Patent Publication Number: US-2007113994-A1

Title: Apparatus for use in recycling paper material

Description:
The present invention relates to an apparatus, more particularly, but not exclusively, to an apparatus for use in recycling paper type material. The invention also relates to an apparatus for use in making paper material.  
      It is estimated that around 19 million tonnes of waste paper is generated by EU businesses per annum. Although the percentage of waste paper being recycled continues to increase across the EU, the cost of recycling often means that the waste paper generated by small businesses and offices, as well as larger industrial bodies and corporations, is not recycled through paper merchants. In general, this is because most small business and offices do not produce a high enough volume of waste paper to warrant free collection by paper merchants. Therefore, a significant amount of waste paper ends up in landfills and the like, at a cost to both small businesses and the environment.  
      It is an object of the invention to provide an apparatus that addresses the above issues.  
      According to a first aspect of the invention, there is provided an apparatus for use in recycling paper material, the apparatus comprising a housing unit including an inlet for receiving paper material to be recycled and a first processing chamber having means adapted for producing a pulp from paper material, a second processing chamber having a screw device rotatably mounted therein, the screw device being arranged for receiving the pulped material from the first processing chamber and having a pitch configured for driving the pulped material along its length for refining the pulped material, the screw device being further arranged for squeezing liquid from the pulped material, the second processing chamber including means for recovering the liquid squeezed from the pulped material, the unit including a third processing chamber for adding binder to the pulped material after it has passed through the second processing chamber, and means arranged for producing a paper web from the pulped material after it has been processed by the third processing chamber.  
      Conveniently, the means for recovering liquid from the second processing chamber includes means for collecting the liquid and means for recycling the liquid for use in the first processing chamber.  
      The preferred unit is therefore advantageous in that it is configured to recycle its own processing liquid, without the need for a constant mains supply of water for producing pulped material, for example.  
      Preferably, the means for recovering liquid from the second processing chamber includes a plurality of slots arranged in a wall of the second processing chamber, the slots being arranged for allowing liquid to drain out of the chamber in an opposite direction to the effective direction of travel of the pulp material on the screw device.  
      The apparatus in accordance with the invention is preferably of a small-scale construction, for example a unit of a similar size to a domestic food refrigerator, and may be configured for producing absorbent wipes or the like.  
      Not only are small businesses and offices spending money to dispose of waste paper in landfills, they also spend money on paper towels and the like for the cleaning work surfaces, as well as bathrooms and kitchens, for example. Thus, the invention is of particular advantage in that the waste paper generated by small businesses can be converted to paper towel type wipes or the like, thus saving money which might otherwise be spent on both waste paper disposal and paper towels and the like.  
      In alternative embodiments, the invention may also be used for creating packaging or compacted paper for burning.  
      According to a further aspect of the invention, there is provided an apparatus for use in making paper type material, the apparatus comprising a screw barrel arrangement for receiving pulped material paper making material, the screw barrel arrangement including a chamber having an inlet, a screw device rotatably mounted in chamber, the screw device being arranged for receiving the pulped material from the inlet and having a pitch configured for driving the pulped material along its length for refining the pulped material, the screw device being further arranged in the chamber for squeezing liquid from the pulped material, the screw chamber also having means for recovering the liquid squeezed from the pulped material. 
    
    
      Other aspects and preferred features of the invention will be apparent from the foregoing description and the dependent claims.  
       FIG. 1  is a diagram showing a recycling unit according to a preferred embodiment of the invention;,  
       FIG. 2  is a schematic, part cross sectional diagram showing the internal components of the unit of  FIG. 1 ;  
       FIG. 3  is an enlarged schematic view of the screw barrel arrangement from  FIG. 2 ; and  
       FIG. 4  is a schematic, part cross sectional view of part of a recycling apparatus in accordance with another preferred embodiment of the invention. 
    
    
       FIG. 1  shows a recycling apparatus in the form of a micro-scale stand-alone recycling unit in accordance with a preferred embodiment of the invention, indicated at  10 . In this embodiment, the unit  10  is adapted for converting waste paper to general-purpose absorbent paper wipes. The unit  10  is in the form of a portable housing of a similar size to a medium size domestic food refrigerator or office filing cabinet. For example, the embodiment shown in  FIG. 1  has a height of approximately 1.5 m, a width of approximately 0.85 m and a depth of approximately 0.85 m. The unit  10  is particularly suited for use in an office or other business environment, or in a laboratory, in which the wipes generated by the unit  10  can then be used for general cleaning purposes. However, the size of the unit can be customised, as required, for example to the size of a typical food vending machine.  
