GB2234268A

GB2234268A - Drain cleaning apparatus

Info

Publication number: GB2234268A
Application number: GB9014665A
Authority: GB
Inventors: James Hutton
Original assignee: Hitech Equipment Ltd
Current assignee: Hitech Equipment Ltd
Priority date: 1989-07-27
Filing date: 1990-07-02
Publication date: 1991-01-30
Also published as: GB9014665D0; GB8917169D0

Abstract

Drain cleaning apparatus is described which comprises a clean tank (4) for holding a fluid (6) and a first transfer means (15) for transferring the fluid (6) from the clean tank (4) into a drain to be cleaned. There is also a second transfer means (5) for transferring the fluid and waste material from the drain to a waste tank (3), a third transfer means (12, 20) to transfer the fluid (8) from the waste tank (3) to the clean tank (4) and filter means (11, 10, 13) to prevent substantially all the waste material (7, 8) from entering the clean tank (4) from the waste tank (6). Preferably the filter means comprises a baffle filter located in the waste tank, the baffle filler comprising a first sheet of material (10) extending upwards from the base of the waste tank and a second sheet of material (11) extending downwards from the top of the waste tank so that the sheets overlap but do not extend across the full height of the waste tank, the sheets being spaced from each other and extending across the width of the waste tank. The apparatus is suitably mounted on a vehicle. <IMAGE>

Description

Drain Cleaning Apparatus The invention relates to drain cleaning apparatus.

Conventionally, when cleaning drains it is common to inject water into the drain at a high pressure in order to dislodge waste material from the sides of the drain and the water along with the waste material is then sucked out of the drain and into a waste storage tank.

However, it is necessary to have a supply of water to inject into the drain. One attempt at overcoming this problem at locations without a water supply has been to provide a twin tank jet and vacuum truck. This apparatus comprises two separate tanks, the first tank holds water to be injected into the drain and the second tank is for the collection of the water and waste material from the drain. However, as the second tank holds both the water and the waste material it becomes full relatively quickly. With the current apparatus available this generally only takes about 20 to 30 minutes. This leads to an inefficient and expensive method of cleaning drains as the first tank has to be refilled with water as soon as it is empty and the second tank needs to be emptied of the waste when it is full.

In accordance with one aspect of the present invention, filtering apparatus comprises a vehicle, a waste tank mounted on the vehicle for holding a fluid, the waste tank having an inlet, an outlet and a baffle filter located between the inlet and the outlet to filter fluid entering the waste tank through the inlet before the fluid is discharged from the waste tank through the outlet; and wherein the baffle filter comprises a first sheet of material extending upwards from the base of the waste tank and a second sheet of material extending downwards from the top of the waste tank so that the sheets overlap but do not extend across the full height of the waste tank, the sheets being spaced from each other and extending across the width of the waste tank.

In accordance with another aspect of the present invention, drain cleaning apparatus comprises a clean tank for holding a fluid, first transfer means for transferring the fluid from the clean tank into a drain to be cleaned, second transfer means for transferring the fluid and waste material from the drain to a waste tank, a third transfer means to transfer the fluid from the waste tank to the clean tank and filter means to prevent substantially all the waste material from entering the clean tank from the waste tank.

The invention enables the fluid to be continuously recycled through the apparatus until the waste tank is full of waste material. In addition, extracting the fluid from the waste tank means that only the waste material is stored in the waste tank.

In the preferred embodiment, the filter means comprises a baffle filter located in the waste tank which prevents substantially all the waste material from entering the third transfer means. Typically, the filter means also comprises a filter between the third transfer means and the clean tank and preferably this is a self-cleaning filter.

Preferably, the baffle filter comprises a first plate attached to the base of the waste tank so that there is a gap between the top of the first plate and the top of the waste tank and a second plate attached to the top of the waste tank so that there is a gap between the bottom of the second plate and the bottom of the waste tank.

Preferably, the top of the first plate extends above the bottom of the second plate so that the plates partially overlap but are spaced from each other.

Typically, the first plate is closer to the entrance of the second transfer means into the waste tank than the second plate. Hence, solid waste material which is heavier than water is retained by the first plate and waste material which is lighter than water, such as oil, is retained by the second plate when the water level in the waste tank is higher than the top of the first plate.

Typically, each transfer means comprises a pump to transfer the fluid. Preferably, a vacuum of substantially 12 to 18 centimetres of mercury is created in the waste tank and the third transfer means is capable of creating a vacuum of approximately 75 centimetres to enable the fluid to be transferred from the waste tank to the clean tank.

Preferably, the apparatus also comprises means to maintain the fluid level in the waste tank above a predetermined minimum level. Typically, there is also means to maintain the fluid level in the waste tank below a predetermined maximum level.

Typically, the apparatus is designed to be used with water as the fluid.

