Field of the invention

This invention discloses a comprehensive device with minimum moving parts that maybe brought online in variable fluid flows to automatically create targeted process intensification including cavitation. More particularly the invention provides a device that can be incorporated or retrofitted in borewell handpumps or water pipelines or sewage waters for disinfecting water in continuous flow. Further the invention provides a method of substantially killing microbes in fluids (e.g. water) when the said device is incorporated or retrofitted in borewell handpumps or water pipelines or sewage water.

Background of the Invention

Providing cost effective devices and processes for treatment of potable/industrial water/sewage water substantially free of microbes without the addition of chemicals or disinfecting agents in large quantities continues to be a major challenge. A further challenge is to provide devices and processes that may be incorporated or retrofitted in on-line fluid flows including variable flows.

The applicant has filed a patent application "A DEVICE AND METHOD FOR ONLINE CAVITATION" application no 201621013750. The present invention is a device for disinfection of water that can be modularly incorporated / retrofitted online into fluid flows including variable fluid flows that are capable of creating targeted process intensification necessary for applications such as for substantially killing microbes in real time irrespective of the supply pressure / fluid flow rate of the liquid. The device is capable of adjusting the back pressure to control the bubble collapse in case of cavitation.

The shortcomings of the devices of the prior art have been overcome by the device of the present invention illustrated in FIG1.

The device of the prior art had two chambers where the fluid had to take two sharp right angle turn before it flowed out of the device resulting in substantial pressure drop and thus increased energy usage. In the device of the present invention the fluid flow experiences none or only one right angle turn resulting in substantial reduction in pressure drop & energy usage with concurrent enhancement in performance. Further the device of the present invention has advantage of ease of manufacture and substantial decrease in inventory due to interchangeability of parts.

Summary of the invention

The main object of the invention is to provide a device that is capable of being modularly retrofitted or built into online variable fluid flows for enhanced process intensification including cavitation for production of substantially microbe free water drawn from diverse sources including ground water/sewage plants in batch and continuous online flow systems.

Another object of the invention is to keep the process enhancement characteristic constant under variable fluid flows. This is done by keeping the fluid pressure drop across the orifice [32] constant by the up and down movement of the movable baffle [52], which variably uncovers or covers the orifice [32], due to the spring [66] pressure plus its own weight on one side and the fluid pressure on the other in real time. Yet another object of the invention is to provide the said device with substantial reduction in the number of parts as compared to the devices in the prior art.

Yet another object of the invention is to provide the said device that is simpler and cost effectively manufactured as compared to the devices disclosed in the prior art. Yet another object of the invention is to provide the said device with interchangeability of parts leading to decreased inventory for usage with a variety of pumps including centrifugal and positive displacement types by modularly replacing and/or rearranging selected components in the device. Another object of the invention is to provide the said device with a mechanism to generate variable area of cross section of the vena contracta of the orifice or orifices that can be selectively changed either manually or automatically with fluid pressure/ electrically / pneumatically/ electronically. Another object of the invention is to provide the said device with dosing points to dose fluids as appropriate.

Brief description of the drawings

FIG. 1 Cross-sectional view taken of a longitudinal section of the device of the present invention for creating targeted process intensification in fluids.

FIG. 2 Longitudinal view of the embodiment for fitting on India Mark 2 handpump. FIG 2[A] Longitudinal view of an embodiment for fitting on India Mark2 handpump with the restraining cover [100] without the requirement of holding circlip [84]

Fig 2[B] Longitudinal view of an embodiment for fitting on India Mark 2 handpump, where the bottom part [56] is threaded and screwed onto the riser pipe [98] Fig 2[C] side view of the orifice strip [33] with profiled orifices [44] FIG 3(A) Longitudinal view of the India Mark 2 handpump. FIG 3(B) Enlarged view of the Water Tank [90] of the India Mark 2 Handpump.

FIG 3(C) Enlarged longitudinal view of the Water Tank [90] of the India Mark 2 Handpump water tank with the embodiment of the device of the present invention fitted. In this the orifices [32] are closed by the movable baffle [52].. The central rod [94] of India Mark 2 handpump is not shown in the figure 3(C).

FIG 3(D) Enlarged longitudinal view of the India Mark 2 handpump bottom cylinder [120] which has the check valve and the plunger assembly of the handpump, on top of which an embodiment of the device as illustrated in FIG1 is fitted.

