DE4341492A1 - Pipeline throughput regulating appts. - Google Patents
Pipeline throughput regulating appts.Info
- Publication number
- DE4341492A1 DE4341492A1 DE19934341492 DE4341492A DE4341492A1 DE 4341492 A1 DE4341492 A1 DE 4341492A1 DE 19934341492 DE19934341492 DE 19934341492 DE 4341492 A DE4341492 A DE 4341492A DE 4341492 A1 DE4341492 A1 DE 4341492A1
- Authority
- DE
- Germany
- Prior art keywords
- sensors
- throughput
- ntc
- gases
- fluorine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D7/00—Control of flow
- G05D7/06—Control of flow characterised by the use of electric means
- G05D7/0617—Control of flow characterised by the use of electric means specially adapted for fluid materials
- G05D7/0629—Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means
- G05D7/0635—Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means by action on throttling means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
- G01F1/684—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
- G01F1/688—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow using a particular type of heating, cooling or sensing element
- G01F1/69—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow using a particular type of heating, cooling or sensing element of resistive type
- G01F1/692—Thin-film arrangements
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Engineering & Computer Science (AREA)
- Automation & Control Theory (AREA)
- Measuring Volume Flow (AREA)
Abstract
Description
Die vorliegende Erfindung betrifft eine Vorrichtung zur Regelung (Konstant haltung) des Durchsatzes von Gasen oder Flüssigkeiten in diese führenden Leitungen.The present invention relates to a device for control (constant maintenance) of the throughput of gases or liquids in these leading Cables.
Zur Regelung des Durchsatzes strömender Flüssigkeiten ist es bekannt, in einer Bypassleitung zwei oder mehrere beheizte Sensoren anzuordnen, wobei unter schiedliche Strömungsgeschwindigkeit zu unterschiedlicher Sensortemperatur führt, d. h. daß diese proportional zum Durchsatz ist. Umgekehrt ist es auch mög lich, aus der zum Konstanthalten der Sensorentemperatur benötigten Energie auf die Strömungsgeschwindigkeit zu schließen.To regulate the throughput of flowing liquids, it is known in a Bypass line to arrange two or more heated sensors, under different flow rates at different sensor temperatures leads, d. H. that it is proportional to the throughput. Conversely, it is also possible Lich, from the energy required to keep the sensor temperature constant to close the flow rate.
Diese Sensoren weisen jedoch den Nachteil auf, daß sie in aggressiven Medien nicht eingesetzt werden können, da sie schnell korrodieren.However, these sensors have the disadvantage that they are in aggressive media cannot be used because they corrode quickly.
Die vorliegende Erfindung hat sich daher die Aufgabe gestellt, eine Regelungs vorrichtung zu schaffen, die auch in Gegenwart von aggressiven Medien störungs frei arbeiten.The present invention has therefore set itself the task of a control device to create the interference even in the presence of aggressive media work freely.
Die Lösung dieser Aufgabe gelingt bei einer Vorrichtung zur Regelung des Durch satzes von Gasen oder Flüssigkeiten in diesen führenden Rohrleitungen, insbe sondere zur Dosierung von aggressiven Gasen wie Fluor oder Chlor, wobei im gasführenden System Sensoren angeordnet sind, die ein Signal abgeben, das über einen Rechner auf ein den Durchsatz veränderndes Stellglied einwirkt erfindungsgemäß dadurch, daß als Sensoren in der Rohrleitung NTC-Wider stände angeordnet sind, die mit einem gegen das strömende Medium inerten Kunststoff ummantelt sind.This object is achieved with a device for regulating the through set of gases or liquids in these leading pipelines, esp special for the dosing of aggressive gases such as fluorine or chlorine gas-carrying system sensors are arranged that emit a signal that acts on a control element which changes the throughput via a computer according to the invention in that as sensors in the pipeline NTC-Wider Stands are arranged, which are inert with one against the flowing medium Are plastic coated.
Die Erfindung macht dabei von der Tatsache gebrauch, daß NTC-Widerstände (negative temperature coefficient) ihren Widerstand mit der Temperatur ändern. Überraschenderweise werden auch dann für die vorliegenden Zwecke, d. h. für die Erfassung geringer Strömungsunterschiede brauchbare Signale erhalten, wenn man die NTC′s mit einer Kunststoffschicht versieht, die gegen aggressive Medien inert ist.The invention makes use of the fact that NTC resistors (negative temperature coefficient) change their resistance with temperature. Surprisingly, even for the present purposes, i.e. H. For the detection of small flow differences receive useful signals, if you provide the NTC’s with a plastic layer that protects against aggressive Media is inert.
Besonders gut reproduzierbare Werte werden erhalten, wenn zwei Sensoren hin tereinander angeordnet und deren Temperaturdifferenz bzw. die Differenz der Widerstände als Regelgröße verwendet.Values that are particularly reproducible are obtained when two sensors are present arranged one above the other and their temperature difference or the difference of Resistors used as a control variable.
Die Ummantelung der NTC′s besteht aus einem Fluor enthaltenden Kunststoff, insbesondere aus Polyvinylidenfluorid (PVDF) oder aus Polytetrafluorethylen (Teflon).The coating of the NTC’s consists of a fluorine-containing plastic, in particular from polyvinylidene fluoride (PVDF) or from polytetrafluoroethylene (Teflon).
