U.S. patent application number 10/534564 was filed with the patent office on 2006-06-01 for modular infrared irradiation apparatus and its corresponding monitoring devices.
Invention is credited to Rangel Paulo Gerais De Camargo.
Application Number | 20060115778 10/534564 |
Document ID | / |
Family ID | 32303990 |
Filed Date | 2006-06-01 |
United States Patent
Application |
20060115778 |
Kind Code |
A1 |
Camargo; Rangel Paulo Gerais
De |
June 1, 2006 |
Modular infrared irradiation apparatus and its corresponding
monitoring devices
Abstract
Heat irradiation apparatus (1) defined in terms of the
following:--Refractory flexible irradiation module (7) comprising
stopping means which are high temperature resistant and avoid
shadow zones and side losses of heat at the burning zone in the
ceramic surface;--Employment of refractory flexible ceramic plates
(15) having flexible pores which permit air/gas modulation, the
flexible pores permit define the path of the air/gas mixture
through the ceramic plate (15). When the flow pressure of mixture
is reduced, part of the pore automatically close and the
combustible mixture is conducted to the surface where the hot
fibers are placed. The fibres keep the combustion active at the
surface, multiplying IR heating effects. Ceramic plates (15) of the
art tend to "swallow" the flame causing an inner burning and
reducing the efficiency of the process and/or loss of the control
of the flame and equipment explosion.--Sensors and measuring means
are provided for monitoring all steps: Thermal sensor (14)--safety
device applied in the lower face of each flexible fibrous ceramic
module (15), more particularly fixed in the support screen of the
ceramic plate (15) and extending to median line of such plate (15),
for monitoring a possible heat flow inversion due to external
factors which cause the "flame swallowing". The apparatus further
comprises oxygen measuring means (23) and an ultraviolet flame
detector (24).
Inventors: |
Camargo; Rangel Paulo Gerais
De; (Valinhos Sp, BR) |
Correspondence
Address: |
LUCAS & MERCANTI, LLP
475 PARK AVENUE SOUTH
15TH FLOOR
NEW YORK
NY
10016
US
|
Family ID: |
32303990 |
Appl. No.: |
10/534564 |
Filed: |
November 7, 2003 |
PCT Filed: |
November 7, 2003 |
PCT NO: |
PCT/BR03/00159 |
371 Date: |
May 9, 2005 |
Current U.S.
Class: |
431/79 ; 431/154;
431/328 |
Current CPC
Class: |
H05B 3/0038 20130101;
F23D 14/16 20130101; F23D 2203/105 20130101; F26B 3/305 20130101;
F23D 2212/103 20130101; H05B 2203/032 20130101; F23N 5/08 20130101;
D21F 5/002 20130101 |
Class at
Publication: |
431/079 ;
431/328; 431/154 |
International
Class: |
F23N 5/08 20060101
F23N005/08; F23D 14/12 20060101 F23D014/12 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 8, 2002 |
BR |
BR-PI-0204969-4 |
Claims
1- MODULAR INFRARED IRRADIATION APPARATUS AND ITS CORRESPONDING
MONITORING DEVICES, the modular IR irradiation apparatus (1), more
particularly directed to heat tranfer at elevated rates to a
receiving substrate (L), as in industrial drying steps of paper and
cellulose production; the modular IR irradiation apparatus (1)
comprises a metallic frame or bed (2), which is designed to receive
a number of irradiation modules (7), contaning primary plenum (3p)
and secondary plenum (3s) distribution ducts which contain feeding
outlet (3a) for the mixture of combustible gas and air (G) to the
modules (7); characterized in that the modular IR irradiation
apparatus (1) comprises: Mounting means which is explosion proof
and blocks the bed (2) by means of side lower (LI) and upper (LS)
metallic plates arranged in a laminar portion having angular flaps
(18) fixed in side closing mirrors (19) and having further closing
of bottom caps (6) having side flaps (6a) and closing flaps (22 and
P1) and being engaged in an longitidunal latche (22) in the flap
(18) of the lower plate (LI); the blind mirror (EC) and the
instrument mirror (EI) having holes which are fitted to te devices
to be fixed thereto; Constructing means for fixing the irradiation
element (1) to the process via support tube (4) and locking bearing
(M); Constructing means for housing, feeding, and combustible gas
(G) distribution in the flexible refratory ceramic (15) modules (7)
mounted transversally to the cavity (CR) of the bed (2); Mechanical
means of pressurized sealing air admission (AS) in the mirror (EI)
of the bed (2), pressurization of the inner cavity of the
equipment, cooling the UV system and provide a venturi effect of
the oxygen measuring means; Constructing means for side mouting and
sealing (17) of the flexfveis refratoric ceramic (15) of the
modules (7) and fixation of the ceramic thin housings (16) with
elastomer (17); The flexible refractory ceramic (15) is maleable
and have a porous feature related to the fibrous mass; Monitoring
device of the thermal flow direction of the modules (7) by using
sensors (14); Collecting and monitoring device of the smokes from
the surface burning (D1) of the modules (7) by using oxygen
measuring means (23) based on Zirconinum oxide; UV flame detection
device (24) applied in th tube (4) positioned to the cavity (CR)
and the surface (D1).
