Patent Publication Number: US-2004058043-A1

Title: Portable cleaning and filtering apparatus

Description:
BACKGROUND TO THE INVENTION  
       [0001] This invention relates to portable cleaning and filtering apparatus.  
       [0002] More particularly the present invention relates generally to a portable apparatus designed to accomplish the rapid and efficient removal of all solid contaminants from a vessel containing liquid such as cooking oil.  
       [0003] Edible cooking oil (often referred to as fat or oil) may be derived from both animal and vegetable sources in solid or liquid form. It is extensively used in the food industry to cook various comestibles.  
       [0004] Fryers are extensively used in the food industry to contain deep, hot cooking oil, in which to cook a wide variety of food which may involve the comestible floating free or being contained in metal wire baskets. In the process, food particles, including batter scraps or breading break off and float free in the fryer to later sink unnoticed in the cooking oil, despite diligent efforts to remove them by the operator. Similarly, small potato fries and other whole food items may escape and descend unnoticed to the bottom of the fryer. As a result, it is not uncommon for several litres of such solid, submerged food waste to accumulate in the lower regions of the fryer awaiting discovery when the fryer is drained of cooking oil for cleaning purposes.  
       [0005] The cooking and heating process continually alters and degrades the physical and chemical properties of cooking oil, which includes the production of free fatty acids. This deterioration is exacerbated if particles dislodged from the food during the cooking process etc are permitted to remain in the hot fryer for an excessive period. This results in reduction of the useful life of the cooking oil. It can also cause a rancid taste to be imparted to the food produced, which loses it&#39;s fresh crispness.  
       [0006] The generation of smoke, foul odour and a lowering of the ignition flash point also accompanies such deterioration of cooking oil.  
       [0007] To beneficially affect the undesirable production of free fatty acids in the cooking oil, it is therefore necessary to minimise the surface area of all food waste particles, suspended or otherwise, that are in contact with the cooking oil. Particles of the size of two microns and larger should be removed from the cooking oil as regularly as practicable.  
       [0008] It has been found that keeping the cooking oil clean by:— 
       [0009] 1. regularly removing the solid, submerged food waste and  
       [0010] 2. filtering the cooking oil on a regular basis, tends to extend the useful life of the cooking oil and increase the quality and appearance of foods which are cooked therein.  
       [0011] The fryer must be drained regularly to permit thorough cleaning, including the removal of carbon deposits on the internal walls of the fryer tank and the removal and discarding of the larger solid food waste that has accumulated on the bottom of the fryer. Where the quantities of food being cooked are large, this cleaning process may have to be carried out several times in a 24 hour period.  
       [0012] The construction of fryers varies widely. For example, hot cooking oil may need to be drained through a drain hole of less than 20 mm inside diameter. Through this aperture as much as 50 litres of cooking oil may need to be removed. In such cases, the flow of the cooking oil can be severely impeded by the presence of the solid submerged food waste previously described.  
       [0013] In addition, certain large electric fryers, generally of older construction and also similar bench mounted models of more recent manufacture, do not allow for the removal of the heating elements to facilitate cleaning. These elements typically extend over virtually all the surface area of the base of the fryer. Where the operator is faced with a heavy accumulation of solid submerged food waste in these type of fryers, the time required to clean a fryer is considerably extended because direct access to scoop out the solid contaminants is extremely limited.  
       [0014] Gas fryers too are not exempt from inadequate sized drain pipes and difficulties of access, particularly where the burner elements are housed in metal tubes passing close together through the lower region of the fryer tank. This makes it not only difficult to effect visual inspection of the base of the interior of the fryer but also equally difficult to access and remove the solid submerged food waste through the top of the fryer.  
       [0015] Even where drain holes are provided of more generous proportions, it is not generally practicable or possible to remove the submerged food waste and scraps by this means. Existing oil filtering systems are typically gravity operated with the hot cooking oil being allowed to drain from the fryer via a drain line and then through a filter element. However, systems are known that clean cooking oil by pumping it through a filter assembly often containing filter paper or other disposable filter media.  
       [0016] A filter powder may be dispersed in the cooking oil to accumulate and form a filter cake on the filter media thereby assisting to mechanically strain suspended solids from the liquid. Filter powders commonly consist of diatomaceous earth, perlite or other filter powders which are made up of various chemical mixtures which if in contact with the pump, may result in reduced pump life and efficiency.  
       [0017] Disposable filter elements such as paper, are an additional cost and may require regular disassembly of the filter assembly to replace the filter element. Tears or other voids in filters may result in particulate matter and filter powder accumulating on heating elements and additional contamination of the cooking oil.  
       [0018] The filtration processes described above are generally disruptive of business, messy and dangerous due to the need to carry out the work near high frying temperatures (130-160C) at which point the viscosity is low enough for the cooking oil to readily pass through known filter elements.  
