US4526713A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and system for treatment of radioactive waste
Assignee: Hitachi Ltd
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Filing: 1981-01-12
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Granted: 1985-07-02
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Expires: 2001-01-12
Abstract
Abstract In a treatment system of radioactive waste solution including sodium sulfate generated from a boiling water type nuclear reactor, waste solution is fed into a thin film evaporator where the waste solution is evaporated and made into powder while precipitating in a peripheral surface of the evaporator vessel. The surface of the precipitated solid is wiped by rotating wiper blades and removed off as radioactive solid powder. The rotational speed of a rotor to which the wiper blades are secured is controlled at a minimum and necessary rotational speed which contributes to make the waste solution into the powder so that the rate of worn out of the wiper blade is decreased.
Inventors
- 👤 Koichi Chino
- 👤 Kazuhiko Kudo
- 👤 Akira Oda
- 👤 Hideichi Mura
- 👤 Yoshiyuki Takamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:11
CPC Classifications
B; B01; B01D; B01D1/00; B01D1/22; B01D1/222; B01D1/223; B01D1/225; G; G21; G21F; G21F9/00; G21F9/04; G21F9/06; G21F9/08; Y; Y10; Y10S; Y10S159/00; Y10S159/12
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
116 words
A process for treatment of waste liquid material including dissolved radioactive substances, comprising: heating the waste liquid material to vaporize the liquid and to deposit said radioactive substances on a heat transfer surface; wiping the radioactive substances deposited on the heat transfer surface to form a dry powder by rotary wiping blades; measuring the flow rate (W) of the entering waste liquid material and the concentration (C) of the radioactive substances to be powdered in the waste liquid material, thus determining the quantity of the radioactive substances to be powdered by the product of (W×C); and controlling the rotational speed of the wiping blade in accordance with the quantity of the radioactive substances to be powdered.
Claim 2
Dependent Claim
116 words
A process for treatment of waste liquid material including dissolved radioactive substances, comprising: heating the waste liquid material to vaporize the liquid and to deposit said radioactive substances on a heat transfer surface; wiping the radioactive substances deposited on the heat transfer surface to form a dry powder by rotary wiping blades; measuring the flow rate (W) of the entering waste liquid material and the concentration (C) of the radioactive substances to be powdered in the waste liquid material, thus determining the quantity of the radioactive substances to be powdered by the product of (W×C); and controlling the rotational speed of the wiping blade in accordance with the quantity of the radioactive substances to be powdered.
Claim 3
Dependent Claim
25 words
A process according to claim 1, wherein the rotational speed is controlled at a minimum speed necessary for powderizing the radioactive substances to be treated.
Claim 4
Dependent Claim
30 words
A process according to claim 1 or 2, wherein the rotational speed changes in proportion to the rate of change in the maximum quantity of radioactive substances to be powdered.
Claim 5
Dependent Claim
72 words
A process according to claim 3, wherein evaporation of the liquid and depositing of the radioactive substances on a heat transfer surface changes from a point where the maximum quantity of the radioactive substances to be powderized increases effectively with the increase of the wiping speed to a point where the maximum quantity of the radioactive substances to be powderized increases at a negligible rate with the increase of the wiping speed.
Claim 6
Dependent Claim
34 words
A process according to claim 4, further comprising steps of detecting a quantity of the waste liquid material to be treated and detecting a concentration of the radioactive substances in the waste liquid material.
Claim 7
Dependent Claim
46 words
A process according to claim 5, further comprising a step of calculating the maximum quantity of radioactive substances to be treated by an equation of thermal balance of heat energy required to vaporize water content in the waste liquid material and heat energy supplied for heating.
Claim 8
Dependent Claim
34 words
A process according to claim 3, further comprising steps of detecting a quantity of the waste liquid material to be treated and detecting a concentration of the radioactive substances in the waste liquid material.
Claim 9
Dependent Claim
46 words
A process according to claim 7, further comprising a step of calculating the maximum quantity of radioactive substances to be treated by an equation of thermal balance of heat energy required to vaporize water content in the waste liquid material and heat energy supplied for heating.
Claim 10
Dependent Claim
45 words
A process according to claim 1, wherein the wiping speed is kept constant and the flow rate of the waste liquid material and the concentration of the radioactive substances to be powderized in the waste liquid material are controlled to obtain an optimum operation condition.
Claim 11
Dependent Claim
34 words
A process according to claim 9, further comprising steps of detecting a quantity of the waste liquid material to be treated and detecting a concentration of the radioactive substances in the waste liquid material.
Claim 12
Independent Claim
158 words
A system for treatment of waste liquid material including dissolved radioactive substances comprising a film evaporator having a cylindrical vessel with an inlet and outlet for the waste liquid material heating means for heating the waste liquid material in said vessel through a cylindrical heat transfer surface of said vessel to vaporize the liquid and to deposit said radioactive substances on the heat transfer surface, wiping means for wiping said heat transfer surface to remove the radioactive substances depositing thereon to obtain dry powder of the radioactive substances, measuring means for measuring the flow rate (W) of the entering waste liquid material and the concentration (C) of the radioactive substances to be powdered in the waste liquid material and determining the quantity of the radioactive substances to be powdered by the product of (W×C); and control means for controlling the wiping speed of said wiping means in accordance with the quantity of the radioactive substances to be powdered.
Claim 13
Independent Claim
158 words
A system for treatment of waste liquid material including dissolved radioactive substances comprising a film evaporator having a cylindrical vessel with an inlet and outlet for the waste liquid material heating means for heating the waste liquid material in said vessel through a cylindrical heat transfer surface of said vessel to vaporize the liquid and to deposit said radioactive substances on the heat transfer surface, wiping means for wiping said heat transfer surface to remove the radioactive substances depositing thereon to obtain dry powder of the radioactive substances, measuring means for measuring the flow rate (W) of the entering waste liquid material and the concentration (C) of the radioactive substances to be powdered in the waste liquid material and determining the quantity of the radioactive substances to be powdered by the product of (W×C); and control means for controlling the wiping speed of said wiping means in accordance with the quantity of the radioactive substances to be powdered.
Claim 14
Dependent Claim
17 words
A system according to claim 11, further comprising detecting means for the quantity of the radioactive substances.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-01 | 1988-12-31 | 1989-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-01 | 1992-12-31 | 1993-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-01 | 1996-12-31 | 1997-07-02 | $7700.00 | Window Closed / Lapsed |