JPS648200B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to measuring pumps, and more particularly to static measuring pumps for measuring and transferring quantities of fluid.

BACKGROUND OF THE INVENTION Many conventional devices for measuring and transferring fluid volume are of a positive displacement type. These utilize the displacement of the pump to measure the volume of the fluid. However, positive displacement pumps have their own problems as described below. That is, inaccuracies due to component wear, operating speed fluctuations due to input fluctuations, and leakage from pump seals. In addition, leakage poses problems in measurement accuracy, and when used to measure hazardous fluids, leaked fluid or vapor poses a safety issue. This poses a problem in terms of management. The seals of high-speed measurement pumps are subject to various failures, so it is necessary to stop the operation of the pump each time. In applications where there is a high risk of major damage, such as a shutdown due to a stoppage of the measurement function, it is generally necessary to have a backup pump in case of pump failure.

The discharge volume of a typical positive displacement pump is usually
It is small compared to the amount of fluid to be measured per measurement. Therefore, in order to measure the required amount of fluid, the number of measurements is relatively large and the number of rotations of the pump is also increased. The errors that occur when a normal pump performs one cycle of operation are accumulated during the measurement process, so even if the error per cycle in such a pump is small, it will be This results in a non-negligible overall error in the volume of fluid applied. An additional problem with known pumps is that, as mentioned above, not only do they become less accurate with use, but these pumps must be calibrated periodically.

The output flow of common measuring pumps is pulsating, which is inconvenient for some applications.

In addition, typical measurement pumps are designed for fluids in a narrow viscosity range. Therefore, it cannot be used to measure glycerin or ethyl alcohol, for example.

The object of the invention is to provide a static measuring pump for measuring and dispensing the dispensed liquid without any moving parts, thus solving the problems in the known art.

Another object of the invention is to provide a static metering pump that eliminates the problems caused by rotating seals found in conventional metering pumps.

Another object of the invention is to provide a static measuring pump of very high precision.

Another object of the invention is to provide a static metering pump in which the volume delivered in one cycle of operation is relatively large compared to the total volume dispensed at one time.

Another object of the invention is to provide a static measuring pump that is free from liquid or vapor leakage.

Another object of the invention is to provide a static measuring pump that can be used for sterilizing heating without damage.

Another object of the present invention is to provide a static measuring pump that can provide a pulsation-free output in contrast to the pulsation in the discharge output of general measuring pumps.

Another object of the invention is to provide a static measuring pump that is easily adaptable to operation with liquids of different viscosities.

Yet another object of the invention is to provide a static metering pump having relatively few and simple components that can be manufactured economically.

According to the invention, a static metering pump is provided that includes a pair of tanks connected by a pipe communicating between the tops of the tanks. Each tank is provided with electrically operated input and outlet valves. The two outlet valves lead to the discharge pipe and are connected to an electrically operated three-way valve. The inlet pipe is connected to two inlet valves. It also includes a liquid level detector installed in each tank, a control panel and electrical wiring between the control panels, an inlet valve, an outlet valve, a three-way valve, and a liquid level detector, and further includes an electrically operated liquid level detector. A control device is provided.

During operation of the static measuring pump, the first tank of the two tanks is filled with liquid while discharging liquid from the second tank, and the liquid level in the second tank is below the predetermined liquid level in the first tank. When this happens, the inlet valve, outlet valve, and 3-way valve are automatically reset, and the second tank is filled and the first tank is filled.
Liquid is released. Filling and emptying the tank as described above continues automatically until a predetermined number of cycles have been completed, a predetermined amount of liquid has been measured, and the static metering pump is occluded.

According to the invention, the liquid flow from the static metering pump is created by pressurizing the air or gas above the liquid level in the tank using electrical power alone or an external pressurization source. Additionally, the liquid itself may be pressurized using an external pressure pump.