2- Apparatus, according to claim 1, characterized in that the
metallic sides (LS) are provided with alleviating and dilatation
channels (AD).
3- Apparatus, according to any one of claims 1 or 2, characterized
in that each irradiation module (7) comprises a base receiver (8)
having a feeding hole (11), each module (7) is fixed to the plena
(3p, 3s) by means of screws and pins (P); the referred base (8)
receives at its free edge a screen (12) having holes (12a) and in
which lower face are fixed at least two set of thermal flow sensors
(14) interconnected by the electronic circuit (13); such sensors
(14) are interconnected to an electronic device (14a) which is
connected to the LPC central; at the upper face of the referred
screen (12) is positioned a porous flexible refractory ceramic
plate (15) and its respective fixing means, side sealing (17) (S)
in which lower median portion the sensors (14) are kept.
4- Apparatus, according to claim 1, characterized in that the bed
(2) internally receives rectangular support and distribution ducts,
a primary plenum (3p) a secondary plenum (3s) which possesses a
feeding tube (10) and outlets (3a) for feeding the modules (7) with
combustible gas/air mixture (G) such ducts are aligned to holes (9)
existing in each one of modules (7) directed to the secondary
plenum (3s) or via modulation or blocking valve (VL) to the primary
plenum (3p).
5- Apparatus, according to claim 4, characterized in that the
feeding hole (9) of each module (7) is positioned in relation to
the surface called base (8).
6- Apparatus, according to any one of the preceding claims,
characterized in that the modules (7) can be coupled via feeding
hole (9) to the primary plenum (3p) or to the secondary plenum (3s)
by a 180.degree. rotation position inversion of each module
(7).
7- Apparatus, according to any one of the preceding claims,
characterized in that the modules can de framed in variable lenghts
and widths.
8- Apparatus, according to claim 3, characterized in that holes
(12a) of th screen (12) have circular dimensions or other suited
dimensions.
9- Apparatus, according to claim 3 characterized in that thermal
flow sensors (14) overpass the screen (12) until effect a deep
contatct to the ceramic (15) where the sensors are fixed in one
position under the line (Y).
10- Apparatus, according to any one of the preceding claims,
characterized in that the side stopping means (S) of each plate of
flexible refractory ceramic are arranged for fit in thin ceramic
housings (16) anchored at the side faces of the ceramic plate by an
elastomer layer (17) which is able to penetrate in both parts (15,
16).
11- Apparatus, according to claim 10, characterized in that the
sealing means (S) serves as anchoring means adhering to the parts
(15, 16) and avoiding side dispersion (D) of the combustible
gas/air mixture (G) entering in the ceramic plate (15). via screen
holes (12a).
12- Apparatus, according to claims 10 and 11, characterized in that
the sealing means (S) of each one of ceramic plate (15) avoid a
side burning zone (D) keeping the burning zone restricted to the
face (D1) existing at the surface of the ceramic plate (15).
13- Apparatus, according do claim 11, characterized in that block
comprising the flexible refractory plate (15) and the thin ceramic
housings (16) are fixed to the screen and to the base (8) by
applying an elastomer layer (17) producing a flexible sealed
junction which supports natural vibrations.
14- Apparatus, according to any one of the preceding claims,
characterized in that the elatomer (17) is high temperatures
resistant.
15- Apparatus, according to any one of the preceding claims,
characterized in that the refractory ceramic plate is flexible and
porous.
16- Apparatus, according to claim 15, characterized in that the
fiber fabric (F) of the ceramic plate (15) is kept free for
movements (V) which can occur due to the forced passage of gas (G),
permitting the movement for distribution of gas flow through the
pores (R) of the fibrous estruture.
17- Apparatus, according to claims 15 or 16, characterized in that
the porous flexible refractory ceramic plate (15) permits
modulation of the gas volume (G) and the emission power of the
irradiation apparatus (1) keeping the rate of discharge in the
active pores compatible with the combustion rate and keeping the
emission temperature and the flame position stable at the first
layers (D1) of the ceramic plate (15).
18- Apparatus, according to any one of preceding claims,
characterized in that the thermal flow sensor (14) is able to
monitoring the thermal flow inversion at the ceramic plate (15),
and keeping a maximum temperature differential at de median line
(Y) in each ceramic plate.
