JPH0646305Y2 - Automatic fumigant supply device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to an automatic fumigant supply device used in the case of fumigating grains, feed or other substances with methyl bromide or the like for insecticidal purposes.

[Conventional technology]

Conventionally, there is no automated fumigant supply device,
When starting the fumigation work, for example, the main valve of a cylinder containing a fumigant such as methyl bromide was manually opened and closed, and the closing operation was performed by reducing the scale of the weighing machine on which the cylinder was placed to a predetermined weight value. This was done by the operator visually confirming.

In such an automatic fumigant supply device, when the fumigant is completely used up, the inside of the cylinder is opened to the atmosphere, so that air is mixed when the fumigant is filled next time. Therefore, it is necessary to prevent the fumigant in the cylinder from being used up, and to prevent the problem that the fumigant is not supplied due to the main valve of the cylinder being closed at the start of dosing, a pressure switch is attached to the pipe. It is conceivable to install a flow meter or a flow meter.

That is, by measuring the pressure in the pipe by the pressure switch, or by monitoring the flow rate of the fumigant in the pipe by a flow meter, the pressure drop in the cylinder, or the flow rate decrease in the pipe is detected and The main valve or the valve should be closed so that
While not using all fumigant in the cylinder, monitor the pressure in the pipe with a pressure switch for a few seconds after the start of dosing, and monitor the flow rate in the pipe with a flow meter (in this case, the pressure switch and the flow rate). (In addition to the meter, a timer is also required.) If there is no pressure increase or flow rate increase, it is judged that the main valve of the cylinder is closed, and the required fumigation is automatically performed without much human intervention. It is thought possible to do.

[Problems to be solved by the device]

However, in the case of the above configuration, members such as a pressure switch, a flow meter, and a timer are required, the number of parts increases, the configuration becomes complicated, and the cost increases. Further, the pressure switch, the flowmeter, etc. generally have a large error with respect to the set value, and it is not easy to change the set value, and it is difficult to make fine setting.

In addition, a fumigant liquefied under high pressure conditions is often used, and in this case, the vaporized fumigant is at a constant pressure while the liquid substance is present in the cylinder, and the pressure immediately decreases when the liquid substance disappears. And a decrease in flow rate will occur. Therefore, control by pressure or flow rate may be difficult.

The present invention has been made in consideration of the above matters, and its purpose is to detect the remaining amount of fumigant in the cylinder without requiring members such as a pressure switch, a flow meter and a timer. Alternatively, an object of the present invention is to provide an automatic fumigant supply device capable of smoothly supplying the fumigant without exhausting the fumigant, and capable of performing fine setting.

[Means for Solving the Problems]

In order to achieve the above object, an automatic fumigant supply device according to the present invention is provided with a cylinder containing fumigant inside, a main valve of the cylinder, a pipe connected to the main valve, and a pipe connected to the main valve. A valve, a weighing scale for detecting the weight of the cylinder, and a detection signal from the weighing scale are received to determine a weight reduction rate, and when the reduction rate is lower than a preset value stored in advance. A controller that sends a control output for closing the valve and that can arbitrarily set the set value is provided.

[Action]

According to the above configuration, the reduction amount of the cylinder weight is constantly monitored,
By confirming that the decrease rate has decreased, it is possible to detect that the amount of fumigant in the cylinder has decreased, and when the decrease rate is below the set value, the controller closes the valve and Is prevented from being emptied, and the problem that the fumigant cannot be supplied because the main valve of the cylinder remains closed at the time of starting the supply of the fumigant is prevented.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the present invention, in which 1 is a cylinder mounted on a weighing scale 2 in which a fumigant such as methyl bromide is contained. There is. Then, the scale 2 measures the total weight of the cylinder 1 and the fumigant in the cylinder 1, and inputs the weight signal a via the signal cable 3 to the controller 8 provided in the control device 7 described later. It is configured as follows.

