WE WERE QUITE INTERESTED IN YOUR LETTER OF JUNE 22, 1961, THAT PRESENTED COMMENTS FROM ONE OF YOUR CUSTOMERS, SPELLING OUT THE ADVANTAGES AND DISADVANTAGES OF THE MODEL 1 INCINERATOR AT INSTALLATION B.

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03642A001600040056-9
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 5
• Document Creation Date: December 27, 2016
• Document Release Date: September 17, 2012
• Sequence Number: 56
• Publication Date: July 13, 1961
• Content Type: LETTER

Declassified in Part- Sanitized Copy Approved for Release 2012/09/18: CIA-RDP78-03642A001600040056-9
Dear Sir:
July 13, 1961
ONNDENT AL
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7/1
25X1
We were quite interested in your letter of June 22, 1961, that
presented comments from one of your customers, spelling out the advantages
and disadvantages of the Model 1 Incinerator at Installation B. We
certainly appreciate his careful discussion of the problems encountered. The
job of research and development is merle much easier and more interesting when
the user of equipment makes the effort to discuss the operation of a device
so thoroughly.
Our comments pertaining to each of the points raised by your customer
are indicated below, and are identified by corresponding numbers and letters;
these are the same comments which we discussed on the telephone on July 6:
1. There is no need for comment.
2. The effect of a prevailing wind of between 10 and 15 knots is to
produce a pressure of about 0.1 inch of water in the. system.
three possible ways to combat this. One would be to run the
to the top of the building; thus, the stack opening would be
We can think of
stack all the way
out of the ram
pressure zone on the side of the building and some benefit would be gained from
a helpful aspiration effect by the wind. A second way would be to install a
stainless steel elbow of about 2-inch inside diameter inside the flaw pipe and
pointing outward against the wind; this elbow would have to be supplied from
a special blower, or ducted from the existing blower through a simple inter-
locking damper, in order to direct a jet of air from the elbow along
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Declassified in Part - Sanitized Copy Approved for Release 2012/09/18: CIA-RDP78-03642A001600040056-9
Declassified in Part- Sanitized Copy Approved forRelease2012/09/18 : CIA-RDP78-03642A001600040056-9
tw) kw)
July 13, 1961
of the stack, so as to aspirate the flue-ga
F
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be left on nll the time, so as to help in providing slight additional draft
during operation and to combat the wind action.
We have encountered similar difficulty in connection with the
hundreds of laboratory exhaust fans located on the roofs of our various
buildings. Even without any wind, when any one fan is turned off, the internal
suction provided by all of the other operating fans has tended to pull air back
into the particular building through the inoperative fan. In cold weather,
this cold air entering same of the laboratories has been intolerable. Accordingly,
our building manager devised a very simple steel flap door for use on the
outlet of each exhaust fan. This flap-door device is balanced in a way such
that it hangs open when the fan is operating, but falls shut and thus prevents
backflow when the fan is off. It would also prevent natural flow outward under
calm wind condition, but this probably would be seldom. This would represent a
third way of combatting the prevailing-wind situation at Installation B.
Further, as discussed over the telephone, your idea of using a V-plate to
partially protect the discharge would help same.
3a. The motor driving the fan on this unit was built to operate on
either 50- or 60-cycle current, and the fan was chosen so that sufficient air
would be provided for elevations up to 1,000 feet by the speed resulting from
the use of 50-cycle current. Thus, any failure to deliver enough air so as to
produce the desired cyclonic effect is probably more a result of altitude than
of current frequency. We have observed that, during short periods of opera-
tion on same kinds of paper, no ash remains in the incinerator. However, during
burning periods of 3 hours and longer, we usually end up with several pounds
r..721
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Declassified in Part - Sanitized Copy Approved for Release 2012/09/18: CIA-RDP78-03642A001600040056-9
Declassified in Part- Sanitized Copy Approved forRelease2012/09/18 : CIA-RDP78-03642A001600040056-9
July 131 1961
CONFDENIIAL
of residual ash. The point here is that much of the ash is carried out of the
stack as fine dust, but that gradually the heavier particles can and do ac-
cumulate during extended operation. It is probably reasonable to expect that
reduced air flow increases the accumulation.
3h. It is, of course, true that at an elevation of over 7,500 feet,
the air flow and therefore the burning rate of the device would be reduced.
From the measurements you obtained and from our calculations, we estimate that
at this altitude, the burning rate would be about 70 per centof that Obtained
at sea level.
3c. Theoretically, the ram effect of the prevailing winds on the
stack would be to reduce the amount of air flow. However, we estimate that
this effect in this instance corresponds to only about 0.1 inch of water, which
is quite small as compared to a blower pressure of 7 inches of water.
3d. As we understood it, the 15-1/2-inch blower wheel was used only
a short time; and although it is probably true that the 16-7/8-inch wheel may
not have improved incinerator effectiveness greatly) we would estimate that it
would not impose a much greater load on the motor. We feel that the motor
supplied has sufficient reserve to tolerate such a small increase in load.
3e. This motor was designed and built to run continuously at about
72 degrees Fahrenheit above roam temperature. Thus, it could run as hot as
150 to 170 F, which would be quite hot? to the touchpand yet not really be over-
heating. The starter box is provided with overload heaters which should shut
the motor off if it pulls enough current to overheat. Hence, if the proper size
of heaters has been used in the starter box and so long as they do not shut
the motor off, it is quite probable that the motor is not overheating.
?
Declassified in Part - Sanitized Copy Approved for Release 2012/09/18: CIA-RDP78-03642A001600040056-9
Declassified in Part- Sanitized Copy Approved forRelease2012/09/18 : CIA-RDP78-03642A001600040056-9
Ciis)LI
-4- July 13, 1961
CCg t
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3f. The burning rates claimed initially for the unit were probably
based on sea-level performance, and, as we have pointed out above, at an
altitude of 7,500 feet or more the burning rate would be only about 70 per cent
of that at sea level. It would be helpful if the customer would keep a record
of burning rates obtained over some period of time with various types of paper.
We know that the higher the altitude, the less paper will be burned per unit of
time; and it would be helpful to us to have more data on just how much less
will be burned. We are not surprised to learn that, when attempts were made
to burn bound books or paper, a poker had to be used to spread out the material
collected at the bottom. We have always made it clear that a small amount of
poking is needed in order to achieve complete destruction.
3g. A line voltage of only 205 volts, although within the permis-
sible range for standard motors, is a further complication which causes impaired
performance. For the same horsepower load on a motor, as the voltage drops the
current increases; this alone will cause higher motor temperatures. In
addition, the natural air cooling of the motor is poorer at higher altitudes.
4. The use of an air-intake duct pointed into the wind, as suggested
in the sketch, would do no harm; but, as we have already pointed out, the wind
impact effect is comparatively small as compared to the pressure output of the
fan. Incidentally, if an added intake duct was tried, the inlet to the duct
itself Should be funnel shaped because the natural effect of air flow into the
straight, open pipe is to crowd the flow right at the entrance in a way so as
to cause considerable loss of whatever gain might be realized from the ram
effect.
CC)1\2DE,',91AL
Declassified in Part - Sanitized Copy Approved for Release 2012/09/18: CIA-RDP78-03642A001600040056-9
Declassified in Part - Sanitized Copy Approved for Release 2012/09/18: CIA-RDP78-03642A001600040056-9
-5- July 13, 1961
Thanks again for these helpful comments. We would like to keep in
touch with the application of this unit in the field.
Sincerely
ABW:mlm
In Duplicate
Declassified in Part - Sanitized Copy Approved for Release 2012/09/18: CIA-RDP78-03642A001600040056-9
25X1