Note: Descriptions are shown in the official language in which they were submitted.
2 ~ ~70~
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APPARATUS FOR AN INCINE~ATOR
BACKGROUND OF THE INV~NTION
Field of the inventio~
The present invention relates to incinerators used to
incinerate noxious medical wastes as well as general
combustible wastes and, more particularly, to a structural
improvement in such incinerators which enables the complete
removal of unburned noxious high molecular materials entrained
in the combustion gas present in the main combustion chamber
and the deodorization and sterilization of the combustion gas
prior to venting the combustion gas into the environment to
thereby prevent the vented combustion gas from polluting the
environment.
Description of ~.he prior art
The prior art waste incinerators include a main
combustion chamber which includes fire-resistant walls, with
the front section of the chamber having a main burner. The
incinerator also includes a recombustion chamber placed above
the main combustion chamber which includes fire-resistant walls
in the same manner as the main combustion chamber, with the
rear section of the recombustion chamber having a recombustion
burner. The main combustion chamber vents its combustion
products to the recombustion chamber through a port formed
between the main combustion chamber and the recombustion
chamber. The port enables the combustion products of the main
combustion chamber to flow into the recombustion chamber.
In the typical incinerator, especially those used for
the incineration of noxious medical wastes such as syringes,
injection needles, blood packs, medical gloves, medical tubes,
or the like, the nearly complete removal of unburnt noxious
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high molecular materials entrained in the combustion gas
flowing from the main combustion chamber and of the
accompanying odor of the combustion gas being vented in the
environment is needed. In order to achieve the above object, it
is preferred to carry out the incineration of such medical
wastes by providing that the flame of the recombustion burner
perpendicularly contact the center of the combustion gas flow,
including the unburnt materials, as the main combustion chamber
combustion gas flows into the recombustion chamber along with
the upward flow of the combustion gas through the port and into
the recombustion chamber.
However, it has been noted that in incinerating such
medical wastes by trying to position the flame of the
recombustion burner so as to perpendicularly contact the center
of the flow of unburnt gas introduced from the main combustion
chamber to the recombustion chamber along with the upward
current through the port, a problem results. That is, the
unburnt gas is directly thrust into the chimney due to the
injection pressure of the flame so that the unburnt gas fails
to sufficiently contact the flame thus preventing the thermal
decomposition of the matter comprising the unburnt gas.
Therefore,the incineration of such medical wastes
using the above described typical incinerator generates waste
materials such as hydrogen chloride from polyvinyl chloride
~PVC) and nylon resin and also results in unburnt gaseous heavy
metals, such as mercury, cadmium and lead, remaining in the
recombustion chamber. Thus the typical incinerator causes
environmental pollution due to the noxious gases present in the
combustion gas being vented into the atmosphere.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention
to provide an incinerator which overcomes the problem of the
prior art incinerators and which nearly completely removes
unburned noxious high molecular materials entrained in the
3 ~ ~
combustion gas of the main combustion chamber and deodorizes
and sterilizes the combustion gas prior to venting the
combustion gas into the atmosphere, thus preventing the vented
combustion gas from polluting the environment.
In accordance with the invention, this object is
achieved with an incinerator comprising a main combustion
chamber including fire-resistant walls in an inner space
thereof and having a main burner in a front section of said
main combustion chamber, a recombustion chamber including fire-
resistant walls and placed above said main combustion chamber,said combustion chamber being provided in a rear section
thereof with a recombustion burner that jets a flame to burn
unburnt gas, the main combustion chamber being operatively
connected to the combustion chamber through a port, and the
recombustion chamber being provided with a gas guide wall for
guiding the unburnt gas; and an exhaust chamber for receiving
and exhausting combustion gas from the recombustion chamber to
ambient atmosphere, the improvement wherein:
- said port is laterally spaced from a center of the
flame jetted from said recombustion burner;
- said gas guide wall is arranged and disposed in the
recombustion chamber relative to the port and the recombustion
burner for guiding a flow of the unburnt gas from the main
combustion chamber through the port so that the unburnt gas is
introduced into the flame jetted from the recombustion burner
in a whirl and in crosswise contact with the flame whereby to
enable complete oxidation of the unburnt gas; and
- said gas guide wall extends upward substantially
from an edge of the port and protrudes in a direction in which
the flame of said recombustion burner is jetted.
