NZ202160A

NZ202160A - Centrifugal hydroextractor:out-of-balance sensing between casing and suspension post

Info

Publication number: NZ202160A
Application number: NZ202160A
Authority: NZ
Inventors: A D Thomas
Original assignee: Macewans Machinery Ltd
Priority date: 1982-10-13
Filing date: 1982-10-13
Publication date: 1986-11-12
Also published as: AU1973883A; AU562856B2; GB8326607D0; GB2128723A; GB2128723B

Description

<div class="application article clearfix" id="description"> m ' / / ' / 202160 PATENTS FORM NO. PATENTS ACT 1953 COMPLETE SPECIFICATION No. 202160 Date: 13 October 19 8 2 Complete After Provisional m CUrA BSoC \s/»c)©3 IMPROVEMENTS IN AND RELATING TO HYDRO-EXTRACTORS WE, MACEWANS MACHINERY LIMITED of 34 Hutt Road, Kaiwharawhara, Wellington, New Zealand, a New Zealand company, hereby declare the invention, for which we pray that a Patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: •feilococd bq page I a. 202 aSO - 1A- The present invention relates to improvements in and relating to hydro-extractors. Such machines, also known as whizzers generally comprise a perforated cylinder into which material to be dried is inserted and whereby upon rotation of the cylinder centrifugal force will remove the liquid therefrom. Various advantages have been found in hydro-extractors available to the present time and it is thus an object of the present invention to provide a hydro-extractor which obviates at least certain of these disadvantages and provide a liquid extraction from materials placed therein in a speedy, efficient and reliable manner. Further objects of the invention will become apparent from the following description. According to one aspect of the present invention there is thus provided a hydro-extractor comprising: (a) an outer casing mounted on a suspension means; (b) a perforate, substantially hollow, basket rotatably mounted within said casing which receives material from which liquid is to be extracted by centrifugal action and allows free discharge of liquid therethrough as said basket rotates; (c) a substantially vertical drive shaft connected with, to rotate, said basket; (d) detecting means to detect an excessive radial movement of said casing during rotation of said basket, said detecting means extending between said outer casing and said suspension means; (e) drive means coupled with, to drive, said drive shaft; 202160 2 (f) drive control means operable when said excessive radial movement is detected to terminate the drive to said drive shaft; (g) braking means operable on said drive shaft to control the rotation of said basket; and (h) a cover means provided to close an open upper end of said casing when a liquid extraction operation is being effected. Further aspects of this invention which should be considered in all its novel aspects will become apparent from the following description given by way of example of one possible embodiment thereof and in which reference is made to the accompanying drawings wherein; FIGURES 1 & 2 : show plan and side views of a hydro-extractor according to one embodiment of the invention and particularly the foundations therefor; FIGURES 3 & 3a show more detailed, part cross-sectioned, views of the hydro-extractor of the preceding figures; f 16 APR 1986 / ^ • ; / •. •• i . - . - - .- 202 f6P -3- FIGURES 4 & 5 10 15 20 FIGURE 6 FIGURE 7 FIGURE 8 FIGURES 9 & 10 : FIGURE 11 FIGURE 12 25 show cross-sectional and end-detail views of the basket assembly for use in the hydro-extractor of the preceding figures; shows a cross-sectional view of a center-piece assembly for use with the basket of Figures 4 and 5; shows a cross-sectional view of the suspension assembly for use in the hydro-extractor of the preceding figures; shows schematically an hydraulic circuit suitable for use with the hydro-extractor of the preceding figures; show plan and side cross-sectional views of a braking assembly suitable for use with the hydro—extractor of the preceding figures; shows schematically an hydraulic circuit for two hydro-extractors; shows schematically an hydraulic circuit for a single 202I&0 -4- hydro-extractor; FIGURE 13 : shows schematically an out-of-balance switch assembly suitable for use with the ■'a 5 hydro-extractor of the preceding figures. The present invention can be broadly said to relate to a hydro-extractor which, whilst it has been J specifically developed for the centrifugal de-watering 10 of lamb and sheep pelts after a washing process, could be used for the removal of any liquid from any of a wide variety of materials such as animal skins, wool, textile materials and granular materials for example. In a preferred embodiment of the invention the 15 hydro-extractor will be hydraulically driven from an external drive control assembly and will be fitted with suitable interlocks and other safety features whereby the acceleration, running and braking .) sequences, will be automatically controlled. 