US4279768A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Service descaler for aqueous systems
Assignee: Fremont Industries Inc
•
Filing: 1980-02-04
•
Granted: 1981-07-21
•
Expires: 2000-02-04
Abstract
Abstract A scale removing formulation designed to remove scale build-up on metallic working surfaces, the scale being conventional and composed of calcium salts and iron oxides from aqueous systems such as boilers, cooling towers, heat exchangers, and the like, while those systems are in service. The present invention utilizes a synergistic blend of a chelant, polymeric conditioners and a gluconate. Principle components of the formulation of the invention include a chelant, polymeric conditioners, a gluconate, a triazole, and sodium sulfite. The gluconate is utilized as an inhibitor for ferrous metal surfaces, with the triazole being utilized as an inhibitor for non-ferrous metal surfaces. The sodium sulfite is employed for removal of dissolved oxygen.
Inventors
- 👤 Bruce D. Busch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:56
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/24; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/12
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
117 words
An in-service descaler for heat transfer surfaces consisting essentially of a composition having the following formulation: ______________________________________
Component Percent by Weight
______________________________________
A chelating agent selected
from the group consisting
of tetrasodium ethylene
diamine tetra acetic acid and
tetrasodium nitrotriacetate
monohydrate and mixtures
thereof based upon a 40%
aqueous solution 5.0 to 40.0
Polyacrylamide having a
molecular weight of
about 8000 0.1 to 5.0
Polyacrylamide having a
molecular weight of
about 1000 0.1 to 5.0
Benzotriazole 0 to 2.0
Sodium gluconate 1.0 to 10
Sodium sulfite 0.0 to 10
Water balance
______________________________________ wherein said formulation is present in an aqueous solution in a range from between about 1 part to 1000 to 5000 parts of system water.
Claim 2
Dependent Claim
117 words
An in-service descaler for heat transfer surfaces consisting essentially of a composition having the following formulation: ______________________________________
Component Percent by Weight
______________________________________
A chelating agent selected
from the group consisting
of tetrasodium ethylene
diamine tetra acetic acid and
tetrasodium nitrotriacetate
monohydrate and mixtures
thereof based upon a 40%
aqueous solution 5.0 to 40.0
Polyacrylamide having a
molecular weight of
about 8000 0.1 to 5.0
Polyacrylamide having a
molecular weight of
about 1000 0.1 to 5.0
Benzotriazole 0 to 2.0
Sodium gluconate 1.0 to 10
Sodium sulfite 0.0 to 10
Water balance
______________________________________ wherein said formulation is present in an aqueous solution in a range from between about 1 part to 1000 to 5000 parts of system water.
Claim 3
Dependent Claim
18 words
The composition as defined in claim 1 wherein said chelating agent is tetrasodium ethylene diamine tetra acetic acid.
Claim 4
Dependent Claim
77 words
The composition as defined in claim 2 wherein said composition has the formulation: ______________________________________
Component Percent by Weight
______________________________________
A chelating agent selected
from the group consisting
of tetrasodium ethylene
diamine tetra acetic acid and
tetrasodium nitrotriacetate
monohydrate and mixtures
thereof based upon a 40%
aqueous solution 20.0
Polyacrylamide having a
molecular weight of
about 8000 0.50
Polyacrylamide having a
molecular weight of
about 1000 0.50
Benzotriazole 0.20
Sodium gluconate 2.00
Sodium sulfite 3.00
Water balance
______________________________________
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) | 1984-07-20 | 1985-01-19 | 1985-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-20 | 1989-01-19 | 1989-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-20 | 1993-01-19 | 1993-07-21 | $7700.00 | Window Closed / Lapsed |