GB2180777A

GB2180777A - Comminuting apparatus and method

Info

Publication number: GB2180777A
Application number: GB08522716A
Authority: GB
Inventors: Josef Karel Pivonka
Original assignee: Tweedy of Burnley Ltd
Current assignee: Tweedy of Burnley Ltd
Priority date: 1985-09-13
Filing date: 1985-09-13
Publication date: 1987-04-08
Also published as: GB8522716D0; GB2180777B

Abstract

Paper based bedpans are inserted into a comminuting chamber 10, and a lid is closed. Water is fed to the chamber via a passage 24 and via a spray nozzle on the underside of the lid. A cutter then rotates to comminute or macerate the paper based products and any solid waste they may contain. A drain outlet or trap discharge 22 is then opened to allow the water and comminuted products to pass through the trap and out to the drain. <IMAGE>

Description

SPECIFICATION Comminuting apparatus and method The present invention relates to a comminuting apparatus and method and is particularly, although not exclusively, concerned with the comminuting of paper based bedpans and bottles containing solid or liquid waste products.

In prior arrangements for comminuting paper based bedpans, the bedpans are located in a chamber in which the lower region includes a plurality of impact blades rotatable about a vertical axis. Water is sprayed onto the bedpans from the top of the chamber and the blades rotate to comminute the bedpans. The rotary action of a member carrying the blades is also arranged to force the material in the chamber out through a sieve located at a lower level in the chamber than the blades.

A major problem when comminuting paper based bedpans is that they are highly floatable and accordingly, if no provision were made to force the material out through the sieve, all of the paper based material would tend to remain floating in the top region of the water in the chamber with none of the comminute material being expelled from the chamber. The provision of a sieve is necessary as large pieces of the bedpans tend to be forced out of the chamber before they have been reduced to a sufficient size for them to be safely passed out to a drain.

As the rotary action causing the movement of the blades is also required to force the comminuted parts out through the sieve at a lower level than the rotating blades, it is necessary that the rotary axis be vertical. This is a disadvantage as one or more of the bedpans may tend to be located in the region of the pivotal axis with the consequence that it is not comminuted sufficiently, or even at all.

The incomplete comminuting of the bedpans has been found to be a particular problem when the machines are not loaded with bedpans to their maximum capacity.

According to one aspect of the present invention, comminuting apparatus includes a chamber in which material arranged to be comminuted is capable of being located, liquid supply means arranged to at least partially fill the chamber with liquid, and rotatable comminuting means located in the chamber, the apparatus further including closure means selectively operable to prevent or allow the contents of the chamber to pass out of a lower region of the chamber. Thus the material to be comminuted is able to remain in the chamber until it has been sufficiently comminuted prior to the closure means allowing the contents to pass out.

The closure means may be automatically operable.

The rotational axis of the comminuting means may extend across the chamber and may be substantially horizontal. Thus the ma teriai to be comminuted may not tend to rest on the pivotal axis with the consequential incomplete comminuting thereof. Furthermore, a more effective comminuting action may be provided by the comminuting means as a result of the rotational axis extending across the chamber. A plurality of comminuting members may be provided on the communiting means, and these may be arranged substantially in a helix. The comminuting members may be arranged in two substantially helical configurations offset approximately 180 from each other.

The comminuting means may be arranged to be stationary during discharge of the products from the chamber which prevents the products from being repeatedly splashed around the chamber.

The outlet of the chamber may comprise an opening slightly smaller than the products which are to be comminuted. Thus the products will not tend to become stuck in the outlet opening and will float or be driven back to the region where comminuting occurs, and yet rapid discharge of the products in the chamber is permitted when the closure means allow material to pass out of the chamber.

Fluid may be arranged to be supplied to the chamber from either or both an upper and lower region of the chamber. The fluid supply may be arranged to be supplied to the chamber before the comminuting means begins to rotate. The fluid supply to the chamber may be arranged to cease prior to comminution commencing or prior to comminution being completed. The fluid supply may be arranged to recommence either before the comminution has been completed or after such completion.

The fluid supply to the lower region of the chamber may be arranged to assist in the discharge of the products in the chamber when the closure means allows the contents of the chamber to pass out of the lower region of the chamber.

According to another aspect of the present invention, comminuting apparatus includes a chamber in which material to be comminuted is capable of being located, liquid supply means arranged to at least partially fill the chamber with liquid, and comminuting means rotatable about an axis extending across the chamber. By making the comminuting means rotatable about an axis extending across the chamber an effective comminuting action may be provided and material may not tend to rest on the pivotal axis of the comminuting means.

According to a further aspect of the present invention, a method of comminuting material comprises locating the material in a chamber, at least partially filling the chamber with liquid, causing comminuting means to rotate prior to allowing the products in the chamber to be discharged therefrom.

The present invention includes any combination of the above specified features.

The invention may be carried into practice in various ways, but one embodiment will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a side view of a comminuting machine; Figure 2 is a front view of the machine shown in Figure 1; Figure 3 is a scrap section showing part of a rotatable cutter and a stationary cutter used in the machine shown in Figures 1 and 2, Figure 4 is a plan view showing the mounting of the rotatable cutter shaft on the machine, and Figure 5 is a diagram showing the sequence of operation of various of two parts shown in Figures 1 to 4 in any one comminuting cycle.

As shown in Figures 1 and 2, the machine includes a comminuting chamber 10 into which paper based bedpans or bottles containing solids or liquids can be inserted through the top by opening a lid 12. A rotatable cutter 14 (shown in Figure 3) extends across the chamber and is driven by a motor 16 connected to a shaft 18 of the cutter by a drive belt (not shown). A trap 20 is located immediately below the chamber and is in communication therewith via circular openings extending parallel with the cutter across the complete width of the chamber The bottom of the trap 20 is connected to a drain outlet 22 via a passage 24 and a discharge valve 26.A water pump 28 which receives its supply from a tank (not shown) mounted on the machine is able to supply water selectively to the passage 24 via a pipe 30 and to a spray nozzle 32 located on the underside of the lid 12 via a pipe extending through an operating arm 34 of the lid.

A comminuting or maceration cycle will now be described.

The lid 12 is pivoted about an axis 36 to an open position to allow the paper based bedpans or bottles to be inserted into the chamber 10. Typically, four bedpans or four bottles may be comminuted in any one cycle.

The lid is then pivoted back to the position shown. On actuation of a start button 38 mounted on the end of the operating arm 34 facing the operator the comminuting cycle commences.

A locking arm 40 connected to the operating arm in the region of the axis 36 cooperates with an electro magnetic lock 42 located remote from axis 36, which lock 42 is immediately actuated to hold the lid in the closed position. As shown in Figure 5, the lid remains locked for almost the complete duration of the cycle. In addition to the electro magnetic lock 42, a mechanical lock (not shown) is provided on the operating arm 34 in the region of the start button 38.

After 1.5 seconds the pump 28 is operated and one of a pair of solenoid valves 44 (shown in Figure 2) permits water to be fed to the trap via the passage 24 (the discharge valve 26 being closed at this time). After 5 seconds, the other one of the solenoid valves 44 allows water to be fed to the spray nozzle 32 which showers the products from above with water.

The solenoid valves stop the flow of water to the spray nozzle 32 and to the trap 20, 15 and 20 seconds into the cycle respectively, when the chamber is partially filled with water.

After 22 seconds the motor 16 starts up and the cutter 14 rotates. As shown in Figure 3, the cutter 14 includes a plurality of blades 46 which rotate in an anticlockwise direction to carry the paper based products down and past a number of stationary blades 48 mounted on the inner wall of the chamber.

The blade 46 includes a cutting edge 50 facing their direction of travel and a further cutting edge 52 at their tips. The action of the blades 46 and 48 serves to quickly comminute or macerate the paper based products and any solid waste they may contain. As the products are highly floatable when they are not being impinged by the blades they tend to float quickly to the upper region of the water level, which is arranged to be around the bottom of the blades in the upwardly extending position.

The maceration or comminution of the products is substantially complete after 33 seconds of cutter operation, but the cutter 14 remains rotating. At that time, (55 seconds after the cycle has started), the drain outlet or trap discharge 22 is opened and simultaneously the solenoid valves 44 feed water to the spray nozzle 32 and the passage 24. The water supplied to the passage 24 is directed towards the drain outlet 22, and as the drain outlet is now open this water serves to push the water in the trap through the outlet 22 towards the drain. The water and comminuted products then pass through the openings in the bottom of the chamber, through the trap and out to the drain. The water from the spray nozzle washes down the inside of the lid and chamber.

The motor is stopped 85 seconds after the commencement of the cycle, and after 85 seconds so is the flow of water being fed to the drain outlet. After 105 seconds the pump 28 and supply of water to the spray nozzle are stopped and the drain outlet closed. Some 8 seconds later the electro mechanical lock 42 is released and 7 seconds later the machine is ready to repeat the cycle.

The blades 46 are arranged in two helixes 180 apart from each other, with six blades being included in each helix and extending across the chamber.

The period required for the maceration of the product is approximately 33 seconds, which is considerably less than the period required in prior machines of around two minutes. The remainder of the time after maceration is effectively used to clean the inside of the chamber and trap.

When the lid is closed, the chamber is sealed around the lid. However, as water enters the chamber, air is vented via a "P" trap into the main drain.

Claims

1. Comminuting apparatus including a comminuting chamber, liquid supply means arranged to at least partially fill the chamber with liquid, and rotatable comminuting means located in the chamber, the apparatus further including closure means selectively operable to prevent or allow the contents of the chamber to pass out of a lower region of the chamber.

2. Comminuting apparatus as claimed in Claim 1 in which the rotatable comminuting means are capable of rotating whilst the closure means prevent the contents of the chamber from passing out of the lower region of the chamber.

3. Comminuting apparatus as claimed in Claim 1 or 2 in which the rotatable comminuting means are capable of being stationary when the closure means allow the contents of the chamber to pass out of the lower region of the chamber.

4. Comminuting apparatus as claimed in any precedingclaim in which the closure means are operable automatically.

5. Comminuting apparatus as claimed in any preceding claim in which the rotational axis of the comminuting means extends across the chamber.

6. Comminuting apparatus as claimed in Claim 5 in which the rotational axis of the comminuting means is substantially horizontal.

7. Comminuting apparatus as claimed in any preceding claim in which the rotatable comminuting means includes a plurality of comminuting members.

8. Comminuting apparatus as claimed in Claim 7 in which the comminuting members are arranged substantially in a helix.

9. Comminuting apparatus as claimed in Claim 8 in which the comminuting members are arranged in two substantially helical configurations offset approximately 1800 from each other.

10. Comminuting apparatus as claimed in any preceding claim in which the outlet of the chamber comprises an opening which is slightly smaller than the products which are to be comminuted by the apparatus.

11. Comminuting apparatus as claimed in any preceding claim in which fluid is arranged to be supplied to the chamber from an upper region of the chamber.

12. Comminuting apparatus as claimed in any preceding claim in which fluid is arranged to be supplied to the chamber from a lower region of the chamber.

13. Comminuting apparatus as claimed in any preceding claim in which fluid is arranged to be supplied to the chamber before the comminuting means are arranged to rotate.

14. Comminuting apparatus as claimed in any preceding claim in which fluid is arranged to be supplied to the chamber, and the supply of that fluid is arranged to cease prior to rotation of the comminuting means.

15. Comminuting apparatus as claimed in any of Claims 1 to 13 in which fluid is arranged to be supplied to the chamber, and the supply of that fluid is arranged to cease prior to comminution of the material achieved by rotation of the comminuting means having been completed.

16. Apparatus as claimed in any of Claims 11 to 15 in which fluid is arranged to be supplied to the chamber again before comminution has been completed.

17. Comminution apparatus as claimed in any of Claims 11 to 15 in which the fluid supply to the chamber is arranged to commence again after completion of comminution.

18. Comminution apparatus including a comminuting chamber, liquid supply means arranged to at least partially fill the chamber with liquid, and comminuting means rotatable about an axis extending across the chamber.

19. Comminuting apparatus as claimed in Claim 18, including any of the features claimed in Claims 1 to 4 or 6 to 17.

20. Comminuting apparatus substantially as herein described with reference to, and as shown in any of Figures 1 to 5 of the accompanying drawings.

21. A method of comminuting material comprising locating material to be comminuted in a chamber, at least partially filling the chamber with liquid, and causing comminuting means to rotate prior to allowing the contents of the chamber to be discharged therefrom.

22. A method of comminuting material as claimed in Claim 21 comprising locating the material in the chamber prior to partially filling the chamber with liquid.

23. A method of comminuting material according to Claim 21 or 22 comprising discharging the products from the chamber whilst the comminuting means are stationary.

24. A method of comminuting material as claimed in any of Claims 21 to 23 comprising supplying liquid to the chamber from an upper region of the chamber.

25. A method of comminuting material as claimed in any of Claims 21 to 24 comprising supplying liquid to the chamber from a lower region of the chamber.

26. A method of comminuting material as claimed in any of Claims 21 to 25 comprising ceasing the supply of liquid to the chamber prior to commencing comminution.

27. A method of comminuting material as claimed in any of Claims 21 to 25 comprising ceasing the supply of liquid to the chamber prior to completion of comminution.

28. A method of comminuting material as claimed in any of Claims 21 to 27 comprising recommencing the supply of liquid to the chamber before comminution has been completed.

29. A method of comminuting material as claimed in any of Claims 21 to 26 comprising recommencing the supply of liquid to the chamber after comminution has been completed.

30. A method of comminuting material substantially as herein described with reference to, and as shown in any of Figures 1 to 5 of the accompanying drawings.

31. A method of comminuting material as claimed in any of Claims 21 to 30 using comminuting apparatus as claimed in any of Claims 1 to 20.