SOVIET WORK ON FLAMELESS COMBUSTION

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80-00809A000600330156-2
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 3
• Document Creation Date: December 22, 2016
• Document Release Date: August 26, 2011
• Sequence Number: 156
• Publication Date: July 27, 1950
• Content Type: REPORT

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CLASSIFICATION coNFIDErrrI F "E T A~
CENTRAL INTELLIGENCE AGENCY REPORT
INFORMATION FROM
FOREIGN DOCUMENTS OR RADIO BROADCASTS CD NO.
HOW
PUBLISHED
WHERE
PUBLISHED
DATE
PUBLISHED
LANGUAGE
THIS DOCUIINT CONTAINS INFORMATION AFFECTING THE RATIONAL DEFENSE
or THE DNI11D STATER ?ITNU THE MEANING OF ROPIONANR ACT ND
6 I. I. C.. R~ ANDn11.01 AMR NONE. ITS TR01RMISSION 01 THE REVELATION
OT ITS CGRTN IN ANY MARMIN TO AN MNAOTIORI3RD nRRDN iR -RO?
NIRITRD IT LAM. REPRODUCTION Or TNIR FORM TIED
M. B. Ravich
Dr of Tech Sci
Complete combustion of fuel and very high temperatures may be attained
without any visible flame. This factor offers the possibility of eliminating
large, bulky fuma:es and of constructing smaller and more efficient heating
equipment. Flue gases from the"flameless combustion process do not contain any
products of incomplete combustion and may be utilized in industry and agriculture
as a free source of carbon dioxide and inert gases.
Coal and oil are two fuels which have been widely used up to the present.
But coal, since it requires bulky equipment, is inconvenient for many techno-
logical processes. Liquid petroleum fuel is much more convenient and.produces
higher temperatures. However, its limited availability restricts its use.
Meanwhile, consumption of liquid'motor?fuel by aircraft; automobiles, and trac-
tors, is growing rapidly, and the petroleum industry will be able to release
fewer products for use as furnace. and boiler fuels.
Gas, as a substitute for oil, in gaining in importance. The current
(1911.6 - 1950) Five-Year Plan provides for large-scale development of a new gas
industry designed to-raise the production of gas from coal and shale to 1.9
billion cubic meters end the extraction of natural gas to 8.4 billion cubic
meters. According to plans underground gasification must yield annuallv'920
million cubic meters. The wide utilization of 'coke gas and blast-furnace gas
is also proposed. Production and application of several other gas fuels (from
liquefied gases with heating value about 25,000 calories per cubic meter to
low-calorie gases with heating value of 700 calories per cubic metes) have been
organized.
Adequate supply of gas fuel for industry has to be combined with im-
proved technology since the intensification of gas heating equipment operations
gives great possibilities for increasing the efficiency of equipment without
additional investment..: $oirever; ordinary methods, of ga$ combustion cannot
secure the highest efficiency.
ARMY 14AIR
Scientific - Fuel, flameless combustion
Monthly periodical.
Moscow
Feb 1950
INFORMATION 1950
DATE DIST. 1~ Jul 1950
NO. OF PAGES ?3
SUPPLEMENT TO
REPORT NO.
Vestnik Akademii Nauk SSSR, No 2, 1950
CLASSIFICATION OONI'Iff NTIAL
50X1-HUM I
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New and entirely different methods have been developed recently. The
combustion process proceeds with high speed and without any visible flame if
gas mixed with air is being burned near a surface of incandescent refractories;
for, example, in chamotte tunnels, in the space filled with fireproof checkered
brickwork or in a layer of crushed refractory material. High-combustion speed,
much higher than the speed of the usual methods of combustion, contributes to
the possibility of.decreasing the furnace size approximately 100 times.and also
makes possible the construction of a new type of compact "furnaceless" heating
equipment. The flameless method permits the burning of gas with a minimun ex-
cess of air. This factor provides for the highest temperatures, lower fuel
consumption, and lower loss of heated material. The stimulating effect of in-
candescent refractory surfaces is especially great with the combustion of two
essential types of gas fuel, namely, low-calorie gases with comparatively low
combustion temperature and natural gases with a high content of low-reactive
methane.