19- Apparatus, according to claim 18, characterized in that the
sensors (14) are verified by the LPC which is the responsible for
the temperature differential monitoring in each plate (15) and
generates a gas bloclking alarms.
20- Apparatus, according to any one of the preceding claims,
characterized in that the oxygen measuring means (23) comprises a
Zirconinum oxide based sensor (25) which is applied near to the
burning zone (D1) and is able to monitoring and analyzing the
amount of residual oxygen after the combustible burning; the sensor
is connected to the LPC of the monitoring system.
21- Apparatus, according to claim 20, characterized in that the
oxygen measuring means (23) comprises a device having a temperature
controlled chamber (26) formed by five tubular bodies (27, 28, 30,
31, 33) which are welded (29) one to the other, the set (23) is
fixed by holders (34) at the side upper internal flap (LI), the
tubular body (28) is fixed in one extension (31) which is able to
form a venturi system joined the tubular body (30), the tube (30)
have the greates diameter for conduct the pressurized sealing air
from the bed (2) to outside, a collecting tip (35) is coupled to
the upper edge of the tube (33) and it is provided with holes (36)
at the lower position and with concentrating flaps (37).
22- Apparatus, according to claims 20 and 21, characterized in that
the collecting tip (35) is used by the differential lighting system
as ground contact for discharge the trigger.
23- Apparatus, according to any one of the preceding claims,
characterized in that the UV flame detector (24) comprises an UV
bulb sensor (39) encapsulated and protected (38) inside the cooling
device (40) which extends to the collimation cavity of IR emission
(CR) via ceramic tube (47); the UV sensors (24) are positioned at
the external side of the instrument mirror (EI), more particularly
fixed at the supports (44) by means of tubes (48) which serve to
conduct pressurized sealing air inside the irradiation support tube
(4) to the cooling body (40); the cooling body (40) comprises flaps
(41) at its external face defining cooling channels for keeping the
inner chamber (42) of the sensor housing (39) cool; such body also
comprises an lower hole (43) coupled to the metallic box type
support (44) through which the cooling air is conducted and the
wires connecting the electronic monitoring part (flame relay); the
ceramic protection tube (47), is fixed to the cooling body (40) to
the flange (45) which possesses inner tips as retention means (46)
of such tube (47).
24- Apparatus, according to claim 23, characterized in that the UV
flame detector (24) can be double mounted and being placed two
flame detectors (24) to a single irradiation apparatus (1).
25- Apparatus, according to claims 23 and 24, characterized in that
the ceramic tube (47) restrains and protect the sight field of the
bulb (39) against obstructions caused by vapor clouds from the
process.
Description
FIELD OF THE INVENTION
[0001] The present invention refers to a modular infrared
irradiation apparatus which employs combustion gas and its
respective monitoring devices. Particularly, the apparatus of the
present invention is direcetd to thermal transfer operations for
provide quick and efficient thermal energy transfers at high rates
as in industrial drying operations of paper making and cellulose
industries. The irradiation apparatus comprises automation means
for control the starting and all steps of the procedure which is
performed by such equipment and permits multiple industrial
applications.
BACKGROUND OF THE INVENTION
[0002] Technicians of the art, particularly those skilled in the
continous fibrous products manufacturing processes, know that a
drying step (or a set drying steps distributed along the process)
is a necessary step for drying coating or impregnating substances
added to the product.
[0003] Known drying techniques employ heat transfer by direct
contact between the heat receiver and the planar and/or cylindrical
heat source or by means of hot air blowing.
[0004] The Infrared (IR) drying technique is the most preferred
because the direct contact step for heat transfer is avoided. Thus,
this embodiment normally employed for complementary drying
applications in the traditional drying steps of the art.
[0005] For each konwn different drying step, the desired result,
e.g., substrate features, and surface and phisical properties, may
differ. Therefore, in view of the above, a refined techinique,
derived from known embodiments, which is complemented by IR drying
step is seen as the best result maker.
[0006] Recently, the use of an IR drying process has been seen as
the best alternative because such techinique is suited to several
industrial applications and for provide solutions for old problems
of the art.
[0007] The IR technique has particular features and such features
make the difference when applied to known heat irradiation
apparatus of the art. The IR generation techniques are basically
distinguished in the temperature average and in the frequence range
of the irradiating element.
[0008] In the heat irradiation apparatus production, the selection
of building materials determines the IR emission ability of such
apparatus in some ranges of frequence, i.e., metallic irradiation
elements generate long and medium waves. Ceramic irradiation
elements at high temperatures generate short and medium waves.
Generally, short waves have best penetration features in substrates
in relation to long waves, and it permits that a substrate be dried
without direct contact and avoinding damage to the dried substrate
surface.
