JPH0547927Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field] This invention relates to a blowing device for concentrated can water in a multi-tubular once-through boiler.

[Prior art]

Normally, in once-through boilers, the can water is highly concentrated, and dryness decreases due to scale adhesion to the can body and carry over, so blowing operations must be performed frequently. At that time, it is preferable to perform all the blowing and release all the canned water at once, but in reality, all the blowing is required because the heat loss is large and the boiler must be stopped during the blowing. What is done every time is not done. Therefore, in general, continuous blowing is performed, concentrated can water is discharged from the upper part of the can body, and steam dryness is maintained at a high level, thereby reducing the total number of blows.

This kind of continuous blowing includes blowing hot water separated by a steam-water separator while adjusting the discharge amount with a control valve, and blowing when the hardness reaches a certain level using a hardness tester, etc. What you do is known.

However, in the former case, the valve opening degree must be constantly checked in order to obtain an appropriate blow amount, and automatic control is costly. Furthermore, even in the latter case, the device itself is complicated and expensive, and is not suitable for small boilers that require a small amount of steam to be supplied.

[Summary of the idea]

This invention aims to solve the above-mentioned problems by providing a blowing device that is inexpensive and can maintain dryness for a relatively long time.

That is, this invention includes a piston member that operates to close and open a blow discharge hole, and a spring that biases the piston member in a direction to close the discharge hole, and the piston moves against the biasing force of the spring. In order to operate the member in the opposite direction, a back pressure chamber is provided, this back pressure chamber is communicated with the water supply pipe, and a blow passage connected to the discharge hole is connected to the blow pipe attached to the boiler body. It is characterized by being connected.

〔Example〕

Hereinafter, embodiments of this invention will be described with reference to the drawings. In Fig. 1, 23 is the boiler main body that implements this invention, and the steam supply pipe 1 is attached to the upper part.
4 and a separator 15 connected to this supply pipe
is provided. A downcomer pipe 16 extending from the lower part of the separator branches into a blow pipe 17 on the way, and a portion returns to the lower part of the can body. Water is supplied to the boiler body by a water supply pump 21, and during the
Water is supplied to the lower part of the can through a water supply pipe 20 via a check valve 22.

Reference numeral 1 denotes a blowing device main body, and in this embodiment, the interior is divided into two by a partition wall 5 between a back pressure chamber 4 and a flow path 7, and a discharge hole 8 is provided at the upper end side.
A blow pressure adjustment screw 12 is screwed on the lower end side. Between the back pressure chamber 4 and the flow path 7, a piston member 6 that can freely slide is installed in a watertight manner through the partition wall 5, and its tip 6a acts as a valve member to close and open the discharge hole 8. It is set up so that Reference numeral 11 denotes a spring that biases the piston member in a direction in which the discharge hole 8 is closed. The elastic force of this spring can be adjusted by moving the blow pressure adjustment screw 12 forward.
13a and 13b indicate O-rings. or,
A water volume adjustment screw 10 with a needle-shaped tip is installed between the discharge hole 8 and the blow outlet 9, and by adjusting the entrance and exit of the screw, and changing the cross-sectional area of the flow path, the blow volume can be adjusted to the optimum amount. It can be adjusted to

Water supply pipe 2 that communicates the check valve 22 and the pump 21
0 and the back pressure inlet 3 are communicated by a back pressure pipe 19, so that the discharge pressure of the pump is directly transmitted to the back pressure chamber. Of these, blow tube 1
7 is connected to the blow inlet 2, and the blow outlet 9 communicates with the discharge pipe 18. [] In the above configuration, the steam generated from the boiler main body 23 is taken out of the can body through the steam supply pipe 14, separated from carried-over condensate by the separator 15, and becomes high-quality steam. Supplied outside the system. Further, one part of the separated drain is returned to the lower part of the can through the downcomer pipe 16, and the other part is led to the blowing device main body 1 through the blowing pipe 17.

On the other hand, water is supplied to the boiler by driving the water supply pump 21, and normally the discharge pressure of the water supply pump is set sufficiently higher than the internal pressure of the can, and water is supplied into the boiler against the internal pressure of the can. The water supply pump is linked to the water level inside the can, and is controlled on and off so that the water level inside the can is always at a constant position.

Under such usage conditions, in the case of the control operation described above, if the resistance of the spring 11 built into the blow device main body 1 is set to be greater than the internal pressure of the can and smaller than the water supply pump discharge pressure, the water supply will stop. When the pump is turned on, the discharge pressure of the water supply pump transmitted to the back pressure chamber through the back pressure pipe 19 causes the cylinder 6 to move in the direction of opening the discharge hole 8 against the force of the spring 11. Therefore, the discharge hole 8 is opened, and the drain led from the blow pipe 17 to the flow path 7 is discharged from the blow outlet through the discharge pipe 18.

On the other hand, when the water supply pump is turned off, the discharge pressure of the water supply pump is no longer applied to the back pressure chamber, so the cylinder closes the discharge hole 8 by the force of the spring. As a result, the drain flow stops,
The blow will stop.

[Effect of idea]

Since this invention has the above-mentioned configuration, it can bring about the following practical effects.

(1) Blow is not performed all the time, but only when the water supply pump is turned on, so there is no need to worry about the water level in the can dropping too much, and the water level can be easily controlled.

(2) Although it has a simple structure that does not require complicated equipment such as hardness sensors, it can reliably blow out concentrated canned water and keep the amount of carry over low for a long time, resulting in high dryness. steam can be supplied for a longer period of time than conventional boilers without blowing equipment.

(3) Since blowing is performed only when water is supplied, the efficiency of heat exchange between blow water and supply water can be increased.

[Brief explanation of drawings]

FIG. 1 is a flow sheet showing an example of this invention. FIG. 2 is a sectional view of a main part showing an embodiment of this invention. 1...Blow device main body, 2...Blow inlet, 3
... Back pressure inlet, 4 ... Back pressure chamber, 6 ... Piston member, 9 ... Blow outlet, 23 ... Boiler main body.

Claims (1)

[Scope of utility model registration request] It includes a piston member 6 that operates to close and open the blow discharge hole 8, and a spring 11 that biases the piston member in a direction to close the discharge hole, and the piston member operates against the biasing force of the spring. In order to operate in the opposite direction, a back pressure chamber 4 is provided, and this back pressure chamber is communicated with the water supply pipe 20, and a blow passage 7 connected to the discharge hole is connected to a blower attached to the boiler body 13. A blow device linked to a water supply pump, characterized in that it communicates with a pipe 17.