SINGEING OF WEBS. The old furnace for singeing cotton goods is represented in longitudinal section, [fig. 1030.], and in a transverse one in [fig. 1031.] a is the fire-door; b, the grate; c, the ash-pit; d, a flue, 6 inches broad, and 21⁄2 high, over which a hollow semi-cylindrical mass of cast iron e, is laid, one inch thick at the sides, and 21⁄2 thick at the top curvature. The flame passes along the fire-flue d, into a side opening f, in the chimney. The goods are swept swiftly over this ignited piece of iron, with considerable friction, by means of a wooden roller, and a swing frame for raising them at any moment out of contact.
In some shops, semi-cylinders of copper, three quarters of an inch thick, have been substituted for those of iron, in singeing goods prior to bleaching them. The former last three months, and do 1500 pieces with one ton of coal; while the latter, which are an inch and a half thick, wear out in a week, and do no more than from 500 to 600 pieces with the same weight of fuel.
In the early part of the year 1818, Mr. Samuel Hall enrolled the specification of a patent for removing the downy fibres of the cotton thread from the interstices of bobbin-net lace, or muslins, which he effected by singeing the lace with the flame of a gas-burner. The second patent granted to Mr. Hall, in April, 1823, is for an improvement in the above process; viz., causing a strong current of air to draw the flame of the gas through the interstices of the lace, as it passes over the burner, by means of an aperture in a tube placed immediately above the row of gas-jets, which tube communicates with an air-pump or exhauster.
[Fig. 1032.] shows the construction of the apparatus complete, and manner in which it operates; a, a, is a gas-pipe, supplied by an ordinary gasometer; from this pipe, several small ones extend upwards to the long burner b, b. This burner is a horizontal tube, perforated with many small holes on the upper side, through which, as jets, the gas passes; and when it is ignited, the bobbin-net lace, or other material intended to be singed, is extended and drawn rapidly over the flame, by means of rollers, which are not shown in the figure.
The simple burning of the gas, even with a draught chimney, as in the former specification, is found not to be at all times efficacious; the patentee, therefore, now introduces a hollow tube c, c, with a slit or opening, immediately over the row of burners; and this tube, by means of the pipes d, d, d, communicates with the pipe e, e, e, which leads to the exhausting apparatus.
This exhausting apparatus consists of two tanks, f and g, nearly filled with water, and two inverted boxes or vessels, h and i, which are suspended by rods to the vibrating beam k; each of the boxes is furnished with a valve opening upwards; l, l, are pipes extending from the horizontal part of the pipe e, up into the boxes or vessels h and i, which pipes have valves at their tops, also opening upward. When the vessel h descends, the water in the tank forces out the air contained within the vessel at the valve m; but when that vessel rises again, the valve m being closed, the air is drawn from the pipe e, through the pipe l. The same takes place in the vessel i, from which the air in its descent is expelled through the valve n, and, in its ascent, draws the air through the pipe l, from the pipe e. By these means, a partial exhaustion is effected in the pipe e, e, and the tube c, c; to supply which, the air rushes with considerable force through the long opening of the tube c, c, and carries with it the flame of the gas-burners. The bobbin-net lace, or other goods, being now drawn over the flame between the burner b, b, and the exhausted tube c, c, by means of rollers, as above said, the flame of the gas is forced through the interstices of the fabric, and all the fine filaments and loose fibres of the thread are burnt off, without damaging the substance of the goods.