An example of drain cleaning apparatus according to the invention will now be described with reference to the accompanying drawings, in which: Fig. 1 is a schematic diagram of drain cleaning apparatus; and, Fig. 2 is a schematic diagram of a self-cleaning filter for use in the apparatus shown in Fig. 1.

Fig. 1 shows a container 1 which has two tanks 3, 4.

The tanks 3, 4 are separated by a partitioning wall 2 and could have capacities of approximately 1,850 gallons and 350 gallons respectively. The tank 3 has an inlet 5 to enable water 6 and waste materials 7, 8 to enter the tank 3 and an outlet 9 which is connected to a vacuum pump (not shown), such as a Roots blower in order to create a vacuum within the tank 3 so that the water 6 and the waste materials 7, 8 may be sucked from a drain into the tank 3 through the inlet 5.

The tank 3 also comprises a baffle filter which comprises two plates 10, 11 and another outlet 12 situated between the partitioning wall 2 and the baffle plate 10. The baffle plate 10 is situated on the bottom of the tank so that there is a gap between the top of the plate 10 and the top of the container 1 and the baffle plate 11 is positioned on the top side of the container 1 so that there is a gap between the bottom of the plate 11 and the bottom of the container 1, and so that the plates 10, 11 partially overlap, as shown in Fig. 1.

The outlet 12 is connected via a vacuum pump to a filter 13. Typically, the vacuum pump is a centrifugal pump'which pumps water from the outlet 12 at a rate of approximately 60 to 65 gallons per minute. The filter 13 could be a conventional filter. However, preferably it is a self-cleaning filter as shown in Fig. 2.

In Fig. 2 the self-cleaning filter 13 comprises a main tank 25 having a number of filter elements 21, an upper section 22 and a lower section 23. The tank 25 has two inlets 24, 26 which enter the tank 25 at the lower section 23 and the upper section 22, respectively.

There are also two outlets 20, 27 at the top and the bottom of the tank 25, respectively. The inlets 24, 26 and the outlets 20, 27 have valves 28, 29, 30, 31, respectively, which enable each inlet or outlet to be closed or opened.

In use, the valves 29, 31 of the filter 13 are normally closed and the valves 28, 30 are open. This allows water from the pump to pass along conduit 32, through the valve 28 and the inlet 24 and into the lower section 23 of the tank 25. As the valve 31 is closed the water is forced up through the filter elements 21 into the upper section 22. The filtered water in the upper section 22 can then pass through the valve 30 and the outlet 20 to the tank 4.

When the filter elements 21 become clogged the pressure difference in the tank 25 between the lower section 23 and the upper section 22 will increase and the flow of water to the upper section 22 will decrease. The filter elements 21 can then be cleaned by closing valves 28, 30 and opening valves 29, 31. This causes water from the pump to be directed from the conduit 32 into the conduit 33 and water enters the tank 25 through the inlet 26. The water passes down the filter elements 21, removing dirt and sediment from them and flows out of the lower section 23 through the outlet 27, flushing the dirt and sediment removed from the filter elements with it. The outlet 27 is connected to the inlet 5 of the tank 3 so that the dirt and sediment is deposited in the tank 3.After the filter 13 has been cleaned, valves 29, 31 are closed and valves 28, 30 are opened again so that water from the pump may be filtered and passed into the tank 4. A pressure monitor could monitor the pressure difference between the upper and lower sections 22, 23 and could cause an indicator (not shown) to indicate to an operator when the filter 13 needs cleaned and/or to automatically activate the valves 28, 29, 30, 31 to clean the filter elements 21.

As the volume of waste materials 7, 8 in the tank 3 increases, the volume of water which can be held in the tank 3 decreases correspondingly. Hence, an outlet 17 may be opened to decrease the water level in the tank 3 as and when necessary. As the water in the vicinity of the outlet 17 contains very little waste material, if any, this overflow water may be pumped directly down the drain being cleaned without transferring any substantial waste material back to the drain.

The tank 3 has a one-way valve 18 operated by a float 14 to allow fluid to flow from the tank 4 to the tank 3. If the water level in the tank 3 drops below a certain level the float 14 opens the one-way valve 18 which causes water to be jetted through the one-way valve 18 from the tank 4 to increase the level of the water in the tank 3.

The tank 4 also has an outlet 15 which enables water to be taken from the tank 4 and pumped down a drain via a hose (not shown) in order to clean the drain.

The container 1 will generally be mounted on the back of a truck (not shown) so that the apparatus may be easily transported to a drain which is to be cleaned.

The engine of the truck may provide the power necessary for the vacuum pumps or there may be a separate generator mounted adjacent to the container on the truck.

In use, the truck on which the container is mounted is driven to a drain which is to be cleaned. At the beginning of the drain cleaning operation the tanks 3, 4 are filled with water to the levels shown in Fig. 1.

