Electric ignition for flashpoint tester

A device for igniting a sample arranged in a container for a flashpoint determination test and/or a combustion point determination test. The device has an electric igniter, which has an ignition tip having a partially or completely encapsulated electric wire; and a traversing device, which is configured for traversing the ignition tip of the electric igniter to a defined position within the container.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a national phase application derived from, and claiming the benefit of the filing date of, the German Patent Application DE 10 2018 123 097.4, filed Sep. 20, 2018, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a device for igniting a sample arranged in a container for a flashpoint determination test, further relates to a system for a flashpoint determination, and still further relates to a method of igniting of a sample arranged in a container during a flashpoint determination test.

TECHNOLOGICAL BACKGROUND

Flashpoint test systems are conventionally used for the characterization of combustible materials (e.g. diesel, petrol, kerosene, heating oil), dissolvents, lubricating oils, or chemicals. Per definition, the flashpoint is the lowest temperature, at which vapors (gaseous sample mixed with air) develop under fixed conditions from the liquid to be tested in an open or closed receptacle or crucible in such a quantity that a sample-gas-air-mixture that is flammable by extraneous ignition develops within or outside of the container.

For the determination of the flashpoint and/or the combustion point, preferably according to different standards, a defined quantity of a sample (substance) to be investigated is filled into the container (e.g. measurement crucible), heated in a controlled manner (in particular brought to a predetermined temperature), and stirred if required. Thereby, a mixture of liquid and gaseous sample forms continuously. Starting at a determined temperature, the ignition source is introduced into the container in periodical time and/or temperature intervals in order to ignite the developed liquid-gas-air-sample mixture. If a flame is detected at a particular sample temperature, the burning time of which is less than 5 seconds, then the flashpoint is determined. If the burning time is longer than 5 seconds, then the combustion point of the sample is determined.

Different standard methods are suitable for a flashpoint determination, which methods are characterized substantially by the methods according to i) Pensky-Martens, ii) Abel, iii) Abel-Pensky, iv) Tagliabue, and v) Cleveland.

Conventionally, for igniting the sample to be investigated, an ignition source is used, which comprises for example a, in particular open, glow wire or a coiled glow filament. Alternatively, the ignition may be effected conventionally by a spark gap between two electrodes or by a gas flame.

U.S. Pat. No. 5,176,449 A discloses a device and a method for determining a flashpoint of a liquid or of a solid material, wherein the pressure that is obtained in the measurement chamber after an ignition is measured. At a given temperature, a vapor-air-mixture is ignited, and the pressure increase due to the temperature increase is used as a measure for the size of the flame for determining the flashpoint. The ignition is effected by two electrodes, which generate a spark.

GB 1 279 396 A discloses a system for testing the flashpoint of a flammable product. For igniting, an ignition flame is introduced into a crucible, in which the sample to be investigate is arranged.

U.S. Pat. No. 3,913,600 A discloses a method for monitoring and controlling the composition of a flammable gas mixture, wherein ignitions are performed by an ignition plug. To this end, a high voltage is applied to electrodes of the ignition plug.

U.S. Pat. No. 2,170,056 A1 discloses an apparatus for detecting the concentration of combustible gases. For the ignition, an ignition plug is used, which is operated periodically by a synchronous motor.

GB 185 814 A discloses a system for determining the flashpoint of oils. The vapor is ignited electrically by a spark or by coils. Therein, plural heating coils are arranged underneath a lid of a receptacle. As soon as a coil is heated, the space above the oil is opened towards the atmosphere. The coils are not described in detail in this document.

GB 1 257 323 A discloses a flashpoint detector. An ignition plug is used for igniting. The temperature of the sample is increased until a spark that is generated by an ignition plug ignites the vapor. Therein, the ignition plug is activated by pulses by a generator.

DE 552 706 C discloses a device for testing flammable materials, in particular lubricating oils, wherein a heatable crucible is used for receiving the material to be investigated, and wherein electrically heatable spirals (or coils) that are arranged above the crucible are provided for the ignition of the oil vapors during the flash and combustion point determination as well as for an indication of flame formation.

DE 1 598 631 A1 discloses a measurement device for determining the flashpoint of combustible liquids by a flow-through crucible, which is provided with corresponding heating elements. Therein, the combustible, heated vapor-air-mixture flows along a coiled ignition filament, which ignites the mixture.

The ignition devices known from the state of the art, which are usable for a standardized flashpoint determination or combustion point determination, are sensitive with respect to damage and/or are operable only with corresponding complex drivers (e.g. for the generation of high voltage).

SUMMARY

Thus, there is a need to establish an ignition device, which is usable for a flashpoint determination test, which ensures a reliable ignition of the sample to be investigated, is robust against damages and can be operated by simple driver components. In particular, there is a need to provide a device, which can be operated stably and reliably without high voltage, and is robust against damages.

The object is solved by the subject-matter of the independent patent claims. The dependent claims specify particular embodiments of the present invention.

According to an embodiment of the present invention, there is provided a device for igniting a sample arranged in a container for a flashpoint determination test and/or a combustion point determination test, the device having: an electric igniter, which has an ignition tip having a partially or completely encapsulated electric wire; and a traversing device (or moving device), which is configured for traversing (or moving) the ignition tip of the electric igniter to a (e.g. specifically for electric ignition) defined position within the container.

