EP2756219A2

EP2756219A2 - Condensate drainage means with fault monitoring

Info

Publication number: EP2756219A2
Application number: EP12772243.7A
Authority: EP
Inventors: Johannes Sinstedten; Herbert Schlensker
Original assignee: Beko Technologies GmbH
Current assignee: Beko Technologies GmbH
Priority date: 2011-09-08
Filing date: 2012-09-07
Publication date: 2014-07-23
Also published as: BR112014004793A2; CN103827569A; US20140230905A1; JP2014529045A; JP6019122B2; DE102011053411A1; DE102011053411B4; WO2013034674A2; KR20140058681A; WO2013034674A3

Abstract

The invention relates to a method for fault monitoring of a discharge valve (16) of a condensate drainage means (1) of a pressurized gas system, wherein the condensate drainage means (1) has a discharge valve (16), which discharge valve has a valve element (19) which can be actuated by a control circuit (15) and which can be moved between a closed position and an open position and which serves, in the open position thereof, to discharge pressurized condensate from the pressurized gas system via a discharge region (18), arranged downstream of the valve element (19), of the condensate drainage means and, in the closed position thereof, to maintain the pressure in the pressurized gas system, wherein the method has: a closing step, in which the control circuit (15) triggers a closing movement of the valve element (19) in the direction of the closed position, and/or an opening step, in which the control circuit (15) triggers an opening movement of the valve element (19) in the direction of the open position; and a respectively subsequent step for monitoring the closed position or open position of the valve element (19). The method according to the invention is characterized in that, in the step for monitoring the closed position, a non-closed position is detected on the basis of a discharge flow of the pressurized gas, of the condensate or of mixtures thereof in the discharge region (18) or at the valve element (19), or in the step for monitoring the open position, a discharge flow of the pressurized gas, of the condensate or of mixtures thereof in the discharge region (18) or at the valve element (19) is detected.

Description

Condensate drain with fault monitoring

The present invention is a method for disturbance monitoring a shut-off valve of a Kondensatabieiters and a suitably equipped Kondensatabieiter.

In compressed-gas systems, such as compressed-air systems, condensate consisting essentially of water and oil arises, for example, from the lubricant of the compressors and the moisture content of the gas. This condensate usually adversely affects the intended use of the compressed gas system due to soiling, clogging and corrosion. Therefore, it must be collected and drained from time to time from the self-contained pressurized gas system, preferably without gas or compressed air being lost in large quantities and the pressure in the system significantly decreasing. It is known to perform such bleeding operations at predetermined time intervals. Ideally, however, such draining operations are caused depending on the level of a collection area provided for the condensate. For level measurement a variety of methods and procedures are known. However, there is the problem of not always reliable operation of the drain valve, since its valve element is subject to wear, for example. But also pollution such as the deposition of condensate residues can lead to the desired valve position not setting. While the question whether the opening position at which condensate is discharged is achieved completely or only partially is comparatively uncritical, it is of great importance that the closed position, in which the valve element sealingly abuts against its associated valve seat, reliably reaches so that leakage does not lead to unwanted pressure drop. At present, however, such malfunctions are only noticed, if at all, indirectly by the pressure drop, usually too late or not at all, and are only turned off when the condensate drain is exchanged routinely during maintenance intervals. Consequently, there is a need to detect such a malfunction as early as possible to avoid unnecessary pressure drop. It is therefore an object of the present invention to provide a method for the reliable monitoring of the failure of a condensate drain, so that a more reliable operation of a condensate drain is ensured. Furthermore, a correspondingly improved Kondensatabieiter is provided. This object is achieved by a method having the features of claim 1 and by a Kondensatabieiter according to the independent claim. Advantageous embodiments are the subject of the dependent claims. It should be noted that the features listed individually in the patent claims can be combined with one another in any technologically meaningful manner and show further embodiments of the invention. The description, in particular in connection with the figures, additionally characterizes and specifies the invention.

