JPS6025633B2 - Pressure tank air replenishment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic air replenishment device for a pressure tank that automatically replenishes air to the pressure tank of a liquid supply device that combines a liquid supply pump and a pressure tank.

In a liquid supply device that combines a liquid pump and a pressure tank, the air in the pressure tank gradually decreases.

As a result, the amount of air becomes insufficient and the number of times the liquid supply pump starts and stops increases. Therefore, when the amount of air becomes insufficient, air must be replenished into the pressure tank. For this reason, conventionally, an air supply tank equipped with an air suction valve and a first automatic opening/closing valve for drainage is installed on the side of the pressure tank, and the lower part of the air supply tank and the lower part of the pressure tank are connected to the second automatic valve.
The top of the air supply tank and the pressure tank were connected to each other through a check valve. Each time the pump stops, the first automatic opening/closing valve is opened to suck air into the air supply tank, and each time the pump is started, the second automatic opening/closing valve is opened to collect the pressurized liquid sent from the pump. A portion of the air is introduced into the air replenishment tank, and the internal air is compressed and pressurized into the pressure tank, thereby automatically replenishing air into the pressure tank. However, according to this method, air is automatically replenished almost regularly, regardless of the amount of air in the pressure tank.
The amount of air increases more than necessary, and the lowest liquid level in the pressure tank falls below the planned liquid level. In a liquid supply device using a pressure tank, if the liquid level in the pressure tank drops too much, air may be mixed into the liquid to be delivered. In order to prevent such a phenomenon, some measure must be taken to prevent the liquid level in the pressure tank from falling below the allowable minimum liquid level. Therefore, in the past, an electrode bar for detecting the liquid level was installed in the pressure tank to limit air supply so that the liquid level did not fall below the allowable minimum liquid level. There is also a pressure tank in which an exhaust valve is attached to the lowest allowable liquid level part of the pressure tank, and the excess air inside is discharged by this exhaust valve. However, the device in which the liquid level in the pressure tank is controlled using an electrode rod has the disadvantage that the structure is complicated and the control device is expensive. In addition, a device designed to exhaust excess air in the pressure tank requires an exhaust valve, which is not only expensive, but also makes it difficult to exhaust the air that has entered the pressure tank. As a result, there is a large loss, and there are also disadvantages such as the generation of exhaust noise during exhaust. The present invention has been made in view of the above points, and has a simple structure that eliminates expensive parts such as electrode guides or exhaust valves, and is more reliable and efficient. An object of the present invention is to obtain an air automatic replenishment device for a pressure tank that can always maintain and adjust the lowest liquid level of a pressure tank at a predetermined liquid level. In order to achieve the above object, the present invention is characterized in that a liquid supply device that combines a liquid supply pump and a pressure tank has an air intake valve and a first drain valve on the side of the pressure tank. An air supply tank equipped with an automatic opening/closing valve is installed, and a second automatic opening/closing valve is installed to connect the lower part of the air supply tank and the piping below or in the vicinity of the pressure tank, and the air supply tank is connected to the second automatic opening/closing valve. A check valve is passed between the top of the pressure tank and the pressure tank, and air is supplied into the pressure tank by automatically controlling the first and second automatic opening/closing valves to open and close alternately in a predetermined order. In things,
The atmospheric screaming pressure is Po, the pressure in the pressure tank that stops the liquid supply from the liquid supply pump is P2, the total volume of the air supply tank is vo, and the volume of the portion located above the liquid level is v2. In this case, when the pressure in the pressure tank reaches P2 and is at the desired liquid level with the first automatic on-off valve closed and the second automatic on-off valve opened, the volume of the air supply tank v2 The target value of v2=(p./p2)÷.
v. (r: specific heat ratio). An embodiment of the present invention shown in the drawings will be described below.

Reference numeral 1 denotes a pressure tank, and below the pressure tank, a pipe 2 leading from a liquid supply pump P to the general liquid system and a lotus pipe 3 are connected in the vicinity of the liquid supply pump P.

4 is a pressure switch attached to the pressure tank 1, which detects the pressure inside the pressure tank, and if the pressure inside the pressure tank 1 is pressure P, starts the liquid supply pump P to supply liquid. If the pressure in the pressure tank 1 is P2, a start/stop signal is applied to the drive device of the liquid supply pump P to stop the liquid supply pump P and stop the liquid supply. be.

LWL is a predetermined minimum liquid level, and is set to a level at which air is not mixed into the liquid in the pipe 2 leading to the liquid supply system. When the liquid level in the pressure tank 1 is LWL and the internal pressure is P, start the liquid supply pump P to start liquid supply, and the liquid level when the pressure in the pressure tank 1 reaches the pressure P2. is the liquid level HW
It is L. By predetermining the lowest liquid level LWL, this liquid level HWL can be determined in advance from Poisson's equation, that is, PVr=constant (r: specific heat ratio) {1}.

