U.S. patent application number 12/277613 was filed with the patent office on 2009-10-08 for continuous steam pyrolysis apparatus and pyrolysis furnace therefor.
Invention is credited to Kalitko Uladzimir, Chun-Yao Wu.
Application Number | 20090250332 12/277613 |
Document ID | / |
Family ID | 41132252 |
Filed Date | 2009-10-08 |
United States Patent
Application |
20090250332 |
Kind Code |
A1 |
Wu; Chun-Yao ; et
al. |
October 8, 2009 |
CONTINUOUS STEAM PYROLYSIS APPARATUS AND PYROLYSIS FURNACE
THEREFOR
Abstract
A continuous steam pyrolysis device and a pyrolysis furnace
therefor are provided. The device comprises a heat generator, a
combustion chamber and a superheated steam generator. The
combustion chamber comprises a reaction chamber with a charge
opening and a discharge opening, and one or more axial transporting
structures installed in the reaction chamber, wherein each
transporting structure has a central axis and comprises one or more
proceeding zones and one or more blending zones. The total length
of the blending zones along the central axis direction ranges from
about 5% to about 35% of the length of the transporting
structure.
Inventors: |
Wu; Chun-Yao; (Gangshan
Township, TW) ; Uladzimir; Kalitko; (Gangshan
Township, TW) |
Correspondence
Address: |
HOLLAND & KNIGHT LLP
10 ST. JAMES AVENUE
BOSTON
MA
02116-3889
US
|
Family ID: |
41132252 |
Appl. No.: |
12/277613 |
Filed: |
November 25, 2008 |
Current U.S.
Class: |
202/94 ;
202/262 |
Current CPC
Class: |
Y02P 20/143 20151101;
C10B 47/44 20130101; C10B 51/00 20130101; C10G 1/10 20130101; C10B
53/07 20130101 |
Class at
Publication: |
202/94 ;
202/262 |
International
Class: |
C10B 35/00 20060101
C10B035/00; C10B 9/00 20060101 C10B009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 7, 2008 |
TW |
097112500 |
Claims
1. A pyrolysis furnace for a continuous steam pyrolysis apparatus,
comprising a reaction chamber with a charge opening and a discharge
opening, and one or more axial transporting structures installed in
the reaction chamber, wherein each of the transporting structures
has a central axis and comprises one or more spiral segments and
one or more paddle segments, and the total length of the paddle
segments along the central axis direction ranges from about 5% to
about 35% of the length of the transporting structure.
2. The pyrolysis furnace as claimed in claim 1, wherein the total
length of the paddle segments ranges from about 10% to about 30% of
the length of the transporting structure.
3. The pyrolysis furnace as claimed in claim 1, wherein the
transporting structure has a plurality of spiral segments and a
plurality of paddle segments that are alternately arranged with
each other; and each of the spiral segments is substantially
identical in length and each of the paddle segments is
substantially identical in length.
4. The pyrolysis furnace as claimed in claim 1, wherein the
reaction chamber comprises a plurality of reaction regions
communicating with one another, and each of the reaction regions
comprises one said transporting structure.
5. The pyrolysis furnace as claimed in claim 4, wherein the
reaction chamber comprises two reaction regions.
6. The pyrolysis furnace as claimed in claim 1, which is used for
the treatment of waste tires.
7. A continuous steam pyrolysis apparatus, comprising: a heat
generator; a combustion chamber communicating with the heat
generator, comprising: a reaction chamber with a charge opening and
a discharge opening; and one or more axial transporting structures
installed in the reaction chamber, wherein each of the transporting
structures has a central axis and comprises one or more proceeding
zones and one or more blending zones, and the total length of the
blending zones along the central axis direction ranges from about
5% to about 35% of the length of the transporting structure; and a
superheated steam generator communicating with the reaction
chamber.
8. The apparatus as claimed in claim 7, which further comprises a
steam generator communicating with the superheated steam
generator.
9. The apparatus as claimed in claim 7, wherein the total length of
the blending zones ranges from about 10% to about 30% of the length
of the transporting structure.
10. The apparatus as claimed in claim 7, wherein the transporting
structure has a plurality of proceeding zones and a plurality of
blending zones that are alternately arranged with each other, and
each of the proceeding zones is substantially identical in length
and each of the blending zones is substantially identical in
length.
11. The apparatus as claimed in claim 7, wherein the proceeding
zones are spiral segments and the blending zone are paddle
segments.
12. The apparatus claimed in claim 7, wherein the superheated steam
generator is tube-shaped and surrounds the outside of the reaction
chamber.
13. The apparatus as claimed in claim 7, wherein the reaction
chamber comprises a plurality of reaction regions communicating
with one another, and each of the reaction regions comprises one
said transporting structure.
14. The apparatus as claimed in claim 13, wherein the reaction
chamber comprises two reaction regions.
15. The apparatus as claimed in claim 7, which further comprises a
pyro-oil-gas processing system at the downstream of the reaction
chamber, wherein the pyro-oil-gas processing system comprises a
purifying device, a condensing device, and optional, an oil-water
separating device and/or a waste water processing device, and the
purifying device is a high-temperature filtering device and
communicates with the superheated steam generator.
16. The apparatus as claimed in claim 15, wherein the condensing
device comprises two or more condensers in series, wherein the
condenser at one end communicates with the heat generator, and the
condenser at the other end communicates with the purifying device
and is provided with an U-type pipe for passing cooling water.
