Showing posts with label medium pressure. Show all posts
Showing posts with label medium pressure. Show all posts

Monday, 8 March 2021

The Neon Medium/High Pressure Arc-discharge Lamp

 

OPEN SOURCE EVERYTHING – QUESTION EVERYTHING


Q and A – A Discussion - Researchment, Questions and Expectations




Depiction of supposed ED28/ED90 HID Neon Lamps



Q - What is it intended to be, how to look like?
A - Consider it as the HID counterpart of the neon signs filled with neon, in the way as the Ar-Hg HID lamp is that counterpart of the neon-signs filled with Ar-Hg. 
Or, the HID version for neon, from the point of view of what means the HID mercury lamp.

Q - Was ever manufactured a similar lamp?
A - Not in a commercial form. But, as we know, long-time ago, there were some studies about, and some attempts to develop a compact HID neon lamp of this kind, with a higher lm/W red light, than so as were at that time the cold cathode neon beacon lights. But we do not have any papers from that time, nor would you find some satisfactory now.
 But you have instead a newer patent paper on this concern, that is really interesting. Here it is:

Q - Why do you think that development not continued?
A - Don't know anything more about, but supposedly problems with electrodes and arc tube erosion. Or, anything else.

Q - And now? Are there greater chances of success?
A - From a commercial perspective, not. You have now red LEDs, and you can achieve, if you want, ED28/ED90 (clear or diffusing) filament LEDs of red color, with even up to ten times more lm/W. (But for beacon red lights you need an amount of IR emission too, beside of the visible light output).

Q - Again the questions, as in previous cases.
 Do you consider a researchment of all components from scratch, or do you rather consider to put together components that are already 'on market'?
A - Again, as long as it is intended to be a lamp for limited purposes, the intention is to put together as possible what is already at disposal.

Q - So, what do you need to put together in order to achieve the desired lamp?
A - The same, all the main component parts of a HID mercury lamp; - arc-tube, frame, outer bulb, stem, screw-cap: http://lamptech.co.uk/Documents/M1%20Introduction.htm

Q - What about the arc-tube? What is the preferred range of power for the desired lamps?
A - Let consider it around 250W, at least for the research case. 

Q - No more or less, but only 250W?
A - Yes. Concerning the low lm/W of expected neon discharge, the 250W might be considered not too much, but also enough high for, let say a 15-20lm/W, for a reliable output.
However, the arc tube needs to be made of alumina silicate hard glass instead of quartz glass.

Q - So, what rate of success do you expect in development of the under discussion lamp, or do you expect a reliable success of the experiment?
A - Ask please rather, what problems do you expect or do you have to overcome (because there are, believe!), before to discuss about the success into achieving a lamp that is similar with the incandescent one in its lm/W output.

Q - Yes! Then, why the entire discussion about this experiment? Or, is it somehow also the case of the N2 and CO2 lamps, discussed in a previous post? 
Is it, let's say: - For the seek of the red light, and the idea itself, and also for the seek of research and portfolio of discharge lamps as a whole.
A - Hmm!... You guess it already...

Q - OK! but in that previous post you mean that: - You have now at disposal the dielectric barrier discharge lamp in a more advanced stage of development, so you can use it from start, in case of gases that are not 'noble'. But why do you not use it also for neon discharge, if there are or might be so big problems using a common HID lamp?
A - It leads very likely into excimer formation, so you get an excimer lamp, rather than a simple gas discharge lamp. And, yes! You have already neon excimer lamps, but as a source of far UV (VUV), not as one of red light.

Q - In earlier posts you speak about the neon-mercury HID lamp. Is this somehow a similar HID lamp as the well known mercury lamp, but filled with neon beside the mercury, instead of argon?
A - No! Or it might be only, but only, in its appearance, not as functionality. What we mean by the neon-mercury HID lamp is a lamp in which the main discharge remains in neon.
 - If you build a HID lamp with neon and mercury (similar to the mercury lamp with argon), after the warm up of the lamp, the mercury discharge will take over entirely the discharge process. It will simply keep out the neon gas to be longer involved in the discharge, instead keeping the neon only as a buffer gas. And this might be the case of 100 to 1, neon to mercury amounts, in pressure units of the hot lamp, or even more.