That is, if the pressure in pressure tank 1 is pressure P, and the liquid level is liquid level LWL, and the volume of air in pressure tank 1 is V, then the pressure in pressure tank 1 has reached pressure P2. The volume of air V2 at the time is P.・V, r; P2・V2
From r'21, . V
2=(P,/P2)71V, {3} The desired value of the liquid level HWL can be determined from this volume V2.

Reference numeral 5 denotes an air replenishment tank, and if the total volume of the air replenishment tank 5 is vo and the atmospheric pressure is Po, then the liquid level of the air replenishment tank 5 is lower than the liquid level of the air replenishment tank 5 when the pressure tank 1 and the air supply tank 5 are in communication. The upper volume v2 is V2=(p.

/p2)÷. V. '41, it is installed on the side of the pressure tank 1. This air supply tank 5 has a first automatic opening/closing valve 6 interposed therein, and has a pseudo liquid pipe 7 at one end which communicates with the lower part of the air supply tank 5 and which is open to the atmosphere at the other end, and an intake valve 8 at one end. The air supply tank 5 is provided with an intake pipe 9 which passes through the upper part and the other end is open to the atmosphere. Reference numeral 11 designates a liquid guide pipe enclosing the second automatic on-off valve 10, one end of which is conveyed to the lower part of the air supply tank 5.
The other end is routed to the bottom of the pressure tank.

Note that, as long as the other end of the liquid guiding pipe 11 is located near the lower part of the pressure tank 1, the other end may be connected to the piping 2, which connects the liquid supply pump P and the pressure tank 1, or to the transport pipe 3, for example. Reference numeral 13 denotes an air supply pipe with a check valve 12 interposed therebetween, one end of which communicates with the top of the air supply tank 5, and the other end of which communicates with the pressure tank.

The first and second automatic on-off valves 6 and 10 are opened and closed by, for example, starting and stopping the liquid supply pump P. That is, when the liquid supply pump P is started, the first automatic on-off valve 6 is closed, the second automatic on-off valve 10 is opened, and the first automatic on-off valve 6 is opened in conjunction with the stop of the liquid supply pump P. Open, second automatic on-off valve 10
Close it. In addition, each automatic opening/closing valve 6,
The closing operation of No. 10 is not linked to the start and stop of the liquid supply pump P, but after the opening operation is performed in conjunction with the start and stop of the liquid supply pump P, the closing operation is performed after a certain period of time by the action of the timer means. Good too. Further, the automatic opening/closing valves 6 and 10 may be opened and closed alternately at predetermined time intervals without being linked to the starting and stopping of the liquid supply pump P. The operation will be explained below.

When explaining the operation, for convenience, the first and second
The automatic opening/closing valves 6 and 10 are opened and closed by starting the liquid supply pump P,
It is assumed that it is linked to the stop. That is, the first automatic on-off valve 6 is closed and the second automatic on-off valve 10 is opened in response to the start-up of the liquid supply pump P. It is assumed that in conjunction with the stop of the liquid supply pump P, the first automatic on-off valve 6 opens and the second automatic on-off valve 10 closes. Now, the liquid supply pump P is stopped, and the liquid level reaches the liquid level LWL because the air in the pressure tank 1 is at a specified level, and at the same time, the pressure in the pressure tank 1 increases to the pressure P.
．． Suppose that it has reached . By this point, the air supply tank 5 is filled with air. That is, the liquid supply pump P
When the engine stops, the first automatic on-off valve 6 opens and the second automatic on-off valve 10 closes. When the first automatic on-off valve 6 opens, the liquid in the air supply tank 5 is discharged through the gE liquid pipe 7. As a result, the inside of the air supply tank 5 becomes negative pressure, and air is fed into the air supply tank 5 through the intake valve 8 and the intake pipe 9. In this way, air is supplied into the air supply tank 5 while the liquid supply pump P is stopped. When the pressure inside the pressure tank 1 reaches pressure P, the pressure switch 4 detects this and starts the liquid supply pump P. At the same time, the first automatic on-off valve 6 is closed and the second automatic on-off valve 10 is opened. By starting the liquid supply pump P, pressure liquid is introduced into the pressure tank P, and at the same time, a part of the pressure liquid is introduced into the air supply tank 5. As a result, the liquid level in each tank 1, 5 rises. When the liquid supply pump P is started, the pressure in the pressure tank 1 is P, and the liquid level is LWL. Therefore, from the above formula The liquid level when the switch 4 detects this and stops the liquid supply pump P becomes the liquid level HWL. Since the second automatic on-off valve 10 is open, the pressure tank 1 and the air replenishment tank 5 are at the same level, so the liquid levels in these tanks 1 and 5 are almost the same. That is, when the liquid supply pump P is stopped, the liquid level in the air supply tank 5 becomes almost the same as the liquid &HWL. By introducing the pressure liquid, the air in the air supply tank 5 is compressed from a state equal to atmospheric pressure Po. However, the volume v2 located above the liquid level HWL of the air supply tank 5
is shown by the formula {4}, so that by the time the liquid level in the pressure tank 1 reaches the desired liquid level HWL, the pressure reaches pressure P2, and the liquid supply pump P stops, the amount in the air supply tank 5 increases. According to the above formula [4', the pressure increases only up to pressure P2. That is, the pressure in the pressure tank 1 will not rise above the pressure, and therefore the air in the air supply tank 5 will not be pressurized into the pressure tank 1. Next, if the air in the pressure tank 1 decreases for some reason, or the amount of air in the pressure tank is small as when installing the pressure tank,
When the pressure inside the pressure tank drops to pressure P2, the liquid level becomes higher than the liquid level LWL.