The incinerator completely oxidizes, in the
recombustion chamber, the noxious unburnt gas of the combustion
gas of the main combustion chamber and further includes means
for neutralizing hydrogen chloride remaining in the combustion
gas of the recombustion chamber and removes the hydrogen
chloride from the exhaust combustion gas.
~ ~ 4~3Q~ 1
.~,....~
The neut~alizing means comprises an injecto~ nozzle
positioned vertically at the bottom of the exhaust chamber, the
injector nozzle being adapted for letting the combustion gas of
the recombustion chamber whirl upward about the injector nozzle
and exhausted into the atmosphere; and a chemical nozzle fitted
i~
A
CA 02140306 1998-03-20
connected to a chemical tank through a chemical distributing
pipe line, whereby a chemical of the chemical tank is sprayed
from the chemical nozzle into the exhaust chamber so that the
sprayed chemical comes into pressure reducing contact with the
combustion gas whirling upward about the injector nozzle and
neutralizes the hydrogen chloride of the combustion gas prior
to the exhausting of the combustion gas into the atmosphere.
In order to incinerate the many varieties of medical
wastes gathered from numerous medical institutions and packaged
in 20 liter safety packs, an incineration truck provided with
the incinerator of the invention is parked on a place suitable
for incineration of such medical wastes. After parking the
truck on the suitable place, a chimney cover is opened and a
chimney is extended out of the top of the container box. An
injector blower is started so that the combustion gas of the
recombustion chamber can be forcibly exhausted into the
atmosphere.
Thereafter, the recombustion burner is ignited so
that the temperature of the recombustion chamber is raised.
When the temperature of the recombustion chamber has reached
about 1000~C, the waste door of the main combustion chamber is
opened and the 20 liter safety packs containing medical waste
are put into the main combustion chamber so that the safety
packs are heaped on the bottom of the main combustion chamber.
The waste door is closed and the main burner is ignited so as
to raise the temperature of the main combustion chamber to
about 850~C, thus to incinerate the medical waste.
The combustion gas including the noxious unburnt gas
of the main combustion chamber is introduced into the
recombustion chamber along with the upward current through the
port. In the recombustion chamber, the unburnt gas is contacted
again by the flame of the recombustion burner. At this time,
the unburnt gas comes into cross contact with the flame of the
recombustion burner since the port is laterally spaced apart
relative to the flame of the recombustion burner. The unburnt
gas thus whirls so as to be sufficiently agitated and slowly
sucked into the flame of the recombustion burner. The
unburnt gas, therefore, resides in the recombustion chamber for
a time sufficient for the complete combustion of the unburnt
gas.
When using the incinerator having the recombustion
chamber with the gas guide wall extending above the port in the
front of the port, the unburnt gas introduced into the
recombustion chamber whirls along the gas guide wall and comes
into complete contact with the flame of the recombustion
burner. In addition, when the gas guide wall is bent in the
lo flame throwing direction of the recombustion burner, the
unburnt gas will be more smoothly sucked into the flame of the
recombustion burner and the gas agitation effect will be more
improved.
The combustion gas of the recombustion chamber is
introduced into the combustion gas exhaust chamber through the
flue duct and whirls upward about the injector nozzle of the
exhaust chamber and is exhausted to atmosphere.
In order to completely oxidize, in the recombustion
chamber, the noxious unburnt gas of the combustion gas of the
main combustion chamber and to neutralize the noxious hydrogen
chloride remaining in the combustion gas of the recombustion
chamber, a chemical is sprayed from the chemical nozzle, which
nozzle is fitted into the injector nozzle and connected to the
chemical tank through the chemical distributing pipe line.
Therefore, the sprayed chemical comes into pressure reducing
contact with the combustion gas whirling upward toward the
injector nozzle and neutralizes the hydrogen chloride of the
combustion gas prior to the exhausting of the combustion gas
into the atmosphere.
