RU82706U1 - COMPLETE ELECTROLYSIS PLANT FOR THE PRODUCTION OF SODIUM HYPOCHLORITE - Google Patents

Abstract

1. A complete electrolysis plant for the production of sodium hypochlorite, including at least one flow electrolyzer, in the body of which electrode modules are placed, consisting of monopolar, connected to a power source and bipolar plate electrodes, installed in parallel at a certain distance from each other, capacity for the preparation of the initial salt solution, the inlet pipe of which is connected to the dilution water supply unit, and the outlet pipe through the filter and dosing pump with the inlet of the first flow electrolyzer, and the outlet of the last electrolyzer is connected to a buffer tank for storing the resulting sodium hypochlorite, which is equipped with an ejection pipe hydrogen into the atmosphere and a branch pipe connected to a dosing pump for supplying sodium hypochlorite for water disinfection, a control panel with control and start-up equipment, pipelines with shut-off valves, characterized in that it additionally includes a solenoid valve for cutting off the water supply for diluting the initial brine into an electrolyzer, a compensator for the removal of potential from the electrolyzer and a fan mounted on a buffer tank, and all the equipment of the installation is mounted on a frame base, with a fence installed around its perimeter and equipped with means for transferring the installation. ! 2. A complete electrolysis plant according to claim 1, characterized in that the flow electrolyzer is placed between the tank for preparing the salt solution and the buffer tank, the control panel, with dosing pumps located on it, a shut-off solenoid valve and control equipment and

Description

The utility model relates to the construction of electrochemical devices, namely, to installations for the production of sodium hypochlorite by electrolysis of an aqueous solution of sodium chloride, which are used to disinfect water in public water supply systems, small water intakes, swimming pools and other objects, including disinfection of equipment and premises.

Among the known oxidative methods of water treatment, the leading place belonged to chlorination. The relative availability and low cost of liquid chlorine led to its widespread use in water treatment practice.

However, technological (rather sophisticated technology, special safety measures during transportation, storage and use, etc.), economic (maintenance of the reagent farm and additional staff of maintenance personnel), environmental (chlorine toxicity and the high probability of the formation of toxic mutagenic and carcinogenic halogen-containing organic compounds) deficiencies stimulated the search for more economical technical solutions.

In recent decades, a solution of sodium hypochlorite NaClO containing active chlorine, which is equivalent to pure chlorine in its disinfecting and sterilizing qualities, has been increasingly used all over the world. Its use practically removes all dangerous and harmful production factors inherent in the use of liquid and gaseous chlorine - a potent toxic substance.

Moreover, the sodium hypochlorite solution obtained by the electrochemical method (grade E according to TU 6-01-29-93) is the purest and least toxic product (hazard class 4 according to GOST 12.1.007-76) and has the highest efficiency.

Advantages of electrolytic sodium hypochlorite as an effective bactericidal agent, simplicity and reliability of electrolysis plants, as well as consumer interest in using a safe electrochemical disinfection method

water led to the creation of a huge number of the most diverse in their design electrolyzers, both flowing and non-flowing type.

The main difference between the operational parameters of flow electrolysers and the parameters of periodic electrolyzers is that in the first case, the electrolysis process can be considered stationary, time-independent. Moreover, if the flow rate of the brine supplied to the electrolysis, and the current load on the electrolyzer remain constant, then the concentration of the sodium hypochlorite solution withdrawn from the electrolyzer remains unchanged.

In batch electrolyzers, the concentration of sodium hypochlorite depends on the time elapsed since the start of electrolysis and, in addition, they are more complex in design and operation.

Known electrolysis installation for the production of sodium hypochlorite, protected by RF patent No. 53673 for utility model.

The essence of the utility model lies in the fact that the installation for the production of sodium hypochlorite by electrolysis of an aqueous solution of sodium chloride, including a container with an initial solution of sodium chloride, connected to two electrolysis cells, each of the electrolytic cells is connected to a collector of sodium hypochlorite solution and to the upper part of each of the electrolysis , a common line for collecting hydrogen-containing gas, connected through a separator to a collector of hydrogen-containing gas.

The presence in the inventive installation of a collector associated with electrolyzers ensures the collection of hydrogen-containing gas discharged from their upper parts, which is formed along with sodium hypochlorite during electrolysis of an aqueous solution of sodium chloride and allows it to be used as an environmentally friendly energy carrier, and not to be emitted into the atmosphere.

