Process and apparatus for addition of a chemical to a process stream

Abstract

The invention relates to a process for addition of a liquid chemical to a process stream by means of a mixing apparatus (10, 200), comprising a housing, especially a mixing tube (20), at least one fluid feed orifice (30), a chemical feed orifice (14), a dilution fluid feed orifice (18) and at least one outlet orifice (60) to a process stream (70). The process according to the invention is characterized in that a chemical stream from the chemical feed orifice (14) and a dilution fluid stream from the dilution fluid feed orifice (18) are added to a fluid stream and the fluid stream, after addition of chemical stream and dilution fluid stream, is supplied, preferably sprayed, via an outlet orifice (60), into a process stream (70), especially accelerated through a nozzle.

Description

technical field [0001] The invention relates to a method of mixing liquid chemicals into a process stream by means of a mixing device, as well as to a device for mixing liquid chemicals into a process stream and a chemical supply system comprising such a device. Background technique [0002] The dosing and subsequent dosing of chemicals (for example in the paper manufacturing process) imposes special requirements, especially with regard to the efficient dosing and dosing of chemicals on demand. Dosing on demand means, for example, in the papermaking process that chemicals are added to the process flow of the paper machine according to the amount of fiber. By means of such measures, the amount of added chemicals can be significantly reduced in the papermaking process. Another reason for efficient use of chemicals is the high energy required to heat fresh water to dissolve or dilute the process chemicals. Such heating is beneficial to avoid thermal shock when mixing chemical...

AI Technical Summary

Problems solved by technology

[0006] A disadvantage of the device according to WO-A-2005 / 32704 is that on the one hand a separate mixing space in the form of a mixing chamber has to be provided, on the other hand the mixing chamber is separated from the fluid flow and therefore does not combine a completely mixed fluid flow, chemical flow and The dilution stream is injected into the process stream, but the mixing of the chemical and dilution streams is done separately from the fluid stream

This of course leads to the cross-section of the inflow line or the nozzle dimensioning of the mixing device not being dimensioned for sufficiently high flow velocities to prevent such deposits

On the other hand, if the cross section is lowered, this can lead to clogging and thus to a malfunction of the mixing device, especially the nozzle, which leads to a production stop and replacement of the entire nozzle or inflow line

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