JP2709437B2 - Automatic full blow device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for automatically performing a full blow of a boiler.

[0002]

2. Description of the Related Art As boiler water evaporates, the concentration of suspended solids and dissolved salts gradually increases, causing carryover,
Generate scales and kamado. To prevent this, it is necessary to drain the boiler water and replace it with fresh water.

[0003] The operation of all blows for replacing all of the canned water is performed manually. In the full blow method, first, combustion of the boiler is started, and the operation is stopped when the steam pressure reaches a gauge pressure of 1-2 kg / cm2. Thereafter, all the blow valves at the bottom of the can are opened, the can water is blown using the pressure difference, and when the steam pressure becomes 0 kg / cm2, the air intake valve at the top of the can is opened to further promote the blow. After confirming that the blow has been completed, all the blow valves and the air intake valve are closed, and the entire blow operation is completed. Opening the valve when the pressure in the can is high is dangerous, and opening the valve at low pressure results in insufficient blowing. The blower blows on the basis of steam pressure and intuition, and the blow state varies.

[0004]

By automating all blow operations relying on intuition, optimal blow control can always be performed, thereby shortening the blow time and saving labor.

[0006]

Means for Solving the Problems A steam temperature measuring device for measuring a steam temperature, a blow control device for performing a blow control based on the steam temperature during a full blow operation, and a full blow valve for automatically opening and closing by a signal from the blow control device And an air intake valve and a water detection device for detecting the presence or absence of water at the bottom of the can. In the blow control device, a full blow valve opening control temperature, a full blow valve / air intake valve closing control temperature, and an air intake valve opening control temperature when the full blow valve is open are set. When the full blow operation is started, the blow control device starts detecting the steam temperature. If the steam temperature is lower than the temperature for controlling the opening of all the blow valves, combustion is performed. When the steam temperature reaches the set temperature, all the blow valves are opened, and blowing is started. afterwards,
When the steam temperature decreases and reaches the set temperature, the air intake valve also opens to promote blowing. If the water detector at the bottom of the can starts detecting the absence of water, it is considered that all the blows have been completed, all the blow valves and the air intake valve are closed, and preparation for the combustion operation is started. If the steam temperature rises during the entire blow and reaches the set temperature, all the blow valves and air intake valves are closed to prevent steam backflow. After that, all the blows are restarted after the steam temperature decreases.

[0007]

Since the blow control is performed based on the steam temperature, fine control can be performed. The abnormal overheating of the water pipe, which cannot be determined by the pressure, is predicted, and the backflow of the steam can be prevented by interrupting the blow.

[0008]

An embodiment of the present invention will be described. Boiler (1)
Temperature sensor that measures the steam temperature in the steam section of the car (2)
, An air intake electromagnetic valve (6) is provided, and an all blow electric valve (4) and an all blow electrode rod (5) for detecting the presence or absence of water are provided in an all blow water distribution pipe (3) below the boiler. Each detector and valve is connected to a full blow control (7), which is also connected to a combustion control (8).

In this case, the steam temperature is from 111 ° C. to 115 ° C.
Open control of all blow motor valves at 117 ° C, closed control of all blow motor valves and air intake solenoid valve at 117 ° C, open air intake solenoid valve when all blow motor valves are open and steam temperature is 105 ° C Set it to be controlled. When the blow operation is started, the blow control device reads the temperature output from the temperature sensor. First, the steam temperature is changed from 111 ° C to 11
Control is performed so that the set temperature of the full blow motor-operated valve opening is 5 ° C. If the steam temperature is low, a start of combustion is output to the combustion control device. If the steam temperature is high, the full blow standby state is set, and the temperature decreases. Wait for. When the steam temperature reaches the set temperature for controlling the opening of all the blow electric valves, if the combustion is performed, the operation is stopped, the all blow electric valves are opened, and the blow is started. Usually, the subsequent steam temperature decreases due to the release of heat by blowing, and the pressure in the can also decreases. When the temperature sensor informs the blow control device that the steam temperature has dropped to 105 ° C, the blow control device opens the air intake solenoid valve,
Encourage blow. When all the blow electrode rods detect the absence of water, the blow is terminated and the all-blow electric valve and the air intake solenoid valve are closed. When the end of all blows is output, the water supply control device starts water supply and starts normal control.

[0010] During the blow operation, when a backflow of steam occurs, the steam temperature rises. When the steam temperature reaches 117 ° C., the blow control device closes all the blow motor valves and the air intake solenoid valve to prevent fluctuations in the pressure inside the can and to prevent backflow of steam. Thereafter, when the steam temperature drops to 115 ° C., all the blow electric valves are opened to restart all the blows.

[0011]

According to the present invention, all the blow operations, which vary due to manual operation, can be automatically operated depending on intuition, and optimal and stable control can always be performed. In addition, when the backflow of steam occurs, it can be detected immediately, and the blow is stopped to prevent the backflow, so that abnormal overheating of the water pipe can be prevented.

[0012]

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boiler 2 Temperature sensor 3 Drain pipe for all blows 4 All blow electric valve 5 All blow electrode rod 6 Air intake solenoid valve 7 All blow control device 8 Combustion control device

Claims (1)

(57) [Claims] A steam temperature measuring device for measuring a steam temperature of a boiler; an air intake valve for taking air into a water pipe;
It has a full blow valve for discharging can water from the lower header and a water detection device that detects the presence of water at the bottom of the lower part of the water pipe.The air intake valve and all blow valves can be electrically opened and closed, and the steam temperature A multi-pipe once-through boiler that is connected to a measuring device, an air intake valve, and all blow valves, and is provided with a full blow control device that controls the opening and closing of the air intake valve and all blow valves. In addition, the steam temperature for opening and closing the air intake valve is set in the all-blow control device, and during the full-blow operation, first, the combustion operation is performed until the steam temperature reaches the temperature at which all the blow valves are opened. An automatic full blow apparatus characterized in that the opening and closing of all blow valves and air intake valves are controlled by the steam temperature measured in (1).