GB2192700A

GB2192700A - Infrared web drier

Info

Publication number: GB2192700A
Application number: GB08710899A
Authority: GB
Inventors: Manfred Pabst
Original assignee: A Monforts GmbH and Co
Current assignee: A Monforts GmbH and Co
Priority date: 1986-05-09
Filing date: 1987-05-08
Publication date: 1988-01-20
Anticipated expiration: 2007-05-08
Also published as: FR2598495A1; JPS62268982A; GB8710899D0; DE3615728C2; IT8720233A0; DE3615728A1; GB2192700B; IT1203955B; FR2598495B1

Abstract

Infra-red dryer which can be heated by gas or electricity. Changing from one type of energy to the other can be effected very rapidly. A product band 1 passes vertically through a working duct 4 equipped with heating walls 6 which are parallel to the surface of the product band and equipped with radiators 8 which can be removed from the working duct 4 or replaced in the latter, individually or as a group, on each occasion by pivoting about an axis 7 parallel to the surface of the heating wall 6. Air is admitted in the vertical direction of the duct 4. Each of the radiators 8 has a radiation surface heated by gas 11 and a radiation surface heated electrically 12. The radiation surfaces of each radiator 8 are interchangeable on the heating wall 6 by pivoting about the axis 7. <IMAGE>

Description

SPECIFICATION Infrared drier This invention relates to an infrared drier (IRdrier), comprising a vertical working shaft for the pulling through of an extended textile fabric web, in which drier the working shaft has a width at least equal to that of the fabric web to be treated, which possesses, as a component of the heating walls disposed parallel to the fabric web surface, radiator bodies which can be pivoted singly or in groups each about a radiator axis orientated parallel to the surface of the heating wall out of the working shaft and back again, and which is equipped with an air extraction in the vertical longitudinal direction of the shaft.

Infrared driers of the aforementioned type are described in German Patent Application S 22 990/82a, 34, published on 30 December 1954. In this apparatus, in order to prevent scorching of the material to be treated, the radiators are arranged to be pivotal between two limiting positions in such a manner that the emitted radiant energy is directed away from the material to be treated in the waiting position, which is different from the working position. The radiators are switched off when pivoted away, because according to the orientation of the radiators in the waiting position, if the heating power were switched on, the adjacent radiators or the surroundings of the machine would be unacceptably heated up.When the machine is started up again, therefore, the acceleration of the fabric web must be adapted to the rate of heating up of the radiators, if a uniform treatment result is required.

Infrared driers according to German Patent Application S 22 990/82a, 34 or according to DE-OS 14606 660 can be designed in principle for heating either with electrical current or with combustible gas. In general, the infrared drier is initially so constructed that it requires for operation the type of energy most favourable at the location. At certain times of the day or seasons of the year and in different countries, the costs for different forms of energy vary so drastically with time that it may pay to heat the infrared drier, when gas costs are favourable, with this type of energy and to heat it electrically when electrical costs are favourable. This presupposes, however, considerable investment and/or installation work for the replacement or exchange of the entire machine or at least of important components of the machine.

The objective of the present invention is to create an infrared drier which can be heated as desired with gas or by electricity and in which the change of the type of energy can be carried out virtually while the machine is running. The solution according to the present invention consists, in the infrared drier of the initially named type having radiator bodies pivotally mounted in the relevant heating wall, in that each of the radiator bodies possesses a gas-heated and an electrically-heated radiator surface and that the radiator surfaces of each radiator body are interchangeable at the heating wall by pivoting about the radiator axis.

By the invention the result is achieved that the type of energy used for heating can be changed while the machine is running by pivoting the radiator bodies. The pivoting can be carried out instantaneously, because the radiator surface to be charged with the new form of energy can already be preheated outside the working shaft and therefore immediately emits the radiant energy required for operation when it is pivoted into the working shaft. A further advantage of the invention lies in the fact that the radiator body can be so designed and pivotally mounted that when the machine stops (with the fabric web stopped) the radiator surface at that time just in operation can be pivoted out of the working shaft, in order to prevent overheating or burning of the goods undergoing treatment.

