Dark smoke

The Dark Smoke (Permitted Periods) Regulations, give details on circumstances and time limits when dark smoke is allowed. 

Section 2 of this Act prohibits dark smoke from any industrial or trade premises (there is no requirement under Section 2 for the dark smoke to be emitted from a chimney). 

SI 1969/1263 Clean Air (Emissions of Dark Smoke) (Exemption) Regulations... 

Sets out ancillary controls related to air pollution control including regulation of smoke, grit, dust and fume emissions from non-prescnbed mdustnal processes provision of a lower level of control over some smaller combustion plants not covered by IPC or LAAPC prohibition of the emission of dark smoke from any chimney or industrial premises. 

These Acts control smoke from chimneys and open sites. Smoke is not defined but includes soot, ash, etc. The emission of dark smoke (as dark or darker than shade 2 on the Ringleman chart) from chimneys and open sites is made an offence (exceptions are provided for short periods of time). 

New furnaces have to be constructed (as far as is practicable) so as to operate smokelessly. Chimney heights are controlled (see below). Smoke Control Orders can be introduced (to control domestic smoke) and grants are available to convert fireplaces to burn authorized fuels. Smoke (other than dark smoke, which is already controlled) is dealt with by Section 16 of the 1956 Act and is, for the purposes of Part 111 of the 1936 Public Health Act, to be considered as a statutory nuisance. 

Railway engines are dealt with in the same way as premises for the purposes of Section 1 of this Act (which controls dark smoke) except that the owner of the engine is to be held responsible. Other Sections of the Act do not apply. 

Section 1 of the Act prohibits dark smoke from trade premises (the 1956 Act only controlled smoke from chimneys). Bonfires are thus now included. Section 2 controls the rate of grit and dust emission from furnaces and the Minister may make Regulations. These are known as the Clean Air (Emission of Grit and Dust from Furnaces) Regulations 1971 and the Clean Air (Emission of Grit and Dust from Furnaces) (Scotland) Regulations 1971. 

Hamilton RS, Mansfield TA (1990) Airborne particulate elemental carbon its sources, transport and contribution to dark smoke and soiling. Atmos Environ 25 715-723... 

Chronic, 5 am. They waited patiently by the two big bouncers though there was no queue then once inside forgot the midnight argument that had robbed them of Mr Hyde. They left all the ordinary pain of living on the threshold and went down the stairs into a dark smoke-filled room. 

Uses For incendiary purposes in bombs and shells and for dark smoke screens by spraying it with an insufficient amount of air below the stacks of destroyers. 

London smog was an object of fascination. A recent study explains artistic depictions of the murk—by painter Claude Monet and a multitude of writers—through the chemistry of coal tar, the source of the dye chemicals that were so important to the early study of environmental cancer. The yellow morning fog, Oscar Wilde s ochre-coloured hay, was tinted by tars in the smoke of household coal furnaces that burned at low temperature. By afternoon, the dark smoke from hotter-burning industrial furnaces would turn the smog to brown or black.3... 

An unpaid commission, appointed the previous year, sprang to life and proposed ordinances for control of factory emissions. The rules were simple only the visible opacity of smoke was limited. This was just a rough stab at a solution. Organic chemicals were already known to be at the core of the problem, but beyond the constraints imposed indirectly by the restriction on dark smoke, their emissions would not be limited. Still worse, the structure of California government made it hard to put even this straightforward scheme in place. Separate enactments were required from each of Los Angeles County s many cities and, for unincorporated areas, the county itself. 

Several evidents existed for the environmental pollution transferthousands of klllometers and were carried by the wind. Such pollutants have reached the Far East countries as was proven by the colered precipitation of grey snow in the Himalaya area. This action was attributed to the dark (smoke) clouds from the Kuwaiti burning oil fileds in 1991. 

Most of the volatile matter in the coal distilled shortly after firing and either burned in the pre-heating zone, or was emitted to atmosphere as dark smoke. 

Operation with a limited excess of air results in the emission of some volatiles as dark smoke. This, coupled with the relatively low reactivity of the lime has caused many oil-fired shaft kilns to be replaced by modern designs. 

Anthracite (see Table 14.3) typically contains 4 to 10% of volatile matter, which results in higher heat usages than coke and in the emission of dark smoke. It needs to be strong of the correct particle size and have a high ash fusion temperature. 

The fuels used in the various designs of modern shaft kilns currently available (see section 16.8) are selected to produce medium to light-burned lime, at high thermal efficiencies, without the emission of dark smoke. All designs can use natural gas, most can also use fuel oil and some can operate on pulverised solid fuel. 

Frequently, oil firing also resulted in dark smoke emission, owing to the need mentioned above to restrict the levels of excess air to ensure an acceptable lime reactivity. 

The Clean Air Act applies to all small and medium-sized companies operating furnaces, boilers or incinerators. Compliance with the Act does not require an application for authorization and so companies must make sure that they do not commit an offence. In general the emission of dark smoke from any chimney is unacceptable. The emission of dark smoke from any industrial premises is also unacceptable. This might be caused by, for example, the burning of old tyres or old cable. 

In England, Scotland and Wales it is not necessary for the Local Authority to have witnessed the emission of dark smoke before taking legal action. Simply the evidence of burned materials, which potentially give rise to dark smoke when burned, is sufficient. In this way the law aims to stop people creating dark smoke under the cover of darkness. 

It would appear that the molybdenum acts as a kind of catalyst to convert PVC degradation species from becoming aromatic compounds (these bum to produce the familiar dense, dark smoke), into more linear aliphatic species or carbonaceous char. 

The key requirement for PVC when it is eventually made to bum is the minimisation of the dark smoke levels emitted. Antimony, zinc and molybdenum compounds were incorporated as well as hydrated aluminium and magnesium fillers. The fire testing covered Limiting Oxygen Index, heat release parameters and smoke emission. General heat stability (integrity) and mechanical impact tests were also performed. 

Most commercial plastics are readily combustible, and some evolve dark smoke on binning. This smoke is indirectly responsible for most fire fatalities. The cost of fire damage to buildings and contents has been estimated at up to 30 billion euros/year in Europe. 

Ringed Roof. A furnace roof consisting of arches of bricks unbonded with adjacent arches (cf. bonded roof). Ringelmann Chart. A chart divided into five (Nos. 0-4) shades of darkness introduced in the late 19th century by Professor Ringelmann, of Paris, as a means of designating the blackness of smoke emitted from industrial chimneys. The charts have been standardized (B.S. 2742) and are used in the ceramic industry in compliance with the Clean Air Act in which dark smoke is defined as equal to, or denser than, Shade 2 on the Ringelmann Chart. 

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