17. The apparatus as claimed in claim 7, which further comprises a
pyro-solid-material processing system at the downstream of the
reaction chamber, comprising: a sorting machine; a magnetic
separator; and a grinding machine.
18. The apparatus as claimed in claim 7, which is used for the
treatment of waste tires.
19. The apparatus as claimed in claim 7, which further comprises a
pre-processing device at the upstream of the reaction chamber,
communicating with the reaction chamber through the charge opening,
wherein the pre-processing device is a cutting machine.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Taiwan Patent
Application No. 097112500 filed on 7 Apr. 2008, the contents of
which are incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a continuous steam
pyrolysis apparatus, and more particularly, relates to a continuous
steam pyrolysis apparatus having a unique transporting structure,
which is especially used for the treatment of waste tires.
[0004] 2. Descriptions of the Related Art
[0005] Waste tires are generally recycled in two methods. The first
method is the physical processing method, in which the waste tires
are broken up, then the steel wires, nylon and rubber are
separated, and finally the rubber is recycled in a form of raw
rubber. However, as a recycled material, the recycled rubber has
poor quality and is inappropriate for use as a raw material to
produce tires. The recycled rubber thus obtained has a low resource
utilization factor and is less economical. The other processing
method incorporates a chemical process, in which the waste tires
are broken up after adding an appropriate percentage of catalyst.
The waste tires are then pyrolyzed at an appropriate temperature
and an appropriate pressure to produce gaseous products, blended
oils, carbon black, residuals and the like. Then, with an
appropriate separating process such as the fractionating process,
the byproducts with high economical value such as light oil,
gasoline, kerosene, diesel oil and heavy oil may be separated from
the blended oils. Recycling waste tires are, thus, more
efficient.
[0006] It can be seen from the above description that the pyrolysis
method for processing waste tires delivers a substantially better
recycling economical benefit. Therefore, most of the related
development efforts under way at present are directed to such a
method. Conventional waste tire pyrolysis technologies may further
be divided into two categories, namely, pyrolysis-in-batch
technologies and continuous-pyrolysis technologies. For the
pyrolysis-in-batch technologies, waste tires are placed into a
pyrolysis furnace which is then heated to activate a pyrolysis
reaction. After completing the pyrolysis reaction, the processing
procedures such as cooling and depressurization are conducted and
pyro-products are taken out. Thereafter, another batch of waste
tires can be placed into the furnace for processing. This approach
is disadvantageous in that the pyrolysis furnace must be subjected
to a heating/cooling cycle for each batch and the pyrolysis
reaction has to be interrupted between the individual batches,
resulting in a limited processing speed and a low production
throughput. Furthermore, after processing each batch, the pyrolysis
furnace has to be opened to take out the reaction products before
the next batch of materials to be pyrolyzed can be loaded. This
makes it difficult to effectively use gases that result from the
pyrolysis reaction, and tends to cause the escaping of dusts and
pyro-gases. Nowadays, waste tires are mostly processed through the
continuous pyrolysis method to save time and costs, increase the
production throughput and decrease hazard to the environment.
[0007] Continuous pyrolysis apparatuses commonly used at present
can be divided into two categories: continuous pyrolysis-in-batch
apparatuses and continuous pyrolysis apparatuses. A continuous
pyrolysis-in-batch apparatus is disclosed in Taiwan Patent
Publication No. 366304. This continuous pyrolysis-in-batch
apparatus uses a plurality of pyrolysis furnaces in parallel,
wherein each of them is controlled independently from each other,
so that these parallel pyrolysis furnaces may be operated in
sequence to accomplish a continuous pyrolysis. That is, when the
pyrolysis reaction carried out in each pyrolysis furnace is
completed, the pyrolysis furnace is cooled down independently, and
then the pyro-products are withdrawn and a next batch is loaded.
However, even though the pyrolysis reaction can be performed
continuously according to such a continuous pyrolysis-in-batch
apparatus, each of the furnaces is still subjected to repeated
heating and cooling, as well as the loading and unloading of
batches. Furthermore, the individual operation of each furnace
makes the operation of the continuous pyrolysis-in-batch
apparatuses more complex. Moreover, such a continuous pyrolysis
apparatus that uses a plurality of pyrolysis furnaces is
necessarily huge and bulky in volume, and consequently limits its
use in application.
[0008] Accordingly, continuous pyrolysis furnaces that do not
require a plurality of parallel pyrolysis furnaces have been
developed recently. For example, a continuous pyrolysis apparatus
comprising a vertically arranged stirrer is disclosed in Taiwan
Patent Publication No. 361356. The stirrer has a stirring rod and
an auger conveyor disposed thereon to assist in stirring,
preheating, pyrolyzing the waste rubber and preventing occurrence
of the bridging phenomenon. However, this pyrolysis apparatus still
adopts a dry pyrolysis method which uses a dry gas, such as an
inert gas, to carry the resultant pyro-gas out. When using a dry
pyrolysis method, the pyrolysis furnace may explode due to a
significant amount of combustible oil gases generated during the
pyrolysis which is conducted at high temperature. Moreover,
sulfurous component(s) contained in waste tires will be released
during the pyrolysis of the waste tires. For a conventional
pyrolysis technology using an inert gas as the carrier gas, the
gaseous sulfurous component(s) will lead to a high sulfur content
in the resultant pyro-products according to Henry's Law, and the
quality of the products is thereby lowered.
