JPH02102431A - Automatic preparation of solution concentration - Google Patents

Abstract

PURPOSE:To accurately and rapidly prepare a soln. to a desired concn. by providing a system combined with an automatic density hydrometer, small-sized automatic balance and personal computer for arithmetic control, adding a diluent of a known amt. of 0.1 to 10% of the soln. to be prepd. and determining the soln. weight by the change in the concn. thereof. CONSTITUTION:The system combined with the automatic density hydrometer 2, the small-sized automatic balance 4 and the personal computer 3 for arithmetic control is provided. The diluent of 0.1 to 10% of the soln. to be prepd. is first weighed by using the small-sized automatic balance 4 and is added to the soln. to be prepd., then the soln. weight is estimated by a computer 3 from the generated change in the concn. of the soln. in place of directly weighing and determining the soln. weight. The density or sp. gr. of the soln. is then exactly detected by using the automatic density hydrometer 2 and is inputted to the computer 3, by which the density or the sp. gr. is converted to the soln. concn. The weight of the diluent to be added to the soln. in order to obtain the desired concn. of the soln. is easily calculated by the computer 3 if the soln. weight and the soln. concn. are determined in such a manner.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for preparing a solution to any desired concentration.

(Prior Art) Generally, in order to prepare a solution from a certain concentration to a target concentration, it is possible to obtain the current solution weight and solution concentration, and calculate the amount of diluent to be added to bring the solution to the target concentration.

However, in reality, the measurement of solution weight in the industrial field is based on the solution m
When the weight is large, it is often necessary to install a large-scale weighing device, such as installing a platform scale that requires foundation work. Further, in the case of a solution that generates a corrosive gas or a corrosive solution itself, maintenance of the weighing device is difficult, the life of the weighing device is short, and a large amount of expense is required.

Therefore, in general, a method is often used in which the weight of the solution is estimated from the volume of the solution, without measuring the weight of the solution. To estimate the weight of a solution from the volume of the solution, measure the volume of the solution, measure the specific gravity of the solution, and convert it to the weight of the solution.However, measurement of the solution volume often lacks accuracy due to the shape of the solution container, etc. many.

Next, to determine the solution concentration, there are analysis methods specific to each substance, but for universal acids, alkalis, salts, etc., the method of converting the solution concentration from the solution specific gravity is simple and often used.

This is a method of measuring the specific gravity of a solution using a float type hydrometer, measuring the temperature of the solution at that time, and converting it from a temperature-specific gravity-concentration conversion table.

However, when measuring the specific gravity of a solution, the float type hydrometer is prone to reading errors and has low accuracy.

In addition, when the concentration range of the solution is wide, it is cumbersome as it requires several float-type hydrometers.

Now, when determining the concentration of a solution using a float type hydrometer and preparing the solution to the desired concentration, the solution often deviates from the desired concentration. Therefore, the concentration of the solution is diluted at once to near the target concentration according to the operator's intuition, and from there, it is poured little by little, and each time, the specific gravity is measured with a float type hydrometer, and the concentration is adjusted to the target concentration using the temperature-specific gravity-concentration conversion table. are doing.

Therefore, this is a matter of bench intuition and R? J match takes time.

(Problems to be Solved by the Invention) - [The present invention requires a large amount of equipment, labor, and time to prepare rP-pure solution at a concentration in the industry. The purpose is to provide a method that can automatically mix concentrations.

(Means for Solving the Problems) In order to solve the above-mentioned difficulties, the present invention provides a system that combines a commercially available automatic density and hydrometer, a small automatic scale, and a personal computer for arithmetic control.

4′″, instead of determining the weight of the solution by directly weighing it,
A diluent of 0.1 to 10% of the solution to be prepared is weighed using a small automatic balance, added to the solution to be prepared, and the weight of the solution is estimated by a personal computer for arithmetic control from the change in concentration of the solution.

Next, instead of measuring the specific gravity of the solution using a float type hydrometer, measuring the temperature of the solution at that time, and converting it to the solution concentration using a temperature-specific gravity concentration conversion table, an automatic density hydrometer is used to measure the specific gravity of the solution. The method was to accurately detect the density or specific gravity of the solution, input it into a personal computer for arithmetic control, and convert it into a solution concentration.

Once the solution weight/solution concentration is determined as described above, the amount of diluent to be added to bring the solution to the desired concentration can be easily calculated using a personal computer for autonomous control.

(Function) In this method, first, the density or specific gravity of the solution is determined using an automatic density and hydrometer, and this value is converted into the solution concentration using a personal computer for arithmetic control.

Next, weigh o, t-to % of the solution of diluent and add to the solution to be formulated. Here, the density or specific gravity of the solution after addition of the diluent is again converted into a solution concentration using a personal computer for calculation and control.

