DE102009027793A1 - Device for measuring draining amount of compressed water in paper machine, has measuring apparatus comprising microwave sensor and measuring chamber that is communicatively connected with backwater chamber - Google Patents

Abstract

The device has a measuring container for containing fluid whose volumetric flow rate is measured. The container has a backwater chamber (15) and a drainage chamber (14) connected with each other, where the backwater chamber has an inlet (2) for the fluid. A connection opening of an orifice plate (6) is determined and selected such that defined back water is formed in the backwater chamber. A measuring apparatus (8) measures height of the backwater and/or a fluid column, and has a microwave sensor (9) and a measuring chamber that is communicatively connected with the backwater chamber.

Description

The The invention relates to a measuring device for volume flow measurement of liquids or suspensions, in particular the invention a device for the measurement of the dewatering amounts of paper machines.

at Paper production is done by dewatering the paper web at various points in the paper machine, for example in the area of the wire section, the press section or the dryer section. For It is important to the papermaker, the dewatering quantities, that is, the volume flow of the dewatered liquid, to know very well.

When Indicator for the dewatering performance of the press section are the drainage flow meters nowadays become indispensable in the paper industry.

about the determined dewatering performance can be the papermaker the necessary decisions, such as For example, the time of the next one Take a napkin or the next felt cleaning.

Of Furthermore, it is of particular importance to know when a new one Built-in felt reaches its optimum operating condition as the Paper machine only then with the highest production speed can be operated and their too early increase would lead to tearing of the paper web.

moreover it comes with an optimal setting of the drainage services in the individual sections to significant energy savings.

to Measurement of accumulating liquids, including fibrous materials and / or additives may be so-called Dewatering quantity measuring boxes used.

For example The pressed out water of the press section is collected in drainage channels and passes through pipelines to the drainage quantity measuring box. In this, the liquid flow accumulates in front of a panel with defined aperture slot, so depending on the damming height can drain off a defined liquid flow.

By the size of the iris or measuring aperture the amount of water the taps can be adjusted. So change depending on the drainage capacity, the backwater level.

With Help of a pressure transmitter is now the hydrostatic pressure of the back-blocked liquid flow and determines the drainage performance.

The Although measuring method using a pressure transmitter is generally as reliable, but it is relatively easily due to deposits and turbulence to measurement inaccuracies.

In the DE 10 2005 048 053 A1 a generic measuring device will be described.

Of the Invention is therefore based on the object, a device for direct volume flow measurement of liquids or suspensions to further develop the aforementioned type, so that the measurement accuracy and process safety can be improved.

According to the invention the object by a measuring device with the features of the claim 1 solved. The subclaims describe advantageous and particularly expedient embodiments of Invention.

The Device for measuring the volume flow of liquids, especially for the measurement of dewatering quantities in paper machines, consists essentially of a measuring container for receiving a liquid whose volume flow is measured shall be.

In which the measuring container has at least two chambers, one Backflow chamber with an inlet for the liquid and a drain chamber with a drain. Both chambers are with each other connected, wherein the connection opening of a metering orifice, which has a defined opening formed which is selected to be in the backpressure chamber forms a defined backwater.

The Height of the liquid column, which is through forms the backwater is measured and by means of the measured value the flow rate is determined.

advantageously, the measuring device consists of a measuring chamber with the back pressure chamber is communicatively connected, such as preferably a bypass, and a sensor of the level in the measuring chamber measures.

In which the sensor is preferably a microwave sensor using of the radar principle.

• – die Messung berührungslos erfolgt,
• – Eigenschaften des Messmediums (Dichte, Leitfähigkeit, Temperatur, usw) die Messung nicht beeinflussen
• – die Verschmutzungsanfälligkeit sehr gering ist.
• – der Wartungsaufwand sehr gering ist.

By using a microwave sensor in the bypass, the measurement accuracy is significantly improved by:

• - the measurement takes place without contact,
• - Properties of the measuring medium (density, conductivity, temperature, etc.) do not influence the measurement
• - The susceptibility to pollution is very low.
• - The maintenance is very low.

to Separation of air can occur between the inlet and the backpressure chamber additionally an air separation device can be arranged.