Overview of Embodiments

The device for igniting may be suitable for a standardized flashpoint determination test and/or combustion point determination test, which may correspond e.g. to one or more of the following standards (or norms) (respectively at least for the versions that are valid at the application date): ASTM D93, DIN EN ISO 2719, GB/T261, IP 34, JIS K 2265, ISO 13736, ISO 1516, ISO 1523, DIN 51755-1 (Abel-Pensky with corresponding accessories); ASTM D56, ASTM D3934, ASTM D3941; ASTM D92, DIN EN ISO 2592, IP 36, IP 403. Embodiments may correspond to further standards that are not mentioned herein. Embodiments of the present invention may support methods according to i) Pensky-Martens and/or ii) Abel and/or iii) Abel-Pensky and/or iv) Tagliabue and/or v) Cleveland.

The flashpoint determination test may be used e.g. for kerosene, oil, generally for hydrocarbon-containing substances, e.g. for quality testing. The flashpoint determination test may be performed e.g. with one of the experimental set-ups, which have been developed by Sir Frederik Abel, Adolf Marten, Berthold Pensky, or Charles J. Tagliabue.

During the flashpoint determination test, the sample to be investigated may be received in a closed or in an open container. Both classes of flashpoint tests may be supported by embodiments of the present invention. Embodiments of the present invention may support test methods, wherein an equilibrium state, a non-equilibrium state or a quick equilibrium state may be present within the container. Non-equilibrium state methods may correspond e.g. to one or more of the standards DIN EN ISO 13736, ASTM D56, DIN EN ISO 2719, ASTM D93, DIN EN ISO 2592, ASTM D92. Equilibrium state methods may correspond to e.g. to one or more of the standards DIN EN ISO 1516, DIN EN ISO 1523, DIN EN 924, ASTM D3941, DIN 53213. Quick equilibrium state methods may correspond e.g. to the standard DIN EN ISO 3679.

During the performing of a flashpoint determination test, the sample to be investigated may be stirred or may not need to be stirred.

During the performing of the flashpoint determination test, the temperature of the sample within the container may be measured at one or more positions (for instance in the gaseous phase and/or the liquid phase). Furthermore, the atmospheric pressure and/or the pressure within the container may be measured, and the measurement results may be corrected accordingly. The flashpoint determination system according to embodiments of the present invention may be configured e.g. to determine flashpoints in a range of from −40° C. to +410° C.

Parts of the electric igniter and/or of the ignition tip may have a substantially cylindrical shape and/or a cylindrical symmetry. The ignition tip can, upon operating the electric igniter, reach e.g. a temperature between 900° C. and 1500° C., in particular between 1300° C. and 1400° C. The highest temperature of the electric igniter may be reached at the ignition tip (in particular at a front end of the ignition tip or close to the front end of the ignition tip). The ignition tip may have a pyramid-shape or a (hemi-) spherical shape. Further geometrical shapes may be possible.

The encapsulation and/or sheathing of the electrical wire may act as a protection of the electric wire within the ignition tip. The electric wire (in particular a coiled ignition filament described in detail below as a part of the electric wire) may be surrounded with metallic or ceramic material for the encapsulation, in particular a liquid-tight and/or a gas-tight encapsulation. Alternatively, the encapsulation and/or sheathing may also be formed of other heat-resistant materials, for example of glass or of a heat-resisting polymer. The encapsulation or sheathing of the electric wire may also result in a substantially homogeneous temperature in the region of the ignition tip. Herein, the ignition tip may be formed by the sheathing and the coiled ignition filament (and possible filling material) arranged therein. The ignition tip may form an end of the electric igniter. Another end of the electric igniter may be attached (e.g. by screw-fastening) to an electric igniter mounting (or fixture). The ignition tip may have e.g. a diameter (in cross-section), which is e.g. two times to five times smaller than a diameter of the other end of the electric igniter. The size of the ignition tip (in particular the cross-sectional diameter thereof) may be selected according to specifications of a, preferably standardized, flashpoint determination test in order to ensure an ignition in a defined spatial region (in particular within the container). The ignition tip may be e.g. bar-shaped or be manufactured from a homogeneous material. In particular, the ignition tip may be manufactured from ceramics, and may be resistant against temperatures up to 1500° C. or even 2000° C.

The position defined for the electric ignition within the container may be defined e.g. by a defined distance underneath a lid of the container, or by a defined distance from the liquid surface of the sample to be investigated to the ignition tip, or by a defined distance from a bottom of the container. Herein, the defined position may be defined in particular by the vertical component thereof, wherein a lateral component is free, such that no necessarily defined lateral position has to be reached. If the defined position within the container of the heat tip is reachable (or approachable) by the traversing device, a standardized flashpoint determination test may be performed.

The container may concern in particular a substantially cylindrical container having a lid. Advantageously, the electric igniter may be operated by applying a voltage (e.g., a direct current or DC voltage) to ends of the electric wire, so that the temperature of the ignition tip rises strongly, so that ignition temperatures may be reached. Thus, a simple operation of the electric igniter may be ensured. By the encapsulation and/or sheathing of the electric wire, the latter may be protected against damage, thus robust. A possible abutting during the traversing by the traversing device thus may not result in a damage of the electric wire.