The pressure switch 4 detects the pressure P2 in the pressure tank 1 and starts the liquid supply pump P. At the same time, the first automatic on-off valve 6 closes and the second automatic on-off valve 10 opens. By starting the total liquid pump P, the pressure tank 1 introduces the pressure liquid from the liquid supply pump P, and also transfers a part of the pressure liquid to the air supply tank 5.
to be introduced within. Since the amount of air in the pressure tank is insufficient, the pressure in the pressure tank 1 reaches pressure P2, and when the pressure switch 4 stops the liquid supply pump P, the liquid level will be lower than the desired liquid level HWL. Therefore, at this time, the volume of the air supply tank 5 located above the liquid & is also 4. Since the volume mentioned above is smaller than 2, the pressure in the pressure tank 1 will change from pressure P to pressure As we approach P2,
A portion of the air in the air supply tank 5 is pressurized into the pressure tank 1 so that the pressure in the pressure tank 1 and the pressure in the air supply tank 5 are the same. That is, air is replenished into the tank 1. Thereafter, as long as the amount of air in the pressure tank 1 is insufficient, air is replenished every time the liquid supply pump P is started. Then, the amount of air in the pressure tank 1 reaches the specified amount, and the pressure in the pressure tank 1 becomes the pressure P,
The liquid level is liquid level LWL, and the pressure in pressure tank 1 is pressure F2.
When the liquid & satisfies the desired liquid & HWL conditions, the pressure in the air replenishment tank 5 will remain at pressure P2 even if the air replenishment operation is repeated, as long as there is no shortage of air in the pressure tank 1.
Air replenishment is not performed because the above condition does not occur. In this way, air is pressurized into the pressure tank 1 from the air supply tank 5 when the pressure inside the pressure tank 1 is pressure P2 and the liquid level exceeds the desired liquid level HWL. be.

That is, the liquid & at pressure P2 never falls below the desired liquid level HWL. Therefore, '2) and '3 above
From the equation, the liquid & at pressure P, never falls below the liquid level LWL. That is, with a simple configuration that defines the mounting position of the air replenishment tank 5 with respect to the pressure tank 1, the lowest liquid in the pressure tank can always be maintained and adjusted at the planned liquid level LWL. As is clear from the above description, the present invention has a simple configuration in which the mounting position of the air replenishment tank with respect to the pressure tank is defined, and the lowest liquid level in the pressure tank can always be maintained and adjusted at a predetermined liquid level.

Therefore, if this planned liquid & is selected to be above the allowable minimum liquid level at which a large amount of air in the pressure tank will be present during liquid supply and no air will be sent to the outlet side of the pressure tank, air will not be mixed in during liquid supply. can be prevented. Moreover, according to the present invention,
Since expensive parts such as electrodes or exhaust valves that were used in the pressure tank can be omitted, the device can be constructed at a low cost. Also, since excess air is not pressurized into the pressure tank, the air in the pressure tank can be discharged easily. There is no loss, efficiency can be improved accordingly, and there is no noise caused by air exhaust, all of the drawbacks of the conventional technology can be eliminated.

[Brief explanation of the drawing]

The figure is a system diagram showing one embodiment of the present invention.

Claims (1)

[Scope of Claims] 1. An air supply tank that is equipped with an intake valve and a first automatic opening/closing valve for draining liquid on the side of the pressure tank of a liquid supply device that combines a liquid supply pump and a pressure tank. the lower part of the air supply tank and the pressure tank are communicated via a second automatic on-off valve, the top of the air supply tank and the pressure tank are communicated via a check valve, and the Air is supplied to the pressure tank by automatically controlling the first and second automatic opening/closing valves to open and close alternately in a scheduled order, wherein the atmospheric pressure is set to P_0, and the liquid supplied from the liquid supply pump is set to P_0. When the pressure in the pressure tank to be stopped is P_2, the total volume of the air replenishment tank is v_0, and the volume of the portion located above the liquid level in the air replenishment tank is v_2, the first automatic opening/closing valve When the pressure in the pressure tank reaches P_2 and is at the desired liquid level with the second automatic on-off valve open, the target value of the volume v_2 of the air replenishment tank is determined by ▲mathematical formula, chemical formula, There are tables, etc. ▼ (r: specific heat ratio) An automatic air replenishment device for pressure tanks characterized by the following.