US2083012A

US2083012A - Degreasing apparatus

Info

Publication number: US2083012A
Application number: US6743A
Authority: US
Inventors: Eastwood Robert Anderson
Original assignee: Imperial Chemical Industries Ltd
Current assignee: Imperial Chemical Industries Ltd
Priority date: 1934-02-15
Filing date: 1935-02-15
Publication date: 1937-06-08
Anticipated expiration: 1954-06-08

Description

DEGREASING APPARATUS Filed Feb. 15, 1935 3 Sheets-Sheet l FIG, 1

-INVENTOR.

' RuberfAnflerspnEasIwnml ATTORNEY June 8, 1937. RQA. EASTWOOYD 2,083,012

DEGREASING APPARATUS Fild Feb. 15, 1935 3 Sheets-Sheet 2 FIG. 2

INVENTOR.

Rubs-PI Anderson Eaalwund.

I ATTORNEY June 8, 1937. R A EASTWOOD 2,083,012

DEGREAS ING APPARATUS Filed Feb. 15, 1935 3 Sheet S-Sheet 3 NF \l r m 0) W :3 w 03' I E ATTORNEY Patented June 8, 1937 DEGREASING APPARATUS Robert Anderson Eastwood, .Weston, near Runw corn, England, assignor to Imperial Chemical Industries Limited, a corporation of Great Britain Application February 15, 1935, Serial No. 6,743 In Great Britain February 15, 1934 4 Claims. (o1. 87-43) the grease solvent and which still adhere to the metal article after the oil has been dissolved and removed by the solvent. It has been realized that 15 the non-removal of these insoluble particles con-. stitutes a disadvantage and it is usually proposed to agitate the metal in contact with a volume of liquid s'olventto efiect the mechanical removal of the particles. For the same purpose it has 20 been proposed to pass materials continuously through a spray of solvent. In many cases it is not possible to apply either of these methods, either because 'of the construction of the article to be treated or because there is an insufiicient 25 volume of work to enable a continuous process to be operated.

A well-known type of apparatus for degreasing comprises a tank fitted with condensing surfaces round the walls in the upper part, to prevent es- 30 cape of solvent vapor, and provided with means for vaporizing solvent, usually from a sump in the lower part of the tank, the sump being heated in any desired manner, such as a gas burner, steam coils, or an electrical heater.

According to the present invention I carry out the vapor and liquid treatment in the same apparatus and preferably at the same time by providing below the cooling coils in the upper part of such a degreasing tank, means for subjecting the 40 materials to be treated to streams of grease solvent delivered at high velocity from a series of jets. These jets are conveniently carried by a pipe or pipes situated close to a wall of the degreasing tank, and preferably the jets are ar- 5 ranged to traverse an arc of about 90. To enable this to be done the carrying pipe or pipes may be passed through the wall of the tank through a suitably packed joint and the movement actuated from outside the tank by a han- 50 dle, or by the driving mechanism of the pump to be subsequently described; Alt ernatively, with a number of series of. jetsthe carrying pipes are mounted completely within the tank in order to have a reduced number of feed pipes. passing 55 through the walls. Preferably at least two series pipes. can be incorporated in the suction pipe of the of jets are provided carried by pipes on opposite walls of the tank. When more than two series of jets are used they are spaced at regular lnter- I vals round the walls of the tanks. By this means the articles being degreased may be subjected si- 5 multaneously on all sides to the action of the jets and all parts treated at the same time. The solvent may be supplied to the jets by a small pump which draws its supply of solvent from a storage tank preferably provided with cooling means and situated close to the base of the degreasing tank. In order to maintain a supply of solvent in the storage tank, a sloping floor may be placed inside the degreasing tank underneath the articles being degreased to collect the used 5 solvent, which is then returned to the storage tank by pipes from the lowest part of the sloping floor. In this way a powerful and copious spray may be maintained with only a limited amount of solvent. The spraying is preferably performed while the vapor degreasing is proceeding, but it is most satisfactory to complete the operation with vapor degreasing alone since the liquid solvent becomes contaminated with grease after a time. This is not a serious objection provided that the amount of grease is not large, since the purpose of those jets of liquids is mainly the mechanical removal of grit and similar solid matter. The articles being treated may be suspended by suitable means inside the tank or may be carried on a perforated plate which, is arranged above the sloping floor. Preferably the perforated plate also carries a straining device to retain the solid impurities washed down by the solvent. By this means it is possible to avoid blockages in the Alternatively, a strainer of. known form pump. V

