Integral economizer for u-tube generator

Claim 2

In a shell-and-tube heat exchanger for the generation of vapor by the indirect transfer of heat from a heating fluid to a vaporizable liquid including a pressure vessel enclosing a bundle of heat exchange tubes and defining a vapor generating chamber, means for circulating heating fluid through sAid tubes and means for supplying vaporizable liquid to said vapor generating chamber, the improvement comprising: a. plate means defining an economizer compartment enclosing a portion of the heat transfer surface of said tubes and dividing said vapor generating chamber into a preheat section and an evaporator section; b. means defining openings at oppositely spaced ends of said compartment for discharging preheated liquid to said evaporator section; c. said means for supplying vaporizable liquid connecting with said compartment intermediate the ends thereof; and d. means within said compartment for conducting one part of said vaporizable liquid toward one of said discharge openings and the other part toward the other of said discharge openings.

Claim 3

The improvement as recited in claim 1 wherein said tubes are arranged to provide an amount of heat transfer surface within said economizer compartment to preheat each part of said vaporizable liquid to substantially the temperature of saturation thereof.

Claim 4

The improvement as recited in claim 1 wherein said parts of vaporizable liquid are substantially equal.

Claim 5

The improvement as recited in claim 1 wherein said compartment includes a plurality of baffle plate members for directing each part of said vaporizable liquid in generally crossflow relation to the tubes extending through said compartment.

Claim 6

The improvement as recited in claim 1 wherein said tubes are disposed in generally parallel relation and conduct said heating fluid in similar directions through said compartment in substantial countercurrent relation to one of said parts of vaporizable liquid and substantial cocurrent relation to the other of said parts.

Claim 7

A shell-and-tube heat exchanger for the generation of vapor by the indirect transfer of heat from a heating fluid to a vaporizable liquid comprising: a. a generally vertically elongated cylindrical shell; b. transversely extending tube sheet means dividing the interior of said shell into a vapor generating chamber and heating fluid chamber means; c. a bundle of heat exchange tubes extending through said vapor generating chamber and having their ends attaching said tube sheet means in communication with said heating fluid chamber means for circulating heating fluid through said tubes; d. means for supplying vaporizable liquid to said vapor generating chamber; e. economizer means for preheating said vaporizable liquids including: i. a plurality of plates defining a substantially axially elongated compartment in which heat is transferred to said vaporizable liquid disposed within said vapor generating chamber and dividing the same into an evaporator section and a preheat section, ii. means defining openings adjacent the oppositely spaced ends of said compartment for discharging preheated liquid to said evaporator section, iii. said vaporizable liquid supply means connecting with said compartment intermediate the ends thereof, and iv. means within said compartment for conducting one part of said vaporizable liquid toward one of said discharge openings and the other part toward the other of said discharge openings.

Claim 8

A shell-and-tube heat exchanger for the generation of vapor by the indirect transfer of heat from a heating fluid to a vaporizable liquid comprising: a. a generally vertically elongated cylindrical shell; b. transversely extending tube sheet means dividing the interior of said shell into a vapor generating chamber and heating fluid chamber means; c. a bundle of heat exchange tubes extending through said vapor generating chamber and having their ends attaching said tube sheet means in communication with said heating fluid chamber means for circulating heating fluid through said tubes; d. means for supplying vaporizable liquid to said vapor generating chamber; e. economizer means for preheating said vaporizable liquids including: i. a plurality of plates defining a substantially axially elongated compartment in which heat is transferred to said vaporizable liquid disposed within said vapor generating chamber and dividing the same into an evaporator section and a preheat section, ii. means defining openings adjacent the oppositely spaced ends of said compartment for discharging preheated liquid to said evaporator section, iii. said vaporizable liquid supply means connecting with said compartment intermediate the ends thereof, and iv. means within said compartment for conducting one part of said vaporizable liquid toward one of said discharge openings and the other part toward the other of said discharge openings.

Claim 9

A heat exchanger as recited in claim 6 wherein said compartment is defined by plate members enclosing a portion of said tube bundle.

Claim 10

A heat exchanger as recited in claim 7 wherein said compartment is disposed in spaced apart relation to the interior surface of said shell and tube sheet to define passage means for conducting heated liquid.

Claim 11

A heat exchanger as recited in claim 8 wherein said tube bundle comprises a plurality of vertically extending, generally U-shaped tubes and including a downcomer baffle surrounding said tubes in concentrically spaced relation to the internal surface of said shell to define an annular downcomer passage.

Claim 12

A heat exchanger as recited in claim 9 wherein said economizer compartment is defined about its outer periphery by a portion of the lower end of said downcomer baffle and abouT its inner periphery by a vertically extending planar plate whose end edges attach the inner surface of said downcomer baffle.

Claim 13

A heat exchanger as recited in claim 10 wherein said compartment includes a plurality of vertically spaced, transversely extending baffle plate members for directing each of the parts of the flow of vaporizable liquid in generally crossflow relation to the tubes extending through said compartment.

Claim 14

A heat exchanger as recited in claim 11 including transversely extending plates defining the upper and lower ends of said compartment, said plates containing means defining openings for establishing fluid communication between the interior of said compartment and the adjacent region of said evaporator section.

Claim 15

A heat exchanger as recited in claim 12 wherein the liquid discharged from said compartment to said evaporator section is at about saturation temperature.

Claim 16

A heat exchanger as recited in claim 12 wherein the lower end of said downcomer shroud is vertically spaced from the adjacent tube sheet and the lower end of said downcomer passage is in open fluid communication with said evaporator section adjacent the lower end of said compartment.

Claim 17

A heat exchanger as recited in claim 10 including means forming a plenum disposed about at least a portion of said downcomer baffle, means connecting said vaporizable liquid supply means to said plenum, and means forming openings in said downcomer baffle for passing vaporizable liquid from said plenum to the interior of said compartment.

Claim 18

A heat exchanger as recited in claim 15 wherein said openings are circumferentially spaced about substantially the entire length of said downcomer baffle that is common with said plenum and said compartment.