According to an embodiment of the present invention, the electric wire may be encapsulated and/or surrounded, in particular liquid-tight and/or gas-tight, such that the sample in the liquid and/or in the gaseous state does not directly (or also not indirectly) contact the wire. Thus, on the one hand, a contamination of the sample due to a conventionally occurring contact with the wire may be avoided, and, on the other hand, a contamination or impairment of the wire may be avoided. Thus, the integrity of the wire during the operation may be ensured, so that for example a heating capacity may not be impaired by the sample or components of the sample, and also the structural integrity of the wire may be ensured. Thus, a protection against damage may be ensured, in order to be able to perform a flashpoint determination test reliably.

According to an embodiment of the present invention, the traversing device may be configured to traverse the ignition tip of the electric igniter along a rectilinear traverse distance (in particular without tilt/rotation) (e.g. downwards and upwards), which traverse distance may extend in particular substantially vertically or encloses an acute angle to the vertical.

The rectilinear traversing distance may be free from arcs or curves, such that the ignition tip of the electric igniter may be moved and/or traversed to the defined position (e.g. from a parking position above the container, in particular above a lid of the container) without a tilt and without components of rotational movement. Thus, a simple movement may be enabled, which may simplify the traversing device. If the traverse distance extends substantially vertically or extends enclosing an acute angle to the vertical, the ignition tip may be moved quickly and reliably to the defined position within the container through a relatively small lid opening of a lid of the container. If the rectilinear traverse distance encloses an angle to the vertical, then for example and advantageously a stirrer and/or a temperature and/or measurement head (or sensing element) may be inserted from the above through the lid into the container, without the electric igniter or parts of the electric igniter being in the way. The ignition tip may thus be moved by the traversing device obliquely from above (e.g. through a lid opening) to the defined position within the container.

According to an embodiment of the present invention, the traversing device may further have an electric motor, preferably having a crank drive, which may be coupled to the electric igniter. Upon activation, the electric motor may perform a rotational movement, which may be transformed in a translational movement by the crank drive. A shaft, which may be arranged eccentrically to an axis of the electric motor, may e.g. engage in an oval opening, which may be coupled to an electric igniter mounting (or fixture). Upon operation of the electric motor, the eccentrically arranged shaft may change its position within the oval opening and can touch against inner delimitation areas of the oval opening. By the pressure, which may occur thereby on different delimitation areas of the oval opening, the electric igniter mounting that may be connected thereto may be moved along the rectilinear traverse distance. The movement speed may not necessarily need to be constant e.g. for a constant rotation speed of the motor. In particular, at the beginning and towards the end of the movement of the ignition tip, the speed of the rectilinear movement may be lower than in a middle region between end points of the movement. Thus, also the damaging of components of the device may be avoided. The crank drive may enable a simple conversion of a rotational movement in a translational movement, so that a simple drive may be enabled.

Other mechanical components may be provided instead or in addition to the crank drive in order to convert the rotational movement generated by the motor in a translational movement. To this end, e.g. a screw thread may be provided at the motor shaft, which may engage in a gear rod (or toothed bar) that may be coupled to the electric igniter. Also, pneumatic or hydraulic drives may be possible.

According to an embodiment of the present invention, the traversing device may have an electric igniter mounting (or fixture), by which the electric igniter may be mountable, in particular may be screw-fastenable, and the wire may be electrically connectable (e.g. with a driver) to the wire, and may be encapsulated and/or sheathed by a housing by the wire. Thus, flexible cables, which may conventionally lie open, may be avoided in order to thus possibly simplify a handling or avoid in particular a cable mess, or cable knottings (“cable spaghetti”), or a damage of cables. The electric igniter may be fastened with a screw or screws e.g. to an electric igniter mounting, wherein at the same time connecting contacts (at least two connecting contacts) of the wire and/or two wire ends may be connected electrically to electrical contacts within the electric igniter mounting. Within the electric igniter mounting, flexible cables may be present, which may enable a traversing of the ignition tip due to the flexibility. These flexible cables that may be present within the electric igniter mounting may however be surrounded by a housing (of the electric igniter mounting), and thus may not be accessible and visible from the outside. Thus, a simple handling of the device may be enabled, and loose wires may not collide and/or touch other components or a user.

According to an embodiment of the present invention, the traversing device may have a, in particular sleeve-shaped (or ferrule-shaped), guide or guidance member having a guide opening defined by parallel internal walls, through which at least a part of the electric igniter mounting and/or at least a part of the electric igniter may be passed through, wherein in particular an outer surface of a part of the electric igniter mounting and/or a part of the electric igniter may slide along on the parallel internal walls of the guide during the traversing of the electric igniter. The guide may ensure that the movement of the ignition tip may be effected along the rectilinear traverse distance. In particular, the ignition tip may be lowered along the traverse distance described by the guide into the container and be moved upwardly from the latter. Thus, a collision with e.g. parts of the container and/or parts of walls of the container and/or parts of a lid may be avoided. The internal walls and/or the guide opening may have e.g. substantially cylindrical symmetry or also a cylinder shape. Thus, e.g. a cylinder-shaped electric igniter mounting may be guided reliably in a simple manner. Also, other geometric shapes of the internal walls and/or of the guide opening may be conceivable.

According to an embodiment of the present invention, the device may further have a gas supply device having a gas supply line having a gas outlet opening, wherein the gas supply line may be attachable section-wise offset parallel to a longitudinal direction (e.g. of a shaft/sleeve) of the electric igniter, preferably reversibly, (in particular at the electric igniter mounting and/or at a part of the electric igniter), wherein the attached gas supply line may be synchronously traversed together during a traversing of the ignition tip of the electric igniter by the traversing device, wherein the traversing device may be in particular configured to traverse the gas outlet opening to a (e.g. specifically for the gas ignition) defined position within the container.

The gas supply device may be provided for a gas ignition of the sample to be investigated. The gas supply device may be an optional feature, i.e. not contained in all embodiments according to the invention. The gas supply device may be attachable at, and releasable from, e.g. the electric igniter mounting. Thus, also flashpoint determination tests may be supported, which may require a gas ignition. The gas ignition device may not have a traversing device that is provided (additionally) specifically or exclusively for the gas supply device, but may be traversed by the (same) traversing device, by which also the electric igniter may be traversed (in particular along the rectilinear traverse distance). Thus, the device may be extended also for a gas ignition, without requiring additional traversing components. The traversing distance of the gas outlet opening may be parallel to (or in particular substantially colinear with) the traverse distance of the electric igniter and/or the ignition tip of the electric igniter. The position of the gas outlet opening that may be defined for the gas ignition may be the same or different from the position of the ignition tip that may be defined for the electric ignition. Thus, different standards or norms of flashpoint determination tests may be supported.

According to an embodiment of the present invention, the gas outlet opening of the gas supply line may be arranged underneath the ignition tip of the electric igniter, in particular underneath along the longitudinal direction of the electric igniter, such that a gas that may exit from the gas outlet opening is flammable by operating the electric igniter.

According to an embodiment of the present invention, the gas supply line may have a bend (or flexure) formed such that the gas outlet opening may be arranged underneath the ignition tip of the electric igniter, in particular underneath along the longitudinal direction of the electric igniter, and such that a gas that may exit from the gas outlet opening is flammable by operating the electric igniter. Thus, the electric igniter may be used for igniting the gas that may exit from the gas outlet opening, which gas may be used in turn, during a flashpoint determination test, for igniting the sample arranged within the container. Herein, the electric igniter may not need to be removed (from the traversing device and/or the electric igniter mounting), but may remain unchanged in its position. In particular, the gas supply device may be configured in order to be able to be used as an ignition in a flashpoint determination test, without changing the electric igniter in its position or orientation. Thus, a handling of the device may be simplified, in particular a (time) expensive and/or complicated rebuilding of the device for enabling a gas ignition, may be avoided. Thereby, e.g. a flashpoint determination test or plural flashpoint determination tests, which may require on the one hand an electric ignition, and on the other hand a gas ignition, may be performed in a shorter time. The gas supply line may have straight sections above and below the bend.

According to an embodiment of the present invention, for a, preferably reversible, mounting of the gas supply line, a gas supply line mounting may be provided, which may have a, in particular cylindrical, passage opening, through which the gas supply line may be guided and fixable, in particular by a screw, and which may further have fixation means, in particular a clamp and/or a clip, which may be configured to fix the gas supply device at least partially to a part of the electric igniter and/or a part of the electric igniter mounting, in particular elastically and/or by a screw and/or magnetically. Thus, a reversible fixation of the gas supply line may be achieved. The gas supply line mounting may be attached e.g. in an e.g. cylindrical indentation or a ring-shaped indentation at the electric igniter mounting, in particular by a form-fit and/or a frictional connection (or closed linkage). Thus, the gas supply line may be attached or removed in a simple manner, if required. A vertically defined positioning of the gas supply line (and/or in particular of the gas outlet opening at the end of the gas supply line) may be defined or given in particular due to the positioning of the ring-shaped indentation at the electric igniter mounting. An elastic mounting may simplify a handling, while a mounting with an (additional) screw may ensure a reliable and firm mounting.

According to an embodiment of the present invention, the passage opening, within which the gas supply line may be fixed, may be provided at a bent end of a retaining arm that may extend substantially vertical and that may be mounted, in particular vertically adjustable, at the fixation means.

The gas supply line may extend rectilinearly through the passage opening. Due to the bending of the retaining arm, the gas outlet opening of the gas supply line may be arranged underneath the ignition tip of the electric igniter, in particular underneath along the longitudinal direction of the electric igniter, so that a gas that may exit from the gas outlet opening may be flammable by operating the electric igniter.

According to an embodiment of the present invention, a pin may furthermore be provided, which may be pluggable through a passage opening of the clamp (or clip) of the gas supply line mounting and a hole of the electric igniter and/or of the electric igniter mounting in order to achieve a defined vertical positioning of the gas outlet opening relative to the ignition tip. Instead of a pin, a simple protrusion on an inner surface of the clamp may be provided (e.g. integrated), which protrusion may engage, in particular may snap-fit, into a hole (or a depression) of an outer surface of the electric igniter mounting. Thus, a precise positioning of the gas outlet opening within the container may be achieved.