Thesupply of solvent in the sump in the bot-- tom of the degreasing tank may be maintained 40 by condensation from the coils in the upper part of the tank, but preferably I so arrange the plant that baflles or collecting gutters'deliver all the solvent condensed inside the degreasing tank,

together with the solvent used for spraying,

through the. strainer to the sloping floor feeding the storage tank, and then provide for an overflow from the storage tank to feed the sump in the base of the degreasing tank.

In treating the goods by means the lets it 5 will be obvious that considerable agitation of the air and vapor will take place inside th -degreasing tank, with consequent risk of the escape of solvent-laden air to the atmosphere. .The cover which isnormally used for preventing the escape of vapor while the plant is standing idle, may be used to prevent its escape during working. Preferably, however, I provide inside the tank a second lid which is situated between the spraying device and the cooling coils in the upper part of the tank. By placing the second lid in this position I am able .to ensure that substantially all the solvent splashed on the lid during the operation of the jets will subsequently be recovoered as condensate from the coils when the hot solvent vapor has heated the inner lid suiflciently to vaporize the solvent thereon. This does not occur when the normal plant lid is used.

Figures 1-4 show diagrammatically one form of apparatus according to the invention.

1 Figure 1 shows the apparatus partlyin elevation and partly as a section on the line |l of Figure 2.

Figure 2 is a section on the line 2- -2 of Figure l.

Figure 3 is a plan showing a method 01 tmversing the jet pipes.

The tank I in which the articles are to be degreased, is divided from the sump It in which solvent, e. g. trichlorethylene, is vaporized by a 95 sloping floor it, and the

jet pipes

4, 4, 5, 5, by means of which the articles are to be sprayed, are situated one in each angle of the tank between the sloping floor I 8, and the cooling coils 2.. A

distillate trough 3 collects the condensed solvent falling from the coils 2, and the'trough is provided with a cock (not shown) to draw off the distilled solvent if required; normally, the

solventin the trQugh is allowed to overflow into the tank I.

v The, solvent in the sump I6 is vaporized by steam heating coils I! or equivalent means, and

the vapor of the solvent rises into the degreasing zone through two series of

ports

33, 33, in the sloping floor l8, disposed near the walls of the tank I along the line of greatest slope of the floor l8. Baflles 26, 26 prevent, grit-laden solvent from falling through the ports33 by diverting the liquid on to a plate 21 perforated to allow the liquid to fall through a strainer 28 on to the floor I8,

whence it is delivered by pipe l5 to the storage tank 22. Partitions 32 prevent the liquid solvent from flowing into the sump via the ports 33, and

thereby impeding the egress of solvent vapor. Similarly, plate 21 maybe provided with a rim.

The solvent is supplied to the jets by a pump l9 which pumps the solvent from tank 22 through pipes 20 and I4 to pipes l3, connecting each pair oi. jet pipes 4, 5. The junctions l2 between pipes I3 and jet pipes. 4, 5, are constructed so as to allow rotation of the'jet pipes without interfering with the supply of liquid solvent. 1 The sump I6 is supplied with liquid from .tank 22 by an overflow pipe 2 l which is .l-shaped, so that liquid solvent in the bend prevents access of vapor to the container 22. If desired,

\ extra means may be provided whereby liquid is delivered 'to the sump by pump l9 when the supply from the overflow pipe 2| is :insuflicient.

