CN202754804U - Loop reaction device for producing phosphorus oxychloride in oxidation style with oxygen - Google Patents

Abstract

Disclosed is a loop reaction device for producing phosphorus oxychloride in an oxidation style with oxygen. The loop reaction device for producing the phosphorus oxychloride in the oxidation style with the oxygen comprises a reaction still, a circulating pump and a heat exchanger. The left side of the upper end of the reaction still is provided with a feed inlet and the bottom of the reaction still is provided with a discharge hole. A connecting pipeline is arranged on the discharge hole and is connected with the bottom of the heat exchanger. The circulating pump is arranged on the connecting pipeline between the discharge hole of the bottom of the reaction still and the bottom of the heat exchanger. The upper portion of the heat exchanger is provided with the connecting pipeline which is stretched into a feed inlet of the right side of the upper end of the reaction still and is connected with a material spray distributor arranged in the reaction still. The center of the upper end of the reaction still is provided with a gas inlet which is provided with a vertical pipeline which is almost stretched into the bottom of the reaction still and is connected with an oxygen distributor. Because the reaction still is provided with the material spray distributor and the oxygen distributor, oxygen molecules can fully contact phosphorus trichloride molecules, ratios of reactions are improved, reaction time is shorten, yield is increased and rate of equipment utilization is increased.

Description

A loop reaction device for producing phosphorus oxychloride by oxygen oxidation method

technical field

The utility model relates to a device for producing phosphorus oxychloride, in particular to a circulation reaction device for producing phosphorus oxychloride by an oxygen oxidation method.

Background technique

Phosphorus oxychloride is widely used in the chemical industry, and is an important raw material for pesticides, flame retardants, dye intermediates, and also has many applications in the electronics industry and solar energy industry.

In China, phosphorus oxychloride was mostly produced by chlorination and hydrolysis of phosphorus trichloride in the past, and the oxygen oxidation method of phosphorus trichloride was gradually developed after the 1990s. Oxygen oxidation method to produce phosphorus oxychloride is characterized by directly feeding oxygen into phosphorus trichloride for reaction. This is an exothermic reaction. Because the reaction is simple and does not produce by-products, it is easy to control and has a high yield. The production is in the form of multiple reactors connected in series, trying to make oxygen absorbed by phosphorus trichloride to generate phosphorus oxychloride. But this reaction takes a long time (it takes 40-48 hours to complete), and part of the oxygen is dissipated, so the utilization rate is low. In order to improve these shortcomings, it is proposed to use the circulation process to improve the efficiency. The feature of the circulation process is that the material in the reactor is pumped out and input repeatedly by a circulating pump, so that the material is fully contacted with oxygen to generate a reaction, and the heat of reaction is removed through the heat exchanger outside the tank, so that the reaction is carried out at a lower temperature. next.

In the prior art circulation process, there are generally only reactors, heat exchangers, and circulating pumps, and the reactors are simply provided with feed inlets and outlets. The mixed reaction of materials and oxygen is insufficient, and the reaction probability is low. The production time is longer, and the production efficiency needs to be improved.

Contents of the invention

The utility model aims at the deficiencies of the prior art, and provides a circulation reaction device for producing phosphorus oxychloride by oxygen oxidation method which fully reacts with oxygen, has short reaction time and high production efficiency.

In order to solve the above technical problems, the utility model provides the following technical solutions: a circulation reaction device for producing phosphorus oxychloride by oxygen oxidation method, including a reaction kettle, a circulating pump, and a heat exchanger. A feed port is provided, a discharge port is provided at the bottom end, and a connecting pipeline is provided on the discharge port to connect with the bottom end of the heat exchanger. Equipped with a circulating pump, which is characterized in that there is a connection pipe on the top of the heat exchanger extending into the circulating material port on the right side of the top of the reactor, which is connected to the material spray distributor installed in the reactor, and an air inlet is provided in the center of the top of the reactor. The air inlet is provided with a vertical pipe extending into the bottom of the reactor and connected with the oxygen distributor.