The inventive method is provided for monitoring the failure of a drain valve of a Kondensatabieiters. The Kondensatabieiter invention serves to drain condensate from a compressed gas system, in particular compressed air system. Condensate in the context of the invention means essentially consisting of liquid constituents accumulations in the compressed gas system. Condensate essentially comprises water resulting from the moisture content of the gas and oil due, for example, to the lubricant of the compressors.

The inventive Kondensatabieiter has a drain valve, the egg n a controllable by a control circuit, between a closed position and an open position movable valve element has in its open position pressurized condensate from the pressurized gas system ü be reinendem Ve n ti lelementna ch g esc hal tete From this point on, it is necessary to drain the condensate drain and to keep the pressure in the compressed gas system in its closed position. For example, in the closed position, the valve member sealingly abuts an associated valve seat so as to maintain the pressure in the compressed gas system. The method according to the invention comprises a closing step, in which the control circuit at least triggers a closing movement of the valve element in the direction of the closed position. To check whether the closed position is reached and / or held, a subsequent step for monitoring the closed position of the valve element is also provided. This monitoring step becomes, for example, once, in several times Sequence or at least sections continuously, for example, until an opening step in which the control circuit triggers an opening movement of the valve element in the direction of the open position performed. Preferably, the monitoring step is performed continuously for the duration while the control circuit is intended to initiate and maintain a closed position of the valve element.

The method according to the invention is characterized in that, in the step of monitoring the closed position, a non-closed position is determined by a bleed flow, which can thus be referred to as leakage flow, of the compressed gas, condensate or mixtures thereof in the downstream of the valve element drain region or if possible directly at the valve element d identifies wi rd. Le cka g est rö mungmei nt e in a compressed gas and / or condensate-containing flow, which occurs due to the malfunction of the shut-off valve in its closed position, for example because the closed position of the valve element is not achieved or insufficiently seals the valve element. The detection of the malfunction has the advantage that an improper functioning of the condensate drain can be detected at an early stage, and thus the precautionary replacement of parts of the condensate drain can be omitted in a predefined set of parameters. The detection of the leakage flow in the discharge area of the condensate drain, for example almost directly on the valve element, achieves a very reliable malfunction detection. The fault monitoring according to the invention has the advantage that now only in case of failure maintenance or replacement of components of Kondensatabieiters can be made. A performed from the actual wear and disturbance behavior performed at predetermined time intervals maintenance can be advantageously eliminated. The latter has the disadvantage that a maintenance only by time, d. H. is performed on mere suspicion and without real necessity, with the disadvantage that unnecessarily pressure in the printing system must be drained and subsequently rebuilt. The known procedure, namely to carry out the maintenance at predetermined service intervals, is also not oriented to the actual load. For example, it is quite possible that by more than expected opening and closing movements of the valve, a failure before time the regular maintenance exchange falls and is not noticed. The fault monitoring according to the invention thus has the advantage that faults are detected early and unnecessary pressure losses are avoided. Although the method according to the invention is intended primarily for detecting a leakage flow after effecting a closed position of the valve element, the invention also relates to a method in which a monitoring after an opening step, in which the control circuit triggers an opening movement of the valve element in the direction of opening position, takes place whether a bleed flow is to be detected in the bleed area or, if possible, on the valve element. It can thus be checked whether the discharge operation is or has been carried out successfully. Furthermore, the invention relates to a combination of both methods, namely the closed position monitoring and the opening position monitoring. In particular, the opening position monitoring has the advantage that, after a malfunction in which no discharge takes place after detection of a condensate level to be discharged, if necessary after repeated discharge attempts, without visual or. Functional control can be "designed", as far as a successful discharge process is finally detected.

The inventive method has next to the possibility of membrane failure monitoring in conjunction with another sensor, for example, for the level monitoring of the condensate collection area and / or monitoring the valve control also has the advantage that in conjunction with this further sensor further monitoring the function of the entire Kondensatabieiters and / or the upstream and downstream components of the printing system is made possible by plausibility check.

