Process control
OwnerMark U. Krumhanslinventor
Life of this patent
Estimating the term…
Abstract
A general purpose apparatus for measuring the chemical and physical state of flowing liquid materials and chemical additives and for introducing chemical materials to the stream uses a Venturi or other apparatus in which differential pressure is developed as an incident to fluid flow. It is arranged to be used both as a sample pump, a chemical additive pump, and as a differential pressure meter for use in calculating flow rates. The process method includes chemical addition at rates determined by pressure differential at the Venturi and for times which bear a selected relation to that differential pressure, temperature and the chemical state of the liquid. It also includes special temperature comparisons and flushing of chemical addition lines on an optional basis.
Claims23
For use with a system which includes a means for causing a flow of fluid material along a main flowpath, a chemical sensing and controlling unit, comprising:
- pressure differential sensing means connected in said main flowpath and having a high pressure outlet port at its input side and a lower pressure inlet port downstream from said outlet port for developing a differential pressure between said ports the magnitude of which varies with flow rate along said main flowpath:
- a sensing and chemical addition flowpath extending from said outlet port to said inlet port;
- sensing means for measuring the chemical state of the fluid flowing in said sensing and chemical addition flowpath;
- and
- chemical adding means for utilizing the flow of fluid in said sensing and chemical addition flowpath for introducing into said main flowpath quantities of a substance capable of altering said chemical state.
The method of processing fluid materials which comprises the steps of:
- forcing said fluid material to flow through a differential pressure producing device which is fitted with and outlet port and a downstream inlet port;
- interconnecting said ports through a flowpath such that a portion of said fluid material flows therethrough;
- measuring the chemical state of the fluid flowing through said flowpath;
- and
- subsequently introducing chemicals into said flowpath for a period bearing a selected relation to the measured chemical state of said fluid.
The method of calibrating a differential pressure measuring transducer which is connected across an apparatus in which a differential pressure, variable as a function of flow rate, is produced as an incident to flow and which method comprises the steps of:
- measuring pressure differential across said transducer in the absence of any significant flow in parallel with said apparatus;
- measuring pressure differential across said transducer in the presence of flow, substantially without resistance, in parallel with said apparatus;
- and
- adjusting the measurement taken in the absence of parallel flow by an amount which is a function of the measurement taken during the period of parallel flow.
Dependencies are inferred from the claim text.