EP3394356B1

EP3394356B1 - 2.5 litres water saver p-trap water closet (w.c.)

Info

Publication number: EP3394356B1
Application number: EP16716311.2A
Authority: EP
Inventors: Somchai Wongaroon
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-12-25
Filing date: 2016-01-13
Publication date: 2019-10-30
Anticipated expiration: 2036-01-13
Also published as: WO2017111709A1; EP3394356A1

Description

TECHNICAL FIELD

Ceramic Engineering and Applied Physics.
The invention relates to a P-trap water closet according to the preamble of claim 1.

BACKGROUND ART

The existing 4.5 Litres Gravity fed Water Closet (W.C.) consists of a Pan and Cistern. The Cistern can be mounted directly on to the Pan (Close-coupled) or fixed to the wall (Low level) above the Pan. Water is stored inside the Cistern until discharged manually by handle or push button. The water will fall by gravity into the Pan rim where it is directed through holes in the base of the rim on to the inside face of the Pan bowl. Water will continue to run down the Pan bowl and into the sump at the base of the Pan. This action will clean the inside of the Pan bowl washing off any waste deposits. The cleaning water will run into the Pan sump creating an overflow action at the rear section of the Pan trap-way. The pressure and velocity of the water in the Pan sump created by gravity is enough to clear the sump of all waste deposits and transport to the external pipe-work drains supplied by local water authorities. Flushing regulations of the W.C. are legislated and controlled by the national standards prevailing (eg. BS, EN, SS, TIS, etc).
The existing ceramic design and technology of the Pan restricts the volume of water required per full flush to around 4.5 Litres minimum. The invention objective is designed to reduce the volume of water required per full flush to 2.5 Litres. The new design is based on the existing gravity fed water system, using no external energy source such as pump, air pressure, vacuum etc. The new design will comply fully with national standards prevailing world wide.
The big reduction in water use will provide many benefits including:

Reduced water cost for the consumer.
Reduced services and operating cost for the local water authority.
Preserve a Natural Resource worldwide for future generations.

The outside physical shape and operation of the W.C. will not change. Also,
The Cistern fittings will not change thus maintaining well proven long term reliability. To achieve the objective, the present invention is centred around three internal areas of the W.C.
JP H06 287990 A discloses a siphon type flush toilet bowl having a trap drain passage formed by mutually connecting a rising part, a down part, and a horizontal part, the section of the trap drain passage is extended from the down part toward the horizontal part. The sections of the down part and the horizontal part are formed into circular and horizontally long forms, respectively, and the short diameter of the horizontal part is set to substantially the same as the diameter of the down part.
This document is considered to represent the closest prior art.
WO 03/060244 A1 , discloses a toilet that enables the flushing of feces and urine using only a small amount of flushing water, e.g., 2.3 liters. The toilet comprises a flush lever disposed inside a water supply tank, the flush lever comprises a weight containing part connected to a hinge axis extending to both sides of the water supply tank at the center part of the weight containing part like a seesaw such that a rotary weight disposed inside the weight containing part can freely move to right and left, a flush handle exposed to the outside of the water supply tank and fixed and joined to one end of the weight containing part, and a connecting part fixed and joined to the other part such that flapper assembly and the blocking means for discharge conduit engage with the operation of the flush handle.

OBJECTIVE OF NEW DESIGN ATTRIBUTION

The overall objective is to reduce the amount of water required for a gravity fed Water Closet (W.C.) full flush from around 4.5 Litres to 2.5 Litres.
This objective is achieved by means of a P-trap water closet according to claim 1.
The invention required new design in three internal areas of the W.C. as follows:

1) Sump and Trap-way.

New design of sump and trap-way is based on the theory of water flow in pipes. It is important to create the correct carrying and self-cleaning velocities in the trap-way. It is also important to create the correct water agitation in the sump. The design of the sump and trap-way is paramount in achieving the correct velocity and water agitation to remove all waste matter from the Pan according to international standards. This can only be achieved by designing the optimum size and shape of the sump and trap-way specifically for the 2.5 Litres flushing.

2) Water distribution inside rim.

