View report page

36
Smoke Measuring Station.
The smoke measuring station installed in the Department in 1956
continues to give valuable information concerning smoke density and
sulphur dioxide in the atmosphere. The readings are taken by
members of the staff of the Department, and the Department of
Scientific and Industrial Research receive the results and collate the
information with other results obtained from Authorities all over the
Country.
Notification of Installation of Furnaces.
Notification is required under Section 3 of the Clean Air Act, 1956,
of the installation of any furnace with a heating capacity of 55,000
B.T.U's or more per hour. The Section does not generally apply to
furnaces designed solely or mainly for use for domestic purposes. The
purpose of the Section is to see that any new furnaces installed shall
be, so far as is practicable, capable of being operated without emitting
smoke. Seven such notifications were received during the year.
Chimney Heights.
A Circular was received from the Minister of Housing and Local
Government, referring to the duty of the local authority to satisfy themselves
that new chimneys, to which Section 10 of the Clean Air Act
applies, should be high enough to prevent, as far as practicable, smoke,
grit, dust and gases emitted from the chimney becoming prejudicial to
health or a nuisance. A Memorandum was enclosed to assist in the
calculation of chimney heights, based on the amount of flue gases the
chimney would be expected to emit as a function of the maximum rate
of emission of sulphur dioxide. The Memorandum was not applicable
to all chimneys and applied only to: —
(a) chimneys of industrial boiler plant of a maximum continuous
rating greater than approximately 650 lb. steam/hr. and not
exceeding 450,000 lb. steam/hr.
or
(b) to chimneys serving furnaces burning fuel at a maximum rate
greater than approximately 100 lb./hr. of coal or 50 lb./hr. of
oil, and not exceeding 50,000 lb./hr. of coal or 30,000 lb./hr.
of oil.
The method was to be regarded as a guide rather than a mathematically
precise way of reaching a final decision on chimney height,
and modified in the light of particular local circumstances.
The question of chimney height is considered in the light of the
Minister's Memorandum when notification of the installation of a boiler
is made under Section 3 of the Act.
Exemption of Premises engaged in Investigation and Research.
Section 21 of the Clean Air Act, 1956, provides for firms engaged
in research with regard to air pollution and the efficiency of furnaces
generally to apply for exemption in the event of emission of smoke
above the prescribed density.
One application for exemption under this Section was received,
and this was granted for one year. No untoward emissions were
observed.