According to an embodiment of the present invention, furthermore, a magnet may be provided, to which a magnetic attractive force may be applied by a magnet or a magnetizable material fixed to a part of the electric igniter and/or the electric igniter mounting in order to achieve a defined vertical positioning of the gas outlet opening relative to the ignition tip.

According to an embodiment of the present invention, the transfer device may be configured to traverse the electric igniter (and/or the electric igniter mounting) downwardly selectively by a first transfer distance or a second transfer distance as a function of a desired type of ignition (e.g. electric ignition or gas ignition), in order to move either the ignition tip of the electric igniter (in the case of selected electric ignition) or in the case of a mounted gas supply line (and selected gas ignition) the gas outlet opening to the respectively defined position (e.g. within the container). For transferring the gas outlet opening to the defined position (for gas ignition), the transfer distance may be shorter than the transfer distance which is conceived by the ignition tip in the case of electric ignition. The gas outlet opening may thus be positioned underneath the ignition tip in order to advantageously be able to ignite a gas that may exit from the gas outlet opening, if needed, by the operated ignition tip of the electric igniter.

According to an embodiment of the present invention, the electric igniter may be configured as a glow plug (e.g. for the automotive area, e.g. for pre-glowing a diesel motor), in particular as a metal or ceramic glow plug. Thus, the electric igniter may be available conventionally, which thus may lower the costs of the device.

According to an embodiment of the present invention, the ignition tip may have a sleeve (e.g. a cylindrical sleeve), which may be manufactured of metal and/or ceramics, which may be closed (which e.g. forms the sheathing) at the front end, in the hollow space in a front region of which a coiled glow filament may be arranged. The coiled glow filament may heat the whole ignition tip to a temperature required for the ignition of the sample. In order to ensure a quick heating, the voltage applied to the electric igniter may be regulated.

The hollow space of the sleeve may be evacuated, or be filled with a suitable medium, for example gas or sand.

According to an embodiment of the present invention, the electric igniter may further have, in the hollow space in a rear (or middle) region, a coiled regulation filament, in particular having a resistance that may rise with the temperature, which filament may be electrically connected to the coiled glow filament. Thereby, a quick heating may be achieved, if a constant voltage is applied, wherein the heating power may decrease with rising temperature for a constant voltage, in order to thus reach a target value of a temperature of the ignition tip slowly. Such coiled glow filaments and coiled regulation filaments may be present in conventionally available glow plugs.

According to an embodiment of the present invention, the device may further have a driver module, which may be configured and connected to apply a direct voltage (or d.c. voltage) between ends of the wire of the electric igniter, in order to guide an electric direct current (or d.c. current), in particular between 5 Ampere and 15 Ampere, through the coiled glow filament. Thus, no high voltage supply may need to be provided in order to achieve an ignition by the electric igniter. Furthermore, no pulsed operation may be required, the direct voltage may remain uninterruptedly and/or for a desired electric ignition be applied continuously (in any case during a desired ignition time period). Thus, the device may be further simplified with respect to conventionally used devices.

According to an embodiment of the present invention, a flashpoint determination system (which may be configured e.g. also for the determination of the combustion point) may be provided, which may have: a container for receiving a (liquid and/or gaseous) sample to be investigated; in particular an (optional) lid for closing the container (in particular at an upper side), wherein the lid may have a closable lid opening; a heating device for heating the sample with a heating rate and/or to a defined temperature; and a device for igniting the sample arranged in the container according to any one of the embodiments described precedingly.

If a lid is present, the device for igniting may be arranged such that upon a transferring of the ignition tip of the electric igniter to the defined position within the container the ignition tip may be guided through the lid opening.

The container may be, e.g. substantially, cylindrical. The sample may, in the liquid state, fill e.g. about ⅓ to ⅔ of the inner space of the container. Above the liquid level of the sample within the container, the sample may be present in the gaseous state, in particular mixed with air.

Not all embodiments of the flashpoint determination system may have a lid, because some flashpoint determination tests may be performed with an open container. The lid of the container may thus be optional. The closable lid opening may enable the insertion of an igniter, in particular the electric igniter, and also of the gas outlet opening of the (optional) gas supply line, so that the flashpoint determination system can be configured for igniting by electric ignition and for igniting by gas ignition. During a flashpoint determination test, the sample within the container may be heated up (or cooled down) to a particular temperature by the heating device (e.g. an electric heating device or a combustion heating device) (or more generally a temperature-control device for heating and for cooling), whereupon the (initially closed) lid opening may be opened (e.g. by a pusher) in order to move either the ignition tip of the electric igniter or the gas outlet opening of the gas supply line to the respectively defined position within the container. Thereupon, the electric igniter may be operated, in order to either act itself as the igniter, or in order to ignite a gas that may exit from the gas outlet opening, by which gas the sample may be ignited. Whether an ignition of the sample is effected, may be determined by one or more detectors, which may be guided into the container through other entry openings within the lid, or which reach into the open container without traversing through the lid. If the presence of the flashpoint could not be detected, then the sample may also be brought to another (e.g. higher) temperature, whereupon a further ignition test may be effected.