FIG[4] Embodiment of combined baffle plates [200,201 ], the relative movement of which, changes the profiled orifices [204] to change the area of the vena contracta. In this case the relative movement of the plates is got by bevel gear arrangement [202,203]. FIG 4[A] is side view, of the combined baffle plates [200,201 ] with the bevel gear arrangement [202,203] to change the profile of the orifices [204]. FIG 4[B] is cross-sectional view of the combined baffle plates [200,201 ] with profile orifice [204].

FIG 5[A] is side view of the device with only the combined baffle plates [200,201 ] without the movable baffle assembly [50].

FIG 5[B] is side view of the combined baffle plates [200,201 ] wherein the distance between the two sets of plates can be changed as per need in the direction of the flow.

Detailed description of the invention

The present invention comprises a central baffle assembly [50], enveloped by housing [56,58] to form a single flow through chamber, connected to inlet [80] and outlet [82] pipes for fluid flow through the device. The first portion as the inlet side [12] has an optional filter [104], plurality of baffle plates [70] in the form of flat discs, cones, concave or convex or a combination thereof, and stacked at predetermined positions with profiled orifices [42] which has a hole [1 14] for an optional rod [102] to pass through. The central baffle assembly [50] has profiled orifices [32] on the wall of the said portion of the chamber and is opened or closed by the movement of the movable baffle [52] with a hole [1 12] for the optional rod [102] to pass through. The movable baffle [52] is either loaded by its own weight or optionally by a spring [66], with its movement along the vertical axis of the chamber. With the pressure of the fluid the movable baffle [52] is pushed up to expose the profiled orifices [32]. The movable baffle [52] is balanced with fluid pressure on inlet side and spring pressure or its own weight on the other with the equalization holes [28] facilitating the movement of the fluid above the movable baffle [52]. The portion enveloped by housing [58] is coaxially fixed to the central flow through central baffle assembly [50] separated either by spacers [106] or other means like indentation to accommodate plurality of baffle plates [54], that are flat discs, cones, concave or convex or a combination thereof, and stacked at predetermined positions, wherein the baffle plates when stacked have their orifices either in-line or displaced with respect to each other. The number of the said baffle plates [70, 54] may vary from 0 - 6 each, that is, 0 to 6 of [70] and 0 to 6 of [54].

The device of the prior art has two chambers and before the fluid enters the outlet pipe [82] it experiences two right angle turns that results in pressure loss and thus loss of energy thereby adversely affecting the efficiency.

The embodiment in Fig 1 , shows the construction with two baffle plates on each side [70, 54]. The baffle plates [70, 54] have optional holes [1 14, 1 16] for the optional the rod [102]. The rod [102] when incorporated, is held at the top and bottom with an holding arrangement such as a circlip [86] with an optional filter element [104]. The spring is held in place by a spring holder [88] with a hole [1 18] and is kept in place by a circlip [84].

In another embodiment of the baffle assembly [50], the orifices [32] on the wall of the said part is enveloped by an interchangeable strip[33] that has profiled orifices as needed by different process intensification needs.

In another embodiment the filter element [104] is incorporated but not attached to the rod [102]. In another embodiment the rod [102] is not incorporated and consequently the holes [1 14, 1 12, 1 18, 1 16] through which the rod [102] passes are absent in the construction. In an embodiment, the central baffle assembly [50] is cylindrical [Fig 1 ]. However, the central baffle assembly may be of any geometric shape. The central baffle assembly [50] may be connected to external pipes [80] and [82] through which the fluid flows, through the housing [56,58]. The movable baffle [52] may be of varying geometries and optionally spring loaded as illustrated in fig 1 . The baffle plate geometry may preferably be a (disc), a cup or an inverted cup. The shape of the movable baffle [52] would take the shape of the cross section of the central baffle chamber [50]. In another embodiment the central baffle assembly [50] may have one or more orifices in the base portion of the cup or baffle [52] (not shown in the drawing).

In other embodiments the movable baffle assembly [52] may be controlled hydraulically, pneumatically, electrically, electronically or manually.

In another embodiment the movable baffle assembly [50] has a series of holes [28] on the circumference wall above of the profiled orifices [32] of the said assembly to ease movement of the fluid when the movable baffle [52] moves up and down to facilitate quick response without compromising throughput of the fluid.