Then, the weight of the solution is calculated from the initial concentration of the solution obtained, the amount of diluent added, and the changed concentration of the solution after the addition of the diluent using a personal computer for arithmetic control. Next, by calculating the amount of diluent to be added from the target solution concentration and adding it to the solution, automatic preparation of the solution concentration will be achieved.

Here, a calculation formula for the automatic preparation method of solution concentration of the present invention is shown.

Initial Ω of solution (%): Amount of diluent for estimating the weight of solution A (kg): Solution concentration after B concentration change (%): Weight of solution C
(kg) + Solution type ffl after addition of D diluent (kg)
:E Target solution concentration (%) = Diluent to be added to make Fl concentration fft (kg):G, then D = (CX B)/(A - C)E =
D+1 G -((Ex c)/F)-E (Example) An example of the method of the present invention will be described with reference to the attached drawings. This is carried out using a system comprising a personal computer 3 for arithmetic control, a small automatic scale 4, a diluent container 5 for estimating the weight of the solution, a solution mixing and inspection machine 6, and a diluent diversion totalizer 7.

Lead the solution sample from the solution preparation tank l to the automatic density and hydrometer 2,
The density or specific gravity of the solution was determined. The density or specific gravity of this solution was converted into a solution concentration using a personal computer 3 for arithmetic control.

Next, from the diluent amount D5, the diluent weighed using the small automatic balance 4 was added to the solution preparation tank 1, and the solution was stirred using the stirrer 6.

Again, the solution sample was introduced into the automatic density and hydrometer 2 to determine the density or specific gravity of the solution. The density or specific gravity of this solution was converted into a solution concentration using a personal computer 3 for arithmetic control.

Here, from the initial concentration of the solution, the added diluent m1, and the solution concentration after addition of the diluent, the calculation control personal computer 3 calculated the solution weight, 1 solution weight after addition of diluent, 1 solution purity. Next, enter the desired solution concentration from the keyboard into the arithmetic control personal computer, calculate the amount of diluent to be added to achieve the desired concentration, correct the temperature, and then start diluent flow! A diluent was added to the solution mixing tank (2) using a 1N totalizer (7).

Furthermore, after stirring the solution with a stirrer 6, the sample is introduced into an automatic density/density meter 2 to determine the density or specific gravity of the solution, which is converted to a solution concentration by a personal computer 3 for calculation and control, and the target concentration is It was confirmed that it was mixed.

Specifically, an example of m1 using mineral acid water is shown.

Example 1 Example 2 Initial concentration of mineral acid <3) ? 2.00 4
5.35 Estimated weight of mineral acid Tsutametsui m (kg) 10.0
20 10.010 Mineral acid concentration after concentration change (X)
? 1,45 44.98 Mineral acid weight
(kg) 1301.69 1216.89 Mineral acid type fil after water addition (kg) 1311.71 122
6.90 Mineral acid purity (kg) 937.
22 551.86 Target mineral acid concentration ($)
60.00 40.00 Added water ffi to achieve target concentration (kg) 250.32 152
．． 75 temperature 1f supplementary iEL tea addition, t water ff1 (1) 2
50.8 153.4 Obtained mineral acid concentration (%)
60.02 40.01 Difference from the target mineral acid concentration (%) + 0.02, ) 0.01 (Effect of the invention) According to this method, when a solution is prepared to a desired consistency for any purpose. , it is possible to accurately formulate the target concentration with an accuracy of 01% or less.

Preparation of the solution to the desired concentration can then be carried out automatically and quickly and without any effort.

In other words, it is sufficient to simply input the desired solution concentration into the arithmetic control personal computer using a keyboard, and no expert in compounding work is required. Moreover, the time required to prepare the solution is approximately 10 minutes or less, excluding the time for stirring the solution.
You can reach your goals quickly and reliably.

Furthermore, even if there are many solution mixing tanks, one small automatic scale that can measure 0.1 to 10% diluent of the solution to be mixed can serve as the mixing tool for many solution tanks. . There is a great economic advantage that only one small scale scale M device is required.

In addition, even in adverse working environments such as when handling corrosive solutions, precision equipment such as personal computers for calculation control can be isolated from the solution mixing tank and operated in a stable manner with ease. Can be done.

[Brief explanation of the drawing]

The figure is the same overall view according to the present invention. I: Solution mixing tank 2: Automatic density/density meter 3 = Personal computer for calculation control 4: Small automatic scale
5: Diluent container 6: Solution preparation inspection machine 7: Diluent flow rate meter

Claims (1)

[Claims] In a method for preparing a solution to a desired concentration, a system combining an automatic density/density meter, a small automatic scale, and a personal computer for arithmetic control is provided, and the concentration of the solution to be prepared is 0.1 to 0.1.
A method for automatically preparing a solution concentration, characterized by adding a known amount of 10% diluent, determining the weight of the solution from the change in concentration, and quickly and accurately preparing the solution to the desired concentration.