Title:
Waste pickle liquor disposal
United States Patent 2350095


Abstract:
This invention is concerned with the problem of neutralizing waste pickle liquor with a basic solution to render the liquor fit for disposal, the object being to do this in an economical manner so as to produce a smooth mixture capable of being pumped through a pipe to disposal equipment. ...



Inventors:
Carlson, Earl C.
SHARP DOUGLAS F
Application Number:
US42784142A
Publication Date:
05/30/1944
Filing Date:
01/22/1942
Assignee:
Carlson, Earl C.
SHARP DOUGLAS F
Primary Class:
Other Classes:
210/738, 210/919, 366/263, 422/225
International Classes:
B01F5/16; C02F9/00
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Description:

This invention is concerned with the problem of neutralizing waste pickle liquor with a basic solution to render the liquor fit for disposal, the object being to do this in an economical manner so as to produce a smooth mixture capable of being pumped through a pipe to disposal equipment.

Waste pickle liquor results from the practice of pickling steel products with an acid pickle liquor; usually a sulphuric acid solution of sufficent strength to remove oxides from the steel.

This liquor becomes a waste product when its metallic salt content increases and its acid content decreases to points where pickling becomes uneconomically slow. This waste product must then be neutralized since its acid content is still too high to otherwise permit its disposal.

According to the prior art, this neutralization is effected by mixing the waste pickle liquor with a lime suspension in tanks, the mixture being agitated to promote the necessary reaction. The Waste pickle liquor contains various impurities and is a rather complex product, large volumes of intermediate products being formed during 25 the neutralization which precipitate to form a heavy sludge. In addition, clots and heavy lumps are formed when the lime suspension Is mixed with the waste pickle liquor. As a result of these complications, it is necessary to unduly prolong 3 the agitation of the mixture if the reaction is to be carried to completion. In actual practice an excess of lime is used in an effort to shorten the agitation period, but this is an extravagant procedure. In any event, it Is practically im- 31 possible to produce a neutralized product that is sufficiently smooth in consistency to permit its being pumped through a pipe without difficulty.

According to the present invention, these objectionable features of the prior art practice are 4 eliminated by feeding separated flows of- the waste pickle liquor and the basic solution, such as the lime suspension, into the central intake of a centrifugal pump and there bringing them together while the pump is working so they are 4 violently Intermixed immediately upon their coming together. Under these conditions the mixture reacts without lumping or clotting and is forced by the pump through its discharge as a substantially neutral product fit for diqspcsal and of a smooth consistency which can be pumped through a pipe without difficulty. Any centrifugal pump may be used providing the-two materials are fed to its central intake by separate pipes arranged to bring the two materials I together closely adjacent the central portion of the pump's impeller.

It has been found that the mixture resulting from the above has a maximum viscosity when the proper amounts of the waste pickle liquor and the *line suspension are used to just ieffect complete neutralization. The viscosity lowers when there is an excess either of the liquor or of the basic solution. Therefore, the above procedure permits very nice proportioning of the two materials, the separate flows being Ć½regulated as required to produce a product of maximum viscosity. The proportioning may be conveniently carried out by observing the working load on the pump, the relative volumes of the liquor and of the basic solution brought together being proportioned to place a maximum working load on the pump so as to assure complete reaction without an excess of either of the mixed materials.

The accompanying drawing schematically illustrates a centrifugal pump of the type adapted to carry out the present invention; More specifically, this drawing shows a valved waste pickle liquoriconduit I, and a valved lime suspension line 2, both leading to the .central intake 3 of a centrifugal pump having an Impeller 4, suitably driven at high speed, and an outlet 5. A valved water inlet 6 is provided for the purpose of priming the pump at the start of operations. It is to be noted that the conduits I and 2 both open directly at the central intake 3 of the pump, on the same side of its-impeller , and that the two continue to completely separate the waste pickle liquor and the lime suspension until they are brought together at this intake. -The load on the impeller 4 may be measured by any suitable torque measuring device.

0 We claim: 1. A method of neutralizing waste pickle liquor with a basic solution to render the liquor fit for disposal, said method being characterized by feeding separated flows of the liquor and (the L5 basic solution into the central intake of a centrifugal pump and there bringing them together while the pump is working so they are violently intermixed immediately upon their coming together, the mixture reacting without lumping or 50 clotting and being forced by the pump through its discharge to create a smooth flow of a substantally neutral product fit for disposal.

2. A method of neutralizing waste pickle liquor with a basic solution-to render the liquor f~ for 55 disposal, said method being characterized by feeding separated flows of the liquor and the basic solution into the central intake of a centrifugal pump and there bringing them together while the pump is working so they are violently intermixed immediately upon their coming together, the mixture reacting without lumping or clotting and being forced by the pump through its discharge to create a smooth flow of a substantially neutral product fit for disposal, the relative volumes of the liquor and of the basic solution brought together being proportioned to place a maximum working load on the pump.

3. A method of neutralizing waste pickle liquor with a basic solution to render the liquor fit for disposal, said method being characterized by s1 feeding separated flows of the liquor and the basic solution into the central Intake of a centrifugal pump and there bringing them together while the pump Is working so they are violently intermixed Immediately upon their coming together, the mixture reacting without lumping or clotting and being forced by the pump through its discharge to create a smooth flow of a substantially neutral product fit for disposal, the relative volumes of the liquor and of the basic solution brought together beidg proportioned to produce a product of maximum viscosity.

EARL C. CARLSON.

DOUGLAS F. SHARP.