[0009] In view of the disadvantages of conventional pyrolysis
apparatuses, a pyrolysis apparatus is provided in the present
invention, which allows for continuous pyrolysis without increasing
the number of pyrolysis furnaces and can prevent blocking and
bridging phenomena in the pyrolysis furnace. Furthermore, the
pyrolysis apparatus of the present invention allows for a
continuous pyrolysis reaction, belonging to a continuous pyrolysis
method, and eliminates the complex operational procedures of
heating up and cooling down the pyrolysis apparatus. Additionally,
the use of steam in the apparatus of the present invention can
reduce the likelihood of explosion caused by combustible oil gases
generated in the pyrolysis furnace, reduce the potential risks of
the pyrolysis apparatus, and effectively dissolve the sulfurous
component(s) into the steam and then carry the sulfurous
component(s) out with the steam to reduce the sulfur content in the
reaction products and the potential pollution extent on the
environment.
SUMMARY OF THE INVENTION
[0010] One objective of this invention is to provide a pyrolysis
furnace, which comprises a reaction chamber and one or more axial
transporting structures. The reaction chamber comprises a charge
opening and a discharge opening, and the one or more axial
transporting structures are installed in the reaction chamber. Each
of the transporting structures has a central axis, and comprises
one or more spiral segments and one or more paddle segments. The
total length of the paddle segments along the central axis
direction ranges from about 5% to about 35% of the length of the
transporting structure. This pyrolysis furnace can be applied to a
continuous steam pyrolysis apparatus to conduct a pyrolysis
reaction therein, and is especially suitable for recycling waste
tires through the pyrolysis process.
[0011] Another objective of this invention is to provide a
continuous steam pyrolysis apparatus, which comprises a heat
generator, a combustion chamber, and a superheated steam generator.
The combustion chamber communicates with the heat generator and has
a reaction chamber with one or more axial transporting structures
disposed therein. The reaction chamber comprises a charge opening
and a discharge opening. The one or more axial transporting
structures are installed in the reaction chamber. In addition, the
superheated steam generator communicates with the reaction chamber.
Each of the transporting structures has a central axis and
comprises one or more proceeding zones and one or more blending
zones. The total length of the blending zones along the central
axis direction ranges from about 5% to about 35% of the length of
the transporting structure.
[0012] The detailed technology and preferred embodiments
implemented for the subject invention are described in the
following paragraphs accompanying the appended drawings for people
with ordinary skill in this field to well appreciate the features
of the claimed invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a side view of an embodiment of a pyrolysis
furnace of the present invention;
[0014] FIG. 2 is a cross-sectional view of an embodiment of a
pyrolysis furnace of the present invention;
[0015] FIG. 3 is a partial enlarged view of the pyrolysis furnace
of FIG. 2;
[0016] FIG. 4 is a schematic view of a continuous steam pyrolysis
apparatus of this invention;
[0017] FIG. 5 is a side view of a superheated steam generator and a
pyrolysis furnace in a continuous steam pyrolysis apparatus of the
present invention; and
[0018] FIG. 6 is a schematic partial view illustrating how
materials pass through a pyrolysis furnace of the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] The pyrolysis furnace of the present invention comprises a
reaction chamber with a charge opening and a discharge opening, and
one or more axial transporting structures installed in the reaction
chamber. Each of the transporting structures has a central axis,
and comprises a plurality of spiral structures and a plurality of
paddle structure disposed along the central axis direction.
Accordingly, one or more spiral segments consisting of the screw
structures and one or more paddle segments consisting of the paddle
structures are formed. Each of the spiral/paddle structures has the
same or different spacing from neighboring spiral/paddle
structures. Preferably, each of the paddle segments is
substantially identical in length, and each of the spiral segments
is substantially identical in length. In an embodiment, each of the
transporting structures comprises a plurality of spiral segments
and a plurality of paddle segments that are alternately arranged
with each other.
[0020] The reaction chamber of the pyrolysis furnace is preferably
a tubular reactor, although it is not solely limited thereto. The
so-called "tubular reactor" generally refers to any appropriate
reactors in which a space for containing materials therein is
formed into a striped shape, like a tube. Hence, the materials that
are fed into the reaction chamber via the charge opening will
proceed through the transporting structures of the reaction chamber
along the central axis thereof while reacting in the reaction
chamber, and finally move out of the reaction chamber via the
discharge opening.
[0021] Because the transporting structure of the pyrolysis furnace
of the present invention comprises paddle segments, the material to
be pyrolyzed is stirred and blended in the paddle segments when
transported along the central axis of the transporting structure to
make the pyrolysis of the material in the reaction chamber more
homogeneous and complete. It has been found that for the
application of pyrolyzing waste tires, a too low proportion of the
paddle segments makes it unable to achieve a desired stirring and
blending effect. On the other hand, a too large proportion of the
paddle segments makes the reaction chamber to be blocked by twisted
steel wires in the waste tires. For this reason, the total length
of the paddle segments along the central axis direction is
typically controlled to range from about 5% to about 35% of the
length of the transporting structure. Preferably, the total length
of the paddle segments along the central axis direction ranges from
about 10% to about 30% of the length of the transporting
structure.
[0022] The transporting structure may be driven by any appropriate
driving means (e.g., an electric motor), while the rotational speed
of the screws of the transporting structure can be adjusted
depending on the needs (e.g., species, composition and size of the
material to be pyrolyzed) to control the resident time of the
material to be pyrolyzed in the reactor chamber.