In which the Luftabscheidevorrichtung from a chamber with a suction port exists, so that at the inlet a negative pressure can be generated. The measuring device can then also connected to, for example, a pipe sucker become.

The The measuring chamber must also be connected to the vacuum for this purpose so that a communicating connection with the Backflow chamber is created.

The Orifice is preferably designed to be interchangeable is. In addition, this can be an adjustable orifice exhibit.

Of Furthermore, the measuring aperture opening can be designed such that that the outgoing flow rate changes with Backwater level antiproportional changes.

Of the Inlet into the measuring device takes place essentially from above or in the upper area of the backwater chamber or in the upper area the air separation chamber.

Of the Drain is in the drain chamber below the aperture attached, preferably in the bottom region of the drain chamber.

The Measuring chamber can be outside or inside the backpressure chamber be positioned and parallel to the measuring chamber may additionally a bypass sight glass be positioned, which then also communicates connected to the measuring chamber.

The solution according to the invention is hereinafter explained with reference to figures. In detail is the following shown:

1 shows a measuring device according to the invention for liquids in section;

2 shows the measuring device of 1 from a different perspective

3 shows a sectional view of a measuring device according to the invention for a suction device with liquid-air separation device.

4 shows an example of some apertures

1 shows a measuring device according to the invention for liquids in section. The measuring device shown here is suitable for the volume flow measurement of liquids such. For example, the press water from a press nip a paper machine.

The press water passes through the tube attached to the upper cover to the inlet 2 into the interior of the measuring container 1 , There it first meets a baffle plate and runs from there into the backwater chamber 15 , In the backwater chamber 15 the press water collects and accumulates until it reaches the opening in the metering orifice 6 reached, through which the liquid from the back pressure chamber 15 in the drainage chamber 14 can flow.

The Orifice plate extends in the vertical direction, for example in the form of a rectangle that is taller than wide is. The orifice can also be different shape exhibit.

The overflow level results from the distance between the backflow chamber floor and Unterkannte the Meßblendenöffnung.

If the liquid supply continues to reach the height of the lower edge of the orifice, the liquid begins via the orifice of the back pressure chamber 15 in the drainage chamber 14 to flow, wherein the liquid level continues to increase until the outflowing from the Meßblendenöffnung liquid stream corresponds to the liquid flow over the inlet 2 accrues.

at a balance between the inflowing liquid volume flow and the outflowing liquid volume flow the liquid level stays stationary on one Height.

In 2 is the measuring device of 1 shown from a different perspective, so that the measuring device is more visible.

For measuring the height of the liquid level is the measuring chamber 13 with the backwater chamber 15 communicating so connected that in the measuring chamber 13 always the same level is available as in the back pressure chamber 15 , By separating the measuring chamber 13 from the backwater chamber 15 is achieved that the liquid surface for the measurement of the filling level is much quieter or calms down faster and so vibration does not affect so much on the liquid surface in the measuring chamber.

The filling level is in the measuring chamber 13 measured by a sensor without contact, preferably a microwave sensor whose transmitter emits pulses to the liquid surface of the the liquid surface are reflected and received by an antenna system again.

Parallel to the measuring chamber 13 In addition, a bypass sight glass may be attached.

The upper area of the backflow chamber 15 and the upper portion of the measuring chamber and the sight glass are connected to the atmospheric pressure.

To Cleaning purposes are maintenance openings to each chamber available.

3 shows a sectional view of a measuring device according to the invention for a suction device with liquid-air separation device. This version is required to measure volume flows of liquids that need to be extracted by means of a vacuum. So z. B. sucked by means of tube suckers, the water from the felt belts. The suction creates a liquid-air mixture that must be separated again in order to be able to measure the liquid volume flow and to ensure that no liquid reaches the vacuum pump.

For the separation of liquid and air is the back pressure chamber 15 , the measuring chamber 13 and the drainage chamber 14 an air separation device 16 upstream.

In the measuring container 1 is thus an additional Luftabscheidekammer 18 available. In the upper part of the air separation chamber 18 is from the side of the inlet 2 connected and from above the vacuum supply.

The air-liquid mixture occurs in the upper region z. B. tangentially in the Luftabscheidekammer 18 one and the liquid is by the air flow along the spiral guide plate in the direction of the bottom plate of Luftabscheidekammer 18 guided. The resulting centrifugal forces and gravity separate the liquid from the air. The air then flows through the down to the lower part of the Luftabscheidekammer 18 reaching suction tube from the measuring container.