20 The hydro-extractor will generally comprise an outer casing which will be freely suspended suitably from a plurality, three or more, of suspension bolts v depending from pillar housings. These can have hemispherical bearings whereby the casing will be 25 permitted free but limited movement radially in all -5- 202 directions. Within the casing will be mounted a suitable perforate basket rotatably mounted therewithin on a substantially vertical drive shaft. The drive shaft is suitably mounted within a column having bearings whereby journal and thrust loads from the rotating basket and contents thereof can be absorbed. The drive shaft will suitably be directly coupled to an hydraulic motor whereby the basket can be rotated at a controlled rate of acceleration up to the desired operating speed. The casing will have a substantially open upper end enabling access to the basket therewithin for insertion and removal of the material to be de-watered but a hinged and counterbalanced safety cover will suitably be provided for the casing which when in its lowered position will close this opening. A suitable switching means will suitably be provided whereby the basket will not be able to be rotated at other than a slow speed of rotation unless the cover is in its closed position. Also, a centrifugal latch means may suitably be provided which can engage with the cover and prevent it being opened while the basket is rotating at other than its slow rotation speed. In addition an / 202140 -6- hydraulic latch cylinder and/or mechanical latch means may suitably be provided to engage the cover. The cover will suitably have a peripheral flexible member on its underside providing a seal 5 between it and the casing. It has been found experimentally that when the basket is rotating a reduced pressure is created within the casing maintained by the aforementioned seal. The resultant downward air pressure on the cover is such that the 10 cover cannot be manually opened either by lifting from the outer edge or by bearing down on the counter-weight arm. This therefore provides a safety feature additional to the aforesaid centrifugal latch. As aforementioned the casing will suitably have a 15 free but limited movement radially in all directions. However to prevent damage to the hydro-extractor if the casing movement became too great, an out-of-balance switching means may be provided on one of the aforesaid columns which will be contacted and 20 operated by the casing if its movement exceeds a predetermined value so that the normal stop and braking sequence will be actuated to bring the basket to rest. A timing means will suitably be provided whereby 25 an automatic braking system will bring the basket to / #» 202 -7- rest at the end of a predetermined time of rotation of the basket at its full speed. The hydraulic drive motor, which as aforementioned may suitably be directly coupled to the 5 drive shaft, may be supplied with hydrualic oil at controlled pressure and volume from an external, if necessary remotely mounted, hydraulic power pack. The power pack may comprise a motor driven hydraulic pump with suitable control valves and the like to allow 10 automatic operation and control of the hydro-extractor drive. Suitable filters, oil cooler and oil reservoir will be provided in known manner. The controls for the hydro extractor may be contained in one or more separate housings with a main 15 control panel housing the starter for the pump motor together with the relays, solenoid operated control valves, timers etc. which control the operating and braking sequences together with the necessary interlocks whilst operator controls located near the 20 machine would include a control station having suitable push buttons and indicator lights. In operating the hydro-extractor the "start" button on the main control panel may be operated which will start the electric motor for the hydraulic pump. 25 The cover will then be raised and the operator would 2021 press the "brake release" button at the control station and then the "slow rotate" button so that the basket can be slowly rotated and an even loading of the basket can be facilitated. 5 Once loaded the cover can be lowered which will actuate the safety switch and the operator can then press the "fast rotate button" which will allow the basket to accelerate up to its running speed. During acceleration the centrifugal or other latch on the 10 casing when provided will engage with the cover to prevent its being opened while the basket is rotating at speed. At the end of a predetermined running period the timer will automatically initiate a 2-stage braking 15 sequence. In the first stage the drive motor is caused to act as a pump with a restricted discharge so it acts as a brake and decelerates the rotation of the basket. Finally the disc brake system is energised and brings the basket to rest. 20 Once the basket is at rest the centrifugal latch, and the hydraulic latch cylinder if fitted, will disengage and the cover can be raised and the basket unloaded. To facilitate unloading