middle is connected between the Trumpet 6a and the check valve 8 and between the check valve 13 and the drain discharge hole 11. ing.

The pump 9 has a large diameter cylinder 15 as shown in FIG.
and a small diameter cylinder 16 are superimposed and communicated with each other internally, and this large diameter cylinder 15 has a steam side pressure receiving plate 1.
A drain side pressure receiving plate 18 is inserted into the small diameter cylinder 16, and the steam side pressure receiving plate 17 and the drain side pressure receiving plate 18 are connected by a connecting iron 19.

The piston 14 is formed by the drain side pressure receiving plate 18, the steam side pressure receiving plate 17, and the connecting iron 19, and the piston 14 is formed by the drain side pressure receiving plate 18, the steam side pressure receiving plate 17, and the connecting rod 19.
A space created by the upper surface is defined as a drain chamber 20, and a space created by the inside of the large diameter cylinder 15 and the lower surface of the steam side pressure receiving plate 17 is defined as a steam chamber 21.

A small tank 26 is provided in the drain pipe 6 between the check valve 8 of the drain inflow hole 10 and the bypass pipe 7,
A drain sensor S is attached to the small tank 26, and a pressure gauge PG is attached between the check valve 8 and the drain hole 10.

Further, an upper limit sensor LU and a lower limit sensor LD for detecting the upper and lower limit positions of the piston 14 are attached to the upper position of the large diameter cylinder 15, and an air hole 23 is formed. .

On the other hand, the conduit 4 that leads the steam to the heat exchanger 5 is branched into a steam pipe 22, and the steam pipe 22 is connected to a steam inflow hole 24 communicating with the steam chamber 21 via a steam inflow operation valve Sv0. ing.

Also, a steam discharge hole 25 communicating with the steam chamber 21
An orifice 25a is formed in a part of the steam discharge hole 25, and the steam discharge hole 25 is connected to a discharge pipe 27 via a steam discharge operation valve Sv2.

In addition, 28 in the figure is a water softener that softens make-up water for the boiler 1, and the water softener 28 is connected to the boiler 1 via a water softening tank 29 and a pump 30, and is present at various locations in the figure. V is manual pulp.

To explain the operation of the device with the above configuration, first, steam generated from the boiler 1 passes through the steam discharge pipe 2 to the hender 3.
There, the vapor pressure is adjusted to a predetermined value, and the vapor is supplied via conduits 4 to heat exchangers 5 installed at various locations.

The steam-mixed drain condensed in the heat exchanger 5 flows through the check valve 8 from the drain hole 10 into the drain chamber 20 of the pump 9 under its own pressure. Each of the operation valves Sv1, Sv2, and Sv3 is subjected to the sequence control shown in FIG. 4.

That is, the steam inflow operation valve Sv1 is opened only in the range of ■, the steam discharge operation valve Sv2 is opened only in the range of O, and the bypass operation valve Sv3 is opened in the range of ■ and 00.

However, in the order of ■, ■, 0, 0, each of the operation valves S
v1, Sv2, and Sv3 are operated to open and close,
The transition from the [Yes] range to the ■ range is performed by the upper limit limit sensor LD detecting the upper limit position of the piston 14, and the transition from the ■ range to the 00 range is performed by detecting the upper limit position of the piston 14.
This is performed by the pressure gauge PG detecting a predetermined pressure within 0, and the transition from the 0 range to the 00 range is performed by the lower limit sensor LD detecting the lower limit position of the piston 14. , 0 to the range (3) is performed after the expected time period required for steam in the drain chamber 20 to escape to the heat exchanger 5 side through the bypass pipe 7 and for drain to flow in instead.

By controlling the opening/closing operation of each of the valves SV1, Sv2, and Sv3 described above, the piston 14 and the drain operate as shown in FIG. 3.

That is, FIG. 3a corresponds to the range of O mentioned above, and when the steam in the steam chamber 21 is gradually discharged through the orifice 25a, the condensate gradually flows into the drain chamber 20 due to the pressure of the condensate itself. There will be an influx.

At this time, if the presence of drain is not detected by the drain sensor S, the discharge operation valve Sv2 is closed and the piston 1
4 is stopped and held until drain is detected.

In this way, due to the slow descent of the piston 14 by the orifice 25a and the drain sensor S, almost no steam enters the drain chamber 20, and the drain chamber 20 is almost completely filled with drain.

Here, the above-mentioned 0 range is reached, the bypass operation valve Sv3 is opened, and the steam that has entered the drain chamber 20 is transferred to the bypass pipe 7.
The drain is returned to the heat exchanger 5 through the drain, and the drain chamber 20 is filled with the drain by further flowing in instead.