[0009] The eletromagnetic energy produced at IR frequence bands, if
correctly set, will be absorved by substrate in such manner that
the material will change, firstly in its initial state by absorbing
heat and modifying its temperature. For volatile substances like
water, the absorbed heat permits the chance of phisical state, from
liquid to vapor, and thus the drying step occurs by evaporating all
volatile mass contained in the substrate.
[0010] The amount of water to be evaporated from the substrate is a
particular feature of the product and depends on the manfacturing
route and the final application of such product. Therefore the
intensity of thermal energy in each case is to be particularly
determined.
[0011] IR use as a final controller of remaining volatiles in the
substrate, e.g., the substrate humidity, is an alternative that
depends of the irradiation element. If the element is able (or not)
to change the heat emission power the process is able to dry the
substract at the desired level.
[0012] Several types of irradiation models as mentioned above are
known in the art. Most of them comprise a metallic frame which
enclose irradiation elements into metal housings, such elements are
installed side by side transversally or alongside of the process
direction. The irradiation elements are positioned near to the
substrate path and at least one plenum air and/or air/combustible
gas mixture distributor is provided.
[0013] Irradiation elements are positioned at a minimal distance
from the substrate path in order to obtain a maximum of heat
transfer efficiency and avoid unnecessary substrate distortions,
e.g., cause wet bands in the substrate due to the temperature
differences of the housings in relation to the irradiation
elements.
[0014] Most of equipment known in the art has such minimal distance
limited by the housings. If they are closely positioned, "heat
shadows" are created and it causes wet bands in the substrate. A
good housing positioning is necessary for avoid such shadows. By
other hand, the necessary positioning reduces the equipment
radiation ability and creates an air/combustion gas stream which
makes the substrate drying difficult. Thus for avoid this problem,
additional heat equipment is provided in order to keep a good
global efficiency.
[0015] Other problems related to combustion gas mixture quality may
occur. The systems of the art generally employ a not standard
combustible gas mixture composition. Such differences can alter the
burning stoichiometry at the irradiation elements. So, the flame
can return to the inner part of the equipment at the plenum zone or
at the gas injection tips and cause explosions and the process is
to be interrupted for repairs for long term.
[0016] Another problem of the art is the employment of several
feeding heat recovery ducts. Ducts occupy a considerable space in
the production plant and it reduces a best employment of the plant
space and makes a new equipment installation dificult.
[0017] Some recent techniques employ irradiation elements made of
continous refractory ceramic plates as a radiation emitter. Such
plates are designed for cover all width of the process and are
longitudinally positioned at one or more sections. Such arrangement
comprises a limitation when the process is to be fitted for other
ends.
[0018] Such models presently satisfy IR irradiation quality and
operation maintenace necessities, but some problems are still
found: [0019] Framed housings provide cold zones (shadows) and a
bad heat distribution, thus the irradiation element is to be
positioned farer and the global efficiency is reduced; [0020] The
power modulation is necessary in some cases; therefore IR emission
bands are moved to large waves region (Planck Law for Black
Bodies). This changes reduces the penetration feature of IR rays,
because the way of energy is absorbed depends on the length of the
wave emitted from the emission element and it causes temperature
gradient differences in the substrate, the evaporation is not
effected and the substrate surface is burned. Depending on the
technique an wave modulation is not possible; [0021] Equipments
found in the art are not suited for permit sample collection from
an open chamber and the residual oxygen content after the
combustion is not detected. [0022] Even all safety steps have been
taken, all equipment of the art are potentially dangerous and an
explosion hazard is possible. Irradiation elements manufacturers of
the art consider this possibility hard to occur, thus the design of
such irradiation elements did not involve safety care.
[0023] Industries of the art need safe and low maintenance
equipment for reduce the interruption time for repairs.
SUMMARY OF THE INVENTION
[0024] According to the above discussed and in view of the above
mentioned problems, the present invention provides a modular IR
irradiation apparatus which employs combustion gas and its
respective integrating devices for automatically control the
air/gas mixture, for sequencing the process starting, for
interlocking the equipment and the corresponding process. Some
modifications in the irradiation modules have been done in order to
eliminate shadow zones and to enhance gas flowability; such
improvements are achieved by means of a fibrous ceramic. The fibrou
ceramic have flexible pores through which the air/gas mixture flows
and after the air/gas mixture emerges from an escape surface an
ignition means is driven and a fire line provided and kept stable
over the ceramic escape surface which acts as IR irradiation
element at high frequency bands.
[0025] This preferred embodiment permits a safe operation, because
the flexible fibrous ceramic does not resist to pressure, causing
minimal intensity explosions and provides soft fragments when
exploded. The modular design permits multiple arrangements being
fitted to any drying processes, enhances the continous irradiation
element operation.
