WO1999020853A1

WO1999020853A1 - Device for heating or drying surfaces

Info

Publication number: WO1999020853A1
Application number: PCT/NL1998/000606
Authority: WO
Inventors: Hans Van Rij
Original assignee: Hans Van Rij
Priority date: 1997-10-22
Filing date: 1998-10-22
Publication date: 1999-04-29
Also published as: AU9766398A; NL1007331C2

Abstract

The invention relates to a device for heating and/or drying surfaces, such as walls, floors or ceilings. The device according to the invention comprises a burner (2) and flexible lateral sealing members (4) which surround the burner and which, in conjunction with the surfaces to be dried, form the boundary of a heating space (5). The burner (2) is provided with an air-permeable flame carrier (3) for distributing a flame over the heating space (5). By means of an air feed device, such as a fan (21), an air/gas mixture is blown through the flame carrier (3) to the heating space (5), from which the combustion gases can escape under the flexible sealing members (4). During this process, a pressure build-up takes place in the heating space (5), with the result that an upward force is exerted on the device. Preferably, the flame carrier (3) comprises a ceramic foam. With the aid of the device, a quick and efficient drying of surfaces can take place, relatively little steam being produced.

Description

Device for heating or drying surfaces

The invention relates to a device for heating and/or drying surfaces, such as walls, floors or ceilings, comprising a burner, a gas feed connected to the burner, lateral sealing members which surround the burner and which, in conjunction with a surface to be dried and/or heated, form the boundary of a heating space, the burner comprising an air-permeable flame carrier for distributing a flame over the heating space, and also an air feed device, connected to the flame carrier, for feeding an air flow to the flame carrier.

In the construction of dwellings, a delay in the building activities frequently takes place as a result of the time which is necessary to allow concrete walls, floors or ceilings to dry completely. In order to accelerate the drying process, it is known to use gas burners which heat the air in the space to be dried, such as, for example, heat guns. The disadvantage of using such gas burners is that, in such cases, an appreciable amount of water is still released as a result of the combustion of the gas, with the result that the drying process is relatively inefficient.

A device for heating asphalt according to the precharacterizing clause of Claim 1 is disclosed in US-A-5, 114,284. In the latter, a flame carrier is formed by a blanket of ceramic material and a gas/air mixture is introduced into a chamber situated above the blanket and distributed uniformly over it. The gas/air mixture ignites at the lowermost surface of the ceramic blanket, as a result of which radiation heat is delivered to the road surface. The heating space underneath the flame carrier is bounded by the outermost housing of the burner and is at a constant height above the flat surface on which the burner is supported by the wheels. The disadvantage of the known device is that, during heating or drying of uneven surfaces, the distance between the rim projecting underneath the flame carrier and the underlying surface may vary, with the result that a non-uniform heating and/or drying takes place. During heating and/or drying of uneven surfaces, the rim projecting under the flame carrier has to be placed at a relatively large distance from the underlying surface, with the result that a relatively large amount of combustion gases can escape under the rim, thereby reducing the efficiency of the heating.

The object of the present invention is to provide a drying device with which both flat and uneven surfaces, such as walls, floors, ceilings or road surfaces can be heated and/or dried quickly and efficiently without an appreciable amount of water being formed during the heating or drying process at the position of the heated surface, the emission of harmful combustion gases being low.

For this purpose, the device according to the invention is characterized in that the lateral sealing members are flexible, an air flow being fed to the flame carrier during operation by the air feed device which is such that an upward force is exerted on the device by the combustion gases in the heating space.

The flexible lateral sealing members, which are formed, for example, by refractory strips or brushes, form a heating chamber which is situated directly above the surface to be dried and in which relatively high temperatures can be reached. As a result of feeding a sufficient quantity of air to the heating chamber via the air-permeable flame carrier, an air cushion is formed inside the heating space by the combustion gases and the (optional) excess of air which is not consumed by the combustion. As a result, a pressure build-up takes place inside the heating space to an overpressure of a few mbar, the air escaping between the surface to be heated and the flexible lateral sealing members. The air cushion exerts an upward force on the heating device, with the result that, when it passes unevennesses, the device can move up somewhat and drop again after passing the unevenness. As a result, an essentially constant distance is obtained between the burners and the surface to be treated. It is also possible to suspend the heating device according to the invention freely, for example on a vehicle for treating a road surface, in which case the device may be freely suspended on an arm above the road surface, for example, by means of chains.

