JPH0475970B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method and a measuring device for measuring the amount of gas pumped in a vacuum car, and more particularly, to a method and a measuring device for measuring the amount of gas pumped in a vacuum car. The present invention relates to a method and a measuring device for measuring the amount of pumping in a vacuum car, in which the volume of a space part is known from the pressure change in the part, and the volume of the space part is known from the difference in the volume of the space part before and after pumping.

(Prior art) The measuring device for the amount of sewage pumped in a vacuum car for collecting filth is based on a level gauge installed on the rear of the tank. Since the pumping operation is performed, there is a large display error, and especially since the tank is flat, it is extremely difficult to accurately measure the pumped amount.

In addition, if a general flowmeter or electromagnetic flowmeter is installed in the waste intake route, it should be possible to directly calculate the amount pumped, but in reality, this is inappropriate because paper waste, foam, etc. are mixed in. .

(Objective of the Invention) An object of the present invention is to provide a measuring method and device capable of quickly and accurately measuring the amount of water to be pumped, while eliminating the drawbacks of the above-mentioned conventional techniques.

(Structure of the Invention) The present invention provides a pressure sensor facing the upper space of a tank of a vacuum car for pumping out filth, and further provides a communication path communicating with the outside air from the upper space of the tank via a pump and a flow rate sensor. The amount of waste collected is measured using a volume measuring device in the upper space.

The measurement method is to let air flow into the upper space of the tank, or let air flow out from the upper space.
The volume of the space is determined from the amount of air flowing in and out and the change in pressure within the upper space.

By measuring the volume of the space before and after pumping, the amount of pumping can be calculated from the difference.

In addition, an auxiliary tank is installed in the main tank of the vacuum car so as to communicate with the upper space, and after the pressure of both tanks is measured with the communication cut off, the common pressure is measured and calculated by connecting both tanks. The volume of the upper space is determined by , and the volume to be pumped is measured from the difference in volume between the upper space before and after pumping.

In either case, the information obtained from each sensor can be calculated by a microcomputer, the amount can be displayed, and it can also be printed on a recording sheet.

Now, as a method of calculation by changing the pressure by moving air in and out of the upper space of the tank, if the volume of the tank is V, the load inside the tank is Vx, and the volume of the upper space is Vy, then V = Vx + Vy Now Vy If the pressure at a volume of Then, (V1+ΔV1)=(P1+ΔP1)Vy...(2) Substitute (1) into (2), P1Vy+ΔV1=P1Vy+ΔP1×Vy ∴Vy=ΔV1/ΔP1...(3) Here, the air before and after pumping If the inflow and outflow amount and pressure change are respectively (ΔV1, ΔV2) and (ΔP1, ΔP2), then ΔVy=ΔV2/ΔP2−ΔV1/ΔP1 Therefore, the pumping amount ΔVx is, ΔVx=−ΔVy=−(ΔV2/ΔP2 −
ΔV1/ΔP1) = ΔV1/ΔP1−ΔV2/ΔP2……(4) Next, when measuring by communicating the upper space of the main tank with the auxiliary tank, the volume of the main tank is V _M and the volume inside the tank is The load capacity is Vx, the volume of the head space is Vy, the volume of the auxiliary tank is Vs, and with the communication between both tanks cut off, the pressure in the head space is
Py1, the pressure of the auxiliary tank is Ps1, and the pressure when both tanks are then communicated is P1, then V _M = Vx + Vy Py1Vy + Ps1Vs = P1 (Vy + Vs) (Py1 - P1) Vy = (P1 - Ps1) Vs Vy = P1 −Ps1/Py1−P1・Vs ……(a) Using the above formula, find the volume of the upper space V _y 〓, V _y 〓 before and after pumping, and the amount to be pumped is ΔVx＝V _y 〓−V It can be found by _y 〓.

(Example) Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a state in which a weighing device according to the present invention is attached to a vacuum car.

Reference numeral 1 denotes a metering device, which is connected to a manhole 12 provided at the top of the vacuum tank 10 and communicates with the outside air via a vacuum pump 14.

Reference numeral 16 denotes a suction/exhaust switching valve, which is interposed between the metering device 1 and the vacuum pump 14 and mainly sucks the load into the vacuum tank 10 or controls the tank 10.
and when operating the metering device 1.

FIG. 2 shows an enlarged view of the weighing device 1. As shown in FIG.

2 is a pressure gauge, 3 is an integrating flow meter and a measuring inflow solenoid valve, and 5 is a vacuum stop electric valve, each of which is installed in a pipe 6 that communicates from the manhole 12 to the vacuum pump 14, and is connected to the integrating flow meter 3. A press-fit pipe 7 from a vacuum pump 14 is in communication.

Vacuum tank 10 using this measuring device 1
To measure the volume of the upper space of , close the electric valve 5, open the solenoid valve to introduce outside air from the press-fit pipe 7, and return the pressure to 210 mmHg. At that time, assume that the integrated flow meter 3 indicates a flow rate of 40, as described in (3) above. From the formula, Vy = ΔV1 / ΔP1 = 40 / 200 / 760 = 152 If the volume of the upper space before pumping is 152, and when measured in the same way after pumping, it becomes 50, then the pumping volume is 152 - 50 = 102. Become.

