View report page

2
many failures of appliances of a more pretentious character, such as the "Beehive" at Richmond, and
others, which need not be further referred to.
There are, however, four types of destructors in general use, which we think should be fully
described, each of which is more or less successful when properly used in effecting the desired purpose.
We propose to describe Fryer's destructor first, because this one is more widely used than the
others, although it is not in our opinion a perfect appliance.
The subjoined drawing shews the details of Fryer's destructor, an example of which has been
erected at the Barking outfall works by. the Main Drainage Committee, for the purpose of burning the
solid matters taken out of the sewage by means of screens. It has been found well adapted for this
purpose.
Fryer's destructor usually consists of a group of cells, each internally about 9 ft. long, and 5 ft.
wide, covered by a segmental fire-brick arch, 3 ft. 6 in. high. The furnace bars are inclined with the
slope towards the front, the usual fall being about 1 in 3, and the bottom is usually of fire-brick, forming
a dead plate at the back for a distance of about 4 ft., when fire-bars take the place of the hearth for the
remainder of the furnace. The material to be dealt with is fed into the furnace by means of a hopper
and is from time to time raked down to the fire bars where combustion takes place. A sloping roadway
leading from the ground level to the top of the furnaces forms a part of the construction in this
and other types of destructors. The furnace is effective in reducing about 8 tons of refuse per cell per
24 hours to dust and clinker, which latter is often a useful and saleable product. There is one feature
in connexion with this form of furnace, however, which militates against its use from the nuisance
point of view, and it is this, that the outlets for the products of combustion are at the back, and that
whilst a charge is burning upon the furnace bars the next charge lies upon the dead hearth at the
back near the outlet flue, where it undergoes drying and partial decomposition, with the result that offensive
vapours are given off, and these pass into the flue without being exposed to sufficient heat to render
them inoffensive, and in some cases have produced a nuisance. A second furnace called a "cremator"
has therefore in many cases been placed in the flue leading to the chimney shaft for the purpose of
resolving the organic matters present in the vapour; but the greatly increased cost consequent upon
the introduction of the cremator has led to its disuse altogether in some cases. We were informed at
Hornsey, for instance, that the cremator was not used because the cost of burning the refuse was
increased by nearly 50 per cent., which statement, so far as increased cost is concerned, was confirmed
by our inquiries at Bradford.
The next type of destructor to be described is Warner's as used at Hornsey and elsewhere. The
furnace is very like Fryer's, but the details have been improved as regards the means of charging, and
controlling the vapour given off. We observed at some places that when the furnace doors were thrown
open for the purpose of withdrawing the clinker, a fierce draught through the furnace was produced
which carried fine ashes and charred paper through the flues and up the chimney, from which latter
they escaped in sufficient quantities to be easily recognised. At Hornsey, in the Warner destructor,
the dampers in the furnace flues are closed before the furnace doors are opened for the purpose of
clinkering, and the evils referred to are remedied. As a further precaution against the escape of dust,
baffle walls and dust pits have been constructed in the main flue, and we were informed that complaints
with regard to this destructor had not been received, although houses letting at about £80 a year are
within a quarter of a mile of its site. We cannot, however, regard this form of furnace as being
altogether free from the evils pointed out as affecting Fryer's destructor, because the outlets for the
products of combustion are at the back of the furnace, in close proximity to the inlet for the refuse to
be burnt.
The furnace in use at Manchester, designed by Mr. Whiley, the superintendent of the cleansing
department of the Manchester Corporation, is of ingenious construction, and with such improvements
as may be found advisable or desirable jn practice, seems likely to prove an excellent appliance. On
referring to the drawing, it will be observed that the material to be burnt is introduced into the furnace
by means of a shoot; it falls upon fire-bars to which a rocking motion is imparted, and it is slowly
carried forward for the whole length of the furnace, the combustible matters being destroyed as the
material traverses the furnace, whilst the clinker drops through the door provided for the purpose at
the front end of the destructor. The outlet for the products of combustion appears to be rather too
near the shoot for the crude material, but as forced draught is employed by means of a Root's blower,
the heat in the furnace is so intense that the arch of the furnace glows, and it is perhaps possible
that the vapours given off by the partially burnt refuse are decomposed in passing through the furnace
flues. The fact that the Manchester Corporation are now providing a very large installation of this
form of destructor, after having given it an extended trial, must be regarded as evidence of the value
of this appliance. If, upon further experience, the machine—for so it may be designated—proves
successful, it will no doubt be largely adopted by reason of its automatic action, which reduces manual
labour to the minimum.
The next type to be noted is the "Horsfall," as in use at Oldham. A section of this form of
destructor is given herewith, and it will be observed that whilst the general features of Fryer's
destructor are retained, the details differ very widely, and more particularly with regard to the outlets
for the products of combustion. These are placed at the opposite end to that at which the material to
be burnt is introduced, and consequently have to pass over the hottest part of the furnace; moreover,
a steam blast is used in connection with a closed ashpit, and as a result the temperature of the furnace
is so high that at Oldham the lining was observed to be glowing, and there can be no doubt but that in
furnaces of this type, the decomposition of the organic and combustible matters is so perfect that no
nuisance is likely to arise from its use.
At Leeds, the then Borough Engineer, erected a set of Fryer's destructors in 1876, but
more recently Mr. Hewson, the present Borough Engineer, has constructed another sot from
his own designs, a section of which is given herewith. It will be observed that the general
features of both the Fryer and Horsfall furnace have been retained, but there is a great