JPH0346400B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid receiving device for receiving liquid in a mobile tank such as a tank truck or a tank wagon into a storage tank or the like.

[Conventional technology]

As a conventional device for receiving liquid from a mobile tank, for example, Japanese Patent Application Laid-open No. 55-38266 discloses a header pipe equipped with a plurality of connecting pipes connected in parallel to the outlet pipe of a tank truck through a flexible hose. In addition to being connected to the suction piping on the suction side of the pump, a drop piping is provided that branches from the suction piping to a dump tank (air separation device) located at a lower position than the tank truck. It is described that the liquid in the tank truck is directly sucked in by a pump, and when the liquid level inside the tank lorry is lowered as the liquid level in the tank lorry increases and the possibility of air being pumped is visually observed, the flow path is switched to the dump tank.

[Problem that the invention seeks to solve]

The above liquid receiving device has multiple connecting pipes connected to the transfer pump via a header, so
Although it is possible to connect multiple tank lorry cars to the connection piping and receive the liquid loaded on the tank lorry cars into the storage tank at the same time, no measures have been taken in the case where the reception start times of multiple tank lorry cars are different. cannot efficiently and safely accept liquids.

In other words, when multiple tank trucks are connected to the liquid receiving device and receiving liquid, if even one of them becomes empty and sucks in air, the air will enter the transfer pump and the entire tank truck will not be able to receive the liquid. becomes. Therefore, it is necessary to assign a worker to each tank truck and change the flow path to the dump tank before the tank truck runs out of liquid and sucks in air. Moreover, when some tank trucks visually check the possibility of sucking air and switch the flow path to the dump tank, other tank trucks that do not need to do so must also switch the flow path to the dump tank. Everything flows naturally due to gravity, which takes time.

[Means for solving problems]

The present invention, which solves the above-mentioned conventional problems, will be explained using the reference numerals of the embodiments shown in the drawings.

That is, the present invention provides transfer pump means 3a
, a dump tank 2 provided at a lower position than the mobile tank 5, and a suction channel 1 connected to the plurality of mobile tanks 5 individually and connected to the transfer pump means 3a.
0, A ₂ and the falling flow path 1 to the dump tank 2 above
_A detection signal is generated by detecting that the liquid in the movable tank 5 provided corresponding to each of the plurality of selection means 6 has fallen to a predetermined liquid level. A plurality of liquid level detecting means 13 are provided in communication with each of the liquid level detecting means 13 and each selecting means 6, and when the liquid level detecting means 13 outputs the detection signal, the detection signal is The selection means 6 corresponding to the output liquid level detection means 13 is changed to the previously moving tank 5 and the suction flow path 1.
The configuration includes a control means 4 that switches the communication between _the mobile tank 5 and the drop passage 11 and _B2 from communication with the moving tank 5 and the drop passage 11 and B2.

[Effect]

When the mobile tank reaches a predetermined position, the liquid level detection means is usually set, and the selection means corresponding to the liquid level detection means connects the mobile tank to the suction channel to transfer the liquid in the mobile tank. Suction is made by pump means. Further, when the liquid level detection means detects that the liquid in the movable tank has reached a predetermined liquid level, the control means changes the selection means from the suction flow path to the drop flow path to change the liquid in the movable tank. Let gravity drain into the dump tank.

〔Example〕

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

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 of this liquid receiving device, a main valve 8 equipped with a limit switch 8a that turns on when opened is provided, and a flexible hose 7 is provided on the inlet side of this main valve 8, and an automatic three-way valve is provided on the outlet side. 9 is connected, and this automatic three-way valve 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,
In this embodiment, the main valve 3, three-way valve 9 and piping are
A selection (switching) means 6 is constituted by A ₁ and B ₁ , but even if the content liquid of the tank truck 5 is received by the transfer pumps 3a and 3b, which will be described later, the three-way valve 9 is connected from the piping A ₁ side to the piping B. When switching to side ₁ ,
The three-way valve 9 can close the pipe _A1 without affecting the reception by the transfer pump means from other tank trucks 5, and the tank truck 5 is equipped with an outlet valve 5a. In some cases, the original valve 3 is not necessarily required.

A plurality of selection means 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 the dump tank ₂ by a pipe B2. Also,
Piping C from the dump tank 2 connects to transfer pumps 3a, 3
It is connected to the pipe A ₂ in the vicinity of b.
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.

Furthermore, the transfer pumps 3a and 3b have bypass pipes E1 _{and E2} that bypass the suction side and discharge side pipes, and each bypass pipe _E1 and _E2 has a bypass valve _e1 ,
e ₂ are provided respectively. This bypass piping
E ₁ and E ₂ are the bypass valves if air gets mixed into the tank direct reception system or dump tank transfer system.
e ₁ and e ₂ are opened, static pressure is applied to the storage tank 1, and air is transferred to pipe C or sequentially to pipe A ₂ , header pipe 10,
Piping A ₁ automatic three-way valve 9, piping B ₁ , header pipe 11,
It exits from the dump tank ₂ via piping B2.

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. One possible method is to set the number of containers within the range (which one is emptied first depends on 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 , 16a ₂ , 16
Limit switches (not shown) are attached to b ₁ and 16b ₂ , which are turned on when closed. Furthermore, as shown in FIG. 2, the control panel 4 operates a counter circuit 18a that counts the number of ON signals of limit switches 9a attached to automatic three-way valves 9 corresponding to the number of tank trucks received, automatic valves, and pumps. A sequence box 18 that houses circuits, etc., 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 flow rate received from the receiving tank trucks are connected in a cascade type. The constant current transmitter 20 supplies a current to the resistance box 19 to provide a voltage to the flow rate controller 12a.