The material spray distributor is composed of a vertical pipe and a ring-shaped coil, and through holes are evenly distributed on the ring-shaped coil. As a preference, a hole is opened every 2.7 degrees along the center of the circle of the ring-shaped coil. A group of through holes is opened every 2.7 degrees, and the number of a group of through holes is 3, preferably 130 groups in total, which are evenly distributed on the circular coil, and each group has 3 holes of φ5mm.

The oxygen distributor is a ring-shaped coil with through holes evenly distributed on the ring-shaped coil. As a preferred ring-shaped coil, a group of holes is provided every 9.2 degrees along the center of the circle, and a group of holes are opened every 9.2 degrees. There are 4 through holes in one group, preferably 39 groups in total, which are evenly distributed on the circular coil, and each group has 4 holes of φ4mm.

As a further improvement of the present utility model, two circulating pumps are arranged in parallel on the connecting pipeline between the discharge port at the bottom end of the reactor and the bottom end of the heat exchanger. This arrangement effectively prevents the entire device from shutting down due to the damage of any circulating pump, effectively shortens the maintenance period of the device, and improves the overall production efficiency.

As a further improvement of the utility model, the heat exchanger is a graphite heat exchanger.

As a preference of the present utility model, the materials of the material spray distributor and the oxygen distributor are titanium metal. Through this setting, the device can run stably for a long time without being corroded and prolong the service life.

Beneficial effects of the utility model: the utility model is provided with a material spray distributor and an oxygen distributor in the reactor to effectively and fully make the oxygen molecules contact with the phosphorus trichloride molecules, improve the reaction probability, shorten the reaction time, and make the original need The reaction that can be completed in 40-48 hours is shortened to 8-10 hours, which increases the output and improves the utilization rate of the equipment. Due to the accelerated reaction speed, the reaction temperature originally controlled at 80-90°C can be reduced to 70-75°C ℃, which increases the safety of the reaction. Since the cyclic reaction can make full use of oxygen, the oxygen consumption per ton of phosphorus oxychloride is reduced from 110-113 kg to 105 kg per ton, which is close to the theoretical value of 104 kg. Oxygen utilization rate is improved. Due to the use of graphite heat exchanger, the heat exchange performance is better. The thermal conductivity of graphite is much larger than that of stainless steel and carbon steel. General steel heat exchangers are often welded with many steel pipes, which will produce many welds, while phosphorus trichloride and phosphorus oxychloride are highly corrosive and not suitable for use, while graphite materials have strong chemical stability ( Inert), good machinability, very suitable for use in this project.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Figure 2 is the front view of the oxygen distributor.

FIG. 3 is a top view of FIG. 2 .

FIG. 4 is a cross-sectional view along line A-A of FIG. 3 .

Figure 5 is a front view of the material spray distributor.

FIG. 6 is a top view of FIG. 5 .

Fig. 7 is a B-B sectional view of Fig. 6 .

Detailed ways

A circulation reaction device for producing phosphorus oxychloride by an oxygen oxidation method, comprising a reactor 001, a circulation pump 002, and a heat exchanger 003. The top left side of the reactor 001 is provided with a feed inlet 011, and the bottom end is provided with a The outlet 012 is provided with a connecting pipeline 004 connected to the bottom end of the heat exchanger 003, and the connecting pipeline 004 between the outlet 012 at the bottom of the reaction kettle 001 and the bottom end of the heat exchanger 003 A circulating pump 002 is provided, and a connecting pipeline 004 is provided on the top of the heat exchanger 003, which extends into the circulating material port 013 on the right side of the top of the reactor 001, and is connected with the material spray distributor 005 arranged in the reactor 001, and the top of the reactor 001 There is an air inlet 014 in the center, and a vertical pipe 015 is arranged in the air inlet 014 to extend into the bottom of the reactor 001 and connect with the oxygen distributor 006. The outlet 012 at the bottom of the reactor 001 is connected to the heat exchanger 003 Two circulating pumps 002 are arranged in parallel on the connecting pipeline 004 between the bottom ends, and the material spray distributor 005 is composed of a vertical pipe 051 and an annular coil 052. Holes 053, the annular coil 052 is provided with a group of through holes 053 every 2.7 degrees along the center of the circle, the number of a group of through holes 053 is 3, preferably 130 groups, evenly distributed on the annular coil, each Open 3 holes of φ5mm. The oxygen distributor 006 is a ring-shaped coil with through holes 061 evenly distributed on the ring-shaped coil. A group of There are 4 through holes 061 in one group, preferably 39 groups, which are evenly distributed on the ring-shaped coil, and each group has 4 holes of φ4mm.

