JPH03211386A - Burner ignition judgement device in grain dryer - Google Patents

Abstract

PURPOSE:To eliminate ignition failure by a method wherein when it is judged based on a signal of a flame sensor that a burner is not ignited, changes in the rising temperature detected by a hot-air temperature sensor are compared and when the change in the rising temperature exceeds the specified value, the presence or absence of flame of the burner is judged again based on the signal of the flame sensor. CONSTITUTION:When a first time period has elapsed after a burner 10 is ignited, an ignition judgment device judges based on the signal of a flame sensor whether or not the burner is ignited. When it is judged that the burner is not ignited, a re-judgment instruction device compares the rising change in detected temperature of a hot-air temperature sensor 22 with the specified value, and outputs a re-judgment signal when the rising change exceeds the specified value. When the re-judgment signal is outputs and a second time period has elapsed, the ignition re-judgment device judges again based on the detected signal of the flame sensor 42 whether or not the burner is ignited. Thereby, miss ignition can be diminished.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a grain dryer that dries grain with hot air from a burner.

(Prior Art) Conventionally, this type of grain dryer has been equipped with a hot air temperature sensor that detects the hot air temperature of the burner and a flame sensor that detects the presence or absence of the burner flame. After a predetermined period of time (seconds, etc.) has elapsed, it is determined whether or not the burner has ignited based on the detection signal of the flame sensor, and only when it has ignited, the process moves to the normal combustion process, and if it has not ignited, it is considered an ignition error and is abnormal. What it processes is known.

(Issue to be solved by the invention) However, the burner has the property of being a red flame immediately after being ignited, and gradually changing to a blue flame.

On the other hand, flame sensors have the property that they cannot detect red flames due to their configuration.

Therefore, if the red flame continues even though the burner is in the ignition state, the flame sensor cannot detect the red flame, so there is a drawback that it is treated as an abnormality as an ignition error.

The present invention aims to eliminate this drawback.

(Means for Solving the Problems) In order to achieve the above object, the present invention was configured as follows.

That is, the present invention provides a grain dryer that dries grain with hot air from a burner and includes a hot air temperature sensor that detects the temperature of the hot air from the burner, and a flame sensor that detects the flame of the burner. ignition determination means for determining whether or not the burner is ignited based on the detection signal from the flame sensor after a first period of time has elapsed; re-judgment instructing means for comparing the increase change with a predetermined value and outputting a re-judgment signal when the increase exceeds the predetermined value; The ignition re-determination means re-determines whether or not the burner is ignited based on the detection signal.

(Function) In the present invention configured as described above, when the burner is ignited, the ignition determination means determines that, after the first time has elapsed since the ignition,
It is determined whether the burner is ignited or not based on the detection signal of the flame sensor.

When it is determined that there is no ignition, the re-judgment instructing means compares the increase in the temperature detected by the hot air temperature sensor with a predetermined value, and outputs a re-judgment signal when the temperature exceeds the predetermined value.

When the re-determination signal is output, the ignition re-determination means re-determines whether or not the burner is ignited based on the detection signal from the flame sensor after a second period of time has elapsed.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of a grain dryer embodying the present invention. In FIG. Install it at an angle so that the grain chamber 3 is installed by each grain board 2.
form.

Two mesh plates 4 are connected in parallel to each lower side of the floating grain plate 2,
A drying chamber 5 is formed between them. Then, a hot air chamber 6 in which a centrifugal spray type (rotary type) burner 10 as a drying heat source is installed is formed between the two inner mesh plates 4 provided near the center of the storage chamber l, and the outer two mesh plates An exhaust chamber 8 is formed between the mesh plate 4.4 and the left and right machine walls 7, and is connected to an exhaust fan 9 of the exhaust chamber 8.

Reference numeral 11 denotes a grain collection room formed in the shape of a gutter, and a lower helix 12 is installed at the bottom of the grain collection room, and its terminal end is connected to the lower entrance of the elevator 13. Reference numeral 14 denotes a rotary valve pivotally supported at the lower end outlet of the drying chamber 5, and its rotation causes the grains in the storage chamber 1 to flow out through the drying chamber 5 into the grain collection chamber 11.

The upper outlet of the elevator 13 is connected to an upper helix 15 installed on the ceiling of the storage chamber l, and the outlet of this upper helix 15 looks into the storage chamber l.

20 is a moisture meter that measures the moisture value of the grain during drying, and 22 is a hot air temperature sensor installed in the hot air chamber 6 to measure the hot air temperature of the burner IO.

23 is a fuel pump that supplies fuel to the burner 10;
24 is a fuel valve that adjusts the fuel supplied to the burner 10.

FIG. 2 is a block diagram showing an example of a control system according to an embodiment of the present invention.

In the figure, 25 is a CPU in the form of a macroprocessor.
(central processing unit), which controls each component according to a predetermined procedure as described below.

Reference numeral 26 denotes an operation switch section in which a drying switch, a tensioning switch, a discharge switch, a stop switch, etc. are arranged, and is connected to an input circuit 27.

The input circuit 27 includes a paddy flow sensor 28 that detects the presence or absence of paddy flow in the dryer, a fullness sensor 29 that detects whether or not the storage chamber l is full of paddy, and sets the amount of grain to be loaded. A rotary switch 30, a rotary switch 31 for setting a target moisture value when stopping drying, a rotary switch 32 for selecting grain to be dried, etc. are connected.

Further, the input circuit 27 is connected to a moisture meter 20 that measures grain moisture through an A/D conversion circuit 33 and a hot air temperature sensor 22 that detects the hot air temperature of the burner 10.

