Abstract: An evaporator for eliminating water from liquids or for cooling liquids by direct expansion of a refrigerant fluid, comprising at least three frusto-conical jackets which include an outer jacket, an inner jacket, and at least one intermediate jacket. Said jackets are coaxially superimposed so as to define annular spaces therebetween. The ends of the jackets are closed except the small end of the internal jacket, which is open and communicates with a chamber defined inside the inner jacket. Inlet and outlet means for a first fluid are connected with respective ends of the annular space between the outer jacket and the adjacent intermediate jacket, and inlet and outlet means for a second fluid are connected respectively to the large end of the annular space between the inner jacket and the adjacent intermediate jacket.

Abstract: A heat exchanger, especially for the processing of food or pharmaceutical products comprising at least two coaxially superimposed frusto-conical jackets defining an annular space therebetween. Inlet and outlet means for a first fluid are connected to opposite ends of said annular space, and a spacer in the form of a conical helix is freely and releasably disposed in said annular space in contact with the opposite conical surfaces thereof. The spacer and the conical surfaces defining a helical fluid channel leading from the inlet means to the outlet means. Means are provided for releasably attaching the frusto-conical jackets at their large ends and for sealing the large end of said annular space. The first fluid exchanges heat with a second fluid in contact with a surface of one of said jackets contiguous but exterior to said annular space.