According to another embodiment of the invention, the outlet pipe is connected to a third tank that includes a pair of adjustable-mounted electrically operated liquid level detectors, whereby the liquid under high pressure is Discharge becomes possible. A high pressure pump and a level detector are electrically connected to an electrically operated pump speed control device. In this embodiment, the pump speed controller increases the speed of the high pressure pump when the liquid level in the third tank rises above the liquid level detector configured as a high liquid level detector. When the liquid level drops below the level detector configured as a low level detector, the pump speed controller reduces the speed of the high pressure pump. As mentioned above, variations in pump speed caused by changes in the input provided for operation of the high pressure pump are compensated for in the pump speed controller. Since the high pressure is generated by the high pressure pump, this embodiment has the advantage of being able to measure the flow rate under high pressure even if the tank of the static measuring pump is made to withstand relatively low pressures.

Additional objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.

FIG. 1 shows a static measuring pump 10 according to the invention. The static metering pump 10 includes a pair of tanks 12 connected by a tube 16 so that air or other gas can flow from one tank to the other.
14 are included. The static measuring pump 10 further includes:
A pair of electrically operated intake valves 18, 20 are included in the intake pipe 22. tank 1
The tubes 24, 26 terminate below the tanks 12, 14 and are configured so that no agitation occurs during filling of the tanks 12, 14. Inlet valves 18, 20 are connected to this pipe 24, 26.

The tanks 12 and 14 have replaceable orifice members 28 and 30, respectively. The orifice members 28, 30 are interchangeable with a pair of different orifice members or with orifice members of similar construction and openings of various sizes, so that the static measuring pump 10 can measure liquids with different viscosities. becomes possible.

From the orifice members 28, 30, pipes 36,
a pair of outlet valves 3 electrically operated via 38;
It continues to 2,34. In addition, the outlet valves 32, 3
4 is connected via pipes 42, 44 to an electrically operated three-way valve 40. The liquid measured by the three-way valve 40 is discharged through the pipe 46.

Each tank 12, 14 includes a known electrically operated liquid level control device. A suitable liquid level control device 48 is a liquid level control device 48.
US Pat. Liquid level control device 4 for each tank 12, 14
8 are identical and each level control device 48 includes a magnetic floating member 50, 52 consisting of a disc-shaped magnet (not shown) molded within a buoyant plastic capsule. Vertical pipes 54, 56 connected to the top and bottom of tanks 12, 14, respectively
Magnetic floating members 50, 5 are placed on the surface of the liquid present in the
2 is located. A pair of reed switches 58, 60 and 62, 6 are provided on the outer periphery of the vertical pipes 54, 56, respectively.
4 is mounted and arranged on a slider (not shown) so that the vertical position of the reed switches 58, 60, 62, 64 can be adjusted.
When one of the magnets attached to either of the floating members 50, 52 passes one of the reed switches 58, 60, 62, 64, the reed switch is operated by the magnet and an electric circuit is closed. Intake valve 18,
A liquid level control device 48 is electrically connected to 20 and outlet valves 32 and 34, and these valves operate to maintain the liquid level in the tank at a desired position in the manner described below. be done.

Reed switches 58, 60, 62, 64 are mounted adjacent to scales 66, 68 that are calibrated in units of volume. A set of divisions may be provided on each scale 66, 68 to accommodate changes in the viscosity of a single fluid due to changes in operating temperature or to fluids of different viscosities. In the description of the liquid level control device according to US Pat. No. 3,703,246, liquid level control device 48 is described for illustrative purposes.
It is also understood that static metering pump 10 may incorporate any one of a number of liquid level control devices that provide or modify electrical signals responsive to changes in liquid level in a tank.

Each tank 12, 14 has a reed switch 58, 62 in its uppermost position to provide an emergency signal when the reed switch 58, 62 is inoperative and to avoid undesirable overfilling of the tank 12, 14. Individual emergency detection switches 70, 72 are provided.