It should be understood that features, which have been discussed or are provided individually or in any combination, in connection with a device for igniting a sample arranged in a container for a flashpoint determination test, are also applicable individually or in any combination for a method of an igniting of a sample arranged in a container during a flashpoint determination test, and vice versa, according to embodiments of the present invention.

According to an embodiment of the present invention, there is provided a method of an igniting of a sample arranged in a container during a flashpoint determination test and/or a combustion point determination test, the method having: traversing an ignition tip of an electric igniter, or a gas outlet opening of a gas supply line coupled to the electric igniter, to a defined position within the container, wherein the electric igniter has an ignition tip having an encapsulated electric wire.

Embodiments of the present invention support all flashpoint determination techniques that are known at the application date, also those, which require an open container and which require e.g. also a horizontal movement of the igniter. To this end, the traversing device may also be configured to move the ignition tip in a horizontal direction, in particular to laterally different positions within the container.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

Elements, which are same or similar in function and/or structure are referred to in different figures by reference numerals, which differ only in the first digit. A description of an element, which is not explained in detail in a particular embodiment, can be taken from a corresponding description of this element in another embodiment.

The flashpoint determination system100according to an embodiment of the present invention, which is illustrated in theFIGS.1A and1Bin two different traversing states, may have a container101for receiving a sample to be investigated, which sample may have a liquid portion103and a gaseous portion (and/or sample-gas-air-mixture)105. The flashpoint determination system100may further have a lid107for closing the container101at an upper side, wherein the lid may have a closable lid opening109. In the illustrated embodiment, the lid opening109may be closable and openable by a pusher111, for which purpose the pusher111may be shifted e.g. along the directions indicated by the arrow113.

FIG.1Aillustrates the state, in which the lid is closed by the pusher111, whereasFIG.1Billustrates the state, in which the pusher111is pushed back, such that the lid opening109may be open and the inside of the container101may be in contact with the surroundings.

The flashpoint determination system100may further have a heating device115, which may be configured for heating the sample103,105within the container to a particular temperature. For measuring the temperature, the flashpoint determination system100may have optional measurement sensing elements117, which may be configured e.g. for measuring the temperature within the liquid phase103. The measurement sensing elements117may be inserted into the interior of the container101through a further opening in the lid107, for which purpose a rod119may be conceived.

Optionally, the flashpoint determination system100also may have a stirrer121, which may have a stirring rod123, which may be guided through the lid107and which may be supported rotatably around a substantially vertical direction125. Stirring paddles127may be fixed at the lower end of the stirring rod123within the container101. The sample103,105may be stirred, e.g. during a flashpoint determination test, by the stirrer121. The stirrer121may be optional, thus not necessarily present in all embodiments.

The flashpoint determination system100further may have a device129for igniting the sample103,105arranged in the container101, according to an embodiment of the present invention. The device129for stirring the sample103,105arranged in the container101may have an electric igniter131, which may have an ignition tip133having an encapsulated electric wire (not illustrated in theFIGS.1A and1B). The electric wire may have e.g. a coiled glow filament435and a coiled regulation filament437, as is illustrated inFIG.4in a longitudinal cross-sectional view as an example of an electric igniter431according to an embodiment of the present invention. The electric igniter131inFIG.1may be composed like the electric igniter431illustrated inFIG.4.

The wire435,437of the electric igniter131,431illustrated inFIG.4may be encapsulated and/or sheathed liquid-tightly and gas-tightly by a sheathing441, which may comprise e.g. a sintered ceramic. The sheathing may have a cylindrical shape in the region of the ignition tip433, within which the coiled glow filament435may be arranged. The sheathing may continue also in the igniter shaft134,434, in which the coiled regulation filament437may be located.

The device129for igniting may further have a transferring device (or moving device)139, which may be configured for traversing (or moving) the ignition tip133of the electric igniter131to a defined (for an electric ignition) position ze, e.g. defined by a vertical distance from a bottom102of the container101or by a vertical distance from the lid107. A gas outlet opening of a gas supply line that is described further below may be traversed e.g. to a position zg, which may be the same as or different from ze.

The traversing device139may be configured to traverse the ignition tip133of the electric igniter131upwardly and downwardly along a rectilinear traverse distance143. In the illustrated embodiment, the traverse distance (or moving distance)143may enclose an acute angle α (e.g. between 5° and 40°) to the vertical direction125.

The traversing device may have an electric motor145having a motor shaft147, at which an eccentrically arranged shaft149may be mounted via a connection piece151. The eccentrically arranged shaft149may engage in an oval opening153of a further connection piece155, which may be connected to an electric igniter mounting157. The connection piece151, the eccentrical shaft149, the oval opening153, and the further connection piece155may form a crank drive150, which may be configured to transform a rotational movement of the electric motor145in a translational movement, i.e. a rectilinear movement. For e.g. a rotation of the motor shaft147around less than 90°, the ignition tip133may thus be traversed along the rectilinear traverse distance143from the position (e.g. parking position) illustrated inFIG.1Ato a defined position (vertical position ze), which may be conceived in a flashpoint determination test, as is illustrated inFIG.1B. The ignition tip133inFIG.1Bmay be located underneath the lid107and within the container101.

