CA1176842A - Apparatus for hot air drying and simultaneously supporting continuous webs, particularly printed paper webs - Google Patents
Apparatus for hot air drying and simultaneously supporting continuous webs, particularly printed paper websInfo
- Publication number
- CA1176842A CA1176842A CA000388641A CA388641A CA1176842A CA 1176842 A CA1176842 A CA 1176842A CA 000388641 A CA000388641 A CA 000388641A CA 388641 A CA388641 A CA 388641A CA 1176842 A CA1176842 A CA 1176842A
- Authority
- CA
- Canada
- Prior art keywords
- web
- heat
- nozzles
- air
- casing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B13/00—Machines and apparatus for drying fabrics, fibres, yarns, or other materials in long lengths, with progressive movement
- F26B13/10—Arrangements for feeding, heating or supporting materials; Controlling movement, tension or position of materials
- F26B13/101—Supporting materials without tension, e.g. on or between foraminous belts
- F26B13/104—Supporting materials without tension, e.g. on or between foraminous belts supported by fluid jets only; Fluid blowing arrangements for flotation dryers, e.g. coanda nozzles
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B21/00—Arrangements or duct systems, e.g. in combination with pallet boxes, for supplying and controlling air or gases for drying solid materials or objects
- F26B21/02—Circulating air or gases in closed cycles, e.g. wholly within the drying enclosure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B23/00—Heating arrangements
- F26B23/001—Heating arrangements using waste heat
- F26B23/002—Heating arrangements using waste heat recovered from dryer exhaust gases
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/10—Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working
Abstract
ABSTRACT OF THE DISCLOSURE
The invention relates to the field of hot air drying apparatus, with simultaneous support, for continuous webs of flexible material, especially paper webs coming from offset printing groups. The problem set is to ensure uniform drying while maintaining adequate rigidity of the apparatus. According to the invention, such an apparatus is characterised in that the housing (2) comprises at least two separate sections (5a, 5b) fixed together, each of these sections including a blower set (23a-9c-9d, 23b-9c-9d) comprising two rows of nozzles (9c, 9d) and a recycling fan (23a, 23b) whose input communicates with the inside volume of the housing (2) and whose output is con-nected with said rows of nozzles (9c, 9d) through ducts (12c, 12d) provided with heat addition means (27) connected to the source of heat (24). The invention is mainly used for drying paper webs coming from printing machines.
The invention relates to the field of hot air drying apparatus, with simultaneous support, for continuous webs of flexible material, especially paper webs coming from offset printing groups. The problem set is to ensure uniform drying while maintaining adequate rigidity of the apparatus. According to the invention, such an apparatus is characterised in that the housing (2) comprises at least two separate sections (5a, 5b) fixed together, each of these sections including a blower set (23a-9c-9d, 23b-9c-9d) comprising two rows of nozzles (9c, 9d) and a recycling fan (23a, 23b) whose input communicates with the inside volume of the housing (2) and whose output is con-nected with said rows of nozzles (9c, 9d) through ducts (12c, 12d) provided with heat addition means (27) connected to the source of heat (24). The invention is mainly used for drying paper webs coming from printing machines.
Description
~L~6~39~
The present invention relates to hot air dryin~ apparatus, with simultaneous support, for continous webs of flewible material coming from a prev;ous treatment requiring evaporation and removal of liquid substances which can be vaporised, especially drying webs of printed paper coming from an offset press line and from which the solvents of the deposited ink are to be eliminated (only solvents consisting of light oils when greasy inks are used, fixed by the application of heat).
The invention relates more particularly to apparatus of the kind comprising a housing within which are disposed, between two web inlet and outlet openings, two rows of nozzles disposed one above and one below the plane of movements of the web, these nozzles presenting air ejection slits extending transversing relative to the direction of movement of the web, the slits opening towards the web to de dried, said nozzles being connected to at least one recycling fan and a source of heat, the housing connecting also with an extractor fan.
Due to this arrangement, the substances to be evaporated, for example, the solvents of the printing inks, are removed in a short lapse of time, due to the intensive thermal exchange, while the jets of hot air emitted by the slits of the nozzles ensure continous support of the web between the nlet and outl~t o~enings, av iding any cont3rt of the weh w~th the components of the apparatus, which might prejudice conservation of the result obtained on the web by the preceding treatment in question, producing, for example, swearing of the still wet i-nk in the case of printed paper. In the same particular case, the webs coming from the offset rotors run at speeds which are frequently 5 to 10 m/s and the hot air is blown at a tempe-rature of 150C to 300C, consequently the web of paper is heated to 120C
to 160C and it is desirable to cool it before cutting and folding it. The nozzles of the upper set are offset relative to those of the lower set, which creates undulations in the longitudinal direction which cancel out the transverse undulations which tend to be produced under the effect of the web tension.
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The present invention relates to hot air dryin~ apparatus, with simultaneous support, for continous webs of flewible material coming from a prev;ous treatment requiring evaporation and removal of liquid substances which can be vaporised, especially drying webs of printed paper coming from an offset press line and from which the solvents of the deposited ink are to be eliminated (only solvents consisting of light oils when greasy inks are used, fixed by the application of heat).
The invention relates more particularly to apparatus of the kind comprising a housing within which are disposed, between two web inlet and outlet openings, two rows of nozzles disposed one above and one below the plane of movements of the web, these nozzles presenting air ejection slits extending transversing relative to the direction of movement of the web, the slits opening towards the web to de dried, said nozzles being connected to at least one recycling fan and a source of heat, the housing connecting also with an extractor fan.
Due to this arrangement, the substances to be evaporated, for example, the solvents of the printing inks, are removed in a short lapse of time, due to the intensive thermal exchange, while the jets of hot air emitted by the slits of the nozzles ensure continous support of the web between the nlet and outl~t o~enings, av iding any cont3rt of the weh w~th the components of the apparatus, which might prejudice conservation of the result obtained on the web by the preceding treatment in question, producing, for example, swearing of the still wet i-nk in the case of printed paper. In the same particular case, the webs coming from the offset rotors run at speeds which are frequently 5 to 10 m/s and the hot air is blown at a tempe-rature of 150C to 300C, consequently the web of paper is heated to 120C
to 160C and it is desirable to cool it before cutting and folding it. The nozzles of the upper set are offset relative to those of the lower set, which creates undulations in the longitudinal direction which cancel out the transverse undulations which tend to be produced under the effect of the web tension.
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2.
Apparatus of this kind is already known~ for example from U.S.A.
Patent n 3 739 491, in which the housing is in a single piece over the whole length of the apparatus and incorporates the source of hot air, which is a single source for the whole apparatus and is disposed asymmetrically.
However, certain disadvantages appear when drying apparatus of this kind is to be adapted to treatment lines operating at high speeds, such as high speed printing rotors (speed reaching 10 m/s).
Thus, for example, the input of substances (for example so1vents bearing other components of the ink? becomes high and their dew point rises (40C, up to 70C) so that condensation occurs at the drying air inlets, which can produce spotting of the web, or even blocking of certain openings, producing a loss of support which can require stoppage of the apparatus and of the whole line. Essentially, it is the cold air from outside entering through the web inlet and outlet openings which forms a source of condensa-lS tion like a mist as it needs the hot air loaded with solvent rising fromthe web.