However, this solution requires additional safety measures, additional equipment and can only be used on large water treatment systems.

Its use on small-sized portable installations in which hypochlorite is produced in small quantities directly at the place of its consumption is inappropriate.

The disadvantages of this utility model include the use of the traditional electrolysis process, regardless of the number of flow-through electrolyzers, which requires an increase in capacity for the preparation of the initial solution of sodium chloride.

Known OSEC electrolysis unit for the production of sodium hypochlorite company "WALLACE & TIERNAN".

The electrolysis plant is protected by UK patent No. 2068016A with a priority of July 1, 1980 (according to the date of receipt of the convention application in the patent office of England), but the invention itself was created in the USA, protected by US patent No. 4248690 with priority June 28, 1980, published February 03 1981

The electrolysis installation includes four series-connected electrolysers, consisting of several electrode cells (presumably three).

An initial salt solution is introduced into the first cell, and water in equal volumes is introduced into the second and third chambers through the nozzles, and the electrolysis process in the last cell is completed by ten-fold dilution of the initial salt solution, which contains 26.4 wt.% Sodium chloride (approximately 300 g / l), i.e. dilution with water in the last electrolyzer is 1:10 (30 g / l sodium chloride). Water is supplied to dilute the concentrated brine of sodium chloride and electrolysis products through a water softener. After the concentrated brine is dissolved to the initial concentration in the saturator, the solution is fed through the brine metering pump to the first electrolytic cell of the first electrolyzer. The resulting sodium hypochlorite from the outlet of the last (fourth) electrolysis cell enters the storage tank, which is equipped with a pipe for the release of hydrogen into the atmosphere and a pipe for supplying sodium hypochlorite through a metering pump for disinfection of water.

The hydrogen is removed from each electrolyzer separately and through the hydrogen collector it is introduced into the finished sodium hypochlorite line.

The power supply of each cell is carried out from the rectifier. The installation is controlled by an automation system.

The disadvantages of the known technical solutions include:

- the difficulty of ensuring the tightness of electrolyzers due to the presence in the body of fittings for supplying water for dilution and removal of gaseous products of electrolysis;

- increased energy consumption, because as the electrolyte concentration decreases, it is necessary to change the electric mode or the design of the electrode assembly of the electrolytic cells, and this is not carried out in this invention.

The closest technical solution to the claimed utility model is an electrolysis plant for the production of sodium hypochlorite, protected by patent application No. 2006140551/15 with priority dated November 16, 2006, for which a decision was issued to grant a patent of the Russian Federation (decision dated April 24, 2008).

An electrolysis installation for the production of sodium hypochlorite includes several, at least two, flow-through electrolyzers, in the housing of which several

electrolytic cells with an electrode module consisting of monopolar, connected to a power source and bipolar plate electrodes mounted in parallel at a certain distance from each other, a water supply unit for diluting sodium chloride and a container for preparing sodium chloride solution, which is connected to a solution metering pump salt in the first cell, the output of which is connected to the input of the second cell. The output of the second cell is connected to the input of the subsequent cell, and the output of the last cell with a buffer tank for storing the obtained sodium hypochlorite, which is equipped with a pipe for the release of hydrogen into the atmosphere and a pipe connected to the second metering pump for the supply of sodium hypochlorite for disinfection of water. The dilution water supply unit is additionally connected to a pipeline for supplying an initial solution of sodium chloride to the first electrolysis cell and to a pipe installed between the outlet of the electrolysis products from the first electrolysis cell and their entry into the second electrolysis cell.

The invention improves the reliability of the electrolytic cells, provides optimization of the electrical regime of each electrolytic cell, but the installation is stationary, therefore, it does not take into account some features of portable plants designed for the production of sodium hypochlorite directly in places of water disinfection, for example, in cottages, swimming pools and ponds, etc. .P.

Such installations should be more secure in order to prevent emergencies, structurally compact and convenient for transportation.

The technical problem solved by the proposed utility model is the creation of a universal small-sized electrolysis unit having a set of equipment for producing low-concentrated sodium hypochlorite in places of its consumption, with greater safety and the ability to quickly move to another consumption object while maintaining the potential value of electrolytic cells constant throughout all stages electrolysis.