The static measuring pump 10 includes a control panel 74 with the following switching and control devices:

That is, the counter preset and control device 7
6, on/off switch 78, first fill switch 80, start switch 82, first emergency switch 84 and second emergency switch 86. The control panel 74 and the various elements of the static metering pump 10 are connected via a plurality of leads 88, which are discussed individually in the operational description below.

The measurement operation is performed by alternately and continuously emptying tanks 12 and 14 and filling one tank as the other tank empties. The set positions of the upper reed switches 58, 62 and the lower reed switches 60, 64 configure each tank to dispense a precise volume of liquid, for example 10 gallons. Upper reed switches 58 and 62 are connected to tanks 12 and 14, respectively.
The lower reed switches 60 and 64 act as detectors for the empty level of liquid in the tank, which is the terminal level at tank discharge. full level detectors 58, 62 and empty level detector 60,
64 is set according to the volume of liquid to be dispensed, for example 10 gallons. Thus, in each discharge cycle of tanks 12 and 14,
A volume of exactly 10 gallons is dispensed.

The total volume of liquid to be dispensed is set by a counter preset on the control panel and controller 76 to a total volume of, for example, 60 gallons. Static measuring pump 1
0 will then operate to automatically empty tanks 12 and 14 alternately about 6 times until 60 gallons of liquid have been properly measured.

is not a correct multiple of the preset volume dispensed in tanks 12 and 14, e.g. 64
Tank 14 to measure total volume, such as gallons.
A fraction detector 85, shown in FIG. 2 in the form of a magnetic reed switch 87 configured therewith, is provided on the static measuring pump. A reed switch 87 is slidably mounted adjacent a scale 89 calibrated in fractions of the volume dispensed by tank 14. The detector 85 is manually set to the desired fractional value, and when the measuring device is in operation, the tank 14 is partially filled to the position of the fractional detector 85, as described above, and the fractional component is discharged first. be done. Tanks 12 and 14 then alternately discharge their total volume until the desired total volume of liquid has been measured.

The operation of the static measuring pump 10 will be explained with reference to FIG. Before starting the measurement operation, the operator:
The counter presets on control panel 74 and controller 76 set the desired total volume. This total volume is the same for each tank, for example 60 gallons.
It may be a positive multiple of the 10 gallons filled and discharged in 2 and 14. However, if the desired total volume is not a correct multiple, such as 64 gallons, the operator simply sets the fractional quantity at counter preset and control 76 to 4 gallons. In addition, he manually moved the sliding reed switch 87 of the fraction detector 85 to a position indicating 2/5 of the volume of the tank 14, or 4 gallons, on the calibration scale 88.
Match the points above.

The operator then depresses the on/off switch 78 to start the device and then depresses the first fill switch 80 on the control panel to begin one of the alternating fill cycles. If a fractional quantity is not set in counter preset and controller 76 and fractional detector 85, first fill switch 80 sends an electrical signal via lead 90,
The intake valves 18 and 20 are opened and the lead 9
An electrical signal is sent through 2 to adjust the three-way valve 40 to allow flow from tank 12 and prevent flow from tank 14. Liquid also flows from a source (not shown) through tube 22 in the direction shown by arrow 94 in FIG. 2, filling tanks 12 and 14. When the liquid levels in tanks 12 and 14 reach the positions of reed switches 58 and 62,
A signal is sent through leads 96 and 98 to close intake valves 18 and 20. The static measuring pump 10 is now ready for measuring operation, and the tank 1
Tanks 12 and 14 are emptied alternately until the desired total volume is reached. Thus, if a total metered volume of 60 gallons is required, six discharges will be made in two tanks.

On the other hand, if the total volume of liquid to be dispensed has a fraction of the volume of the tank, and this fraction is set in the counter preset and control device 76, the operator presses the first fill switch 80. When intake valves 18 and 20 are opened by a signal via lead 90 and an electrical signal is provided via lead 92, three-way valve 40 is controlled to allow flow from tank 14 and to open the tank. Outflow from 12 is prevented. Liquid thus flows to tanks 12 and 14 via pipe 22 and open intake valves 18 and 20. When the liquid level reaches the reed switch and tank 12 is filled to its full capacity of 10 gallons, detector 58 and intake valve 18 close. However, the reed switch 87 of the fraction detector 85 is installed in the tank 14.
When the liquid level is reached, only a predetermined fractional volume is filled, determined by closing the intake valve 20 via the lead 91.

It will be appreciated that depressing the first fill switch 80 effectively primes the static metering pump so that both tanks 12 and 14 are filled to the desired capacity. If a fractional total volume is set, the fractional volume, such as 4 gallons, will be filled in the tank 14 and discharged at the beginning of the measurement cycle. However, if a fraction is not required, tank 14 is filled to a full volume of 10 gallons and tank 12 is discharged from the beginning of the measurement cycle.

Once the static metering pump 10 has been properly primed, a signal light (not shown) on the control panel will be illuminated to notify the operator that priming is complete. Then, the operator starts the measurement operation.
Press the start switch button 82. If the fractional total volume is not set on control panel 74, the output valve 32 is connected from start switch 82 via lead 100.
An electric signal is sent to the outlet valve 32, and the outlet valve 32 is opened by this signal. Liquid begins to flow from tank 12 through tube 42, three-way valve 40, and tube 46. tank 1
When the liquid level in tank 2 reaches the position of reed switch 60, a signal is sent through reeds 102, 104, 106 and 108, closing outlet valve 32, opening outlet valve 34, and shutting off the flow from tank 14. The position of the three-way valve 40 is switched to allow outflow and prevent outflow from tank 12, and
The intake valve 18 is opened.

Liquid now begins to flow out of tank 14 and tank 12 is refilled. When the liquid level in tank 14 reaches the position of reed switch detector 64, a signal is sent through reeds 110, 112, 104, 106 and 114, and outlet valve 34 is activated.
is closed, the outlet valve 32 is opened, and the tank 1 is closed.
The position of the three-way valve 40 changes to allow outflow from tank 14 and prevent outflow from tank 14, and
The intake valve 20 is opened. Liquid now flows out of the tank 12 and the tank 14 is refilled. This cycle of operation is automatically repeated until the number of cycles preselected on the control panel 74, and when a predetermined volume of liquid has been dispensed, the counter preset and control device 74 controls the static metering pump 1.
Stop the operation of 0.

If a fractional total volume is set on the control panel 74, depressing the start switch 82 sends an electrical signal through the lead 93 to the outlet valve, opening the outlet valve 34. Liquid now flows from tank 14 via tube 44, three-way valve 40 and tube 46. When the liquid level in tank 14 reaches the position of reed switch 64 to dispense a fractional volume of 4 gallons, a signal is sent through leads 110 and 112 to close outlet valve 34 and close outlet valve 32. is opened, and a signal is sent via a lead (not shown) to prevent outflow from the tank 14 and change the position of the three-way valve 40 to allow outflow from the tank 12. 114 to open the intake valve 20. Liquid now flows out of tank 12 and fills tank 14 to its full capacity of 10 gallons. Tanks 12 and 14 are then alternately filled and drained until the total volume required to be measured is reached.

In this way, precisely measured liquid volumes can be dispensed by the static measuring pump 10 by simply setting the desired volume (including any fractional values) to be applied on the counter preset and control device 76. What you are given will be appreciated. The set of devices alternately fills and empties tanks 12 and 14 to automatically measure the desired volume. The effect is tank 1
2 and 14 alternately filling and emptying to automatically measure the desired volume. Efficiency of static measuring pump is always constant and replaceable orifice member 2
By selectively changing 8 and 30, it is unaffected by changes in the liquid flow rate. Accurate measurement of the desired volume, no matter how the flow rate is selected, cannot be achieved with conventional rotary or piston-type measuring pumps based on movement of internal mechanisms.

The application of static measuring pump 10 is illustrated in FIGS. 3-5. Figure 3 shows the storage tank 116 lifted up.
A static metering pump 10 is shown gravity-fed via a tube 118 from a tank 118 and delivering liquid via a tube 120 by the action of gravity to the process in a tank 122 shown in FIG. FIG. 4 shows static metering pump 10, which is fed via line 126 from an internally pressurized storage tank 124 and provides pressurized liquid via line 128 to the process, shown as tank 130. Figure 5 shows the storage tank 13.
2 via pipe 134 and tank 13
6 shows a static metering pump 10 supplying liquid to the high pressure process shown in FIG. A pressure pump 138 is connected in a pipe 140 between the static measuring pump 10 and the tank 136 and pumps liquid to the equipment in the tank 136.

In a second embodiment of the invention, shown in FIGS. 6 and 7, static metering pump 10 is adapted to dispense liquid under high pressures, on the order of several hundred pounds per square inch. . This embodiment is characterized by the use of a high-pressure pump 142 that pressurizes the liquid, but the static measurement pump 10 only needs to withstand relatively low pressure, so it is inexpensive to construct.

Referring to FIG. 6, a tube 46 leading from the three-way valve 40 is connected to an intake 144 of a pressure tank 146. Pressure tank 146 is connected to high pressure pump 142 via tube 148 and is connected to high pressure pump 14
2 delivers liquid under high pressure via tube 150. a pair of liquid level detectors adjustably mounted on the tank 146 and configured similar to magnetic floats of the type shown in FIGS. 1-6 for providing an electrical signal in response to the liquid level within the tank 146; 152 and 154 are included in tank 146.

Pump speed adjustment unit 156 is connected to lead 15
8 and 160 to liquid level detectors 152 and 154, and via lead 162 to high pressure pump 142. If the high pressure pump 142 fails for any reason, such as a routine drop in the external line voltage supplied to the pump's input power line 162, the liquid level in the tank 146 will rise. When the liquid level reaches the level detector 152, a signal is sent via lead 158 to the pump speed controller to increase the speed of the pump 142 and draw liquid from the tank 146 at an increased flow rate. Ru. When the liquid level reaches the position of the liquid level detector 154, a signal is sent via lead 160 to the pump speed controller 156, causing the pump 142
speed decreases. The position of the liquid level detector 154 is adjustable, and the position is selectively set so that the change in outward liquid flow rate in the tube 150 is negligible. This arrangement of the speed control device of the pump 142 allows the speed of the pressurizing pump 142 to increase beyond a specified value due to fluctuations in the input power supply voltage, and the amount exceeding the processing capacity of the static measuring pump 10 to be increased.
42 or pressurized pump 142.
Eliminate problems that cause depletion of resources.

The above-described speed control device prevents temporary under-speeding of the pressure pump 142 and a decrease in the accuracy of the measurement of liquid dispensed from the static metering pump 10, such as is generally caused by a failure of the pressure pump. Compensate for.

While a preferred embodiment of the invention has been shown and described in detail, it will be obvious that numerous reductions, modifications and additions may be made without departing from the spirit and scope of the invention.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of a static pump according to the invention showing a pair of connected pumps and the valves and detectors and control panel configured therein; FIG. 2 shows electrical connections between the various components; Fig. 1 is a general functional diagram of the static pump shown in Fig. 1 showing the signal flow, and Fig. 3 is a general front view of the application example of the static pump shown in Fig. 1 showing the static pump with gravity feeding. 4 is a schematic front view of another application example of the static pump shown in FIG. A schematic front view of yet another application of the static pump shown in Figure 1 with the addition of a pressure pump, and Figure 6 with an additional tank and high pressure pump for delivering fluid under very high pressure. FIG. 7 is a general functional diagram of the second embodiment of the static pump shown in FIG. 6; , 14 is a tank, 18, 20 is an intake valve, 28, 30 is an orifice member, 32, 3
4 is an outlet valve, 40 is a three-way valve, 50 and 52 are floating members, 74 is a control panel, 85 is a detector, 86 is an emergency switch, and 88 is a calibration scale.