As a result of the air escaping under the sealing members, the bulk of the moisture around the burner is blown away during the drying of, for example, floors and the surface in front of and at the side edge of the burner will be preheated by the high temperature of the escaping air. Furthermore, the flame carrier generates a large amount of radiation heat, with the result that the material to be heated or dried is heated to a great depth. Because the air fed in reaches a very high temperature inside the flame carrier, the steam present in the air can be discharged over the upper side of the burner, with the result that it does not reach the surface to be heated or dried. As a result, an effective heating and/or drying takes place of the surface situated inside the heating chamber.

The flame carrier covers a relatively large surface area of the drying space, which, for example, may be rectangular or elongated and have a surface area of, for example, 1 m². Preferably, the flame carrier comprises a ceramic foam, such as is obtainable from ECO Ceramics B.V., Nijverheidsplein 1 B, 1704 RB Heerhugowaard, The Netherlands. Such ceramic flame carriers have a very great heating range, being continuously variable, for example, from 100 kW/m² to 2000 kW/m². A very complete combustion also takes place with such burners. Preferably, the flame carrier is provided with a gas feed chamber, one side of which is bounded at least partly, by the flame carrier, a gas feed line and also the air feed device debouching into the gas feed chamber. Gas can be distributed uniformly over the surface of the flame carrier by means of the gas feed chamber. A very good mixing of gas and air fed in takes place in the porous flame carrier. Natural gas, propane, butane or mixtures of hydrogen and methane can be used as fuel for the device according to the invention.

To dry walls and ceilings, the device according to the invention can be moved along a gantry placed against the wall or ceiling, for example using a set of wheels along a guide rail. However, the device according to the invention preferably comprises a mobile frame to which the carrier is pivotably attached for drying floors. A carrier arm of the burner is connected to a transverse arm which is provided with a pressure member for exerting a downward pressure on the burner. As a result, during travel over uneven surfaces, the sealing of the drying chamber remains guaranteed and a constant slit width between the flexible flaps and the underlying surface is guaranteed. The pressure member may be designed as a spring or as a movable counterweight. Preferably, the device is provided with a platform for carrying a gas bottle and two vertical frame parts spaced apart and having a right-angled end with a handle thereon.

The invention is described in greater detail by reference to the accompanying drawing, in which: Figure 1 shows a perspective view of an embodiment of a drying and/or heating device for floors according to the present invention, and

Figure 2 shows a drying and/or heating device for vertical surfaces. The drying device 1 according to the present invention comprises a burner 2 having a flame carrier 3 and flexible sealing flaps 4 attached thereto. A heating or drying space 5 is bounded by the sealing flaps 4 and the flame carrier 3. The dimensions of the flame carrier 3 are, for example, 40 x 50 cm, while the distance of the flame carrier 3 above the floor is approximately 5 cm. The flame height of the flames emerging from the flame carrier is between 5 and 20 mm. A maximum surface temperature of the burner is, for example, 1100°C.

The flame carrier 3 is detachably accommodated in a drawer having supports 3', 3" and can be placed at various heights above the surface to be dried. On the underside of the flame carrier 3, a resistance layer may be applied which is connected to a current source not shown in the figure. With the latter, the resistance layer can be heated to red heat so that, for example, a low-temperature heating is possible.

Situated above the flame carrier 3 is a gas feed chamber 6 which also serves to attach the burner 2 to the carrier arm 7. A fan 21, which is electrically fed, for example, by means of a cable not shown in the figure, opens into the gas feed chamber 6. A gas line 8 also opens into the gas feed chamber 6. A gas/air mixture is introduced into the gas feed chamber 6 via the gas regulating stopcock 20 and gas line 8, in which gas feed chamber the gas is distributed over the surface of the flame carrier 3. Inside the porous flame carrier 3, a further mixing of the gas/air mixture takes place with the air fed in by the fan 21 up to a ratio which is optimum for complete combustion. As a result of air flow originating from combustion gases of the gas and from the fan 21, of which air flow an adjustable fraction serves not for combustion but for pressure build-up, an air cushion at an overpressure of a few mbar, for example 1 to 2 mbar, is built up inside the drying space 5. The air escapes via the lower rim of the flexible sealing flaps 4, which are formed, for example, from strips or brushes of a heat- resistant material. Because the burner 2 is largely carried by the air cushion its suspension on a frame can be of relatively simple design and a single-sided support on the underlying surface may be sufficient.

