METHOD AND APPARATUS FOR THE INTIMATE MIXING OF FLUIDS

Abstract: A method of intimately mixing fluids in a two stage process comprising the steps of subjecting a continuous flow of an aggregation of fluids to free vortex flow having axial and tangential velocity components and then substantially removing the tangential velocity component to substantially recover the tangential velocity energy to provide a discharge flow which is substantially axial.

Description: "METHOD AND APPARATUS FOR THE INTIMATE MIXING OF FLUIDS" This invention relates to the mixing of fluids and provides an improved method and apparatus for carrying out intimate mixing of fluids. In industrial chemical processes it is important that the components for a chemical reaction be intimately and thoroughly mixed in order that the chemical reaction can be completed. This invention- has- as its object the achievement of the foregoing particularly as applied to the intimate mixing of liquid droplets with a pressurised gas flow. It is a further object of the invention to carry out the mixing operation with minimum pressure loss. It is to be understood that the invention is also applicable to the mixing of gases and the mixing of liquids. The term free vortex flow, as used hereinafter, means a rotating flow in which there is present axial and tangential velocity components and wherein the tangential velocity component in greatest at the axis of the flow and decreases with radial distance from the axis. Broadly, the invention provides a method of intimately mixing fluids in a two stage process comprising the steps of subjecting a continuous flow of an aggregation of fluids to free vortex flow having axial and tangential velocity components as hereinbefore defined and then substantially removing the tangential velocity component to recover the tangential velocity energy and to provide a discharge flow which is substantially axial. The invention further comprises apparatus for carrying out the above method wherein the apparatus includes a fluid passageway with an inlet end and a discharge end and at least a vortex zone and a axial flow zone downstream from said vortex zone, vortex flow promoting guide vanes extending into said fluid passageway in said vortex zone shaped and disposed to promote free vortex flow with axial and tangential velocity components as hereinbefore defined in fluids passing through said vortex zone and axial flow promoting guide vanes extending into said fluid passageway in said axial flow zone shaped and disposed to substantially remove tangential velocity and recover the tangential velocity energy from fluid passing through said axial flow zone and thereby provide substantially rotation fee fluid discharge from said discharge end of said device. The vortex promoting guide vanes may be part of an assembly which is driven and rotates about the axis of the vortex flow to impart energy to the vortex flow. A representative example of an apparatus for carrying out the invention will now be described with reference to the accompany schematic partially sectioned elevation of a deodorising unit for sewer gas. The apparatus comprises an annular chamber 1 with a centrally mounted hub 2. The chamber has an inlet end 3 fitted with flow contol louvres 4 (these are not essential to the operation of the apparatus) and a pressurised gas flow F from a suitable source enters the chamber 1 through the end 3. Adjacent the end 3 there are a number of equally circumferentially spaced radially oriented guide vanes or blades 5 (hereinafter referred to as vanes) which are twisted in a predetermined manner along their lengths so as to impart a rotational velocity to the axially flowing gas. The shaping of the vanes 5 promotes rotational flow as a free vortex flow in a vortex zone where the tangential velocity component of flow is greatest adjacent the centre of the chamber and descreases with radial distance from the centre of the chamber. The creation of the tangential velocity in the gas flow utilises some of the energy from the gas flow and there is a corresponding pressure drop downstream from the guide vanes 5 as the tangential velocity of the gas flow increases through the vanes 5. Upstream from the vanes 5 there are misting jets 6 to introduce chlorine dioxide into the sewer gas flow. The vortex flow of gas creates an intimate mix of sewer gas and chlorine dioxide as it progresses as a swirling mass towards the exit end 7 of the chamber. The intimate mixing ensures a complete chemical reaction between the chlorine dioxide and the hydrogen sulphide in the sewer gas (the offensive smell component of the sewer gas) and the desired result is the formation of solid sulphur particles which are entrained In the gas flow. Adjacent and upstream from the exit end 7 of the chamber 1 there Is an axial flow zone provided with guide vanes 8 shaped to substantially remove the tangential velocity component of the gas flow created by the guide vanes 5 and the result is a substantially rotation fee axial gas flow from exit end 7 of the chamber I. There is an associated recovery of energy from the gas flow and a pressure increase as the gas flow passes through the vanes 8 and there is a corresponding decrease in the tangential flow velocity. Preferably the vanes 8 have a shape, orientation and spacing substantially complementing that of the vanes 5. As will be understood that vanes 5 and 3 may have any shape, orientation and spacing which will impart to and remove from the fluid flow the tangential velocity required for the intimate mixing process and the recovery of energy. To prevent the sulphur particles entrained in the gas flow from exiting to atmosphere a sulphur trap is provided in the form of water sprays 9 and a mist trap 10. The sulphur particles in water suspension is then treated in a manner not forming part of this invention. The result is a discharge from the apparatus of a substantially axial flow of clean odour free air.

Claims: CLAIMS : 1. A method of intimately mixing fluids in a two stage process comprising the steps of subjecting a continuous flow of an aggregation of fluids to free vortex flow having axial and tangential velocity components as hereinbefore defined and then substantially removing the tangential velocity component to substantially recover the tangential velocity energy to provide a discharge flow which is substantially axial. 2. Apparatus for carrying out the method of claim 1 wherein said apparatus includes a fluid passageway with an inlet end and a discharge end and at least a vortex zone and a axial flow zone downstream from said vortex zone, vortex flow promoting guide vanes extending into said fluid passageway in said vortex zone shaped and disposed to promote free vortex flow with axial and tangential velocity components as hereinbefore defined in fluids passing through said vortex zone and axial flow promoting guide vanes extending into said fluid passageway in said axial flow zone shaped and disposed to substantially remove tangential velocity and recover the tangential velocity energy from fluid passing through said axial flow zone and thereby provide substantially rotation fee fluid discharge from said discharαe end of said device. 3. Apparatus as claimed in claim 2 wherein the fluid passageway is annular and said vortex flow promoting guide vanes are equally circumferentially spaced and radially oriented around said annular passageway. 4. Apparatus as claimed in claim 3 wherein the axial flow promoting guide vanes have a shape and orientation which is complementary that of the vortex flow promoting guide vanes. 5. Apparatus as claimed in- claim 1 including means to discharge droplets of liquid into said passageway upstream from said vortex zone. 6. Apparatus as claimed in claim 1 including a cleaning means downstream from said axial flow zone to recover solids entrained in the fluids leaving the axial flow zone. 7. Apparatus as claimed in 6 wherein the cleaning means comprises water sprays upstream from a filter means extending across said passageway.

Inventors: RODGERS WILLIAM, RODGERS, WILLIAM
Applicants: RODGERS WILLIAM, RODGERS, WILLIAM
Application year: 1989
Main classification: B01F5
IPC codes: B01F5