After finishing the medical waste incineration
process comprising the main combustion process, the
recombustion process and the neutralization of the noxious
gases of the exhaust combustion gas, the main burner and the
recombustion burner are shut down. Thereafter, the combustion
blower is stopped so as to reduce the temperature of the main
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combustion chamber. When the temperature of the main combustion
chamber is reduced to a predetermined temperature range of
200~C - 250~C, the ash door of the main
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combllstioll cllanlber is opened alld tlle ash frolll tlle colllbllstion of tlle medical ~vaste is
renloved fron] tlle n~aill combllstion cllamber.
BRIEF DESCRIPTION OF THE DRAWINGS
Tlle above and otller objects~ featllres alld otller advalltages of the present invelltio
~vill be more clearl~ ullderstood from tlle follo~villg detailed description taken il~
COlljllllCtiOIl ~Vitll tlle aCCOlllpallyil]g draWil]gS, ill ~vlliCIl:
Fig I is a side sectional vie~v of an incillerator in accordallce ~vitll a preferred
embodilllellt of tlle present invelltioll, sllo-villg tlle constnlction of the incillerator inslalled
011 an incilleratioll tmck:
~ig. 2 is a plan sectional vie~v of t11e illcinerator according to tlle present the invention;
and
Fig. 3 is a front sectional vie-v of tlle incillerator according to the present the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to tlle drawings, Fig. 1 is a side sectional view of the i~lcinerator in
accordance witll a preferred embodiment of the present invention, showing tlle
constmction of tlle incinerator installed Oll an incineration truck. Fig. 2 is a plan sectional
vie~v of tlle incinerator according to tlle present invention. Fig. 3 is a front sectional view
of tlle incinerator according to the present invention.
Tlle incinerator of tlle invention is particularly used for tlle incineration of a variety of
medical ~vastes collected from medical institutions and packaged in 20 liter safety packs.
As sllo~vll in Fig. 1. tlle inciner~tor 2 is preferably illstalled in a container bo~ loaded on
an incineration truck 1.
Tlle incinerator 2 includes a main colllbllstioll cllamber 4 ~vitll fire-resistant ~valls
constmcted of ceramic fiber blocks and higll strength moldable fire-resistant material. tlle
front section of tlle main combustion cllaltlber is provided ~vitll a main bumer 3. Ille
incillerator 2 also incllldes a recomb~lstioll cllalllber 6 tllat is placed above the main
conlbllstioll challlber 4 and ~hicll illclu~es fire-resistant ~valls constructed of ceramic fiber
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blocl;s. tlle rear section tlle recoltlbllstioll cll~lllber is pro~!ided ~vith ~ recotl1bllstion bumer
5. The maill combllstion cllalllber 4 vellts il7tO tlle recoltlbllstioll cllat1lber 6 t]trougll a port
7 font1ed bet~v~etl ille tllaill cotnbllstiotl c}l~lllber 4 atld tlle recol1lbllstion cllanlber 6.
Tlle rear sectiotl of the ttl~itl colllbllstion cllamber 4 is provided ~vitll a t~aSte door 8 for
insertitlg ~ ast~ into tlle maill combllstioll cllamber 4. Tlle t~aSte door 8 llas a ~vindo~v 9
for observin~ the itlterior of the n1ain cotllbltstion chanlber 4 from the outside of the
challlber 4. The waste door 8 is freely operated by a lifting unit 10 so that the door 8 is
moved vertically in order to opetl or close access to the illterior of tlle combllstion
cllamber 4. Provided itl tlle rear sectiotl of the maitl colnbustion cllamber 4 utlder tl1e
waste door 8 is an ash door 11 for retnoving ash out of the chamber 4.
The main combustion chamber 4 is also provided with a thennocouple 15 operatively
positioned on a fire-resistant wall as sllo~vt1 ill Fig. 3 ~vhich irldicates the temperature of
tlle main combustion chamber 4 at the port 7.
As sl1o~vn in Fig. 2 the recombustion cllamber 6 includes a gas guide wall 12
e~tending above the port 7 and in the front of the port 7. With the gas guide wall 12 the
unbllrnt gas introduced from tlle main combustion chamber 4 into the recombllstion
chamber 6 througl1 the port 7 is guided in tlle direction as shown at the arrow of Fig. 2 so
tllat the unbumt gas is sucked into the effective space of the flame of the recombustion
burner 5 little by little and totally comes into col1tact with the name of the burner 5 in the
effective space. tllus to achieve tlle desired col1lplete combustion of the unburtlt gas.
