JPH0146400B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid receiving method and apparatus for receiving liquid in a mobile tank such as a tank truck or a tank wagon into a storage tank or the like.

Conventionally, as a device for receiving liquid from a tank truck (mobile tank), the suction side of an unloading pump (transfer pump) is connected to a header equipped with a plurality of continuous piping in parallel via pump suction side piping. A storage tank was connected to the discharge side of the dengue pump via a discharge pipe, and an air separation device (dump tank) that allowed the liquid inside the tank truck to flow down by gravity was connected to the above-mentioned pump suction side pipe via an inlet pipe and an outlet pipe. This is known (Japanese Unexamined Patent Publication No. 55-38266).

This liquid receiving device has multiple connecting pipes connected to the unloading pump via a header, so multiple tanker trucks can be connected to the connecting pipes and the liquid loaded on the tanker truck can be received into the storage tank at the same time. However, it is not possible to directly suck the liquid from the tanker truck and simultaneously suck the liquid in the air separation device from the outlet pipe.

In other words, even if you open the valves on the bypass pipe and outlet pipe on the pump suction side piping, the unloading pump will only suck liquid from the pump suction side piping, which is a piping system where liquid can easily flow. The liquid inside the tank truck is difficult to flow toward the unloading pump through the outlet pipe coming out of the air separation device located lower than the unloading pump, and the liquid inside the air separation device is not sucked. Therefore, there is a problem that the liquid receiving operation cannot be carried out continuously and efficiently.

The first invention allows the liquid in the mobile tanks, whose liquid level has dropped, to naturally flow down to a dump tank provided at a lower position than the mobile tanks, after the liquid in the mobile tanks is directly sucked from the plurality of mobile tanks by the transfer pump means of the fluid transfer means. In a method for receiving liquid from a mobile tank, the flow rate of the fluid transfer means is controlled according to the number of mobile tanks directly sucked by the transfer pump means connected to the fluid transfer means, and the liquid in the dump tank exceeds a predetermined liquid level. The second aspect of the present invention is characterized in that, in the above-mentioned case, control is performed to ensure that a predetermined amount of liquid is transferred from the dump tank by a part of the transfer pump means, giving priority to the flow rate control of the direct suction. , a transfer pump means having a plurality of pumps, a dump tank provided at a position lower than the moving tank, a moving tank suction channel provided on the suction side of the transfer pump means, and dropping liquid into the dump tank. a drop-in flow path, a plurality of selection means provided at the connection portion of the movable tank suction flow path and the drop-in flow path for selecting both flow paths, switch means provided in correspondence with the number of said selection means; liquid level detection means for detecting a predetermined liquid level in the tank;
A dump tank suction flow path for sucking the liquid in the dump tank from the dump tank by the transfer pump means, and a part of the moving tank suction flow path is switched to a dump tank suction flow path to flow the dump tank suction flow. a switching means for communicating the passage with a part of the pump of the transfer pump means; a discharge passage including a flow rate transmitter and a flow rate regulating valve and communicating with the discharge side of the transfer pump means; The number of selecting means in communication with the mobile tank suction flow path is counted, and the standard received flow rate based on the above counting result is compared with the flow rate information emitted from the flow rate transmitter, and the flow rate information of the flow rate transmitter is added to the received flow rate. Adjust the opening of the flow control valve so that the
When the liquid level detecting means detects the predetermined liquid level of the liquid in the dump tank, the switching means preferentially connects the dump tank suction flow path and the pump to connect the dump tank to the dump tank. The third invention further provides a transfer pump means having a plurality of pumps, and a dumper provided at a position lower than the moving tank. A tank, a movable tank suction channel provided on the suction side of the transfer pump means, a dropping channel for dropping liquid into the dump tank, and a connecting portion between the movable tank suction channel and the dropping channel. a plurality of selection means for selecting both flow paths; switch means provided corresponding to the number of said selection means; liquid level detection means for detecting a predetermined liquid level in said dump tank; A dump tank suction channel for sucking the liquid in the dump tank by the transfer pump means, and a part of the movable tank suction channel is switched to a dump tank suction channel, and the dump tank suction channel is connected to the transfer pump. The number of switching means communicating with a part of the pumps of the means and the selection means communicating with the mobile tank suction flow path by the switch means is counted, and the number of operating pumps of the transfer pump means is determined based on the counting result. and when the liquid level detection means detects the predetermined liquid level of the liquid in the dump tank, the switching means preferentially connects the dump tank suction flow path and the pump. The above-mentioned conventional problems have been solved by providing a control means for causing the liquid in the dump tank to be sucked by the pump.

