JPS6014120A - Flowmeter and flow-rate measuring device with attachment device through which accuracy on measurement is improved - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a flow measuring device having a flow meter, such as an impeller flow meter, and an accessory device for increasing the measurement accuracy in the lower measuring range.

Conventional techniques Flowmeters such as impeller flowmeters, including non-contact monitoring, give very accurate results over very large portions of the measurement range, but are susceptible to measurement errors at small flow rates per unit time. It is well known that one must accept the offer. At very low flow velocities, the flow meter no longer responds with effort. This can lead to various difficulties if a consumption calculation is required on the basis of flow measurements, for example if the consumption of heating water or the amount of heat dependent thereon has to be considered in a remote heating system.

Therefore, a number of additional devices have already become known in order to increase the measurement accuracy of the lower measurement range. In other words, the generation of vibration can reduce the bearing friction of the o-tor of the flow measuring device (West German Patent Application Publication No. 312,468).
3 specification).

By forming a measuring chamber, excessive rises in the error curve can be reduced (German Patent No. 8466', specification no. 24).

By moving the impeller with a jet, it is possible to give the impeller a high rotational speed (West German Patent No. 1 Publication No. 26)
Specification No. 16323''). However, in any case, although it is possible to reduce the measurement error in the lower measurement range, it is not possible to eliminate the fact that the rotor of the flowmeter does not respond thermally at extremely low flow velocities.

Furthermore, flow meters have become known which are intended to measure pulsating flow rates, such as those delivered by fuel diaphragm pumps in motor vehicles. The inlet of the flow meter communicates with a reservoir chamber having a variable volume and defined by a movable wall in the form of a spring-loaded membrane. The opposing membrane surface defines a pressure chamber that communicates with the outlet of the flow meter. The pulsation is flattened by the storage chamber,
A flow meter measures the average flow rate.

Problem to be Solved by the Invention The object of the invention is to provide a flow rate measuring device of the type mentioned at the outset, which not only reduces errors in the lower measurement range but also makes it possible to detect extremely small flow rates. .

MEANS FOR SOLVING THE PROBLEMS The object according to the invention is achieved by: a) a reservoir chamber 9, known per se, with a variable volume defined by movable walls 11, 111; 211; 209, in which the side of the movable wall not facing the reservoir is in communication with the side of the flow cutter not facing the reservoir 29 ; 129 ; 2
b) connected next to the reservoir and in line with the flow rate word 1, which opens when the movable wall reaches a first position (B) corresponding to a larger reservoir volume during outward movement; And it is solved by having a non-return valve 10; 110; 210 which closes when a second position (A) corresponding to a smaller reservoir volume is reached during the inward movement.

In such an arrangement, the check valve is closed when a very low flow rate is occurring. Liquid is thus stored in the reservoir until the movable wall reaches the first position (B). Next, the check valve is opened A', and the constant volume of storage is guided to the flow rate side at once.

As soon as the movable wall reaches the second position, the check valve closes again. In such an operation, flow measurement is not a problem, since the liquid flows through the measuring chamber of the flow meter with a sufficiently high velocity. The check valve may be placed before or after the flow meter.

In the case of a preferred embodiment, a throttle device 22; 122;
0; 110; 210 and are variable from a larger value of aperture resistance to a value of a smaller aperture resistance when the movable wall is moved beyond the first position (B). The throttling device has the effect of extending the delivery of the needle reservoir volume for a certain period of time after opening the check valve, so that the start and end conditions in the flow meter can be ignored. As soon as it becomes necessary to measure a relatively large flow rate, the throttle device 22;
122; 222 automatically becomes inactive, so normal measurements are not disturbed.

It is advantageous if the check valve has a continuous closing movement.

Since the closing movement requires a certain amount of time, the difficulties that arise due to the wake of the flow wave in the case of a jumping closing movement can be avoided. A continuous closing movement can be achieved, for example, by means of a braking device.

The check valve may also be designed as a gradually closing shutter, such as in a camera.

A throttling device is preferably present between the reservoir and the check valve. - In this way the diaphragm device is operated from the movable wall and no sealing member is required.

Advantageously, the movable wall is loaded with an inwardly directed force. This force can be created by springs, elastic materials, weight, corpus cavernosum, etc. This force allows the reservoir fixed volume to be delivered to the flow meter at a predetermined rate after opening of the check valve.

Particularly advantageously, the side of the movable wall facing away from the reservoir defines a pressure chamber that communicates with the side of the flowmeter facing away from the reservoir. In this way, only a certain force has to act on the pressure drop across the flow meter after opening the check valve (so that only a small force is required).