Reference numeral 4 denotes a pipe which is detachably connected to a cylinder main valve (main valve) 5 of the cylinder 1, which is provided with a valve 6 which is an electromagnetic valve, and the other end of which is connected to a vaporizer (not shown). In this embodiment, the pipe 4 is provided so as to pass through the control device 7, and the valve 6 is provided in the control device 7.

The control device 7 includes a controller 8 which internally operates based on a program and various inputs, outputs a control signal, or stores data. Further, the input keys 9 and the display window 10 are provided on the upper surface of the control device 7.
An operation panel unit 12 having a display unit 10 including a and a display lamp 10b, a printout unit 11, and the like is formed. The valve 6 is controlled by the control signal b from the controller 8.
The opening degree is controlled by.

Thus, in the automatic fumigant supply device having the above configuration, when the input key 9 is operated to set the dosage, the dosage start button is pressed and the dosage start command c is input,
A control command (valve open command) b is output from the controller 8, and the valve 6 is brought into a predetermined open state.

By the way, the weight signal a is sent from the weighing scale 2 to the controller 8
Since it is always input to, the open / closed state of the cylinder base valve 5 can be detected by checking the weight reduction rate (eg, g / sec) at the start of the medication.

That is, when the valve 6 is in the predetermined open state, if the cylinder base valve 5 is in the open state, the weight reduction rate is equal to or higher than the set value, but if the cylinder base valve 5 is in the closed state or almost the same. This is because the speed of weight reduction becomes less than or equal to the set value when it is not open. Therefore, when the weight reduction speed is less than or equal to the set value, the controller 8 outputs a control command (valve closing command) b to close the valve 6 (or a separately provided opening / closing valve) and the cylinder base valve 5
The fact that is not in a predetermined open state is displayed by the display window 10a and the display lamp 10b, or a message is output by the printout unit 11. In addition, the change of the above-mentioned set value is arbitrary.

Then, when the valve 6 is in a predetermined open state and the cylinder base valve 5 is properly opened, the fumigant in the cylinder 1 passes through the valves 5 and 6 and flows in the pipe 4 to the right side in FIG. It flows out toward the side and a predetermined fumigation is performed. Then, the fumigant inside the cylinder 1 decreases as the fumigation work continues, and the weight change of the cylinder 1 during that time is grasped by the weight signal a being constantly input from the weighing scale 1 to the controller 8. Since the weight reduction rate decreases as the remaining amount of the fumigant decreases, when the weight reduction rate becomes equal to or less than the set value, the controller 8 issues a control command (valve closing command). b
To output valve 6 (or an on-off valve that was separately provided)
While closing, the display window 10a and the display lamp 10b indicate that the fumigant in the cylinder 1 is running low, or a message is output by the printout section 11.

[Advantages of the Invention] As described above, according to the present invention, the controller can detect the remaining amount of the fumigant in the cylinder or smoothly perform a predetermined medication, and the controller can be used. Since the reduction rate of the cylinder weight for closing the valve can be arbitrarily set by the above, fine control can be performed and a wide range of flow rates can be supported.
Moreover, since members such as a pressure switch, a flow meter and a timer are not used, the number of parts is small and the cost can be reduced.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention. FIG. 1 is a schematic view of a main part of an automatic fumigant supply device, and FIG. 2 is a perspective view thereof. 1 ... Cylinder, 2 ... Weighing scale, 4 ... Piping, 5 ... Cylinder main valve, 6 ... Valve, 8 ... Controller, a ...
... weight signal, b ... control signal.

Claims (1)

[Scope of utility model registration request] 1. A cylinder containing a fumigant therein, a main valve of the cylinder, a pipe connected to the main valve, a valve provided in the pipe, and a weighing scale for detecting the weight of the cylinder. And receiving a detection signal from the weighing scale, and determining the speed of decrease of the weight, and when the speed of decrease is lower than a preset value stored in advance, sends a control output for closing the valve, And an automatic fumigant supply device, characterized in that it is provided with a controller capable of arbitrarily setting the set value.