The electric igniter mounting157may be conceived in order to support the electric igniter131, wherein the electric igniter131may be connectable in particular by a screw-fastening to the electric igniter mounting157and is illustrated connected in theFIGS.1A and1B.

The traversing device139may further have a guide or guidance159having an opening or guidance opening161, which may be defined by internal walls165, through which at least a part of the electric igniter mounting157may be passed through. Therein, parts of an outer surface163of the electric igniter mounting157may slide along at parallel internal walls165of the guide159, which walls may define the guidance opening161.

The flashpoint determination system100may further have a driver module167, which may be configured and connected to the electric igniter131(via non-illustrated electric cables), in order to apply a direct voltage between two ends of the wire (e.g.435,437) of the electric igniter131, in order to guide an electric direct current in particular through the coiled glow filament (e.g.435inFIG.4).

FIG.2illustrates, in a schematic perspective representation, a part of a flashpoint determination system200according to a further embodiment of the present invention.FIG.2illustrates the state, in which a covered (or concealed) ignition tip233of the electric igniter231is positioned at a defined position within the container201.

The electric igniter231of the flashpoint determination system200may have an ignition tip233, which may be guided through the lid opening209of the lid207, and which may be partially concealed by the lid207, and which may be delimited to the outside by a ceramic sheathing, and in the interior of which a coiled glow filament may be arranged, such as it is indicated e.g. inFIG.4by the reference numeral435. In the upward direction, there may be attached an igniter shaft234, which may have a somewhat greater diameter, in the interior of which shaft the coiled regulation filament (e.g.437) may be arranged. Further upwardly, there may connect a fixation section285, which may have e.g. an outer thread for the fixation to the electric igniter mounting257. The electric igniter mounting may have substantially a cylindrical symmetry and may have substantially a cylindrical shape.

The electric igniter mounting257may have a coupling section258, which may have e.g. an inner thread, into which the glow plug and/or more generally the electric igniter231may be screwed in. Furthermore, the electric igniter mounting257may have a fixation section261of a gas line mounting, which section may be formed by a ring-shaped peripheral indentation in the outer surface of the electric igniter mounting257, and which may be clampable by a clamp of a gas line mounting for a gas supply device, as can be seen e.g. inFIG.3.

FIG.3illustrates, in a schematic perspective representation, a flashpoint determination system300according to a further embodiment of the present invention, wherein similarities to the flashpoint determination system illustrated inFIG.2are present. InFIG.3, there is illustrated a state of an ignition tip that is not arranged within the container301, e.g. while the sample is brought to a particular temperature with a closed lid307.

In contrast to the embodiment illustrated in theFIGS.1A,1B and2, the device329for igniting the sample arranged in the container301may further have a gas supply device370having a gas supply line371having a gas outlet opening373(at one end of the gas supply line371), wherein the gas supply line371may be reversibly mountable section-wise parallel offset to a longitudinal direction375(parallel to the traverse path143, seeFIG.1) of the electric igniter331to the electric igniter mounting357, and in particular in the fixation section361of the gas line mounting. The gas supply line371may have straight sections adjacent to a bend372, one of which may lead to the gas outlet opening373. By the bend372, the gas outlet opening373may be located underneath the ignition tip333.

In the right-hand part ofFIG.3, the gas supply device370is taken away, i.e. separated from the device129and/or329for igniting, and in particular separated from the electric igniter mounting357, while on the left-hand side ofFIG.3, the gas supply device370is mounted to the electric igniter mounting357by a clamp377. The clamp377may be part of a gas line mounting379, which may have a cylindrical passage opening381, through which the gas supply line371may be guided and may be fixable, in particular by a clamping screw383. The gas line mounting379may further have the clamp377, which may be configured to clamp around at least partially a part361of the electric igniter mounting357elastically or by a screw. Furthermore, a pin may be provided, which may be guided through a non-illustrated opening within the clamp and into a hole in the electric igniter mounting357, in order to enable a defined vertical positioning of the gas supply device370, in particular of the gas outlet opening373relative to the ignition tip333.

The electric igniter431that is illustrated inFIG.4in a schematic longitudinal cross-sectional view may be configured as a glow plug, which may have in its front end as an ignition tip433a closed sheathing (or ferrule)441, in the hollow space of which there is arranged a coiled glow filament435. The electric igniter431may have, in a fixation section485, an outer thread487, by the help of which the electric igniter431may be supported by the electric igniter mounting (e.g.157,257,357in theFIGS.1to3) and/or may be screw-fastened. A connection section489may enable an electric connection of the wire, in particular the coiled glow filament435and the coiled regulation filament437, with e.g. an exterior circuit, e.g. the driver module167, which is illustrated in theFIGS.1A and1B. The interior space and thus also the coiled glow filament435and the coiled regulation filament437may be sealed gas-tightly and liquid-tightly against the outer space by the sheathing441. For this purpose, one or more seals may be provided within the electric igniter.