The heat exchanger 003 is a graphite heat exchanger, and the materials of the material spray distributor 005 and the oxygen distributor 006 are titanium metal.

This embodiment is specifically realized by the following method: add metered phosphorus trichloride into the reactor, turn on the circulation pump 002, preferably two circulation pumps 002 alternately, so that the material is sprayed out from the material spray distributor 005. In addition, after the liquid oxygen is converted into gaseous oxygen by the vaporizer, it is also sprayed out from the oxygen distributor 006, and reacts with phosphorus trichloride to generate phosphorus oxychloride and release heat. Control oxygen flow rate 14-15m3/h during reaction. When the circulating material passes through the graphite heat exchanger, the heat is transferred to the coolant in the graphite heat exchanger, and the temperature in the reaction kettle 001 is controlled at 70-75°C. After 8 hours of reaction, when the temperature in the kettle starts to drop, gradually reduce the oxygen flow amount, through sampling analysis, when the analysis boiling range > 97.5%, it is determined that the reaction is over.

Claims (8)

1. A circulation reaction device for producing phosphorus oxychloride by an oxygen oxidation method, comprising a reactor, a circulating pump, a heat exchanger, the left side of the top of the reactor is provided with an inlet, and the bottom is provided with an outlet , the discharge port is provided with a connecting pipeline connected to the bottom end of the heat exchanger, and a circulating pump is provided on the connecting pipeline between the discharge port at the bottom end of the reactor and the bottom end of the heat exchanger, which is characterized in that the top of the heat exchanger is set A connecting pipeline extends into the circulation port on the right side of the top of the reactor, and connects with the material spray distributor installed in the reactor. There is an air inlet in the center of the top of the reactor, and a vertical pipe is arranged in the inlet to extend into the reactor. The kettle is near the bottom and connected to the oxygen sparger. 2. a kind of circulating reaction device that produces phosphorus oxychloride with oxygen oxidation method according to claim 1, it is characterized in that on the connection pipeline between the discharge port at the bottom of the reactor and the bottom of the heat exchanger, it is arranged in parallel There are two circulation pumps. 3. A kind of circulation reaction device producing phosphorus oxychloride by oxygen oxidation method according to claim 1, it is characterized in that material spray distributor is made up of vertical pipe and annular coil, and described annular disc Through holes are evenly distributed on the tube. 4. A kind of circulation reaction device for producing phosphorus oxychloride by oxygen oxidation method according to claim 3, it is characterized in that said ring-shaped coiled pipe is provided with a group of through holes every 2.7 degrees along the center of the circle, a group of through holes The number of holes is 3. 5. A kind of circulation reaction device producing phosphorus oxychloride with oxygen oxidation method according to claim 1, it is characterized in that the oxygen distributor is an annular coil, and the said annular coil is evenly distributed with hole. 6. A kind of circulation reaction device for producing phosphorus oxychloride by oxygen oxidation method according to claim 5, it is characterized in that said ring-shaped coiled pipe is provided with a group of through holes every 9.2 degrees along the center of the circle, a group of through holes The number of holes is 4. 7. A kind of circulating reaction device that produces phosphorus oxychloride with oxygen oxidation method according to claim 1, is characterized in that heat exchanger is graphite heat exchanger. 8. A kind of circulating reaction device that produces phosphorus oxychloride with oxygen oxidation method according to claim 1, it is characterized in that described material spray distributor, oxygen distributor material is metal titanium.

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