The liquid flows through an opening in the bottom plate of the air separation chamber 18 in the backwater chamber 15 and from there through the aperture 7 into the drainage chamber 14 and then through the drain 3 aspirated. A pump prevents the false air through the drain 3 gets into the measuring container.

The measuring device 8th is also in this version with the back pressure chamber 15 communicatively connected. This is the measuring chamber 13 once with the lower section of the backflow chamber 15 and once with the upper part of the backflow chamber 15 , which is above the maximum possible backwater, connected. This ensures that there is always the same pressure in the backflow chamber 15 and the measuring chamber prevails and so the liquid level is always identical, so the chambers communicate with each other.

In the 4 some aperture shapes are shown. Due to the different shapes, the flow rate can be influenced so that the change in the backwater level leads to clear measurement results. So it is possible to design the opening so that at critical backwater heights results in a clear backwater height change.

LIST OF REFERENCE NUMBERS

1

measuring Cup

2

Intake

3

procedure

4

partition wall

5

baffle

6

orifice

7

Measuring aperture

8th

measuring device

9

gauge

10

Bypass sight glass

11

connection

12

maintenance opening

13

measuring chamber

14

drain chamber

fifteen

back pressure chamber

16

Luftabscheidevorrichtung

17

guide plate

18

air separation chamber

19

suction

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 102005048053 A1 [0012]

Claims (13)

Device for the volume flow measurement of liquids, in particular for the measurement of dewatering quantities in paper machines, with a measuring container ( 1 ) for receiving a liquid whose volume flow is to be measured, wherein the measuring container ( 1 ) has at least two chambers, a back pressure chamber ( 15 ) with a feed ( 2 ) for the liquid and a drain chamber ( 14 ) with a sequence ( 3 ), which are interconnected; wherein the connection opening of a measuring orifice ( 6 ), which has a defined opening ( 7 ) is determined, which is chosen so that forms a defined backwater in the back pressure chamber; and a measuring device which measures the height of the backwater or the height of the liquid column, characterized in that the measuring device ( 8th ) from a measuring chamber ( 13 ) connected to the backflow chamber ( 15 ) is communicatively connected and consists of a sensor. Device according to claim 1, characterized in that in the measuring chamber ( 13 ) is provided a sensor for measuring the height of the liquid column. Device according to one of claims 1 or 2, characterized in that the sensor is a microwave sensor ( 9 ). Device according to one of claims 1 to 3, characterized in that between the inlet ( 2 ) and the backflow chamber ( 15 ) an air separation device ( 16 ) is arranged. Apparatus according to claim 4, characterized in that the Luftabscheidevorrichtung ( 16 ) from an air separation chamber ( 18 ) and a suction air connection ( 19 ), so that at the inlet ( 2 ) and thus also in the measuring container ( 1 ) A negative pressure can be generated. Device according to one of claims 1 to 5, characterized in that the measuring diaphragm ( 6 ) is interchangeable. Contraption ( 1 ) according to one of claims 1 to 6, characterized in that the measuring diaphragm ( 6 ) an adjustable measuring opening ( 7 ) having. Device according to one of claims 1 to 7, characterized in that the measuring aperture ( 7 ) is designed so that the running volume flow changes with antiproportional changing with backwater height. Device according to one of claims 1 to 8, characterized in that the inlet ( 2 ) substantially from above into the backflow chamber ( 15 ) or in the upper region of the air separation chamber ( 18 ) he follows. Device according to one of claims 1 to 9, characterized in that the sequence ( 3 ) in the drain chamber ( 14 ) is mounted below the aperture, preferably in the bottom region of the drain chamber. Device according to one of claims 1 to 5, characterized in that the measuring chamber ( 13 ) outside the backflow chamber ( 15 ) is positioned. Device according to one of claims 1 to 5, characterized in that the measuring chamber ( 13 ) within the backflow chamber ( 15 ) is positioned. Device according to one of claims 11 to 12, characterized in that parallel to the measuring chamber ( 13 ) a bypass sight glass ( 10 ) and communicating with the measuring chamber ( 13 ) connected is.

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