GB2514394A

GB2514394A - Macerator apparatus and method

Info

Publication number: GB2514394A
Application number: GB1309264.8A
Authority: GB
Inventors: Nigel R C Shepherd
Original assignee: Haigh Engineering Co Ltd
Current assignee: Haigh Engineering Co Ltd
Priority date: 2013-05-23
Filing date: 2013-05-23
Publication date: 2014-11-26
Anticipated expiration: 2033-05-23
Also published as: GB2514394B; GB201309264D0

Abstract

Apparatus and method, in which a macerator 1 features a chamber 2, a drain 5, a seal 4 and a control means 11 which can vary the supply of water, such as by valves 12, to one or moreÂ components of the drain 5, the chamber 2 and the seal 4, variation in accordance withÂ point in time of a maceration cycle. In particular, supply to the drain 5, may be restricted in initial and final periods of the maceration cycle, and supply to the chamber 2 and seal 4, may be increased in a middle period of the maceration cycle. In this manner, the overall amount of water used throughout the cycle may be reduced.

Description

Macerator Apparatus and Method The present invention relates to macerators, which process waste products by reducing such waste products into a slurry that can then more readily flow through drainage conduits.

In this connection, within a macerator that disposes of pulp products, water is pumped to a chamber where the pulp products are macerated to form a slurry which passes into a drain. Water is also pumped to a mechanical seal to ensure the seal is lubricated and also to the drain at the outlet of the maccratot The latter ensures the pump slurry is sufficiently diluted to pass through the drain pipes.

Whilst this arrangement offers advantages in terms of ensuring movement of the slurry through the drain pipes, it relies on a relatively high consumption of water.

In our patent EP1348816, we describe a macerator arrangement where water supply to the macerator is switched off during part of the macerator disposal cycle. Whilst this is an improvement in terms of reducing water consumption, it is an object of the present invention to seek to provide an improved apparatus and method, which further addresses problems associated with such known arrangements.

According to the present invention there is provided macerator apparatus comprising:-a chamber for macerating waste product; a drain for draining macerated waste product from said chambe a macorator seal for sealing the macerator chamber; and control means for varying the supply of water to the drain and one or more of the chamber and seal during a maceration cycle of the apparatus, the supply of water being varied according to the point in time in the maceration cycle of the apparatus.

In this way, the apparatus can provide an effective manner of supplying water which enhances the macerating process and uses the water most effectively.

Preferably, the apparatus fhrther comprises one or more valves for controlling the water supply. These can be provided locally at the respective components requiring the supply of waler. Alternatively, a central valve may he used to direct water supply to each of the components.

Conveniently, the control means restricts water suppiy to the drain in an initial period of the maceration cycle. The water supply to the drain can as such he turned off completely during this initial period, or may be increased gradually as the cycle progresses.

The control means may further restrict water supply to the drain in a final period of the maceration cycle. The supply may be turned off completely or gradually reduced as the cycle progresses.

Preferably, the control means increases water supply to the chamber and seal in a middle period of the maceration cycle.

The inaceration cycle preferably has a cycle time of substantially 90 to 120 seconds, an initial cycle period ending substantially from 10 to 20 seconds and a final cycle period starting from substantially 30 to 40 seconds, a middle cycle period being between substantially 10 and 40 seconds.

Conveniently, the control means controls the water supply to the drain such that it has no water supply for between 25-34% of a maceration cycle. In this way, a significant water saving is made, without comproniising the effectiveness of the maccrating process.

Preferably, the drain water supply is located upstream of the macerator and/or seal water supplies. This allows for an arrangement where control of the water supply to the drain will impact on the water supply to the macerator and/or the seal.

According to a further aspect of the present invention there is provided a method for controlling a water supply to a macerator having a chamber for maccrating waste product, a drain for draining maccrated waste product from said chamber, and a maccrator seal for sealing the macerator chamber; the method comprising the steps;-supplying water to one or more of the chamber, drain, and seal; controlling the supply of water during a maceration cycle of the apparatus to the drain and one or more of the chamber and seal being varied according to the point in time in the maceration cycle. By way of this method, the water supply can be utilised more effectively and efficiently.

Preferably, the method further comprises restricting water supply to the drain in an initial period of the maceration cycle.

The method may conveniently further comprise restricting water supply to the drain in a fmal period of the maceration cycle.

In preferred embodiments the method fiirthcr comprises increasing the water supply to the chamber and seal in a middle period of the maceration cycle.

Prefrrably, the maccration cycle has a cycle time of substantially 90 to 120 seconds, an initial cycle period ending substantially from 10 to 20 seconds and a final cycle period starting from substantially 30 to 40 seconds, a middle cycle period being between substantially 10 and 40 seconds.

An embodiment of the present invention will now be described by way of example and with reference to the accompanying drawings, of which:-Figure 1 shows schematically apparatus according to the present invention; and Figure 2 shows time line graphs according to the present invention.

As shown in Figure 1, a macerator I has a chamber 2 into which waste products are fed for maccration. The macerator includes a lid 3, a mechanical seal 4 and a seal water inlet 10.

Macerated waste product is drained from drain outlet 5. The apparatus further includes a chamber water inlet 6, fed from a suitable water supply 7 via a conduit 13.

The water supply 7is additionally in fluid connection with the drain outlet 5 by means of conduit 8 and to the seal 4 by means of conduit 9. A controller II controls the valves 12 to distribute water to each of the chamber, seal and drain according to the time point in the maceration cycle.

In a typical known process of maceration in this kind of product, which may have a cycle time of two minutes or less, the concentration of pump slurry maxinlises between 20 seconds and 40 seconds from the initiation of the process. The concentration falls away bctween 40 seconds and the end of the cycle such that the macerator chamber and the drain pipes are effectively rinsed clean.

Whilst pulp maccation devices increasingly strive to use less water, water is still a potential wasted resource and it is important to use water as economically as possible.

In this connection, the applicants have recognised that certain advantages can be gleaned by altering and controlling the hydraulics balance between the macerator chamber, the seal feed and the drain.

For example, by increasing the water delivered to the macerator chamber and the seal at a specific part of the cycle where the concentration is at its normal maximum, the pump slurry flows move freely along the drain. This means that the drain jet can be shut off for the first part of the cycle, for example notionally for 20 seconds, and shut off after for cxample 50 seconds. This is shown graphically in Figure 2 which shows a conventional cycle compared with the "Premium cycle" of the present invention.

It will be noted that in the Premium Cycle, the flow to drain is closed until 20 seconds into the maceration cycle. It the increases to a maximum at around 25 seconds where it remains until around 40 seconds where it starts to reduce until 45 seconds when it is completely shut off The flow to the seal increases and decreases generally in line with that to the drain, although it is never completely shut off. The flow to the macerator chamber (the lid) in contrast decreases as the flow to the drain and seal increases and then increases again when the flow to the drain and seal reduces.

A central valve may be used to control the water supply to the various components, or alternatively as shown in Figure 1, suitably placed solenoid valves 12 controlled by the controller 11 may be used. From a comparison of the graphs it will be noted that the Premium Cycle uses less water overall, the area under the graphs representing the volume of water used.

In a preferred embodiment, just the valve 12 in the drain water conduit 8 can be controlled, since closing this valve will increase the flow to the chamber inlet 6 and seal inlet 10. As such, in a preferred arrangement, the water supply conduit to the drain is upstream of the water supply conduits to the macerator and the seal.

Implementing this change has two main benefits. Firstly, it prolongs the passage of pump slurry through the macerator as less water enters the macerator chamber whcn the drain jet is closed making finer particle size as a consequence.

Secondly, the water entering the macerator via the lid spray increases marginally creating a higher-pressure spray assisting the cleaning of the internal maccrator chamber when the drain jet is closed.

Thirdly, because the drain jet is only open for a limited period, for example 30 seconds over a 120 second or 90 second cycle, substantial water usage over a cycle is achieved optimising the use of water to dispose of pulp products.

This technique applies to other types of maccrating disposers including disposers for sanitary towels, disposable incontinent pads and disposable nappies.

Within the context of design, the additional water required at the drain may be provided by a separate pump or by taking a feed off the incoming water supply to the disposer subject to water regulations.

It will be understood that the above embodiments are examples of the present invention and that variants are possible within the scope of the appending claims.

For example, whilst a central valve is shown as controlling the distribution of water between the various components, individual valves may he provided locally adjacent the components which arc actuated by the control means.

The valves may he of any suitable construction, such as cleetromechanically operated solenoid valves.

The reduction and increase in water supply to the various components can he controlled very accurately and varied to optimise the performance of the apparatus in differing operating conditions and for dealing with different types of waste product.

The respective reductions and increases during the cycle time can be made gradually, for example in increments, or more quickly to completely shut off a supply if required.

Claims

Claims; 1. Macerator apparatus comprising:-a chamber for macerating waste product; a drain for draining macerated waste product from said chamber; a macerator seal for sealing the macerator chamber; and control means for varying the supply of water to the drain and one or more of the chamber and seal during a maceration cycle of the apparatus, the supply of water being varied according to the point in time in the maceration cycle of the apparatus.
2. Macerator apparatus according to claim 1, wherein the apparatus fbrther comprises one or more valves for controlling the water supply.
3. Macerator apparatus according to claim 1 or 2, wherein the control means restricts watcr supply to the drain in an initial period of the maceration cycle.
4. Macerator apparatus according to any preceding claim, wherein the control means restricts water supply to the drain in a final period of the maceration cycle.
5. Macerator apparatus according to any preceding claim, wherein the control means increases water supply to the chamber and seal in a middle period of the maceration cycle.
6. Macerator apparatus according to any preceding claim, wherein the maceration cycle has a cycle time of substantially 90 to 120 seconds, an initial cycle period ending substantially from 10 to 20 seconds and a final cycle period starting from substantially 30 to 40 seconds, a middle cycle period being between substantially 10 and 40 seconds.
7. Macerator apparatus according to any preceding claim, wherein the control means controls the water supply to the drain such that it has no water supply for between 25-34% of a maccration cycle.
8. Maccrator apparatus according to any preceding claim, wherein the drain water supply is located upstream of the macerator and/or seal watcr supplies.
9. A method for controlling a water supply to a macerator having a chamber for maccrating waste product, a drain for draining maccrated waste product from said chamber, and a maccrator sea! for sealing the macerator chamber; the method comprising the steps:-supplying water to one or more of the chamber, drain, and seal; controlling the supply of water during a niaccration cycle to the drain and one or more of the chamber and seal, the water supply being varied according to the point in time in the maceration cycle.
10. A method according to claim 9, further comprising restricting watcr supply to the drain in an initial period of the maceration cycle.
11. A method according claim 9 or 10, further comprising restricting water supply to the drain in a final period of the maceration cycle.
12. A method according to any one of claims 9 to 11, further comprising increasing the water supply to the chamber and seal in a middle period of the maceration cycle.
13. A method according to any one of claims 9 to 12, wherein the maccration cycle has a cycle time of substantially 90 to 120 seconds, an initial cycle period ending substantially from 10 to 20 seconds and a final cycle period starting from substantially 30 to 40 seconds, a middle cycle period being between substantially 10 and 40 seconds.
14. Apparatus substantially as hereinbefore described with referencc to the accompanying drawings.
15. A method substantially as hereinbefore described with reference to the accompanying drawings.