GB1601704A - Heating bed for an industrial ironing machine - Google Patents

Description

(54) HEATING BED FOR AN INDUSTRIAL IRONING MACHINE (71) We, ALDERCLASS HOLDINGS LIMITED, a British Company, of 65 Renfield Street, Glasgow, Great Britain, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to industrial processing machines having a heating bed with fluid ducts for circulating fluid to distribute heat through the bed from a heat generator.

The invention is concerned particularly with such heating beds in industrial ironing machines.

For many years, industrial ironing machines have been designed for heating by steam.

Usually, channels, voids or ducts in the hot bed of the ironing machine are designed in accordance with established requirements of a steam heating system which requirements include inter alia duct sizes adequate to accommodate condensate without impairing the accessibility of heat transferring surfaces to steam.

More recently, it has been proposed to design industrial ironing machines for heating by a circulating fluid which at all times remains in a liquid state. Ironing machines operate at temperatures above the boiling point of water at normal temperature and pressure, and, therefore, an oil or pressurised water has been used as the circulating fluid although water requires to be highly pressurised to maintain its liquid state. In such proposed ironing machines, the hot bed ducts are of different configuration to those of a steam system.

It has hitherto been found, particularly in connection with industrial ironing machines, that where a machine incorporates a heating system designed for use with steam, then if, in that machine, oil is used instead of steam, the performance of the machine drops below a minimum acceptable performance for economic or commercial use. The same has been found in the case where the machine is designed primarily for use with oil and steam is used instead of oil. In the former case, the duct cross-sectional area is such that an uneconomic pumping capacity is required for the circulation of oil at a velocity consistent with efficient exchange of heat between oil and the hot bed. In the latter case, the duct or void configurations are such that proper accommodation of condensate is not achieved.

At least for some time, both "steam" and "oil" heating systems will be in demand.

Accordingly, manufacturers, not only of ironing machines, but of many other machines and appliances for industrial or commercial use, are faced with a decision as to the best choice between designing for steam and designing for oil; and this decision can be problematic because there are both advantages and disadvantages in adopting either system.

According to one aspect of the present invention, we provide an industrial processing machine having a heating bed with fluid ducts for circulating fluid to distribute heat through the bed from a heat generator, the ducts being dimensioned and arranged so that the performance of the machine is commercially useful regardless of whether the fluid used is steam or liquid.

In heating systems designed hitherto with ducts for oil (or other liquids), certain flow velocities have been indicated as minimum values consistent with attaining acceptable efficiency of heat transfer from the hot liquids having regard inter alia to the need for turbulence in the liquid flow.

We have found that these minimum values can be reduced without necessarily degrading heat transferring characteristics.

According to another aspect of the present invention, we provide an industrial processing machine having a heating bed with fluid ducts for circulating fluid to distribute heat through the bed from a heat generator, the ducts being dimensioned and arranged so that the performance of the machine is commercially useful regardless of whether the fluid used is steam or liquid, one of the ducts incorporating an auxiliary outlet for condensate whereby when the fluid used is steam obstruction by condensate within said one duct is allieviated by way of said auxiliary outlet.

On the basis of our aforesaid finding that liquid flow velocities can be reduced, the heating bed in accordance with the present invention can be used with oil as the circulating fluid. Also, with the provision of an auxiliary outlet for condensate, the same bed can be used with steam. In each case, the performance of the heating bed is commercially useful.

Industrial ironing machines include an elongate ironing or heating bed of part-cylindrical configuration, this bed being heated, in use, by heat transfer from fluid circulating in ducts at the outer surface of a main curved bed plate or wall.

Further, according to the present invention, we provide a heating bed for an industrial ironing machine being an industrial processing machine as aforesaid.

Still further, according to the present invention, we provide an industrial ironing machine incorporating a bed as aforesaid.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a diagrammatic representation of a cross-section through an industrial ironing machine bed in accordance with the present invention; and Figure 2 is a flow diagram relating to the flow ducts or channels in Figure 1.