[0026] All the above objectives are achieved acorrding to the
following steps: [0027] Refractory flexible irradiation module
comprising stopping means which are high temperature resistant and
avoid shadow zones and side losses of heat at the burning zone in
the ceramic surface; [0028] Employment of refractory flexible
ceramic plates having flexible pores which permit air/gas
modulation, the flexible pores permit define the path of the
air/gas mixture through the ceramic plate. When the flow pressure
of mixture is reduced, part of the pore automatically close and the
combustible mixture is coducted to the surface where the hot fibers
are placed. The fibres keep the combustion active at the surface,
multplying IR heating effects. Ceramic plates of the art tend to
"swallow" the flame causing an inner burning and reducing the
efficiency of the process and/or loss of the control of the flame
and equipment explosion. [0029] Sensors and measuring means are
provided for monitoring all steps: Thermal sensor--safety device
applied in the lower face of each flexible fibrous ceramic module,
more particularly fixed in the support screen of the ceramic plate
and extending to median line of such plate, for monitoring a
possible heat flow inversion due to external factors which cause
the "flame swallowing". For example, a heat reflection means
positioned in front of the irradiation element in order to return
IR energy back to the irradiation element and creating an
ressonance effect for store heat in the irradiation element and
make the flow inversion. This device avoid misemployment problems
by blocking the irradiation element. This provides an extended work
life of the ceramic plate. Oxygen measuring means--Continous
measuring based on Zirconinum oxide. This device collects
combustion gases over the burning surface in at least one module of
refractory ceramic, for continous analysis ends, permitting a flame
optimization e an after buring residual oxygen controlling. Such
sensor is connected to a LPC (Logical Program Controller) of the
monitoring, interlocking and alarming system which is driven when
the level of oxygen does not match with the standard value.
Ultraviolet (UV) Flame detector--It is applied in the external face
of the metallic frame, more particularly, near to the combustible
gas inlet, for flame detection, i.e., for combustion detection in
the ceramic modules. The flexible ceramic concentrates the burning
in its surface, the IR generation occurs basically in the short
waves range, including some residue at the begining of the UV
spectrum which is identified by the UV detector. The UV detector is
assembled as an cathode anode discharge vessel, known in the art,
inserted in a housing or specially designed device for support
severe operation conditions. The housing have a cylindrical shape
made of metallic material provided with a lower hole and channels
for better air circulation. Refrigeration air flows from
refrigeration ribs and also from the ceramic discharging tube of
the receptacle body of the sensor, keeping the inner pressure
positive and external particulate material entrance is avoided (the
equipment can use two UV flame detector); Bed--all flexible
refractory ceramic modules and the first and the second plenum
distribution means are positioned in the bed which is made of
metallic plates having two handles and two mirrors and botton caps
and couterventing strips. Between the handles and the bottom caps a
safety system is provided for permit an easy opening of the caps
for maintenance or for avoid bed expanding in case of explosion.
The locking system permits determine the effects of an
explosion.
APPLICATIONS AND ADVANTAGES
[0030] Several advantages are achieved by means the present
invention. The novel modular IR irradiation means and its eletronic
devices permit a better control during the operation and an
enhanced global efficiency for thermal energy.
[0031] Other advantages are as follows: [0032] Flexible ceramic
modules of the present invention permit uniform IR emission in all
burning zone, avoiding shadow zones without irradiation; [0033] The
absence of shadow zones permits that the irradiation surface be
placed near to the substrate avoiding losses caused by air/gas
streams and providing a collimation cavity for IR emission for
avoid radiation scattering. [0034] Ceramic plates stopping in the
irradiation modules comprise other feature of this invention, since
it meets thermal-phisical requirements and avoid energy dispersion
over the limits of burning zone edges. [0035] LPC can be programmed
for logoff some modules when other are still active and meet
substrate width variations requirements. [0036] The fiber web has
some anisotropic free grade related to a particular moviment. When
the gas passage is forced through the flexible ceramic, other pores
are forced to open avoiding pore saturation, making the pores
equivalent in relation to the conduction ability of the mixture.
The average pore diameter is automatically adjusted for keep
balance between the pores. This permits a gas volume and the power
level modulation and keep the discharge rate controlled and fitted
to the minimum limit. [0037] The oxygen measuring means application
makes possible the residual smoke collection after the burning for
continous monitoring of the residual oxygen and this system can
detect failure in the combustible gas feeding. Other feature of
such means is that it is able to keep a high burning efficiency and
keep the previous defined stoichiometry for obtain the desired
temperature and IR band results. [0038] Two retangular plenum
employment as mechanical support of the modules permits the gas
mixture feeding in the modules by means modular valves or blocking
valves, when modifications and/or improvements are necessary.