In the figure, 1 is a storage tank installed above ground;
2 is a dump tank installed underground, 3a, 3b
4 is a transfer pump, and 4 is a control panel that controls the operation of the entire receiving device. 5 is a tank truck,
It is usually divided into 3 to 5 conversions by partitions and has an outlet valve 5a.

In the receiving part 6 of this liquid receiving device,
A main valve 8 is provided with a limit switch 8a that turns on when opened, and a flexible hose 7 is connected to the inlet side of this main valve 8, and an automatic three-way valve 9 is connected to the outlet side. 9
A limit switch 9a, which will be turned on when switched to the piping _A1 side, which will be described next, is installed.

One of the outlets of this automatic three-way valve 9 is connected to the header pipe 10 by pipe A ₁ , and the other outlet is connected to pipe A 1.
It is connected to the header pipe 11 at _B1 . In addition,
A plurality of receiving parts 6 are provided so that a plurality of tank trucks 5 can be connected at the same time, and all of them are connected to header pipes 10 and 11 in parallel. The header pipe 10 is connected to the transfer pumps 3a and 3b by a pipe _A2 , and the header pipe 11
is connected to dump tank ₂ via pipe B2.
Also, the pipe C from the dump tank 2 is connected to the transfer pump 3.
It is connected to the pipe A ₂ near pipes a and 3b. Note that the system including the pipes A ₁ and A ₂ is referred to as a tank direct reception system, and the system including the dump tank 2 and pipe C is referred to as a dump tank transfer system.

Further, the transfer pumps 3a, 3b and the storage tank 1 are connected by two lines of piping D ₁ , D ₂ and a piping D that joins these lines. A flow rate transmitter 12b and a flow control valve 12 are sequentially provided in the piping _D1 of one system, and a flow rate limiting orifice 17 is provided in the piping _D2 of the other system.

In addition, the transfer pumps 3a and 3b have bypass pipes _E1 and _E2 that bypass the pipes on the suction side and the discharge side,
Each of the bypass pipes E ₁ and E ₂ is provided with a bypass valve e ₁ and e ₂ , respectively. This bypass piping E ₁ ,
E ₂ is the bypass valve e ₁ , if air gets mixed in the tank direct reception system or dump tank transfer system.
e ₂ is opened and static pressure is applied to the storage tank 1, and air is pumped through pipe C or sequentially into pipe A ₂ , header pipe 10, and pipes.
A ₁ , automatic three-way valve 9, piping B ₁ , header pipe 11,
It exits from the dump tank 2 via piping B ₂ .

Furthermore, a level switch 13 is provided in each lorry tank to detect a certain water level when the content liquid is nearly empty and to issue a signal for operating the pump and changing the flow rate. This level switch 13
It is a compact ultrasonic or capacitive type, and is usually wound on a reel and attached to the roof above the loading area, and when the lorry arrives, it is pulled down and the compartment is the first to be emptied. It is possible to consider a method such as setting it within the range (which one is emptied first is determined by the lorry).

A level switch 14 is also set in the dump tank 2 to detect high and low levels of the liquid level. In addition, automatic valves 15a 1 and 15b 1 are provided in the piping A ₂ of the lorry direct receiving system, and automatic valves 15a ₂ and 15b ₂ are provided in the piping C of the dump tank transfer system, corresponding to the pumps _3a and _3b , respectively. Similarly, automatic valves 16a ₁ and 16 are installed in the pipe D ₁ system.
Automatic valves 16a ₂ and 16b ₂ are provided in the systems of b ₁ and piping D ₂ , and are opened and closed in response to signals from the control panel 4 to switch between the above-mentioned systems. These automatic valves 16a ₁ , 16b ₂ , 16b ₁ ,
A limit switch (not shown) is attached to _16b2 , which turns on when closed. moreover,
As shown in FIG. 2, the control panel 4 includes a counter circuit 18a that counts the number of ON signals of the limit switches 9a attached to the automatic three-way valves 9 corresponding to the number of receiving tank trucks, a circuit that operates the automatic valves and pumps, etc. Sequence box 1 containing
8, a resistance box 19 that changes the resistance value in accordance with the number of receiving tank trucks counted by the counter circuit 18a, and a control reference signal that controls the receiving flow rate from the receiving tank truck as a voltage to the cascade type flow rate regulator 12a. and a constant current oscillator 20 that causes a current to flow through the resistance box 19 for the purpose of supplying the current to the resistor box 19.

