This application is a U.S. National Phase Application of PCT International Application No. PCT/SE2012/051193, filed on Nov. 1, 2012, designating the United States of America and published in the English language, which is an International Application of and claims the benefit of priority to Swedish Patent Application No. 1151039-3, filed on Nov. 4, 2011. The disclosures of the above-referenced applications are hereby expressly incorporated by reference in their entireties.
The present invention relates to a method of internally distributing Hg in a fluorescent tube body in a vertical pumping device in accordance with claim 1 and the vertical pumping device per se according to the introductory portion of claim 8.
The invention concerns the manufacturing industry for the manufacture of fluorescent tubes, where a purification process for the interior of the fluorescent tube body takes place in a so-called vertically operating pumping process. The purification takes place before a final amount of lamp gas intended for the operation of the fluorescent tube is filled in the fluorescent tube body.
The purification process (the pumping process) brought about by the vertical pumping device comprises a vacuum system (underpressure system) which creates an underpressure in the fluorescent tube body and a targeted particle flow with particles to be removed from the fluorescent tube body. This particle flow in the fluorescent tube body stops when degassing of substances has ceased. Sometimes, the particle flow may even reverse.
In order to solve this problem, a technique has been developed which supplies substances creating a new particle flow. This technique employs liquid mercury, which is applied in the interior of the fluorescent tube body at the lower part of the fluorescent tube body. The mercury gasifies with great expansion. The gasified mercury also has the ability to bind contaminants. At the expansion, the mercury thus binds the contaminants and conveys them out of the fluorescent tube body in the additional particle flow obtained. The liquid mercury, provided in order to create the additional particle flow, is dosed at the pumping process in a first position where gasification has ceased and pumping out of particles is most desirable. The dosing is done by flow throttling. When the lamp then reaches the end of the vertical pumping device with ensuing final filling of the lamp gas, an additional amount of mercury will be dosed into the fluorescent tube body to provide the lamp gas for the operation of the fluorescent tube. Earlier on, vertical pumping devices were thus filled with liquid mercury, which worked production-technically, but which at the same time entailed a ten percent loss of mercury.
The document JP 2000208050 shows a device for distributing bound mercury in pellet form. An electromagnet is arranged to lift a valve when the intended pellets are supplied. The aim with the device is to prevent involuntary supply of pellets into the fluorescent tube body because of device vibrations.
The need remains to be able to devise the above method and pumping process more environmentally friendly than what has hitherto been achieved. Traditional vertical pumping devices work satisfactorily, but are now being subject to further developments.
Hence, it is the object of the invention to devise a pumping process where the environmental adaptation is greater simultaneously with an excellent purification of the fluorescent tube body being achieved.
Likewise, it is the object to achieve a cost-effective distribution of mercury for the pumping process, whereby the consumption of mercury can be minimized.
It is also the object is to devise a vertical pumping device which operationally reliably can distribute mercury in a fluorescent tube body, where the fewest possible movable parts are acting in the vertical pumping device during the pumping process.
The above objects have been obtained by the method defined in the preamble according to the steps set forth in claim 1.
In this way a method has been achieved, which allows an exact distribution of mercury partly for the purification and pumping process, and partly the final dosing per se of mercury. This exact distribution for both purification and final filling entails that no superfluous mercury is generated in the process, which spares the environment. The exact dosing also brings about cost savings in the production. The environment of the service staff likewise gets better by way of a controlled amount of supplied mercury in solid form for the entire vertical pumping process, both as regards pumping/purification of the fluorescent tube body and final filling of mercury for the production of the lamp gas.
Preferably a step is effected of coupling the upper end of the fluorescent tube body to an evacuation pump to bring about an underpressure in the fluorescent tube body before the step of arranging, in the first position, the first solid body.
The method thereby allows automated operation for vertical pumping where the fluorescent tube body is retained to the vertical pumping device directly by connecting the fluorescent tube body to the vertical pumping device, and an underpressure can be applied rapidly in the interior of the fluorescent tube body immediately after arranging the first and the second position with respective first and second amounts of bound mercury. In this way an effective cost-saving pumping can be achieved.
In the first position, the first solid body is expediently dropped manually to the bottom before a valve unit is applied connecting to the fluorescent tube body, the valve unit being arranged in such a manner as to be openable by magnetic force so that, in the second position, the second solid body can drop down into the fluorescent tube body by gravity.
In this way the vertical pumping device can be made less voluminous, as the first solid body can be dropped down (arranged) into the fluorescent tube body before the valve unit is applied connecting to the upper part of the fluorescent tube body. The valve unit can be made less voluminous as just one solid body needs to be arranged after the said connection has been made.