[0023] Optionally, the reaction chamber may comprise a plurality of
reaction regions each comprising one transporting structure
described above and in communication with each other, so that the
material to be pyrolyzed can be transported among the reaction
regions. These reaction regions "communicate" with each other in
any appropriate forms. For example, the reaction regions may
communicate with each other through a pipeline, or may be disposed
adjacent to each other and communicate merely through the openings.
The arrangement of the plurality of reaction chambers can keep any
single transporting structure from overload while still achieving
complete pyrolysis. Alternatively, the reaction regions may be
arranged one above the other to make full use of the available
space.
[0024] The present invention further provides a continuous steam
pyrolysis apparatus, which comprises a heat generator, a combustion
chamber, and a superheated steam generator.
[0025] The heat generator is adapted to supply necessary heat for
the continuous steam pyrolysis apparatus. In one embodiment of this
invention, the heat is supplied in the form of a high-temperature
gas, which is obtained by combusting combustible gases recycled
from the pyrolysis process or fuel oil through the appropriate
equipment such as combustion furnaces. Preferably, the heat
generator is capable of utilizing the combustible gases recycled
from the pyrolysis process to conserve energy and save the running
cost.
[0026] The combustion chamber communicates with the heat generator
to receive heat supplied by the heat generator to perform a
pyrolysis reaction therein. The combustion chamber comprises a
reaction chamber and an axial transporting structure located in the
reaction chamber. In one embodiment, an appropriate pipeline is
used to introduce heat generated by the heat generator into the
combustion chamber to attain the necessary temperature for the
pyrolysis reaction in the reaction chamber. The material to be
pyrolyzed in the reaction chamber proceeds progressively and are
timely stirred and blended via the axial transporting structure to
achieve a uniform pyrolysis effect.
[0027] In conventional pyrolysis-in-batch techniques, products
resulting from the pyrolysis reaction must be taken out with
additional manpower or through machine operations, which is both
time- and labor-consuming. Moreover, because there is no effective
means to properly stir the material under reaction, conventional
pyrolysis-in-batch apparatuses often fail to achieve a uniform and
complete pyrolysis effect. In contrast with conventional
pyrolysis-in-batch apparatuses, the axial transporting structure
disposed in the reaction chamber of the pyrolysis apparatus of the
present invention comprises proceeding zones for moving the
material to be pyrolyzed forward during the reaction and also
blending zones for appropriately stirring the material to be
pyrolyzed while the material is moved forward, thereby the material
to be pyrolyzed being mixed more uniformly and pyrolyzed more
completely. Furthermore, with the transporting structure arranged
in the reaction chamber, the pyro-products can be transported out
of the reaction chamber for subsequent processing, thus remarkably
improving the performance of the apparatus and the economical
benefits.
[0028] In an embodiment of this invention, an axial transporting
structure with a plurality of spiral segments as the proceeding
zones and a plurality of paddle segments as the blending zones is
employed. Each of the spiral segments comprises one or more spiral
structures, and each of the paddle segments comprises one or more
paddle structures. Preferably, the spiral segments and the paddle
segments are alternately arranged with each other in an appropriate
ratio; i.e., the axial transporting structure comprises paddle
segments and spiral segments arranged alternately with each other.
Optionally, the ratio of the paddle segments to the spiral segments
can be adjusted. For the application of pyrolyzing waste tires, if
the blending segments are provided in a rather low percentage, it
would be impossible to obtain the desired stirring and blending
effect. On the other hand, if the blending segments are provided in
a rather high percentage, the reaction chamber will be easily
blocked by twisted steel wires in the waste tires. It has been
found that for the pyrolysis of waste tires, it is desirable for
the total length of the paddle segments to range from about 5% to
about 35% of the length of the transporting structure. Preferably,
the total length of the paddle segments ranges from about 10% to
about 30% of the length of the transporting structure. Therefore,
the pyrolysis furnace of the present invention can be used to
provide the reaction chamber and the axial transporting structure
necessary for the continuous pyrolysis apparatus, with the paddle
segments functioning as the blending zones and the spiral segments
functioning as the proceeding zones. The relevant structures and
equivalent modifications thereof are just as described above and
thus will not be described again herein.
[0029] The superheated steam generator communicates with the
reaction chamber of the combustion chamber to supply superheated
steam at a temperature of higher than 100.degree. C. as the carrier
gas of the gaseous pyro-products. The superheated steam generator
itself may be provided with a steam boiler for generating steam.
Steam thus generated is subsequently heated to form superheated
steam at a high temperature. The steam can be heated in any
appropriate manner, for example, by means of electric heating, fuel
combustion, or a high-temperature gas. Alternatively, a superheated
steam generator without a steam generating device may be used; in
this case, in addition to communicating with the reaction chamber
of the combustion chamber, the superheated steam generator further
communicates with an external steam source to heat the steam
transferred therefrom to form superheated steam.
[0030] To make an efficient use of the energy source, the
superheated steam generator or portions of the superheated steam
generator which transforms the steam into superheated steam can be
optionally installed inside the combustion chamber along with the
reactor to utilize heat from the heat generator more efficiently.
In an embodiment of this invention, the superheated steam generator
is designed into a tubular structure surrounding the outer wall of
the combustion chamber. One end of the tubular structure is
connected with the reaction chamber while the other end thereof is
connected with a steam source. The heat supplied by the heat
generator, while heating the reaction chamber, will also heat the
superheated steam generator to supply superheated steam without any
additional heating devices. Thus, the high-temperature gas from the
heat generator heats the reaction chamber and the superheated steam
generator of the combustion chamber at the same time to provide the
desired temperature necessary for the pyrolysis reaction and supply
superheated steam.
