Method and apparatus for temperature control in a reactor vessel

Patent metadata

Field	Value
Publication number	US-9322076-B2
Application number	US-201113009223-A
Country	US
Kind code	B2
Filing date	Jan 19, 2011
Priority date	Jul 24, 2008
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A method and apparatus for controlling a temperature within a reactor vessel such as an autoclave operating at elevated temperature and pressure. The apparatus includes a preheating vessel for preheating a feed material such as an aqueous slurry. The preheating vessel forms part of a preheating control system providing the primary means of temperature control within the reactor vessel. The apparatus also comprises secondary means for heating and cooling the reactor. Feed material temperature is increased or decreased by the preheating control system, based on the reactor temperature. Where the preheating control system is at or near its capacity for heating or cooling, the secondary heating or cooling means is activated to bring the reactor temperature within an optimum range.

First claim

What is claimed is:

1. A method for controlling a temperature within a reactor vessel, comprising:
(a) preheating at least a portion of a feed material with a first heating medium in a heating section of a preheating vessel, wherein the preheating vessel comprises:
a first inlet adapted to receive at least a portion of the feed material;
an outlet adapted to discharge the feed material to the reactor vessel;
a second inlet adapted to receive the first heating medium;
a heating section in which feed material entering said preheating vessel through said first inlet is heated by contact with the first heating medium, wherein said first inlet is located relative to said heating section such that feed material entering said preheating vessel through said first inlet is heated by contact with the first heating medium;
a collection section downstream of said heating section, wherein feed material heated in said heating section is collected in said collection section, and wherein said outlet is adjacent to said collection section; and

a third inlet adapted to receive at least a portion of the feed material, wherein said third inlet is located relative to said heating section such that feed material entering said preheating vessel through said third inlet at least partially bypasses said heating section;
(b) discharging the feed material from an outlet of the preheating vessel to an inlet of the reactor vessel;
(c) sensing the temperature within the reactor vessel with a temperature sensing device adapted to measure a temperature within the reactor vessel and generate a corresponding reactor temperature signal;
(d) using a controller to determine whether the temperature within the reactor vessel is to be increased or decreased, wherein the controller is programmed to receive said reactor temperature signal and determine whether the temperature within the reactor vessel is to be increased or decreased, wherein:
said controller is programmed to control the operation of a preheating control valve in response to said reactor temperature signal so as to increase or decrease the temperature at which the feed material is discharged, wherein the preheating control valve is located upstream of said preheating vessel, wherein said preheating control valve comprises an inlet adapted to receive at least a portion of the feed material and an outlet in flow communication with said third inlet of said preheating vessel, the preheating control valve being operable to adjust the relative proportions of feed material entering said preheating vessel through said first inlet and said third inlet;
said controller is programmed to control the operation of a reactor heating control system to supply a second heating medium to the reactor vessel in an amount sufficient to increase the temperature within the reactor vessel, wherein the reactor heating control system is adapted to supply a controlled amount of the second heating medium to the reactor vessel to thereby increase the temperature within the reactor vessel; and
said controller is programmed to control the operation of a reactor cooling control system to supply a cooling medium to the reactor vessel in an amount sufficient to decrease the temperature within the reactor vessel, wherein the reactor cooling control system is adapted to supply a controlled amount of the cooling medium to the reactor vessel to thereby decrease the temperature within the reactor vessel; and

(e) where it is determined in step (d) that the temperature within the reactor vessel is to be increased:
(i) increasing the preheating of the feed material by an amount sufficient to increase a temperature at which the feed material enters the reactor vessel; or
(ii) where the preheating of the feed material has been increased to a maximum level, supplying the controlled amount of the second heating medium to the reactor vessel so as to increase the temperature within the reactor vessel;

(f) where it is determined in step (d) that the temperature within the reactor vessel is to be decreased:
(i) decreasing the preheating of the feed material by an amount sufficient to decrease a temperature at which the feed material enters the reactor vessel; or
(ii) where the preheating of the feed material has been decreased to a minimum level, supplying the controlled amount of the cooling medium to the reactor vessel so as to decrease the temperature within the reactor vessel.

2. The method of claim 1 , wherein the preheating of the feed material is increased or decreased by increasing or decreasing an amount of said feed material which at least partially bypasses the heating section of the preheating vessel.

3. The method of claim 2 , wherein the maximum level of preheating is reached when the amount said feed material which at least partially bypasses the heating section is at or near a minimum amount.

4. The method of claim 2 , wherein the minimum level of preheating is reached when the amount of said feed material which at least partially bypasses the heating section is at or near a maximum amount.

5. The method of claim 1 , wherein the reactor vessel is an autoclave operating at elevated temperature and pressure, the feed material is an aqueous slurry of minerals or metal-containing compounds to be oxidized or leached inside the autoclave, the first heating medium is steam, the cooling medium is water, and the second heating medium is steam and/or a reagent which reacts exothermically with the minerals or metal-containing compounds of the slurry.

6. An apparatus for controlling a temperature within a reactor vessel, the apparatus comprising:
(a) a preheating vessel comprising:
a first inlet adapted to receive at least a portion of a feed material;
an outlet adapted to discharge the feed material to the reactor vessel;
a second inlet adapted to receive a first heating medium;
a heating section in which feed material entering said preheating vessel through said first inlet is heated by contact with the first heating medium, wherein said first inlet is located relative to said heating section such that feed material entering said preheating vessel through said first inlet is heated by contact with the first heating medium;
a collection section downstream of said heating section, wherein feed material heated in said heating section is collected in said collection section, and wherein said outlet is adjacent to said collection section; and
a third inlet adapted to receive at least a portion of the feed material, wherein said third inlet is located relative to said heating section such that feed material entering said preheating vessel through said third inlet at least partially bypasses said heating section;

(b) a preheating control valve located upstream of said preheating vessel, wherein said preheating control valve comprises an inlet adapted to receive at least a portion of the feed material and an outlet in flow communication with said third inlet of said preheating vessel, the preheating control valve being operable to adjust the relative proportions of feed material entering said preheating vessel through said first inlet and said third inlet;
(c) a temperature sensing device adapted to measure a temperature within the reactor vessel and generate a corresponding reactor temperature signal;
(d) a reactor heating control system adapted to supply a controlled amount of a second heating medium to the reactor vessel to thereby increase the temperature within the reactor vessel;
(e) a reactor cooling control system adapted to supply a controlled amount of a cooling medium to the reactor vessel to thereby decrease the temperature within the reactor vessel; and
(f) a controller programmed to: receive said reactor temperature signal; and determine whether the temperature within the reactor

Assignees

• Fraser Kevin S
• Pearson Murray S
• Mccombe William E
• Hatch Ltd

Inventors

• Fraser Kevin S
• Pearson Murray S
• Mccombe William E

Classifications

• Y02P10/20

  Recycling · CPC title

• F27D19/00

  Arrangements of controlling devices · CPC title

• F27B15/18

  Arrangements of controlling devices · CPC title

• G05D23/1393

  characterised by the use of electric means · CPC title

• G05D23/1931

  to control the temperature of one space · CPC title