[Gasification] back on-track [was] off topic discussion

[Mike Weaver]

I agree, but this is pretty much a volunteer operation and both Tom and 
I have to keep ourselves solvent. If I get enough time I'll see if I can 
hypermail or MohnArc the archives.

-Mike


Peter Singfield wrote:

>Tom and Mike;
>
>It would be really great if the Archives could be searched in a complete
>and proper manner.
>
>In this present example -- "grate" -- and allowing results in programmable
>config -- such as by date -- or where another word needs by there
>(refractory -- or stainless -- etc)
>
>When I tried the Google search engine it did not point to the Gas list
>archives -- but the entire I-net -- very confusing!!
>
>I haver archived many of the past discussion -- if time today I will look
>through those older ones and post some as examples.
>
>I see a lot of questions repeated that were so completely well answered in
>entire threads years gone by.
>
>Such as producer gas production from oils --- blue gas -- water gas -- etc.
>
>All with math models in place -- clear explanations -- and so9 many hard
>references to other sources.
>
>Maybe organizing the Arcs should be a top priority project??
>
>As mentioned -- people could research first -- then ask questions later --
>referring to specific past postings.
>
>This would greatly advance gasification projects.
>
>OK -- just went and picked one fast example -- from 2000 -- see appended
>
>There is so much technical resources in those archives -- so very much --
>if we have accomplished anything -- it is that.
>
>Peter/Belize
>
>At 08:56 PM 5/1/2007 -0700, Tom Miles wrote:
>  
>
>>We have seen the "August 2004" problem before. Sometimes we have had
>>problems with the software rebuilding the archive when we've changed
>>servers. If it's broken Mike will fix it for us.   
>>
>>The archives should go back to 1996 when we started the list. If the early
>>ones don't show up on the Google search on the gasification site
>>(http://gasifiers.bioenergylists.org/ ) they will show up on a Google web
>>search. That's why we put them in the format we did when we created the
>>list. 
>>
>>Tom
>>
>>    
>>
>
>***************appended************
>
>Date: Sun, 24 Sep 2000 07:59:54 -0500
>To: gasification at crest.org
>From: Peter Singfield <snkm at btl.net>
>Subject: GAS-L: Power From Solar Heat (1913)
>
>
>Folks -- the list has been kind of slow lately. I know the following is off
>topic -- but just went through the chore of scanning this all in. figured
>some of the old timers on this list will get a chuckle or two out of it.
>
>So -- a blast from the past ---
>
>Peter Singfield
>Belize
>
>****************************************
>
>OK --- Scanned in from my:
>
>"Marks Mechanical Engineers Handbook"
>
>Published: 1924 (MacGraw-Hill Book Company)
>
>
>POWER FROM SOLAR HEAT
>
>The heat received per minute from the sun on 1 sq. ft. of surface normal to
>the sun’s rays above the atmosphere of the earth amounts to 7.12 B.t.u.
>(0.168 h.p. per sq. ft.), but, before reaching the earth where it can be
>utilized, part of this heat is absorbed by water vapor and dust suspended
>in the, atmosphere. In vast areas in the tropics and in certain
>semi-tropical and arid sections (e.g., Arizona, Egypt), however, the air is
>dry and clear, this loss is small, and sun power can be profitably produced
>provided coal is very expensive and the cost of the considerable land area
>required for a plant is low.
>
>A. S. E. Ackermann (Jour. Roy. Soc. Arts, Apr. 30, 1915) states the
>theoretical thermal efficiency of a solar heat absorber to be e = [Dsa — pk
>* (T to the 4 rth — 2/3A to the 4 rth) — (1 — r)Dsa]/Dsa, where:
>
>D = width of reflector, ft.; 
>
>s = solar constant = 7.12 B.t.u. per sq. ft. per mm.; 
>
>a = coefficient of atmospheric transmission = 0.7; 
>
>p = perimeter of boiler, ft.; 
>
>k = boiler radiation constant 10 to the minus 16 * 0.36 B.t.u. per sq. ft.
>per mm.; 
>
>T = boiler temperature, deg. fahr. abs.; 
>
>A  = temperature of reflectors, deg. fahr. abs. (= atmos. temp. + 9 deg.); 
>
>r = efficiency of silvered glass as a reflector of heat — taken as 0.6. 
>
>Also, theoretical overall thermal efficiency of a sun-power plant = e1 = e
>* (T — 568)/T, where 568 is the absolute temperature of the condenser, deg.
>fahr. (assumed constant). 
>
>In the Cairo plant, D = 12.67 ft. and p 2.92 ft. Assuming A 561 deg. and
>solving equation for e1 for various values of T and plotting the results,
>it is found that the maximum value for e, (5.9 per cent.) is obtained when
>T = 231 deg. (= 692 deg. abs.) or the temperature for a steam pressure of
>21 lb. abs. The actual maximum overall efficiency of the plant was found to
>be 4.32 per cent., showing that about 75 per cent, of the boiler h.p.
>theoretically possible was obtained.
>
>In a 50-b.h.p. plant installed in 1913 at Cairo, Egypt, by Frank Shumann
>(Manchester Assn. of Engrs., March 14, 1914), the sun’s rays are
>concentrated on the flat bottom of a cast-iron boiler by silvered panes of
>ordinary window glass arranged in frames so as to form approximate
>parabolic reflectors, which frames are so geared that the engine (working
>through a friction clutch governed by a thermostatic device) intermittently
>turns them and keeps them facing the sun throughout its course during the
>entire day. This boiler generates steam at atmospheric pressure (14.7 lb.
>per sq. in.) which is utilized in a specially designed condensing engine
>that yields 1 b.h.p. on a consump­tion of 22 lb. of steam. (For larger
>plants the use of low-pressure turbines is proposed.) 
>
>When the sun is obscured by clouds the engine will continue to generate
>power economically until the pressure drops to about 4 lb. abs. To provide
>power over rainy spells of 2 or 3 days, additional plant must be provided
>to heat water to 212 deg. for storage in insulated tanks. The latitude of
>Cairo is 30 deg. N.; at a location 1000 miles nearer the equator the Cairo
>plant would yield 65 b.h.p.
>
>The steam-producing part of the Cairo plant cost $7600. With interest and
>depreciation at 10 per cent., the annual charge would be $760. An
>equivalent coal-burning plant with stack, boiler and buildings would cost
>$3750, and the annual charge at the same rate would be $375, or $385 less
>than for the sun-power plant. Assuming a coal consumption of 2 lb. per
>b.h.p. hour, the fuel annually required for 365 ten-hour days would amount
>to 163 long tons. 
>
>That is, the sun-power plant will compete on an even basis with a
>coal-burning plant using coal costing but ($385/163 =) $2.36 per long ton.
>For particulars regarding sun-power plants using less efficient heat
>absorbers consisting of shallow, glass-covered, water-filled wooden basins
>of large area, and also the use of ether or sulphur dioxide as the working
>fluid instead of steam, see articles by Messrs. Shumann and H. E. Willsie,
>Eng. News, May 13, 1909. A brief sketch of former efforts to utilize solar
>energy, and a bibliography of the subject, are included in the paper by Mr.
>Ackermann cited above.
>
>
>*****************************************
>
>HOT-AIR ENGINES
>
>Hot-air engines are heat engines in which air is employed as the working
>substance, operating in the Stirling or Ericsson cycles (see p. 327) or
>modifications of them. Their bulk per h.p. of capacity is great as compared
>to steam or gas engines and their efficiency low. They find use, however,
>in small sizes for domestic pumping work. Bryan Donkin (“ Gas, Oil and Air
>Engines”) gives the following data on such motors:
>
>            Cyl.  Stroke
>Engine    dia in.  in.  Rpm   Ihp    BHP 	Lb. fuel per hr. per
>                                          Ihp	Bhp
>Buckett	24.0	16.0	61	20.20	14.40	1.8	2.5
>Beniér	13.4	13.8	117	5.80	4.00	8.1	8.6
>Bailey	14.6	6.9	106	2.40	1.30	4.2	7.6
>Rider	       6.7	9.5	138	0.81	0.23
>
>The actual thermal efficiency of the Buckett engine, assuming the fuel
>(coke) to have a calorific value of 12,000 B.t.u. per lb., is 2546/(2.5 X
>12,000) = 8.48 per cent. Similarly, that of the Bailey engine is 2.8 per
>cent. A steam engine of the size and speed of the Buckett engine, with a
>mean effective pressure of but 30 lb. per sq. in., would develop over three
>times the indicated horse power.
>
>
>***********************
>
>There -- that should keep you busy. If you could you get the refs referred
>to here:
>
>"For particulars regarding sun-power plants using less efficient heat
>absorbers consisting of shallow, glass-covered, water-filled wooden basins
>of large area, and also the use of ether or sulphur dioxide as the working
>fluid instead of steam, see articles by Messrs. Shumann and H. E. Willsie,
>Eng. News, May 13, 1909. A brief sketch of former efforts to utilize solar
>energy, and a bibliography of the subject, are included in the paper by Mr.
>Ackermann cited above."
>
>Probably would answer a lot of questions regarding refrigeration working
>fluid "boilers" and power plants.
>
>Peter
>
>
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>
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