Method and circuit arrangement for recovering heat from wastewaters

Abstract

The invention relates to a method and circuit arrangement for recovering heat from wastewaters, comprising—a wastewater circuit having a sewage intake shaft (4) connected to a common sewer (1) through a raw sewage line (2), and at least one heat exchanger (7) connected to the sewage intake shaft (4,—a primary circuit having at least one heat pump (8), and—a secondary circuit comprising at least one storage tank (9) and at least one heat utiliser, where the wastewater circuit, the primary circuit, and the secondary circuit are arranged to be in heat-transfer connection, and,—where the sewage is fed to one side of the wastewater circuit heat exchanger (2) and the working medium of the heat pump (9) of the primary circuit is fed to the other side of the same heat exchanger (9), with the working medium of the heat pump (8) being fed in a storage tank (9) and the storage tank (9) is connected to a heat utiliser. The invention is essentially characterised by that the wastewater circuit is spatially separated from the primary circuit and the secondary circuit, and that a screening case (5) is arranged in the sewage intake shaft (4) of the wastewater circuit, where a raw sewage line (2) connecting the common sewer (1) with the sewage intake shaft (4) is terminated in the screening case (5), and where one end of a coarse material remover (6) extends into the screening case (5), with the other end of the coarse material remover (6) being connected to a utilised sewage return line (3) that connects the sewage intake shaft (4) and the common sewer (1), and also that screened sewage is fed from the sewage intake shaft (4) to one side of the heat exchanger (7), with utilised sewage leaving the heat exchanger (7) being fed in the utilised sewage return line (3) such that it washes the coarse material removed by the coarse material remover (6) back to the utilised sewage return line (3).

Dependencies are inferred from the claim text.