[0039] The metallic frame building having inner pressure rate and
overpressure alleviating means, meets the safety requirements as
the explosionproof equipment, providing a safe operation for
workers and equipment.
DESCRIPTION OF THE DRAWINGS
[0040] The present inventio is best defined, but not limited to,
according to the drawings as follows:
[0041] FIG. 1 is a perspective view of the modular heat irradiation
element provided with some irradiation modules in ready to use
position and one module in exploded view;
[0042] FIG. 2 is cross sectional view of the IR irradiation element
of the present invention;
[0043] FIG. 3 is exploded perspective view of a irradiation module,
illustrating all its components;
[0044] FIG. 4 is a sectional view of an oversized detail of the
stopping means in the ceramic plate;
[0045] FIGS. 5 and 6, illustrate, respectively, side and sectional
views of the irradiation module;
[0046] FIG. 7 is a perspective view of part the bed and primary and
secondary plenum distribution ducts;
[0047] FIG. 8 illustrates the entire bed with more details, in
exploded perspective, showing the positioning of the oxygen
measuring means and flame UV detectors;
[0048] FIG. 9 is a cross sectional view of the bed, showing the
mounting system with safety device for alleviating the
explosion;
[0049] FIG. 10, is an oxygen measuring means, in a more detailed
perspective view;
[0050] FIG. 11 illustrates the oxygen measuring means mounted on
the IR modular irradiation element;
[0051] FIG. 12 is an exploded perspective view of the UV sensor
bulbs support housing; and
[0052] FIG. 13 is sectional view of the UV flame detector of the
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0053] Referring to the Figures, the present invention refers to a
MODULAR INFRARED IRRADIATION APPARATUS AND ITS CORRESPONDING
MONITORING DEVICES, the modular heat irradiation apparatus (1) is
directed to heat transfer operation involving elevated rates of
heat to be contoinously traferred to a receiving substrate, e.g.,
industrial drying process of fibrous products as paper or cellulose
(L) (FIG. 2).
[0054] According to the present invention and FIGS. 1 and 2, the
modular heat irradiation apparatus basically comprises a metallic
frame or bed (2) which is designed for receive a number of
irradiation modules (7), according to process width and in such
manner to receiver distribution and support ducts, priamary plenum
(3p), secondary plenum (3s) which possesses gas/ar (G) mixture
feeding outlets (3a) to the modules (7).
[0055] The employment of two plena having rectangular shape (3p and
3s) serve as mechanic support fo the modules (7) in order to
position them in such manner to permit the gas/air mixture (G)
feeding in the modules (7) by means a modulation/blocking valve
(VL) coupled to the primary plenum (3p) or blocking free directly
coupled to the secondary plenum (3s). The module presents an unique
mixture (G) inlet (4) whic can be positioned aligned to the primary
plenum (7v) or secondary plenum (7d), depending on the final
application which can be defined by turning the module 180.degree.
and by opening passageway (3a) of the primary plenum (3p).
[0056] Such procedure can be accomplished even after the original
assembling be concluded when a modification is necessary or when
powe control is to be installed.
[0057] Plena (3p, 3s) are fed, firstly by the primary (3p)
employing at least one side duct (G), which is further used by the
secondary (3s) by means of an inner joint (JR) which is optionally
and restricting means (FIG. 7).
[0058] The bed (2) is made of two mirror joining (LI/LC) having
lower laterals (LI) and axle type fixing supports (4) (FIG. 1)
which are fixed to the processes by means of locking bearings (M),
permitting adjsutment of the equipment angle at the moment of the
installation in relation to substrate flow direction (L).
[0059] Also, the bed has the upper side (LS) comprising lateral
channels for alleviating thermal dilatation (AD) and resist to
temperature variations between the upper edge and the lower edge
and receiving refractory material (MR) to the irradiated IR, in
order to define one irradiation cavity (CR), joined the frontal
face, which is provided with irradiation modules (7). Such modules
(7) are trasnversally positioned to the longitudinal axle of the
bed (2) and arranged side by side in order to define a regular
planar surface. The bed is further closed by metallic caps (6)
which description will be provided after.
[0060] The mirror (EI) of the bed (2) (FIG. 1) is provided with
sealing air inlet duct (AS) for keep the inner cavity of the
equipment pressurized and refrigerated; such air inlet has an
independent feeding and is directed to avoid entrance and storing
not desired materials and gases in the cavity, protecting the frame
against gas losses. The pressurized air is directed to UV system
refrigeration and venturi system, both detailed in the present
appliation.