An air vent 36 allows vapor-laden air displaced from the container b'y in-flowing liquid to be transferred to the tank 2| below coils ,2, so that no escape of vapor into the atmosphere can Mei'm ror rotating the jet pipes about their axes through approximately .90" consist of a rod I, cpnnecting the

end plates

23, 23, of

jets

5, 5; this connectingrod is provided with a link 8 which engages with a pin son a disc ll rotated by a handle) outside otthe'tank'; the common axle .75 of the handle and the disc passes thrpugha solmotion of the

jet pipes

5, 5, is communicated to jet pipes 4, 4, by rods 6 connecting the

end plates

23, 25 of the corresponding jet pipes 4 '5. These pipes are.held in position by suitable brackets (not shown) fixed to the wall of the tank- I.

A flexible shutter 35 of steel or other suitable material impervious to the solvent, is provided which in its normal position hangs between the wall of the tank I and the jet pipes 4. Loss of solvent during the spraying operation can be prevented by drawing this shutter over rollers 31, along guides 30 into the position shown in the figure by wire ropes which are wound round drums 34 on an axle 38 rotated by the handle 3|. The edge of the shutter remote from the axle .38 is weighted to facilitate the return of the shutter to its vertical position as the handle I 0 is unwound. v

Although the above is the preferred form of my invention, many alterations are possible without departing from the spirit of the invention, the scope thereof being fixed solely by the appended claims. Thus, instead of rotating the pipes, the wide are over whichsolventis sprayed may be produced by having several series of holes in the same pipe; or the tank may be provided with an inner perforated wall, and thesolvent may be pumped into the space between the two walls.

the solvent which is forced through the Jets.

I claim: p

1. Apparatus for degreasing metals and other non-absorbent articles by -means of volatile grease solvents which comprisesan open top vessel adapted to receive the materials to be degreased, means for supplying, solvent vapor to said vessel to establish a vapor degreasing zone therein, condensing surfaces disposed near the top of said. zone adapted to. condense solvent vapots and to limit thereby the .upward extent of said zone, and spraying means for projecting a spray of liquid solvent on the articles to be degreased, said spraying means comprising a plurality of substantially vertical jet pipes rotatable on their longitudinal axis and peripherally disposed'within said vessel.

2. Apparatus for degreasing metals and other non-absorbent articles by means 91' volatile therein, condensing surfaces disposed near the top of said zone adapted to condense solvent vapors and tolimit thereby the upward extent of said'zone, spraying means for projecting a spray of liquid-solvent on the articles to be degreased, said spraying means comprising a plurality of substantially vertical jet pipes rotatableon their longitudinal axes and peripherally disposed within said-vessel, and actuating means operable from the exterior of the apparatus for simultane- -ouslyrotating said jet pipes.

3. Apparatus fordegreasing metals and other non-absorbent articles by means of volatile grease solvents which comprises an open-top vessei adapted to receive the materials to be degreased, means for supplying solvent vapor to said vessel to establish a'vapor des'reasing zone therein, condensing surfaces located near the top 'aosaoia I top of said zone adapted to condense solvent. va-

of said Zone adapted to condense solvent vapors and to limit thereby the upward extent of said zone, spraying means for projecting a spray of liquid solvent on the articles to be degreased, and a movable shutter situated between said spraying means and saidcondensing surfaces,

greased, means for supplying solvent vapor to said vessel to establish a vapor degreasing zone therein, condensing surfaces disposed near the pors'and to limit thereby the upward extent of said zone, spraying means for projecting a spray of liquid solvent on the articles to bedegreased,

said spraying means comprisingv a plurality of substantially vertical jet pipes rotatable on their longitudinal axes and peripherally disposed within said vessel, actuating means operable from the exterior of the apparatus for simultaneously rotating said jet pipes, and a movable shutter situated between said spraying means and said con;- densing surfaces, said shutter being adapted to be closed during-the degreasing operation.

ROBERT ANDERSON EASTWOOD. 15