System of thermal recovery relating to the operation of a dissolver of a chemical recovery boiler
First Claim
1. A system for recovering heat from the operation of a dissolver of a chemical recovery boiler, the system comprising:
- the chemical recovery boiler;
the dissolver in which smelt is dissolved in weak white liquor to produce green liquor;
a smelt feed line via which smelt from the chemical recovery boiler is conveyed into the dissolver;
a primary fluid circuit configured for;
i. conveying green liquor from the dissolver into an external process, andii. conveying weak white liquor from the external process to the dissolver;
a secondary fluid passageway configured for conveying part of the weak white liquor diverted from the primary fluid circuit into the dissolver;
a heat exchanger in the secondary fluid passageway for recovering heat from and thereby cooling the weak white liquor diverted from the primary fluid circuit and running through the secondary fluid passageway; and
devices for transferring recovered heat from the heat exchanger to a heat consuming process, wherein;
the primary fluid circuit comprises;
a first fluid passageway configured to alternate between i. conveying green liquor from the dissolver into the external process and ii. conveying weak white liquor from the external process to the dissolver; and
a second fluid passageway configured to alternate between i. conveying green liquor from the dissolver into the external process and ii. conveying weak white liquor from the external process to the dissolver,in a first state of the primary fluid circuit the first fluid passageway is configured to convey green liquor from the dissolver into the external process while the second fluid passageway is conveying weak white liquor from the external process to the dissolver,in a second state of the primary fluid circuit the second fluid passageway is configured to convey green liquor from the dissolver into the external process while the first fluid passageway is conveying weak white liquor from the external process to the dissolver, anda valve arrangement is provided for connecting the primary fluid circuit to the secondary fluid passageway, the valve arrangement being configured to controllably divert weak white liquor from the primary fluid circuit to the secondary fluid passageway, the valve arrangement being further configured to alternate between i. diverting, in the second state, weak white liquor from the first fluid passageway of the primary fluid circuit to the secondary fluid passageway and ii. diverting, in the first state, weak white liquor from the second fluid passageway of the primary fluid circuit to the secondary fluid passageway.
1 Assignment
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Accused Products
Abstract
The disclosed solution relates to recovering thermal energy from the operation of a dissolver of a chemical recovery boiler used in pulp manufacturing. According to the solution, a primary fluid circuit conveys green liquor from the dissolver to an external process such as causticizing and solvent such as weak white liquor back to the dissolver, and from this circuit solvent is diverted into a secondary fluid passageway comprising a heat exchanger which cools the solvent by recovering heat from it and transfers the heat to a heat-consuming process. After heat recovery, solvent may be used for further processes before it is at least partly conveyed back to the dissolver.
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Citations
6 Claims
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1. A system for recovering heat from the operation of a dissolver of a chemical recovery boiler, the system comprising:
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the chemical recovery boiler; the dissolver in which smelt is dissolved in weak white liquor to produce green liquor; a smelt feed line via which smelt from the chemical recovery boiler is conveyed into the dissolver; a primary fluid circuit configured for; i. conveying green liquor from the dissolver into an external process, and ii. conveying weak white liquor from the external process to the dissolver; a secondary fluid passageway configured for conveying part of the weak white liquor diverted from the primary fluid circuit into the dissolver; a heat exchanger in the secondary fluid passageway for recovering heat from and thereby cooling the weak white liquor diverted from the primary fluid circuit and running through the secondary fluid passageway; and devices for transferring recovered heat from the heat exchanger to a heat consuming process, wherein; the primary fluid circuit comprises; a first fluid passageway configured to alternate between i. conveying green liquor from the dissolver into the external process and ii. conveying weak white liquor from the external process to the dissolver; and a second fluid passageway configured to alternate between i. conveying green liquor from the dissolver into the external process and ii. conveying weak white liquor from the external process to the dissolver, in a first state of the primary fluid circuit the first fluid passageway is configured to convey green liquor from the dissolver into the external process while the second fluid passageway is conveying weak white liquor from the external process to the dissolver, in a second state of the primary fluid circuit the second fluid passageway is configured to convey green liquor from the dissolver into the external process while the first fluid passageway is conveying weak white liquor from the external process to the dissolver, and a valve arrangement is provided for connecting the primary fluid circuit to the secondary fluid passageway, the valve arrangement being configured to controllably divert weak white liquor from the primary fluid circuit to the secondary fluid passageway, the valve arrangement being further configured to alternate between i. diverting, in the second state, weak white liquor from the first fluid passageway of the primary fluid circuit to the secondary fluid passageway and ii. diverting, in the first state, weak white liquor from the second fluid passageway of the primary fluid circuit to the secondary fluid passageway. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification