Wieland-werke Ag

Andreas Schwitalla

Andreas Beutler

Gerhard Schuez

Ronald Lutz

Manfred Knab

Achim Gotterbarm

Andreas Knoepfler

Markus Revermann

Jean El Hajal

Jianying Cao

Zhong Luo

Karine Brand

Axel Kriegsmann

Klaus Menze

Christian Rettich

Jochen Dietl

Guenter Fetzer

Martin Weixler

Andreas Knöpfler

A metal heat exchanger tube for the evaporation of liquids on the outside of the tube, having a tube axis, a tube wall, and integrally formed ribs that run circumferentially on the outside of the tube. The ribs have a rib foot, rib flanks, and a rib tip, wherein the rib foot projects substantially radially from the tube wall. A respective groove is located between every two ribs that are adjacent to one another in the axial direction. At least first, second, and third lateral material projections, which are formed from the material of the ribs, are arranged on a first, second, and third level on the rib flanks in such a way that the grooves are largely covered by all of the material projections. The first, second, and third lateral material projections are formed on levels that are in each case differently spaced apart from the tube wall in the radial direction.

Evaporator tube having an optimised external structure

An evaporation heat transfer tube has a tube main body and a step-like structure; outer fins are arranged at intervals on the outer surface of the tube main body and an inter-fin groove is formed between two adjacent outer fins; the step-like structure respectively abuts against the bottom plane and one of the side walls of the inter-fin groove. The step-like structure has a first surface, a second surface and at least one flange formed by the intersection of the two surfaces, wherein the first and the second surface intersect respectively with the side wall and the bottom plane.

Evaporation heat transfer tube

The present invention relates to an evaporation heat transfer tube with a hollow cavity, comprising a tube main body and at least one hollow frustum structure. Outer fins are arranged at intervals on the outer surface of the tube main body and inter-fin grooves are formed between two adjacent outer fins. The hollow frustum structure is arranged at the bottom of the inter-fin grooves and surrounded by side walls. The top of the hollow frustum structure is provided with an opening. The side walls extend inwards and upwards from the bottom of the inter-fin grooves and thus the area of the opening is less than the area of the bottom of the hollow frustum structure. The inner surface and the outer surface of the side walls are intersected at the opening to form a flange. Preferably, the flange is a sharp corner and the radius of the curvature is 0 to 0.01 mm. The side walls are formed by at least two surfaces which are connected to each other. The hollow frustum structure is hollow pyramid frustum shaped, hollow volcano shaped or hollow cone frustum shaped. The height Hr and the height H of the inter-fin grooves meet the following relations: Hr/H is greater than or equal to 0.2. The present invention is ingeniously designed and concisely structured and it remarkably enhances the boiling coefficient between the outer surface of the tube and the liquid outside the tube, reinforcing the heat transfer in boiling and it is suitable for large-scale popularization and application.

Evaporation heat transfer tube with a hollow cavity

The invention relates to a heat exchanger tube with at least one structured region on the inside of the tube, which has the following features: A further aspect of the invention relates to a method for producing heat exchanger tubes of this type, with integral external ribs running around the outside of the tube in a helical-line-shaped manner and running on the inside of the tube in an axially parallel or helical-line-shaped manner, and internal ribs which are crossed and notched by secondary grooves and by tertiary grooves.

Structured heat exchanger tube and method for the production thereof

A metallic heat exchanger tube has fins which run helically around the outside of the tube, are molded integrally therefrom and are of continuous design and the fin base of which protrudes substantially radially from the tube wall, and with primary grooves located between respectively adjacent fins. At least one undercut secondary groove is arranged in the region of the groove base of the primary grooves. The secondary groove is delimited toward the primary groove by a pair of mutually opposite material projections formed from the material of respectively adjacent fin bases and the cross-section thereof is varied at regular intervals without having an influence on the shape of the fins. There is a spacing between the opposite material projections, the spacing being varied at regular intervals, as a result of which local cavities are formed.

Evaporator tube with optimized undercuts on the groove base

A metallic heat transfer tube, in particular for the evaporation of liquids from pure substances or mixtures on the outside of the tube. Fins are integrally formed on the outside of the tube. Recesses are arranged in the area of the base of the primary grooves and extend between the fins. The recesses are in the form of re-entrant secondary grooves. The mechanical stability of the tube is not negatively influenced because material is primarily removed from the fin flanks toward the base of the groove so that the re-entrant secondary grooves are radially open.

Heat transfer tube and a method of fabrication thereof

Method of fabricating a heat exchanger tube

The invention relates to heat-exchanger tubes structured on both inner and outer sides with excellent heat-transfer characteristics, which have recesses on the outside and ribs with specific dimensions on the inside. The structuring tools utilized for the various method modifications are adjusted in such a manner that they are not only able to create aligned, continuous grooves and non-aligned, spaced apart recesses but also secondary structures. The heat-exchanger tubes provided preferably with smooth end sections and smooth intermediate sections are utilized in particular in shell and tube heat-exchangers.

Heat-exchanger tube structured on both sides and a method for its manufacture

The invention relates to a heat-transfer tube, in particular an evaporator tube, with fins circumferentially extending on the shellside, which fins are shaped to essentially closed-off channels. The channels are open to the outside through pores with at least two variable sizes. In order to improve the evaporation characteristics, the invention provides advantageous regions for the ratio of the pore sizes and the ratio of the number of pores.

Heat transfer tube for evaporation with variable pore sizes

A process for producing a heat exchanger tube (1) with a highly porous surface structure, in particular for evaporating liquids from pure substances or mixtures on the outside of the tube. The process starts from a rolling operation, by means of which helical fins (2) are produced on the outside of the tube, which fins, in turn, are deformed in a plurality of compression steps by means of gearwheel-like compression wheels (6, 7) in such a manner that the projections (12a, 12b) formed in each case form a cover (3a) for the passages (3) which are situated between the fins (2). The high level of porosity is achieved as a result of the remaining pores (13) and/or slots (14).

Growing community of inventors

Voehringen, Germany

Andreas Schwitalla