According to a further aspect of the invention, it may be favourable for the pivoting and interchanging of the radiator surfaces and, possibly, the pivoting-out of the two radiator surfaces from the working shaft, if the mean directions of radiation of the two radiator surfaces are at an angle of about 1800 or about 90" to each other. This means, for the pivoting movement, that the radiator surfaces should be interchangeable at the heating wall in the working shaft by a 90" or a 1800 pivotal movement.

Each radiator body should preferably possess at least one third wall, which can be brought by a further pivoting, for example of 90 , into the heating wall, but does not possess heating means. This "cold" surface is preferably pivoted into the working shaft when a stopping of the fabric web conveying takes place.

In order to achieve the result that the radiator surfaces, even in the pivoted-out waiting position, can radiate with full energy for preheating or for the fading-out of a previous heating, without risk of damage to the environment or the adjacent radiator, according to a further aspect of the inyention an outer shaft running generally parallel to the working shaft is provided externally at each heating wall surface, the radiator surfaces being directed into this shaft during preheating or fading out of heating.

For removing the energy thus released, it is furthermore advantageous if means for switching-over the air extraction to the shaft which contains the radiator surfaces last heated before the pivoting motion are associated with the outer shaft and the mechanism for carrying out the pivoting. Preferably, the drive for switching-over the air extraction is coupled with the means for pivoting-over the radiator bodies. In particular, the construction shall be such that the radiator bodies, when the fabric web is stopped, are automatically pivoted out of the working shaft and, when the machine starts up again, the radiator bodies or preheated radiator surfaces are pivoted back again into the working shaft, in such a manner that the radiator surfaces immediately radiate with full energy on starting up again and therefore the machine can be set in operation at its full speed.

Details of the invention are explained with reference to the schematic illustration of examples of embodiment thereof. The Figures show: Figure 1 a vertical section through an infrared drier comprising radiator bodies having two different radiator surfaces, oriented away from each other; and Figure 2 a partial section through an infrared drier comprising radiator bodies which possess radiator surfaces which can be interchanged by a 90" pivotal movement.

Fig. 1 shows a combined gas-electric-infrared predrier in section perpendicular to the plane of a fabric web 1 to be dried. This web is pulled in the direction of arrow 2 substantially vertically upwards, for example out of a squeezer mechanism 3, through a vertical working shaft 4 and is fed via a guide roll 5 to further treatment. The surfaces of the working shaft 4 lying parallel to the surface of the fabric web 1 are constructed as heating walls 6, into which there are integrated radiator heaters, generally referenced 8, pivotal singly or in groups through at least about 90" about a radiator axis 7 lying parallel to the surface of the heating wall 6.An air extraction system comprising suction chests 9 for extracting air drawn in at the lower end of the working shaft in the direction of arrow 10, is also associated with the working shaft 4.

Each of the radiator bodies 8 possesses a gas-heated radiator surface 11 (gas radiator) and an electrically heated radiator surface 12 (electrical radiator). By pivoting each radiator body 8 through 1800 about the radiator axis 7, the gas and electric radiators 11, 12 can be interchanged at or in the heating wall 6 according to Fig. 1.

According to a further embodiment of the invention, an outer shaft 13, orientated generally parallel to the working shaft 4, adjoins externally each heating wall 6. The outer shafts 13 are so equipped with an additional or switchable-over suction system that surfaces of the gas or electric radiators 11, 12 pivoted out from the working shaft can allow their heat to die away or be further operated at full energy in the region of the outer shaft after shutting off, without parts of the machine being adversely affected. For this reason, the suction chests 9 should be capable of being connected optionally or additionally to the outer shafts 13 also, so that the direction of inward suction can take place either through an inlet 14 at the base of the working shaft 4 in the direction of arrow 10 or via a suction hole 15 at the base of the outer shaft in the direction of arrow 16.For example, there may be associated with the mechanism for carrying out the pivoting movement of the radiator bodies 8, means for switching over the air extraction to this shaft 4 or 13 which, as the case may be, contains the radiator surface last heated before the pivoting movement.