During the combustion of natural gas and propane, the following air flows occur (with a burner surface of 10 x 10 cm): ^"

All the volumes mentioned are based on the amounts of the product at an absolute pressure of 1.013 bar and an absolute.temperature of 273.15 K (0°C).

The suspension comprises a carrier arm 7 which is joined to a ball hinge 22 so that the burner 2 can adapt its orientation with respect to the underlying surface if unevennesses occur. The carrier arm 7 is pivotably attached by means of a bracket 9 to the frame 10. Attached to the transverse arm 11 is a movable weight 12 as a result of moving which the pressure of the burner 2 against the underlying surface, and in this way, the slit width and the air flow through the burner, may be varied.

The frame 10 is provided with a platform 13 on which the gas bottle 14 and the fan 21 are placed. The frame 10 is mobile over the underlying surface by means of swivelling wheels 15. The frame 10 comprises two vertical frame parts 16, 17, each having a right-angled end 18, 19 with a handle thereon. Accommodated between the right-angled ends 18, 19 is a control panel with meters for the gas pressure, the temperature in the drying space 5 and, for example, the travelling speed. The burner 2 can be ignited by means of an igniter 23 by operating a knob mounted on the control panel.

With the aid of the drying device according to the present invention, it is possible to dry floors efficiently and quickly, even if there is a layer of water of several centimetres thereon. Compared with the use of heat guns, relatively little gas has to be combusted for an efficient drying, with the result that the amount of steam which is formed during the drying process can remain limited. The device according to the invention also heats steam present in the air in the flame carrier considerably, with the result that no moisture reaches the surface to be dried, which promotes an efficient drying. The device according to the present invention is not only usable indoors, but can also be used to dry surfaces in, for example, road construction, such as the drying of paint strips applied to a road surface, during the asphalting of road surfaces, during the burning off of paint or in gardening, during the bonding of sheets of, for example, water reservoirs both below and above water, and so forth. For this purpose, the mobile frame 10 can be motorized, for example, with a stepping motor. Furthermore, the use of the burner 6 is not limited to the design shown but it can also be used in conjunction with guide rails for drying horizontal surfaces or for drying ceilings. This is shown diagrammatically in Figure 2, in which the burner 2 is placed against a wall under pressure due to spring elements 23. The burner 2 can be moved vertically along a guide 26 of the frame 10 by means of a shoe 24. During this process, the swivelling wheels 15 may be rotated through 90° and placed in a guide rail 25 situated along the wall.

Claims

1. Device for heating and/or drying surfaces, such as walls, floors or ceilings, comprising a burner (2), a gas feed (8) connected to the burner, lateral sealing members (4) which surround the burner (2) and which, in conjunction with a surface to be dried and/or heated, form the boundary of a heating space (5), the burner (2) comprising an air-permeable flame carrier (3) for distributing a flame over the heating space (5), and also an air feed device (21), connected to the flame carrier, for feeding an air flow to the flame carrier, characterized in that the lateral sealing members (4) are flexible, an air flow being fed to the flame carrier (3) during operation by the air feed device (21) which is such that an upward force is exerted on the device by the combustion gases in the heating space.

2. Device according to Claim 1, characterized in that the flame carrier (3) comprises a ceramic foam.

3. Device according to Claim 1 or 2, characterized in that the flame carrier (3) is provided with a gas feed chamber (6), one side of which is bounded, at least partly, by the flame carrier (3), a gas feed line and also the air feed device opening into the gas feed chamber (6).

4. Device according to one of the preceding claims, characterized in that the flame carrier (3) is provided on its underside with a resistance layer and also with a power supply for heating the resistance layer to red heat.

5. Device according to one of the preceding claims, characterized in that the burner (2) is provided with mounting members which are situated at various distances from the surface to be dried and/or to be heated and to which the flame carrier can be detachably joined.

6. Device according to Claim 1, 2 or 3, characterized in that the device is provided with an ignition mechanism (23).

7. Device according to one of the preceding claims, characterized in that the burner (2) is attached by means of a carrier arm (7) to a mobile frame (10), the carrier arm (7) being joined to a transverse arm (11) provided with a pressure member (12) for exerting a downward pressure on the burner (2).

8. Device according to Claim 7, characterized in that the pressure member (12) comprises a weight which can be moved along the transverse arm.

9. Device according to one of the preceding claims, characterized in that the device is provided with a platform (13) for carrying a gas bottle (14) and with two vertical frame parts (16, 17) spaced apart and having a right-angled end (18, 19) with a handle thereon.