For example, the detection or non-detection of the aforementioned outlet flow after performing the opening step, in which the valve element is moved into the open position, can be used to perform a function check of the filling level monitoring or vice versa. If, for example, fill level monitoring detects a condensate level to be drained off and no discharge flow is detected after the opening step has been initiated, this indicates an optionally mechanical one Fault or contamination in the control of the valve or for a total pressure drop in the compressed gas system.

According to a preferred embodiment, the discharge flow is detected due to the flow pressure caused thereby. For example, a switch is provided, the movable actuating member changes its position by the action of the Ablassströmung and wherein this position change causes a change in the switching state of the switch. Thus, a cost-effective detection sensor can be realized.

In a further advantageous embodiment, the Ablassströmung is detected due to the temperature drop caused thereby, whereby a very reliable and störungsunanfällige detection of the accident is achieved. For example, at least one temperature sensor is provided which detects the cooling caused during the expansion of the compressed gas. For more accurate or reliable detection of the temperature drop, a further or a plurality of further temperature sensors is provided which determine the ambient temperature and / or the compressed gas or condensate temperature. Alternatively, according to a further embodiment, a calorimetric determination of the change in heat quantity of the discharge flow during unintentional discharge is provided.

The discharge region is preferably heated with a predetermined amount of heat, for example electrically heated, and the discharge flow is detected on the basis of the resulting temperature increase in the discharge region.

According to a preferred embodiment, not only a qualitative but also a quantitative detection of the temperature change takes place. Thus, the composition of the discharge or leakage flow can be determined on the basis of the value of the temperature drop or the temperature increase. For example, in the case of a predominantly liquid-containing bleed flow, a greater temperature increase or a lower temperature drop is to be expected, and with a predominantly gas-containing bleed flow a lower temperature increase or a greater temperature drop is to be expected, so that conclusions can be drawn about the composition and a more accurate fault identification. possible. The quantitative measurement thus has the advantage that, furthermore, any desired discharge process can be monitored. Based on the expansi- Onsbedingten temperature changes are conclusions on the pressure of the compressed gas system and its composition possible.

According to a preferred, because particularly störunanfälligen, embodiment is caused by the leakage flow, a movement of a detection sensor whose movement and / or position is detected magnetically or inductively. For example, a permanent magnetic detection transmitter is provided, the movement of which is detected by means of an induction coil. Preferably, in the step of monitoring the closed position upon detection of the non-closed position by the control circuit, an optical and / or acoustic disturbance signal is initiated so as to cause maintenance of the condensate drain, for example. The invention further relates to a Kondensatabieiter for a compressed gas system. According to the invention, the latter has the following: a control circuit, a discharge valve which has a valve element which is actuated by the control circuit and which is movable between a closed position and an open position. The valve element is provided to discharge in its opening position pressurized condensate from the pressurized gas system via the discharge region of the condensate drain and to keep the pressure in the compressed gas system in its closed position. The inventive Kondensatabieiter further comprises a detection device for detecting a Ablassströmung in the discharge area. According to the invention the control circuit of the Kondensatabieiters is designed to carry out the method described above.

The detection of the malfunction has the advantage that an improper functioning of the condensate drain can be detected at an early stage and thus the precautionary replacement of parts of the condensate drain in fixed, predetermined heat exchanges can be omitted. The detection of the leakage flow or discharge flow almost directly on the valve element achieves a very reliable malfunction detection. To avoid repetition, reference is made to the equally valid advantages of the method according to the invention. Preferably, the discharge or leakage flow is detected by a sensor comprising at least one temperature sensor and / or a flow pressure sensor. Preferably, the flow pressure sensor comprises a biased against the direction of Ablassströmung or leakage flow, in the direction of Ablassbzw. Leakage flow movable magnetic or magnetizable detection transmitter whose movement and / or position is detected inductively or magnetically.

Preferably, the drain valve is a diaphragm valve. The valve element is thus a membrane, for example made of an elastic plastic. Diaphragm valves are ideal for regulating and shutting off volume flows. Since only the valve body and the membrane are in contact with the compressed gas or the condensate, there are only slight wear problems.