It should also be noted that, in the case of printing, on a given apparatus, the quantity of solvent varies to a very considerable extent, and can reach over a ratio of 1 to 100, depending on the substance, so that in some cases the concentration of solvent is too high and produces an undesirable condensation, even if on certain apparatus one tries to maintain a constant pressure drop by controlling the flow rate of extraction of used air as a function of this pressure drop, this regulation of the pressure drop being quite insufficient in the case of maximum concentrations of solYent.
Moreover, in certain applications to treatment lines, the increase of runningspeeds of the webs requires the des;gn of drying apparatus of greater and greater length, because then they are more economical, and consume less energy than short drying tunnels, but then there is a limit because the structure of the support for the nozzles at the operatins temperatures used, which can reach 300C, then has mechanical strength defects, twisting and curving under the effect of the thermal stresses.
In certain other apparatus, the fan and burner are disposed beneath and above the drying zone itself (which comprises the nozzles), with the ran downstream of the burner, and connected to the nozzles by a wedge-shaped chamber, which has the disadvantage that, if the flame blows through (because of a drop in air pressure or an ;ncrease in gaz pressure), i~ reaches the fan, which damages the fan and can even destroy it, besides which with such an arrangement, the fan pressure being related to air density, thus to its temperature which can vary from 120C to 33~C,sign;-ficant pressure variations can occur which are also unfavourable to the required uniformity of blowing and adequate support of the web. -Finally, the thermal energy consumption of these known appara-tus is very high, because of the high flow rates of used air (extracted), which moreover also requires the use of large upstream cleaners which also consume a lot of energy. This flow rate is due particularly to the entry of quantities of cold air through the inlet and outlet openings in the housing which cannot be reduced without risk of blocking the recycled air, loaded with solvents.
As for the side structure of the system, some known apparatus have a main hou6ing which only contains the nozzles and the means extrac-t,ng used air, whereas the .an and burr,er, wnich constitute the means for - reheating the air supply, are placed in a separate housing disposed on the side of the first ho~sing and connected to it by sleeves. It follows that this arrangement is difficult to adapt to the available space offered for the installation of the apparatus, and moreover prevents any extension of the apparatus required by an increase of speed.
In general, the installation of two drying tunnels "in lin ", even touching, has the disadvantage of not ensuring equal spacing of the nozzles at the interface zone, and consequent reliable web support.
Accordingly, the present invention has as object to avoid the various disadvantages of the known drying apparatus.
3L~ 7t;~3~ 4.
Thus, the invention provides an apparatus of the kind referred to, characterised in that, in the direction of movement of the web, the housing comprises at least two separate sections which are fixed together each section comprising a set of nozzles which comprises two rows of nozzles and a recycling fan whose input communicates with the inside volume of the housing and whose output is connected to said rows of nozzles through ducts provided with heat addition means connected to the source of heat.
Due to this arrangement, the complete housing of the apparatus which, for the high running speeds now required, especially on offset prin-ting rotors, has to have a considerable length, for example 7 m approxima-tely, is subdivided into a plurality of sections,for example two or three, or more if required, and they can even be juxtaposed indefinitely, since these sections are practically identical, except for those which also bear the common source of heat or the common extractor fan, thus making the structure perfectly modular and adaptable. If follow that the length of each section can be limited to a suitable value, for example of the order of 2,5 m for normal web sizes, or 3 m for small web widths (given that the wider the apparatus has to be because of the web widths to be treated, the more the number of sections in line can be increased, so as to reduce the flow rite to be produced on each recycling fan). Th;s subdivis;on of the housi~g thus enables each of its sect;ons to be guaranteed a su;table mechanical strength at the nozzles. The subdivision also, by enabling a regular spacing of the nozzles connected to the recycling fan of each section, improves the uniformity of blowing and the temperature distribution.
In particularly advantageous fashion, the distance between the last nozzle of one sect;on and the f;rst one of the next can be equal to the d;stance between the nozzles of a given section, which thus ensures a constant spacing of the nozzles from one end to the other of the hous-ing and avoids any interruption in the support of the web, so that no flapping of the web will appear on passing from one section to the next.
~ qore particularly, the present invention relates to an apparatus for simultaneously drying in hot air and supporting a continuous web of flexible material. The apparatus comprises a casing defining a web inlet opening and a web outlet opening for the web which travels through the inlet opening and the outlet opening in a general path longitudinally through the casing. Each supply means and exhausting means for exhausting used air from inside the casing are provided. The casing comprises at least two sections defining chambers in adjacent relation longitudinally of the casing, each section having an upper set of nozzles and a lower set of nozzles disposed respectively above and below the general path. Each section includes air recycling means having input means communicating with the inside of the casing and output means, duct means putting the output means in communication with the upper set of nozzles and the lower set of nozzles of the respective section and heat adding means for putting the heat supply means in communication with the duct means for adding heat from the heat supply means to the air recycled to the sets of nozzles by the output means of the recycling means.
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3L~'~t~ 5.
In a preferred embodiment of the invention,at least one end section of the housing can contain a burner which is associated with a combustion chamber.
In a particularly preferred embodiment of the invention, the source of heat can be provided by at least one burner disposed at the end of a combustion chamber presenting an inlet for recycled air connected to the output of a recycling fan, the inlet being situated upstream of the heat addition means for said ducts. This arrangement enables a mixture to be obtained in two stages, firstly dilution of the burner gas with air coming directly from the recycling fan associated with this burner, and secondly dilution with air sent by the same fan directly to the blower ducts, which gives greater flexibility in regulating the temperature and the pressure, and a more uniform temperature. Moreover, the positioning of the passages inputting heat to the blower ducts downstream of the recycling fan avoids any damage to or destruction of the fan.
Preferably the heat source can be common to at least two sections, the temperature of the air arriving at the nozzles of each sec-tion being regulable independently by dosing the heat input to each of the sections; in this way, for example, variable angle flaps can be disposed in the passages inputting heat to the blower ducts of at least one of the sections of the housing which enables the flow of burnt gas from the combustion chamber going to the different sections to be regulated, so as to obtain different temperatures in the sections and thus provide pro-gressive evolution of the heating of the moving web. These flaps can be controlled normally or automatically and, in the latter case, the flaps of one section can be connected to an automatic regulator device, itself connected to temperature pick-ups disposed in that section and in a juxtaposed section.
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6.
In an embodiment, it can be arranged that the nozzles of a given sect;on of the housing are split into at least two groups which are connected to the supply means of combustion gas recycled air mixture by two temperature regulating means, which are separately controllable.
The section can be separated, by means of partitions, into at least two parts, a control flap being formed by the same number of separately con-trollable members, which enables blower temperatures which are different and controllable to be obtained in the same section.
Preferably the extractor fan can be situated inside the hous-10 ing of the apparatus, in which case only its drive motor is disposedoutside, which avoids having to provide a special frame disposed on the envelope, eliminates the connecting ducts which would be heat insulated, and above all deadens the noise of the fan.
In particularly advantageous fashion, each of the web inlet and outlet openings in the envelope is provided with two nozzles placed one above and one below, and which each present at least one air ejec-tion slit extending transversely relative to the direction of web move-ment and across the whole width of the web, these nozzles being connected to a source of a;r external to the envelope Gf the appara~us and which is associated with pre-heating means. In this way, these nozzles form curtains of air which obstruct the entry of outside air through the inlet and outlet openings, the air blown in the form of a curtain being taken from outside the housing and pre-heated, which eliminates the risk of condensation within the housing and also reduces the required extraction flQw. Preferably, the upper and lower nozzles of each of the inlet and outlet openings can each present two slits spaced apart in the direction of web movement, the space between the upper slits being offset and par-tially overlapping relative to the space between the lower slits.
This arrangement creates an additional node on the path of the web, at the inlet or outlet of the housing thus stabilising further 3l1'7~j~3~2 the web movement, particularly at its entry into the housing where it elilninates flapping which would lead to harmful contacts. Moreover, the creation of this additional node, adjacent the inlet or outlet opening, reduces practically to zero the play of the web in the opening, such that the height of the opening can be made minimal and reduce practically to zero the inflow of external air which might enter the housing through this opening (the flow being a function of the cross-sectional area of the passage presented and of the speed of flow, therefore of the diffe-rence in air pressure between the inside and the outside).
Conveniently, the external air source can comprise a fan for combustion air associated, as well, with the heat source, which avoids having to instal an additional air source and enables a reduction in energy consumption since, in normal operation, the burner only works at approximately one third of its power, the maximum power only being used during warm-up of the apparatus, while moreover there is no disadvantage in having a lower air pressure in the inlet and outlet nozzles during warm-up since there is not yet, in this phase any solvent passing through the apparatus which might produce condensation.
; Preferablyj again, the pre-heat.ng means can cnmprise a he~t exchanger situated in the combustion chamber of the burner of the appa-ratus which avoids using any additional source of pre-heat.
Thus the pre-heating means can be arra-nged to comprise a system for recovering heat from one of the two heat bearing elements consisting of the dried web and the air coming out of the extractor fan (with or without filtering of this air).
In a particular embodiment the external air source and the heat recovery system can be associated with a web cooler disposed at the output of the drying apparatus (the fan for burner combustion air can, for example, take air in from the hood of the web cooler).
3Ll'~t~ Z 8.
Preferably the control of the extractor fan flow can be connec-ted to an automatic regulat;on device, itself servo-ed both to an element measuring the pressure difference between the inside and the outside of the housing and an element for measuring a second parameter relating to the concentration of solvent occurring in the apparatus. This enables extraction to be reduced when the solvent concentration is low and to in-crease it when the concentration is high, this regulat;on being essential to avoid the undesirable condensation referred to above. The second para-meter used can comprise, for example, the rotor speed in the case of a press line, the power of the burner or again the concentration of oxygen in the housing or the solvent concentration itself in the extracted air.
Preferably, the longitudinal members bearing the nozzles com-prise tubes presenting air flow orifices which communicate with said nozzles and are open at their ends, so that a small part of the blown air penetrates these longitudinal members and ensures a uniform temperature.
Other features and advantages of the invention will appear from the following description, by way of non-limiting example, with reference to the acoompa~ying drawings in which :
: Fig. 1 represents an external perspective veiw of an apparatus according to a particular embodiment, in accordance with the invention, and comprising two sections;
Fig. 2 represents a diagrammatic view of this apparatus in vertical section in a vertical longitudinal plane of the apparatus;
Fig. 3 represents a perspective view of a blower according to a particular embodiment of the invention and including a saparation wall, Fig. 4 represents a.transverse section of the part of the apparatus through which passes the web;
Fig. 5 represents a detail from Fig. 4 according to a parti-cular embodiment of the invention.
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~L1'~tj~4 ~ 9 The apparatus represented in the drawings is an apparatus for drying webs of printed paper coming from an offset printing line.
The apparatus comprises, mounted on a support consisting of feet 1, a closed envelope 2 which has a generally parallelopiped shape, comprising two vertical end faces 2a and 2b in each of which is formed an inlet ~3a) or outlet (3b) opening, in front of which is disposed a pair of nozzles 4a or 4b fixed outs;de on the end faces 2a and 2b, the two openings 3a and 3b defining a horizontal plane for movement of the web to be dried, the movement following a direction D extending horizon-tally from the inlet opening 3a towards the outlet opening 3b.
In succession in the longitudinal direction of the apparatus which forms the direction of movement D, thehousing comprises two separate sections comprising parallelopiped chambers 5a and 5b which are joined in a vertical plane 6 and are fixed together in this plane.
In the vertical direction, each of these sections 5a and 5b comprises two superposed chamber elements 7a and 7b, the lower chamber 7a forming the blower chamber, while the upper chamber 7b forms a reheating chamber, the elements being joined in a horizontal plane 8.
In each of the blower chambers 7a and 7b of the two sections 5a and 5b, are disposed two sets of nozzles 9c and 9d, disposed in two horizontal planes parallel to the average plane of the web B and placed at a small distance from this plane, for example 3 to 4 mm away. Each of the nozzles 9c or 9d comprises an elonsate bar extending transversely relative to the direction D, this bar being hollow and comprising, on its face towards the web B two parallel slits, transverse relative to the direction D and extending right across the width of the web B, these slits 10 being separated by a solid part which enables an air cushion to be created ensuring the support of the web B upwards or downwards.
The air bars 9c above the band B are disposed in alternation in the iongitudinal direction D with the lower bars 9d, of equal number, 6~2 lo.
so as to ensure equal spacing between the alternate bars with a pitch p.
The different nozzles 9c or 9d, disposed above or below the web are fixed to a collector or plenum llc or 11d which extends horizon-tally in the direction D along the whole set of associated elements, each collector communicating both with the air bars 9c and 9d and with a communication duct 12c or 12d, these ducts outputting into the collec-tors llc and 11d in the middle of the collectors lengthwise (although for clarity, the junction of the lower duct 12d has been displaced in the diagram to one end of the collector).
The same arrangement exactly is provided in the second section 5b of the envelope. The two upper collectors llc and the two lower col-lectors lld are positioned lengthwise, moreover, so that the same pitch p which separates the different nozzles of a given collector also separates the last nozzle 9d of the lower collector of the first section from the first nozzle of the upper collector of the second section thus ensuring perfect alternation of the air cushions fr~m one end of the housing to the other.
The lower collectors 11d are mounted in two parts telescopically sliding relative tQ each other in the vertical direction, with elastic seals 13 interposed between the shaped facing edges of the two component parts. The lower part of the lower collectors being fixed, their upper part which carries the air bars 9d can therefore be displaced vertically by a push rodard linka~e shown schematically at 14 and reacting against the housin~ itself. The mechanism 14 is controlled by a jack 15 which itself is supplied with compressed air 16 though a distributor 17. This enables the lower set of nozzles to be lowered either when the apparatus is shut down, for example for washing the plates, or during operation to avoid damage to the paper which, over-heated, would break and require the apparatus to be re-started, with a consequent considerable waste of time. The mechanism 14 supports the two longitudinal hollow tubular ~7~
members 18 which are disposed laterally, on opposite sides of the collectors 11d, and on which the nozzles 9d are fixed.
As shown more precisely in Fig. 4 and 5, each of the air bars 9c which communicates in its central part and by its its upper face with the upper collector or plenum llc, is also fixed and suspended at each of its two ends beneath one of the two hollow tubular members 18, which itself is suspended permanently from the envelope 2. Holes 19 are formed between these members 18 and the air bars 9c, so as to ensure that hot air penetrates inside the members 18 which are also open at their ends, this circulation of air ensuring, in this way, a uniform temperature. The same applies to the lower air bars 9d, which are fixed and carried in an exactly symmetrical fashion above other hollow tubu-lar members 18, fixed to a part 18a which can be displaced vertically using the mechanism 14. Holes 19 are also provided between the bars 9d and these members 18 to ensure a similar circulation.
Each pair of nozzles at the inlet 4a and outlet 4b presents a horizontal passage for the web B at the height of the inlet (3a) and outlet (3b) openings these horizontal passages 20 comprising nozzles consisting of slits transverse to the direction D, of which two are provided on each of the upper and lower faces of this passage, the two upper slits 21c being disposed alternately with the two lower slits along the hor;zontal direction D. These slits 21c and 21d are disposed at practically the same distance from the web B as the slits of the air bars 9c and 9d, and the slit 21d or 21c of each nozzle closest to the end wall 2a or 2b of the envelope is positioned as close as possible to the inlet opening 3a or to the opening 3a or 3b, this same slit 21c or 21d being also disposed at the same distance p from the closest air bar 9c or 9d inside. The air coming out of each of the slits 21c, 21d forms à curtain of air which separates the gases within the housing 2 from the external air. Moreover, the slits being disposed in pairs on opposite . ~
ti~4 ~
12.
sides of the hand, air cushions are formed which also maintain rodes of undulations in the path of the web B.
In each of the upper elements 7b of the two sections 5a and 5b, is a recycling chamber 22a or 22b, each of these chamberscommunica-ting with the outlet of a blower or recycling fan 23a or 23b which isfixed under the upper surface of the housing 2, so that only the drive motor 24 of each fan is disposed above the hous}~g. The two side ends of each of the chambers 22a or 22b are connected to vertical ducts 12c and 12b which output into the collectors llc and 11d.
In the outlet wall 2b of the hou~ing and at the level of the upper element 7b, a burner 24 is fixed which can be a mixed burner operating either on gaz or on fuel oil. Within the housing the torch of the burner which emits the flame 24a is surrounded with a certain gap 25, by a cylindrical combustion chamber, which extends from this burner as far as the front end of the blower chamber 22a. This combus-tion chamber 26 presents enlargedparts, at the level of the two blower chambers 22a and 22b, in the shape of hoods directed downwards and ; communicating through passages 27 with the vertical ducts 12c and 12d.
At the edges cf these pass~ges ?' are piv~cd control fa'ps 28 which enable the proportion between the recycled air coming from the fan 23a or 23b and the burnt gas coming from the combustion chamber to be varied.
In a particular embodiment, the control flaps 28 of the first section 5a are connected mechanically to a servo motor 29 which itself is connected electrically to a control device 30 receiving values given by two temperature pick-ups 31a and 31b disposed respectively in the two upper collectors llc. The control of the burner 24 is connected on one hand to a second temperature pick-up 32 disposed in the second section 5b or else to an infrared temperature detector 33 disposed downstream of the outlet block 4b. The input of combustionair for the burner 24 3L~ 7 6 ~3~2 13.
is connected to the output of a fan 34 which itself is fed from the hood of a cooler 44, disposed downstream ofthe drying apparatus, and through which the web B passes subse~uently.
On the p;p;ng supply;ng combust;on a;r to th;s burner, a second pipe 36 is connected which enters the combustion chamber 26, at the le~el of the chamber 22b and passes through this chamber to the other side so as to form a heat exchanger with this chamber, the pipe then subdividing to join the two inlet (4a) and outlet (4b) blocks in both their upper and lower parts.
The blower chamber 22b of the second section also communicates w;th a th;rd duct 37 wh;ch is bent round so as to house the combus-tion chamber in the vicinity of the burner and to communicate with the gap 25 left free round the burner so as to bring in recycled air at this po;nt.
Finally, between the two blower chambers 22a and 22b, there is provided an extractor fan 38 which ;s fixed under the upper wall of the housing 2 ;n similar fash;on to the fans 23a and 23b and which communicates w;th a chimney 39 venting to air. In the chimney ;s ;nter-posed a flap 40 for controlling the flow of air extracted which is con-trolled by a jack 41 receiving on one hand a signal com;ng from a regu-lation device 42 fed with air sensitive to the pressure drop within the housing and on the other hand a transm;tter 43 sensitive to the solvent concentration within the housing.
As shown m~re precisely ;n Fig. 3, the upper collector or plenum llc has the shape of an elongate parallelopiped chamber w;th a wedge-shaped end, that is to say a chamber whose cross-section ;n a vertical plane parallel to the direction of web movement D is a trapeze.
The alr bars 9c are fixed underneath and across the whole width of this chamber. Above this chamber, and across a part only of ;ts width, is disposed the duct 12c which, conversely, extends along the whole lensth ~ 4 ~ 14.
of the upper face of the plenum llc. At its upper end, this duct 12c com-municates with another feed chamber 22a, which extends over the same length as the duct in the direction D, which projects from it transver-sely (in the direction of the air bars 9c) and within which is disposed the recycling fan 23a. Within the blower duct 12c, is disposed a vertical partition 44 extending transversely, this partition being extended by a further partition 44a which also extends transversely over the whole w;dth of the collector 11_~ but is inclined generally parallel to one of the duct 12c are mounted, pivoting about a horizontal axis X-X, parallel to the direction of web movement D, two control flaps 28, 28' disposed on opposite sides of the partition 44 in this section of this duct 12c.
There are thus two air currents which pass on opposite sides of the partitions 44 and 44a to reach the group of air bars 9c positioned in front of the partition 44a and to reach the group behind it.
It should be noted lastly that it can be arranged for each section of the housing to contain two housing elements disposed in relation to each other above, below or beside, in any case transversely rel~tive to the direction of web movement, these elements comprising one the blower zone and the other the reheating zone, which presents a great flexibility of adaptation as a function of the space available or of any desired lateral extension of the apparatus. The reheating element of each section can be positioned remote from the blower element, in which case a third element establishes the connection between these two.
Apparatus of this kind is already known~ for example from U.S.A.
Patent n 3 739 491, in which the housing is in a single piece over the whole length of the apparatus and incorporates the source of hot air, which is a single source for the whole apparatus and is disposed asymmetrically.
However, certain disadvantages appear when drying apparatus of this kind is to be adapted to treatment lines operating at high speeds, such as high speed printing rotors (speed reaching 10 m/s).
Thus, for example, the input of substances (for example so1vents bearing other components of the ink? becomes high and their dew point rises (40C, up to 70C) so that condensation occurs at the drying air inlets, which can produce spotting of the web, or even blocking of certain openings, producing a loss of support which can require stoppage of the apparatus and of the whole line. Essentially, it is the cold air from outside entering through the web inlet and outlet openings which forms a source of condensa-lS tion like a mist as it needs the hot air loaded with solvent rising fromthe web.
It should also be noted that, in the case of printing, on a given apparatus, the quantity of solvent varies to a very considerable extent, and can reach over a ratio of 1 to 100, depending on the substance, so that in some cases the concentration of solvent is too high and produces an undesirable condensation, even if on certain apparatus one tries to maintain a constant pressure drop by controlling the flow rate of extraction of used air as a function of this pressure drop, this regulation of the pressure drop being quite insufficient in the case of maximum concentrations of solYent.
Moreover, in certain applications to treatment lines, the increase of runningspeeds of the webs requires the des;gn of drying apparatus of greater and greater length, because then they are more economical, and consume less energy than short drying tunnels, but then there is a limit because the structure of the support for the nozzles at the operatins temperatures used, which can reach 300C, then has mechanical strength defects, twisting and curving under the effect of the thermal stresses.
In certain other apparatus, the fan and burner are disposed beneath and above the drying zone itself (which comprises the nozzles), with the ran downstream of the burner, and connected to the nozzles by a wedge-shaped chamber, which has the disadvantage that, if the flame blows through (because of a drop in air pressure or an ;ncrease in gaz pressure), i~ reaches the fan, which damages the fan and can even destroy it, besides which with such an arrangement, the fan pressure being related to air density, thus to its temperature which can vary from 120C to 33~C,sign;-ficant pressure variations can occur which are also unfavourable to the required uniformity of blowing and adequate support of the web. -Finally, the thermal energy consumption of these known appara-tus is very high, because of the high flow rates of used air (extracted), which moreover also requires the use of large upstream cleaners which also consume a lot of energy. This flow rate is due particularly to the entry of quantities of cold air through the inlet and outlet openings in the housing which cannot be reduced without risk of blocking the recycled air, loaded with solvents.
As for the side structure of the system, some known apparatus have a main hou6ing which only contains the nozzles and the means extrac-t,ng used air, whereas the .an and burr,er, wnich constitute the means for - reheating the air supply, are placed in a separate housing disposed on the side of the first ho~sing and connected to it by sleeves. It follows that this arrangement is difficult to adapt to the available space offered for the installation of the apparatus, and moreover prevents any extension of the apparatus required by an increase of speed.
In general, the installation of two drying tunnels "in lin ", even touching, has the disadvantage of not ensuring equal spacing of the nozzles at the interface zone, and consequent reliable web support.
Accordingly, the present invention has as object to avoid the various disadvantages of the known drying apparatus.
3L~ 7t;~3~ 4.
Thus, the invention provides an apparatus of the kind referred to, characterised in that, in the direction of movement of the web, the housing comprises at least two separate sections which are fixed together each section comprising a set of nozzles which comprises two rows of nozzles and a recycling fan whose input communicates with the inside volume of the housing and whose output is connected to said rows of nozzles through ducts provided with heat addition means connected to the source of heat.
Due to this arrangement, the complete housing of the apparatus which, for the high running speeds now required, especially on offset prin-ting rotors, has to have a considerable length, for example 7 m approxima-tely, is subdivided into a plurality of sections,for example two or three, or more if required, and they can even be juxtaposed indefinitely, since these sections are practically identical, except for those which also bear the common source of heat or the common extractor fan, thus making the structure perfectly modular and adaptable. If follow that the length of each section can be limited to a suitable value, for example of the order of 2,5 m for normal web sizes, or 3 m for small web widths (given that the wider the apparatus has to be because of the web widths to be treated, the more the number of sections in line can be increased, so as to reduce the flow rite to be produced on each recycling fan). Th;s subdivis;on of the housi~g thus enables each of its sect;ons to be guaranteed a su;table mechanical strength at the nozzles. The subdivision also, by enabling a regular spacing of the nozzles connected to the recycling fan of each section, improves the uniformity of blowing and the temperature distribution.
In particularly advantageous fashion, the distance between the last nozzle of one sect;on and the f;rst one of the next can be equal to the d;stance between the nozzles of a given section, which thus ensures a constant spacing of the nozzles from one end to the other of the hous-ing and avoids any interruption in the support of the web, so that no flapping of the web will appear on passing from one section to the next.
~ qore particularly, the present invention relates to an apparatus for simultaneously drying in hot air and supporting a continuous web of flexible material. The apparatus comprises a casing defining a web inlet opening and a web outlet opening for the web which travels through the inlet opening and the outlet opening in a general path longitudinally through the casing. Each supply means and exhausting means for exhausting used air from inside the casing are provided. The casing comprises at least two sections defining chambers in adjacent relation longitudinally of the casing, each section having an upper set of nozzles and a lower set of nozzles disposed respectively above and below the general path. Each section includes air recycling means having input means communicating with the inside of the casing and output means, duct means putting the output means in communication with the upper set of nozzles and the lower set of nozzles of the respective section and heat adding means for putting the heat supply means in communication with the duct means for adding heat from the heat supply means to the air recycled to the sets of nozzles by the output means of the recycling means.
"~
3L~'~t~ 5.
In a preferred embodiment of the invention,at least one end section of the housing can contain a burner which is associated with a combustion chamber.
In a particularly preferred embodiment of the invention, the source of heat can be provided by at least one burner disposed at the end of a combustion chamber presenting an inlet for recycled air connected to the output of a recycling fan, the inlet being situated upstream of the heat addition means for said ducts. This arrangement enables a mixture to be obtained in two stages, firstly dilution of the burner gas with air coming directly from the recycling fan associated with this burner, and secondly dilution with air sent by the same fan directly to the blower ducts, which gives greater flexibility in regulating the temperature and the pressure, and a more uniform temperature. Moreover, the positioning of the passages inputting heat to the blower ducts downstream of the recycling fan avoids any damage to or destruction of the fan.
Preferably the heat source can be common to at least two sections, the temperature of the air arriving at the nozzles of each sec-tion being regulable independently by dosing the heat input to each of the sections; in this way, for example, variable angle flaps can be disposed in the passages inputting heat to the blower ducts of at least one of the sections of the housing which enables the flow of burnt gas from the combustion chamber going to the different sections to be regulated, so as to obtain different temperatures in the sections and thus provide pro-gressive evolution of the heating of the moving web. These flaps can be controlled normally or automatically and, in the latter case, the flaps of one section can be connected to an automatic regulator device, itself connected to temperature pick-ups disposed in that section and in a juxtaposed section.
.
6.
In an embodiment, it can be arranged that the nozzles of a given sect;on of the housing are split into at least two groups which are connected to the supply means of combustion gas recycled air mixture by two temperature regulating means, which are separately controllable.
The section can be separated, by means of partitions, into at least two parts, a control flap being formed by the same number of separately con-trollable members, which enables blower temperatures which are different and controllable to be obtained in the same section.
Preferably the extractor fan can be situated inside the hous-10 ing of the apparatus, in which case only its drive motor is disposedoutside, which avoids having to provide a special frame disposed on the envelope, eliminates the connecting ducts which would be heat insulated, and above all deadens the noise of the fan.
In particularly advantageous fashion, each of the web inlet and outlet openings in the envelope is provided with two nozzles placed one above and one below, and which each present at least one air ejec-tion slit extending transversely relative to the direction of web move-ment and across the whole width of the web, these nozzles being connected to a source of a;r external to the envelope Gf the appara~us and which is associated with pre-heating means. In this way, these nozzles form curtains of air which obstruct the entry of outside air through the inlet and outlet openings, the air blown in the form of a curtain being taken from outside the housing and pre-heated, which eliminates the risk of condensation within the housing and also reduces the required extraction flQw. Preferably, the upper and lower nozzles of each of the inlet and outlet openings can each present two slits spaced apart in the direction of web movement, the space between the upper slits being offset and par-tially overlapping relative to the space between the lower slits.
This arrangement creates an additional node on the path of the web, at the inlet or outlet of the housing thus stabilising further 3l1'7~j~3~2 the web movement, particularly at its entry into the housing where it elilninates flapping which would lead to harmful contacts. Moreover, the creation of this additional node, adjacent the inlet or outlet opening, reduces practically to zero the play of the web in the opening, such that the height of the opening can be made minimal and reduce practically to zero the inflow of external air which might enter the housing through this opening (the flow being a function of the cross-sectional area of the passage presented and of the speed of flow, therefore of the diffe-rence in air pressure between the inside and the outside).
Conveniently, the external air source can comprise a fan for combustion air associated, as well, with the heat source, which avoids having to instal an additional air source and enables a reduction in energy consumption since, in normal operation, the burner only works at approximately one third of its power, the maximum power only being used during warm-up of the apparatus, while moreover there is no disadvantage in having a lower air pressure in the inlet and outlet nozzles during warm-up since there is not yet, in this phase any solvent passing through the apparatus which might produce condensation.
; Preferablyj again, the pre-heat.ng means can cnmprise a he~t exchanger situated in the combustion chamber of the burner of the appa-ratus which avoids using any additional source of pre-heat.
Thus the pre-heating means can be arra-nged to comprise a system for recovering heat from one of the two heat bearing elements consisting of the dried web and the air coming out of the extractor fan (with or without filtering of this air).
In a particular embodiment the external air source and the heat recovery system can be associated with a web cooler disposed at the output of the drying apparatus (the fan for burner combustion air can, for example, take air in from the hood of the web cooler).
3Ll'~t~ Z 8.
Preferably the control of the extractor fan flow can be connec-ted to an automatic regulat;on device, itself servo-ed both to an element measuring the pressure difference between the inside and the outside of the housing and an element for measuring a second parameter relating to the concentration of solvent occurring in the apparatus. This enables extraction to be reduced when the solvent concentration is low and to in-crease it when the concentration is high, this regulat;on being essential to avoid the undesirable condensation referred to above. The second para-meter used can comprise, for example, the rotor speed in the case of a press line, the power of the burner or again the concentration of oxygen in the housing or the solvent concentration itself in the extracted air.
Preferably, the longitudinal members bearing the nozzles com-prise tubes presenting air flow orifices which communicate with said nozzles and are open at their ends, so that a small part of the blown air penetrates these longitudinal members and ensures a uniform temperature.
Other features and advantages of the invention will appear from the following description, by way of non-limiting example, with reference to the acoompa~ying drawings in which :
: Fig. 1 represents an external perspective veiw of an apparatus according to a particular embodiment, in accordance with the invention, and comprising two sections;
Fig. 2 represents a diagrammatic view of this apparatus in vertical section in a vertical longitudinal plane of the apparatus;
Fig. 3 represents a perspective view of a blower according to a particular embodiment of the invention and including a saparation wall, Fig. 4 represents a.transverse section of the part of the apparatus through which passes the web;
Fig. 5 represents a detail from Fig. 4 according to a parti-cular embodiment of the invention.
.
~L1'~tj~4 ~ 9 The apparatus represented in the drawings is an apparatus for drying webs of printed paper coming from an offset printing line.
The apparatus comprises, mounted on a support consisting of feet 1, a closed envelope 2 which has a generally parallelopiped shape, comprising two vertical end faces 2a and 2b in each of which is formed an inlet ~3a) or outlet (3b) opening, in front of which is disposed a pair of nozzles 4a or 4b fixed outs;de on the end faces 2a and 2b, the two openings 3a and 3b defining a horizontal plane for movement of the web to be dried, the movement following a direction D extending horizon-tally from the inlet opening 3a towards the outlet opening 3b.
In succession in the longitudinal direction of the apparatus which forms the direction of movement D, thehousing comprises two separate sections comprising parallelopiped chambers 5a and 5b which are joined in a vertical plane 6 and are fixed together in this plane.
In the vertical direction, each of these sections 5a and 5b comprises two superposed chamber elements 7a and 7b, the lower chamber 7a forming the blower chamber, while the upper chamber 7b forms a reheating chamber, the elements being joined in a horizontal plane 8.
In each of the blower chambers 7a and 7b of the two sections 5a and 5b, are disposed two sets of nozzles 9c and 9d, disposed in two horizontal planes parallel to the average plane of the web B and placed at a small distance from this plane, for example 3 to 4 mm away. Each of the nozzles 9c or 9d comprises an elonsate bar extending transversely relative to the direction D, this bar being hollow and comprising, on its face towards the web B two parallel slits, transverse relative to the direction D and extending right across the width of the web B, these slits 10 being separated by a solid part which enables an air cushion to be created ensuring the support of the web B upwards or downwards.
The air bars 9c above the band B are disposed in alternation in the iongitudinal direction D with the lower bars 9d, of equal number, 6~2 lo.
so as to ensure equal spacing between the alternate bars with a pitch p.
The different nozzles 9c or 9d, disposed above or below the web are fixed to a collector or plenum llc or 11d which extends horizon-tally in the direction D along the whole set of associated elements, each collector communicating both with the air bars 9c and 9d and with a communication duct 12c or 12d, these ducts outputting into the collec-tors llc and 11d in the middle of the collectors lengthwise (although for clarity, the junction of the lower duct 12d has been displaced in the diagram to one end of the collector).
The same arrangement exactly is provided in the second section 5b of the envelope. The two upper collectors llc and the two lower col-lectors lld are positioned lengthwise, moreover, so that the same pitch p which separates the different nozzles of a given collector also separates the last nozzle 9d of the lower collector of the first section from the first nozzle of the upper collector of the second section thus ensuring perfect alternation of the air cushions fr~m one end of the housing to the other.
The lower collectors 11d are mounted in two parts telescopically sliding relative tQ each other in the vertical direction, with elastic seals 13 interposed between the shaped facing edges of the two component parts. The lower part of the lower collectors being fixed, their upper part which carries the air bars 9d can therefore be displaced vertically by a push rodard linka~e shown schematically at 14 and reacting against the housin~ itself. The mechanism 14 is controlled by a jack 15 which itself is supplied with compressed air 16 though a distributor 17. This enables the lower set of nozzles to be lowered either when the apparatus is shut down, for example for washing the plates, or during operation to avoid damage to the paper which, over-heated, would break and require the apparatus to be re-started, with a consequent considerable waste of time. The mechanism 14 supports the two longitudinal hollow tubular ~7~
members 18 which are disposed laterally, on opposite sides of the collectors 11d, and on which the nozzles 9d are fixed.
As shown more precisely in Fig. 4 and 5, each of the air bars 9c which communicates in its central part and by its its upper face with the upper collector or plenum llc, is also fixed and suspended at each of its two ends beneath one of the two hollow tubular members 18, which itself is suspended permanently from the envelope 2. Holes 19 are formed between these members 18 and the air bars 9c, so as to ensure that hot air penetrates inside the members 18 which are also open at their ends, this circulation of air ensuring, in this way, a uniform temperature. The same applies to the lower air bars 9d, which are fixed and carried in an exactly symmetrical fashion above other hollow tubu-lar members 18, fixed to a part 18a which can be displaced vertically using the mechanism 14. Holes 19 are also provided between the bars 9d and these members 18 to ensure a similar circulation.
Each pair of nozzles at the inlet 4a and outlet 4b presents a horizontal passage for the web B at the height of the inlet (3a) and outlet (3b) openings these horizontal passages 20 comprising nozzles consisting of slits transverse to the direction D, of which two are provided on each of the upper and lower faces of this passage, the two upper slits 21c being disposed alternately with the two lower slits along the hor;zontal direction D. These slits 21c and 21d are disposed at practically the same distance from the web B as the slits of the air bars 9c and 9d, and the slit 21d or 21c of each nozzle closest to the end wall 2a or 2b of the envelope is positioned as close as possible to the inlet opening 3a or to the opening 3a or 3b, this same slit 21c or 21d being also disposed at the same distance p from the closest air bar 9c or 9d inside. The air coming out of each of the slits 21c, 21d forms à curtain of air which separates the gases within the housing 2 from the external air. Moreover, the slits being disposed in pairs on opposite . ~
ti~4 ~
12.
sides of the hand, air cushions are formed which also maintain rodes of undulations in the path of the web B.
In each of the upper elements 7b of the two sections 5a and 5b, is a recycling chamber 22a or 22b, each of these chamberscommunica-ting with the outlet of a blower or recycling fan 23a or 23b which isfixed under the upper surface of the housing 2, so that only the drive motor 24 of each fan is disposed above the hous}~g. The two side ends of each of the chambers 22a or 22b are connected to vertical ducts 12c and 12b which output into the collectors llc and 11d.
In the outlet wall 2b of the hou~ing and at the level of the upper element 7b, a burner 24 is fixed which can be a mixed burner operating either on gaz or on fuel oil. Within the housing the torch of the burner which emits the flame 24a is surrounded with a certain gap 25, by a cylindrical combustion chamber, which extends from this burner as far as the front end of the blower chamber 22a. This combus-tion chamber 26 presents enlargedparts, at the level of the two blower chambers 22a and 22b, in the shape of hoods directed downwards and ; communicating through passages 27 with the vertical ducts 12c and 12d.
At the edges cf these pass~ges ?' are piv~cd control fa'ps 28 which enable the proportion between the recycled air coming from the fan 23a or 23b and the burnt gas coming from the combustion chamber to be varied.
In a particular embodiment, the control flaps 28 of the first section 5a are connected mechanically to a servo motor 29 which itself is connected electrically to a control device 30 receiving values given by two temperature pick-ups 31a and 31b disposed respectively in the two upper collectors llc. The control of the burner 24 is connected on one hand to a second temperature pick-up 32 disposed in the second section 5b or else to an infrared temperature detector 33 disposed downstream of the outlet block 4b. The input of combustionair for the burner 24 3L~ 7 6 ~3~2 13.
is connected to the output of a fan 34 which itself is fed from the hood of a cooler 44, disposed downstream ofthe drying apparatus, and through which the web B passes subse~uently.
On the p;p;ng supply;ng combust;on a;r to th;s burner, a second pipe 36 is connected which enters the combustion chamber 26, at the le~el of the chamber 22b and passes through this chamber to the other side so as to form a heat exchanger with this chamber, the pipe then subdividing to join the two inlet (4a) and outlet (4b) blocks in both their upper and lower parts.
The blower chamber 22b of the second section also communicates w;th a th;rd duct 37 wh;ch is bent round so as to house the combus-tion chamber in the vicinity of the burner and to communicate with the gap 25 left free round the burner so as to bring in recycled air at this po;nt.
Finally, between the two blower chambers 22a and 22b, there is provided an extractor fan 38 which ;s fixed under the upper wall of the housing 2 ;n similar fash;on to the fans 23a and 23b and which communicates w;th a chimney 39 venting to air. In the chimney ;s ;nter-posed a flap 40 for controlling the flow of air extracted which is con-trolled by a jack 41 receiving on one hand a signal com;ng from a regu-lation device 42 fed with air sensitive to the pressure drop within the housing and on the other hand a transm;tter 43 sensitive to the solvent concentration within the housing.
As shown m~re precisely ;n Fig. 3, the upper collector or plenum llc has the shape of an elongate parallelopiped chamber w;th a wedge-shaped end, that is to say a chamber whose cross-section ;n a vertical plane parallel to the direction of web movement D is a trapeze.
The alr bars 9c are fixed underneath and across the whole width of this chamber. Above this chamber, and across a part only of ;ts width, is disposed the duct 12c which, conversely, extends along the whole lensth ~ 4 ~ 14.
of the upper face of the plenum llc. At its upper end, this duct 12c com-municates with another feed chamber 22a, which extends over the same length as the duct in the direction D, which projects from it transver-sely (in the direction of the air bars 9c) and within which is disposed the recycling fan 23a. Within the blower duct 12c, is disposed a vertical partition 44 extending transversely, this partition being extended by a further partition 44a which also extends transversely over the whole w;dth of the collector 11_~ but is inclined generally parallel to one of the duct 12c are mounted, pivoting about a horizontal axis X-X, parallel to the direction of web movement D, two control flaps 28, 28' disposed on opposite sides of the partition 44 in this section of this duct 12c.
There are thus two air currents which pass on opposite sides of the partitions 44 and 44a to reach the group of air bars 9c positioned in front of the partition 44a and to reach the group behind it.
It should be noted lastly that it can be arranged for each section of the housing to contain two housing elements disposed in relation to each other above, below or beside, in any case transversely rel~tive to the direction of web movement, these elements comprising one the blower zone and the other the reheating zone, which presents a great flexibility of adaptation as a function of the space available or of any desired lateral extension of the apparatus. The reheating element of each section can be positioned remote from the blower element, in which case a third element establishes the connection between these two.
Claims (14)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Apparatus for simultaneously drying in hot air and supporting a continuous web of flexible material, said apparatus comprising a casing (2) defining a web inlet opening (3a) and a web outlet opening (3b) for said web which travels through said inlet opening and said outlet opening in a general path (D) longitudinally through said casing, heat supply means (24), exhausting means (38) for exhausting used air from inside said casing, said casing comprising at least two sections (5a, 5b) defining chambers in adjacent relation longitudinally of said casing, each section having an upper set (9c) of nozzles and a lower set (9d) of nozzles disposed respectively above and below said general path (D), each section including air recycling means (23a, 23b) having input means communicating with the inside of the casing and output means, duct means (12c and 12d) putting said output means in communication with the upper set of nozzles and lower set of nozzles of the respective section and heat adding means (27) for putting said heat supply means (24) in communication with said duct means for adding heat from said heat supply means (24) to the air recycled to said sets of nozzles by said output means of said recycling means.
2. Apparatus as claimed in claim l, wherein said heat supply means comprises at least one burner (24) in a combustion chamber (26), said combustion chamber having an input connected to receive recycled air from at least one of said recycling means, said input of said combustion chamber being upstream of said heat adding means (27) relative to the respective recycling means (23b).
3. Apparatus as claimed in claim 1, wherein said heat supply means is a single supply means and said heat adding means (27) includes control means (28) for controlling independently the heat supplied from said supply means (24) heat to different ones of said sections (5a, 5b), whereby to control independently the air temperature at the nozzles of the different sections.
4. Apparatus as claimed in claim 3, wherein said control means includes means (28, 28') for controlling independently the heat supplied from said heat supply means (24) to different groups of nozzles in the same section.
5. Apparatus as claimed in claim 1, wherein said exhaustion means includes a fan (38) disposed within said casing (2) and motor means disposed outside said casing.
6. Apparatus as claimed in claim 1, wherein upper and lower nozzle means (4a, 4b) are disposed outside said casing (2) adjacent both said web inlet and outlet openings above and below the web path (D) and define slits (21c, 21d) extending across the web path for blowing air onto said web, the apparatus including means (36) for heating external air and supplying it to said nozzle means (4a, 4b) outside said casing.
7. Apparatus as claimed in claim 6, wherein each of said upper and lower nozzle means (4a, 4b) outside said casing, comprises two said slits (21c, 21d) spaces along the web path (D), the spaces between the upper slits (21c) being offset from and overlapping the spaces between the lower slits (21d).