To achieve the 2.5 Litres flushing it is important to provide the correct water flow pattern to the sump and trap-way and to clean the inner walls of the Pan bowl according to International Standards. The water flow pattern is created by the size, shape and angle of the water distribution holes in the base of the Pan rim. The ultimate size, shape and angle of the holes in the Pan rim is so variable that it is impossible to calculate. The final most efficient holes pattern was determined by 25 years of ceramic sanitaryware manufacturing experience and 2 years of laboratory and quality assurance testing.

3) Cistern

To achieve a 2.5 Litres flushing, it is important to provide the correct water pressure to the rim. Water pressure in the rim will dictate the velocity of water through the holes pattern and cleaning efficiency of the Pan.
Because water pressure at the rim is controlled by water height in the cistern it is important to obtain optimum height from 2.5 Litres of water. To achieve this with the much reduced water volume of 2.5 Litres, it is necessary to slim down the width and depth of the existing cistern. This will be the only visible sign outside the Pan to suggest that the W.C. may be a low volume flush.

Please Note:

All three areas of present invention play a definitive roll in the overall plan to meet the objective. Many combinations of present invention in the three areas have been tested over a two year period. The final optimum result has been based mainly on live trials. It is therefore impossible to show specific calculations of the ultimate conclusion.

BRIEF DESCRIPTION OF DRAWING

FIGURE 1 - To illustrate the present invented slim cistern and compare with conventional design.
FIGURE 2 - To illustrate the present invented water distribution holes pattern in pan rim base.
FIGURE 3 - To illustrate the present invented trap-way and compare with the conventional design.
FIGURE 4 - To illustrate the structure of present invented Water Closet and water movement.

DISCLOSURE OF INVENTION

Ref Figure 1 Design detail of sump and trap-way

The new design for sump and trap-way 6 is based on shape and size to give the correct water carrying velocity and water cleaning velocity. It is also designed to minimise resistance to moving waste matter. The shape of the sump creates the water turbulence and correct carrying velocity push between the Pan bowl and the trap-way 6. In the new design the shape of the trap-way 6 is round, instead of the predominant squarer shape of the conventional Pan trap-way 6. The new design trap-way has a smooth transition from 62.5mm dia. sump side 10 to 70mm dia. exit side 12. This was found to provide the correct carrying and cleaning velocity to transfer all waste matter to the external services when working in combination with the other two new design areas (Distribution holes and Cistern 8).
The trap-way 6 is also fully glazed inside to minimise wall resistance to the conveyed waste.

Ref Figure 2 Design detail of water distribution holes pattern in base of pan rim.

The new design for the water distribution holes 14, 20 and 22 is based on know-how and many trials over months of research. The design detail is centred around the hole size, shape, position and angle. Holes are punched by hand using a precision gauge while clay is in the green state.
The hole pattern will direct water to efficiently clean the Pan bowl and provide the water agitation push in the sump to create the initial carrying velocity to convey the waste matter.

Ref Figure 3 Design detail of water cistern

The new design of the water cistern 8 is very similar to the existing conventional water cistern.
This is intentional so that existing cistern fittings can be used to retain the established long term operating reliability and easy to obtain spares.
The height of the water level inside the new cistern will determine the pressure inside the rim 2.
Tests have shown that the water height for 2.5 Litres is similar to the water height for 4.5 and 6.0 Litres. It is therefore necessary to reduce the volume inside the new Cistern so that 2.5 Litres attain the same height as 4.5 or 6.0 Litres. The only way to attain this height and maintain existing production processes is to reduce the width and depth of the new cistern.
The slimmer cistern will be the only difference in external appearance of the 2.5 Litre W.C.

Ref Figure 4 Design detail of Water Closet structure and water movement

The new design of 2.5 Litres Water Saver P-Trap Water Closet (WC.) 1 is very similar externally to the existing conventional
Water Closet 1, the only slight difference being the slimmer water cistern 8.
This is intentional to retain the general aesthetics of the existing water closet 1.
All new design is on the inside of the water closet 1 as explained in detail with pictures above.
Water flow is from the cistern 8. Static height of water in the cistern 8 provides the pressure in the Pan rim 2. Water is directed out of rim 2 via holes in the base 4 of the rim 2. The hole pattern will dictate the cleaning efficiency on the bowl sides and the rate of directed turbulence in the sump. The created water carrying velocity in the sump and trap-way will convey the waste matter to external services. During this operation, the correct water cleaning velocity will clean the sump and trap-way 6. All operations will comply with International standards.

