Abstract: A system for pumping a fluid having a viscosity at least five times water's viscosity through at least one heat exchanger. The system includes a positive displacement pump, pumping the fluid through the heat exchanger. The system includes a booster pump that is installed downstream of the heat exchanger. A method for pumping high-viscous fluid through a heat exchanger. The method includes the steps of pumping the high-viscous fluid with a variable speed positive displacement pump. There is the step of driving the fluid through a heat exchanger. There is the step of forwarding the fluid through a booster pump.

Abstract: The present invention pertains to a system for thermal disinfection of sludge with the aim of pathogen reduction. Such thermal sludge treatment systems require a certain minimum detention time t dependent on the temperature T of the heated sludge. The system according to the present invention is a continuous flow system. The system includes means for continuous sludge heating. The heated sludge flows continuously through at least one chamber, whereby the flow through the chamber has a substantially vertical direction. The mean residence time t2 of the sludge between entering the chamber and leaving the chamber is minimum 2 times the time period t required by regulations for conventional batch systems. The ratio of the flow path length of the flow through the chamber or chambers to the hydraulic diameter of the vertical flow through the chamber or chambers l/d is at least 3:1. The higher the ratio t2/t, the smaller can be the required ratio l/d. The relationship is: l/d*t2/t>8.

Abstract: Arrangement and method for the prevention of water entering a pneumatic controller of a vacuum sewer system through a breather line. The proposed pneumatic controller is a non-bleeding controller preventing continuous flow of air from the breather line through the controller. The volume of breather air entering the controller during an evacuation cycle is smaller than the volume of a water trap provided in the breather line. The water trap removes water from the breather air before it enters the controller.

Abstract: The present invention concerns a vacuum sewerage system for collecting wastewater from a number of buildings comprising a vacuum sewer which is on one end connectable to a vacuum source and into which wastewater from the buildings can be aspirated via interphase valves. The vacuum sewer has a height profile comprising a sequence of low and high points, whereby wastewater can accumulate at the low points while the system is at rest. If air flows, the wastewater accumulations are pushed from the low points over the subsequent high points. The invention proposes to provide first and a second sections of the vacuum sewer with different height profiles. The height profiles are such that the maximum volume of the wastewater accumulations at the low points of height profile I is by preferably at least 3 times smaller than the maximum volume of the wastewater accumulations in height profile II.

Abstract: In order to obtain a more intense and quicker sewage purification and a better retaining of the activated sludge flocks in an activated sludge system with aeration tank and subsequently arranged secondary settler, the aeration tank is constructed as a sealed pressure reservoir (10) to which oxygenous gas can be supplied under pressure for dissolution in water, where the secondary settler is a flotation basin (24) and the pressure from the pressure reservoir (10) is available for flotation.