SU564296A1 - Method for automatic control of ammophos production process - Google Patents

Description

(54) METHOD FOR AUTOMATIC REGULATION OF THE PROCESS OF OBTAINING AMMOPHOS

one

The invention relates to the field of automation of chemical production, and in particular to a method for controlling the quality of endogenous ammophos, and can be used in the chemical industry.

There is a known method for controlling the process of neutralizing phosphoric acid ammonia by maintaining the temperature in the reaction dawn by changing the heating rate.

steam depending on the consumption of phosphoric acid and the viscosity of the resulting product ..

However, I affect only temp. The reaction room, without regard to the ratio of incoming reagents, is insufficient for continuous control of the quality of the product.

There is also known a method for regulating the process of obtaining a translated

ammophos. by stabilizing the pressures of phosphoric acid and ammonia supplied to the reactor, and adjusting the ratio of the flow rates of ammonia and phosphoric acid with a correction for the pH of the finished pulp 2.

However, this method of regulation is not free from drawbacks, since measuring the pH of the finished pulp makes it difficult to deposit a dense layer of sediment on the surface of the electrodes and the presence of impurities of fluoride salts in the bullets, which leads to a decrease in the quality of the product.

The purpose of the invention is to improve the quality of the finished product.

To this end, the ratio of the costs of phosphoric acid and ammonia is adjusted for the temperature of the product in the reactor and the consumption of phosphoric acid.

The quality of the finished product is mainly determined by the ratio of incoming reagents, and each value of the ratio of starting materials corresponds to a strictly defined reaction temperature.

FIG. Figure 1 shows the scheme of pH dependence of the finished product on the reaction temperature at a constant flow rate of ammonia and various acid loads (respectively, directly 1, 2 and 3 at flow rates of 450, 560 and 690 l / h).

In order to maintain the quality of the avdogon ammophos at a given level, it is necessary to maintain a certain reaction temperature for each ratio of incoming reactants.

FIG. 2 is a schematic diagram of the automatic control of the quality of endogenous ammophos.

Regulators 1 and 2 with the help of actuators 3 and 4 maintains constant pressure of ammonia and phosphoric acid. The signals from sensors S and 6 of the flow meters of ammonia to phosphoric acid through measuring devices 7 and 8 are sent to the ratio controller 9, which, depending on the signal from the secondary device 10 and the thermocouple 11 located in the reactor 12, performs a pulse on the regulating organ 13 supplying ammonia to the reactor, thereby maintaining the required ratio of reactants.

The automatic control system provides an additional circuit allowing the introduction of a correction into the ratio control circuit. The signal from the measuring device 8 is a reference for the secondary device 10 with an integrated regulator. The signal, which is proportional to the current value of the temperature in the reaction zone, is fed to the secondary device 1O as a variable. The magnitude of the corrective amendment

when the consumption of phosphoric acid is changed, it acts on the regulator 9 of the ratio and changes until the temperature in the area of the flue gas reaches the value corresponding to the modified value of phosphoric acid.

Using this method allows you to more efficiently conduct the process of obtaining endogenous amfos, improve the quality of the product and reduce the loss of ammonia with exhaust gases.

Claims (2)

1. USSR author's certificate No. 471299, cl. From 01 to 25/12, 1972 2. Maisel Yu, A. and others. Automation of the production of phosphorus and phosphorus-containing products, M., Himi, 1973, p. 329. 22ff (i c) phosphorus / g ig.g. 8 atmosphere of air temperature