US1898727A - Tube cleaner - Google Patents

Description

J. J. HOPPES TUBE CLEANER Feb. 21, 1933.

Filed Feb. 14, 1931 3' Sheets-Sheet 1 INVENTOR ATTO RN EYS 4 Fl I b v.1 I MU IW y Feb. .21, 1933. J, HQPPES 1,898,727

TUBE CLEANER Filed Feb. 14, 1931 3 Sheets-Sheet 2 INVENTOR ATTO RN EYS Patented Feb. 21, 1933 sures JOHN a-norrns, or srnme rrntnyonro TUBE CLEANER Application-filed February 14, 1931 Serial No.-515,808.

This invention relates'toimprovements in that class'of heat exchange devices in which a heated "fluid is passedthrough"afluid tight I casing, the heat of this fiuidbe'i'ngtransmittedto a second "fluid passing through tubes arranged in the path-of the heated fluid.

The-improved heat exchanger is particu larly adaptedfor use'in such industries-as laundries Where large amounts of heated Water unfit for further use are available, the heat of which'ma'y be transferred to a supply of clean water of lower temperatures with a consequent increase in 'op'eratingeconomy. Since this hot'waste'water carries a largenmount of foreign matter either in suspension or otherwise, the depositing thereof on the tubes loWe'rsthe' efiiciency of .the heat transmission, the deposit or sludge aeting'as an insulator. Heretofore, heat exchangers have beencleaned by removing portions of the casingand scrubbing'theinterior memberswith'brushes, or by attempting to wash away the'ac'cumulations bywater under pressure as froma hose, either method requiring that the device be placed out of commission for the time being. In the present invention, the cleaning operationmay be .carriedout at anytime desired without in 'terference with the normal functioning of the device'as a heat'reclaimer, and, being preferably. power-driven and automatically stopped,-the' labor cost is -greatly reduced.

The object of: the invention is. to provide means whereby the convenientand economical removal of sludge from the surfaces of clean fluid conduits or: tubes is carried out. In the accompanyingdrawings:

Fig. '1 is afront'elevation'of a heat exaway to shovv portions of the interior de-. tails.

1 Fig. '5 is an enlarged fragmentary elevation in perspective-showing a portion of the cleaning apparatus.

Fig. 6 is an enlarged fragmentaryvertical section on'the line 6-6 of-Fig. 1, showing a portion of the'cleaning device together with partial details of the tube and header construction.

Fig. 7 is an enlarged fragmentary longitudinal section on the line 77 of Fig. 4.

Fig. 8 is a fragmentary vertical section on the line 8-8 of Fig. 2.

Fig. 9 is an enlarged'partial elevation of the left hand end of the device, aportion of theview being a vertical section on the line 9--9 of- Fig. 1.

Fig. 10 is an enlarged fragmentary horizontal section on the line 10- 10. of Fig. 9. Fig. 11 is a vertical section through an assembly of some of the details.

Referring to the drawings,the casing. of the improved heat-exchanger isessentially a fluid-tight sheet-metal box, admission and discharge openings for the fluid giving up its heat, hich willherezifter be termed the hot or Waste Water, being in the nature of long, rectangular openings in the lowermost 7 portions of the end Walls. 1 represe-nts'the' upper sheet, 2 the bottom or floor member, 3 the rear, and at the front Wall. The waste water enters at6 and flows into'a preliminary, hopper-shaped settling chamber 7 wherev aportion of thesludge is deposited. This "cham'berfis formed-by an outer wall 8 extending upwardly from the extension 2' of the'floor sheet-2 to apoint above the level of the'upp'er casing sheet 1. I

The s ettlingchamber'7 is closed at its upper end'bya horizontal sheet 9-secured to the upperedges of the Wall 8 and to. a Wall memberlO vvhich in turn is secured to the righthand edge of the upper-sheet 1. The chamber has a sloping bottom 11 for the greater portion ofits' extent'for thepurpose offacilitat ing the deposit of vany sludge, the slope causing the sludge to gravitate to" the bottom 7 of'the'chamber from where it may be drained oif'at intervals throughthe drain-pipe 12.

..will appear at a later point.

