JP3012963B2 - Water level control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water level control device applied to a pump operation control for preventing a water level accumulated in, for example, a manhole from rising above a certain level.

[0002]

2. Description of the Related Art In order to prevent the water level accumulated in manholes from rising above a certain level,
2. Description of the Related Art There has been conventionally known a water level control device in which water is drained by a pump activated when the water level reaches a certain level. In such a water level control device, as a means for detecting the water level, there is obtained by employing the methods as disclosed in, JP 2 -268306 JP.
As the water level detection method, as shown in FIG. 4, to no tubular is submerged openings 102 of <br/> cup-shaped container 101, the container 101
The relative pressure ΔP of the space S in the container with respect to the outside atmospheric pressure P is detected by the pressure gauge 103, the depth of submergence h of the container 101 is calculated by the controller 104 using the detected relative pressure ΔP as a factor, and based on the calculated value. This is a method of detecting the water level.

[0003] An arithmetic expression when the above-mentioned water level detection method is employed is h = ΔP ｛(1 / γ) + (L / P + ΔP)｝..., And this expression is derived from the following expressions. . P · L = P1 · L1 P + γh = P1 + γh1 L1 + h1 = L P1-P = ΔP where h is the depth of submergence of the container. h1: Height of the water surface in the container from the lower end of the container P: External pressure P1: Absolute pressure in the space in the container ΔP: Relative pressure L: Length of the size in the container L1: Height of the air layer in the space in the container γ: Water Is the specific gravity of.

[0004] In the above equation, assuming that the external pressure P is 1 atm and the specific gravity γ of water is constant, the length L of the inner dimensions of the container is constant. , Ie, the relative pressure ΔP is measured only.

On the other hand, in the conventional water level control device, when the value calculated by the above equation reaches a value corresponding to the reference water level (starting water level) when starting the pump 105, the pump 105
Is started to start draining, the water level outside the container 101 is lowered, and the calculated value by the above equation is
5 is set to a value corresponding to the reference water level (stop water level) at the time of stopping, specifically, the timer 106 is set when the water level outside the container 101 becomes the submerged depth h = 0 of the container 101,
During the set time, the operation of the pump 105 is continued, and when the time is up, the operation of the pump 105 is stopped. That is, once the drainage is started, the container 101
The process is continued until the outside water level becomes lower than the position of the opening 102.

[0006]

In the conventional water level control device having the above-described structure, when the water level calculation value becomes constant from the pressure change in the container 101, the pump 105 is activated to start draining, and the container 101 is discharged. Since the pump 105 is stopped after the set time by the timer 106 has elapsed from the time when the outside water level has dropped to the level of the opening 102, the amount of water flowing into manholes and the like exceeds the drainage of the pump 105, While the interior of the container 101 is not open to the atmosphere, air enters the container space S, that is, air that enters the enclosed space surrounded by the container wall and the water surface in the container, or the airtightness in the enclosed space is impaired for some reason. If a leak occurs, the absolute pressure P1 of the container space S is changed, previously incorrectly h = 0 the water level outside the container 101 reaches the level of the opening 102 There is to be calculated.

Further, if the set time by the timer 106 continues even after the inside of the container 101 is opened to the atmosphere after the start of drainage , the container 1 will be turned off when the inflow amount becomes extremely small.
The water level outside 01 may be lowered more than necessary, and an undesired situation such as burning may easily occur due to the idle operation of the pump 105.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a water level control device capable of reliably stopping drainage at a predetermined water level by appropriately calculating a water level calculation value based on a change in absolute pressure in a container. It is intended to provide.

[0009]

In order to achieve the above object, a water level control device according to the present invention submerges an opening formed in a cylindrical or bowl-shaped container so that the outside of the container is immersed. the relative pressure in the vessel space calculates the submerged depth of the container as a factor for pressure, the water level controller the calculated value to start draining when it becomes a constant value, the reduction in the water level outside the vessel with the waste water Make sure that the water level in the container is
Le in and those having a controller to stop the drainage when being that <br/> water level variation speed determined from calculated value of submersion depth of the container is 0.

[0010]

According to the present invention, the interior space of the container is sealed when the drainage is continued . Then, even after the drainage is started, even if the inflow exceeds the drainage and air leaks in the container without opening the inside of the container to the atmosphere, the water level change rate is 0, and the water level in the container is equal to the position of the opening. As long as the level is not equal , drainage will continue. Then, when the water level outside the container falls and the water level inside the container becomes the same level as the opening position of the container, and the water level calculation value is 0 and the water level change speed becomes 0, the pump through the controller is used. Drainage is reliably stopped, and therefore, there is no occurrence of burning or the like due to the idle operation of the pump.

[0011]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a water level control device according to one embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a container which is formed in a cylindrical shape or a bowl shape and whose opening 2 is submerged in water W such as in a manhole. It is uniform at each part in the height direction. 3 is a relative pressure Δ of the internal space S with respect to the external pressure P outside the container 1.
A pressure gauge 4 for measuring P receives a measurement output from the pressure gauge 3, detects a water level, activates a drainage pump 5, and controls a drainage operation.

FIG. 2 is a block diagram showing the structure of the controller 4. In FIG. 2, reference numeral 21 denotes the depth of submergence of the container 1 by the above-mentioned equation using the relative pressure ΔP detected by the pressure gauge 3 as a factor. water level calculator for calculating h, 2
Reference numeral 2 denotes a comparator for comparing a water level signal from the water level calculator 21 with a water level set value such as a start water level or a stop water level set in the water level setter 23. Reference numeral 24 denotes a water level change speed calculator which receives a water level signal from the water level calculator 21 and calculates a water level change speed from a temporal change thereof, and 25 denotes a water level change speed from the water level change speed calculator 24 and a water level change speed. This is a comparator for comparing the set value of the water level change speed set in the speed setter 26, and sends a signal to continue the operation of the pump 5 unless the water level change speed becomes 0 after the start of drainage. Reference numeral 27 denotes the comparators 22 and 25 after the drain operation.
Is an AND circuit that takes the logical product of the outputs of the above. The water level change rate is 0, and the water level operation value is 0, that is, the water level in the container 1 is at the same level as the position of the opening 2 of the container 1. When (h = 0), a signal for stopping the operation of the pump 5 is transmitted.

Next, with respect to the operation of the water level control device having the above configuration, the relative pressure ΔP of the container space S, which will be described with reference to the flowchart of FIG.
The detected pressure value is input to the water level calculator 21, and the submerged depth h of the container 1 is calculated by the above-described equation (processing step S31). The comparator 22 determines whether or not the value calculated by the water level calculator 21 has reached the water level set value for pump activation with the rise of the water level outside the container 1 (judgment step S32). When it is determined that the value has reached the water level set value, the pump 5 is started to perform predetermined drainage, and the water level outside the container 1 decreases (processing step S33).

On the other hand, the water level change speed is calculated by the water level change speed calculator 24 in response to the calculated value of the water level calculator 21. Then, by the activation of the pump 5, the drainage is
After the start, the comparator 25 determines whether or not the calculated value of the water level change speed by the water level change speed calculator 24 has become the set value of the water level change speed, that is, 0 (judgment step S34). In the case where the calculated value of the water level change speed is not 0, the operation of the pump 5 is continued and the drainage is continued.

If the calculated value of the water level change speed is 0 in the result of the judgment in the judgment step S34, the container 1
Water level position and the same level of the opening 2 of the container 1 of the inner, i.e.,
It is determined whether the submerged depth h of the container 1 has become 0 (determination step S35). If the result of this determination is that h is not 0, the operation of the pump 5 is continued, and if h = 0, the operation of the pump 5 is stopped and drainage is stopped (processing step S36). ).

As is clear from the above operation flow,
At the time of drainage by the pump 5, if the inflow exceeds the drainage by the pump 5 and air leaks inside the container 1 in a state where the inside of the container 1 is not opened to the atmosphere, the container
Before the outside water level reaches a predetermined level, the water level calculator 2
Although there is a possibility that the calculated value h obtained by the step No. 4 becomes zero, the pump 5 is still operated as long as the water level change rate does not become zero.
Is continued as it is, and a predetermined drainage is performed.

The water level in the container 1 is adjusted to the same level as the position of the opening 2 of the container 1 due to the decrease in the water level due to the drainage.
When the calculated value h is 0 and the water level change rate is 0, the operation of the pump 5 is stopped and the drainage is stopped, so that the water level outside the container 1 is lowered unnecessarily. It is possible to avoid the occurrence of a failure such as burning of the pump 5 due to the idle operation of the pump 5 in the above.

[0019]

As described above, according to the present invention, the submersion depth of the container is calculated by using the relative pressure with respect to the outside air pressure of the space inside the container in which the opening is submerged as a factor, and the depth of the container is adjusted to a predetermined water level value. When the specified drainage is performed after the water level has reached
When the water level in the container reaches the same level as the opening, the drainage is stopped.Therefore, when the inflow is larger than the amount of water discharged by the pump, Even when the pressure changes, it is possible to reliably stop the drainage by the pump at a predetermined water level without being affected by the change in the absolute pressure. Therefore, regardless of the amount of inflow and the presence or absence of air leakage in the container, it is possible to accurately stop the drainage at a predetermined water level and to reliably prevent the occurrence of a failure such as burning caused by the idle operation of the pump. This has the effect.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a water level control device according to one embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a controller of the water level control device in the embodiment.

FIG. 3 is a flowchart illustrating a drainage operation by the controller.

FIG. 4 is a schematic configuration diagram showing a conventional water level control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 2 Opening 3 Pressure gauge 4 Controller 21 Water level calculator 22 Water level change speed calculator ΔP Relative pressure P Atmospheric pressure (outside air pressure outside the container) S Container interior space

Claims (1)

(57) [Claims] An opening formed in a cylindrical or bowl-shaped container is submerged, and a submersion depth of the container is calculated by using a relative pressure of a space in the container with respect to an external pressure outside the container as a factor, and the calculated value is constant. in level control device to start draining when it becomes the value, the lowering of the water level outside the vessel with the waste water
The water level in the container is at the same level as the position of the opening , and the container
Level control apparatus characterized by comprising a controller for stopping the waste water when the water level change rate that is determined from the calculated value of the submerged depth is zero.