JPH0424247Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a blowing device suitable for steam boilers used in food processing, cleaning industries, etc., particularly for relatively small-capacity once-through steam boilers.

[Conventional technology]

Conventional relatively small-capacity boilers hold a small amount of water relative to the amount of evaporation, so even if a can water softener is used, can water condenses quickly and is prone to water problems such as scaling and carryover.

Furthermore, since the heat capacity of the boiler body is small, the boiler cools down quickly after the operation is stopped, resulting in negative pressure inside the boiler, which causes corrosion of the boiler body as air is sucked in from the outside.

On the other hand, even if chemicals are added to the boiler to adjust the pH of the canned water, the pH of the drain that adheres to the walls of the steam chamber is low, and if oxygen in the air dissolves in this, the can body will corrode immediately. . Most of the corrosion in small capacity boilers is said to be caused by this.

As mentioned above, small-capacity steam boilers have the drawback of being susceptible to corrosion due to scaling and carryover even if a suitable softener is installed or chemical injection is performed.

For this reason, operators of small-capacity boilers have traditionally been required to blow the boilers manually at the beginning of operation. However, since almost no countermeasures were taken to prevent corrosion after shutdown, the boiler had the drawback of having a very short lifespan.

[Problem that the invention attempts to solve]

This invention was developed in view of the above-mentioned drawbacks of conventional steam boilers.
To provide an inexpensive blowing device that automatically performs all blowing to prevent scaling and carryover of a steam boiler, eliminates handling errors, and further prevents corrosion.

[Means for solving problems]

The present invention is applicable to a steam boiler, particularly a small-capacity once-through steam boiler, which is equipped with an automatic valve connected to the lower part of the can body or the lower header, and an orifice or control valve for controlling the flow, and the automatic valve is electrically linked with an operation stop signal. This steam boiler blowing device is equipped with an electric circuit that operates an automatic valve after a certain time delay from the operation stop signal.

〔Example〕

FIG. 1 shows an embodiment of the present invention in which an automatic valve is connected to a lower header, and FIG. 2 shows an embodiment of an electric circuit for operating the automatic valve.

The automatic valve 1 is connected to the lower header 2 of the steam boiler, and during operation, the power switch Sw shown in Figure 2 is turned on.
is turned on.

At the end of operation, when the stop button PB ₂ is pressed, the burner stops, and when the power switch Sw is turned off, the boiler operation is completely stopped.

Then, the automatic valve is opened, the can water is completely blown away, and the interior of the can is further dried by residual heat inside the can.

The electric circuit for operating the automatic valve 1 may be any type as long as it operates the automatic valve in response to a stop signal, and is not limited to the electric circuit shown in FIG. 2. Furthermore, although the automatic valve opens at the same time as the stop signal in Figures 1 and 2, a timer may be installed to slightly delay the opening time of the automatic valve in relation to residual heat of the boiler body after the operation is stopped. . By doing this, the pressure of the boiler becomes low and there is less residual heat, so there is no need for a drainage cooling device, and it is also possible to prevent damage to the valve seat due to wear, thereby extending the life of the valve seat. is possible.

PB ₁ is the burner operation button, SW power switch,
R ₁ indicates the burner operation signal.

Furthermore, an orifice or a control valve may be provided to control the discharge flow path of boiler canned water to control its discharge.

In Fig. 1, 3 is a water pipe and 4 is an upper header.

[Effect of idea]

When this invention is installed in a steam boiler, especially a small-capacity steam boiler, the concentrated canned water is automatically blown out at the end of the boiler operation. The work that used to require a little preheating, increasing the pressure, blowing it all out, filling it with water again, and starting up is no longer necessary with this invention.

Furthermore, even if the automatic valve operates after a certain time delay at the end of the operation, of course there is residual heat, so the moisture attached to the wall after blowing will evaporate and be completely removed from the wall.
This has the advantage that corrosion of the can body is prevented because the wall surface is dry.

Since the automatic valve operates after a certain period of time after the operation is stopped, there is an advantage that no drainage cooling device is required.

Thus, the present invention eliminates scaling, carryover, and corrosion in the boiler, makes it easy to obtain high-quality steam, is low in cost, causes less damage to valve seats, etc., and extends the life of the boiler. play.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of one embodiment of the invention, and FIG. 2 shows an electrical circuit for operating the invention. 1... Automatic valve, 2... Lower header, 3... Water pipe, 4... Upper header, PB ₁ ... Burner operation button, PB ₂ ... Burner stop button.

Claims (1)

[Scope of utility model registration request] A steam boiler is equipped with an automatic valve connected to the lower part of the can body or the lower header, and an orifice or control valve that controls the flow rate, and the automatic valve is electrically linked with an operation stop signal and is delayed by a certain period of time from the operation stop signal. A steam boiler blowing device characterized by being equipped with an electric circuit that operates an automatic valve.