The volume of the upper space before pumping and after pumping and the subtraction pumping amount are calculated by a microcomputer and displayed digitally on the control panel, and a bill of charge may be printed as necessary.

In addition, the amount pumped out is accumulated and stored, allowing you to know the progress until it is fully loaded, and the total capacity at the time of unloading. In addition, when the upper space of the tank is reduced to about 1/3 of the total, the calculation correction function is activated, and the pumping amount is adjusted based on the tank-specific correction value based on the loading amount before each pumping operation. You can also ask for it.

In this embodiment, outside air was introduced at the time of measurement, but it is also possible to further suction and discharge the air in the vacuum tank 10 for measurement.

Next, another embodiment will be explained with reference to FIG.

Reference numeral 20 denotes a sub-tank for measurement, which communicates with the pipe 6 via a stopper valve 21 and with the outside air via a stopper valve 22.

Now, with the conduction valve 5 closed, if you close the stopper valve 21 and open the stopper valve 22, the sub-tank 20 will match the external pressure, and then close the stopper valve 22 and open the stopper valve 21. When opened, the pressures in the sub tank 20 and the main tank 10 become equal.

For example, if the pressure in the main tank 10 is 10 mmHg, the pressure in the sub tank 20 is 760 mmHg, the volume is 20, and the pressure in both tanks becomes 210 mmHg after opening the stopper valve 21, then the main tank 1
The volume Vy of the upper space at 0 is calculated from equation (a) above: Vy = 210-760/10-210 x 20 = 50 In this way, the amount pumped can be measured and displayed in the same way as in the previous example. .

Note that if a pressure gauge that can measure the pressure inside the sub-tank 20 is provided, the pressure in the sub-tank 20 can be set to a pressure different from the internal pressure of the main tank 10 without having to communicate the pressure in the sub-tank 20 with outside air to bring it to normal pressure before connecting both tanks. If so, measurement can be performed at an appropriate pressure.

(Effects of the Invention) According to this invention, it is possible to accurately grasp the amount of water pumped in the pumping work, which has not been possible in the past, and it can be easily displayed as a calculation form, etc., which will satisfy the general public. This will further increase trust and contribute to the smooth execution of pumping operations.

Although the present invention has been variously explained above with reference to preferred embodiments, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. It is.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is an overall explanatory diagram of a vacuum car, FIG. 2 is an enlarged explanatory diagram of a measuring device of one embodiment, and FIG. 3 is an enlarged explanatory diagram of a measuring device of another embodiment. It is. 1... Measuring device, 2... Pressure gauge, 3... Integrating flow meter, 4... Solenoid valve, 5... Vacuum stop electric valve, 6... Pipe, 7... Press-fit pipe,
10... Vacuum tank, 12... Manhole, 14... Vacuum pump, 20... Sub tank, 21... Stopper valve, 22... Stopper valve.

Claims (1)

[Claims] 1. By suctioning and discharging the gas in the upper space of the tank of the vacuum car, and knowing the amount of gas discharged and the pressure change in the upper space of the tank, the volume of the upper space of the tank is known, and this volume can be calculated. A method of measuring the amount of water pumped by a vacuum car by measuring before and after pumping. 2. Inject gas into the upper space of the tank of the vacuum car, and by knowing the amount of gas fed and the pressure change in the upper space of the tank, know the volume of the upper space of the tank, and calculate this volume before and after pumping. A method of weighing the volume of vacuum pumping by measuring. 3 Install an auxiliary tank that communicates with the main tank of the Bakyum car and the upper space of this main tank. After cutting off the communication between both tanks and measuring the pressure of each tank, connect both tanks and re-open both tanks. A method of measuring the volume pumped by the vacuum car by measuring the common pressure of the tank, determining the volume of the upper space of the main tank from these pressures and the known volume of the auxiliary tank, and measuring this volume before and after pumping. 4. Provide an auxiliary tank that communicates with the main tank of the Bakyum car and the upper space of this main tank. After cutting off communication between both tanks and bringing the auxiliary tank to outside pressure, connect both tanks and re-open both tanks. A method of measuring the volume pumped by the vacuum car by measuring the common pressure, determining the volume of the upper space of the main tank from these pressures and the known volume of the auxiliary tank, and measuring this volume before and after pumping. 5. A device for measuring the amount of water pumped in a vacuum car, characterized in that a pressure sensor is provided in the upper space of the tank of the vacuum car, and a path communicating with the outside air is provided via a pump and a flow rate sensor. 6. The device for measuring the amount pumped in a vacuum car according to claim 5, wherein the pump is of a gas suction/exhaust type. 7. The device for measuring the amount pumped in a vacuum car according to claim 5, wherein the pump is of a gas feeding type. 8 An auxiliary tank is provided that communicates with the upper space of the main tank of the vacuum car, a pressure sensor is installed in the upper space of the main tank and the auxiliary tank, and a shutoff device is installed in the communication area between the upper space of the main tank and the auxiliary tank. A measuring device for measuring the amount of water to be pumped in a vacuum car. 9. The device for measuring the amount pumped in a vacuum car according to claim 8, wherein the auxiliary tank is made open to the outside air.