       SUMMARY OF THE INVENTION  
       [0019] Broadly according to one aspect of the invention there is provided cleaning and oil filtering apparatus for removal of all solid waste material from a container generally containing hot cooking oil and for filtering said cooking oil, including a pump, by which said cooking oil can be moved through an intake means insertable to the bottom of said container, a holding tank for temporary storage of cooking oil filtered through the filtering means, and a discharge means insertable in said container and through which cooking oil from the holding tank can be discharged or cooking oil from said container can be moved through said intake means and filtering means and discharged to said container.  
       [0020] According to a second broad aspect there is provided a method to remove solid waste material and filter hot cooking oil contained in a fryer, said method including the steps of removing oil from a fryer via an intake wand inserted in the fryer, filtering the removed oil and returning filtered oil to the substantially empty fryer to facilitate removal of waste material to said intake wand.  
       [0021] According to a third broad aspect there is provided a method to remove solid waste material and filter hot cooking oil contained in a fryer, said method including the steps of simultaneously removing solid waste material and oil from the fryer via an intake wand inserted in the fryer, filtering the removed oil and moving same to a holding tank, thereafter polishing said filtered oil from the holding tank through primary filtering means and returning polished oil to the fryer to facilitate removal of waste material to said intake wand, refiltering said polished oil and then returning oil held in the holding tank to said fryer. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0022] In the following more detailed description of the invention, reference will be made to the accompanying drawings in which:— 
     [0023]FIG. 1 is a schematic illustration of the filtering apparatus according to the invention,  
     [0024]FIG. 2 is a perspective view of a preferred embodiment of the present invention,  
     [0025]FIG. 3 is a cross sectional view of a primary filter housing, the drawing also showing in exploded view, certain components of the primary filter housing,  
     [0026]FIG. 4 is a perspective view of filter bag press,  
     [0027]FIG. 5 is a cross sectional elevation through a pre-filter housing,  
     [0028]FIG. 6 is a plan view of the pre-filter housing shown in FIG. 5,  
     [0029]FIG. 7 is a cross sectional elevation through an intake wand with insulated handle,  
     [0030]FIG. 8 is a plan view of the intake wand as shown in FIG. 7,  
     [0031]FIG. 9 is a perspective view of an adjustable wand mounting assembly,  
     [0032]FIG. 10 is a perspective view of the discharge wand,  
     [0033]FIG. 11 is a perspective view of an oil displacement cylinder for optional use in the primary filter housing,  
     [0034]FIG. 12 is a plan view of a tool to remove blockage from the intake flexible hose, and  
     [0035]FIG. 13 is a perspective view of a drip catcher, and  
     [0036]FIG. 14 is an elevation view of an electrical control panel of the apparatus. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
     [0037] According to the invention there is disclosed a method and apparatus to facilitate the cleaning of a vessel containing a liquid e.g. cooking oil. The method includes removing the liquid from that vessel and then utilising the liquid to suspend and convey all remaining undissolved contaminants (of whatsoever reasonable dimensions as are commonly encountered), from the vessel.  
     [0038] In the preferred embodiment, the apparatus is constructed substantially of stainless steel. It is designed to universally facilitate the rapid and efficient removal of all food scraps and undissolved particles associated with the deep frying of food, from the diverse and variously constructed deep fryers (cooking vats) currently in use within the commercial food industry.  
     [0039] The apparatus also effectively and efficiently provides for the filtration of the cooking oil contained in the vessel, such that the device may be configured in a light weight portable manner and utilised to enable a professional, commercial deep fryer cleaning and cooking oil filtering service.  
     [0040] The invention includes a pump to withdraw hot cooking oil and all suspended solids from a fryer by means of an intentionally unrestricted large bore intake wand. The oil then passes through a flexible hose into a pre-filter vessel containing a disposable fabric bag filter which as required, may be capable of removing food scraps and particulate down to approximately 50 micron.  
     [0041] After the largest suspended solids have been removed by the fabric bag filter, the cooking oil traverses the pump and is directed under low pressure into a primary filter vessel containing a pressure gauge, and a final polishing filter. On exiting the polishing filter, the filtered cooking oil may then be directed by a three way valve either into a holding tank, or returned back into the fryer by means of a flexible discharge hose and wand.  
     [0042] The method incorporates removing, filtering and transferring almost all of the cooking oil contained in the fryer into the holding tank. Thereafter, any food scraps still present in the fryer may be quickly removed by recycling the remaining cooking oil in the fryer through the filtration system described above by means of the intake and discharge wands until all visible contaminants have been removed from the fryer.  
     [0043] The flow of filtered cooking oil returned to the fryer through the discharge wand enables any remaining food scraps to be dislodged and suspended in the flow of cooking oil across the bottom of the fryer, which can then be directed to and withdrawn by means of the intake wand. To achieve this, the volume of cooking oil flowing from the discharge wand must equal that which is withdrawn by the intake wand. The discharge wand therefore is preferably constructed of pipe of narrower bore, relative to the intake wand, so as increase the fluid discharge velocity and enhance the cleaning achieved by the cooking oil as it is returned to the fryer.  
     [0044] An adjustable arm is provided on which to temporarily mount both wands about the fryer during use.  
     [0045] To return the cooking oil in the holding tank, a second three way valve is provided to enable cooking oil from the holding tank to also be fed directly to the pump. Both three way valves provide for the drainage of the pipe system through a separate drain valve located adjacent to the pump.  
     [0046] The two stage filtering system is fabricated from commercially available components and filter media and ensures that where treating material is not utilised, a high flow rate at low filtration pressures is achieved.  
     [0047] The pre-filter housing contains the aforementioned disposable fabric bag filter of large holding capacity.  
     [0048] The primary filter housing is configured to accept a disposable fabric bag filter which should be capable of removing particulate in the 1-5 micron range.  
     [0049] The open end of the filter bag contains a wire ring. Above the ring is a sprung loaded steel washer which under the influence of two compression springs, positively locates and seals the wire ring (and hence the open end of the filter bag) against the flange seat provided around the inside of the wall of the primary filter housing.  
     [0050] Other commercially available filtration components having substantially the same capabilities, ease of cleaning and economic viability as described above, may be substituted for any part or all of the filtering system set forth or may be additionally deployed to create a multistage filtering system for the purposes described herein.  
     [0051] An electrical panel provides a speed controller to regulate the motor and pump, a switch to override the trigger switch on the insulated handle of the intake wand, a motor reversing switch and a high voltage ‘on/off’ switch.  
     [0052] The device is of suitable weight displacement and external dimensions to facilitate movement in and through confined spaces, including vehicle access by means of suitably placed moving handles, and may be configured to accept stair mounting wheels.  
     [0053] To more fully describe a preferred embodiment, reference is first made to FIG. 2. A handle  80  is fixed to frame  82 , the latter being substantially constructed of square section stainless steel tubing. On the frame  82  is disposed drip tray  79  which creates a sealed upper surface to the apparatus for the protection and ease of cleaning of the electrical and other equipment located beneath.  
     [0054] Upstand  81  is provided around three sides of the perimeter of drip tray  79 . This contains any spilt cooking oil which may then be safely directed into holding tank  2  located at the unrestricted side of drip tray  79 .  
     [0055] Disposed through drip tray  79  is pre-filter housing  15 , primary filter housing  23 , pipe  42 , and pipe  44 . The pre-filter housing  15  is in communication with an intake wand  53  by means of flexible hose  60  and pump  49  by means of pipe  45  and three way valve  50 . Mounted atop primary filter housing  23  is pressure gauge  24 .  
     [0056] The primary filter housing  23  is in communication with  
     [0057] pump  49  by means of check valve  39  or two way ball valve  31  and pipe  44 ;  
     [0058] discharge wand  61  by means of flexible hose  64 , pipe  42 , three way valve  51  and pipe  43 ; and  
     [0059] holding tank  2  by means of three way valve  51  and pipe  43 .  
     [0060] Intake wand  53  is preferably formed from not less than 32 mm OD stainless steel round tube having insulated handle  56  mounted thereon.  
     [0061] Flexible hose  60  is preferably formed from not less than 37 mm ID convoluted PTFE tubing with single stainless steel braid.  
     [0062] Discharge wand  61  is preferably formed from not less than 25 mm OD stainless steel round tube, having insulated handle  62  mounted thereon.  
     [0063] Flexible hose  64  is preferably formed from not less than 18 mm ID convoluted PTFE tubing with single stainless steel braid.  
     [0064] Pipe work is preferably formed from not less than 25 mm OD stainless steel round tube.  
     [0065] Electrical control panel  8  is located to provide convenient access to control electric motor  46 . Motor  46  is coupled to pump  49  by means of small pulley wheel (not shown), single V belt  92  and large pulley wheel  93  and mounted on a steel plate  94  fixed to frame  82 . Motor  46 , is preferably 4 pole three phase and 375 watt.  
     [0066] Large pulley wheel  93  is equipped with drive nut  48  fixed to the end of the drive shaft of pump  49 , to which a socket and bar may be attached to free pump  49  should it become seized with congealed fat. When not in use, drive nut  48  is covered by a protective skirt panel (not shown).  
     [0067] Pump  49  is a gear pump which may be equipped with a pressure by pass valve (not shown), and capable of reliably withstanding the high fluid temperatures encountered (approximately 200C maximum) and the abrasion of cooking oil treatment filter aids and particles of food waste. In the preferred form it is capable of delivering a fluid flow rate of 50 litres per minute or thereabouts under normal operating conditions.  
     [0068] Holding tank  2  is preferably of at least 50 litres capacity. It contains a holding tank discharge filter  6 , an extension  4  of pipe  43  and wand transit mount  5 . The bottom surface of holding tank  2  is fluted to facilitate complete drainage of cooking oil into the outlet orifice into which is inserted holding tank discharge filter  6 . This filter  6  includes a perforated tube or perforated flat sheet providing protection to pump  49  from damage by hard extraneous objects inadvertently entering holding tank  2 .  
     [0069] When the apparatus is transported in “standard mode” with handle  80  and motor  46  positioned flat against the tray of a transportation vehicle, the extension  4  of pipe  43  into holding tank  2  prevents residual cooking oil held therein from re-entering pipe  43 .  
     [0070] Splashes from cooking oil held in holding tank  2  are contained by a fluid retaining lip  3  which also prevents leakage of any residual cooking oil when the apparatus is transported in the “standard mode”.  
     [0071] When not in use, intake wand  53  and discharge wand  61  are mounted on wand transit mount  5  by means of mounting hooks  54  and  63  respectively and retained in position by a cord (not shown). The cord has one end attached permanently and one end attached removably to handle  7  which is mounted externally at the top of the front face of holding tank  2 . Handle  7  facilitates manoeuvring of the apparatus during use.  
     [0072] Wand support mechanism  65  is mounted externally on the left hand front corner face of holding tank  2  to provide continuously adjustable mounting for intake wand  53  and discharge wand  61  when in use.  
     [0073] A tool box (not shown) is mounted within the upper open aperture  78  of holding tank  2  for convenient access. The tool box may be fashioned to cover and protect the open aperture  78  from the entry of extraneous objects when the apparatus is not in use, or a separate cover (not shown) may be fabricated for the purpose.  
     [0074] Rear wheels  83  may be of the stair mounting variety or simple fixed wheels mounted at an angle to the horizontal so as to protrude to the rear of the frame and facilitate mounting of closed stair risers. Non-floor marking impact absorbing tyres (particularly suitable pneumatic tyres) are preferred. Front wheels  84  are preferably of the lockable swivel castor type equipped with non-floor marking (pneumatic) impact absorbing tyres.  
     [0075] D handle  77  at the lower front of the apparatus assists with lifting the front of the apparatus in order to rotate the apparatus onto a transport tray of a vehicle to achieve “standard mode” transportation.  
     [0076] All pipe work is configured to provide maximum fall to enhance free and thorough drainage of cooking oil whether the apparatus is in the attitude enabling use or in “standard mode” transportation, to thus avoid fat (oil) collecting within the apparatus to cause obstructions if such collections then solidify at low ambient temperatures. Drain valve  52  is installed at the lowest point of the pipe system yet with sufficient clearance to allow a drip catcher  40  to be mounted thereunder on mounting rod  47 .  
     [0077] All components are constructed and finished to meet food handling safety standards.  
     [0078] Referring to FIG. 3, there is shown a primary filter assembly in which a disposable filter bag  27  is contained in a perforated stainless steel support tube  28  having a solid base  29 . The upper edge of support tube  28  is contained within and welded to flange  30  which is disposed around and welded to the inner wall surface of filter housing  23 .  
     [0079] Mounting tabs  35  (two in number) are fixed to the upper inner wall surface of filter housing  23 . These provide means by which compression springs  36  (see FIG. 4) may exert downwards pressure against filter bag press washer  34  (see FIG. 4) to compress and seal the upper edge of filter bag  27  containing wire ring  85  against flange  30 .  
     [0080] Cooking oil enters primary filter housing  23  by intake  32  and passes through check valve  39 , to then be filtered by filter bag  27  before exiting filter housing  23  through the discharge orifice  33 .  
     [0081] Check valve  39  provides an enhanced safety feature such that when electric motor  48  is switched off, (see FIG. 2) hot cooking oil under pressure within the primary filter bag  27  is prevented from being returned through pipe  44 , pump  49 , pipe  45  and three way valve  50  to either enter holding tank  2  and possibly come forcibly and dangerously into contact with the operator of the apparatus or to return with contaminants to the fryer  1  by means of pre-filter housing  15 , flexible hose  60  and intake wand  53 .  
     [0082] At the discretion of the operator, cooking oil delivered through intake  32 , may also be directed to separately enter primary filter housing  23  by means of two way ball valve  31 . Oil thus entering primary filter housing  23  bypasses filter bag  27  and becomes available for use to remove blockages occurring beyond discharge orifice  33 .  
     [0083] Pressure gauge  24  and handle  26  are mounted on the lid assembly  25 , which threadedly attaches to filter housing  23  and retains a synthetic seal (not shown) disposed around the upper perimeter of filter housing  23 .  
     [0084] In FIG. 4, a filter bag press is shown which comprises two compression springs  36  disposed around retaining guide rods  38  and welded to the upper surface of filter bag press washer  34 . Compression springs  36  are retained under removable handle  37 , the ends of which are constrained laterally and vertically by retaining guides  38 .  
     [0085] Pairs of mounting tabs  35 , are set opposite each other at a suitable height above flanges  30  or  18  and separately welded to the inside of the primary filter housing  23  and pre-filter housing  15  (see FIG. 5). When the ends of removable handle  37  are engaged within mounting tabs  35 , the springs are compressed and pressure thus exerted, engages press washer  34  against wire ring  85  to seal filter bags  27  or  91  (see FIG. 5) against respective flanges  30  or  18 .  
     [0086] By disengaging removable handle  37  from mounting tabs  35 , the filter bag press may be removed from primary filter housing  23  or pre-filter housing  15  for cleaning purposes. This procedure similarly permits filter bags  27  or  91  to be withdrawn for cleaning or replacement.  
     [0087] Referring to FIG. 5, there is shown the pre-filter assembly. This includes a disposable filter bag  91  contained in a perforated stainless steel support tube  95  having a perforated base and capacity of approximately 5 litres. The bag can be a 78 um polyester cloth that is reversible, resistant to adhesion of contaminants to therefore require little maintenance other than emptying, reversing, a quick scape down to remove any adhesions and replacing in the perforated support tube  95  contained in the housing.  
     [0088] Within disposable filter bag  91  is disposed a wire support frame  19  having grip rings formed at the upper ends and a support disc  20  fixed within the base perimeter. Support frame  19  thus prevents deflation of filter bag  91  under reverse fluid flow conditions and facilitates removal of food scraps contained within filter bag  91  for disposal.  
     [0089] The upper edge of support tube  95  is contained within and welded to flange  18  which is disposed around and welded to the inner wall surface of pre-filter housing  15 . The perforated base of support tube  95  is off set approximately 40 mm from the base of pre-filter housing  15 . This ensures that filtrate extracted from cooking oil passing through filter bag  91 , is subsequently rendered substantially drained of liquid cooking oil.  
     [0090] Mounting tabs  35  (two in number) are fixed to the upper inner wall surface of pre-filter housing  15 . These provide means by which compression springs  36  (see FIG. 4) may exert downwards pressure against filter bag press washer  34  (see FIG. 4) to compress and seal the upper edge of filter bag  91  containing wire ring  85  against flange  18 .  
     [0091] Cooking oil enters pre-filter housing  15  by intake  21  and passes through filter bag  91  and perforated support tube  95  before exiting housing  15  through discharge orifice  22 .  
     [0092] Pipe work presenting leading edges to the incoming flow of cooking oil are machined  86  to reduce drag and thereby minimise the likelihood of blockages from food scraps and other particulate.  
     [0093] Handle  17  is mounted on lid assembly  16 , which threadedly is attached to pre-filter housing  15  and retains a synthetic seal (not shown) disposed around the upper perimeter of pre-filter housing  15 .  
     [0094] An intake wand handle (see FIG. 6) includes an insulated handle  56  bored through it&#39;s base to accept control cable conduit  58  in communication with trigger switch  59  mounted centrally in slip restraint plate  57 . Insulated handle  56  is preferably fabricated from wood for thermal insulation purposes. It is contoured along it&#39;s face adjacent to flexible braided hose  60  to provide finger grips  89  for the convenience and safety of the operator. This effect is further enhanced by the provision of slip restraint plate  57 , the same being fixed by suitable wood screws  87  to the upper face of insulated handle  56 .  
     [0095] Insulated handle  56  is further bored through it&#39;s base to provide a stopped hole to accept mounting rod  55 . The rod  55  is being secured by metal thread screws  88  or the like passing through insulated handle  56  and into or therethrough. The opposite end of rod  55  is welded to intake wand  53  adjacent to the junction with flexible hose  60 .  
     [0096] Control cable conduit  58  enables thermally suitable cable (not shown) to communicate from the electrical control panel  8  to the trigger switch  59  which for purposes of safety, is of a type that assumes the electrically off position when finger pressure is released from it&#39;s operating button. Control cable conduit  58  is strapped at appropriate centres to flexible hose  60  by means of stainless steel cable clips (not shown).  
     [0097] An internal spring (not shown) is inserted to extend the full length of flexible intake hose  60  to prevent the vacuum created by pump  49  from collapsing the internal PRFE lining of the hose, should the intake end of the intake wand become blocked during use.  
     [0098] Mounting hook  54  is provided to secure intake wand  53  as required to either wand transit mount  5  or mounting estension  73  (see FIG. 7) located on wand support mechanism  65  (see FIG. 2).  
     [0099] Materials utilised, wall thicknesses and dimensions are chosen and fashioned to achieve lightness of weight for operator comfort.  
     [0100] Referring to FIG. 7, there is shown a discharge wand and mounting assembly. The discharge wand  61  incorporates insulated handle  62  preferably fabricated from wood to achieve suitable thermal insulation. Discharge wand  61  is disposed on mounting extension  72  preferably at an angle of 25 degrees from the vertical by engaging mounting hook  63  into mounting hole  76 .  