Next, the operation of the above-mentioned liquid receiving device will be explained along with the operating method, divided into two parts: receiving from a tank truck and transferring from a dump tank to a storage tank.

() Acceptance from tank truck (1) Automatic valves 15a ₁ , 15b ₁ , 16a ₁ , 16b ₁ on the suction side and discharge side of pumps 3a and 3b are operated by operating push buttons (not shown) attached to sequence box 18 of control panel 4. ).

(2) Outlet valve 5a of each arriving tank truck 5
The flexible hoses 7 of each receiving portion 6 are arbitrarily connected to the respective receiving portions 6.

(3) Set the level switch 13 for each tank truck. At this time, there is sufficient liquid content, so this level switch 13 is turned on.

(4) Next, open the main valve 8 by hand. Then, the limit switch 8a attached to the valve
It becomes ON.

(5) When the conditions for ON of this limit switch 8a and ON of the level switch 13 are met,
After a certain period of time (several seconds), a timer (not shown) in the sequence box 18 switches the automatic three-way valve 9 so that the liquid flows from the tank truck side to the piping _A1 side. At this time automatic three-way valve 9
Limit switch 9a is turned ON. If the conditions are not met, the automatic three-way valve allows liquid to flow from the tank truck side to the dump tank 2.

(6) After a certain period of time, one transfer pump 3a is activated by the ON signal of this limit switch 9a, and a timer (not shown) of the sequence box 18 is activated.
and giving a control reference signal corresponding to the received flow rate per tank truck to the flow rate controller 12a, and comparing the signal of the flow rate transmitter 12b indicating the flow rate of the pipe D with the control reference signal. Total 12
At step a, the flow rate control valve 12 is adjusted in a cascade manner, and the amount flowing through the pipe D is set as the accepted flow rate per lorry.

(7) After that, when the number of tank trucks increases, the limit switch 9a of the automatic three-way valve 9 of the newly connected tank truck is turned on.
Then, the flow rate controller 1 changes depending on the number of ON signals.
The setting of the control reference signal to 2a is changed, and the flow rate control valve 12 automatically controls the flow rate so that the received flow rate corresponds to the number of tank trucks. That is, this flow rate control is performed by the limit switch 9a of each automatic three-way valve.
A resistance box 19 that counts the number of ON signals by a counter circuit 18a in the sequence box 18, outputs a relay output according to the required flow rate, and changes the resistance according to the relay output.
A current is applied from a constant current transmitter 20 to obtain an output voltage corresponding to the set flow rate, that is, a control reference signal. Then, the control reference signal is used as a cascade signal of the flow rate controller 12a,
This is control to adjust the opening degree of the flow rate regulating valve 12. (See Figure 2) (8) When the number of tank trucks reaches a preset number, the second pump 3b is activated. That is, the counter circuit 18a counts the number of ON signals of the limit switch 9a of each automatic three-way valve 9, and as shown in the relationship shown in FIG. A start signal is issued.

The starting priority order of the pumps 3a and 3b is as follows:
It is also possible to make the operating times of the pumps 3a and 3b uniform by making it possible to switch the start signal from the sequence box 18 to each pump using a switch or the like.

(9) When the liquid level inside the tank truck decreases and reaches the preset water level just before it becomes empty, the level switch 13 turns OFF and the automatic three-way valve 9 switches to the pipe B1 of the dump tank ₂ ~. The remaining liquid in the lorry tank flows into the dump tank 2 by natural flow due to gravity. Further, as described above, when the automatic three-way valve 9 switches to the pipe _B1 to the dump tank 2, the limit switch 9a is turned off at the same time, and the opening degree of the flow rate control valve 12 and the number of pumps in operation are changed.

() Transfer from the dump tank to the storage tank (1) When the liquid level rises due to the inflow into the dump tank 2 and reaches a high level, the level switch 14
detects this and sends a signal to the sequence box 18 in the control panel 4. Now transfer pump 3
Assuming that two transfer pumps a and 3b are in operation, the automatic valve 16b ₁ on the discharge side of one transfer pump 3b is activated from the sequence box 18 in response to the above signal.
When the close signal is issued, the sequence box 18 changes the control reference signal to the flow rate controller 12a so that the control reference signal does not exceed the discharge capacity flow rate per pump. As a result, automatic valve 16b ₁ closes.
The flow rate control valve is controlled to a flow rate equivalent to one pump, and one transfer pump 3a continues to receive liquid from the tank truck.

(2) When automatic valve 16b ₁ closes, automatic valve 16b ₁
The limit switch in the
Pump 3b stops under the ON condition, and then automatic valve 1 of the tank direct intake system on the pump suction side
5b ₁ closed, dump tank transfer system automatic valve 1
_5b2 and the automatic valve _16b2 of the pipe _D2 system are opened. Therefore, this transfer pump 3b
The suction side is switched from the tank direct reception system to the dump tank transfer system, and the discharge side is also switched from the piping D ₁ system where the flow rate control valve 12 is located to the piping D ₂ system where the orifice 17 is located.

(3) The above automatic valves 15b ₁ , 15b ₂ , 16b ₁ , 1
When the switching of the pump _6b2 is completed, the pump 3b, which has been temporarily stopped, is started again, and the liquid in the dump tank 2 is transferred to the storage tank 1.
In this case, the flow from the dump tank 2 caused by the pump 3b is not adjusted by the flow rate control valve 12, but is simply controlled by the orifice 1.
7 only limits the transfer flow rate to below the maximum flow rate per pump.

(4) When the liquid level in the dump tank 2 drops to a low level, the level switch 14 detects this, the transfer pump 3b stops, and the electric valves 15b ₁ , 15b ₂ , 16b ₁ , 16b ₂ are turned on again. is switched to its original state, and the two transfer pumps 3a, 3
At step b, the liquid is returned to the normal liquid receiving control of directly receiving the liquid from the tank truck.

(5) In the above, when the liquid level in the dump tank 2 reaches a high level when originally only one transfer pump 3a was used to receive directly from the tank truck, the automatic valves 15a ₁ , 15b ₁ ,
16a ₁ , 16b ₁ open, automatic valves 15a ₂ , 15
Since b ₂ , 16a ₂ , and 16b ₂ are closed,
Close automatic valves 16b ₁ and 15b ₁ , 16b ₂ and 15b ₂
Transfer pump 3b that is open and not operating
The contents of the dump tank 2 are transferred to the storage tank 1. At this time, the control reference signal to the flow rate controller 12a is suppressed by the sequence box 18 so that the flow rate does not exceed the discharge capacity flow rate per pump 3a. In addition, in this embodiment, in the case of transferring from the dump tank 2 to the storage tank 1, the transfer using the system of pipe C, automatic valve 15b ₂ , pump 3b, automatic valve 16b ₂ and pipe D ₂ has been described. Replaced with piping C, automatic valve 15a ₂ , pump 3
Of course, the sequence of transferring from the dump tank 2 to the storage tank 1 can be made by using the system of A, automatic valve 16a ₂ , and piping D ₂ . Also, in place of orifice 17, pipe _D1
A flow rate transmitter, a flow rate control valve, and a flow rate control meter similar to those provided in the above may also be provided separately. Furthermore, by using the above-mentioned combination, the number of pumps can be increased to three or more.

In the above embodiment, the switch means is the limit switch 9a, the transfer pump means is the two transfer pumps 3a and 3b, the suction flow path of the moving tank is the pipe _A1 , the header pipe 10, and the pipe _A2 , and the discharge flow is The path is the pipe D ₁ , the flow rate transmitter 12b, the flow rate control valve 12, the pipe D ₂ , the orifice 17, and the pipe D,
Furthermore, the control means includes a control panel 4 and a flow rate controller 12.
In a, the fluid transfer means is the transfer pump means, the suction channel, the discharge channel, and the valve 8 (receiving part 6), and the switching means is the automatic valves 15a ₁ , 15b ₁ , 15a ₂ , 15b ₂ , 1
6a ₁ , 16b ₁ , 16a ₂ , 16b ₂ , the selection means is the three-way valve 9, and the falling flow path is connected to the pipe B ₁ , the header pipe 11,
Piping B ₂ is the dump tank suction flow path, and piping C is
The liquid level detection means is composed of a level switch 14, respectively.

