Abstract: The gas-cleaning apparatus for a blast furnace operating under pressure using a differential-pressure washing arrangement whereby the differential-pressure washer comprises at least one annular gap with an annular-gap passage and an axially adjustable body received in the annular gap washer. The nozzle is disposed upstream of the annular-gap washer to spray the washing liquid into the gas which is accelerated through the annular gap. The position of this body is controlled in response to the gas pressure within the head of the blast furnace. The annular gap of the washer diverges in the direction of flow of the gas and the body has a complementary shape so that the gap width remains generally constant although its flow cross section increases with the diameter of the annular gap in the direction of flow of the gas.

Abstract: Waste gas from a coal-fired power plant is scrubbed with a lime-water mixture to form a sludge whose water content is reduced and which is mixed with a binder such as water glass. This mixture is then pelletized to produce hard water-stable material suitable for use as an aggregate or filler. The waste gas may be stripped of its fly ash and this ash added to the sludge to thicken it.