Besonders gute reproduzierbare Werte werden erfindungsgemäß erhalten, wenn man die Widerstände in engem Abstand zueinander anordnet, vorzugsweise (stromab) in Abständen zwischen 0,1 bis 0,5 mm. Als Beschichtungsstärke wer den Materialdicken von etwa 0,1 bis 0,3, vorzugsweise von 0,2 mm verwendet, da diese Schichtstärken das Meßergebnis nur proportional geringfügig ändern.According to the invention, particularly good reproducible values are obtained if the resistors are arranged close to one another, preferably (downstream) at intervals between 0.1 to 0.5 mm. As a coating thickness who the material thicknesses of about 0.1 to 0.3, preferably 0.2 mm, used these layer thicknesses only slightly change the measurement result proportionally.
Ganz besonders bevorzugt sind die Widerstände mit Stromstärken von etwa 30 Milliampere aufgeheizt, was zu deren Temperatur von etwa 60 bis 70°C führt. In diesem Temperaturbereich sprechen die NTC′s besonders sensibel an, so daß überraschend geringe Durchsatzänderungen erfaßt werden können.The resistors with currents of about 30 are very particularly preferred Milliamps heated, which leads to their temperature of about 60 to 70 ° C. In this temperature range are particularly sensitive to the NTC's, so that Surprisingly small changes in throughput can be detected.
Anhand der beiliegenden Figur wird die vorliegende Erfindung näher erläutert.The present invention is explained in more detail with reference to the attached figure.
In einer Leitung für Flüssigkeiten oder insbesondere für Gase sind zwei NTC′s 2 und 3 in Strömungsrichtung dicht hintereinander angeordnet, wobei der Abstand a, d. h. die Spaltbreite 0,2 mm beträgt. Der Durchmesser der NTC′s liegt bei 3 mm, die Stärke des Kunststoffmantels 4 beträgt 0,2 mm. Die NTC′s 2, 3 sind durch Anlegen eines Stromes einer Stärke von etwa 30 mA auf eine Temperatur von ca. 60-70°C gebracht.In a line for liquids or in particular for gases, two NTCs 2 and 3 are arranged closely one behind the other in the direction of flow, the distance a, ie the gap width being 0.2 mm. The diameter of the NTC's is 3 mm, the thickness of the plastic jacket 4 is 0.2 mm. The NTC's 2 , 3 are brought to a temperature of about 60-70 ° C by applying a current of a strength of about 30 mA.
Über die elektrischen Leitungen 5, 6 werden die Widerstände (ca. 5 Kiloohm) erfaßt und über eine Wheatstone-Brücke und Mikroprozessoren digital in einer Rechnereinheit 7 verarbeitet. Über die Steuerleitung 8 wird das als Differenzwert der beiden NTC′s 2, 3 ausgewertete Signal einer Steuereinheit 9 zugeführt, die einen Stellmotor für ein Ventil oder eine Blende umfaßt, die proportional zum gemessenen Widerstand (bzw. deren Differenz) geöffnet oder geschlossen wer den, um in der stromab liegenden Leitung 1′ den Durchsatz konstant zu halten.The resistances (approx. 5 kilohms) are detected via the electrical lines 5 , 6 and digitally processed in a computer unit 7 via a Wheatstone bridge and microprocessors. Via the control line 8 , the signal evaluated as the differential value of the two NTCs 2 , 3 is fed to a control unit 9 , which comprises a servomotor for a valve or an orifice which opens or closes in proportion to the measured resistance (or its difference) to keep the throughput constant in the downstream line 1 '.
Grundsätzlich ist auch die Verwendung eines einzigen Sensors möglich, der Wärme an das strömende Medium in Abhängigkeit zur Strömungsgeschwindigkeit abgibt und damit seine Temperatur und seinen Widerstand ändert.In principle, the use of a single sensor is also possible Heat to the flowing medium depending on the flow rate releases and thus changes its temperature and resistance.
Von besonderem Vorteil ist der einfache Aufbau. Die Strömungsverhältnisse zwi schen den Sensoren können leicht laminar gehalten werden, die Vorrichtung ist selbsteichend.The simple structure is particularly advantageous. The flow conditions between The sensors can be kept slightly laminar, the device is self-adjusting.
Weiterhin ist eine mit sehr hoher Genauigkeit arbeitende Regelung, d. h. Kon stanthaltung vorgegebener Werte möglich.Furthermore, a control working with very high accuracy, i. H. Con Maintaining specified values possible.
Claims (8)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19934341492 DE4341492A1 (en) | 1993-12-06 | 1993-12-06 | Pipeline throughput regulating appts. |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19934341492 DE4341492A1 (en) | 1993-12-06 | 1993-12-06 | Pipeline throughput regulating appts. |
Publications (1)
Publication Number | Publication Date |
---|---|
DE4341492A1 true DE4341492A1 (en) | 1995-06-08 |
Family
ID=6504266
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE19934341492 Withdrawn DE4341492A1 (en) | 1993-12-06 | 1993-12-06 | Pipeline throughput regulating appts. |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE4341492A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ITVI20100172A1 (en) * | 2010-06-18 | 2011-12-19 | Extraflame S P A | DEVICE FOR DETECTING THE AIR FLOW ENTRY INTO APPLIANCES FOR HEATING THE ENVIRONMENTS AND ITS METHOD |
EP3196659A1 (en) | 2016-01-19 | 2017-07-26 | Siemens Aktiengesellschaft | Flow sensor and method for producing the same |
-
1993
- 1993-12-06 DE DE19934341492 patent/DE4341492A1/en not_active Withdrawn
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ITVI20100172A1 (en) * | 2010-06-18 | 2011-12-19 | Extraflame S P A | DEVICE FOR DETECTING THE AIR FLOW ENTRY INTO APPLIANCES FOR HEATING THE ENVIRONMENTS AND ITS METHOD |
EP3196659A1 (en) | 2016-01-19 | 2017-07-26 | Siemens Aktiengesellschaft | Flow sensor and method for producing the same |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
8139 | Disposal/non-payment of the annual fee |