In particular, the i'' moving wall is the roll membrane 13. ．． It has 113.

Since the mesentery has a relatively large stroke, the volume of the reservoir is correspondingly large and the movable wall is separated from the first position and the second position.
The spacing between the positions can be relatively large. However, also suitable movable walls are pistons guided sealingly in cylinders, metal bellows, fixed membranes, etc.

The reverse valve may in particular be a solenoid valve. In this case, an activator is connected to the movable wall, which acts on fixed sensors corresponding to the first and second positions. For example, the actuator is a magnet, and the fixed sensor is a reed switch (Reed-5chal-tcr).

A purely mechanical embodiment is such that the closing member 131 of the non-return valve 110 can be held in the closed and open position by a locking device 140 and a dead-stroke coupler (T
It is connected to the movable wall 111 via an adjustment member 134 via an adjustment member 135, which can be adjusted by means of an adjustment member 135, which can be returned from a closed position to an open position at the end of a dead stroke in each case. At a certain point. The coupling between the locking device and the coupler with a dead stroke is such that the check valve is kept open during each movement of the movable wall from the first position to the second position; Allow the check valve to remain closed between movements.

To form a locking device, recesses 143, 14 are provided in which a locking body 141, which is spring-supported on an adjusting member 135, hangs.
4 may be provided.

Only when the adjustment body is moved with a sufficiently large force will the locking body 141 be pushed out of the recess against the diuretic spring force. In this case coupler 13 with dead stroke
4 has a driver 136,137 connected to the movable wall,
The entrainer has two support surfaces 139° 139 on the adjusting part 135 acting in opposite directions under the intermediate connection of the spring 138.
It can act on aK. Such a dead stroke coupler is quiet and operates safely.

In a preferred embodiment, an adjustable diaphragm section 23 . of the diaphragm device 22 , 122 is provided. '123 has a predetermined rest position corresponding to the value of the throttle resistance, and the entraining body 27,
127 to the movable wall 11, 111, so that when the movable wall exceeds the first position, the diaphragm blade is carried by the entrainment body to an operating position corresponding to a smaller value of the resistance of the diaphragm 9. This is taken into consideration. In this case, all the connecting members are located within the storage chamber and no seal is required.

The driver can also be formed directly on the movable wall or on the adjustment member 35.

The constriction AJ' 23, 123 is very advantageously a filling body which partially fills the outlet 24.degree. 124 of the reservoir chamber 9, 109 in the rest position and which has been moved out of the outlet in the operating position. This results in a small pressure drop at high flow rates.

In other embodiments, the valve seat 132 of the check valve 110
is provided at the outlet 124 of the storage chamber l○9, and a closing member 131 is formed as a valve head, and the throttle member 12
3 may be formed as a filling body connected to the valve head.

The throttling device and the check valve thus form a building block.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will now be explained in more detail by means of preferred embodiments which are illustrated in the drawings.

The flow measuring device 1 shown in FIG. 1 has an inlet pipe 2 and an outlet pipe 3. The flow measuring device 1 shown in FIG. In between there is a flow side 4 arranged in the measuring chamber 5 and designed as an impeller. Optical sensor 6
A contactless scan by the counter 7 sends a signal to the counter 7, the state of which corresponds to the flow rate flowing through at this moment.

In front of the cow, there is a reservoir chamber 9 and a subsequent electromagnetic reverse 11-
An accessory device δ with a valve 10 is connected. The storage chamber 9 has a movable wall 11 formed of L on the fixed plate 2 and the roll film 13. Via the rod 14, sensors 6 and 17 arranged above and below, such as a reed switch (
An actuating body 15, for example a permanent magnet, capable of acting on the Reed-8chalter is connected to the fixed plate.

These sensors are connected via conductors 18 and 19 to a switching device 20, which is capable of energizing the electromagnet of the electromagnetic reverse valve 10. The check valve is provided with a hydraulic brake port 21a, known per se, which retards the closing movement.
・Ru.

The throttle device 22 serves as a throttle member 23 at the outlet 2 of the storage chamber 9.
It has a filling body arranged in 4. In the filling body,
The movable wall 11 is guided by bearings 26 and in the upper part 9:,i
The head 25 is entrainable by an entrainer 27 connected to the
A rod 25 is provided with a.

Three positions of the movable wall are illustrated by letters A, B and CM. At position A, the sensor 16 is excited, at position B, the sensor 17 is excited, and at position C, the entrainer 27 is excited by the head 25a.
It acts on

The movable wall 11 is loaded by a spring 28. On the side facing the storage chamber 9 there is a pressure chamber 29 which is connected via a conduit 30 to the outlet pipe δ.

The flow measuring device operates as follows: in the resting state, the check valve 10 is closed. A very small amount of liquid enters the inlet pipe 2.
The check valve 10 remains closed even if the fluid flows in normally.

However, because the movable wall 11 is moved in three directions 'against the force of the spring 28', the reservoir chamber 9 is expanded. As soon as the movable wall reaches position B and the sensor 17 responds, the non-return valve opens and the accumulated liquid volume flows into the reservoir chamber 9 under the action of the spring 28.
It is pushed out from the flow meter 4 to the outflow pipe 3. At this time, the flow meter 4 is operated satisfactorily by the throttle device 22,
On the other hand, the L restriction is realized such that the flow velocity is sufficient to produce a long measurement time such that the starting and ending conditions do not significantly influence the measurement results. When the movable wall 11 returns to the A position again and the sensor 16 responds, the check valve 10 gradually closes and closes so that the end movement of the impeller flowmeter 4 is not disturbed. This cycle can be repeated over and over again.

On the other hand, if a larger flow rate occurs Q''1, the movable wall 11 is lifted beyond the B position to the C position and above. In this case, the driver 27 acts, so that the throttle member 23 is pulled outward from the outlet 24 and the throttle effect disappears. At such flow rates, the flow meter 4 operates normally and without any notable defects.

The amount of liquid to be stored depends on the various conditions and the type of flow section 7N. In the case of an impeller type flowmeter, it is sufficient to store approximately 4 times the maximum flow rate per unit time. Therefore, in one embodiment, the flowmeter is 40 to 1
During operation in a constant range of 11111 000 t/h, the volume change in the reservoir 9 was a total of 0.2 A.

In the embodiment according to FIG. 2, the control of the check valve 110 is not electromagnetic but mechanical. Reference numerals increased by 100 compared to FIG. 1 are used for corresponding parts. The month before the check valve 110 closes 131, the outlet 1
It cooperates with the valve seat 132 surrounding the two cows. This closing part is integrally connected with a choke part 23 disposed within the outlet 124.

In the case of the movable wall 111, the fixed plate 12 is replaced by a molded part 112 with an annular chamber accommodating the spring 128. The molding part 112 is a coupler 134 with one differential stroke.
It has a rod 133 connected to an adjustment part 135 via. The stroke coupling has two pins J36 and 137 on the rod 133, which are formed as drivers and can act on each one end of the spring 138, and which are opposite to each other and which are It has bearing surfaces 139 and 139a that can cooperate with the other respective ends. The locking device 140 includes two roll-shaped ronokusede-1.
41° C., their shafts are each loaded by a compression spring 142 and can selectively engage a recess 143 of the adjusting member 135 or a recess 144 located below it.

The following operation takes place in this flow measuring device: In the resting state, the non-return valve 110 is closed. At low flow rates, the check valve remains closed. However, the movable wall 111 is moved upward. At this time, the top 3 of the adjustment member
5 is held in the closed position by a locking device 140.

Only when the driver 137 reaches the spring 138 in position B, the adjusting element 135 is carried upwards 11 and at the same time the lock 141 moves from the recess 143 to the recess 144. At this time, the hem l' 125a of the rod 125 is slightly lifted by the driving body 127 of the adjusting part phase 135, and as a result, the check valve 110 is opened, but the throttle device 1
22 still maintains a state of large throttling resistance. The liquid thus stored is supplied by the spring 12 from the outlet to the flow meter. As soon as driver 136 returns to position A, acting on spring 138 from above, adjusting element 135 is moved downwards and check valve 110 is closed again. This cycle can be repeated over and over again.

As the inflow rate increases further, the movable wall 111 is moved further upwards past the B position, and at the same time the rod P 125 and thus the throttling device 123 are pulled upwards, and finally the device is completely pulled out from the outlet 124 at the C position. be raised to. The inflow now enters the flow meter without restriction.

In FIG. 3, reference numerals incremented by 200 are used for corresponding parts, and the reservoir 209 is connected to the inflow pipe 202 via a branch pipe 230, while the outflow pipe 203
is coming out from the pressure chamber 229. The check valve 210 and the restrictor 222 are interconnected as in FIG. The parts of the non-return valve 210 arranged between the closing member and the movable wall 211, such as the dead-stroke coupling, are designed in the same way as in FIG. The movable wall can also be formed by a sealing piston or a metal bellows.

The flow measuring device is particularly suitable for remote heating installations in which it is required to accurately measure water consumption or thermal energy consumption over long periods of time.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a first embodiment of a flow rate measuring device according to the present invention, FIG. 2 is a schematic cross-sectional view of an accessory device of the second embodiment, and FIG. 3 is a diagram of a third embodiment. FIG. In the figure, 1.201...flow measuring device, cow...-flow meter, 8.
108... Attached device, 9,109. '209・Storage room,
10,110,210... check valve, 11, ill,
211・Movable wall, 13, 113... Roll membrane, 15-
... Starting body, 16.17... Sensor, 22.122.
222...Aperture device, 23,123...Aperture previous month, 2
4,124...exit, 27,127-entraining body, 29.
129.229...Pressure chamber, 131...Closing member, 1
32・Valve seat, 134, 234...Coupler with dead stroke, 135...Adjustment member, 136,137・
- Drive body, 138... Spring, 139, 139a - Support surface, 140-0 locking device, 141... Locking point,
143, 144... hollow

Claims (1)

[Scope of Claims] 1. A flow rate measuring device having a measuring device that increases the flow rate and measurement accuracy in a lower predetermined range, the measuring device i: (
8, l O8) is a) a storage chamber (9; 109; 2) known per se with a variable volume defined by a movable wall (11;
09), in this case b] the side of the moving wall not facing the storage chamber defines a pressure chamber (29; 129; 229) connected to the side of the flowmeter (4) not facing the storage chamber; c, and 1]) connected next to the reservoir and in line with the flow meter, which opens when the movable wall reaches a first position (B) corresponding to a larger reservoir volume during outward movement; A second position (A) corresponding to a smaller storage volume when the movable wall moves inward.
The flow rate measuring device is characterized in that it has a check valve (10; 110; 210) that closes when the flow rate is reached. 2. A throttle device (22; 122;
222) is connected to the flow rate side (4) and the check valve (10; 110).
; 210) and a movable wall (11; I
21. The device as claimed in claim 1, wherein the device is capable of changing from a larger value of the diaphragm resistance to a smaller value of the diaphragm resistance when the diaphragm resistance is further moved beyond the first position (B). 3. Device according to claim 1 or 2, in which the non-return valve (10) has a continuous closing movement. Tun Squeezing device (22; 122) is located in storage chamber (9; 109)
4. The device according to claim 2 or 3, wherein the device is located between the non-return valve (4) and the non-return valve (4). 5. Claims 1 to 4, in which the movable wall (11; 111; 211) is loaded inwardly by a force.
Any of the items up to item 1 is the device described in item 1. 6 The movable wall (11; Il construction; 211) is connected to the roll membrane (13
; 113). Apparatus according to any one of claims 1 to 5. 7 The check valve (10) is a solenoid valve and the movable wall (11
), the fixed sensors (16, 17) corresponding to the first and second positions (B, A) are operated on the fixed sensors (16, 17). Device according to scope 7. 9. The closing member (131) of the non-return valve (110) is retainable in the closed and open positions by a locking device (140), and the coupling (134) with dead stroke The adjustment member (13) is connected to the movable wall (111) via the
5), and the adjusting member can be returned from the closed position to the open position at the end of each dead stroke by means of a single-stroke coupling. The device described in any one of paragraphs up to paragraph 6. l○, in order to form a locking device (140), a locking body (141) supported by a spring on an adjusting member (135);
10. Device according to claim 9, characterized in that it is provided with recesses (143, 144) with overhangs (143, 144). 11. The coupling with dead stroke (134) has a driver (136, 137) connected to the movable wall (111), with an adjustment acting in the opposite direction under the intermediate connection of the driver or the spring (138). The two support surfaces on the member (135) (
139, 139a) according to claim 9 or 10. 12. The adjustable diaphragm member (23; 123) of the diaphragm device (22; 122) has a predetermined rest position corresponding to a greater value of the diaphragm resistance;
) is connected to the movable wall (11; 111),
Any one of claims 2 to 11, wherein when the movable wall exceeds the first position fit (B), the throttle member is carried by the driving body to an operating position corresponding to a smaller value of the throttle resistance. The equipment described in section. 13. Device according to one of claims 9 to 12, characterized in that the driver (127) is formed on the adjustment element (135). 14. The throttle part (23; 123) partially fills the outlet (24; 124) of the reservoir chamber (9; 109) in the rest position and is moved out of the outlet in the operating position. The device according to claim 12 or 13, wherein: 15 The valve seat (132) of the check valve (110) is in the storage chamber (
109), and the closing part U (131) is formed as a valve head, and the throttle part (131) is formed as a valve head.
15. Device according to claim 9 or 14, characterized in that 123) is formed as a filling body connected to the valve head.