EP0172649A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Dewatering solids suspensions
Assignee: Water Research Centre
•
Filing: 1985-07-15
•
Granted: —
•
Expires: 2005-07-15
Abstract
Abstract In filter plate (15) pressing of solids suspensions, the suspensions are mixed with flocculant downstream of the press feed pump(s) (11), the dose of flocculant being determined over at least a major part of the press cycle from the speed of the press feed pump(s) the or each of which is of the positive displacement type. The flocculant is preferably pumped to a mixer (14) (wherein it is added to the solids suspension) using at least one positive displacement pump (24).
Inventors
- 👤 Garry Hoyland
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 20:39
CPC Classifications
C; C02; C02F; C02F11/00; C02F11/12; C02F11/121; C02F11/122; B; B01; B01D; B01D37/00; B01D37/03; B01D37/04; B01F; B01F27/00; B01F27/60; B01F27/70; C02F1/00; C02F1/52; C02F1/5209; C02F1/68; C02F1/685; C02F1/686; B01F2101/00; B01F2101/305; B01F25/00; B01F25/60; B01F25/64; B01F27/05; B01F27/11; B01F27/112; B01F27/1125
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
68 words
A method of dewatering a solids suspensior. wherein a flocculant is added to the suspension and the mixture is subjected to filter pressing, the flocculant being added downstream of the press feed pump, wherein the press feed pump is a positive displacement pump and the amount of flocculant added to the suspension is controlled, for at least part, in dependence on the speed of the press feed pump.
Claim 2
Independent Claim
68 words
A method of dewatering a solids suspensior. wherein a flocculant is added to the suspension and the mixture is subjected to filter pressing, the flocculant being added downstream of the press feed pump, wherein the press feed pump is a positive displacement pump and the amount of flocculant added to the suspension is controlled, for at least part, in dependence on the speed of the press feed pump.
Claim 3
Dependent Claim
24 words
A method according to claim 1, wherein two or more press feed pumps are used to maintain high pump speeds throughout a press cycle.
Claim 4
Dependent Claim
25 words
A method according to claim 1 or 2, wherein at least one positive displacement pump is used to feed flocculant into admixture with the suspension.
Claim 5
Dependent Claim
41 words
A method according to claim 1,2 or 3, wherein the suspension is mixed with flocculant by passing both radially into a cylindrical chamber comprising one or more rotating impellers therein, the mixture exiting from one end of the chamber axially thereof.
Claim 6
Dependent Claim
50 words
A method according to claim 1 wherein when, during the dewatering process, the suspension flowrate from the press feed pump is low compared with the maximum duty of the pump, the amount of flocculant added to the suspension is controlled in dependence on the flowrate as determined using a flowmeter.
Claim 7
Dependent Claim
94 words
Apparatus for dewatering a solids suspension by filter pressing, which comprises a. filter press (15), a feed pump (11) for pumping said suspension to the filter press, means (14) for mixing flocculant with the suspension downstream of the feed pump, means for sensing the flowrate of the suspension to the filter press, and means for controlling the amount of flocculant mixed with the suspension in dependence on the sensed flowrate; wherein the or each feed pump is a positive displacement pump and said sensing means comprises means for sensing the speed of the pump.
Claim 8
Dependent Claim
94 words
Apparatus for dewatering a solids suspension by filter pressing, which comprises a. filter press (15), a feed pump (11) for pumping said suspension to the filter press, means (14) for mixing flocculant with the suspension downstream of the feed pump, means for sensing the flowrate of the suspension to the filter press, and means for controlling the amount of flocculant mixed with the suspension in dependence on the sensed flowrate; wherein the or each feed pump is a positive displacement pump and said sensing means comprises means for sensing the speed of the pump.
Claim 9
Dependent Claim
30 words
Apparatus according to claim 5, wherein two or more feed pumps of different size are included so as to be able to maintain high pump speeds throughout a press cycle.
Claim 10
Dependent Claim
46 words
Apparatus according to claim 6 or 7, wherein mixing means (14) comprises a cylindrical chamber (51) having an axial outlet at one end (52) for the mixture and radial inlets (80,81,82) for the suspension and flocculant, the chamber including one or more rotatable plate-like impellers (55,56,57).
Claim 11
Dependent Claim
23 words
Apparatus according to claim 6,7, or 8, wherein two or more positive displacement pumps (24) are included for pumping flocculant to the mixer.
Claim 12
Dependent Claim
41 words
Apparatus according to claim 6, wherein there is also included, downstream or upstream of the pump, a flowmeter (13) to measure said flowrate when the latter drops to levels that are low compared with the maximum duty of the feed pump(s).
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.