The hose which is connected to the outlet 15 of the tank 4 is then inserted into the drain and the return hose which is connected to the inlet 5 of the tank 3 is inserted into the drain. The pumps are then switched on and water from the tank 4 is extracted from the tank 4 through the outlet 15 and forced at high pressure into the drain in order to dislodge waste material from the inside of the drain. Because of the vacuum which is created in the tank 3 by the vacuum pump connected to the outlet 9, the water 6 which has been expelled from the tank 4 into the drain to dislodge the waste material is then sucked along with the waste material through the return hose and the inlet 5 into the tank 3. Typically, the vacuum in the tank 3 is between about 12 cm of mercury and 18 cm of mercury.

At the same time, water is drawn from the tank 3 and passed through the water filter 13 to replenish the water taken from the tank 4. If the water level in the tank 3 drops below a predetermined level the float 14 opens the valve 18 to allow water to pass from the tank 4 into the tank 3 to raise the water level in the tank 3.

As the water 6 and the waste materials 7, 8 pass through the inlet 5 of the tank 3, a baffle 16 directs the incoming water 6 and the waste materials 7, 8 away from the baffle filter. As the water 6 and the waste materials 7, 8 enter the tank 3 the waste materials 7 which are denser than water form a sediment, as shown in Fig. 1, which is contained in the tank 3 by the baffle filter plate 10. Waste materials 8 which are lighter than water float on the surface of the water 6 and these are retained in the tank 3 by the baffle filter plate 11 so that substantially all of the waste materials 7, 8 are prevented from passing through the baffle filter and entering the outlet 12 which supplies the water 6 to the tank 4 via the water filter 13.

However, not all of the waste materials 7, 8 will separate out of the water 6 and so the water filter 13 is present to filter out the waste materials 7, 8 which are still present in the water 6 when it enters the outlet 12.

By using this apparatus it is possible to continuously recycle the water used to dislodge the waste materials from the drain until the waste material 7 which forms the sediment reaches the top or near the top of the baffle filter plate 10. This means that the tank 3 contains nearly all waste material 7, 8 and has very little water content. This increases the waste material capacity of the tank 3 over conventional drain cleaning apparatus.

As the tank 3 fills with the waste materials 7, 8 the volume of water which can be contained in the tank 3 decreases. Hence, the surplus water may be expelled from the tank 3 via an overflow mechanism (not shown) as is necessary.

By using apparatus of this type it would be possible to continuously carry out a drain cleaning operation for half a day or even a whole day depending on the amount of waste material present in the drain. This provides distinct advantages in efficiency and cost over the prior art apparatus where it was only possible to continuously clean a drain for about twenty minutes to thirty minutes at a single time.

Modifications and improvements may be incorporated without departing from the scope of the invention.

Claims

1. Filtering apparatus comprising a clean tank for holding a fluid, first transfer means for transferring the fluid from the clean tank into a drain to be cleaned, second transfer means for transferring the fluid and waste material from the drain to a waste tank, a third transfer means to transfer the fluid from the waste tank to the clean tank and filter means to prevent substantially all the waste material from entering the clean tank from the waste tank.

2. Apparatus according to Claim 1, wherein the filter means comprises a baffle filter located in the waste tank, the baffle filter comprising a first sheet of material extending upwards from the base of the waste tank and a second sheet of material extending downwards from the top of the waste tank so that the sheets overlap but do not extend across the full height of the waste tank, the sheets being spaced from each other and extending across the width of the waste tank.

3. Apparatus according to Claim 2, wherein the first sheet of material is closer to the inlet than the second sheet of material.

4. Apparatus according to any of the preceding Claims, wherein the apparatus further comprises means to maintain the fluid level in the second tank above a predetermined minimum level.

5. Apparatus according to any of the preceding Claims, wherein the apparatus further comprises means to maintain the fluid level in the first tank below a predetermined maximum level.

6. Filtering apparatus comprising a vehicle, a waste tank mounted on the vehicle for holding a fluid, the waste tank having an inlet, an outlet and a baffle filter located between the inlet and the outlet to filter fluid entering the waste tank through the inlet before the fluid is discharged from the waste tank through the outlet; and wherein the baffle filter comprises a first sheet of material extending upwards from the base of the waste tank and a second sheet of material extending downwards from the top of the waste tank so that the sheets overlap but do not extend across the full height of the waste tank, the sheets being spaced from each other and extending across the width of the waste tank.

7. Filtering apparatus according to Claim 6, wherein the apparatus further comprises means to maintain the fluid level in the first tank above a predetermined minimum level.

8. Filtering apparatus according to Claim 6 or Claim 7, wherein the apparatus further comprises means to maintain the fluid level in the first tank below a predetermined maximum level.