8. Apparatus as claimed in claim 6, comprising fan means (34) for supplying external air both to said heat supply means (24) and to said means (36) for heating external air.
9. Apparatus as claimed in claim 6, wherein said means for heating external air comprises heat exchange means (36) for receiving heat from said heat supply means.
10. Apparatus as claimed in claim 6, wherein said means for heating external air comprises means for recovering heat from the dried web issuing from the casing.
11. Apparatus as claimed in claim 10, wherein said means for recovering heat from the dried web includes cooling means (44) for cooling the dried web.
12. Apparatus as claimed in claim 6, wherein said means for heating external air comprises means for recovering heat from the outlet of said exhausting means.
13. Apparatus as claimed in claim 1, wherein said web carries a solvent and means (43) are provided for sending the solvent concentration in the atmosphere within said casing and are connected to said exhausting means for controlling said exhausting means, said exhausting means (38) also including control means (40, 41, 42) sensitive to the pressure difference between the inside and the outside of said casing for controlling the flow through said exhausting means.
14. Apparatus as claimed in claim 1, comprising longitudinal members (18) carrying said nozzles (9c, 9d), said longitudinal members forming tubes defining orifices for the passage of air which communicate with said nozzles and being open at their ends.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP81400830.6 | 1981-05-25 | ||
| EP81400830A EP0066661B1 (en) | 1981-05-25 | 1981-05-25 | Apparatus for drying webs by hot air while simultaneously supporting the material, e.g. for paper webs delivered by a printing machine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1176842A true CA1176842A (en) | 1984-10-30 |
Family
ID=8188524
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000388641A Expired CA1176842A (en) | 1981-05-25 | 1981-10-23 | Apparatus for hot air drying and simultaneously supporting continuous webs, particularly printed paper webs |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0066661B1 (en) |
| JP (1) | JPS57196077A (en) |
| AT (1) | ATE24606T1 (en) |
| CA (1) | CA1176842A (en) |
| DE (2) | DE66661T1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5364651A (en) * | 1991-08-21 | 1994-11-15 | Buehler Ag | Process and apparatus for pressing and drying pasta |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL8800226A (en) * | 1988-01-29 | 1989-08-16 | Stork Contiweb | DRYER FOR A MATERIAL TRACK. |
| DE4105559C1 (en) * | 1991-02-22 | 1992-09-17 | Heidelberger Druckmaschinen Ag, 6900 Heidelberg, De | |
| NL9300199A (en) * | 1993-02-01 | 1994-09-01 | Stork Contiweb | Dryer with short restart. |
| FI943115A (en) * | 1994-06-29 | 1995-12-30 | Valmet Paper Machinery Inc | Arrangement for attenuation of sound level at the cooling layer of a cellulose dryer |
| DE19623303B4 (en) * | 1996-06-11 | 2005-08-11 | Deppe, Oliver, Dipl.-Ing. | Apparatus for drying material webs with fresh air preheating, optionally with compact circulating air blowers and guide nozzle stations |
| US6108941A (en) * | 1999-07-22 | 2000-08-29 | Aeroglide Corporation | Conveyor dryer with stationary conveyor support structure |
| JP5615020B2 (en) * | 2010-04-08 | 2014-10-29 | 株式会社大川原製作所 | Drying equipment with continuous box dryer |
| FR2967486B1 (en) * | 2010-11-17 | 2014-10-24 | Mihnea Serban Nicolas Teculescu | METHOD AND INSTALLATION FOR INCREASING PRODUCTION CAPACITY AND REDUCING ENERGY CONSUMPTION DURING HEATING OR DRYING OF VARIOUS PRODUCTS |
| CN105486055A (en) * | 2016-01-04 | 2016-04-13 | 安徽汇展热交换系统有限公司 | Air drying device for copper radiator |
| CN108995369B (en) * | 2018-06-17 | 2020-08-07 | 河源市博越彩色印刷有限公司 | Method for drying printing ink and drying metal disc |
| CN114508921A (en) * | 2022-03-04 | 2022-05-17 | 广德和美印务科技有限公司 | But plastic bag processing is with drying equipment of angle modulation |
Family Cites Families (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2952078A (en) * | 1953-11-30 | 1960-09-13 | Cyril A Litzler | Apparatus for controlled heating and cooling of continuous textile material |
| FR1273507A (en) * | 1960-10-14 | 1961-10-13 | Method and device for producing a determined moisture content in mixtures of plastics intended in particular for the manufacture of ceramic parts | |
| DE1299667B (en) * | 1965-01-20 | 1969-07-24 | Trockentechnik Kurt Brueckner | Device for the thermal treatment of a moving flat web of material |
| US3448526A (en) * | 1967-07-20 | 1969-06-10 | Horace L Smith Jr | Apparatus for and method of drying ink and other materials on a carrier |
| DE1900287A1 (en) * | 1969-01-03 | 1970-07-30 | Heurtey Sa | Thermal treatment of paper and metal strips and - painted metal |
| US3587177A (en) * | 1969-04-21 | 1971-06-28 | Overly Inc | Airfoil nozzle |
| US3577653A (en) * | 1970-01-20 | 1971-05-04 | Beloit Corp | Web drying tunnel |
| GB1341095A (en) * | 1970-06-09 | 1973-12-19 | Midland Ross Corp | Conveyor system |
| US3946501A (en) * | 1971-02-10 | 1976-03-30 | E. T. Marler Ltd. | Drying apparatus |
| JPS5615012Y2 (en) * | 1971-08-06 | 1981-04-08 | ||
| FR2151230A5 (en) * | 1971-08-20 | 1973-04-13 | Stumm Eric | |
| US3739491A (en) * | 1971-09-22 | 1973-06-19 | Tec Systems | High velocity air web dryer |
| BE791511A (en) * | 1971-11-19 | 1973-03-16 | Flynn Charles S | RAPID THERMAL TREATMENT OF A BAND OF MATERIAL |
| AU511678B2 (en) * | 1977-08-29 | 1980-08-28 | Airco Inc. | Recovering solvents from drying ovens |
| FR2406172A1 (en) * | 1977-10-17 | 1979-05-11 | Leino Ilkka | Veneer sheets etc. drying system - has shutter regulating air discharged to give predetermined depression in drying chamber (SF 30.11.77) |
| GB1583199A (en) * | 1977-12-01 | 1981-01-21 | Whiteley Ltd E Gordon | Cloth drying apparatus |
-
1981
- 1981-05-25 EP EP81400830A patent/EP0066661B1/en not_active Expired
- 1981-05-25 AT AT81400830T patent/ATE24606T1/en not_active IP Right Cessation
- 1981-05-25 DE DE198181400830T patent/DE66661T1/en active Pending
- 1981-05-25 DE DE8181400830T patent/DE3175767D1/en not_active Expired
- 1981-10-23 CA CA000388641A patent/CA1176842A/en not_active Expired
-
1982
- 1982-01-21 JP JP57008242A patent/JPS57196077A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5364651A (en) * | 1991-08-21 | 1994-11-15 | Buehler Ag | Process and apparatus for pressing and drying pasta |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0066661B1 (en) | 1986-12-30 |
| JPH0310870B2 (en) | 1991-02-14 |
| EP0066661A1 (en) | 1982-12-15 |
| DE66661T1 (en) | 1984-07-19 |
| ATE24606T1 (en) | 1987-01-15 |
| JPS57196077A (en) | 1982-12-01 |
| DE3175767D1 (en) | 1987-02-05 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |