Steel plant with direct cooling water treatment circuit and related process
AssigneeDanieli & C. Officine Meccaniche SpA
InventorsAntonio NARDELLA, Massimo FABIANI
Life of this patent
Estimating the term…
Abstract
The invention concerns a steel plant for the production of long or flat products with a treatment circuit of water deriving from direct cooling and a relative process that envisage that the cooling waters coming from first machinery that produce cooling waters less loaded with scale (with a low content of suspended solids), as quenching units, directly feed second machinery producing cooling waters rich in scale, such as rolling mills, preferably by first passing through at least one collecting tank to then be treated in a succession of water treatment devices such as scale pits, clarifiers, filters and cooling towers to feed the first machinery again.
Claims10
A steel plant for the production of long products, in particular bars, rods, profiles, wires and the like, or for flat products, in particular strips, sheets and the like comprising:
- (a) a plurality of machinery equipped with direct cooling systems and divided into at least a first and a second group of machinery, each group comprising one or more pieces of machinery, wherein the groups of machinery are distinguished by the different higher or lower concentration of scale released into the cooling water accumulated during the use of each group of machinery;
- (b) a circuit (C, C″, C4) of treatment of direct cooling waters exiting said direct cooling systems, comprising a plurality of cooling water treatment devices, wherein
- (i) said direct cooling systems of said two groups of machinery are connected in series, wherein said direct cooling systems of said second group of machinery producing cooling waters with a higher scale concentration are situated downstream of said direct cooling systems of said first group of machinery producing cooling waters with a lower concentration of scale, so that said direct cooling systems of said first group of machinery feed said direct cooling systems of said second group of machinery;
- and in that
- (ii) said direct cooling water treatment circuit (C, C″, C4) is arranged downstream of said second group of machinery.
A process for treating direct cooling waters of a steel plant for the production of long products, in particular bars, rods, profiles, wires and the like, or for flat products, in particular strips, sheets and the like, comprising the following steps:
- (I) performing direct cooling in the steel plant resulting in the production of cooling waters rich in scale content and cooling waters less loaded with scale, depending on the machinery which make up said steel plant, which are divided into at least two groups of machinery, depending on the scale content released from the product processed by said groups of machinery into the cooling water;
- (II) conveying the heated cooling water with a lower scale content exiting the respective first group of machinery to the second group of machinery of the plant which produce waters rich in scale, preferably by intermediate storage in a collecting tank;
- (III) purification of the cooling waters heated and contaminated by the second group of machinery in a succession of water treatment devices comprising in the following order at least one tank, preferably at least two scale and/or oil separation tanks, at least one filtration unit and at least one cooling tower, wherein preferably under wet bulb conditions <26° C., the water is cooled to or below 30° C.;
- (IV) reintroduction, at least partially, of the waters cleaned and cooled during step (III) into the direct cooling systems of said first group of machinery and/or into said collection tank, if any.
Dependencies are inferred from the claim text.