In this embodiment, the suction channel is composed of the header pipe 10 and the pipe _A2 , and the drop channel is composed of the header pipe 11 and the pipe _B2 , and the switching means is the limit switch 8a or the limit switch 9a. It consists of

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.

() Receipt 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 pushbuttons (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 section are arbitrarily connected to the respective receiving sections.

(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 3 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 selects the automatic three-way valve 9 to cause liquid to flow from the tank truck side to the pipe _A1 side. At this time, the limit switch 9a of the automatic three-way valve 9 is turned on.
In particular, in this embodiment, if the conditions are not met, the automatic three-way valve 9 is configured to allow 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 9.
A resistance box 1 counts the number of ON signals of the flow rate with 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.
9 is applied with a current 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 regulator 12a, and the opening degree of the flow rate regulating valve 12 is controlled. (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, the automatic three-way valve 9 switches to the pipe B ₁ side 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 is switched to the pipe _B1 side 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 on the
Pump 3b stops under the ON condition, and then automatic branch 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 intake system to the dump tank transfer system, and
The discharge side is also switched from the piping D ₁ system with the flow rate control valve 12 to the piping D ₂ system with the orifice 17 .

(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,
3b accepts directly from tank truck,
The process returns to normal liquid reception control.

(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 , 15
b ₁ , 16a ₁ , 16b ₁ open, automatic valve 15a ₂ , 1
Since 5b ₂ , 16a ₂ and 16b ₂ are closed, automatic valves 16b ₁ and 15b ₁ are closed, and automatic valve 16 is closed.
b ₂ and 15b ₂ are opened, and the liquid content of the dump tank 2 is transferred to the storage tank 1 by the transfer pump 3b which is not in operation. At that time, the flow rate controller 12
The control reference signal to a is pump 3
a Sequence box 18 suppresses the flow rate so that the flow rate does not exceed the discharge capacity per unit.

In addition, in this embodiment, when transferring from the dump tank 2 to the storage tank 1, the pipe C, automatic valve 15b ₂ , pump 3b, automatic valve 16b ₂ ,
Although we have explained the transfer using the pipe D ₂ system, instead of this, it is transferred from the dump tank 2 to the storage tank 1 using the pipe C, automatic valve 15a ₂ , pump 3a, automatic valve 16a ₂ , and pipe D ₂ system. Of course, it can be used as a sequence box. Further, in place of the orifice 17, a flow rate transmitter, a flow rate control valve, and a flow rate control meter similar to those provided in the pipe _D1 may be separately provided. Furthermore, by using the above-mentioned combination, the number of pumps can be increased to three or more.

Furthermore, it goes without saying that the control means of the present invention may be configured by a computer. Further, although the limit switch 8a and the limit switch 9a are used as the switching means, it goes without saying that this may be replaced with a manually operated button switch or the like.

Furthermore, the selection means 6 may be constructed of just two valves in addition to the three-way valve as in the embodiment. The combination of the main valve 8 and the three-way valve 9 in the embodiment can also be configured with one four-way valve or one five-way valve. In the embodiment, the main valve 8 functions as a stand for the above-mentioned manual button switch (functions as a support stand for the limit switch 8a),
It functions as a tool for people to turn on and off, as well as a cap to improve equipment safety and prevent dirt from entering the dump tank.

〔Effect of the invention〕

As explained above, the apparatus for receiving from a mobile tank according to the present invention includes a transfer pump means, a dump tank provided at a position lower than the mobile tank, and a plurality of mobile tanks that are individually connected to the transfer pump means. a plurality of selection means for switching between the suction flow path and the drop flow path to the dump tank; and a plurality of selection means provided corresponding to each of the plurality of selection means so that the liquid in the movable tank has fallen to a predetermined liquid level. A plurality of liquid level detection means for detecting and outputting a detection signal are provided in communication with each of the liquid level detection means and each selection means, and when the liquid level detection means outputs the detection signal, the detection signal is detected. A control means for switching the selection means corresponding to the liquid level detection means that outputs the signal from communication between the moving tank and the suction channel to communication between the moving tank and the dropping channel; This eliminates the need for tank monitoring for each moving tank and frequent valve operations as in the past, resulting in significant labor savings and preventing air from being sucked into the transfer pump, thus preventing cavitation. can. In addition, a plurality of mobile tanks can be arbitrarily connected to each other without connection to other mobile tanks to receive liquid from the mobile tank, and furthermore, each mobile tank has a suction flow path and a drop flow path. It can be automatically switched to quickly accept liquid from a mobile tank.

[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. 2... Dump tank, 3a, 3b... Transfer pump (transfer pump means), 4... Control panel (control means), 5... Tank truck (mobile tank), 6...
...Selection means, 9...Automatic three-way valve, 8a, 9a...
Limit switch (switch means), 10, 11
... Header pipe, 13 ... Level switch (liquid level detection means), A ₁ , A ₂ , B ₁ , B ₂ ... Piping.

Claims (1)

[Claims] 1 A transfer pump means, a dump tank provided at a lower position than the mobile tank, and a plurality of mobile tanks individually connected to each other and switching between a suction flow path to the transfer pump means and a drop flow path to the dump tank. a plurality of selection means; and a plurality of liquid level detection means provided individually corresponding to the plurality of selection means and configured to detect that the liquid in the mobile tank has fallen to a predetermined liquid level and output a detection signal. , are provided in communication with each of the liquid level detection means and each of the selection means, and when the liquid level detection means outputs the detection signal,
control means for switching the selection means corresponding to the liquid level detection means that outputs the detection signal from communication between the moving tank and the suction channel to communication between the moving tank and the dropping channel; A device for receiving liquid from a mobile tank, characterized in that: