PLANT FOR DRYING SANITARY APPLIANCES AND MOULDS THEREOF

Abstract: A plant for drying sanitary appliances and moulds thereof, comprising a workbench (1) on which the various pieces to be dried are placed, characterized by comprising on said bench a retractable tunnel (11) formed with a double wall (18, 2) of substantially flexible material, which communicates with a drying air generator (21) and of which the inner wall (18) comprises a plurality of apertures (19) for the outflow of said air, means (9) being provided for unfolding it over said bench (1) after the moulding of the pieces, and for retracting it on termination of drying to enable the next cycle to be effected.

Description: Plant for drying sanitary appliances and moulds there This invention relates to a plant for drying sanit appliances and moulds thereof. In the ceramic industry, the production of gene sanitary appliances involves an initial stage in which fluid ceramic mix (slip) is cast into suitable moul generally of plaster, which reproduce in negative form outer shape of the appliance to be obtained. A certain t following casting, the mould has absorbed a certain quant of water from the mix, which has thus formed a surface cr while leaving fluid still in the interior, this fluid t being discharged. After a certain period of rest, required for the mix lose further water, the hollow article, now solid, is fed the glazing and firing stage. This traditional method, which can be either manual automatic, has however considerable limits. Curren ly, the production of an ar icle involves absorption by the mould of a considerable quantity of wat which has to be disposed of by a drying cycle. This dry cycle means that the mould is unusable for approximately day, making the continuous production of sanitary applian impossible ithout using a rapid drying process. Such process cannot be implemented in practice in that environment in which the moulds are dried is the sa environment in which the sanitary aplianσes are dried, whi latter drying has to be extremely slow to prevent t formation of cracks, which would lead to an unacceptabl increase in the number of rejects- There is therefore the problem of reconciling these t opposing requirements, namely the need to rapidly dry t moulds as soon as they have been used and the need to slowl dry in the same environment the sanitary appliances extracte from these moulds. To reconcile these opposing requirements it has bee proposed to feed the moulds through a drying oven, but thi solution has been found to be impracticable, as the personn has to be able to work around the moulds and would be unabl o withstand the serious environmetal conditions existing i a drying tunnel . The problem is solved according to the invention by plant for drying sanitary appliances and moulds thereo comprising a workbench on which the various pieces to dried are placed, characterised by comprising on said bench retractable tunnel formed with a double wall of substantiall flexible material, which communicates with a drying a generator and of which the inner wall comprises a plurali of apertures for the outflow of said air, means bei provided for unfolding it over said bench after the mouldi of the pieces, and for retracting it on termination of dryi to enable the next cycle to be effected, A preferred embodiment of the invention is descri hereinafter by way of non-limiting example with reference the accompanying drawings in which: Figure 1 is a schematic partial side view of a drying pl according to the invention in its rest state; Figure 2 is a plan view thereof; Figure 3 is a front view thereof on the line 111—111 Figure 1 ; Figure 4 is a vertical section therethrough on the line IV- of Figure 1 ; Figure 5 shows it in the same view as Figure 1 , but in working state; Figure 6 is a plan view thereof in the working state; Figure 7 is a front view thereof on the line VII-VII Figure 5; and Figure β is a vertical section therethrough on the line VI VIII of Figure 5; As can be seen from the figures, the drying pl according to the invention is applied to a traditio sanitary appliance casting line, comprising a bench 1 which are positioned a plurality of moulds 2 provided with plug 3 for forming the internal part of the article. As the bench 1, the series of moulds 2, the plugs 3 a the frame for their lifting are of traditional type and not form part of the invention, they will not be furth described. The description of the bench which will follow al relates to a line for drying the obtained sanita app1iances. In a position above the bench 1 there is provided overhead frame, indicated overall by 4 and comprising a pai of longitudinal rails 5 along which a plurality of carriag 6 can slide, supporting and guiding a like number of vertic r jb frames 7, each comprising two uprights 8 suspended fr the respective carriages 6, and a cross-member 8' connecti the two uprights of each rib frame together at their midd point . On of the two end rib frames, namely that positioned the end of the overhead frame 4, is fixed to the rails whereas the other rib frame, ϊe that facing the bench 1, provided with means for driving it along the rails. The drive means can be independent motors applied to t carriages 6, or a pair of endless cables extending along t entire length of the rails 5 and operated by a sing electric motor 9. The rib frames 7 are connected together by flexib cables 10 which enable them to be brought into mutual conta while limiting the maximum distance between them. The plant according to the invention also comprises tunnel, indicated overall by 11 and comprising two sidepiec 12 and a roof 13- It is constructed of fireproof plasti material substantially impermeable to air, such as PVC Both the sidepieces 12 and the roof 13 of the tunnel comprise pockets 14, through which the cross-member 8' a the lower part of tha uprights 8 of each rib frame 7 can inserted, to support the tunnel . Both the sidepieces 12 and the roof 13 of the tunnel comprise two walls, which are sealed together longitudinal along the edges 15 and also along intermediate lines 17 form longitudinal compartments 17 which can be inflated, which their inner wall 18 assumes an inwardly convex sha This inner wall comprises a plurality of apertures 19, t purpose of which, as will be apparent hereinafter, is direct air into the tunnel in different directions towa the moulds 2 when the compartements 17 are inflated. The roof 13 of the tunnel 11 also comprises aperture 19' in the outer wall 20. At one end of the tunnel 11, namely the end distant fro the bench 1, there is a ventilation system comprising a fa unit 21, a heat exchanger bank controllred by a control valve and equipment for connecting the fan to the interspace of th tunnel 11. The entire plant is controlled by a microprocesso which controls the drying cycle. The operation of the plant according to the invention i as follows: during the casting of the mix into the moulds 2, th formation of the thickness, the discharge of the interna fluid part of the mix, the raising of the plugs 3 and th removal of the articles from the moulds 2, the tunnel 1 remains gathered at the end of the bench 1 close to th ventilation system. After the articles have been removed from the moulds th electric motor 9 is powered to cause the first rib frame 7 t slide along the rails 5 and the tunnel 11 to unfold over th bench 1 because of the flexible cables 10 which connect th adjacent rib frames together. Uhen this unfolding is complet the ventilation system is powered to feed a jet o conditioned air into the longitudinal compartments 17 of th tunnel 11, and from here through the apertures 19 and on the moulds 2- Because of the convex shape of the compartmen 17 the drying air strikes the moulds 2 from sever directions, resulting in their rapid and complete dryin Again, because of the fact that apertures 19' are al provided in the outer wall 20 of the roof 13, the drying a jets also reach the plugs 3 which are suspended above t relative moulds 2, outside^the tunnel 11. Uhen drying is complete the ventilation system is halt and after deflating the compartments 17 the tunnel 11 gathered to the end of the bench 1 to allow repetition of t working σyσ1e. The drying cycle can also be effected without removi the sanitary appliances from the moulds, but simply openi the moulds, so that the appliances can also be subjected an initial drying stage. To enable the shape of the tunnel 11 to be adapted the shape and dimensions of the moulds 2, the distan between the rails 5 can be adjusted to enable the width the tunnel 11 to be increased, for which purpose the cros members 8' are of telescopic construction, and in additi can also be moved along the respective uprights 8 to incre the height of the tunnel- In both cases the system f fitting the tunnel 11 to the rib frames 7 by means of pocke 14 enables the material forming the tunnel to adapt to i dimensions. From the aforegoing it is apparent that the drying pla according to the invention has numerous advantages, and partiσular: - it enables each mould 2 to be used for several cycles (fo or even more) per day, so considerably increasing li productivity; - it enables the drying of the articles to be improved wi fewer rejects, because of the fact that the extern temperature can be maintained lower as it is no long related to the higher temperature normally used in ord not to excessively delay the mould drying process; - it enable the sanitary appliance production to multiplied, so substantially reducing the spa requirements of the overall installation and the un applianσe cost ; - it considerably reduces the construction cost of the enti production plant; - it substantially reduces energy consumption, both becau of the reduced air volume to be treated and because of t elimination of the thermal cycles to which the air w previously subjected.