Tllerefore. tl1ere is no unbunnt gas introdllced il1tO a cotnbustion gas e~haust chamber 13
whicl1 ~vill be described later herein.
In the same manner as described for tl1e main cotnbustion cllamber 4 tlle side ~vall of
tlle recombltstiotl chatl1ber 6 is provided with a then1locollple 16 to indicate tlle
tetIlperahtre of tlle as outlet section of tlle recombltstiot1 cllamber 6. Tlle temperatltres of
~lle maitl combustion cllamber 4 and of tl1e recontbllstiot1 chamber 6 may be con~rolled by
CA 02140306 1998-03-20
a control unit in accordance with temperatures indicated by the
thermocouples 15 and 16 and, in this regard, the incinerator 2
may be automatically operated.
In the embodiment shown in Fig. 2, the gas guide wall
12 extends straight, however, it should be understood that the
top section of the wall 12 may be smoothly bent in the flame
throwing direction of the recombustion burner 5 or toward the
exhaust chamber 13.
Turning to Fig. 1, a combustion blower 19 is placed
in the front of the main burner 3. The combustion blower 19 is
connected to a pair of air inlet ports 20 of the main
combustion chamber 4 through air pipes (not shown) and to an
air inlet port 20 of the recombustion chamber 6 through an air
pipe (not shown), thus to supply the combustion air to both
chambers 4 and 6 and to promote waste combustion in the
chambers 4 and 6. In addition, the lower section of the front
wall of the main combustion chamber 4 under the main burner 3
is provided with a secondary air inlet port 21 for naturally
introducing the secondary air into the main combustion chamber
4. With the air inlet ports 20 and 21, the combustion chambers
4 and 6 are supplied with a sufficient amount of combustion air
so that the combustion efficiency of the incinerator 2 is
improved. As the air inlet ports 20 and 21 cause forcible
introduction of the outside air into the combustion chambers 4
and 6, the air inlet ports 20 and 21 promote the upward air
current in the chambers 4 and 6.
As shown in Figs. 2 and 3, the exhaust chamber 13 is
placed aside the recombustion chamber 6 and connected to the
chamber 6 through a flue duct 14 so that the exhaust chamber 13
is supplied with combustion gas from the recombustion chamber
6. The injector nozzle 17, which vertically extends from an
injector blower 18 placed under the exhaust chamber 13, is
inserted into the chamber 13 and extends to about the center of
the interior of the chamber 13. Therefore, the combustion gas
of the recombustion chamber 6 introduced into the exhaust
chamber 13 is exhausted to the outside of the incinerator 2 or
CA 02140306 1998-03-20
to the atmosphere through a vertically extending chimney 30
when the pressurized air of the injector blower 18 is released
vertically from the injector nozzle 17 in the exhaust chamber
8a
' " 21~03~
A cllemical tank 22 for col1tai~ g a cllel~lical, s~lcl1 as caustic soda or lhIle~vater is
placecl in the front sectioll of tl-e hlterior of the contailler box as sho-vn h1 Fig 1 llle
cllenlical of t!le chenlical tank 22 is pllmped by a pressure pump 23 ar,ld supplied to a
chelnical distriblltillg pipe lil-e 2~ ~vllicll pipe lille 2~ distriblltes tlle pressuri~ed cllenlical
to the interior of tlle main combllstioll challlber ~ and to tlle hlterior of tlle hljector no~le
17 In the hlcillerator. the chelllical of the cllelllical tank 22 is not always distributed to
Ille n~ ll comb~lstioll cll~lnber ~ sllpplied to llle cllambel- 4 ns an enlergellcy ~l~e ~or
reducillg a suddell hlcrease of telllperahlre ill tlle nlain combllstioll chamber ~ The
pressurized cllemical supplied to tlle illterior of the llozzle 17 comes illtO temperatllre
reducing contact with the combustioll gas and neutralizes noxious gases sucll as hydrogen
chloride included in tlle combustion gas, ~vhicll combustion gas wll~rls up-vard about the
nozzle 17 and is e~hausted to the atmosphere
When caustic soda is tlle chemical supplied from the chemical tank 22 to the noz~le
17, the caustic soda comes into tlle temperature reducing contact with the llydrogen
cllloride included in tlle combllstion gas of incinerator 2 and reacts with tlle hydrogen
chloride to form water and sodium ch30ride as ~p~esellted by the following formula,
thereby preventing the exhaust of noxious gases to the atmosphere
.
NaOH + HCI -> NaCl + H20
Tl1e operational effect of the above incinerator will be described hereinbelow witl
reference to Figs I and 2
In order to incinerate a variety of medical ~vastes collected from mlmerous medical
instit ltiOlls and packaged in 20 liter safety packs, the incineration tmck 1 provided witl1
the incillerator 2 is parked at a place sllitable for the illcil1eration of such medical ~vastes
,~fter parkinP the tmck I at the suitable locatioll a cover (not s3lo-vn) of the cllimney 19 is
opened b!~ operatillP a control box 28 pro- id~d il1 tlle rear section of the contailler box of
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',
the tmck l . TllereaRer tlle chi~ ey l9 e~tellds 1lp~vard and projects out of the topofthe
contail1er bo~. The injector blower l 8 is started so tllat tl~e combllstion gas of tl1e
recombustiot1 cl~amber 6 can be forcibly introdllced into tl~e combllstiQIl gas e~hallst
chamber 13 so as to be e~hallsted to tl~e atmospl~ere.
Wl~el1 the ~vaste incil1eration standby state of tlle incil1erator l1as been acllieved the
recomb-lstiol1 bunner 5 of tlle recol21bustion chamber 6 is ignited so that the ilu1er
temperahlre of tlle recombustion cllamber 6 is raised Wl1en the inner temperature of the
recolribllstion chalnber 6 has reaclled abollt 1000 ~C the waste door 8 ofthe main
combllstiol1 chamber 4 is opened by operatil~g the door lifting Ullit l0 and tl~e 20 liter
safety packs 25 colltaillil1g tl1e medical ~vastes are put hlto tlle mail1 combustioll cllamber
so that the safety packs 25 are heaped on tl~e bottoln 26 of tl~e chamber ~. After putting
tlle safety packs 25 in the main combustiol1 chal11ber 4 tlle waste door 8 is closed and tlle
main bumer 3 is ignited so as to raise the temperahlre of the main combustion cllamber 4
to about 850 ~C thus to incinerate the waste. During incineration of the waste tlle
combustion o~gen or tlie combustion air is continuously supplied to the main co~ uslion
chamber 4 thro-lgl1 tl1e air inlet ports 20 and 21 tllereby increasing the combustion
ef3lciency of tlle main combustion chamber 4.
~ he combustion gas including the no~ious unbunnt gas of the main combustion
cl1amber ~ is introdllced into the l~c~ bustion chamber 6 along with the up~vard current
tllrougl1 the port 7 as sl1o~n by tlle arrows of ~ig. l. In the recombllstion cl1amber 6 the
unbllmt ~as is contacted agaiul by tlle flame of tlle recombustion bumer 5. At this time
tlle ul1bllmt ~as comes into cross contact witl~ tlle f~all1e of tlle recombustion bumer 5 as
sllo~vn in Fi_ 2 since tlle port 7 is laterally spaced apart relative to tlle flame of the
recombllstioll bunler so tllat tlle ullbllnlt gas ~hirls so as to be sufficiently a~itated and
slowly sllclied into tlle llame of tlle burner 5. ~s 111e ullbunnt gas is agitated alld ~vlltrls in
tlle recolnbllstiol1 challlber 6 as described above the unblln1t ~as resides h1 t~1e
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reconlbustiotl challlber 6 for a relatively loll~ tiltle sllfficient for complete combllstioll of
the ullb-lt-tlt gas.
~ s showll by the ~rro-vs of Fig. 2, the ullbllrtlt gas is sllf~lcielltly n~i~ed., thus to cause
]ligll temperatllre oxidlltioll ~lld to decompose tlle ullblln1t gaseous hea;~y metals.
As tl1e recombllstion chan1ber 6 hlcllldes the gas guide wall 12 e~tending above the
port 7 hl the front of the port 7 as sho-vll hl Fig. 2. tlle unbllrllt gas introdLlced from the
maill combllstioll chlllllber 4 illtO tlle recolllbustioll chamber 6 througll the port 7 whirls
and conles into colnplete contact witll the fiame of tlle recombustion bumer 5.
Particularly wllell the top section oftlle ~vall 12 is bellt in the flame throwillg direction of
the recombllstion burner 5, the unbumt gas is nlore smoothly guided to tlle flame of the
burner 5 and lhis impro~ es the contact eff ciellcy of the unburnt gas with the flame of tlle
burner 5.
The combustion gas, after being burnt by tlle flame of tlle recombustion bumer 5,
whirls and passes through the flue duct 14 extendillg from the recombustion chamber 6
and is inhroduced to the combustion gas exhaust chamber 13. In the exhaust chamber 13,
the combustion gas wllirls upward about tlle injector nozzle 17 as show~n in Fig. 1, wllich
nozzle 17 is positioned in a vertical mantler at tlle bottom ofthe chamber 13 and e~tends
to about the center of the interior of the c~lamber 13 . Therefore, the combustion gas is
forcibly exllausted to the outside of the incinerator 2 or to the atmosphere througll the
vertically e~tendmg chimney 19. At this time, the combustioll gas smoothly whirls about
tlle injector nozzle 17 as tlle e~hallst chamber 13 is consh~lcted sucll that tlle combllstion
gas inhrodllced from tlle recombllstion chalI1ber 6 throllgll the flue duct 14 smoothly whirls
in the chal11ber 13 and is smootl1ly e~llausted to the ahllospllere along tlle inside wall of
the chall1ber 13.
he COlnbllstiOIl gas. after being bllrnt agaill in the recombllstion cllall1ber 6. tl~e
gaseolls hea~ metals h;l~ e been mostlv decomposed by the higll temperahlre heat of the
flatlle of the recombllstioll burtler 5. Ho~e~er. the hydro~ell chloride llas not beell
3 ~ ~ 7
decomposed but remains in the combustion gas. In order to
remove the noxious hydrogen chlori.de from the combustion gas,
a chemical nozzle 27 which is connected to the chemical tank 22
through the pressure pump 23 and the chemical distributing pipe
line 24 is fitted into the injector nozzle 17. A chemical, such
as caustic soda, of the chemical tank 2~ is sprayed from the
chemical nozzle 27 into the exhaust chamber 13 so that the
sprayed chemical comes into pressure reducing contact with the
combustion gas whirling upward about the injector nozzle 17. By
this process, the noxious hydrogen chloride of the combustion
gas is neutralized through the above-mentioned formula prior to
exhaust of the combustion gas to the atmosphere.
The incinerator 2 of the invention i~ used for
incinerating noxious medical wastes and lets no noxious
material remain in the combustion gas and no microorganisam in
the ash for the waste. Furthermore, the incinerator 2 has no
problem of secondary infection due to the noxious medical
wastes.
In order to show the operational efficiency of the
incinerator of the invention, the following examples were
carried out. The following examples are merely intended to
illustrate the present invention in further detail and should
by no means be considered to be limitative of the invention.
The medical waste incineration procedures of the
examples were carried out, changing the composition of the
medical wastes as represented in Table 1. After incineration of
the medical wastes, the concentrations of the hydrogen chloride
and compositions of the exhaust gases were measured and the
measured results of the concentrations of the hydrogen chloride
are given Tables 2 and 4 and the averaged composition of the
exhaust gases are given in Table 3.
The medical wastes gathered from the medical
institutions were classified into three samples, that is,
sample A, sample B and sample C, as represented in Tables 1 or
the sample classification Table.
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_
The sanlples A. B alld C are dif~erellt froll~ each otller in the ratio of tlle higll
nlolec-llar materials tllereof as sho~vll in Ille follo-villg Table 1. That is tlle ratio of the
hiPIl moleclllar materials of salllple A is lowest ~vllile the ratio of the lligh moleclllar
nlaterials of tlle sample C is hi_llest.