ASSURANCE OF EFFECTIVE PERFORMANCE TESTING

All testing was carried out "In house" in a laboratory and Quality Assurance environment.
Throughout the development process all personnel were mindful of attaining International flushing standards including BS, EN, SS, TIS etc, both in physical attribution and working performance (See testing report in attached document). All post development tests of the 2.5 Litres Water Saver P-Trap Water Closet (WC.) have complied with International Standards.

PERFORMANCE TESTING REPORT

FUNCTION TEST		RESULT					STANDARD
							TIS 792 : 2554	EX997 : 2012		SS 574 : 2012
							TIS 792 : 2554	CLASS 1	CLASS 2	SS 574 : 2012
Tissue Paper (pcs.) / Full Flush		/	/	/	/	/	7(110x750)	12(100x140)	-	12(100x160)
Tissue Paper (pcs.) / HalfFlush		/	/	/	/	/	-	-	6(100x140)	1(4 joined sheets)
Ball Dia.Ø (mm.) Ø 43,50		/	/	/	/	/	-	-	-	Ø43
50 small plastic balls left.							-	≥ 85%	-	-
Ink Test							Clean	-	-	-
Towel Discharge		/	/	/	/	/	-	-	-	-
Sawdust (mm²)		/	/	/	/	/	-	≤ 5000	≤ 5000	≤ 5000
Over Splashing		/	/	/	/	/	-	Small Drop	-	-
Color Contamination (MIB)		/	/	/			Great or Equal	-	-	Great or Equal
Dye Contamination	Full Flush						-	-	≤ 1%	-
Dye Contamination	Half Flush						-	-	≤ 6%	-
Test Rig For After Flush Volume							-	4 Test	4 Test	-
Test Rig For After Flush Volume							-	Speciment	Speciment	-
After Flush Volume							-	≥ 2.5 or 2.8	40% or Full	-
After Flush Volume							-	Liter	Flush	-
Time Discharge (sec.)							≤ 10	-	-	-

BEST MODE FOR CARRYING OUT THE INVENTION

Refer to full details described on Disclosure of Invention section.

Claims

P-trap water closet (1) comprising:
[a] a pan with
[i] a rim (2) with a base (4) having a water distribution hole pattern extending adjacently to the inner hole curve of the rim (2) and

[ii] a trap-way (6), said trap-way being round and fully glazed with smooth transition, and

[b] a cistern (8) of 2,5 Litres capacity,
characterized in that

[c] said trap-way (6) has a narrowed bend with 62.50mm diameter at sump side (10) and 70.00 mm diameter at exit side (12), such that the water volume and natural water resistance are reduced at the least level whereas the water volume of 2.5 Litres still provides a smooth passage of waste to maintain carrying and cleaning velocity of the water, in that

[d] said water distribution pattern of said rim has
[i] 5 first circle holes (14) of 5 mm diameter, each one of said 5 first circle holes (14) being positioned at the frontal end (16) of said rim and oriented at 28 degrees of bending angle relative to the top plane (18) of the rim, and said 5 first circle holes (14) being symmetrically arranged relative to the central vertical plane of the pan (1),

[ii] 2 second elongated holes (20), symmetrically arranged relative to said central plane, said second elongated holes (20) being 85 mm long and having a 15 mm of diameter, said second elongated holes (20) being arranged the one at the left side and the other one at the right side of the pan (1) and the edge of each of said second elongated holes (20) being the closest to said frontal end (16) being distanced 35 mm in the direction of said central vertical plane, and

[iii] 22 third circle holes (22) of 5 mm diameter, distributed along said rim (2) between said 2 second elongated holes (20), said third circle holes (22) being positioned at 28 degrees of bending angle relative to said top plane (18) of the rim (2) and with a proximity of 20 mm from hole to adjacent hole.