Claims: C L A I M S 1. A plant for drying sanitary appliances and moul thereof, comprising a workbench (1) on which the vario pieces to be dried are placed, characterised by comprising said bench a retractable tunnel (11) formed with a doub wall (18,2) of substantially flexible material, whi communicates with a drying air generator (21 ) and of whi the inner wall (18) comprises a plurality of apertures (1 for the outflow of said air, means (9) being provided f unfolding it over said bench (1) after the moulding of t pieces, and for retracting it on termination of drying enable the next cycle to be effected. 2. A plant as claimed in claim 1, characterised comprising above the bench (1) an overhead frame ( comprising a pair of longitudinal rails (5) for guiding plurality of rib frames (7) for supporting said tunnel (11). 3- A plant as claimed in claim 2, characterised in th each rib frame (7) comprises two uprights (8) suspended fr carriages (6) slidable along said rails (5), and a cros member (8*) supported by said uprights (8). 4. A plant as claimed in claim 3, characterised in that t tunnel (11) externally comprises a plurality of transver pockets (14) through which the uprights (8) and cross-memb (8') of said rib frames (7) are inserted- 5- A plant as claimed in claim 2, characterised in that longitudinal rails (5) are of adjustable distance apart the frame (4), and the cross-member (8') of the rib fra (7) is of telescopically adjustable length. 6 . A plant as claimed in claim 3, characterised in that cross-member (8 1 ) of each rib frame (7) is of adjusta position along the uprights (8). 7. A plant as claimed in claim 1, characterised in that two walls (18,2) of the tunnel (11) are joined together by plurality of longitudinal weld lines to define a plurality inflatable longitudinal compartments (17). 8. A plant as claimed in claim 1, characterised in that outer wall (20) of the roof (13) of the tunnel (11) a comprises a plurality of aperture (19') for the outflow drying air. 9. A plant as claimed in claim 1, characterised in that rib frames (7) are connected together by flexible cables ( which enable them to be brought into mutual contact at t end of the rails (5) close to the air generator (21), wh limiting the maximum distance between them. 10. A plant as claimed in claim 2, characterised in t cables operated by an electric motor (9) are associated w the tunnel (11) to drive the carriages (6) of the rib fram (7) in the directions for unfolding and folding said tunn (11).

Inventors: LORA FERNANDO, LORA, FERNANDO
Applicants: PROGETTI S R L, PROGETTI S.R.L.
Application year: 1991
Main classification: C04B33
IPC codes: B28B11, C04B33, F26B9, F26B21, F26B25, F27D13