Table 1. (Waste Sample Classification Table)
Sample A Salllple B Sample C
Classification Ratio Weigllt Ratio Weigllt Ratio Weight
Plastics 42.21688 45 1800 50 2000
Tubes 9.2368 15 600 26 1040
Papers
fibers 37.6 1504 23 920 9 360
Neddles 1.1 44 2 80 3 120
Glass 8.9356 14 560 11 440
Rubber 1.040 1 40 1 40
Sum 100.0% 4000g lOO.O~o 4000g 100.0% 4000g
The concentrations of the hydrogen cllloride included in the combustion gases after
individllal incineration processes of the samples A B and C were measured and tlle
measurin-~ results are given in Table 2.
Table. 2 (Concentrations of the Hydrogen Chloride withollt processing tlle
Neutralization)
Sample A Sample B Sample C
Concentratioll of
HvdroYen Cllloride
(mP/Nm3) 46 100 101
As represented in tlle Table 2 the concentration of the llydrogen chloride ~vllen
incineratill~ the sample A ~vhose ratio of the hi81' molecular materials was lowest ~vas 46
mg Nnl3. tlle concelltration of the hydrogell cllloride ~vllen incineratillg the sample B ~vas
100 m~~ m3. and tlle concentration ofttle llydrogell chloride ~vllen incineratin~ the
sanlple C ~-hose ratio of tlle lli~11 moleclllar n~aterials ~vas lligllest ~vas 101 m_'N1ll3.
CA 02140306 1998-03-20
Therefore, it is noted that all of the concentrations
of the hydrogen chloride in the combustion gases of the samples
A, B and C are remarkably lower than the reference ratio 700
mg/Nm3.
The compositions of the exhaust gases after
incineration of the samples A, B and C where measured and the
averaged composition of the exhaust gases is given in Table 3.
Table 3 (Averaged Composition of the Exhaust Gases of the
lo Samples A, B and C without neutralization process)
Measured Reference
Content Unit Value Value
Smoke g/Nm3 0.027 0.25
Amount of sulfur oxideNm3/h < 0.02 0.032
Concentration of
Sulfur oxide ppm <10
Nitrogen oxide ppm 45 250
Cadmium mg/Nm3 < 0.05
Lead mg/Nm3 < 1
Fluoride mg/Nm3 < 2
Hydrogen Cyanide mg/Nm3 < 0.5
Mercury mg/Nm3 0.05
Ammonium ppm < 1
30 Chromium mg/Nm3 < 0.2
The results of the averaged composition of the
exhaust gases shown in Table 3 was from the incineration of the
samples A, B and C merely through the main combustion process
and the recombustion process without the neutralization process
of the present invention. In order to comparatively show the
operational efficiency of the incinerator with the neutralizing
means, the samples A, B and C were incinerated through the main
combustion process, the recombustion process and the neutra-
lization process, and the concentrations of the hydrogen
CA 02140306 1998-03-20
chloride were measured and the results are given in Table 4.
Table 4 (Concentrations of the Hydrogen Chloride with
processing the Neutralization)
Sample A Sample B Sample C
Concentration of
Hydrogen Chloride (mg/Nm3) 15 20 25
As represented in the Table 4, the concentration of
the hydrogen chloride when incinerating the sample A was 15
mg/Nm3, the concentration of the hydrogen chloride when
incinerating the sample B was 20 mg/Nm3, and the concentration
of the hydrogen chloride when incinerating the sample C was 25
mg/Nm3.
Therefore, it is noted that all of the concentrations
of the hydrogen chloride in the combustion gases of the samples
A, B and C are remarkably lower than those of the combustion
gases without the neutralization process of the present
inventlon .
As described above, the incinerator of the present
invention has a port for introducing the combustion gas of the
main combustion chamber into the recombustion chamber, which
port is positioned such that the port is laterally spaced apart
relative to the flame of the recombustion burner to enable the
combustion gas vented into the recombustion chamber to come
into cross contact with the flame of the recombustion burner.
With such port, the unburnt gas in the combustion gas whirls so
as to be sufficiently agitated in the recombustion chamber. The
unburnt gas is, therefore, resides in the recombustion chamber
for a relatively long time and this causes the unburnt gas to
be completely burnt in the recombustion chamber, i.e. increases
flame contact time and hence burning time. Hence, the gaseous
noxious heavy metals will be nearly completely removed from the
exhaust combustion gas. Furthermore, the incinerator deodorizes
the combustion gas prior to exhaust of the gas.
CA 02140306 1998-03-20
When incinerating the medical wastes using the
incinerator of the present invention having the gas guide wall
in the recombustion chamber, which wall extends above the port
in the front of the port, the combustion gas including the
.1~
15a
21~03~6
mail1 comb1lstiol1 cllamber challges its direction of flow and is sucked into tlle effective
space of tlle flame of tl1e recolllbllstioll b1lmer little by little. Tllerefore, tlle ul1b1lmt gas
mostly con1es into contact with the flallle of tlle recombustion burner in the effective
space, and thereby achieves the desired complete combllstiol1 of the unb1lmt gas. Hence,
there is no ullbllnlt gas introduced into tlle conlbllstioll gas e~l1aust chal11ber.
In the case of use of tlle incinerator having the g~s guide wall, ~vl1icl1 guide ~vall
extel1ds above tlle port in tlle frol1t of tlle port alld the top section of wl1ich ~vall is
smoothly bent in the flame tllrowing direction of tlle recoll1bllstiol1 bumer, the ullburnt gas
is more smootl1ly guided to tlle flame of tlle recombustion bumer and this impro-~es the
contact efficiency of the unb1lrnt gas with tlle flame of the bumer.
II1 addition, tlle incinerator of tlle present invention incl1ldes noxio1ls gas neutralizing
means for neutralizing noxio1ls gases, sucll as hydrogell cllloride, of tlle comb1lstion gas of
tlle recombustion chamber using a chemical and for relnoving the noxious gases from tlle
combustion gas prior to the exhausting of the combustion gas into the atmosphere. The
noxio1ls gas neutralizing means includes the injector nozle positioned vertically at tlle
bottom of the exha1lst chamber and extends to about the center of the interior of tlle
cllamber. The combustion gas introduced into the exl1aust cllamber whirls up-vard about
the nozzle and is e~l1austed to the atmosphere through the vertically extendillg chimney.
The neutralizing means also includes a chemical tank for cont~ining a chemical such as
caustic soda or limewater, wllich tank is placed in the front section of the interior of the
container box of the incineration tmck. The neutralizing means filrther includes the
cl1emical nozzle, wl1icl1 chemical nozle is fitted into the injector nozle and connected to
the cllemical tank tllrougll the press1lre p1lmp and tlle cllemical distributing pipe line. With
the neutralizil1~ mealls. tlle cllemical such as caustic soda of the cllemical tank is sprayed
from tlle chemical nozzle into the exlla1lst cllamber so that tlle sprayed chemical comes
hlto press1lre reducin~ cont~ct wi~h the combllstion gas whirling upward about the injector
nozle and ne1ltralizes tlle no~ious llydro~en chloride of the combustiol1 ~as prior to
16
~_ 21403~
e~llallst of tlle coml~llstioll gas. Tllerefore, tlle illcillerator of Ille presellt inventioll Wi~ll tlle
nelltralizillg means callses no envirollltlelltal polllltioll and is not bad for the healtll.
~ lotller advalllage of tlle incillera~or of tlle illve1ltioll is 111at tlle incinerator has a
sterilizing effect alld lets llo llo~iOIls Illaterial relllaill in ~lle e~llallst colnl~llstion gas and no
n~icrOorgallisln in tlle asll of 111e wastes, alld llas llo problem of secondary infectioll due to
tlle no~ious medical wastes.
Altllougll tlle preferred e~ odilllellts of tlle presellt illvelltiolt have been disclosed fior
illllstraiive pllrposes, those sl;illed ill tlle ~rt will appreciate tllat various modificatiolls,
additions and s~lbstihltiolls are possible, witl]ollt departing from tl]e scope and spirit o~tl]e
im~entioll as disclosed in tlle acconlpanyillg claims.