the operator can press the "brake release" button which allows the 25 basket to be rotated by hand or alternatively the 2CZ1 GO -9- V "slow rotate" button can be operated. If required the hydraulic power pack can, with the addition of suitable interlocks and controls, be arranged to drive a pair of hydro-extractors of the 5 present invention so that one can be unloaded and loaded while the other is running. The casing would be provided with a suitable discharge outlet whereby liquid removed from the basket contents through the perforations of the basket 10 and collected in the casing can be discharged, suitably by gravity. Counterweights may be fitted to the lower part of the casing or the bottom of the casing may suitably be filled with concrete or similar dense material so as 15 to increase its mass which will enable a greater out-of-balance in the load to be tolerated before the radial movement of the casing becomes too severe and the out-of-balance switch mentioned above operates to stop the basket. 20 Reference will now be made to the accompanying drawings wherein one possible embodiment of the invention and suitable ancillary and associated equipment therefor are illustrated. Thus, referring firstly to Figures 1 and 2, a 25 hydro-extractor 1 according to one embodiment of the -10- 2021 invention includes a casing 3 suspended on a triangular framework of columns 4 mounted on a baseplate 5 which in turn is secured by means of holding-down bolts 5a with a concrete foundation 2. The casing 3 has an open upper end which can be closed by a hinged and counterbalanced lid or safety cover 6 and which can be raised in a direction indicated by arrow A when unloading or loading the contents into a basket 7, see Figure 3, is required. Referring to Figures 3 and 3a of the accompanying drawings the lid 6 is shown with a counterweight 8 and hinge assembly 9 enabling it to close-off an open end 10 of the casing 3. A switch 38 can be controlled by the lid 6 and in turn control circuitry associated with the drive to the basket 7 so that unless the lid 6 is closed the basket 7 cannot run at speed. A hollow perforate basket 7 is shown rotatably mounted within the casing 3, having a central mounting portion 11 whereby the basket 7 can be connected with a vertical drive shaft 12. A resilient seal 6a is provided under the safety cover 6 so that reduced pressure in the casing 3 created by rotation of the basket 7 can be maintained. This reduced pressure will act against the manual opening of the cover when the basket is at speed. 202160 -ii- A latch assembly 37, for example of the centrifugal type as shown can be provided to hold the cover 6 closed while the basket 7 is rotating at speed. The latch assembly 37, see Figures 3 and 6, has a pair of 5 oppositely facing hooked latch members 54 pivoted by pivot bolts 153 extending between pairs of upstanding supports 152 provided on either side of a mounting plate 50 which has an aperture 151 to enable it to fit over the threaded drive shaft end 12a. The members 54 10 thrown outwardly by centrifugal force when the basket 7 rotates to engage an angle retaining ring 55 bolted under the cover 6. Alternatively, or additionally, a hydraulically operated lid latch 46 and/or a mechanical latch 36 could be used. 15 As shown in Figures 4 and 5 the basket 7 can include a peripheral lip 13 with top and bottom flange members 14 being shown provided and riveted or otherwise secured to the top, bottom and side wall members forming the basket. The side wall member at 20 least is perforated to enable the egress therefrom of liquid from the contents of the basket by centrifugal action as the basket is rotated at high speed. As will be particularly seen from reference to Figure 6 the centerpiece assembly referenced genez&3p3yN p 25 by arrow 15 provides a rotatable mounting for tji^ drive shaft 12 on which the basket 7 is itself !r 16 APR 19862; / 2021 -12- mounted. The assembly 15 is shown provided with a flange portion 16 which can be bolted or otherwise secured to the casing through bolt holes 17 and a central boss portion 18 including roller bearings 19 5 which are able to accommodate journal and thrust loads from the drive shaft 12 and basket 7 mounted thereon. As shown, the top of the drive shaft 12 is tapered so as to accept the taper on the central portion 11 of the basket 7, a threaded end 12a of the 10 shaft 12 being provided to accept a nut assembly 24 after the basket central portion 11 and mounting plate 50 has been placed thereover. The casing 3 is supported as aforementioned by a plurality of columns or pedestals 4. 15 As will be seen particularly from Figures 3 and 7 the casing 3 has outwardly directed support bars or shafts 23 which are engaged by a respective suspension bolt 22 at the top end of which is provided a hemispherical bearing 21 permitting the radial 20 movement of the casing 3 as the basket 7 is rotated. This radial movement of the casing 3 is kept within predetermined limits by an out-of-balance switch 20 hereinafter described in greater detail in relation to Figure 13. 25 Referring now to Figure 8 of the accompanying drawings the basket 7 is shown schematically with its ■ .. . • ' ; ■ / . / , . ■ .\ r i .. - ■ - / 2021 &e> -13- drive shaft 12 directly coupled with an hydraulic motor 25, disc brakes 34 hereinafter described in greater detail with reference to Figures 9 and 10 being shown provided for the shaft 12. 5 A suitable self contained external power pack 27 is shown provided connected with the brakes 34 and hydraulic motor 25 so that the rotation of the hydro-basket can be controlled. The hydraulic system enables the baskets to be driven at two speeds, 10 controlled by the aforementioned "slow rotate" and "fast rotate" control buttons (not shown). The fast speed will not be capable of selection however until the safety switch 38 is operated indicating the cover 6 is lowered. The power pack 27 which may be of any 15 suitable type may suitably include an oil cooler 28, an oil reservoir 29, a pump 30, suction filter 31 and gate valve 32. The hydraulic system allows for braking of the basket rotation in 2 stages. When the "stop" button is operated delivery of oil from the 20 pump 41 is stopped and oil still circulating through the motor 25 is relieved accross the crossflow valve 44 under pressure thus giving the motor 25 a braking action. After a suitable and adjustable time delay, during which the basket 7 is decelerated, the brake 25 solenoid 43 is energised and the disc brakes 34 are applied thus bringing the basket to rest. 202160 -14- The disc brake assembly referenced generally by arrow 26 is shown in greater detail in Figures 9 and 10. The bottom of the drive shaft 12 extending through the boss 18 and roller bearing 19 is shown provided with an outwardly extending disc plate 33 which as the shaft 12 rotates passes between brake calipers 34, a direct coupling being provided from the shaft 12 to hydraulic motor 25. In Figure 9 which is a cross sectional view taken on arrows X-X of Figure 10 the calipers 34 are shown positioned on either side of the disc plate 33 with the hydraulic coupling to the calipers 34 being shown in outline. This coupling is itself coupled to a suitable solenoid or other control valve whereby at the end of a predetermined time, the operation of the "stop"button, or the operation of the out-of-balance switch, the brakes will be applied so that the rotation of the basket 7 is stopped. Referring briefly to Figures 11 and 12, these respectively show hydraulic circuits for a dual and a single machine drive. Thus in Figure 11 the hydraulic lines 40 will be connected with the other hydro-extractor whilst the J/R o; circuit shown includes pump 41, hydraulic motor 2s>v solenoid valves 43, cross-flow valves 44, brake ^ 16APR1986 -15- 202 cylinders 34 and lid latch cylinder 46 (the latter being an optional feature which may preferably be omitted). The pump 41 may suitably be driven by an electric motor 47. Additional hydro-extractors could however be connected into the circuit if required. In the hydraulic circuit shown in Figure 12 for use with a single machine the same reference numerals have been used where appropriate. A pressure switch 48 is shown included which may however be omitted, drain lines 49 being shown in outline in both figures connected with reservoir 29. Turning now to Figure 13, the casing 3 is shown provided with an out-of-balance switch 20 which comprises a bracket 51 provided on the casing 3 with an aperture therein accommodating a downwardly depending member 52 connected with a suitable switching means 53. Thus, if the radial movement of the casing 3 due to out-of-balance of the basket during rotation is above a predetermined limit, determined by the relative shape and size of the aperture in bracket 51 and member 52 respectively, the corresponding movement of the bracket 51 will be such as to engage and move the member 52 to a sufficient degree to operate the switching means 53 resulting in the operation of the "stop" control and thus bringing the basket 7 to rest. / 20ZI6& -16- As an additional safety feature, and as mentioned above, it is envisaged that a mechanical latch 36 may be provided connecting the lid 6 with the casing 3. Preferably this would be spring loaded so that it 5 automatically latches when the lid 3 is closed and is manually released when the lid 3 is to be opened. This would be an alternative to the previously mentioned hydraulically operated lid latch cylinder 46. Where in the aforegoing description reference has 10 been made to specific components or integers of the invention having known equivalents then such equivalents are herein incorporated as if individually set forth Although this invention has been described by way 15 of example and with reference to one possible embodiment thereof, improvements or modifications may be made thereto without departing from the scope of the invention as defined in the appended claims. </div>

Claims

- 17 - 202169 WHAT WE CLAIM IS:

1. A hydro-extractor comprising: (a) an outer casing mounted on a suspension means; (b) a perforate, substantially hollow, basket rotatably mounted within said casing which receives material from which liquid is to be extracted by centrifugal action and allows free discharge of liquid therethrough as said basket rotates; (c) a substantially vertical drive shaft connected with, to rotate, said basket; (d) detecting means to detect an excessive radial movement of said casing during rotation of said basket, said detecting means extending between said outer casing and said suspension means; (e) drive means coupled with, to drive, said drive shaft; (f) drive control means operable when said excessive radial movement is detected to terminate the drive to said drive shaft; (g) braking means operable on said drive shaft to control the rotation of said basket; and (h) a cover means provided to close an open upper end of said casing when a liquid extraction operation is being effected. i-aTEM U»' 1 2 2SEP 1986 202160 -18-

2. A hydro-extractor as claimed in Claim 1 wherein said suspension means comprises: (a) a plurality of columns spaced apart about said outer casing; (b) a bearing means provided at an upper end of each of said columns; (c) a suspension member located within said bearing means and extending downwardly therefrom; (d) a support bar connected at one end with said outer casing and at an opposite end connected with a lower end of said suspension member.

3. A hydro-extractor as claimed in claim 2 wherein said detecting means comprises a switching means having a bracket means connected with said outer casing and extending outwardly therefrom, said bracket means including an aperture therein, said drive control means including a switch having an operating member extending into said aperture and adapted to be operated by the movement of said bracket when said excessive radial movement is detected.

4. A hydro-extractor as claimed in any one of the preceding claims wherein a central portion of said basket is adapted to accommodate therein an upper ,/ 202160 19 portion of said drive shaft, a lower portion of said drive shaft having a disc plate extending outwardly therefrom and rotatable between, and engageable by, said braking means, said lower portion of said drive shaft being directly coupled to said drive means.

5. A hydro-extractor as claimed in Claim 4 wherein said drive means comprises an hydraulic motor coupled with, to be driven by, an hydraulic power supply external of said casing.

6. A hydro-extractor as claimed in Claim 5 wherein said power supply provides oil under pressure to said drive means and includes a crossflow valve means and a brake solenoid means connected respectively with said motor and said braking means whereby upon operation of said drive means being terminated oil still circulating through the motor will be relieved across the crossflow valve under pressure to operate as a brake on the motor until, after a time delay, the brake solenoid means is energised to apply said braking means to said disc plate.

7. A hydro-extractor as claimed in any one of the preceding claims wherein a lower portion of said casing includes a mass which enables a greater out- be accommodated- of-balance in the load contained within - 20- 202160

8. A hydro-extractor as claimed in any one of the preceding claims wherein at least one latch engageably connects said cover means and said casing while said basket is being rotated.

9. A hydro-extractor as claimed in claim 8 wherein said at least one latch includes a centrifugal latch assembly comprising a pair of oppositely facing hooked latch members thrown out by centrifugal speed when the basket is rotating to engage a latching member provided on said cover means.

10. A hydro-extractor as claimed in any one of the preceding claims wherein a resilient seal is provided on an underside of said cover means to maintain a reduced pressure created by the rotation of the basket within the casing .

11. A hydro-extractor as claimed in Claim 5 wherein said hydraulic power supply has hydraulic leads connecting it in parallel with one or more additional hydro-extractors.

12. A hydro-extractor substantially as hereinbefore described with reference to the accompanying drawings.