It is preferably provided that compressed gas is applied to the drain valve by means of a control valve in order to move the drain valve at least into the open position.

The invention and the technical environment will be explained in more detail with reference to FIGS. It should be noted that the figures show a particularly preferred embodiment of the invention, but this is not limited thereto. They show schematically:

Fig. 1 is a sectional view of a generic Kondensatabieiters, in which the inventive method is used;

Fig. 1 shows a condensate drain 1 according to the invention for a compressed air system in a sectional view. Condensate 2, which is obtained during the compression of the compressed air, is fed via a feed line 3 to the Kondensatabieiter 1. The condensate 2 is substantially condensed moisture of the ambient air, which sucks a compressed air compressor, not shown here. It also has regularly oily and particulate metallic components. The condensate 2 collects in a condensate collecting region 4 and, after reaching a defined fill level 5, is drained via a drain valve 16 provided in the drain line 6 and the drain region 18. In the in Fig. 1, the drain valve 16 is designed as a diaphragm valve, i. H . the drain valve 16 has a membrane as a valve element 19, which in its in Fig. In FIG. 1 closed sealingly with a valve seat, so as to close the drain line 6.

It is a capacitive sensor 7 for quantitative measurement of the level in the condensate collection area 4 is provided. The sensor system 7 comprises at least one measuring capacitor 8, which has a continuously variable capacitance as a function of the level of the condensate 2 in the condensate collecting region 4. The capacitive measurement thus detects the filling state of the condensate collector 4 by the change in the electrical capacitance when condensate 2 flows as a dielectric kum. The measuring capacitor 8 forms an electromagnetic measuring field between a first dedicated capacitor electrode and a second counter electrode provided by the wall of the condensate collecting region 4. Even with heavy contamination, for example due to rust from the compressed air lines or oil from the air compressors, the device shown is very reliable. The sensor 7 is arranged so that even with flooded condensate collection area 4 a non-wetted by the condensate and thus clean zone 9 remains to avoid erroneous measurements caused, for example, by coatings that can lead to a metrological short circuit.

The clean zone 9 is defined by a dive-bell-like recess 11. When the collecting area 4 is completely flooded-that is, beyond the maximum intended level 5 -containing the clean zone 9 or the diver-bell-like recess 11, no condensate 2 can penetrate. In the clean zone 9 above the maximum intended level 5 and the inlet of the compressed air line 13 is provided. The branched off compressed air is used to actuate the drain valve 16 and the holding of the drain valve in its closed position. For this purpose, the electromagnetic control valve 17 is provided, which ensures in the position shown that compressed air is applied to the membrane 19 of the drain valve 16, that the drain line 6 is closed and no condensate 2 can be drained. The electric Magnetic control valve 17 comprises a coil 12 and a permanent magnetic armature 10, which by the flow of a current flowing through the coil actuating current from a rest position, for example, in FIG. 1 shown in the closed position of the drain valve 16 corresponding position, is moved to a desired position. The rest position results from the fact that the armature 10 has at one of its end faces an elastic sealing material and whose gravity and compressed air supported concern the end face to a valve seat 11, a closure of the compressed air discharge line 14 is effected so that the pressurization of the drain valve 16 is maintained , For controlling the electromagnetic control valve 17 and thus of the shut-off valve 16, an electronic control circuit 15 is provided. In the closing step, a sufficient drop in a holding current ensures that the armature 10 with gravity and with the compressed air of the line 13 against a lower stop in a Schl ießstel lungs laps in which he closes the compressed air discharge line 14, but at the same time compressed air above the diaphragm 19 abuts, and urges them into the closed position. After initiation of this closing movement of the diaphragm 19 Druckverl uste be avoided by leakage flow in the compressed gas system. To check whether a leakage flow occurs on the valve element 19, because this has not reached its closed position, for example, no longer maintains it, for example because of wear-related damage, a temperature sensor 20 is provided. By means of the temperature sensor 20, the control circuit 15 is able to detect a temperature drop, which is due to the expansion of the unwanted compressed gas outlet (leakage flow). This monitoring is carried out by the control circuit 15 and in the case of the detection of a leakage flow, a fault signal is generated, which is displayed optically or acoustically.