Claims (1)

[Scope of Claims] 1. A static measuring pump for measuring the volume of a liquid, comprising: a pair of tanks; and pipe means connected to the upper part of the tanks for equalizing the pressure in the tanks;
a pair of electrically operated intake valves, each disposed at the upper part of the tank; a pair of electrically operated outlet valves, each disposed at the lower part of the tank; separate outlet pipes communicating with a common discharge pipe and preselected within said tank;
upper and lower liquid level detectors for detecting a set fill level and an empty level; between said level detectors there is a normally preset liquid cavity of equal volume in each of said tanks; formed, said cavity sized to contain a conventional predetermined volume of liquid, and having circuit connection means interconnecting said inlet valve, said outlet valve and said upper and lower liquid level detectors; , said inlet and outlet valves so as to discharge liquid from one of said tanks while filling the other tank from an external liquid source, and to discharge liquid from said other tank while filling one of said tanks. the upper and lower liquid level detectors and the circuit connection means are adapted to open and close the
After the static metering pump has ceased operation, a predetermined number of tank fill and drain cycles are performed until a selected total volume of liquid representing a multiple of the preset normal volume has been dispensed from the two tanks. electrically operated control means for automatically achieving and dispensing a predetermined volume of liquid; and an adjustable fractional level detector for detecting a fractional fill level for one of said tanks during a measuring operation. Static measuring pump, characterized in that it is arranged in one of said tanks intermediate the upper and lower level detectors, said control means being adapted to start a measuring cycle at the discharge of one of said tanks. . 2. an adjustable liquid level detector mounted for selected vertical movement relative to one of the tanks and configured with a scale calibrated in fractions of the total volume of one of said tanks; Static measuring pump according to claim 1, characterized in that is set to a selected fraction of the capacity of the tank. 3. Static measuring pump according to claim 1, characterized in that the liquid level detector consists of a high level detector and a low level detector mounted on each tank. 4. A magnetic float configured with each of the tanks so that each float follows the liquid level in each tank, and a pair of reed switches mounted close to each of the tanks, one reed switch is fitted for registering a selected fill level of each of said tanks and the other reed switch is fitted for registering a selected empty level of each of said tanks. A static measuring pump according to claim 1. 5. A reed switch is mounted for adjustable vertical movement relative to each tank so that selected fill and empty levels of said respective tank can be selectively varied. Static measuring pumps as described in section. 6. Each tank has an outer vertical pipe configured to communicate with the upper and lower parts of the respective tank, so that the liquid in the vertical pipe is at the same level as the liquid level in the respective tank, and 5. The static measuring pump of claim 4, wherein a magnetic float is contained within the vertical tube and remains above the liquid level within the vertical tube, and a reed switch is provided adjacent to the vertical tube. . 7 To guide the gas that pressurizes the liquid level in the tank,
Static measuring pump according to claim 1, characterized in that it includes a gas inlet mounted at the top of one of the tanks. 8 a third tank communicating with the outlet pipe; and a third tank communicating with the outlet pipe;
a high liquid level detector and a low liquid level detector provided in the tank; an outlet pipe communicating with the third tank; a pressure pump attached to the outlet pipe; and the pressure pump and the high liquid level detector. and a pump speed control means connected to the low level detector, in response to a liquid level rising in the third tank above the high liquid level detector, the pressurizing pump and the pump speed control means is adapted to increase the speed of the pressurizing pump and decrease the speed of the pressurizing pump in response to a liquid level falling below the low level detector in the third tank. Claim 1 characterized by
Static measuring pumps as described in section. 9. Static metering pump according to claim 1, characterized in that each of the tanks communicates with an outlet valve and has a replaceable outlet orifice. 10 an emergency detection switch disposed on a high level detector is provided with each of the tanks, said emergency detection switch being adapted to provide an emergency alert signal in the event of said high level detector being inoperative; 4. The static measuring pump according to claim 3, wherein overflow from the tank is suppressed.