Numerous experiments in the combustion of various gas fuels, conducted
by the Power Engineering Institute of the Academy of Sciences USSR, have defi-
nitely established the stimulating action of incandescent refractory surfaces
on the combustion process. For example, only 75 percent of oxyhydrogen gas re-.
acted during a 30-minute period in an empty quartz tube at 900 degrees centi-
grade with-an initial one millimeter vacuum in the system. After filling the
tube with crushed chamotte, 100 percent of the gas reacted in 5 minutes under
similar conditions. Laboratory experiments have established a possibility for
further intensification of the combustion process by using catalytically active
refractory surfaces.
Gas fuel.is used intensively for water-heating boilers in heating systems
for houses and factories. However, the efficiency factor of these boilers is
only 45-55 percent and in the best cases it reaches only 70-80 percent, whereas
a new type of boiler with flameless combustion designed by the Power Engineering
Institute shows an efficiency of 92-95 percent. City utility gas, with a heat-
ing value from 5,030,to 7,770 calories per cubic meter, was burned with four
flameless burners in chamotte tunnels. The air-gas mixture, which failed to
burn entirely in the tunnels, was burned completely in the small space between
the boiler brickwork and lower water-coil pipe. Over-all dimensions of the boiler,
including refractory lining and metal jacket, are as.follows: length, 1.88 meters;
width, 0.65 meter; height, 0.5 meter; volume of refractory tunnels, 5 liters, vol-
ume of free space under the coil pipes, only 50 liters.
The boiler was used to heat production plant buildinW encompassing several
tens of thousands of cubic meters. The maximum thermal load of the boiler reached
240,000 calories per hour and the rate of heat liberation reached 4.5 million cal-
ories per cubic meter per hour, which value surpasses by 10-15 times the rate of
flame furnaces. Heat liberation of the refractory tunnels was 48 million calories
per cubic meter per hour and could be raised to 90 millions. The combustion proc-
ess proceeded with ideal completeness and at'minimum air excess. The oxygen con-
tent was maintained at an 0.6-0.8 percent level which corresponds to an air excess
coefficient of 1.03-1.04. The metal used in constructing a flameless boiler with
a productive capacity of one million calories per hour amounts to only 1.5 tons,
whereas metal requirements for ordinary boilers of similar capacity vary from 6
to 25 tons for various systems. Boilers of the type described were tested suc-
cessfully in large Moscow plants.
The Power Engineering Institute designed two other types of flameless com-
bustion boilers, ENIN-2 and ENIN-4, with still higher efficiency factors. The
ENT-N-4 is designed for use in combination with low-temperature furnaces and driers.
Along with the construction of new types of efficient heating equipment,
good results have been achieved by converting some old equipment to the flameless
CONFIDENTIAL
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process -- a procedure. which has cut fuel c3nsumption almost in half. Especially
high economy may be attained in certain cases by replacing electric furnaces with
flameless combustion furnaces operating on natural gas.
Wide application of the flameless combustion method has been hampered until
recently by some erroneous suppositions. For example, it has been assumed that a
pressure of not less than 0.8 atmosphere and even 1.4 atmospheres should be main-
tained for the combustion of natural gas. However, such a pressure is not always
available in many industrial establishments. Research conducted in the Power En-,f
gineering Institute and under industrial conditions permitted elimination of this
limitation. Flame-less burners are operated satisfactorily with a natural gas
pressure of 0.1 atmosphere.
Another obstacle to maximum efficiency in the combustion of gas fuel was
the fear of combining the operation of premixing flameless burners with high-tem-
perature preheating of gas and air. This fear was based on a supposed danger of
explosion caused by penetration of a combustion zone into a mixing gas pipe. Again,
investigations at the Power Engineering Institute established the groundlessness
of this apprehension and proved the possibility of operating flameless burners
with air preheated to 500-600 degrees.
In addition to conserving. fuel and intensifying the heating process, the
flameless combustion method permits the utilization of the waste products of com-
bustion -- flue gases. The gases, being extremely pure and free of carbon mon-
oxide, may be used as a carbon dioxide fertilizer for green houses. Many USSR
cities are planning-to use the flameless combustion method for economical heat-
ing of green houses with simultaneous utilization of waste gases as a free carbon
dioxide fertilizer. Pure waste gases also may be used for storage of perishable
products in an atmosphere enriched with carbon dioxide: a great many foodstuffs
may be stored over long periods of time without refrigeration.
It-should be noted that the flameless method may also be applied in the
combustion of some liquid and solid fuels.
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