     [0101] Mounting extension  73  and further mounting hole  76  are provided to similarly and separately mount intake wand  53 . Together with mounting extension  72  and mounting hole  76  they are adjacently located at the forward end of horizontal square tube  69 , thus forming part of mounting assembly  65  (collectively shown) which comprises:— 
     [0102] 1. The aforementioned mounting extensions  72  &amp;  73  and mounting holes  76  ( 2 )  
     [0103] 2. Horizontal square tube  69   
     [0104] 3. Horizontal square tube  70   
     [0105] 4. Square sleeve  71   
     [0106] 5. Fulcrum  74   
     [0107] 6. Vertical round pivot tube  68   
     [0108] 7. Height adjustment  66   
     [0109] 8. Mounting sleeve  67   
     [0110] Horizontal square tube  69  is able to slide continuously along it&#39;s length within square sleeve  71 . It thus provides means by which mounting arms  72  and  73  can be extended forward beyond the front of the apparatus to suitably mount discharge wand  61  or intake wand  53  into fryer  1  (see FIG. No  1 ).  
     [0111] Square sleeve  71 , is mounted on fulcrum  74 , located adjacent to the rear facing extremity of horizontal square tube  70 . The forward facing extremity of horizontal square tube  70  is fixed atop vertical round pivot tube  70  which is free to continuously rotate within mounting sleeve  67 .  
     [0112] As vertical round pivot tube  70  is rotated, horizontal square tube  70  also rotates on it&#39;s pivot point atop vertical round pivot tube  70 . When in use, horizontal square tube  70  is preferably but variously positioned at 90 degrees from the side of holding tank  2 . Square sleeve  71 ′ and fulcrum  74  are thus similarly and if required, adjustably offset from the side of holding tank  2 .  
     [0113] Upper horizontal square tube  69  is retained at it&#39;s rear facing extremity within square sleeve  71 . It is similarly offset from the side of the apparatus, yet still able to rotate on fulcrum  74 . By utilising the rotation of square sleeve  71  and the longitudinal travel of upper horizontal square tube  69  within square sleeve  71 , it is possible to variably and conveniently position discharge wand  61  or intake wand  53  in the fryer  1  from an offset angle by means of wand support mechanism  65 . Thus it allows the operator unimpeded working space in front of the apparatus and along and behind the front wall of the fryer  1 .  
     [0114] Vertical round pivot tube  70  may also be continuously adjusted along it&#39;s length to correspondingly affect the height of the horizontal components of the wand support mechanism  65 . Height adjustment is secured by means of height adjustment mechanism  66  whereby vertical round pivot tube  68  is passed through a hinged flat upper tab that is spring loaded downwards to interfere by friction with the downwards travel of vertical round pivot tube  68  in mounting sleeve  67 . As the upper tab is increasingly rotated downwards from a disengaged horizontal position, so also is vertical round pivot tube  68  increasingly deflected against the inner surfaces of both mounting sleeve  67  and the upper tab, thus preventing it&#39;s further descent.  
     [0115] Mounting sleeve  67  is fixed to the left hand front face of holding tank  2  such that when in parallel alignment, the left hand side face of horizontal square tubes  69  and  70  can be longitudinally positioned adjacent to and inside upstand  81  at the left hand edge of drip tray  79 .  
     [0116] Referring to FIG. 11 a sealed cooking oil displacement cylinder  90  is shown for optional use with primary filter bag  27 , to minimise the amount of cooking oil retained in filter bag  27  when being withdrawn from primary filter housing  23  for cleaning or replacement.  
     [0117] Intake hose cleaner  75  is schematically shown in FIG. 12 comprising round wire rod handle  96 , suitable length of flexible spiral wire tube  97  and circular wire rod cleaning head  98 . The cleaning head  98  is inserted into intake wand  53  to reach and dislodge food scraps found therein.  
     [0118] A drip catcher  40  is shown in FIG. 13 and is capable of receiving residual discharge from the apparatus by means of drain valve  52  after initial drainage of the pipe work and vessels of the apparatus. Mounting hooks  41  are attached to mounting rod  47 , enabling drip catcher  40  to thereby remain perpendicularly beneath drain valve  52 , irrespective of whether the apparatus is in use or in “standard mode” transportation. Without limitation, drip catcher  40  is primarily intended for deployment as soon as the apparatus has been placed in “standard mode” transportation.  
     [0119] The electrical control panel is depicted in FIG. 14 and contains speed control device  9  capable of continuously varying and maintaining the speed of motor  46 . Additionally, for safety purposes, speed control device  9  is able to ramp the attainment of a given increased speed setting according to prior adjustment and optionally to stop and to apply an electrical brake to motor  46  immediately upon initiation by the operator. Thus control of unwanted or unexpected discharge of cooking oil from the apparatus under the influence of mechanical energy or fluid pressure transferred to the pump  49  can be achieved.  
     [0120] The following additional controls are mounted in electrical control panel  8 :— 
     [0121] 1. Trigger override switch  12  which enables the operator to carry out certain functions such as to empty holding tank  2  into fryer  1  without being constrained to hold and operate trigger switch  59  which in this instance, when discharge wand  61  is suitably mounted on mounting arm  72  leaves the operator free to carry out other duties.  
     [0122] 2. Speed control knob  11  provides analogue speed control in preference to digital microswitch speed adjustment.  
     [0123] 3. LCD display  10  provides visual means to accurately determine the speed of electric motor  46 .  
     [0124] 3. Master on/off switch  13  enables the operator to switch the mains power supply to the apparatus.  
     [0125] Reversing switch  14  provides for the reverse operation of motor  46  to facilitate clearing blockages or draining pipe work.  
     [0126] To assist in the further understanding of the construction of the apparatus according to the present invention, reference will be made to the methodology used when cleaning oil from a fryer.  
     [0127] The temperature of the cooking oil in fryer  1  is adjusted to approximately 160° C. and then the heat turned off. The operator then removes the element protection tray or mesh using a stainless steel wire hook or pliers or similar. Where appropriate, electric elements are also withdrawn.  
     [0128] As shown in FIG. 1 the intake wand  53  and discharge wand  61  are inserted into the fryer  1  on the wand support mechanism  65  with the open ends of the wand set as near as practicable to the bottom but clear of any fixed electric elements, temperature sensors or other obstructions. The drain valve  52  and two way ball valve  31  are then turned off and lids  25  and  16  of filter housings  23  and  15  are securely fastened to form suitable fluid seals.  
     [0129] Valve  50  is set to direct cooking oil from fryer  1  to pump  49  by means of intake wand  53 , flexible hose  60 , pre-filter housing  15  and the balance of pipe  45 . Valve  51  is set to direct cooking oil from pump  49  to holding tank  2  by means of pipe  44 , check valve  39 , primary filter  23  and pipe  43 . The speed control device  9  on control panel  8  is adjusted by means of speed control knob  11  to operate motor  46  at high speed.  
     [0130] Actuation of trigger switch  59  on intake wand handle  56  activates motor  46  which is coupled to pump  49  thereby enabling the operator to manipulate the intake wand  53  and vacuum out virtually all of the cooking oil in fryer  1  to the holding tank  2 . At the same time the operator endeavours to withdraw as much food scrap from the bottom of the fryer  1  as possible. When this operation is completed, the pump  49  is stopped and the intake wand  53  is returned to the wand support mechanism  65 .  
     [0131] The operator then removes accumulated encrustations of food particles and carbon from the interior of the fryer one using a steel wire pad under hand pressure. Valve  50  is then set to direct cooking oil from holding tank  2  to pump  49  by means of pipe  45 . Valve  51  is adjusted to direct cooking oil from pump  49  along pipe  44  to primary filter  23  thence to fryer  1  by means of pipe  42 , flexible hose  64  and discharge wand  61 . By manipulating the speed control knob  11  on electrical control panel  8 , the speed of motor  46  can be adjusted to “very slow”.  
     [0132] By utilising trigger override switch  12 , flow of filtered cooking oil is initiated from the discharge wand  61 , so that the cooking oil is discharged to wash the dislodged encrustations adhering to the internal wall surface thereof to the bottom of the fryer  1 . In so doing the operator ensures that sufficient cooking oil is returned to the fryer to provide a fluid seal at the end of the intake wand  53  as subsequently required.  
     [0133] The trigger override switch  12  is then turned off. The speed control knob  11  is then adjusted to operate pump  49  at high speed and valve  50  set to withdraw cooking oil from the fryer  1  to pump  49 . This is achieved through intake wand  53 , flexible hose  60 , pre-filter housing  15  and pipe  45 .  
     [0134] By holding insulated handle  62  of discharge wand  61  in one hand (e.g. the left hand) and then holding the intake wand handle  56  in the other hand, the operator presses trigger switch  59  to operate pump  49  at high speed. The operator can thus use filtered cooking oil from discharge wand  61  to wash clean the bottom of the fryer and electric elements (if any) and jet the remaining food scraps and other waste material towards and into intake wand  53 . This technique is used to remove all remaining food scraps and wastes from the fryer.  
     [0135] When fryer  1  is visually free from food scraps and waste, pump  49  is kept running while the operator returns the discharge wand  61  to the wand support mesh mechanism  65  and then adjusts Valve  51  to redirect cooking oil to the holding tank  2  by means of pipe  43  and proceeds to withdraw as much oil as possible from holding tank  2 .  
     [0136] Thereafter the operator holds intake wand  53  aloft and catching any dripping cooking oil or discharge in a stainless steel jug, moves it to a point above the holding tank  2 . By maintaining the intake wand  53  above holding tank  2  and clear of the cooking oil, the pre-filter system  15  in particular is drained of cooking oil, achievement of which is evidenced by the emergence of air bubbles into holding tank  2  from the end of pipe  43 . The pump  49  can then be stopped and the intake wand  53  attached to wand transit mount  5  by means of mounting hook  54 .  
     [0137] Resetting valve  50  enables the return of cooking oil from holding tank  2  to the fryer  1  by means of pipe  45 , pump  49 , pipe  44 , check valve  39 , primary filter  23 , pipe  43 , valve  51 , pipe  42 , flexible hose  64 , and discharge wand  61 . This action is initiated using override switch  12 .  
