The invention relates to a multistage membrane distillation device comprising a heating stage (28), preferably multiple condensing/evaporating stages (12), and a condensing stage (36) through which a liquid to be concentrated is passed in succession. Each condensing/evaporating stage comprises at least one condensing unit (K) and at least one evaporating unit (V). Each condensing unit comprises a first steam chamber that is delimited at least partly by a condensation wall (16), and each evaporating unit comprises a second steam chamber that is delimited at least partly by a steam-permeable liquid-tight membrane wall (20). At least one flow channel which is formed between such a condensing unit K and such an evaporating unit V that adjoins said condensing unit and which conducts the liquid to be concentrated is provided in each condensing/evaporating stage so that the liquid to be concentrated is heated by means of the condensation wall, and the steam that is generated from the liquid to be concentrated reaches the second steam chamber through the membrane wall. The steam that is produced in a respective preceding stage is conducted into a condensing unit of the immediately following stage via a steam channel which exclusively conducts said steam and which exclusively further conducts said steam to the immediately following stage.

The present invention relates to a method for contemporaneously recovering ammonia and carbon dioxide from an aqueous solution thereof, possibly comprising their condensates, in a synthesis process of urea, characterized in that it comprises a hydrophobic microporous membrane distillation phase of an aqueous solution comprising ammonia, carbon dioxide and their saline compounds or condensates, said distillation being carried out at a temperature ranging from 50 to 250 C. and a pressure ranging from 50 KPa to 20 MPa absolute, with the formation of a residual aqueous solution, possibly comprising urea, and a gaseous permeate stream, comprising ammonia, carbon dioxide and water. The present invention also relates to an apparatus for effecting the above method and a production process of urea which comprises the above method.

The technology disclosed relates to an arrangement for membrane distillation made of at least one plate including a structure having at least one depression or cavity. A membrane is an integral/integrated part of the plate structure or is joined to surface portions of a first side of the structure of the at least one plate so that the joined membrane is substantially parallel with and is facing a relatively thin wall constituting at least some of the more central portions of the plate structure. The surface portions of the membrane are directly joined to the surface portions of the plate structure to form a compartment configured for condensing gas into liquid. Two plates may be directly joined to each other to form a compartment for a warm-liquid channel and/or two plates may be joined to each other to form a compartment for a cooling channel.

Provided is a temperature-based dialysate regeneration device for regulating a temperature of dialysate discharged from a hemodialyzer to remove uremic toxins and waste therefrom, the temperature-based dialysate regeneration device including: a Joule-Thomson refrigerator, including a compressor, condenser, expander and evaporator, an adsorbent column, and a dialysate heat exchanger in which heat transfer occurs between dialysates. The refrigerant used for the JT refrigerator may be a mixture of two or more refrigerants to enhance the heat transfer generated by the latent heat in the evaporator and the condenser.

A hollow fiber membrane bundle configured to be used in an artificial lung and comprised of integrated hollow fiber membranes 31 has hollow portions through which a fluid passes. The hollow fiber membrane bundle is shaped as a cylinder body. In addition, the hollow fiber membrane 31 is tilted with respect to a central axis O of the cylinder body, is wound around the central axis O of the cylinder body, and satisfies the following conditions. An inner diameter d.sub.1 of the hollow fiber membrane 31 is equal to or smaller than 150 m, a tilt angle with respect to the central axis O of the cylinder body of the hollow fiber membrane 31 is equal to or smaller than 60, and a ratio D.sub.1/L of an outer diameter D.sub.1 of the cylinder body to a length L of the cylinder body is equal to or greater than 0.4.

In a fuel supply device for separating raw fuel into high-octane fuel and low-octane fuel and supplying the fuel, to arrange the structural components compactly and to facilitate sealing against fuel vapor, the fuel supply device (1) includes: a raw fuel tank (2) for storing raw fuel; a separator (6) provided inside the raw fuel tank to separate the raw fuel into high-octane fuel that contains a greater amount of components with high octane numbers than the raw fuel and low-octane fuel that contains a greater amount of components with low octane numbers than the raw fuel; and a high-octane fuel tank (5) provided inside the raw fuel tank to store the high-octane fuel separated from the raw fuel by the separator.

A one-way valve includes a housing with a center axis. The housing includes a peripheral side wall around the center axis, and an inward flange protruding from the peripheral side wall toward the center axis. A valve member is inserted into the housing and includes an outer peripheral surface around the center axis, and an outward flange protruding from the outer peripheral surface toward the peripheral side wall. A coil spring includes a first axial end having a first diameter and being in contact with the inward flange and the peripheral side wall, a second axial end having a second diameter smaller than a first diameter, the second axial end being in contact with the outward flange and the outer peripheral surface, and a body portion provided between the first axial end and the second axial end and having diameters decreasing from the first diameter to the second diameter.

A water purification system utilizes an ionomer membrane and mild vacuum to draw water from source water through the membrane. A water source may be salt water or a contaminated water source. The water drawn through the membrane passes across the condenser chamber to a condenser surface where it is condensed into purified water. The condenser surface may be metal or any other suitable surface and may be flat or pleated. In addition, the condenser surface may be maintained at a lower temperature than the water on the water source side of the membrane. The ionomer membrane may be configured in a cartridge, a pleated or flat plate configuration. A latent heat loop may be configured to carry the latent heat of vaporization from the condenser back to the water source side of the ionomer membrane. The source water may be heated by a solar water heater.

A desalination system (1) for producing a distillate from a feed liquid includes: a steam raising device (2) having a liquid section (5) and a steam section (6) which are separated by a membrane system (7); a membrane distillation device (3) having a first steam section (11) and a liquid section (12) which are separated by a wall (14) and having a second steam section (13) which is separated from the liquid section (12) by a membrane system (15); and a heat exchange device (4) having a first liquid section (21) and a second liquid section (22), which are separated by a wall (23).

The invention relates to an apparatus (10) for drying and/or cooling gas (12), in particular air, by means of a hygroscopic solution (14), said apparatus comprising an absorption device (16) which comprises at least one gas flow duct (18) and at least one flow duct (20) carrying the hygroscopic solution, wherein the inner or gas chamber (22) of a respective gas flow duct is at least partly delimited by a vapor-permeable liquid-tight membrane wall (24) and at least one flow duct is provided, which is formed between such a gas flow duct and a further such gas flow duct adjacent to the latter or an adjacent cooling unit (26) and which carries the hygroscopic solution, so that moisture, in particular water vapor, passes from the gas into the hygroscopic solution via the membrane wall and is absorbed in said solution.