[0061] Irradiating modules (7) can be made in variable dimensions
and width, and according to FIGS. 3,4,5 and 6 each one of the
irradiation modules(7) is made of metallic material base
receiver(8), containing a feeding hole (9), positioned and not
centrallized in relation to the surface of such base, for aligning
with other plenum support (3p/3s) at the moment of the mounting,
just inversing the module according to the plenum. The mounting at
the side of the plenum (3p or 3s) is achieved employing a stopping
ring (11) fitted to the feeding hole (9), which ring permits a good
positioning of the module when the fixation occurs over the
distribution plena (3p, 3s) and each module (7) is fixed in the
plena by screws restraining pins (P).
[0062] The base (8) receives at its free edge, a screen (12)
containing holes (12a) having suitable dimensions and shapes, in
the lower face of the screen (12) are fixed at least two sets of
sensors of thermal flow (14) interconnected by the electronic
circuit (13); such sensors extend over the screen to deep contact
the penetration layer of the ceramic (15) where the sensors are
fixed thereto. The sensors are interconnected to an electronic
device (14a), which is connected to the LPC central, not shown.
[0063] At the upper face of the screen (12) is positioned a porous
flexible refractory ceramic plate (15), in which median part, under
the central line (Y) (FIG. 6), the thermal flow sensors (14) are
kept positioned. The housing deep is determined at moment of the
mounting.
[0064] Each refractory flexible ceramic plate (15) (FIG. 4) is made
of sealing means (S) which are high temperature resistant and
arranged in thin ceramic housings (16) and placed at the side faces
of the ceramic plate by means of a high temperature resistant
elastomer (17) layer (FIG. 4) which is able to penetrate between
the parts (15, 16) in order to produce and anchoring phenomena,
adhering to said parts and avoiding lateral dispersions (D) of
combustible gas in the ceramic plate through the screen holes (12a)
by stopping them. This keeps the burning zone restricted to the
face (D1) in the surface of the ceramic plate (15).
[0065] The block comprising the flexible refractory ceramic plate
and the thin ceramic housings (16) are fixed to the screen (12) by
means of an elastomer layer (17) suited to high temperatures,
complementing the sealing means of the irradiation modules (7) and
producing a flexible joint which supports natural vibrations which
occur during the operation of the equipament and fit different
materials possessing very thermal dilatation coeficients, i.e., the
different ceramic materials and the metallic carcass.
[0066] One of this features of the refractory ceramic plate (15) is
the flexible pores (see detail A in FIG. 3), where the fiber
positioning (F) kept ready to move (V), due to forced passage of
gas (G); this free movement feature permits a dynamical
distribution of the gas flow through the pores (R) of the fibrous
structure, thus making the pores open and/or closed when necessary,
depending on the use condition and keeping the balance between
them. The gas volume flowing through the ceramic plate is able to
be modulated and the emission power of the irradiation element is
indirectly modulated by varying the combustible gas volume (G), but
keeping active the discharge rate of the pores compatible to the
combustion rate, therefore, the flame is stably positioned at the
first layers (D1) of the flexible ceramic.
[0067] Other feature of the flexible ceramic (15) is that even
under mechanical erosion the above mentioned properties are
maitained, because the above described phenomena, which keeps the
flame balance, occurs in the surroundings of the fire line, i.e.,
at the first 3 mm to 5 mm deep of the flexible refractory ceramic
plate. Erosion or removal of part of such surface material does not
modify the flame balance which always occurs at the surface (D1) of
the ceramic plate independently of the surface shape.
[0068] Another property of the ceramic plate associated to the
flexibility feature and not affected by erosion, as stated above,
is the ability of the irradiation element resist to dropping
contamination, e.g., ink dorps in a continous painting process of
paper. The drop material at the surface of the irradiation surface
can be easily removed by mechanic procedures of scratching or
abrasion avoiding other cleaning procedures and the system is
quickly restored.
[0069] The bed (2) (FIGS. 1,2 and 8) as previously stated, is made
of lower side metallic plates (LI) having angular flaps (18a),
closing mirrors, blind mirror (EC) and instrument mirrors (EI)
having holes suited to the devices to be fixed therein and botton
caps (6) having side flaps (6a) e closing flaps (22 and P1); such
side plates (LI) are alterned with counterventing channels (21)
while the botton caps (6) have one flap (22) at one side fixed by
engaging to one of the LI flaps (18), and at the other side, the
flap is fixed by means of screws (P1), therefore is provided one
safety devide between the lower side plates (LI) and the bottom cap
(6), the particular geometry feature of the caps permits that the
flaps (18, 22) be easily unlocked offering an escape area for
gases, in the case of internal explosion, the cap (6) is fixed to
the structure by means of the screws (P1) for permitting the
removal of the cap for maintenance ends.