The technical result is achieved due to the fact that in the known electrolysis installation for the production of sodium hypochlorite, comprising at least one flowing electrolyzer, in the housing of which are electrode modules consisting of monopolar connected to a power source and bipolar plate electrodes mounted in parallel on a certain distance from each other, a container for preparing the initial saline solution, the inlet of which is connected to the water supply for dilution, and the output second conduit through a filter and a metering pump to an input of the first flow cell and the cell is connected to the output of the last

with a buffer tank for storing the obtained sodium hypochlorite, which is equipped with a pipe for the release of hydrogen into the atmosphere and a pipe connected to a metering pump for supplying sodium hypochlorite for water disinfection, a control panel with control and start-up equipment, pipelines with shut-off valves, changes were made, namely:

- a solenoid valve has been introduced to cut off the water supply to dilute the initial saline solution supplied to the pipeline connected to the electrolyzer;

- the body of the cell is equipped with a compensator for the removal of potential from the cell;

- a fan is installed on the buffer tank to force the removal of hydrogen;

- all equipment of the installation is mounted on a frame base with a guard installed on it;

- the base is equipped with means for transferring the installation, the ends of which are made in the form of ski ends.

In addition, to facilitate installation, capacity, housing, electrolyzers and valves are made of polyethylene.

The introduction of the electromagnetic valve, at the signal of the level sensor of the buffer capacity for storing sodium hypochlorite, allows you to cut off the water supply to the pipelines connected to the inlets of the electrolysis cells and to avoid unauthorized dilution of the initial salt solution and products of the previous electrolysis.

Considering that the casing of the electrolyzer (s) is made of polyvinyl chloride, it is possible to carry out the potential through pipelines with a conductive liquid, so the casing of the cell is equipped with a special compensator. The compensator is a hollow titanium tube connected to the ground electrode.

In order to increase the safety of people in places of water disinfection, for example, cottages, dachas, pools to accelerate the extraction of hydrogen from the buffer tank, a fan is installed on it.

The installation is a set of equipment mounted on a frame base with the ability to move it without disassembly. The arrangement of the equipment on the base is made in such a way that it is easy to provide access to the control and start-up panel, but at the same time make contact with electrolyzers difficult, as electrolysis is carried out at high currents (20-80 A).

The location of the control panel on the front side of the base makes it easier to install the fence made of corners.

For ease of transfer of the installation, the base is equipped with hollow pipes, made in such a way that allows you to transfer it manually with emphasis on the shoulders.

Below is one of the possible options for implementing the utility model.

Figure 1 shows the technological scheme for the production of sodium hypochlorite; figure 2 - design of the electrolysis installation (front view and left).

Figure 1 shows two flowing electrolysers 1, but there can be from one to four, depending on the required active chlorine productivity (kg / day), capacity 2 (PPC) for preparing the initial solution of sodium chloride, metering pump 3, a mesh filter 4, a solenoid valve 5, a rectifier 6, a buffer tank 7 for storing the obtained sodium hypochlorite, a metering pump 8 for feeding sodium hypochlorite for disinfection of water, a fan 9 mounted on a buffer tank 7, a flow meter 10 controlling the flow of water to dilute the initial p alignment of salt. The water supply unit for diluting concentrated brine of sodium chloride includes a valve (BB) (tap water) and a pipeline (BO5).

Figure 1 also shows pipelines (BO), valves, mixer (SM), level indicator (ДУ) of sodium hypochlorite installed in buffer tank 7 and other shutoff valves.

The figure 2 shows the placement of the equipment of the electrolysis plant on the base 13. It also shows a control and start-up shield 11, on which metering pumps 3 and 8, a solenoid valve 5, a rotameter 10, and other control and start-up equipment, a barrier 12 installed along to the base perimeter 13 and fastened with a control panel, a compensator 14 connected to the electrolyzer body 1 and to the pipe 15 of the buffer tank 7 through a loop 16. A hose 18 connected to a fan 9 is connected to one of the pipes 17 of the buffer tank 7 to force proper suction of hydrogen.

In addition, figure 2 shows the design of one of the ball valves 19 (in particular, connected to a metering pump 8 of sodium hypochlorite, which through a pipe or hose enters the disinfection of water).

Let us consider the operation of a utility model using the example of the operation of a complete electrolysis plant of the ELPK-4.0 type (productivity 4 kg / day for active chlorine).