In the drawings, the main part-cylindrical steel bed plate of the ironing machine bed is indicated by reference numeral 30. One of several longitudinally spaced support plates is shown at 31. The general configuration and construction of such beds is known. The process or work input side of the bed is indicated by arrow A.

Ducts in the form of straight channels 1 to 20 extend side-by-sidelongitudinally of the bed plate 30, these channels being constituted by appropriate steel sections of part-circular cross-section which are fixed in position by welding (not shown). The steel sections are arranged mutually overlapping as illustrated in Figure 1. Thus, all channels with the exception of channel 10 have their upper longitudinal edges welded to the bed 30 and their lower longitudinal edges welded to the adjacent lower channel along a line thereon spaced from and parallel with its upper edge.

The channels 1 to 20 are provided with inlet/outlet connections, referred to hereinafter in greater detail, arranged to permit four separate and mutually independent fluid flows in four groups of the channels. Thus, No. 1 flow uses channels 1 to 5; No. 2 flow uses channels 6 to 10; No. 3 flow uses channels 11 to 15; and No. 4 flow uses channels 16 to 20.

Mutually adjacent channels are interconnected at one end only, and all of the channels in each group or "flow" are interconnected in series as can be seen by reference to the arrows in Figure 2 inserted to illustrate these connections in No. 1 flow.

The inlet/outlet connections for the four channel groups are indicated by references C1 and C3 to C9. Thus, connections C1 and C3 are positioned at the extremities of No. 1 flow; C4 and C5 of No. 2 flow; C6 and C7 of No. 3 flow; and C8 and C9 of No. 4 flow.

Reference C2 indicates an auxiliary outlet connection in No. 1 flow, hereinafter explained.

The ducts are designed so that the ironing bed can be commercially usefully operated using a heating system in which oil is the circulating fluid; and also using a heating system in which steam is the circulating fluid. To this end, the cross-section of each channel is dimensioned to be consistent with good heat transferring flow characteristics without necessitating the use of higher flow rates which particularly require higher oil pumping capacities. The channels are, however, smaller in respect of cross-sectional area than is usually indicated for "steam" systems. Nevertheless, the channels of Nos. 2, 3 and 4 flows are suitable for steam operation having regard to the duct lengths and thermal gradients at these zones of the ironing bed during processing. No. 1 flow is associated with the greatest thermal gradient during processing and undue obstruction by condensate within No. 1 flow is alleviated by use of the auxiliary condensate outlet connection C2.

In order to achieve satisfactory operation of the auxiliary outlet feature, when steam is used, a steam separator (not shown) is incorporated at the connection C2 to obviate or mitigate by-passing of the auxiliary outlet by condensate. The described overlapping arrangement of the steel sections provides, in the channels, accommodation for condensate away from the heat transfer face of the bed 30. This accommodation is illustrated in Figure 1, by way of example, by the cross-hatched areas in channels 1 to 4.

In use with "steam" and "oil" systems respectively, the designations of the inlet/outlet connections are as follows: Connection Designation for Designation for "Steam" system "Oil" system C1 inlet inlet C2 auxiliary outlet closed (not used) C3 outlet outlet C4 inlet inlet C5 outlet outlet C6 outlet inlet C7 inlet outlet C8 outlet inlet C9 inlet outlet The number and groupings of the channels is determined with reference to the diameter and length of the bed or series of beds. The arrangements described above are appropriate for beds of less than one metre diameter and up to four metres in length. The cross-sectional area of each duct is of the order of 6.5 cms2.

WHAT WE CLAIM IS: 1. An industrial processing machine having a heating bed with fluid ducts for circulating fluid to distribute heat through the bed from a heat generator, the ducts being dimensioned and arranged so that the performance of the machine is commercially useful regardless of whether the fluid used is steam or liquid.

2. An industrial processing machine having a heating bed with fluid ducts for circulating fluid to distribute heat through the bed from a heat generator, the ducts being dimensioned and arranged so that the performance of the machine is commercially useful regardless of whether the fluid used is steam or liquid, one of the ducts incorporating an auxiliary outlet for condensate whereby when the fluid used is steam obstruction by condensate within said one duct is allieviated by way of said auxiliary outlet.