Q - And?!...
 A - Briefly, what have you to do is to rise up the difference, as much more neon and much less mercury, or to 'deplete' the mercury in the discharge process. And, in the case of medium or high pressure discharge,... anything but easy might it be...

Q - So, which one do you consider?
A - The first one, of course. The more, as long as you don't look to achieve a constant color or a constant lumen output.

Q - And, in what difference of neon and mercury pressure?
A - Again, only the research will answer, but,... as a speculation,... an 1000 to 1 would not be a surprise.

Q - In a previous post
you speak about a 'medium pressure neon-mercury discharge lamp', and that: It's main light spectrum is expected to come out from the discharge itself, and will be a reddish based spectrum. Let's say from light cyclamen to violet red, depending of the balance between neon and mercury (in discharge terms, not in 'weights').
How do you expect the spectrum depending on neon and mercury pressures? When cyclamen and when violet-red?
A - This is the desire, the goal of the experiment with neon-mercury HID lamp. In any way, it seems more easy for light cyclam, and more difficult for violet-red.

Q - Why so?
A - If you bring more blue and violet wavelength into the neon discharge, you will most likely get different nuances of cyclam or pink. It's about mixing wavelengths. In the plasma the wavelengths will 'mix'. But this is another subject. The violet-red will rather come out from the pure neon discharge with a violet glass, as a rough speculation. But with an efficiency that for sure will you consider inconvenient.

Q - Are the desired lamps expected to start directly, or would it be necessary a high voltage pulse.
A - Let's say, directly, at the supply voltage (of 220/230V) in case of internal starting electrode (and reactor ballast).



more content to come...





Saturday, 8 August 2020

The Fluorescent Medium Pressure Mercury Lamp


A source of large variety of light colors for esoteric use



Q and A - Researchment questions and expectations



Depiction of Medium Pressure Mercury Lamps
with Oversized Arc-tube and Outer Bulb
(lamps are shown as clear, for a better understanding)


Q - What is it intended to be, how to look like?
A - A medium pressure mercury lamp, in a form of a HID lamp, shaped as an ED/BT fluorescent coated bulb with an E33 or E(X)39/40 screw cap.

Q - Do you mean an E33 size of lamp screw cap, beside of the well known large ones?
A - Consider it as been in the way described here: http://lightcommunitylighting.blogspot.com/2018/01/e33-screw-caps-and-lampholders.html

Q - Was ever manufactured a similar lamp?
A - Yes, there is, and you find more details here: http://www.lamptech.co.uk/Spec%20Sheets/D%20MA%20GEC%20MAF400.htm
    But thus is it the closest to what in discussion here, it is similar to only a certain extent.

Q - Do you consider a researchment of all components from scratch, or do you rather consider to put together components that are already 'on market'?
A - As long as it is intended to be a lamp for limited purposes, for sure, the intention is to put together what is already at disposal.

Q - So, what do you need to put together in order to achieve the desired lamp?
A - For sure, all the main component parts of a HID mercury lamp; - arc-tube, frame, outer bulb, stem, screw-cap. http://lamptech.co.uk/Documents/M1%20Introduction.htm

Q - What about the arc-tube? What is the preferred range of power for the desired lamps?
A - We consider it from 75W to 400W.

Q - Do you somehow mean that some medium pressure UV lamps on the market, as there are, might be the arc tube, inside an ED/BT outer bulb, for your proposed lamp, at least in the research stage?
A - You are right.

Q - OK, but if we look for the medium pressure UV lamps, we find them as usual in the range of 1KW to even tens of KW, - isn't it?
A - Yes it is, but if you are in knowledge, you would say: Stop! You have missed the lamps used for photochemical reactors, that are as usual in the range of 125W, 250W, 400/450W, and even more,... and, the more, their UV spectrum has peaks at 254nm, 356nm and 365nm, and have also starting electrode.
-  As another example, you find also 400W medium pressure mercury UV lamps (arc tubes) which burn in any position (not only horizontal), which are 31mm arc length, 14mm dia, and burn at 3,5A, 125V arc voltage, and roughly the same UV spectrum, but have no starting electrode.