      Internal components of the unit  10  are shown in  FIG. 2 . The unit  10  includes an inlet in the form of a tray  12 , for receiving waste paper to be recycled (indicated at  11 ). A motor driven paper feed arrangement  14  is provided at one end of the tray  12 , to the right as shown in  FIG. 2 . A paper shredder  16  is arranged beneath the tray  12  for receiving and shredding paper passing from the paper feed arrangement  14 .  
      A first processing chamber  18  having an outlet  19  is arranged adjacent the output end of shredder  16 , to receive shredded waste paper for bleaching and de-inking, and for creating a pulp from the shredded paper. The chamber  18  includes a motor driven processor  20  having blades  21 . The blades  21  are arranged beneath the shredder  16  and are intended to be motor driven for blending the shredded paper as it drops onto the blades, in the manner of a food processor, for processing into a finer particulate material. An ozone input means  22  is also provided in communication with the chamber  18 , for selectively introducing ozone or ozonated water (i.e. water in which ozone has been diffused) into the chamber  18 , as will be described in more detail below. A water tank  24  is arranged above the chamber  18  for supplying water to the chamber  18  for the recycling process, and a solenoid control valve  25  is provided to regulate the flow of water from the tank  24  to the chamber  18 , through electronic actuation. The processor  20  also acts as a viscometer for monitoring the consistency of the pulped material. The processor  20  includes sensors for monitoring the resistance to the rotation of the blades  21 , for monitoring the viscosity of the liquid/paper mixture in the chamber  18 . The chamber  18  includes sensors (not shown) for monitoring parameters within the first processing chamber  18 , such as the ozone level and the pH value of paper/liquid mixture present in the chamber  18 .  
      A compact twin barrel extrusion arrangement, indicated at  26 , is provided in communication with the outlet  19  of the first processing chamber  18 , via a solenoid control valve  27 . The extrusion arrangement  26  is arranged for receiving pulp from the chamber  18 , and includes first and second co-axial extrusion barrels or chambers  28 ,  30 , shown most clearly in  FIG. 3 . As can be seen clearly in  FIGS. 2 and 3 , the first and second barrels  28 ,  30  are connected via a conduit  28 A. The conduit  28 A is of a smaller diameter than the barrels  28  and  30 , and effectively forms a constriction at the left hand end of the first barrel  28 .  
      A motor driven screw, shown diagrammatically at  29 , of varying pitch extends through first and second barrels  28 ,  30  and the conduit  28 A. The pitch of the screw  29  is configured for urging pulp in the direction of the axis of the screw  29 , from right to left as shown in  FIGS. 2 and 3 , and for compressing and refining the pulp during rotation of the screw, as will be described in more detail below. It will be appreciated that the diameter of the portion of the screw  29  extending through the conduit  28 A is smaller than the diameter of the rest of the screw  29 .  
      The walls of the conduit  28 A and the left hand end wall of the first barrel  28  provide a reaction surface in the screw barrel arrangement  26 , against which pulp material is driven in use, as will be described in more detail below.  
      The base wall  33  of the first barrel  28  includes slots, shown clearly in  FIG. 3  at  31 , for passage of water from the pulp. The slots  31  extend across the base wall, orthogonal to the longitudinal axis of the barrel  28 . The slots  31  are also configured so as to be rearwardly inclined at an angle to the longitudinal axis of the screw  29 , which in this embodiment is an angle of 45 degrees. The slots  31  are formed in this manner so as to extend in the opposite direction to the pitch of the screw  29 , as can be seen from  FIG. 3 , so that when pulp is driven by the screw  29 , from right to left as viewed in  FIGS. 2 and 3 , the passage of pulp material down through the slots  31  is limited.  
      A collecting tray  32  is provided beneath the first barrel  28 , for collecting water or matter passing through the slots  31  in the first barrel  28 . The collecting tray  32  is in fluid communication with a condenser tank  34 , via a solenoid control valve  33 . The condenser tank  34  includes a sub-tank  35  arranged for receiving processing water from the collecting tray  32 . A heater  36  is mounted in the sub-tank  35 , for evaporating processing water and thus separating ink and other solids from the processing water. The evaporated water is then recovered, so as to be recycled for use in the unit  10 , as discussed in more detail below.  
      The unit  10  also includes a free piston sterling engine, having a condenser portion  37  and a heater portion  38 . However, it should be noted that any suitable form of heater or condenser may be utilised in preferred embodiments of the invention. The condenser portion  37  is located in the condenser tank  34 , and is used for condensing evaporated water from the sub-tank  35 . The heater portion  38  is used as a dryer for drying recycled paper web produced by the unit  10 , as described in more detail below.  
      The condenser tank  34  has an outlet conduit  40 , which is arranged for supplying condensed water to a sediment tank  42 . A return conduit  44  extends from the sediment tank  42  to the water tank  24 . A motor driven pump  46  is provided in the conduit  44  for circulating water from the recycling process, under pressure, back to the water tank  24 . An optical or refractive sensor  48  is also included in the return conduit  44  for monitoring the solid content of the circulating water from the sediment tank  42 .  
      A vessel  50  for paper binder chemicals is arranged for introducing binder chemicals into the second barrel  30 . The second barrel  30  is connected to an outlet conduit  52  for supplying pulp from the extrusion arrangement  26 , under pressure, to a press apparatus  54  for forming a paper web from the pulp. The press apparatus  54  includes a series of press rollers, indicated at  56 , arranged for the passage of pulp from the extrusion arrangement  26 , to form a continuous web of recycled paper. The press apparatus  54  also includes a dryer  38 , which (as referred to above) is part of the free piston sterling engine  35  mounted in the condenser tank  34 . Beneath the portion of the press apparatus adjacent the dryer, there is provided a series of polished, close-stacked metal rollers known as a “calender”, indicated at  58 , which is adapted for pressing smooth the dried web.  
      The press apparatus  54  terminates at an outlet dispenser portion  60  of the unit  10 , which includes a cutter  62  in the form of a serrated blade, for cutting a length from the recycled web, indicated at  64 , as required.  
      A typical operation of the unit  10  in producing a recycled paper wipe will now be described.  
      Waste paper  11  is inserted into the tray  12  and is fed by the paper feed arrangement  14  into the shredder  16 . The waste paper  11  is shredded and strips of the shredded paper falls into the chamber  18 . Water from the water tank  24  is introduced into the chamber  18 , and the blades  21  of the processor/viscometer  20  are used to agitate and blend the water/paper mixture, i.e. cut through the strips of shredded paper, in the manner of a food processor, for processing the strips into a finer particulate material, to create a pulp from the mixture. Ozone or ozonated water is introduced into the mixture through the ozone input means  22 . The ozone acts as an aggressive agent for de-inking and bleaching the shredded waste paper, as well as sterilizing the pulp by killing organisms in the pulp.  
      The viscometer  20  measures the viscosity of the paper liquid mixture and the resulting pulp and a computerised control unit (not shown) monitors the viscometer output, for controlling the flow characteristics of the mixture/pulp, as required. If more water is required, i.e. to increase the flow of the mixture/pulp, the control unit acts to open valve  25  to allow a volume of water to pass into the chamber  18 . The control unit monitors the data from the sensors in the chamber  18 , for example to monitor the ink concentration within the mixture, or for controlling the amount of ozone being introduced to sufficiently reduce the shredded paper into a bleached pulp. The ozone has the ability to substantially breakdown ink and dirt such as oil or grease. The monitoring of the water content is important for reducing wastewater and in achieving a pulp having a desired, optimal flow characteristic and consistency, with minimum energy consumption. The monitoring of the pulp in this way can also be calibrated and used for regulating the quality of the recycled web to be produced by the unit  10 , for example, for producing a wipe of optimal softness and absorbency.  
      Once a pulp of a desired flow characteristic has been achieved, the control unit acts to open valve  27 , to allow pulp to pass into the first barrel  28  of the extrusion arrangement  26 .  
      The pulp is refined in the extrusion arrangement  26 . The screw  29  is rotated and the pulp is driven along the screw under pressure. The frictional contact between the particulates of the pulp, the internal walls of the barrel  28  and threaded surface of the screw  29 , under pressure as the screw rotates, breaks down the pulp, effectively grinding down the particulates of the pulp. As the screw rotates, pulp matter is forced along the axis of the first barrel  28 , and in to contact with the reaction surfaces formed by the left hand end wall of the barrel  28  and the walls of the constriction formed by the conduit  28 A, as well as against the other internal walls of the first barrel  28 . As the pulp is urged against the reaction surfaces, to push the pulp through the conduit  28 A and into the second barrel  30 , a pressure builds in the first barrel  28 , which causes the pulp present in the first barrel  28  to be compressed. As a result of this compression, liquid is squeezed from the pulp. Therefore, the rotation of the screw converts the pulp to a refined fibrous material having a more consistent particulate size and reduced moisture content.  
      As the liquid is squeezed out of the pulp, it drains through the slots  31  on the base  33  of the first barrel  28 , under gravity, and is collected in the tray  32 , for reprocessing, as will be described in more detail below.  
      The drainage slots  31  are arranged to cooperate with the screw  29  for limiting the passage of the pulp material through the drainage means. In particular, the slots  31  are arranged so that liquid drains from the chamber  18  in a substantially opposite direction to the effective direction of travel of the pulp material. Hence, as the pulp is driven towards the conduit  28 A, the passage of solid material down through the drainage slots  31  is substantially obviated.  
      As the screw  29  continues to rotate, refined pulp material gradually enters the second barrel  30  of the extrusion arrangement  26 . Organic binders, for example starch, are introduced into the second barrel  30 , for binding the fibres of the refined pulp. As the screw rotates, the binder is gradually worked into the refined pulp, which passes further along the screw  29 , and then is moved through the conduit  52 , under pressure from the downstream flow of material in the barrel arrangement  26 , to the press apparatus  54 .  
      In the press apparatus  54 , the bound pulp passes through the rollers  56  to form and mould the pulp into a desired paper web. During passage through the rollers  56 , the heater portion  38  of the engine dries the web. The dried web then passes through the calender, where it is pressed to form a continuous wipe of a desired smoothness.  
      Finally, lengths of the recycled wipe can be cut using the cutter  62  and withdrawn from the unit  10 , as required.  
      As referred to above, the liquid passing to the collecting tray  32  from the first barrel  28 , during refining of the pulp, is collected for reprocessing as follows. The water passes into the sub-tank  35  and is heated by heater  36  to a temperature of over 100 degrees centigrade, to evaporate the collected water. Thereby, ink and other solids are separated from the processing water. The evaporated water is condensed by the condenser portion  37  of the free piston sterling engine and passes through the outlet conduit  40  to the sediment tank  42 . Residue from this evaporation and condensation process is left in the sub-tank  35  or sediment tank  42 . The water collected in the sediment tank can then be re-circulated to the water tank  24 , through the return conduit  44 , by the pump  46 . As the water is pumped through the conduit  44 , it passes through the optical sensor  48 . A change in the refractive index of the water is indicative of an increase in the solid content of the water, to alert the user that the processing water in the tank needs to be replaced.  
      The recycling apparatus described above is advantageous in that it serves as a paper shredder and waste paper receptacle, with the additional ability to recycle waste paper. In the above described embodiment, the unit is adapted for converting waste paper into wipes, for example for laboratory use or for use in kitchens or for general cleaning purposes, or for use as toilet paper. It will be appreciated that the invention will also have similar advantages in schools, hospitals and prisons, as well as on a domestic level. In alternative embodiments, a unit in accordance with the invention may be adapted to produce other products like a compacted paper block for burning and similar use, or to produce packaging.  
      The micro-scale recycling apparatus in accordance with preferred embodiments of the invention is advantageous in that it is able to bleach and sterilize the paper to be recycled using ozone, without the use of standard chemicals, and without producing harmful effluent typically associated with the art. The preferred unit is also further advantageous in that it is configured to recycle its own processing liquid, without the need for a constant mains supply of water, for example.  
      Turning now to  FIG. 4 , an alternative embodiment of a screw barrel arrangement for use in a recycling apparatus in accordance with the invention will now be described, indicated generally at  100 .  
      In this embodiment, the arrangement  100  includes first and second screw chambers  102 ,  104 , with the first screw chamber  102  arranged above the level of the second screw chamber  104 , as can be seen clearly in  FIG. 4 .  
      The first screw chamber has upper and lower walls  106 ,  108 , first and second end walls  110 ,  112  and two side walls (not indicated). An inlet  114  for the chamber  102  is provided in the upper wall  106  adjacent the left hand end of the chamber  102  as viewed in  FIG. 4 . The inlet  114  is provided for coupling the arrangement  100  to the first processing chamber of a unit in accordance with a preferred embodiment of the invention, such as the chamber  18  described above with reference to the unit  10 . Hence, the screw barrel arrangement  100  can be easily incorporated into the recycling unit  10  described above.  
      In this embodiment, however, an alternative form of first processing chamber is illustrated, indicated at  116 . The chamber  116  is configured for receiving shredded or otherwise broken down paper material through an opening  118 . A source of ozonated water  120  is provided in communication with the chamber  116 , via a spray nozzle  122 , for selectively spraying ozonated water onto matter present in the first chamber  116 , for bleaching and sterilising purposes. The chamber  116  is also adapted to be connected to an auxiliary liquid source, such as the water tank  24  described with reference to  FIG. 2 , for producing a mixture from the paper and liquid, for converting to a pulp of the required consistency.  
      A motor driven blender  124  is mounted in the bottom of the chamber  116 , having a plurality of angled rotor blades  126 . These blades  126  are provided for blending a mixture of paper material, ozonated water and liquid from the auxiliary liquid source. The blades  126  are configured to blend the paper material in a manner similar to food processor, so as to form a pulp mixture from the paper material and processing liquids. The blender  124  includes internal means for monitoring the viscosity of the pulp mixture, for producing a pulp mixture of a predetermined consistency. As can be seen in  FIG. 4 , the bottom wall of the chamber  116 , which is indicated at  128 , is inclined to encourage the pulp mixture to move under gravity towards the outlet  130  of the first chamber  116 , in the bottom right hand corner of the chamber as viewed in  FIG. 4 .  
      Control means in the form of a solenoid valve  132  (corresponding substantially to the solenoid valve  27  described above) is provided between the outlet  130  of the first processing chamber  116  and the inlet  114  of the first screw chamber  102 , for regulating the feed of the pulped material into the screw barrel arrangement  100 .  
      Returning now to the description of the first screw chamber  102 , an outlet  134  is formed in the lower wall  108  of the chamber  102 , adjacent the left hand end of the chamber  102  as viewed in  FIG. 4 . The outlet  134  is arranged for the passage of pulped material downwards from the first screw chamber  102 , as will be described in more detail below.  
      A first screw device  136  is provided in the first screw chamber  102 . The screw device  136  is mounted on a rotatable shaft  138  extending through the chamber  102 . One end of the shaft  138  is rotatably received in a bushing  140  adjacent the left hand end of the chamber  102  as viewed in  FIG. 4 . The other end of the shaft  138  extends through the end wall  112  at the second end of the chamber  102 , to the right as viewed in  FIG. 4 .  
      The screw device  136  is arranged for receiving pulped material from the inlet  114 . The screw device  136  has a threaded outer profile, so as to define a plurality of troughs  142  along its length when viewed in cross-section, as shown in  FIG. 4 . The profile of the screw device  136  is configured so that the width of the troughs  142  decreases along the axial length of the screw device  136 , from the right hand end to the left hand end as viewed in  FIG. 4 . Hence, the volume of pulped material that can be accommodated by the screw device  136  at its right hand end, i.e. in the area directly adjacent the inlet  114 , is greater than that the volume of pulped material that can be accommodated at the left hand end of the screw device  136 , as viewed in  FIG. 4 .  
      The pitch of the screw device  136  is configured for urging pulped material towards the outlet  134  of the first chamber  102 , i.e. from right to left as viewed in  FIG. 4 .  
      The maximum diameter of the screw device  136  is substantially constant along its length and is of a dimension selected for close fitting cooperation with the adjacent portions of the internal walls of the first chamber  102 , so as to be almost in frictional contact with the walls. However, it will be appreciated that the spacing between the screw device  136  and the upper and lower walls  106 ,  108  has been exaggerated in  FIG. 4  for illustrative purposes.  
      As can be seen in  FIG. 4 , the screw device  136  extends within the first screw chamber  102 , substantially between the right hand end of the chamber  102  and the outlet  134 . A piston  144  is arranged having an end face  146  at a working clearance, in an inoperative or rest condition, from the left hand end of the screw device  136  and is biased into the rest position shown in  FIG. 4  by a spring  148 . In the rest position, the piston  144  covers the outlet  134 , so as to prevent matter from falling through the outlet  134  to the second screw chamber  104 . It will be appreciated that the end face  146  of the piston  144  provides a spring-biased reaction against the passage of pulped material being driven along the screw device  136 . However, as more material is driven along the screw device  136  against the end face  146 , a build up of pressure occurs, in response to the reaction from the piston and in response to the decrease in pulp-bearing capacity of the screw device  136  along its length towards its left hand end. The increase in pressure causes the pulped material within the troughs  142 , in particular towards the left hand end of the screw device  136 , to be compressed, so as to squeeze out liquid from the pulped material.  
      At a predetermined pressure, the biasing force of the spring  148  on the piston  144  is overcome, so that the material driven against the end face  146  of the piston  144  pushes the piston  144  backwards, to the left as viewed in  FIG. 4 . The material directly adjacent the piston  144  is then able to fall from the screw device  136 , down through the outlet  134  and into the second screw chamber  104 . It will be appreciated that this build up of pressure and movement of the piston  144  to prevent and then enable material to fall into the second screw chamber  104  will continue in a cyclic manner, during the processing of the pulped material in the first screw chamber  102 .  
      A plurality of angled slots  150  are provided in the lower wall  106  of the first screw chamber  102 , for allowing liquid to drain out of the first screw barrel  102 . The slots  150  correspond substantially to the slots  31  described above with reference to  FIG. 3  and extend rearwardly at an angle of 45 degrees, in the opposite direction to the pitch of the screw device  136 . Hence, as the screw device  136  drives pulp mixture from right to left as viewed in  FIG. 4 , the passage of pulped material through the slots  150  is limited.  
      A collecting tray  152  is provided beneath the first screw chamber  102 , for collecting liquid or matter passing through the slots  150 , for reprocessing and recycling in a manner similar to that described with reference to  FIGS. 2 and 3 , for example.  
      The second screw chamber  104  includes a motor driven shaft  154  extending through the chamber  104  and being rotatably mounted in a pair of bearings  156 . As can be seen in  FIG. 4 , a plurality of mixer blades  158  are mounted along the right hand half shaft  154 . The blades  158  are configured for driving the material to the left as viewed in  FIG. 4 . Reservoirs  160  for binder chemicals and perfume chemicals are provided beneath this right hand portion of the shaft  154 . The chemicals are introduced via spray nozzles  162 , so as to bind and add perfume to the material being processed by the mixing blades  158 . The left hand end of the chamber  104 , as viewed in  FIG. 4 , includes a second screw device  164 , which is arranged for collecting the material from the mixer blades  158 . The screw device  164  includes a threaded outer profile having a pitch configured for urging the bound and perfumed material out through an outlet  166 , for further processing as desired.  
      As can be seen from  FIG. 4 , the two shafts  138 ,  154  associated with the first and second screw chambers  102 ,  104  are coupled to a belt drive  168  and motor  170 , for rotating the shafts, when required.  
      The operation of the arrangement  100  will be clear from the above description and the description of the embodiment shown in  FIGS. 2 and 3 , so will not be described further.  
      Although the invention has been described with reference to use in recycling paper material, it will be readily apparent to the skilled addressee that the screw barrel type arrangements described above, having particular regard for  FIG. 3  and the alternative arrangement shown in  FIG. 4 , are suitable for use in other forms of paper making apparatus. For example, the arrangements described with reference to  FIGS. 3 and 4  can be used for processing not only pulps created from recycled paper materials but also for processing pulps created from raw paper making materials. In each case, the screw device for driving the pulped material is arranged in its chamber for squeezing liquid from the pulped material and for refining the pulp prior to further processing.  
      It will also be appreciated that the first processing chamber shown in  FIG. 4  and indicated at  116 , is ideally suited for receiving raw paper making materials and can be coupled to a water source or the like, such as a liquid tank, for use in creating a pulp mixture from the liquid and the raw materials. In such instances, the drainage means in the screw chamber can be arranged in flow communication with the first processing chamber, either directly, or via a liquid tank, as referred to above. The chamber  18  in  FIG. 2  is also suited for this purpose.  
      The use of the compact screw type devices in apparatus in accordance with preferred embodiments of the invention, for processing and refining a pre-blended mixture of liquid and paper materials or the like, is of particular advantage in enabling the apparatus to be incorporated into small, non-industrial scale paper recycling units or paper making units. The applicant hereby reserves the right to seek independent protection via one or more divisional applications derived from this application, for the screw barrel arrangements described above, either for use in recycling apparatus or for other paper making processes and the like.