     [0138] While the fryer  1  is refilling, the wand support mechanism  65  is lifted to set discharge wand  61  above and clear of the final level of cooking oil in the fryer. Food scraps and waste contained in filter bag  91  within pre-filter  15 , can then be emptied.  
     [0139] When the holding tank  2  is empty, operations of pump  49  is continued until the primary filter housing  23  has been to the extent possible, fully drained into the fryer. As required, the operator can then replace filter bag  27  with a clean filter bag. The discharge wand  61  is then returned to the wand transit mount  5  in holding tank  2  by means of mounting hook  63  and secured together with intake wand  53 . The wand support mechanism  65  is then folded away and secured.  
     [0140] Operation on the fryer is completed by reassembling the fryer and cleaning its exterior.  
     [0141] The operator will then drain the apparatus by setting valve  50  and  51  to their common drain position, and opening drain valve  52  at pump  49  to then capture discharging cooking oil in a stainless steel jug. When holding tank  2  and pre-filter  15  have drained, pump  49  is operated in reverse using reversing switch  14 . This drains pipe  44 . Any cooking oil recovered is returned to the fryer following which the drain valve  52  is closed.  
     [0142] This completes the cleaning operation whereupon the power cord to the apparatus can be disconnected and the apparatus and tools etc, packed up. The apparatus can then be returned to a transport vehicle. By grasping D handle  77  and lifting and rotating the apparatus and sliding it upon the rear surface of frame  82 , the apparatus can be positioned and separately secured onto a vehicle transport tray. Drip catcher  40  is then mounted on mounting rod  47  and drain valve  52  opened so residual cooking oil in the apparatus may continue to drain during transit.  
     [0143] When cleaning multiple fryers, it is not necessary to return intake wand  53  to wand transit mount  5  before moving the apparatus from one fryer to the next. The operator simply remounts intake wand  53  onto wand support mechanism  65  and raises the whole assembly so that both wands  53  and  61  clear the top of the fryer as the apparatus is wheeled to the next fryer.  
     [0144] Then, where the chef is agreeable, the apparatus enables the operator to more quickly clean a series of adjacent fryers by eliminating the need to pump the cooking oil from any fryer twice, except for oil contained in the first one. This is achieved by emptying the first fryer into the holding tank  2  and then pumping the cooking oil in the second fryer, directly into the first fryer and so on and so forth.  
     [0145] To those skilled in the art it will be apparent that the preferred form of the invention and method of use is open to modification. For example:— 
     [0146] The apparatus may be utilised to rapidly remove spent cooking oil and food waste from a fryer by adjusting the three way valves so that said oil bypasses the primary filter, enabling the partially filtered cooking oil to be discharged more directly into a suitable waste container.  
     [0147] The components within the pre-filter housing may be modified by equipping the open end of the perforated tube with a flange and upward facing handles to enable said flange to removably seat atop and seal against the flange disposed around the inside of the pre-filter housing. The perforations in the tube would be reduced in size to satisfactorily strain larger food particles from the cooking oil passing therethrough. The strainer basket thus created, would have a capacity to hold approximately litres of such food particles.  
     [0148] An intermediate filter may be incorporated within the primary filter housing to further extend the service life of the primary filter bag before cleaning becomes necessary.  
     [0149] As previously disclosed, cooking oil discharged from pump  49  may be utilised to remove obstructions occurring in the fluid pathway beyond primary filter housing  23 , for which purpose and physical convenience, the facilitating valve is shown deployed between the intake pipe line to the primary filter and a hole inserted in the wall of the primary filter housing just below the internal flange. It will be apparent that other suitable fluid pathways are also possible.  
     [0150] The present invention thus provides a method and portable apparatus which can be used universally to simplify the cleaning of a fryer and effectively remove particulate material from the cooking oil. The amount of labour required to carry out this operation is less than would conventionally be required using known equipment.  
     [0151] The filtering operation can be carried out without the use of filter aid treatment powders which when sprinkled into the fryer to achieve even disbursement therethrough, may thereby generate airborne dust capable of inhalation. Such powders may contain silica, the inhalation of certain forms of which is considered a hazard to human health.  
     [0152] Nonetheless, the filtering operation may be carried out in conjunction with filter aid treatment powders although a coarser filtration mesh may require to be deployed in the pre-filter housing. The method and apparatus does not result in any contamination of the cooking oil by the treatment material.  
     [0153] The filtering operation can also be carried out together with technologies that reduce the level of free fatty acids which are known to increase during the cooking process, the presence of which degrades performance of the cooking oil.  
     [0154] The filtering apparatus employs substantially re-useable filter elements to provide for relatively economical filtering of cooking oil.  
     [0155] The apparatus provides facility to continuously vary the pump speed, which control enhances operator safety by enabling splash back from the discharge wand to be prevented when refilling the fryer. Also such variation and control of the pump speed provides the capability of safely washing contaminants from the walls of the fryer with a minimum discharge of cooking oil from the discharge wand. These and other safety features lead to the method and apparatus being able to be practised with safety of the operator in mind.