JPS6298101A - Superheating preventive device for boiler body using two-throw water level - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] This invention relates to a boiler can body overheat prevention device using a so-called dual water level system, which is provided with a water level detection rod during start-up separately from a water level detection rod during steady state. It is.

Overheating of the boiler can is noticeable during cold startup.

In order to prevent this, as shown in Figs. 1 and 2, the water level detection rod C during normal operation and the water level detection rod C during startup are separately installed via the contacts of relay x 1, and the At startup when the pressure is lower than the set pressure of the pressure switch PS, the contact of relay x 1 is switched to the water level detection rod at startup to raise the water level and prevent overheating of the boiler can. If the pressure exceeds the set pressure of the steam pressure switch PS, the blow solenoid valve B
W is operated for the time set by timer T to return the water level to a steady water level to prevent a decrease in steam dryness and to prevent wet steam from coming out when steam is supplied.

Since this device operates only at low pressure during start-up, heat loss due to blowing can also be minimized.

? ! ! If the source terminals R and S are connected to the boiler main power supply, it will operate only once when the boiler main power supply is turned on.

Also, if it is connected to the boiler operation switch line, it will only operate once when the operation switch is turned on.

In this case, since the boiler is operated only once in the morning, when the boiler is restarted after the full blow, the water level remains one arm above the starting water level, thereby preventing the boiler body from overheating.

Furthermore, if the electric currents R and S are connected to the combustion line of the boiler, the combustion cycle will be repeated until the pressure becomes low, thereby preventing the boiler body from overheating during the repetition.

In the figure, F is the start signal on the boiler side (magnet I of the blower, etc.), X2 is the relay, A is the water level detection rod for stopping the burner, B is the water level detection rod for operating the water pump, and C is the water level detection rod for stopping the water pump. (at steady state), D is a water level detection rod for stopping the water supply pump (at startup).

A thermostat (not shown) may be used instead of the steam pressure switch PS. That is, at startup when the temperature is below the set temperature of the thermostat, the relay contact is switched to the water level detection rod at startup to raise the water level and prevent overheating of the boiler can. Thereafter, when the temperature exceeds the set temperature of the thermostat, the blow solenoid valve is operated for the time set on the timer to return the water level to the steady water level and prevent a drop in air dryness.

In the case of the above-mentioned device, blowing is performed on a timer, so even if the boiler water level falls below the normal water level in a steady state, blowing may be performed at the same time as the water pump is activated.

Therefore, the problem can be solved by using a device as shown in FIG. In other words, when the pressure exceeds the set pressure of the steam pressure switch PS, the blow solenoid valve BW is activated and the water supply pump is activated.
After 1J, the blow solenoid valve BW is stopped and covered to prevent the blow and water supply from overlapping. Such a device results in water savings and power savings.

□ In the figure, ×3 is a relay, and P is a magnet for the boiler water pump.

To explain the operation, when starting at low pressure, the boiler side signal F is 011, and the steam pressure switch
) The b contact side of S is on. Therefore, relay x1 becomes 011, and the water level detection rod is switched to the one for starting (D in Fig. 2). The water level is 3il″cJ to the water level at startup.
If so, the water pump becomes oH. When the steam pressure exceeds the set pressure, the steam pressure switch PS is switched and the relay x2 becomes Oll and is self-maintained.

Relay x1 contains the b contact of relay x2, so if the steam rises, the water level will be detected by the detection rod (C in Figure 2) below the steady water level. The blow solenoid valve BW operates and starts blowing. When the water level drops due to the blow and becomes below the steady water level (B in Figure 2), the water supply pump is activated. This is detected from the contact point of the water pump magnet P, and relay x3 becomes 011 and is self-held. Then, set the blow solenoid valve BW to 0 and stop the blow.This circuit is Rl
It is held until S is powered off.

Of course, a thermostat (not shown) may be used instead of the steam pressure switch PS.

By the way, the degree of overheating of the can during the re-ignition operation at low pressure and at high pressure is greater when starting at low pressure.

For this reason, the timing to activate the double water level is determined by the steam pressure of the boiler, and when the pressure is low, it is activated during pre-purge, and when the pressure is high, it is activated after combustion begins. In other words, it prevents water from entering under high pressure and maintains the dryness of steam (see Figure 4).

[Brief explanation of drawings]

1 and 2 are circuit diagrams showing an embodiment of the present invention. FIG. 3 is a circuit diagram showing another embodiment of the invention. FIG. 4 is a circuit diagram showing a further embodiment of the present invention. Patent applicant Miura Kogyo Co., Ltd. Figure 1
Figure 2 Figure 3 Figure 4 Double water level power supply

Claims (3)

[Claims] (1) The water level detection rod during steady state and the water level detection rod during startup are installed separately via relay contacts, and when the pressure is lower than the set pressure of the steam pressure switch, the relay contacts are set at startup. Switch to the water level detection rod to raise the water level and prevent the boiler body from overheating.When the pressure exceeds the set pressure of the steam pressure switch, the blow solenoid valve is activated, and when the water supply pump is activated, the blow solenoid valve is activated. A boiler can body overheat prevention device using dual water levels, characterized in that a valve is stopped and the water level is returned to a steady water level to prevent a decrease in steam dryness. (2) A water level detection rod during steady state and a water level detection rod during startup are installed separately via relay contacts, and when the temperature is lower than the thermostat set temperature, the relay contact detects the water level at startup. Switch to the rod and raise the water level to prevent the boiler body from overheating.When the temperature exceeds the thermostat set temperature, the blow solenoid valve is activated, and when the water pump is activated, the blow solenoid valve is stopped. A boiler body overheat prevention device using double water levels, characterized in that the water level is returned to a steady water level to prevent a decrease in steam dryness. (3) A patent claim characterized in that the timing at which the double water level is activated is determined by the steam pressure of the boiler, and when the pressure is low, it is activated during pre-purge, and when the pressure is high, it is activated after combustion begins. A boiler body overheat prevention device using the double water level according to the range 1 or 2.