Advantageous configuration of tubing for internal boiling

Claim 3

The method as defined in claim 1 in which the tubing has a wall thickness of not more than 0.075 inch.

Claim 4

The method as defined in claim 2 in which the wall of the tubing intermediate said rib and groove convolutions has a smooth cylindrical surface.

Claim 5

The method as defined in claim 1 in which the ribbing convolutions are helical.

Claim 6

The method as defined in claim 4, in which said ribbing consists of a single helical rib.

Claim 7

The method as defined in claim 4, in which the ribbing consists of a plurality of helical ribs.

Claim 8

The method as defined in claim 1 in which the ribbing convolutions consist of a multiplicity of separate annular ribs.

Claim 9

The method as defined in claim 2 in which the ribbing convolutions are helical.

Claim 10

The method as defined in claim 2 in which the ribbing convolutions consist of a multiplicity of separate annular ribs.

Claim 11

The method as defined in claim 1 in which the outside diameter of the tubing is 3/4 inch to 1- 1/2 inch.

Claim 12

The method as defined in claim 10 in which the tubing has a wall thickness of not more than 0.075 inch.

Claim 13

The method as defined in claim 10 in which the ribbing convolutions are helical.

Claim 14

The method as defined in claim 1 in which the liquid is a halogenated hydrocarbon refrigerant such as Freon.

Claim 15

The method as defined in claim 1 which comprises controlling the flow to introduce the hydrocarbon or substituted hydrocarbon into the tubing substantially in liquid phase and effecting substantially complete vaporization within the tubing to cause exit of the hydrocarbon from the tubing substantially in vapor phase.

Claim 16

Evaporator construction comprising an enclosure, metal heat exchange tubing in said enclosure for receiving a hydrocarbon or substituted hydrocarbon refrigerant in substantially liquid phase at one end and for discharging the refrigerant in substantially vapor phase at the other, the exerior surface of said tubing being in heat exchange relation with a fluid transiting said enclosure and giving up heat to the refrigerant to vaporize substantially all of the refrigerant, the interior of said tubing being substantially unobstructed except for surface configuration, the interior surface of said tubing being provided with radially inwardly extendIng ribbing, said ribbing comprising a multiplicity of convolutions extending around the tubing, the axial pitch P of adjacent convolutions being not greater than 3/4 inch, the depth d or radial extension of said ribbing being between 1/64 inch and 3/64 inch, the ratio of pitch to depth of convolutions P/d being between 5 and 25, said tubing having a wall of substantially uniform thickness, the exterior of said tubing having a multiplicity of groove convolutions which are disposed opposite to the rib convolutions at the interior of said tubing, are of a depth substantially equal to the depth of radial extension of said ribbing, and conform thereto.

Claim 17

Evaporator construction comprising an enclosure, metal heat exchange tubing in said enclosure for receiving a hydrocarbon or substituted hydrocarbon refrigerant in substantially liquid phase at one end and for discharging the refrigerant in substantially vapor phase at the other, the exerior surface of said tubing being in heat exchange relation with a fluid transiting said enclosure and giving up heat to the refrigerant to vaporize substantially all of the refrigerant, the interior of said tubing being substantially unobstructed except for surface configuration, the interior surface of said tubing being provided with radially inwardly extendIng ribbing, said ribbing comprising a multiplicity of convolutions extending around the tubing, the axial pitch P of adjacent convolutions being not greater than 3/4 inch, the depth d or radial extension of said ribbing being between 1/64 inch and 3/64 inch, the ratio of pitch to depth of convolutions P/d being between 5 and 25, said tubing having a wall of substantially uniform thickness, the exterior of said tubing having a multiplicity of groove convolutions which are disposed opposite to the rib convolutions at the interior of said tubing, are of a depth substantially equal to the depth of radial extension of said ribbing, and conform thereto.

Claim 18

The construction as defined in claim 15 in which said tubing has a wall thickness of not more than 0.075 inch.

Claim 19

The construction as defined in claim 16 in which the wall of said tubing intermediate said rib and groove convolutions has a smooth cylindrical surface.

Claim 20

The construction as defined in claim 15, in which said ribbing convolutions are helical.

Claim 21

The construction as defined in claim 18 in which said ribbing consists of a single helical rib.

Claim 22

The construction as defined in claim 18 in which said ribbing consists of a plurality of helical ribs.

Claim 23

The construction as defined in claim 20 in which said ribbing convolutions consists of a multiplicity of separate annular ribs.

Claim 24

The construction as defined in claim 16 in which said ribbing convolutions are helical.

Claim 25

The construction as defined in claim 16, in which said ribbing convolutions consist of a multiplicity of separate annular ribs.

Claim 26

The construction as defined in claim 15 in which the outside diameter of said tubing is 1/4 inch to 1 1/2 inch.

Claim 27

The construction as defined in claim 24 in which said tubing has a wall thickness of not more than 0.075 inch.

Claim 28

The construction as defined in claim 24 in which said ribbing convolutions are helical.