34 is an output circuit connected to the CPU 25, and this output circuit 34 includes the fuel pump 23, the fuel valve 24, an ignition heater 34 that ignites the burner 10, an exhaust fan motor 35 that drives the exhaust fan 9, and an exhaust fan motor 35 that drives the elevator 13. An elevator motor 36 that drives the rotary valve 14 and a valve motor 37 that drives the rotary valve 14 and the like are connected. Furthermore, the output circuit 34 is connected to an abnormality monitor lamp 38 and a display 39 for displaying various types of information.

40 is an air volume adjustment circuit 40 connected to the CPU 25 and for adjusting the amount of combustion air supplied to the burner IO;
An air conditioning fan 41 for adjusting air volume and a flame sensor 42 provided in the combustion section of the burner 10 to detect the flame state are connected.

Next, an example of control processing of the burner ignition process in the embodiment of the present invention configured as described above will be explained as shown in FIGS. 3 and 4.
This will be explained with reference to the figures.

First, turn on the drying switch located in the operation switch section 26.
When it is N (step S1), the fuel pump 23, the ignition heater 34, the exhaust fan motor 35, the valve motor 37, and other poday motors are started (step S2), and at the same time, the temperature TO measured by the hot air temperature sensor 22 is detected. (Step S3).

Next, step S4) opens the fuel valve 24.
As shown in FIG. 3, after a first time t1 has elapsed from that point, it is determined whether there is a detection signal from the frame sensor 42 (step S5).

As a result of the determination, if the detection signal from the flame sensor 42 is in the ON state as shown by the dotted line in FIG. 3, the burner IO has ignited, and the process moves to the next combustion process (step S6).

On the other hand, as a result of the above determination, when the detection signal from the flame sensor 42 is in the OFF state as shown by the solid line in FIG. Detect (step S7).

Next, this measured temperature TI and the previously detected measured temperature To
and compare this temperature difference (step S
8. As a result of the comparison, if the temperature difference is 3°C or less, it is considered that there is no possibility of ignition of the burner 10, so it is assumed that an ignition error has occurred and abnormality processing is performed (Step 5I).
O).

Further, when the temperature difference is 8° C. or more, it is considered that the burner 10 is lit but in a red flame state, so the second time t2 is set to 30 seconds as shown in FIG. 5ll).

Furthermore, when the temperature difference is in the range of 3°C to 8°C, it is considered that air gets mixed into the fuel supply pipe due to the burner 10 turning on and off, and ignition is possible after some time has passed. The time t2 is set to 15 seconds (Step 2 512).

At the point in time when the second time t2 has elapsed, the presence or absence of the detection signal from the flame sensor 42 is determined, and if the detection signal is ON as shown by the solid line in FIG. 3, the process moves to the next combustion process.

On the other hand, when the detection signal from the flame sensor 42 is OFF, it is assumed that the burner 10 has ignited incorrectly, and abnormality processing is performed.

Next, a control example will be described in which the first embodiment of the present invention is delivered and installed to a user and the test run mode is set to perform a test run.

In this case, for example, as shown in Figure $5, when the drying switch is pressed while the buzzer stop switch provided on the operation switch section 26 is pressed, the trial run mode is set and operation in that mode is started.

Then, at the same time, only the fuel pump 23 and the fuel valve 24 are driven, and this driving continues for a predetermined time t3, for example, three minutes.

At this time, the ignition motor 34 is inactive and the burner 10
The combustion section does not burn, and the fuel supply pipe is filled with fuel, so the air in the fuel supply pipe escapes.

Thereafter, the fuel pump 23 is driven again, and at the same time, the ignition heater 34, exhaust fan motor 35, etc. are driven, and the process shifts to a normal drying process.

In this way, when operating in the test run mode, if the air in the fuel supply pipe of the burner 10 is removed through the step of removing air at the beginning of the operation and then the drying step is started, the air release in the test run mode can be automated and the ignition time can be reduced. In addition, it is possible to eliminate the risk of unnecessary energization of the ignition heater and shortening its lifespan.

(Effects of the Invention) As described above, in the present invention, when it is determined that the burner is not ignited based on the detection signal of the flame sensor, the increase change in the temperature detected by the hot air temperature sensor is compared, and the increase change is determined to be a predetermined value. When it exceeds the limit, we re-determine whether or not the eight-stroke is ignited based on the detection signal of the flame sensor.
Even in the case where the red flame state of the burner continues for a predetermined period of time as in the prior art, it is possible to eliminate the drawback that the abnormality is treated as an ignition error.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a dryer embodying the present invention, FIG. 2 is a block diagram of its electrical system, FIG. 3 is a time chart showing a control example of the embodiment of the present invention, and FIG. 4 is a flowchart thereof. FIG. 5 is a flowchart showing an example of control related to the embodiment of the present invention. lO...Burner, 22...Hot air temperature sensor, 25.
...CPU, 42...Frame sensor.

Claims (1)

[Claims] In a grain dryer that dries grain with hot air from a burner and has a hot air temperature sensor that detects the temperature of the hot air from the burner and a flame sensor that detects the flame from the burner, a first time elapsed from ignition of the burner. Later, ignition determination means determines whether the burner is ignited based on the detection signal from the flame sensor, and when the means determines that the burner is not ignited, an increase in the temperature detected by the hot air temperature sensor is set to a predetermined value. a re-judgment instructing means for comparing and outputting a re-judgment signal when the value exceeds a predetermined value; A burner ignition determination device comprising: ignition re-determination means for re-determining whether or not ignition has occurred.