The electric igniter may be formed as a glow plug known from the automotive sector, such as it is used e.g. in diesel engines for pre-glowing. The encapsulation (e.g. the sheathing441) may protect sensitive parts against a mechanical damage. The operation of the electric igniter illustrated inFIG.1may be effected with a direct voltage and without a high voltage generator. A difference of a glow plug to a conventionally used glow filament for flashpoint determination tests may be e.g. the encapsulation. Thus, the size of the outer surface and the constitution (or quality) of the outer surface may be significantly different. The glow plug used according to an embodiment of the present invention may require a mode of operation that is different from a conventionally used electric igniter. For example, a pulsating high voltage of ca. 1 kV may be required for a spark-generating ignition plug, whereas the glow plug may not need to be pulsed and an operation may be effected with usual power supply voltage (or line voltage). According to an embodiment of the present invention, a voltage of e.g. between 5 V and 10 V, in particular between 7.5 V and 8.5 V, may be applied to the ends of the wire of the electric igniter, in order to bring the glow plug to be glowing. The material of the tip may be ceramic, the shape of the tip may be rod-shaped and may comprise a homogeneous material. The temperature of the tip may amount e.g. to between 1000° C. and 1500° C. during an ignition operation.

FIGS.5and6illustrate gas supply devices570and/or670according to further embodiments of the present invention, which may be conceived e.g. for the device129or329instead of the gas supply device370.

In contrast to the gas supply device370illustrated inFIG.3, the gas supply devices570and/or670each may have a retaining arm591and/or691, which may extend substantially vertical (and in particular parallel to the electric igniter, if mounted to the electric igniter), which may be attached in an upper section to the fixation means, in particular the clamp577and/or677, and which may have at a lower end a bent region or bending (from the vertical525and/or625)593and/or693the passage openings581and/or681, through which the gas supply line571and/or671may be guided and may be fixed therein. Due to the bending593and/or693, the gas supply line may be formed to extend rectilinearly.

While the retaining arm591illustrated inFIG.5may be mounted fixedly to the clamp577, the retaining arm691illustrated inFIG.6may be slidable in the vertical direction625relative to the clamp677. To this end, a sheathing692(having a rectangular cross-section) may be mounted to the clamp677, into which sheathing the retaining arm (having a rectangular cross-section) may be inserted and may be slidable therein, in order to enable adjusting the (vertical) position of the gas outlet opening673, in particular positioning it underneath the ignition tip of the electric igniter. If the correct position is adjusted, the retaining arm may be secured by a clamping screw695.

The electric igniter may be used for igniting a liquid-gas-mixture of a sample to be investigated (in the case of a desired electric ignition) as well as for igniting a gas, which in turn may be used for igniting the liquid-gas-mixture of the sample to be investigated (during a gas ignition). The electric igniter, in particular the glow plug, may be screw-fastened in a mechanical mounting (e.g. electric igniter mounting157,257,357). An encapsulated plug for voltage supply may be built in the housing of the device, such that open cables that may be accessible for a user may be avoided. The gas line mounting379may also be referred to as an adapter, which may allow to clamp a gas supply line to the mounting of the glow plug, e.g. by a clamp. By a pin arranged in the adapter, the gas supply line and/or in particular a gas outlet opening may be correctly positioned at the bore that may be provided for this purpose in the electric igniter mounting. Prior to and during the measurement, the igniting of the gas by the electric igniter may ensure that a gas flame is present for each immersion process. The immersion depth of the electric igniter mounting including the gas ignition adapter may be adapted electronically such that the igniting of the samples may be guaranteed by the gas flame and not by the hot ignition tip of the electric igniter.

In contrast to conventional methods, the electric igniter may be moved linearly and/or rectilinearly into the crucible (i.e. the tip is moved downwardly from the upside into the crucible without tilt of the igniter). By the rectilinear operation, in particular the rectilinear and/or translational traversing movement of the electric igniter, a manual changeover of the ignition types may be facilitated. According to an embodiment of the present invention, the electric igniter may remain incorporated and fixed fixedly in the electric igniter mounting, also when the gas supply device and/or the gas supply line may be mounted to the electric igniter mounting (in particular by a clamp). The correct immersion depth of the respective ignition source may be adapted and controlled electronically by the selection of the ignition type.

The use of an encapsulated electric igniter, in particular a glow plug, may have different advantages: By encapsulating the heated coiled filament, the size of the surface and the quality (or nature) of the glow plug may be significantly more advantageous for the operation as an electric igniter than the conventional open metallic wire spiral. Possible significant improvement of the stability and resistance against mechanical load, e.g. in the case of a rough touching by other objects or a falling to the ground during a changeover the ignition type. The conventionally used open (unprotected) spiral may be deformed completely as result of a mechanical shock, and thus may become unusable.

An operation with direct and/or alternating voltage may enabled, wherein no high voltage generator is necessary. A mechanical stability of the immersion mechanism during operation as an igniter may be ensured, because the glow plug may be inserted into the crucible by the rectilinear movement without rotation. A significantly improved operation safety may be achieved by placing the cables in an area of the interior of the housing that may not be accessible for the user. A significant facilitation (or ease) of the changeover of the desired ignition type may be achieved, wherein no exchange of the electric igniter to a gas igniter may be required. Instead, the gas igniter may be mountable to the mounting of the glow plug via an adapter.