In a further form of construction it may also be favourable, in the example of embodiment according to Fig. 1, to provide in addition to the pivotal movement through 1800 also a pivotal movement through 90" about the radiator axis 7. By such a 90" pivoting, if a stoppage of the fabric web occurs, the risk of excessive drying or burning of the goods is eliminated, since even a decaying radiation of the radiator bodies 8 is no longer directed into the working shaft 4 but into the adjacent, outer shaft 13. It is particularly to be recommended in this case to switch the extraction at full power to the outer shafts 13.Furthermore, the radiator surface necessary for continuing operation of the infrared drier (after the machine has started up) can already be preheated to full output while in the outer shaft 13, that is before pivoting-in into the working shaft 4. For brief machine stoppages, the relevant radiator surface may also be supplied unchanged with energy, while it is temporarily pivoted into the outer shaft 13.

In the example of embodiment according to Fig. 1, the radiator surfaces of each radiator body 8 are situated in mutually parallel planes.

The directions of radiation of the gas radiator 11 and of the electric radiator 12 are therefore at 1800 to each other. For replacing the one by the other radiator surface, a pivotal movement of 1800 is required. In the example of embodiment according to Fig. 2, the surfaces of the gas radiator 11 and of the electric radiator 12 are approximately perpendicular to each other, so that the directions of radiation are at an angle of 90" to each other and a pivoting angle of 90" about the radiator axis 7 is sufficient for switching over from the one to the other type of energy.

The radiator bodies 8 can, according to Fig.

2, be equipped also with cold surfaces 17, which complete the surfaces of the gas radiator 11 and electric radiator 12 to a column having, for example, a square or triangular cross-section, in such a manner that, if the fabric web stops, the gas and electric radiators 11, 12 can be pivoted out of the working shaft 4 into the adjacent outer shaft 13 and at the same time the heating wall 6 in closed by the cold surfaces 17. In other respects, in Fig.

2, one half of a combined gas-electric-infrared drier is schematically illustrated, the details of which correspond to those of the apparatus according to Fig. 1.

Claims

1. Infrared drier, comprising a working shaft (4) for the vertical passing through of an extended textile fabric web (1), in which drier the working shaft (4) has a width at least equal to that of the fabric web (1) to be treated, which comprises, as a component of the heating walls (6) disposed parallel to the fabric web surface, radiator bodies (8) pivotal singly or in groups each about a radiator axis (7) lying parallel to the surface of the heating wall out of the working shaft (4) and back again, and which is equipped with an air extraction in the vertical longitudinal direction of the shaft, characterized in that each of the radiator bodies (8) possesses a gas-heated (11) and an electrically-heated (12) radiator surface and that the radiator surfaces of each radiator body (8) are interchangeable at the heating wall (6) by pivoting about the radiator axis (7).

2. Infrared drier according to Claim 1, characterized in that the mean radiator directions of the two radiator surfaces (11, 12) make an angle of approximately 180 or approximately 90 with each other.

3. Infrared drier according to Claim 1 or 2, characterized in that the radiator surfaces are interchangeable at the heating wall (6) by a 90" or a 180 pivoting movement.

4. Infrared drier according to one or more of Claims 1 to 3, characterized in that an outer shaft (13), orientated generally parallel to the working shaft (4), adjoins each heating wall (6) externally.

5. Infrared drier according to Claim 4, characterized in that means for switchingrover the air extraction to the shaft (4, 13) which contains the radiator surface (11, 12) last treated before the pivoting on each occasion are associated with the mechanism for carrying out the pivoting movement.

6. Infrared drier according to Claim 5, characterized in that the drive means for switching-over the air extraction are coupled with the means for pivoting the radiator bodies (8).

7. Infrared drier according to one or more of Claims 1 to 6, characterized by drive means which automatically pivot the radiator surfaces (11, 12) just heated out of the working shaft (4) when the fabric web is stationary, and which automatically pivot these radiator surfaces (11, 12) back again when the machine is again started up.

8. Infrared drier according to Claim 7, characterized in that means for preheating the radiator surface (11, 12) to be pivoted next into the working shaft (13) are associated with the pivoting mechanism.

9. Infrared drier as claimed in Claim 1, sub stantially as described with reference to Fig. 1 or Fig. 2 of the accompanying drawings.