Q - Yes, but you speak about even lower power, as low as 75W. Are there somewhere medium pressure UV lamps of so a low power?
A - Yes, there are on the market some lamps for photochemical reactors, of 150W dimmable as low as 75W.

Q - What about the outer bulb? Is it intended to be the same used for high-pressure mercury lamp used for general lighting?
A - Yes. The outer bulb (see image above) is the same, but it has to be at least one size larger than that corresponding to the same power of high pressure mercury lamps; i.e. for 75-125W medium pressure mercury the outer bulb has to be of ED28/ED90 size; for 250W it has to be of ED/BT37, ED/BT120, while for 400/450W it has to be of ED145/BT46/BT150.

Q - So, let say, for the first example, we will have an ED28/ED90 fluorescent coated bulb of 75-125W, - isn't it?
A - Yes, you are right! It is similar to the coated 175/250W high pressure mercury lamp.

Q - But there is seemingly one more problem. What about the fluorescent coating? 
A - Now, the problem comes, and it's maybe the most difficult one. It's the one where unpleasant surprises might come during the research... 

Q - Would you consider to use certain luminophores 'as there are' or rather would you try to develop new ones, consisting of mixtures of active substances?
A - For first, the desire may be to use fluorescent coatings as there are used for color light fluorescent tubes and neon signs, and as case might be, mixtures as well.


Q - OK! But you speak about lamps with color light output. And, as you also say, we know that most, if not all, nowadays fluorescent coatings for UV conversion in color light are used in fluorescent tubes, CFLs,  and neon signs.
So, are you sure that if you use these coatings in an 'as-is' form, will these be proper for the compact ED/BT bulb working at high temperature? And will these coatings have a proper conversion for the UV into the colors of light as there work in fluorescent tubes, CFLs, and neon signs?
A - You are right! Here the problem comes in! And here the 'surprises' as well. Only due to testing one by one of the fluorescent coatings would you draw a conclusion...


Q - Is this why you consider to have an oversized outer bulb, to have a lower temperature for the fluorescent coating?
A - Yes, this is one of concerns, of course. And, the more, the ED-shaped bulbs have somehow a larger area than the BT-shaped of the same size, so the 'ED' ones might be preferred.


Q - Can you already expect something as a result, concerning the fluorescent coating?
A - At this stage is too early even to estimate or to speculate, before you have at least some certain results after testing. Anyway, the best desired outcome (preferable with as few testing as possible) will consist in achieving a coating which is sensitive for the peaks of UV spectrum of the medium  pressure mercury lamp, but in order to result a light output efficiency of at least 70lm/W.

Q - Do you mean 70lm/W for any color?
A - For sure not! We mean 70lm/W for the standard white colors used in general lighting, of 2700 to 6500K.


Q - In this case, it seems you consider this type of lamp to be also useful for general lighting. Right?
A - Not necessary at this stage, but as the case might be, if successful, yes. But for now, the intent to achieve the white standard colors is only for the research purpose itself, to find how the results are in comparison with the high pressure mercury lamps and the fluorescent tubes. So, this might be in study at first, and thereafter other color lights will be in study as well.


Q - The depiction above shows uncoated lamps, with clear outer bulb. How does it fit, as long as the research intends to develop fluorescent lamps?
A - Bulbs are shown as been clear (uncoated) for a better understanding of the inside. But, if you ask it, the answer is: Yes, there are needed also the uncoated bulbs. The research will need them for reference, to find the lumen output of the medium pressure mercury lamps, as there are.


Q - What kind of glass has to be the outer bulb, and how large has it to be, for the clear (uncoated) experimental lamps?
A - It has to be the same used for coated bulbs, the same borosilicate glass used for the high pressure mercury lamps, of the size previously discussed. Consider the lamp the same, excepting the fluorescent coating. However, in some cases, if you need to find the UV spectrum of the assembled lamp, then you need also the outer-bulb to be transparent to UV.

Q - So, are you interested to block the UV and to get only the visible light from the uncoated lamps, in most of cases?
A - Yes, excepting some cases, we have to find out only the visible light output of the lamp and other working parameters as well. Measurements made on only the arc tube alone, as are for UV usages, are not conclusive, so we need it in the form and shape of the desired lamp, for also the other measurements, as described above.

Q - Is it true that you seek, or even the research is lucky for,  the case in which you have the optimal burning temperature for the arc tube, while the maximal temperature of the outer bulb at which the fluorescent coating still works properly on long term?
A - Yes! Exactly! This balance is the success of the experiment.

Q - Does the arc-tube need to be in vacuum inside the outer bulb, in order to remain hot while not heating too much the coating?
A - Most likely, yes. And the arc-tube might also be heat-reflective coated at ends.

Q - And, are you sure that with an outer bulb with one size larger than 'normal' would you find this balance?
A - Not! But this has to be the starting point for the experiment.

Q - Do you expect the same colors or color saturation as are for fluorescent tubes?
A - For sure not! You have to take into account that beside the conversion of the UV-C into visible, you have also a certain amount of visible light output. And, on the other hand, if you try to convert also the resulting UV-A into visible, this will also change the spectrum.

Q - Is it possible to get a jumble of unexpected wavelengths conversion leading to unexpected colors, too?
A - There is the likelihood to have unexpected colors that differ to an extent and saturation from that corresponding to the 254nm conversion. The more, if you use mixtures with phosphors for the near UV conversion.

Q - So, have we to expect softer colors (than in fluorescent tubes) due to the bluish-white visible light and due to the conversion of UV-A into visible?
A - We can only speculate so an outcome, but also in this case only the research will give the final result. Surprises may come out, pleasant or unpleasant, as well. But you have to be open to all possibilities...

Q - The most reasonable expectance of the research success?
A - The 75-125W medium pressure UV arc-tube in the ED28/ED90 outer bulb, coated with fluorescent powders used for CFLs of all types, including the high powered for aquarium, hydroponics, and others.

Q - As a conclusion for the attempt to use the coatings used in fluorescent tubes or neon signs for the HID lamps, even let's say of medium pressure mercury?
A - Realistically, you have to move your attention to other compact discharge lamps, with moderate heat output and narrow UV emission (similar to fluorescent tubes), as might be excimer lamps. 
However, excimer lamps are an immature technology from many points of view, while the mercury lamps, as a whole, are a mature one from almost all points of view.
And, for a comprehensive answer, you have to put in balance the disadvantages (as possible mismatching, as resulting from above) of the mature technology of the mercury lamps (as a whole) with the advantages of the still immature technology of excimer lamps.

Q - And, the balance weights in favor of...?
A - The mercury lamps as a whole (fluorescent tubes, CFLs, medium pressure UV, HIDs) at least nowadays, and even, either to proof the maturity of their technology (in case of lack of success of this experiment), or to improve their maturity and portfolio, as the case might be, with the success of this research. May it be even partially or barely successful. 

some more content might come...


Image of medium pressure fluorescent coated mercury lamp with oversized outer bulb (BT46/BT150 for 400W lamp) and arc-tube


Notice!
The oversize of the arc-tube (comparative to that of high pressure mercury lamps) is not a sine-qua-non condition for the lamps in discussion, but the oversizing of the outer bulb is one.



Related post: https://lightcommunitylighting.blogspot.com/2018/05/blog-post_30.html







Cobra's up to date post: http://2012portal.blogspot.com/2020/08/eostres-gift-update.html






Wednesday, 30 May 2018

Untitled Post


The Compact Color Medium Pressure Mercury Lamp



Imagine your Light Community outdoor environment lit with egg-shaped big lamps in all the colours available for neon-signs... You have them no where, excepting some coloured metal halide lamps, in certain colors only.

Proposals for research will come into discussion in order to discuss and achieve lighting sources for esoteric purposes.

A web page will be dedicated for discussion. Till then these only are available:


http://lightcommunitylighting.blogspot.com/2018/04/blog-post_13.html

Look here a random example of neon-signs color range:

https://www.custom-neon-signs.com/Colors

Briefly, in order to achieve each of this color with compact egg-shaped mercury lamp, you have mainly to find so:

- a discharge tube to provide the needed amount of UV in order to irradiate the fluorescent coating of the egg-shaped bulb.

- the needed amount (area of bulb) of fluorescent coating to provide the minimal desired lumen output, if proper irradiated with UVs.

- a proper balance between the heat output of the discharge tube and the size of the (egg-shaped) outer bulb, in order to NOT overheat the fluorescent coating,... which in case of neon signs is not so heat-resistant.


This last item might be the most 'dangerous' one. It might be what prevents a proper color to be achieved and the premature damage of the coating.
This is an important item which the research must solve...


NOTICE!
Discussion about the 'medium pressure mercury lamps' (Ar+Hg) do not include the proposed 'medium pressure neon-mercury discharge lamp', which is a case itself.
This one will use for research the 'common' phosphorous coating for HID mercury lamps. It's main light spectrum is expected to come out from the discharge itself, and will be a reddish based spectrum. Let's say from light-cyclamen to violet-red, depending of the balance between neon and mercury (in discharge terms, not in 'weights').



Here some examples of 'medium pressure mercury':
In that catalogues are some 'low power' already existing (so having 'proof of time') UV medium pressure arc tubes, which (at least theoreticaly) may be used for our proposed medium pressure mercury lamps.
If you or other readers are also in knowledge you will immediately say 'yes' or 'not' as your opinion might be...
The item of interest in the catalogue are the 2 400W medium pressure mercury lamps (arc tubes) which burn in any position (not only horizontal):

HP 4/120 400 125 3.5 120 410 31 105 14.0
and
HP 4/120 SE 400 125 3.5 120 410 31 111 14.0
The arc tube is 31mm length and 14mm dia.

They also run at 120V arc voltage and 3.5A, let say 'nearby' the common HID 400W mercury lamp...
What is also interesting in the catalogue are the Medium-pressure metal halide lamps (not used in general lighting), from which the point of interest is that of 460W

HPM 12 460 120 4.1 800 44 98 22.
The arc tube is 44mm length and 22mm dia.

Thus we might to prefer even a lower power one, this one needs however to be taken in consideration.

On the other hand, we might say that the 'medium pressure' is 'missing' from the metal halide lamps 'portfolio'... The case is also for the sodium lamps...
Here a 250W metal halide UV arc tube. However no arc-voltage and amps.

250 5000089 MHL-250 15.5 68 18 300-450

https://www.ushio.com/files/catalog/uv-mhl.pdf

However the medium pressure MH lamps seem to be weak in the 250-260 nm, while the medium pressure mercury ones seem somehow reach.

Give a look to the bulb in this link:
http://www.fisherylight.com/metal-halide-fishing-lamps/2000W-on-boat-metal-halide-fising-lamp.html

It is a so called 'fishing lamp' (in fact a fish lure lamp used for ocean fishing).

But, of course our point of interest is altogether different, you guess it...

It is a big sized bulb, let say 'big as a house', thus it's not even so... :-)

Consider it to have 200mm/8in dia and an E40/Mog screw cap.

Now! imagine instead of its arc tube (of 2000W) one of the arc tubes above described of 400W medium pressure mercury or metal halide arc tube.

And, the more, imagine it coated with the fluorescent coatings in discussion used for neon signs, or as case for fluorescent tubes.

The arc tube is supposed to provide an amount of UVs, enough to irradiate the large area of the inside coated surface of outer bulb.
However, there is the need of sufficient amount of spectral emission in the appropriate wavelengths which properly match the sensivity (in wavelenghts) of the coating, in order to have a convenable conversion work of the phosphorous.

Now it's ready for research! Of course you need access to a plant where this kind of bulbs are currently manufactured. In Asia there are many, many that can do it at a reliable price.


Discussion to come to imagine the experiment...









[Image posted for educational purpose only]