The flow of hot water is turned downwardly on entering the settling chamber as shown by the arrows in Fig. 2, then upwardly. there being a vertical bafile member 13 longitudinally disposed in the chamber 7 there being a horizontal wall 13 which closes the space in the settling chamber above the inlet on the outer side of the baflie so that all water must pass beneath the battle in proximity to the inclined bottom 11. The end wall 5 of the casing forms one side of the chamber and extends upwardly to a point not less in height than the level of the upper casing member 1 and provides an opening 1a between the upper edge 5 of the wall member 5 and the chamber top member 9. This opening l i communicates with a vertical channel 15 formed between the end wall 5 and a partition member 16 placed in parallel relation there with and preferably extending the full width of the casing from front to rear, the front and rear walls of the channel 15 being extensions of the wall members 4 and 3, respectively. The hot water then flows downwardly through this narrow vertical channel 15 and into the casing through an opening 17 below the bafiie member 16, the battle 16 extending to within a short distance of the floor 2 of the casing.

The accompanying drawings show a casing whose interior is divided into two compartments by a single vertical, transversely disposed partition member 18 in parallel relation with the end walls and joined at its upper front and rear edges preferably by fluid-tight joints to the upper member and front and rear walls 4 and 3. This partition also extends to within a short distance of the floor 2, providing a horizontal opening 19 similar to the opening 17. The two compartmentsmentioned are designated C and C,

and are termed heat-exchangingchambers,

since in each chamber are inserted interconnected, unitary structures comprising tubes. headers and other associated details in which the fluid to be heated is passed." In the present specification the fluid. being heated is termed simply the clean water, while the de;

scription of the conduits carrying the same the chamber C is undulatory, the Water arming immediately on entering the chamber through the opening 17 by virtue of its heat. As it ascends, heat is lost and the velocity of this upward current is reduced, and on impinging on the'under surface of the upper sheet 1 is diverted to the left, flowing downwardly through the left side of the chamber 0 along the partition 18 towards the opening 19. The opening 19 is, of course, the inlet opening tov the chamber C, wherein a repetition of the flow just'described occurs.

The outlet for the chamber C is also adjacent the floor member 2 in the same manner as the openings 17 and 19 are arranged and is designated as at 20, Fig. 1. The flow after passing through this opening 20 is upwardly through a narrow vertical passage 21 formed by the parallel position of a bafiie sheet 22 and the end wall 23 at the left extension of the casing. The passage 21 discharges into an enclosure comprising the walls 24, 25 and 26, F ig 7 in connection with suitable front and rear wall extensions forming a fluid-tight passage-way leading to the discharge connection 27, it being noted that the flow through the enclosure reaches an altitude greater than the level of the upper portions of the casing, as the edge 23 of the end wall 23 extends above the upper sheet 1, in the same manner as described in connection with the upper edge 5. The advantage gained-in causing the incoming and outgoing flows of hot water to be at greater elevations thanthe upper portions of the casing is that the casing at all times remains completely'filled with water whether in operation or not, therefore any sludge that may be deposited within the casing or pas sages leading to and from the same, or upon the clean Water conduit arrangements, remains in a more plastic condition, being prevented from drying and consequent hardening which would result in an expensive clean ing operation. This construction also permits the drainage of the settling chamber 7 without lowering the level of the water in the interior of the casing.

By causing the waste water to enter and leave at the lowermost portions of the casing the previously mentioned advantage is gained of allowing a. short-circuiting of any occasional quantities of colder waste water, the path of such being comparatively direct from the casinginlet 17 to the outlet 20, the water, by its greater density remaining near the floor. A further minor advantage is that, by the provision of'hand-hole openings normally covered by cover-plates such'as are indicated at 28, Fig. 2, and at 29, Fig. 4., access may be hadto the floor area of the casing forinspection or such cleaning. thereof as may be desired." The casing maybe drained by opening a valve (not shown) connected with a drain-pipe 30 preferably located near the Casing outlet 20. I

The improved heat-exchanger is designed I to provide that a modification of the effective counter-flow scheme is employed, the path of the flow of clean water receiving heat starting at the lower left extremity of the device and terminating at the lower right portion in proximity to the waste water inlet. It is clear from the description so far that the path followed by the waste water is a series of undulations moving from right to left, andthat a chamber suchas C encloses a single undulation consisting ofja descending and ascending column of water of substantially rectangular cross-sectional area.

The simplest counter-flow arrangement would be to cause the path ofthe clean water to closely conform to the undulatory path of the waste water in all respects, but I preferan ascending column, of waste water. The

exact relation of the paths one to another may be stated in other-words by explaining that a cross-section taken on a horizontal plane through either an ascending or descending column ofv waste water is substantially rectangular in form, the long dimension extending fromfront to rear, and that the path of the clean water within the casing is always parallel to the long dimension.

Such an arrangement has'an advantage in that an extended clean water path is provided in-a relatively small space. There is also an advantage that it is possible that a desired number of tubes and associated parts may be combined into a unitarystructure of which a plurality are employed, each of which may be inserted or withdrawn'into or from the Y casing independently of the others, all connecting mediums conveying fluids from one to another of the structures being made on the outside of the casing.

The clean water is conveyed throughout the casing interior in tubes 31 ofwhich a preferably equal number is associated in each unitary structure or bank, in the present case there being two banks for each single heat exchanging compartment such as C or C. The tubes are arranged in vertical and horizontal rows, asseen bestin Figs.:1 and 5, although it is clear that a staggered arrangement could be employed. Referring to the initial bank, employed in the left portion of the chamber C, the tubes are secured at their forward ends in a. flat plate-32 and at their farther ends in the raised-portion'33 of a hollow header 33 preferably by a rolling and calking process,:this operation at theirconnection with the header 33- being performed through openings in alignment with each tube,

The front wall 4 of the casing is provided with rectangular openings 4 through which the openings being closed by the plugs the unit is inserted into the casing. Rollers 33 are fitted to the bottom portions ofthe headers 33 whereby greater ease of assembly maybe secured. -The plate '32 is sufficiently large to act as a cover foran opening 4' and through the overlying portions of the plate 32 screws are insertedwhich thread into openings'in the front'wall 4, and also passing throughthe overlying-flange 34' of a dishshaped cover casting 34. The dished interior of the cover casting isdivided into compartments by horizontalbafiies 35 and 36 into the compartments 34 34 and 34, these baffles being of such height as to bear against the plate 32 and effectually prevent the passage of fluid from any compartment to another. In the rear header 33 an integral baffie 37 is 'emp'loyed,-which divides the interior of this header into two compartments 33 and 33. The alignment of the baffles 35 and 36 in the cover 34 in relation to the bafiie 37 in the header 33 is such that the compartment communicates with a plurality of tubes which discharge into'the lowermost portion of the compartment 33, while tubes leading from the uppermost portion of the compartment discharge into the lowermost partof the-compartment 34 The tubes in communication with the upper portion of the compartment 34 lead to the lower portion of the compartment 33 in the rear header,

and fromthe upper part of this latter compartment the tubes discharge into the compartment34 at the upper end portion of the cover 34.

Openings '38 and 39'are provided in the raised portion of the cover casting 34, the opening 38 being an inlet opening where the clean water makes its initial entrance into the conduit arrangen'ient, communicating directly with the compartment 34, while the opening 39 communicates with the compartment 34. It will then be seen that the clean water flowing into the compartment 34 travels rearwardly throughthe lower tubes into the compartment 33 and is then returned forwardly to the compartment 34 then again in a rearwardly direction into the lower part of the compartment 33, then forwardly into the compartment34 and outwardly through the opening 39. Alternate movements are thus made in a directiongenerallyiupward, and since the bank as just described occupies the left hand portion of the chamber C in which portion a descending column of'waste water is flowing, a heat transfer in accordance with the preferred modified form of counterfiow takes place.

The water issuing from the upper compartment 34 passesthrough the opening 39 and through a hollow duct 40' into theupper compartment 34 of the cover 34 of the succeeding-bank of tubes, which bank is placed in the rightside of the chamber C. By admitting the fluid to this compartment, which is in fact the compartment 34 of the second bank, the water flows towards the rearward header and thereafter in a generally downward direction to the opening 38 in this bank, and is-then conveyed by the duct 41 to the succeeding banks. The generally downward movement of the clean water in this bank is also in, a direction counterwise to that of the waste water, which in this half of the chamberis upwardly. The fiow of clean water continues as described through all of the plurality of banks of tubes, finally issuing at the outlet opening 38 in the bank nearest the waste water inlet 17.

A plurality of banks such as have just been described are employed in the heat exchanger. The present drawings show four only, these being placed two each in a single compartment such as C or C, therefore there are two forward and two rearward movements of the clean water for each ascending or descending columns of waste wa ter, or sixteen to and fro movements for two undulations in the heat exchanger illustrated in the drawings. This provides perhaps the shortest path practical for either of the fluids for an exchange of heat of any appreciable economy; certain circumstances may indicate that a more complete abstraction of the available heat units in the waste water may be made by providing a longer path for the fluids. The design of the present exchanger lends itself to such extensions as it isonly necessary to employ additional chambers and banks of clean water conduits, using the casing and constructions as described, it being understood that a partition 18 is employed. between adjacent chambers.

As has been previously mentioned, the deposit of sludge on the outer surfaces of the tubes 31 interferes with the effective transfer of heat to the cooler fluid, therefore to maintain the efficiency of the device at an economical rate, frequent removal of the greater portion of the sludge is necessary. To this end a mechanism, preferably operated by an electric motor, is employed for each bank of tubes, and all such mechanisms being preferably operated simultaneously.