A saturated solution of sodium chloride (concentration of NaCl - 280-300 g / l is prepared and stored in a container 2, into which tap water is supplied to dilute the initial saline solution to a predetermined concentration, through a valve through the ВO4 pipeline. Previously, the water passes through a softened water installation based on ion exchange resin (not shown in FIG. 1).

The intake of saline is carried out by a metering pump ND2, which controls the flow rate of the initial saline.

A working solution of sodium chloride is prepared in the BO3 pipeline, by mixing in a mixer (SM), into which the initial solution of sodium chloride is fed and through a strainer 4, an electromagnetic valve 5, tap water, the flow rate of which is controlled by a rotameter 10. Flowing through electrolyzer 1 (ELPK-4 , 0 or ELPK-6.0) the working solution is subjected to electrolysis.

The design of the cells is similar to that described in the prototype.

As a result of electrolysis, sodium hypochlorite is formed at a given concentration of active chlorine and hydrogen gas. The electrolysis products enter the electrolyzer "1A" and then through the pipeline BO1 to the buffer tank 7 through the compensator 14, loop 16 and the pipe 15. The compensator 15 is connected to the ground electrode, which prevents potential leakage on the electrodes of the electrolyzer. From the buffer tank 7, sodium hypochlorite is pumped by a metering pump 8 (LP) through a ball valve 19 for chlorination.

Dosing of active chlorine is carried out by changing the flow of the metering pump 8. The level of sodium hypochlorite in the buffer tank is monitored by sensors for the level of remote control. When the sodium hypochlorite solution reaches the upper level, the unit goes into standby mode with the electromagnetic valve 5 for supplying tap water turned off to prepare the working solution, and the rectifiers and metering pumps 3 and 8 are turned off until the sodium hypochlorite level in the buffer tank reaches the lower level. Then the cycle repeats.

Hydrogen released during the electrolysis is separated in the buffer tank 7 from the sodium hypochlorite solution and is forcedly released into the atmosphere through the pipe 17 and the hose 18 through the fan 9.

All equipment of the electrolysis unit is mounted on a frame base 13 in the following sequence: capacity 2 for preparing the initial saline solution, electrolyzers and buffer capacity 7. This arrangement makes it possible to more rationally equip the equipment with pipeline equipment. In addition, the control and start-up panel is installed at the end of the base, so that a fence is mounted on it that is mounted around the perimeter of the base.

For ease of movement, the base is equipped with means for transferring the installation made of hollow pipes, which makes it easy to carry the installation to the place of consumption.

In addition, to facilitate installation, all basic equipment is made of polyethylene, and barriers from the corners.

The proposed utility model can be implemented not only in accordance with the considered implementation example 1, but in any case it has increased safety due to the use of forced hydrogen ventilation, the use of a compensator, etc.

Installation is simple in design and easy to operate.

At present, various standard sizes of complete electrolysis plants have been developed, which will be implemented, by customer orders, starting in December 2008.

Claims (3)

1. Complete electrolysis installation for the production of sodium hypochlorite, including at least one flow-through electrolyzer, in the housing of which electrode modules are located, consisting of monopolar connected to a power source and bipolar plate electrodes mounted in parallel at a certain distance from each other, capacity for the preparation of the initial saline solution, the inlet pipe of which is connected to the dilution water supply unit, and the outlet pipe through a filter and a metering pump with an inlet the first flow-through electrolyzer, and the output of the last electrolyzer is connected to a buffer tank for storing the obtained sodium hypochlorite, which is equipped with a pipe for the release of hydrogen into the atmosphere and a pipe connected to a metering pump for supplying sodium hypochlorite for water disinfection, a control panel with monitoring and starting equipment, pipelines with shutoff valves, characterized in that it is additionally introduced an electromagnetic valve to cut off the water supply to dilute the initial saline solution into the electrolyzer, compensation Op removal capacity of the cell and a fan mounted on the buffer vessel, all installation equipment is mounted on a frame basis with the established perimeter fencing and it is provided with means for transferring the installation. 2. The complete electrolysis installation according to claim 1, characterized in that the flow-through electrolyzer is located between the tank for preparing saline solution and the buffer tank, a control panel, with metering pumps located thereon, an electromagnetic shut-off valve, and control and start-up equipment, is mounted at the end base and a fence is attached to it. 3. The complete electrolysis installation according to claim 1, characterized in that the potential removal compensator from the electrolyzer is made of a titanium tube connected to the electrolyzer body and the buffer tank nozzle, as well as to the ground electrode.