Alternatively, a valve unit is arranged in such a manner as to be openable by magnetic force so that, in the first position, the first solid body can drop down by gravity to the bottom of the fluorescent tube body and that, in the second position, the second solid body can drop down into the fluorescent tube body by gravity.
Thereby, the valve can easily be controlled to open and close partly for arranging the bodies in the valve, partly for dropping down each of the bodies separately into the fluorescent tube body at chosen times. The control can be effected with few movable parts and without through-going parts which could affect the created underpressure required for the release of mercury through the gasification.
Preferably, a distribution valve is arranged with a first valve element delimiting an upper and a lower chamber of the distribution valve and a second valve element delimiting the lower chamber and the fluorescent tube body, the method comprising the step of placing, after the distribution valve has been applied connecting to the fluorescent tube body, the first and the second solid body in the lower and the upper chamber, respectively.
In this way the first body may be arranged in a lower position, which is first given the opportunity to open for dropping down from the lower chamber, and the second body can be given the opportunity to drop down to the lower chamber so as to be able to drop down from there, in a later position, into the fluorescent tube body when the valve is made to open towards the fluorescent tube body.
The step of releasing the fluorescent tube body from the vertical pumping device is expediently preceded by a step of closing the other upward facing end of the fluorescent tube body.
Thereby, the fluorescent tube can be closed with lamp gas already when it is to leave the vertical pumping device, which is cost-effective.
Alternatively, the method comprises achieving the solid bodies with bound Hg by cutting of bar blanks of bound mercury in solid form to predetermined lengths and subsequent conveyance of these cut bodies to the vertical pumping device, whereby a cost-effective production of fluorescent tubes can take place.
The above objects also have been obtained by the vertical pumping device defined in the preamble according to the characterizing portion of claim 8. In this way a vertical pumping device is accomplished, which allows exact distribution of mercury partly for the purification and pumping process, partly the final dosing per se of mercury. This exact distribution for both purification and final filling entails that no superfluous mercury is generated in the process, which spares the environment. The exact dosing also brings about cost-savings in the production. The environment of the service staff likewise gets better by way of controlled amount of bound mercury in solid form for the entire vertical pumping process, both for pumping/purification of the fluorescent tube body and for final filling of mercury for the production of the lamp gas.
Preferably, a distribution valve arranged at each support position is to take up the first and the second solid body and, in separate process positions, feed them further on to the respective fluorescent tube body, each distribution valve comprising a first and a second valve element, each of which is separately influenceable by magnet units fixedly arranged in predetermined process positions of the vertical pumping device to arrange the first and the second body in a first and a second position, respectively.
In this way an automatic device may be obtained cost-efficiently for exact distribution of both the first body and the second body.
A distribution valve arranged at each support position is expediently designed with a first valve element delimiting an upper and a lower chamber, and a second valve element, in operation delimiting the lower chamber from the fluorescent tube body, the first valve element being arranged so as to be influenceable by magnet units while the second valve unit remains in closed position, and where the second valve element is arranged so as to be influenceable by magnet units while the first valve unit remains in closed position.
The first body can thereby be arranged in the lower position and be given the opportunity, by opening of the second valve element, to be dropped down into the fluorescent tube body, and release of mercury takes place.
The second body can be given the opportunity to drop down into the lower chamber from the upper chamber in order, in a later position, to be able to drop down from the lower chamber into the fluorescent tube body when the valve is made to open towards the fluorescent tube body. Thereby, the valve can easily be controlled to open and close, partly for arranging the bodies in the valve, partly for dropping down each of the bodies separately into the fluorescent tube body at chosen times for release of an exact amount of mercury. The control can be effected with few movable parts and without through-going parts which could affect the created underpressure required for the release of mercury through the gasification.
Alternatively, the magnet unit consists of a first electromagnet generating a first force, and of a second electromagnet generating a second force, the said electromagnets being placed in predetermined separate process positions.
An automated cost-efficient production has thereby been achieved.
Preferably, the first and the second electromagnets generate forces in opposite directions.
Thereby a compact vertical pumping device can be obtained, where the first electromagnet works to press down the first valve element, made from stainless steel, in the direction towards a spring force for opening of a gap through which the body can fall for arranging the second position, and the first electromagnet also works to press down the second valve element tightly (so that at least the solid body is prevented from falling through) against a shoulder between the lower chamber and the fluorescent tube body. The second electromagnet works, at the second release, to lift the second valve element so that the body can fall down into the fluorescent tube body simultaneously with the second electromagnet working to lift the first valve element against a shoulder, which the said spring force also makes the first valve element abut against when the support position is in another indexing position than in the position adjacent to or in line with the first electromagnet. In this way current can control the force and the velocity with which the valve is opened, depending on the application. The vertical pumping device may cooperate with a computer to control the valves without the underpressure being influenced by movable through-going parts.