When the drain chamber 20 is filled with condensate in this way, it moves to the range (2) above, and when steam flows into the steam chamber 21, the pressure receiving area of the steam side pressure receiving plate 17 is compared to the pressure receiving area of the drain side pressure receiving plate 18. Therefore, the piston 14 will rise and the drain will be sent to the boiler 1 as shown in Figure 3.

When the piston 14 rises to the upper limit, the upper limit limit inte LU detects this and shifts to the range (2).

When the bypass operation valve Sv3 is opened in this way, the drain chamber 20, which had been at a higher pressure than the boiler 1, is transferred to the heat exchanger 5.
The pressure can be lowered to approximately the same pressure as that of

Therefore, when moving to the next 00 range, the pressure in the drain chamber 20 will be maintained at a slightly lower state than the pressure on the heat exchanger 5 side as the piston 14 descends, and the pressure in the drain chamber 20
Drainage inward is carried out well.

The changes in the pressure PS in the steam chamber 21 and the pressure PD in the drain chamber 20 due to the above-mentioned operation are as shown in the pressure curve shown in FIG. The pressure in the drain chamber 20 that rises decreases in the range (3), and is considered to be a low pressure before the range (C) into which drain flows.

In this way, the steam energy used to recover the drain, that is, the steam energy flowing into the steam chamber 21, can be used very efficiently.

In the above-mentioned device, by appropriately setting the lengths of the piston 140 and the iron 19, the amount of drain fed can be changed without changing the size of the pump 9.

Therefore, simply by manufacturing a large number of pumps 9 of the same size and preparing irons 19 of different lengths, it is possible to easily provide a large number of pumps with different feed rates.

As explained above, according to the present invention, the drain side pressure receiving plate 1
8 to lead drain from the downstream side of the heat exchanger 5 into the drain chamber 20, the operating valve Sv of the bypass pipe 7
3 is opened, and the pressure in the drain chamber 20 receiving the force in the negative pressure direction is instantly made to be about the same as the pressure on the downstream side of the heat exchanger 5. Therefore, the high temperature drain flows into the drain chamber 20 (・
There is an advantage that the drain can be effectively recovered without being vaporized, and the recovered drain can be transferred to the boiler 1 using the steam pressure downstream of the heat exchanger 5.

Further, in the present invention, if the connecting rod of the piston is made detachable, the effect that the drain feed amount can be easily changed by simply replacing the connecting rod with a rod of a different length is produced.

[Brief explanation of the drawing]

The figures show one embodiment of the device according to the present invention, in which Fig. 1 is a system diagram, Fig. 2 is a main part configuration diagram, Fig. 3 is an explanatory diagram of operation, and Fig. 4 is a time diagram of the operating valve. It is a graph diagram showing a chart and pressure changes in a drain chamber and a steam chamber corresponding to the time chart. 1...Boiler, 5...Heat exchanger, 6.
...Drain pipe, 7...Bypass pipe, 8,
13...Check valve, 9...Pump, 12
...Drain discharge pipe, 14...Piston, 15...Large diameter cylinder, 1d...Small diameter cylinder, 17...Steam side pressure receiving Board, 18
...Drain side pressure receiving plate, 19...Connection rond, 20...Drain chamber, 21...Steam chamber, 22...Steam pipe , Sv3...
...Bypass operation valve.

Claims (1)

[Claims] 1. A drain recovery device that sends drain discharged from a heat exchanger to a boiler by a piston that moves up and down in a pump, and the pump has a large diameter cylinder and a small diameter cylinder on the same axis. A steam side pressure receiving plate, which constitutes a part of the piston, is inserted into the large diameter cylinder, and the steam chamber created by the steam side pressure receiving plate inside the large diameter cylinder is connected to the steam chamber from the upstream side of the heat exchanger. A steam pipe that guides steam to the steam chamber is connected, and a drain side pressure receiving plate is inserted into the small diameter cylinder, which is connected to the steam side pressure receiving plate via a connecting iron. The drain chamber made of a plate is connected to a drain pipe that leads drain from the downstream side of the heat exchanger and a drain discharge pipe that leads drain from the drain chamber to the boiler. In the drain recovery device, a bypass pipe in which a bypass operation valve is interposed in an intermediate portion is connected between the drain discharge pipe and the drain pipe, and a connection part of the drain discharge pipe with the bypass pipe is connected to the boiler. A check valve that allows flow toward the boiler is interposed between the drain pipe and the drain chamber, and a check valve that allows flow toward the drain chamber is provided between the drain pipe and the bypass pipe and the drain chamber. A drain recovery device characterized in that a check valve is provided, and the bypass operation valve is opened when the drain side pressure receiving plate located at the top dead center of the drain chamber moves toward the bottom dead center. Device. 2. A drain recovery device for a boiler according to claim 1, wherein the connecting rod connecting the steam side pressure receiving plate and the drain side pressure receiving plate is detachable from each pressure receiving plate.