The movable baffle [52] moves up and down based on the pressure exerted by the flowing fluid. It should be appreciated that the extent of movement of the said baffle varies with the pressure of the fluid flowing upwards through the central baffle assembly [50].

In other embodiments, the number of baffle plates [70, 54] can be modularly varied as per the needs of the application to get different combined flow area of the orifices [42,34].

The orifices [42, 34] in the baffle plates [70,54] may be rectangular, circular, triangular or of any other shape. Fig.3 (A) shows the typical drawing of the India Mark 2 handpump which is a popular model in worldwide use. Fig. 3(B) illustrates the water tank [90] where the device of the present invention is fitted Fig. 3(C). In this illustration the orifices [32] is in the closed position as it is covered by the movable baffle [52]. In an embodiment the invented device as shown in FIG 1 may be fitted in between the bottom cylinder containing the check valve and plunger assembly and the inlet pipe [98] to the water tank [90] of the handpump.

In another embodiment, the device may be integrated with the top of the bottom cylinder containing the check valve and plunger assembly of the handpump itself. In such a case, instead of rod [102], the central rod [94] of the handpump would pass through the holes [1 14, 1 12, 1 18, 1 16]. This configuration is shown in FIG 3(D). The device fitted with India Mark2 Handpump (FIG 2), (FIG 3C), the central baffle assembly [50] with the plurality of baffle plates [70], four such shown in FIG 2, is coaxially mounted on the water inlet [98] of the water tank [90]. The housing [56] is held in position at the top by the top cover [100], positioned by dowel pin [108] and at the bottom by enveloping the water tank inlet [98], [Fig 2(c), (d)]. The housing [56] could also be pushed or screwed into the water tank inlet [98], Before the water enters the inlet of the movable baffle assembly [50] it passes through baffle plates [70] with profiled orifices [42]. The baffle plates [70] has number of profiled orifices [42] and hole [1 14] through which the central rod [94] of the handpump passes through as shown in Fig 3(A) & FIG 3(C). The up and down motion of the central rod[94] raises the fluid and allows it to pass through the baffle plates [70], central baffle assembly [50], profiled orifices [32] against the pressure exerted by the weight and or spring on the movable baffle [52] which changes as per the pressure of fluid which is dependent on the pumping action of the handpump.

The process of substantially killing the microbes in an INDIA Mark 2 handpump comprises drawing the fluid from its source and after passing through the orifices [42] of the baffle plates [70], gets into the inlet side of the central baffle assembly [50] pushing the movable baffle [52] upwards, thereby variably opening the orifices [32] to force the fluid to flow through the said orifice at a velocity into the water tank [90] to flow out through the sprout [92] . Killing of microbes takes place as the fluid flows through the partly to fully open orifices [32] formed by movable baffle [52] and on the side of the central baffle assembly [50] as well as while passing through the profiled orifices [42] of the baffle plates [70]. After this the fluid flows into the water tank [90] and flows out through the sprout [92].

The baffle(s) plates [70] with multiple orifices [42] in the inlet portion of the housing [56] causes additional process intensification events, to enhance the microbe killing efficiency.

In another embodiment of the invention, the said device which has two or more baffle plates of appropriate thickness placed next to each other [200,201 ], FIG 4, each with profiled orifices or venturies, and can be moved relative to each other by the arrangement of bevel gears [202, 203] as shown or by other means. This movement changes the area of the vena contracta of the orifices [204] thus changing the characteristics of the process intensification.

In another embodiment, the distance between this combined baffles plates [200,201 ] or individual baffle plates [70,54] can be changed either manually or automatically with fluid pressure/ electrically / pneumatically/ electronically or combination of one or more of these, along the direction of the fluid flow.

In an embodiment of the invention, sensors to detect velocity/pressure/flow/temperature/viscosity and other physical attributes of the fluid can be placed at various places to provide signal to the actuators which then controls the movement with predefined logic to get the appropriate process intensification. The relative movement of the combined baffle plates [200,201 ] can be done manually or automatically with fluid pressure/ electrically / pneumatically/ electronically or combination of one or more of these. There is a provision of a dosing hole for fluids/ gases [205] which can be controlled by the valve [206].

The fluid enters the device from [12] and passes through the combined baffle plates [200,201 ] the shape of orifice [204] which can be adjusted by the handle [202] and then through the movable baffle assembly [50] where again depending on the pressure exerted by the fluid the profiled orifices [32] is covered or uncovered by the movable baffle [52] against the spring [66] or its own weight.

FIG 4[A] shows the combined baffle plates [200,201] side by side the relative movement of which changes the orifice profile through which the fluid passes. It has a dosing hole [205] which delivers another fluid to the orifice and is controlled by valve [206]. FIG 4[B] shows one of the combined baffle plates [201 ] which has gear [203], dosing hole[205] and profiled orifices[204], through which the fluid passes.

In another embodiment of the invention as shown in FIG5[A], the movable baffle assembly [50] is absent and fluid passes through the inlet space [1 2] to the outlet space [22] through combined baffle plates [200,201 ] with orifices [204] through the housing [56]. Since this a straight flow through without any turns for the fluid, the pressure drop between the inlet and outlet of the device is the minimum. In another embodiment of the invention as shown in FIG5[B] the distance between the combined baffle plates [200,201 ] or even single baffle plate [70 or 54] is made adjustable by having the baffle plates mounted on housing [56,58] or by other means, which can be moved relative to each other]. Though in this drawing the movable baffle assembly is not shown it may be there in other embodiments included with the baffle plate distance changing arrangement along the direction of fluid flow.

In another embodiment the number of combined baffle plates [200,201 ] which can be moved relative to each other can be more than two to get complex profiles of the orifice [204] as per the needs of the application.

The application of device is illustrated with a few non-limiting examples with examples illustrating the device performance. The invented device was fitted inside the water tank [90] as shown in Fig 3(C).

As per the protocol given below, a water sample was spiked with fresh culture of E.coli. The spiked water sample was filled in a drum which submerged the check valve of the handpump. Then by the pumping action of the handpump, this spiked water was then passed through the device of the present invention and treated sample collected from the sprout [92] of the handpump water tank [90]. The microbiological content of the samples before and after the treatment measured to check the efficacy of the treatment using the device of the present invention.

Test Protocol: a) 24 hr old culture of E.coli (ATCC 2346) with culture density 10 ⁶ cfu /ml was prepared.

b) 100 ml of above culture was inoculated into 100 liters of raw water and uniformly mixed in a ground floor tank to get final concentration of approximate 10 ³ cfu/ml.

c) The spiked raw water (before treatment) sample was collected in a 200 ml sterile sample bottle.

d) After the treatment, 200 ml of the treated sample was collected in a sterile bottle.

e) Water samples collected were transported to the laboratory in ice box at 0 to 4°C.

f) Samples were immediately subjected to microbiological analysis.

Serial dilutions were carried out, 1 ml from each dilution was inoculated in the sterile petri plates. Plates poured with sterile Plate count Agar and after solidification incubated at 37°C for 24 to 48 hr.

g) After completion of incubation the colonies were counted in the raw and treated water samples.

The following formula was used to calculate the % reduction:

Reduction (Efficacy) = Count in Raw water sample - Count in treated water sample X100

Count in Raw water sample

Results

Sample 1.

Test Method: IS 1622: 1981 (R-2009)

Sample 2 (TNTC: Too Numerous to be counted)

Table 3

Combined results

For optimum results the entry velocity to the device for water/sewage water and other water like liquids should be between 0 to 18 m/s.

The key constructional and functional improvements of this invention over the device of the prior art are as follows:

❖ Decreased pressure drop across the device lowers the energy consumption

❖ This device is capable of being modularly retrofitted or built into online variable fluid flows for enhanced process intensification including cavitation

❖ The construction achieves

• faster equalization of pressure and increases real time throughput

• substantial reduction in the number of parts

• simple and cost effective manufacture

• interchangeability of parts leading to decreased inventory for usage with a variety of pumps including centrifugal and positive displacement types by modularly replacing and/or rearranging selected components in the device

• Option to change the vena contracta of the orifices either automatically or manually

• Option to change the distance between baffle plates along the direction of fluid flow either automatically or manually

Treatment of water from diverse sources including ground water/industrial water/sewage plants in batch and continuous online flow systems using the device of the present invention produces substantially microbe free water.