3. An industrial processing machine according to Claim 1 or 2, the machine being an ironing machine.

4. An ironing machine according to Claim 3, wherein the ducts are straight channels which extend side-by-side longitudinally of the heating bed.

5. An ironing machine according to Claim 4, wherein the channels are provided with inlet/outlet connections arranged to permit separate fluid flows respectively in two or more groups of mutually adjacent channels.

6. An ironing machine according to Claim 5 when appended to any one of Claims 2 to 4, wherein said auxiliary outlet for condensate is provided in at least that of said groups occupying a process input position on the bed.

7. An ironing machine according to any one of Claims 4 to 6, wherein the channels are formed by channel sections, at least some of the sections having their longitudinal edges in overlapping relationship with an adjacent lower section thereby to provide in the relevant channels accommodation for condensate away from the heat transfer surface of the bed.

8. An ironing machine according to Claim 5 or 6, or Claim 7 when dependent on Claim 5 or 6, wherein there are twenty channels, and inlet/outlet connections are arranged to permit four separate fluid flows respectively in four groups of mutually adjacent channels.

9. An ironing machine according to any one of Claims 3 to 8 when appended to Claim 2, including a steam separator at the auxiliary outlet for condensate.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (11)

**WARNING** start of CLMS field may overlap end of DESC **. In use with "steam" and "oil" systems respectively, the designations of the inlet/outlet connections are as follows: Connection Designation for Designation for "Steam" system "Oil" system C1 inlet inlet C2 auxiliary outlet closed (not used) C3 outlet outlet C4 inlet inlet C5 outlet outlet C6 outlet inlet C7 inlet outlet C8 outlet inlet C9 inlet outlet The number and groupings of the channels is determined with reference to the diameter and length of the bed or series of beds. The arrangements described above are appropriate for beds of less than one metre diameter and up to four metres in length. The cross-sectional area of each duct is of the order of 6.5 cms2. WHAT WE CLAIM IS:

1. An industrial processing machine having a heating bed with fluid ducts for circulating fluid to distribute heat through the bed from a heat generator, the ducts being dimensioned and arranged so that the performance of the machine is commercially useful regardless of whether the fluid used is steam or liquid.

2. An industrial processing machine having a heating bed with fluid ducts for circulating fluid to distribute heat through the bed from a heat generator, the ducts being dimensioned and arranged so that the performance of the machine is commercially useful regardless of whether the fluid used is steam or liquid, one of the ducts incorporating an auxiliary outlet for condensate whereby when the fluid used is steam obstruction by condensate within said one duct is allieviated by way of said auxiliary outlet.

3. An industrial processing machine according to Claim 1 or 2, the machine being an ironing machine.

4. An ironing machine according to Claim 3, wherein the ducts are straight channels which extend side-by-side longitudinally of the heating bed.

5. An ironing machine according to Claim 4, wherein the channels are provided with inlet/outlet connections arranged to permit separate fluid flows respectively in two or more groups of mutually adjacent channels.

6. An ironing machine according to Claim 5 when appended to any one of Claims 2 to 4, wherein said auxiliary outlet for condensate is provided in at least that of said groups occupying a process input position on the bed.

7. An ironing machine according to any one of Claims 4 to 6, wherein the channels are formed by channel sections, at least some of the sections having their longitudinal edges in overlapping relationship with an adjacent lower section thereby to provide in the relevant channels accommodation for condensate away from the heat transfer surface of the bed.

8. An ironing machine according to Claim 5 or 6, or Claim 7 when dependent on Claim 5 or 6, wherein there are twenty channels, and inlet/outlet connections are arranged to permit four separate fluid flows respectively in four groups of mutually adjacent channels.

9. An ironing machine according to any one of Claims 3 to 8 when appended to Claim 2, including a steam separator at the auxiliary outlet for condensate.

10. A heating bed for an industrial ironing machine, substantially as hereinbefore

described with reference to and as shown in the accompanying drawings.

11. An industrial ironing machine incorporating a heating bed as claimed in Claim 10.