[0031] The aforesaid steam source may come from a steam generator,
which may be a steam boiler of any appropriate type (e.g., an
electric heating type, a combustion type, or a vacuo heating type),
or may come from steam generated by other processes. Additionally,
the steam generator may be provided with or without a combustor.
For embodiments in which the steam generator does not have a
combustor, the steam generator communicates with the combustion
chamber, so that the wasted heat from the reaction chamber (and the
superheated steam generator) is introduced into the steam generator
to heat water to form steam. Alternatively, heat supplied by the
heat generator may be used directly to generate steam. Moreover,
for embodiments in which a steam generator with a combustor is
used, the necessary heat for steam generation may be supplied by
the combustion of fuel oils and/or combustible gases recycled from
the pyrolysis reaction.
[0032] Depending on the material to be pyrolyzed, various gaseous,
liquid and/or solid products may be generated from the pyrolysis
reaction. To effectively recycle these pyro-products, the
continuous steam pyrolysis apparatus of the present invention may
optionally further comprise one or more separating devices. For
instance, when the apparatus is used to treat waste tires, the
pyro-products may include gaseous oil-gas products such as
pyro-oils, combustible gases and water as well as solid-material
products such as steel wires and carbon black. Hence, the
pyro-oil-gas processing system and/or a pyro-solid-material
processing system can be further included at the downstream of the
continuous steam pyrolysis apparatus of this invention.
[0033] The pyro-oil-gas processing system is generally adopted to
treat gaseous products from the reaction chamber, and may comprise
a purifying device for removing the solid impurities possibly
entrained in the oil-gas, a condensing device for cooling down the
oil-gas, an oil-water separating device for separating water from
the condensed liquid, and/or a waste water processing device for
further processing the separated water. Of course, the pyro-oil-gas
processing system may optionally comprise other separating
devices.
[0034] The purifying device, if used, usually communicates with the
reaction chamber to remove dusts/particles (e.g., carbon black
particles) possibly generated during the pyrolysis reaction. In an
embodiment, a high-temperature filtering device with a pulse
backwash capability is used as a purifying device. The
high-temperature filtering device is usually provided with a
filtering element (e.g., a metal mesh or a ceramic filtering
cartridge) to remove the dusts/particles. The principles and
technologies of "pulse backwash" are well-known to those with
ordinary skill in the art and thus will not be further described
herein. The filtering performance of filtering devices without the
backwash capability, such as a powerful downdraft filtering device,
usually degrades with continued operation of the devices. This is
because the mesh is blocked by excessive particles or dusts
filtered out from the gases. In contrast, the filtering device with
the backwash capability may avoid the blocking phenomenon
effectively to ensure a continuous reaction. When a filtering
device with the pulse backwash capability is used, the superheated
steam generator may be allowed to communicate with the
high-temperature filtering device to intermittently supply the
high-temperature filtering device with superheated steam.
Alternatively, combustible gases obtained from a subsequent
procedure of separating pyro-oil-gas may be fed back into the
high-temperature filtering device to accomplish the pulse backwash
action and to maintain a constant flow rate across the mesh.
[0035] The condensing device cools the gaseous components in the
pyro-products by means of condensation to separate the
pyro-products into pyro-oil, water, combustible gases and the like.
Any appropriate condensing device may be optionally used.
Generally, one or more condensers connected in series are used to
separate the pyro-products into a plurality of components for
subsequent use. In an embodiment, the condensing device consists of
two condensers connected in series is used and is disposed at the
downstream of the purifying device. This will ensure that the
particles and dusts contained in the gaseous components are
filtered out by the purifying device instead of entering the
condensing device, which would otherwise cause the blocking of the
apparatus or affect the economic value of the separated
products.
[0036] Due to the higher condensing temperature of oils, the oils
tend to be separated first from the separating device when
processing the pyro-oil-gas. To prevent the condenser from being
blocked due to the high viscosity of the condensed oils, a U-type
pipeline is preferably used at the front end of the condensing
device, so that the cooling water passes within the pipeline and
the gaseous components to be condensed passes through the outer
side of the U-type pipeline. In this way, the condensed oils will
drip naturally at the bottom of the condenser and be transferred to
the outside. Compared to the conventional condensing approach in
which the material to be condensed flows within the pipeline while
the cooling water passes outside the pipeline, this method can
effectively prevent the possible blocking by oils and ensure the
continuous operation of the apparatus.
[0037] The pyro-solid-material processing system may optionally
comprise various appropriate physically/chemically separating
devices. Generally, the pyro-solid-material processing system
comprises a separating device (e.g., a sorting machine or a
magnetic separator) and a crushing device (e.g., a grinding
machine) for further processing the solid pyro-products. When
treating waste tires, for example, the pyro-solid-material
processing system comprises a sorting machine, a magnetic separator
and a grinding machine. The sorting machine communicates with the
reaction chamber to preliminarily remove steel wires in the waste
tires from the solid pyro-products. The solid pyro-products that
have been treated to preliminarily remove steel wires then are
transported through the magnetic separator to further separate the
residual steel wires and other metal substances. Finally, the final
products are ground by the grinding machine into a desired particle
size for recycling. Additionally, a sorting apparatus may be
optionally provided at the downstream of the grinding machine to
further sort the ground products.
[0038] The pyrolysis furnace and the continuous steam pyrolysis
apparatus of the present invention may be used to pyrolyze various
materials such as waste tires, waste plastics, waste wood, or
agricultural biomass, and is preferably used to treat waste
tires.