Incidentally, it goes without saying that the control means of the present invention may be constituted by a computer. In addition, although the limit switch 9a was used as a switching means, it can be used as a limit switch 8a or a level switch 13.
It may be used to indirectly indicate that the movable tank suction flow path and the selection means are in communication, or it may be a manually operated button switch or the like. It goes without saying that the selection means and switching means may be a combination of two-way valves or a three-way valve.

As explained above, the first invention provides a dump tank provided at a position lower than the moving tanks to transfer the liquid in the moving tanks whose liquid level has decreased after the liquid is directly sucked from a plurality of moving tanks by the transfer pump means of the fluid transfer means. In this method, the flow rate of the fluid transfer means is controlled according to the number of movable tanks directly suctioned by the transfer pump means connected to the fluid transfer means, and the liquid in the dump tank is kept at a predetermined level. By adopting a configuration that performs control to ensure that a predetermined amount of liquid is transferred from the dump tank by a part of the transfer pump means, giving priority to the flow rate control of the direct suction when the liquid level exceeds the liquid level. The second invention provides a transfer pump means having a plurality of pumps, a dump tank provided at a lower position than the moving tank, a moving tank suction passage provided on the suction side of the transfer pump means, and a dump tank provided in the dump tank. a dropping channel into which the liquid is dropped, and a plurality of selection means provided at the connection between the moving tank suction channel and the dropping channel for selecting both channels;
switch means provided corresponding to the number of selection means; liquid level detection means for detecting a predetermined liquid level in the dump tank; and liquid level detection means for detecting a predetermined liquid level in the dump tank; a dump tank suction channel for suctioning the moving tank, and a switching means for switching a part of the movable tank suction channel to a dump tank suction channel and communicating the dump tank suction channel to a part of the pump of the transfer pump means; , counting the number of discharge passages that are equipped with a flow rate transmitter and a flow rate control valve and are connected to the discharge side of the transfer pump means, and selection means that are in communication with the moving tank suction passage through the switch means; The standard received flow rate based on the above counting result is compared with the flow rate information emitted from the flow rate transmitter, and the opening degree of the flow rate control valve is adjusted so that the flow rate information of the flow rate transmitter matches the received flow rate. When the liquid level detecting means detects the predetermined liquid level of the liquid in the dump tank, the switching means preferentially connects the dump tank suction flow path and the pump to and a control means for sucking the liquid by the pump,
Furthermore, a third invention provides a transfer pump means having a plurality of pumps, a dump tank provided at a position lower than the moving tank, a moving tank suction flow path provided on the suction side of the transfer pump means, and the dump tank provided at a position lower than the moving tank. A dropping channel for dropping the liquid into the tank, a plurality of selection means provided at the connection between the moving tank suction channel and the dropping channel for selecting both channels, and a plurality of selection means provided in correspondence with the number of the selection means. a switch means, a liquid level detection means for detecting a predetermined liquid level in the dump tank, a dump tank suction channel for sucking liquid in the dump tank from the dump tank by the transfer pump means; switching means for switching a part of the mobile tank suction flow path to a dump tank suction flow path and communicating the dump tank suction flow path to a part of the pump of the transfer pump means; The number of selection means in communication with the passage is counted, and the number of operating pumps of the transfer pump means is adjusted based on the counting result, and the liquid in the dump tank is controlled by the liquid level detection means to reach the predetermined level. A configuration comprising: control means for causing the dump tank suction flow path and the pump to communicate with each other by the switching means to cause the liquid in the dump tank to be sucked by the pump when the liquid level is detected. Therefore, while the liquid in the moving tank is directly sucked by the transfer pump means,
The liquid in the dump tank can be suctioned as needed and the liquid receiving work can be carried out continuously and efficiently without interruption.