Alternatively, the magnet unit may be a permanent magnet.
Preferably, the first and a second valve element of the distribution valve are formed by a partition wall arranged in a hollow cylindrical cylinder being rotatable about its axis of rotation, around which, and on substantially opposite sides, there are arranged storage spaces for first and second solid bodies, respectively.
Thereby, first and second solid bodies can be filled (arranged in an indexing position, which is time saving. When the first body is to be placed into the fluorescent tube body for the first release of mercury, the hollow spindle is rotated a quarter of a turn about its axis of rotation by means of a camming motion, and then, to close, a quarter of a turn back. When the second body is to be placed into the fluorescent tube body for the second release of mercury, the hollow spindle is rotated a quarter of a turn in the direction towards the previously made quarter of a turn by means of a second camming motion.
The first indexed process position allowing release of the first amount of Hg in the fluorescent tube body is expediently arranged with means in the form of heat. The first solid body can thus be dropped down manually to the bottom before a valve unit is applied connecting to the fluorescent tube body. The valve unit is arranged in such a manner as to be openable by magnetic force so that, in the second position, the second solid body which was loaded in the valve unit can drop down into the fluorescent tube body by gravity. In this way the vertical pumping device can be made less voluminous as the first solid body can be dropped down (arranged) in the fluorescent tube body before the valve unit is applied connecting to the upper part of the fluorescent tube body. The valve unit can be made less voluminous because just one solid body (the second solid body) needs to be arranged after this connection has been made.
Preferably, a unit is provided for arranging, in a third position, at least one third solid body comprising a predetermined third amount of bound Hg so as to be able to bring about a third release of the third amount of Hg in the fluorescent tube body through gasification.
Thereby, complementary gasification can be achieved with an exact amount of mercury.
The invention will now be explained with reference to the drawing, which schematically shows:
a-6g the mode of operation of a distribution valve of the vertical pumping device in
a-7c a means arranged for allowing the release of mercury in exact predetermined first and second amounts, respectively, in a sixth embodiment; and
The invention will now be explained by means of embodiments. Details in the schematic drawings may occur representing the same type of detail, but in different figures with the same reference numeral. The drawings are not to be interpreted strictly, and details that are not important to the invention have been left out therefrom for the sake of clarity.
In position h, the fluorescent tube body 3 is conveyed to the next indexed process position for filling of lamp gas, where the valve ball 15″ is in its closed position. In position i, the spring-loaded valve 15′ is once again influenced by a third electromagnet 19′″ arranged in this indexed process position and pressed down to allow arranging of the second solid body 9″ in the lower chamber 17″ so that, in the next position j, an additional fourth electromagnet 19″″ lifts the valve ball 15″ to allow the second solid body 9″ to fall down into the fluorescent tube body 3 by gravity for production of the exact amount of lamp gas with the exact amount of mercury through a second release E2 of mercury.
a-6h show schematically the mode of operation of the distribution valve 13″″ of the vertical pumping device 1 in
a-7c show schematically a means in the form of a membrane valve 13′″″ arranged to allow the release of mercury in exact, predetermined first and second amounts according to a further embodiment. In
The invention should not be considered to be limited by the embodiments described above, and there are also other embodiments within the scope of the invention which likewise describe the gist of the invention or combinations of the described embodiments. Other substances can of course be bound with mercury, such as tin, zinc, copper, silver, gold, titanium etc. Also other types of distribution valves can be used for the above-mentioned release. Other positions for arranging further solid bodies with bound Hg could also be of interest, depending on the desired degree of pumping in the process. For example, mercury may be arranged in the vertical pumping device in four process positions for further pumping and final filling of the fluorescent tube body to obtain improved service-life of the fluorescent tube simultaneously with sparing the environment through the exact, predetermined desired amount of Hg released according to the invention in all of the four process positions. The important thing is that the inventors of the present invention solve the problem of Hg environmental impact and the problem of high production costs by applying Hg in an exact amount in the fluorescent tube body, both at the pumping and when generating lamp gas. Different types of spring valves with pressure springs, tension springs, other elastic elements and valve bodies can be used for achieving a suitable valve unit for distribution of an exact amount of mercury.
Number | Date | Country | Kind |
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1151039-3 | Nov 2011 | SE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/SE2012/051193 | 11/1/2012 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2013/100842 | 7/4/2013 | WO | A |
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0 669 639 | Aug 1995 | EP |
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Entry |
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International Search Report for PCT/SE2012/051193 dated Feb. 15, 2013. |
Number | Date | Country | |
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20140287645 A1 | Sep 2014 | US |