Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1905-02-23
MUNICIPAL ELECTRIC PLANT
The Engines Completed and Sub.
jected to High Pressure Test.
Much Of the wiring Apparatus 1iaN
Arriycd-Mcn Mt Work setting
r,o,cs-Iuoue 10 start Plant Next
Mouth-l.atcst improvements.

FORM Tho boilers are erected ana
ready for steam. the mechanical draft
plant and the economizer are ready Tor
service and tho engines are on their
foundations. The electric generators
are ready to assemble and two car
loads of switchboard material and
transformers are waiting to be UNI
loaded. There have been number OF
poles set on the side streets In the
north end of the town and considerable
of tho wiring supplies are ready for
use rs soon as the balance of the poles
can be erected. owing to the severe
weather the digging of the holes has
been delayed, but is now proceeding
rapidly.
The boilers are OF the water tube
type and consist of two cross steam
drums. which are connected with nu-
mcrous small tubes through which the
water circulates at n rapid rate, thus
enabling n large quantity TO come in
contact with the heated tubes nearest
the fires. The water is then carried
into the large cross drums. where the
steam disengages and passes to the
steam drum above. From this steam
drum it is drawn off to the engines.
| inc pOier Is eQulppcO WIN Nv" S"'~''
valves aud during Il recent test in the
presence Of Professor Freedman with
stood a hydraulic pressure of go
pounds. The working steam pressure
lis $50 pounds and each boiler will de-
liver 1850 boiler horse power this rep
rescnts the evaporation of about 6oo
gallons of water each hour or about
as much as 10 good sized barrels Will
hold. These boilers are set in brick
ma sorry, which was built by Contrac-
tor stone and so we'll constructed that
no crack or other defects have devcl-
opcd during the drying out.
From the top of the boile"s the hot
gases arc carried in sheet iron smoke
fucs to the steel stack. BY an ingenious
arrange mcnt of hampers the gases car.
be either taken through the ecoromizer
or carried direct to the stuck. If tncy
are taken through the sconomizer a ran
is used to facilitate Their progress ana
induce Il draft in order TO burn the
amount of coal necessary 20 cvaporate
The water into steam.
The far is driven by a small steam
lcngine ara will handle an enormous
lcuantity of hos gas each minute. BY
regulating tl," speed of the fan the proper
air pressure can be carried in the ash
u.ts and a constant boiler pressure MAIN
ia ined with all changes of load. This fan
las IL bearing around which water IL
circulated to keep it cool.
The oconomi:.er is n nest of cast iron
tubes set on end which is placed between
the boilers and IN, stack. These tubes
arc filled with water which Will be used
in the boilers and as it comes in contact
with the hot gases it is heated to a higl
. temperature 50 that when it goes to tho
boilers it will immediately become steam
ibis makes n great saving in the amount
OF coal necessary to operate the plant
7, Py this arrangement it is possible to hea
= the water to $50 degrees Fahre nheit be
fore pumping it into the boilers. 1t wa!
recently tested with $50 pounds hydraulic
prcssur, and remained tight in all thu
joints 1t is said to he the only ono II
Burlington. Economizcrs have heci
= Eno VII to save as much as Il per cent
Of the fIci used.
In the basement of the engine room ar
: located the boiler feed pumps in duplicat
so that either can supply the whole boile
= capacity. These are of the ram patter
L with brass plungers and outside packe
: pistons, so that any leakage san be a
once detected. Near them on the sam
level is located the condenser. This
y of the jet pattern. in which tho steai
c from the engine exhaust comes in con
tact with a spray of water and is a
II once condensed producing vacuum whic
l. adds much to the power and efficiency q
the operation of tho engine. The waite
II is taken from the lake by the circulatin
!. pump and returned by Pinch cast iro
II 20 per cent of the fuel necessary I
s. operate an engine without them.
u The engines are of tho tandem con
Is pound type. each rated at 20)-horsc pow6
Is and run at Il speed of 257 revolutions pc
W minute They arc to lie directly connect
cd to the dynamos. that is tho revolvin
part will be mounted on an extension
the engine shaft so that no belts will
=. used.
=. The engine bearings arc massive an
are supplied with rings which rcvovc @
the shaft and dip into an oil we'll. TIL
supplies a continuous stream of oil on tt
Ia ;op of the bearings The low pressul
I. cylinder is in front of the high pressul
,. cylinder so that the piston OF the latte
"a can be drawn through without disman
FL ling the whole engine. This is a modcl
feature and only found on the newe
types. The cylinder Is overhung so tn;
when heated with the steam il can p,
o. pand freely and not disturb the alig1
r. mcnt
II, The engines arc mounted on massi'
* concrete foundations which weigh abo
n, 20 tons each.
G. Tho dynamos consist Of ring
n. iron about eight feet in diameter al
It. n revolving part which Is mounted {
the shaft OF the engine. On these al
- the wires which are used to genera
the electricity. The dynamos genera
pressure at $500 volts and supply thr
phase alternating current. This cu
rent is then carried to transformer
which supply the arc lighting systel
Tho revolving part is built on ste
casting and has mounted on it rs pol
projections of thin wrought iron shee
around which is wound strip copp
III bent in shape on edge. which arrang
ment affords very complete ventilati'
I'LL for both the fields and the armatul
A small dynamo Is mounted on the eI
of the shaft OF the largo machir
which supplies the current necessa
to magnetic tho fields. This also
an improved arrangement over 4
older form where a belt is used {
connecting the two machines.
- The switchboards are being unloa
ed from the cars. but have not yet be
y" taken out of their boxes. These n
said TO be very fine pieces OF mocha