[0039] To explain this invention more clearly, an exemplary
embodiment of the pyrolysis furnace and the continuous steam
pyrolysis apparatus of the present invention, which may be used to
treat waste tires, will be described hereinafter with reference to
the attached drawings. In the attached drawings, the dimensions of
individual elements are only provided for reference, but not for
reflecting the actual dimensional scale.
[0040] As shown in FIG. 1, a schematic view of a pyrolysis furnace
1 is depicted therein. The pyrolysis furnace 1 comprises a reaction
chamber 11, a driving device 13, a charge opening 151, a discharge
opening 153, a pyro-oil-gas outlet 155, a secondary-refining inlet
157, and a communicating opening 17. The reaction chamber 11
comprises a first reaction region 113 and a second reaction region
115 installed one above the other and communicating with each other
through the communicating opening 17. FIG. 2 illustrates a
cross-sectional view of the pyrolysis furnace 1 shown in FIG. 1.
Each of the first and the second reaction regions 113, 115 of the
reaction chamber 11 has one axial transporting structure 21
therein, and each of the axial transporting structure 21 is
connected to the corresponding driving device 13. Each of the
transporting structure 21 has a central axis 211 and comprises a
plurality of spiral segments 213 and a plurality of paddle segments
215. FIG. 3 depicts a partially enlarged view of the first and the
second reaction regions 113, 115, where L2 represents the length of
a single spiral segment and L3 represents the length of a single
paddle segment. The total lengths of the spiral segments 213 and
the paddle segments 215 are respectively calculated by summing the
length of each segment occupied along the direction of the central
axis 211. Generally, the sum of the lengths (L3) of the paddle
segments of a single transporting structure 21 is controlled to
range from about 5% to about 35% of the length of the transporting
structure 21.
[0041] Waste tires are fed through the charge opening 151 into the
reaction chamber 11 and pyrolyzed therein. The pyro-oil-gas
resulting from the pyrolysis reaction is fed out through the
pyro-oil-gas outlet 155, while the pyro-solid-material products are
fed out through the discharge opening 153. The waste tires are
firstly fed into the first reaction region 113 of the reaction
chamber 11 and moved forward gradually along the central axis of
the transporting structure 21 during the pyrolysis reaction by the
rotating transporting structure 21. In this course, the waste tires
stay temporarily in the paddle segments 215 to be stirred and
blended by the rotating paddles of the paddle segments. Because the
first and the second reaction regions 113, 115 are installed one
above the other, the waste tires under the pyrolysis reaction will
drop into the second reaction region 115 when reaching the
communicating opening 17 and then, with the rotation of the
transporting structure 21 of the second reaction region 115, be
moved forward to proceed with the pyrolysis reaction. The
pyro-solid-material products are fed out through the discharge
opening 153, while the pyro-oil-gas resulting from the pyrolysis
reaction is fed out through the pyro-oil-gas outlet 155.
[0042] FIG. 4 is a schematic view illustrating the arrangement of
an embodiment of a continuous steam pyrolysis apparatus of the
present invention. The continuous steam pyrolysis apparatus
primarily comprises a combustion chamber 31, a combustion furnace
33 and a steam boiler 39. As shown in FIG. 5, the pyrolysis furnace
1 as shown in FIG. 1 is disposed in the combustion chamber 31,
while a tubular superheated steam generator 311 surrounds the
reaction chamber 11 of the pyrolysis furnace 1.
[0043] Hereinafter, the pyro-oil-gas processing system used for
processing the pyro-oil-gas generated in the combustion chamber 31
will be described. As shown in FIG. 4, the pyro-oil-gas processing
system comprises a high-temperature filtering device 351, a
condensing device consisted of a first and a second condenser 352a,
352b, an oil-water separating tank 357, a gas stabilizing tank 355
and a waste water processing device 359. The combustion chamber 31
has a pyro-oil-gas outlet 155 and a first hot air outlet P19,
wherein the outlet 155 communicates with the pyro-oil-gas inlet P1
of the high-temperature filtering device 351 and the outlet P19
communicates with a second hot air inlet P20 of the steam boiler
39. In addition to the pyro-oil-gas inlet P1, the high-temperature
filtering device 351 further comprises an oil-gas outlet P2 and a
backwash air inlet P25, wherein the outlet P2 communicates with the
first condensation inlet P3 of a first condenser 352a. The inlet
P25 of this embodiment is adapted to guide the superheated steam
generated by the superheated steam generator 311 into the
high-temperature filtering device 351. In addition to the first
condensation inlet P3, the first condenser 352a further comprises a
first liquid inlet P4 and a first air outlet P5 communicating with
the oil tank opening P9 of an oil tank 353 and a second
condensation inlet P6 of a second condenser 352b respectively. In
addition to the second condensation inlet P6, the second condenser
352b further comprises a second liquid outlet P7 and a second gas
outlet P8 communicating with a second liquid inlet P10 of the
oil-gas separating tank 357 and a second gas inlet P11 of a gas
stabilizing tank 355 respectively. In addition to the second gas
inlet P11, the gas stabilizing tank 355 further comprises a
combustible gas outlet P15 communicating with a fuel inlet P16 of
the combustor 33. Optionally, the outlet P15 may further
communicate with the backwash gas inlet P25 (not shown).
[0044] In addition to the fuel inlet P16, the combustion furnace 33
further comprises an air outlet P17 communicating with the first
hot air inlet P18 of the combustion chamber 31. In addition to the
second liquid inlet P10, the oil-water separating tank 357 further
comprises an oil outlet P12 and a water outlet P13 communicating
with the oil tank opening P9 of the oil tank 353 and the waste
water inlet P14 of the waste water processing device 359
respectively.
[0045] In the embodiment of the steam pyrolysis apparatus, the
pyro-solid-material processing system is further included to treat
solid products generated in the reaction chamber 11. As shown in
FIG. 4, the pyro-solid-material processing system comprises a
sorting machine 371, a magnetic separator 373, a first bag-type
collector 377a and a second bag-type collector 377b. The sorting
machine 371 comprises a primary processing inlet P27, a primary
process gas outlet P28 and a primary solid product outlet P29. The
inlet P27 communicates with the discharge opening 153 of the
reaction chamber 11 to receive solid-material products generated in
the reactor 11, and communicates with the hot air inlet P22 of the
second bag-type collector 377b and a secondary processing inlet P30
of the magnetic separator 373 via the outlets P28 and P29
respectively. The magnetic separator 373 further comprises a
secondary processing outlet P31 that communicates with a tertiary
processing inlet P32 of the grinding machine 375. The grinding
machine 375 further communicates with the filtering inlet P34 of
the first bag-type collector 377a via a tertiary processing outlet
P33.
[0046] In addition to the third hot air inlet P22, the second bag
collector 377b further comprises a third hot air outlet P23
communicating with the waste gas inlet P26 of a waste gas
processing device 379. Meanwhile, the steam boiler 39 communicates
with the third hot air inlet P22 of the second bag-type collector
377b via a second hot air outlet P21 and communicates with the
superheated steam generator 311 via a steam outlet P24.
[0047] Hereinafter, the process in which steam pyrolysis apparatus
illustrated above treats waste tires will be explained. Optionally,
prior to the pyrolysis process, a pre-processing device such as a
crusher or a cutting machine is used to pre-process the waste tires
into an appropriate size. Then, the waste tire granules with the
appropriate size (usually cut into a particle size from about 5 cm
to about 7 cm) are fed into the reaction chamber 11 of the
pyrolysis furnace 1 via the charge opening 151 with a speed of
about 1000 kg/hour. At this point, the temperature outside the
pyrolysis furnace 1 is kept between about 700.degree. C. and about
1000.degree. C. to heat the superheated steam generator 311 and
keep the temperature of the reaction chamber 11 between about
350.degree. C. and about 550.degree. C., and preferably between
about 350.degree. C. and about 480.degree. C. Meanwhile, the
superheated steam generated by the superheated steam generator 311
is introduced into the reaction chamber 11 to participate in the
pyrolysis reaction.
[0048] The waste tire granules are transported by the transporting
structure 21 and pass through the proceeding zones and the blending
zones alternately (i.e., pass through the spiral segments 213 and
the paddle segments 215 alternately) in the reaction chamber 11 to
be pyrolyzed completely. FIG. 6 illustrates how a material 22 to be
pyrolyzed (e.g., waste tire granules) passes through the first
reaction region 113 of the reaction chamber 11. More specifically,
the material 22 is moved forward in one spiral segments 213 and
accumulates gradually, and is then stirred and blended upon
reaching one paddle segments 215, after which the material 22
gradually falls into a next spiral segment 213 and keeps moving
forward. When the material is transported to the end of the first
reaction region 113, a residual carbon black mixture and
un-pyrolyzed waste tire granules fall into the second reaction
region 115 via the communicating opening 17 to proceed with the
pyrolysis. The material passes through the second reaction region
115 in substantially the same way as that in the first reaction
region 113. During the pyrolysis, oil-gas resulting from the
pyrolysis reaction is transported to the pyro-oil-gas processing
system, and the non-gaseous pyro-products are either transported to
the pyro-solid-material processing system or, optionally, fed into
the second reaction region 115 via the secondary refining inlet 157
for secondary refining. In more detail, the pyro-oil-gas flows into
the high-temperature filtering device 351 where carbon black
particles therein are removed through, for example, a
high-temperature steam pulse backwash process. Generally speaking,
a high-temperature filtering device 351 equipped with a porous
ceramic cartridge or a metal mesh may be employed, wherein the
operation temperature is controlled to range from about 280.degree.
C. to about 450.degree. C. and the filtering rate is controlled to
range from 1 cm/second to 3 cm/second.
[0049] Subsequently, the pyro-oil-gas that the carbon black has
been removed is subjected to a condensing process, which is usually
a two-stage condensing process. In particular, as shown in FIG. 4,
the pyro-oil-gas is introduced into the first condenser 352a first
to cool down the pyro-oil-gas to a temperature of about 110.degree.
C. The condensed oils thus obtained may be processed in a
subsequent process for recycling, so that the residual pyro-oil-gas
proceeds to the second condenser 352b where it is cooled down to a
temperature of about 40.degree. C. The condensed oils thus
separated may also be processed in a subsequent process for
recycling, and the condensed water is optionally subjected to a
waste water treatment process for recycling or disposal. The
condensed pyro-gases may also be optionally subjected to a gas
stabilizing process, and then fed into the combustion furnace 33 to
further supply the necessary heat for use in this invention.