[0070] Modular heat irradiation apparatus (1) is equiped with
automatic lighting devices and monitoring means, which are
interconnected to the LPC, not shown, such devices comprise the
trigger (CT) and sensors of thermal flow (14), oxygen measuring
means (23), and the UV sensor (FIG. 13), better detailed ahead.
[0071] Automatic lighting system comprises the assembling of some
trigger electrodes (CT). The lighting is produced by inonizing the
air by using a high tension source which discharges over the bed
(2). The triggers are mounted in a number which is enough for
permit the lighting of the irradiation element even part of such
triggers are disabled.
[0072] Thermal flow sensor (14), which position has been previously
detailed, is the responsible for monitoring de heat flow inversion,
since each sensor (14) monitores a maximum temperature differential
between the median line (Y) of each ceramic plate (15) and the
temperature of the feeding gas of the module, the verification
occurs at the LPC for turn the equipment off when the differential
is greater than maximum permitted limit, this would indicate
thermal flow inversion, i.e., the flow is returning to the gas
plenum and probably an explosio would occur. The thermal flow
sensor is also used to indicate an erosion process in the ceramic
plate and the replacement of such plate is necessary.
[0073] The Oxygen measuring means (23) (FIGS. 10 and 11) employ, a
sensor (26) based on Zirconium oxide, which is positioned in one
device containing a temperature controlled chamber (26)
(temperature control system not inidicated), and such device is
formed by five tubular bodies (27, 28, 30, 31 and 33) welded (29)
one to the other, the set (23) is fixed by a holder (34) positioned
in the inner flap of the upper side (LS). An extension is fixed to
the tubular body (28) forming a venturi type system (30), the tube
(30) having the greatest diameter conducts the sealing pressurized
air inside the bed to outside. When the sealing air passes between
the tube (30) and the broader section of the tube portion (31) it
is accelerated in order to effect vacuum inside the portion (31)
and in the body (28), providing a vacuum chamber, while the
collector tube (33) conducts the smokes collected in the inner part
of the chamber (28). The collection tip (35) is coupled to the
upper portion of the tube (33) and holes and the concetrating flaps
(37) are provided in the lower part (36) of such tip. The lighting
system also employs the the tip (35) as ground contact for
discharge the trigger.
[0074] The oxygen measuring means (23) is applied near to the
burning zone, (D1) in order to continuous analyze the combustion of
the irradiation element, optimizing the burning and controlling the
amount of residual oxygen after the combustible burning. Such
sensor is connected to the LPC of the monitoring system. Parameters
of operation are adjusted in view of the desired application and
the kind of combustible gas is used.
[0075] UV detector (24) (illustrated in FIG. 1 and more detailed in
FIGS. 12 and 13) can be double assembled, i.e., two flame detector
(24) can be for each irradiation element (FIG. 1), each detector
has an UV sensor bulb which is commecially available and its
respective encapsulating system (39) installed inside the cooling
system (40) extending to collimation cavity of IR emission (CR) by
a ceramic bulb (47) restricting and protecting the sight of the
bulb and the sight field against obstructing clouds of vapor from
the process or against UV emissions from other external sources. UV
sensors (24) are positioned at the external side of the the
instrument mirror (EI), more particularly fixed to the supports
(44) which are fixed by tubes which are employed to conduct the
pressurized sealing air inside the support tube from the
irradiation element (4) to the cooling body (40).
[0076] Each set of UV detector (24) additionally comprise a cooling
body (40) having ribs (41) at its external face in order to provide
cooling channels for keep the internal housing chamber (42) of the
sensors (38, 39) cool; such protection comprises a lower hole (43)
which is coupled to the metallic box type support (44) through
which cooling air and connection wires of the electronic excitation
and monitoring (called flame relay) are conducted.
[0077] The ceramic protector tube (47) is fixed to the cooling body
(40) by the flange (45) which possesses inner tips as restraining
means (46) of such tube (47).
[0078] A skilled person will see that the scope of the present
invention is novel: irradiation modules, the monitoring performed
by the sensors and measuring means via discrete electronic controls
or LPC, the modular heat irradiator and its improved shape, a high
efficiency of the heat transfer between the irradiating surface and
the receiving substrate, the equipment designed for being easily
adapted in any industrial process and all benefical effect achieved
by this means which permit remarked improvements in the volatile
removal from substrates, particularly wet removal from paper ou
cellulose drying processes and the invention concept which permits
a long term use of the equipment of the present invention and
reducing maintenance interruptions.
[0079] Even the above mentioned invention be detailed for offer a
better understanting, the same is not limited to the revealed
applications or particular details presently revealed.
[0080] Other embodiments and variations of the present scope is
intended as belonging to the present invention.
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