Claims

claims

Method for monitoring the malfunction of a drain valve (16) of a condensate drain (1) of a compressed gas system, wherein the condensate drain (1) has a drain valve (16) which can be actuated by a control circuit (15) between a closed position and an open position movable valve element (19) in order to discharge in its open position pressurized condensate from the compressed gas system via a behind the valve element (19) arranged drainage area (18) and to maintain the pressure in the Druckgassystem in its closed Stel development, the method comprising: a closing step, wherein the control circuit (15) triggers a closing movement of the valve element (19) in the direction of the closed position;

a subsequent step for monitoring the closed position of the valve element (19), characterized

in the step for monitoring the closed position, a non-closed position is detected by means of a discharge flow of the compressed gas, the condensate or mixtures thereof in the discharge region (18) or on the valve element (19).

Method for monitoring the malfunction of a drain valve (16) of a condensate drain (1) of a compressed gas system, wherein the condensate drain (1) has a drain valve (16) which can be actuated by a control circuit (15) between a closed position and an open position movable valve element (19) in order to discharge in its open position pressurized condensate from the compressed gas system via a drainage area (18) arranged behind the valve element (19) and to maintain the pressure in the compressed gas system in its closed position, the method comprising: an opening step in which the Control circuit (15) triggers an opening movement of the valve element (19) in the direction of the open position;

a subsequent step for monitoring the opening position of the valve element, characterized in that, in the step of monitoring the open position, a discharge flow of the compressed gas, of the condensate or mixtures thereof in the discharge region (18) or on the valve element (19) is detected.

3. A fault monitoring method according to one of the preceding claims, wherein the discharge flow is detected due to the flow pressure caused thereby.

A disturbance monitoring method according to any one of the preceding claims, wherein the purge flow is detected due to the temperature drop caused thereby.

5. A method for monitoring interference according to one of the preceding claims, wherein is heated with a predetermined amount of heat, the discharge region and the discharge flow is detected on the basis of the resulting increase in temperature in the drain region.

6. The method for fault monitoring according to one of the two preceding claims, wherein the composition of the discharge flow is determined on the basis of the value of the temperature drop or the temperature increase.

7. A fault monitoring method according to one of the preceding claims, wherein the discharge flow causes a movement of a detection transmitter whose movement and / or position is detected magnetically or inductively.

8. A fault monitoring method according to one of the preceding claims, wherein in the step of monitoring the closed position upon detection of the discharge flow by the control circuit an optical and / or acoustic fault alarm is initiated.

9. Kondensatabieiter (1) for a compressed gas system, comprising a control circuit (15), a drain valve (16) which controls a controlled by the control unit, between a Schließstel lungs and an open position movable valve element (19) in order to Open position with pressurized condensate from the compressed gas system via a behind the valve element (19) arranged discharge area (18) and umind eat closed position to maintain the pressure in the compressed gas system, and a detection device (20) for detecting a Ablassströmung the valve element, wherein the control circuit (15 ) is designed to carry out the method according to one of the preceding claims.

10. Kondensatabieiter (1) according to the preceding claim, wherein the detection device comprises at least one temperature sensor (20) and / or a flow pressure sensor.

11. Kondensatabieiter (1) according to the preceding claim, wherein the flow pressure sensor comprises a counter to the direction of the Ablassströmung biased, movable in the direction of Ablassströmung magnetic detection sensor whose movement and / or position is detected inductively or magnetically.

12. Kondensatabieiter according to any one of the preceding claims 9 to

11, wherein the drain valve (16) is a diaphragm valve.

13. Kondensatabieiter according to any one of the preceding claims 9 to

12, further comprising a control valve (17) to move the drain valve (16) by means of the pressurized gas at least in the open position.