[0050] In the case of pyrolysis waste tires, the material to be
pyrolyzed usually comprises metal pieces such as steel wires, and
therefore a sorting process may be carried out first on the
pyro-products resulting from the reaction. For example, non-gaseous
pyro-materials from the pyrolysis may be transported to the sorting
machine 371 to preliminarily remove the steel wires and carbon
black and cool down the pyro-solid material (generally cooled down
to a temperature lower than 100.degree. C.). In this step, the
residual gaseous components in the pyro-materials are fed into the
second bag-type collector 377b to remove carbon black particles,
and are subsequently processed by the waste gas processing device
379 for emission. The pyro-solid materials with the steel wires are
removed preliminarily and are subsequently transported to the
magnetic separator 373 to further remove the steel wires and carbon
black. The carbon black collected is subsequently ground to the
desired particle size. The carbon black is usually ground to a
particle size capable of passing through a screen sized 200 mesh to
be recycled.
[0051] In this embodiment, diesel oil or fuel oil is used as the
fuel of the combustion furnace 33 at the early stage of the
operation, and upon commencement of the pyrolysis reaction,
combustible gases resulting from the pyrolysis reaction may be used
as a fuel to reduce the cost. Here, the fuel has a flow rate of
about 80 liters/hour. A high-temperature gas generated by the
combustion furnace 33 is introduced into the combustion chamber 31
through, for example, fan drafting. The high-temperature gas
maintains the temperature inside the combustion chamber 31 within a
range of about 700.degree. C. to about 1000.degree. C., and heats
the pyrolysis furnace 1 and the superheated steam generator 311 to
obtain a temperature necessary for the pyrolysis reaction (about
350.degree. C. to about 550.degree. C.) in the reaction chamber 11
of the pyrolysis furnace 1. The high-temperature gas within the
combustion chamber 31 may then be transferred to the steam boiler
39 to heat water to form steam. In this respect, this invention
does not preclude the use of a steam boiler 39 equipped with a
combustor in itself. In other words, the steam boiler 39 may be
heated by the high-temperature gas from the combustion chamber 31,
the hot air generated in the combustion furnace 33, and/or the
other combustor equipped in the steam boiler 39 itself to generate
steam. Likewise, the combustor in the steam boiler 39 may also
utilize combustible gases resulting from the pyrolysis reaction as
a fuel to reduce the costs.
[0052] On the other hand, steam generated in the steam boiler 39 is
used by the superheated steam generator 311 to generate superheated
steam, and may also be used by the high-temperature filtering
device 351 to execute a steam pulse backwash process to remove
undesired particles. In more detail, a portion of the steam
generated in the steam boiler 39 is transferred to the superheated
steam generator 311 via the steam outlet P24, and then flows
forward in the superheated steam generator 311 where it is heated
by the high-temperature gas in the combustion chamber 31 to finally
form superheated steam. A portion of the superheated steam is
introduced into the reaction chamber 11 for use as a carrier gas in
the pyrolysis reaction, while another portion of the superheated
steam is introduced into the high-temperature filtering device 351
via the backwash gas inlet P25 for pulse backwashing on a regular
or irregular basis, thereby effectively preventing the blocking of
the device. Here, as previously described, stabilized combustible
gases from the gas stabilizing tank 355 may also be fed into the
high-temperature filtering device 351 via the backwash gas inlet
P25 to conduct a pulse backwash process. Accordingly, the
superheated steam and combustible gases may be used in combination
depending on the arrangement and conditions of energy
sources/materials in the whole apparatus. For example, the
superheated steam from the superheated steam generator 311 and the
combustible gases from the gas stabilizing tank 355 may be used
alternately.
[0053] In summary, the pyrolysis furnace of the present invention
is unique in that the transporting structure thereof has paddle
segments serving as blending zones which ranges from about 5% to
about 35% of the transporting structure in length. This percentage,
a result obtained from numerous tests by the inventors, not only
prevents the incomplete pyrolysis due to insufficient stirring when
only spiral structures are used, but also prevents the blocking of
the apparatus (e.g., twisting of steel wires in the waste tires)
due to a high percentage of paddle structures.
[0054] Furthermore, in addition to the aforesaid pyrolysis furnace,
the continuous steam pyrolysis apparatus of the present invention
may further comprise a purifying device and/or a condenser designed
with a U-type pipeline. The purifying device is adapted to remove
particles (e.g., carbon black particles) from the pyro-gases, which
helps to improve the quality of resultant oils, prevent the
blocking of a condensing device at the downstream thereof, and
reduce the cost of a subsequent oil refining process. Also, the
particles (e.g., carbon black particles) thus collected deliver
better economic outcomes. Moreover, in the condenser with a U-type
pipeline design used in this invention, the cooling water flows
within the pipeline, while the pyro-oil-gas flows along the outer
side of the pipeline to prevent blocking.
[0055] Furthermore, the continuous steam pyrolysis apparatus of
this invention utilizes superheated steam as the carrier gas. The
use of the steam can prevent an explosion that would likely occur
in conventional dry-type pyrolysis processes. On the other hand,
the steam can decrease the sulfur content in the pyro-products and
ensure a better economic value thereof.
[0056] Due to these advantages, the apparatus of the present
invention is capable of efficiently pyrolyzing materials,
especially waste tires, on a continuous basis, and the products
thus obtained have better economic values.
[0057] The above disclosure is related to the detailed technical
contents and inventive features thereof. People with ordinary skill
in this field may proceed with a variety of modifications and
replacements based on the disclosures and suggestions of the
invention as described without departing from the characteristics
thereof. Nevertheless, although such modifications and replacements
are not fully disclosed in the above descriptions, they have
substantially been covered in the following claims as appended.
* * * * *