T -e essential detail of the cleaning mechanism is a fiat, perforated metallic plate 42 in which are openings 42 slightly larger in diameter than the tubes 31. These openings are regularly spaced to the same dimensions as the spacing of the tubes, so that the plate may be placed on the tubes in an interposed relation between the forward tube plate 32 and rear header 33, this being done at the time of the assembly of a bank. It will then be clear that a movement of the plate 42 from one extremity to another of the exposed tube surface will remove by an agitating action the greater portion of any matter adhering thereto. The movement of the plate in operation is an alternate to and fro movement, produced by rotating a pair of screw-threaded rods simultaneously in either direction. The screw-threaded rods are indicated at 43 and 44, and are alike, and as seen best in Fig. 5, are arranged in parallel relation to the tubes, one above and below the bank thereof. The rods are rotatably mounted at the rear ends in the lugs 45 and 46, projecting upwardly and downwardly, respectively from the central portions of the upper and lower extremities of the header 33, Fig. 4, and at their forward ends in a bearing comprising a partial bearing in the inner surface of the cover 34 and a more extensive bearing in a gland 48 concentrically positioned in the outor extremity of a boss 49 projecting from the cover 34 at the upper and lower portions thereof. Those portions of the screw rods 43 and 44 that are rotatably mounted in the bearings just described are in the nature of reducer'l-diameter extended portions indicated at 43 and 44, 43" and 44", respectively referring to the forward and rearward portions of the rods, one only of the forward bearing arrangements being shown in the drawings, i. e., a forward upper bearing as seen in detail in Fig. 6. The gland also acts to compress the packing material 50 placed around the portions 43 and 44 of the screw rods, being forced in place by a plate 48' in order to prevent any leakage of fluid through the forward bearings described. The plates 42 are provided at their upper and lower extremities with re-enforcing casting members 51 and 52 having in their central portions bosses 53 which are interiorly threaded to receive the screws 43 and 44. The screws are rotated in the present instance by a reversible electric motor 55 mounted in any convenient location on the forward side of the casing. The motor is connected by a speed reducing mechanism shown conventionally at 56 to each of the plurality of screws 43 and 44 by sprockets and a chain. The sprockets are shown at 57 and are fixed in alignment on the extended reduced diameter portions 43 and 44 previously mentioned and over all sprockets the chain 58 is passed. At suitable points idler sprockets such as are indicated at 59 are employed,

whose function is merely to cause the chain 58 to more closely hug the sprockets and thereby prevent climbing of the chain upon the sprocket teeth. The speed reducing mechanism is preferably connected to a further extended portion of one of the screws 43, the extended portion 43 passing through and keyed to the master gear (not shown) of the speed reducing device 56. Y

The motor is started and stopped by closing and opening the'double pole reversing switch indicated conventionally at 61. In the present instance, the motor is started manually by throwing the switch to a closed circuit position, and since the normal position of the scraper plate 42 when not in operation is at one end of the exposed tube surface a simple switch operating device permits the starting of the motor only in the direction it may run to cause movement of the plate towards the opposite end, thereby preventing damage to the parts. This mech anism is also employed to stop the motor automatically and therewith the movement of the plate at the completion of a traverse of the plate along the tubes.

uses-#27 At convenient location in proximity to an agitator plate 42, preferably at the upper end of the plate nearest the switch location, is arranged a rod 62 in parallel relation to the travel of the plate 42. This rod extends rearwa-rdly through the rear wall of the casing to the outside, and has a slidable bearing in a stufling box arrangement comprising a bored body portion 63 and the gland 64, while the forward end rests in and has a slidable bearing in a thimble 65 inset in an opening in the cover casting 34 leakage being thus prevented at either polnt mentioned. On the rod 62 at suitable positions within the casing are check nuts 66 which make contact with a lug 67 projecting from the upper surface of the plate casting 51 through which lug the rod 62 is passed.

On the outer rearward extension 62 of the rod 62, Fig. 9, isa pair of check nuts 68 and 69 spaced apart as shown, between which is interposed the upwardly disposed forked end of a lever 7 0 secured to a horizontal rock shaft 71 held in suitable bearings 71'. The shaft 71 terminates at a suitable point above the switch 61 and on the end thereof is a lever 72 which is substantially horizontally disposed. To the free end of the lever 72 a downwardly hanging rod 73 is pivotally connected, while the lower end of this rod is pivotally connected with a crank-pin 74 projecting eccentrically from a disk 75 loosely rotatably mounted on a stud 76. The stud 76 is secured in a bracket 78, in concentric alignment with the center of rotation of the switch arm 77, the bracket 78 being the means of support for the switch box and being suitably attached to a convenient portion of the heat exchanger casing. V

Projecting from the disk 75 in proper angular displacement as regards the crank-pin 74 (in the present case, on the side opposite the pin 74) are pins 79 which, on partial rotation of the disk in either direction alternately make contact with the switch-arm 77 to cause the switch to be thrown to the open or neutral position as shown in full lines in Figs. 4 and 9.