[Brief explanation of drawings]

Figure 1 is a system diagram showing the overall configuration of the device for receiving liquid from a mobile tank according to the present invention, Figure 2 is a block diagram showing the configuration of the control panel, and Figure 3 is the number of ON signals from the automatic three-way valve limit switch. FIG. 1...Storage tank, 2...Dump tank, 3
a, 3b...transfer pump, 4...control panel, 5...
Tank lorry, 5a... Outlet valve, 6... Receiving part, 7... Flexible hose, 8... Original valve, 8a... Limit switch, 9... Automatic three-way valve, 9a... Limit switch, 10, 11...
Header pipe, 12...Flow rate control valve, 12a...Flow rate controller, 12b...Flow rate transmitter, 13, 14...
...Level switch, 15a ₁ , 15a ₂ , 15b ₁ , 1
5b ₂ , 16a ₁ , 16a ₂ , 16b ₁ , 16b ₂ ... automatic valve, 17 ... orifice, 18 ... sequence box, 18a ... counter circuit, 19 ... resistance box, 20 ... low current oscillator, A ₁ , A ₂ ,
B ₁ , B ₂ , C, D, D ₁ , D ₂ ... Piping, E ₁ , E ₂ ...
Bypass pipe, e ₁ , e ₂ ... bypass valve.

Claims (1)

[Scope of Claims] 1. After direct suction from a plurality of mobile tanks by the transfer pump means of the fluid transfer means, the liquid in the mobile tanks whose liquid level has decreased is allowed to flow down by gravity to a dump tank provided at a position lower than the mobile tanks. In this method, the flow rate of the fluid transfer means is controlled according to the number of movable tanks directly sucked by the transfer pump means connected to the fluid transfer means, and the liquid in the dump tank is brought to a predetermined liquid level. Liquid reception from a mobile tank, characterized in that when the flow rate exceeds the flow rate control of the direct suction, control is performed to ensure that a predetermined amount of liquid is transferred from the dump tank by a part of the transfer pump means. Method. 2. From the mobile tank according to claim 1, wherein the flow rate of the direct suction in the fluid transfer means is controlled by adjusting the opening degree of a flow rate control valve on the discharge side of the fluid transfer means. liquid acceptance method. 3. The method of receiving liquid from a mobile tank according to claim 1, wherein the flow rate of the direct suction in the fluid transfer means is controlled by adjusting the number of operating pumps of the fluid transfer means. 4. Transfer pump means having a plurality of pumps, a dump tank provided at a lower position than the moving tank, a moving tank suction channel provided on the suction side of the transfer pump means, and dropping liquid into the dump tank. a drop-in flow path, a plurality of selection means provided at the connection portion of the movable tank suction flow path and the drop-in flow path for selecting both flow paths, switch means provided in correspondence with the number of said selection means; a liquid level detection means for detecting a predetermined liquid level in the tank; a dump tank suction channel for sucking liquid in the dump tank from the dump tank by the transfer pump means; and a movable tank suction channel. a switching means for switching a portion of the dump tank suction flow path to communicate the dump tank suction flow path with a portion of the pump of the transfer pump means; a flow rate transmitter; and a flow rate control valve; The number of discharge passages connected to the side and selection means communicating with the movable tank suction passage by the switch means is counted, and the reference acceptance flow rate and the flow rate emitted from the flow rate transmitter are determined based on the counting results. The opening degree of the flow control valve is adjusted so that the flow rate information of the flow transmitter matches the received flow rate, and the liquid in the dump tank is adjusted to the predetermined level by the liquid level detection means. control means for causing the dump tank suction flow path and the pump to communicate with each other by the switching means to cause the liquid in the dump tank to be sucked by the pump when the liquid level is detected; A device for receiving liquid from a mobile tank, characterized by: 5. A transfer pump means having a plurality of pumps, a dump tank provided at a lower position than the moving tank, a moving tank suction channel provided on the suction side of the transfer pump means, and dropping liquid into the dump tank. a drop-in flow path, a plurality of selection means provided at the connection portion of the movable tank suction flow path and the drop-in flow path for selecting both flow paths, switch means provided in correspondence with the number of said selection means; a liquid level detection means for detecting a predetermined liquid level in the tank; a dump tank suction channel for sucking liquid in the dump tank from the dump tank by the transfer pump means; and a movable tank suction channel. switching means for switching a portion of the dump tank suction flow path to communicate the dump tank suction flow path with a portion of the pump of the transfer pump means; and selection of a communication state with the movable tank suction flow path by the switch means. The number of means is counted, and the number of operating pumps of the transfer pump means is adjusted based on the counting result, and when the liquid level in the dump tank is detected to be at the predetermined liquid level by the liquid level detection means. A mobile tank characterized by comprising: a control means for causing the dump tank suction channel and the pump to communicate with each other preferentially by the switching means to cause the liquid in the dump tank to be sucked by the pump. Liquid receiving device from.