This movement is the only function of the pins 79 in the present case, although it will be clear that with a suitable switch and link age the plates 42 may be given a continuously reciprocating movement as long as electric current is supplied to the motor. With the device as shown, one of the pins 7 9 (see Figs. 4 and 9) is always in the position it has assumed on stoppage of the motor, and therefore it is not possible to throw the switch manually or otherwise to an on-position where damage to the mechanism may be caused. The position of the switch arm 77 as seen in dotted lines in these figures is seen to be the only permissible position in which it may be placed.

The operation of the heat exchanger as a unit issimply to allow the warm waste'water to-pass through the casing-in the manner described, the clean water absorbing the greater percentage of the heat thereof through the walls ofthe tubes 31; As the sludge deposit: develops on the tubes, the operator places-the switch arm in the closed circuit position allowable by the linkage connection, whereupon all the plates 42' are moved simultaneously in the proper direc tion, and on approaching the endof the stroke the movementof the rod 62' by the plate with which it is. connected throws the switch to the neutral position through the linkage: de scribed.

The 'weigh-t'of each plate 42 is imposed on itsscrews 43 and 44inorder to prevent wear of the tube surfaces. Due to the fact that the openings in each plate 42 are larger than the tubes and the plates are supported by the screws, the. sludge will be removed from the tubes by agitation ofthe liquid set up by the plates moving therethrough as distin; guished from a scraping action, this arrange ment obviating any wear upon theouter surfaces of'thetubes such as would be occasioned by a. scraping action with the scrapers in direct contact with the tubes' The. sludge thus removed 'issetfree and is carried in the currentof the, flowing waste water and since a large percentage of the sludge is of the same approximate specific gravity it: is readily carried out through-the vertical'casing discharge passage21, which is somewhat. restricted to increase momen tarily the velocity of the flow at thispoinh In the use of the apparatusto heatorcool oil or any liquid with high viscosity or wherever desired the agitators can'be operated continuously to keep the tubes free of viscous substances or sludge and thusincrease the heattransfer through the tubes by keeping them free from such substances; i

I have filed a; divisional application on January 25, 1933, and bearing Serial Nume ber.653,461 for thesubject matter of the heat exchange device described in this application.

Having thus described my invention, I claim:

1. In a cleaning mechanism for the exterior of tubes arranged in a bank, a member arranged transversely of the series of tubes and having surfaces surrounding the exterior of the tubes, means for moving said member longitudinally of the tubes, said means including an electric motor, and means for automatically stopping the motor at a predetermined point in the movement of said member. I

2. In a cleaning mechanism for the exte rior. of tubes arranged in a bank, a member 6 arranged transversely of the series of tubes ofthe length of said tubes upon which said member is threaded, means for holding said member from turning, means for revolving said screw, said latter means including an electric motor, and means for automatically stoppingthe motor atva predetermined point in the movement of said member.

3. In a cleaning mechanism for the exterior of tubes arranged in a bank, a plate-like member having a plurality of perforations, one for each tube, the walls of said perforations having a loose fit with the respective tubes to permit the member to move longitudinally thereof, a pair of screws extending parallel with the tubes upon which said member is threaded, and means for rotating said screws simultaneously at the same speed to cause said member to travel in an endwise direction with relation to said tubes.

4. In a cleaning mechanism for the exterior of tubes arranged in a bank, a member having surfaces surrounding each tube and movable longitudinally of the tubes, means for moving said member including a reversible electric motor, a switch for controlling the circuit of said motor having a movable member with an off-position and an onposition on each side of the off-position, means operated by said cleaning mechanism for moving the movable member of said switch to the off-position at a predetermined point in the movement thereof, and means for automatically locking said movable member against movement to one of said oil-positions when thrown to neutral position.

5. Ina cleaning mechanism for the exterior of tubes arranged in a bank, a member arranged transversely of the series of tubes and having surfaces surrounding the exte- .r1or of the tubes, power-operated means for moving said member longitudinally of the tubes and means for automatically stopping the power-operated means at a predetermined point in the movement of said member.

In testimony whereof, I have hereunto set my hand this 7th dayof February, 1931.

JOHN J. HOPPES.

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