CN101235105B - Method for agglomerating solution-polymerized rubber - Google Patents

Abstract

The invention relates to a solution polymerization rubber aggregation method, which comprises using steam as energy and overheat water as separation medium, completely mixing rubber liquid and overheat water, increasing temperature, evaporating most solvents at the instant of ejecting rubber solution-hot water into the hot water in aggregation pot to complete the pre-aggregation of rubber solution and reduce the solvent consumption in aggregation. The invention is suitable for aggregation in polybutadiene rubber production and suitable for the aggregation in solution polymerization rubber liquid sedimentation method to complete separation of polymer and solvent synchronous via flash evaporation and sedimentation methods, thereby resolving the contradictory between aggregation energy consumption and material consumption in sedimentation method. The invention uses pre-aggregation technique in sedimentation method to reduce solvent consumption without additional energy consumption, thereby resolving the contradictory between aggregation energy consumption and material consumption in sedimentation to optimiz aggregation processing parameters and realize energy saving and discharge reduction.

Description

Solution polymerization rubber coagulation method

technical field

The invention belongs to a separation method, in particular to a coagulation method of solution-polymerized rubber.

Background technique

In addition to polybutadiene, the butadiene rubber polymer glue still contains solvent and unreacted butadiene, which must be coagulated and dried to obtain butadiene rubber products. In the process of nickel-based butadiene solution polymerization, the reaction temperature of the final reactor is generally controlled at about 95°C, and the conversion rate of butadiene can reach about 85%. Glue tanks generally adopt heat preservation measures and glue flash technology. After the glue enters the glue tank, most of the unreacted butadiene is flashed and discharged from the top of the tank and recovered. The glue in the decondensation tank can be regarded as a homogeneous solution of polybutadiene and solvent. Therefore, the coagulation process It can be regarded as a process in which the solvent is removed.

The energy consumption (steam consumption) and material consumption (solvent consumption) of butadiene rubber production mainly occur in the glue coagulation process, and most of the coagulation solvent consumption is directly discharged into the atmosphere in the post-processing system. Therefore, coagulation energy consumption and material consumption are important indicators of the technical level of coagulation production. It is not only related to the economic benefits of butadiene rubber production, but also related to environmental protection issues, making the research on coagulation energy saving and consumption reduction an important aspect of energy saving and emission reduction in butadiene rubber production. research topic.

Since the industrialization of butadiene rubber, the water analysis method has been used to separate the polymer and the solvent at home and abroad, that is, the glue is sprayed into the hot water of the coagulation kettle, and the solvent is vaporized with steam and taken out of the kettle. In the initial stage of butadiene rubber production in my country, in order to ensure a certain production capacity and complete coagulation of the glue, a higher coagulation temperature and a lower operating pressure were adopted, and the steam consumption reached more than 10t/t rubber, and high energy consumption became the main factor in the coagulation process. contradiction.

Practice and research on condensation energy saving theory have proved that, at a certain condensation temperature, the steam consumption decreases with the increase of operating pressure. In order to reduce steam consumption, during the coagulation process of double-tanks, maintaining a certain operating pressure in No. 1 and No. 2 tanks is called pressure-holding coagulation, also known as isobaric coagulation. With the use of isobaric coagulation, as the operating pressure increases, the energy consumption decreases and the material consumption increases, which highlights the contradiction between energy consumption and material consumption, resulting in the differential pressure coagulation technology.

In the double-tank condensation process, about 95% of the solvent is evaporated from the No. 1 tank, and most of the steam consumption is in the No. 1 tank, so. No. 1 kettle adopts higher operating pressure, focusing on energy saving; No. 2 kettle adopts lower operating pressure, focusing on reducing consumption, which is called differential pressure coagulation. With differential pressure condensation, the No. 2 kettle is no longer just a continuation and supplement of solvent evaporation from the No. 1 kettle, which eases the contradiction between energy saving and consumption reduction.

Theoretical research on energy-saving and consumption-reducing coagulation by water analysis proves that the sensible heat and latent heat steam consumption required by the solvent in the coagulation process is less than one ton per ton of glue, which is slightly affected by operating conditions and can be regarded as a certain value. The key to energy saving is to reduce The steam consumption of the gas phase solvent; in the condensation process of the water precipitation method, the driving force of solvent vaporization is high, the material consumption is low, and the energy consumption is high; the driving force of solvent vaporization is low, the material consumption is high, and the energy consumption is low. , which is also the link connecting energy consumption and material consumption. Condensed energy consumption and material consumption are a pair of contradictions linked by the driving force of solvent vaporization. The relationship curve between the driving force and the vapor consumption of the gas phase solvent taken out from the coagulation kettle is shown in Figure 1, X represents the solvent vaporization driving force (MPa), Y represents the steam consumption t/t glue, and the condensation temperature of the curve in the figure: 1-92 °C; 2-94 °C; 3-96 °C; 4-98 °C; 5-100 °C; 6-102 °C. It reveals the relationship between condensing temperature, operating pressure, energy consumption and material consumption, and becomes a reliable basis for selecting and optimizing condensing process conditions.

Contents of the invention

The present invention aims at overcoming the deficiencies of the prior art, and has developed a method of reducing material consumption, improving the effect of dispersant and alkali cleaning effect without increasing energy consumption; on the basis of reducing material consumption, optimizing the coagulation process conditions, Further energy-saving solution polymerization rubber coagulation method.

The coagulation method of solution-polymerized rubber of the present invention is to increase the pre-coagulation process before the coagulation of the glue, use steam as the energy source, and use superheated water as the medium to allow the glue and superheated water to fully mix and heat up. -The moment the hot water enters the hot water in the coagulation kettle, most of the solvent is flash vaporized, reducing the solvent consumption without increasing energy consumption, optimizing the coagulation process conditions and further saving energy on the basis of reducing consumption, and reducing the energy consumption of the coagulation process A method that contradicts material consumption. Concrete invention content is as follows:

a. Heat water to 115℃～130℃ to make superheated water, and add polycarboxylate sodium dispersant and sodium hydroxide lye, the amount of dispersant added is 1×10 ^-4 ～5×10 of the dry glue mass ^-4 , the amount of lye added is between 9 and 10 to control the PH value of the condensed hot water;

b. Fully mix the glue solution with the superheated aqueous solution prepared in step a to obtain a heterogeneous mixture of glue solution-hot water at 113°C to 125°C;

c. Spray the glue-hot water heterogeneous mixture into the coagulation kettle with hot water at 93°C to 100°C, and complete the pre-coagulation process of the glue;

d. The pre-coagulated glue is kept under stirring in the coagulation tank and the residence time is controlled to be 40-50 minutes, that is to say, the coagulation process of the water analysis method is completed.

As a further improvement of the present invention, in step b, the mixing volume ratio of glue solution and superheated water is 1:2-3.

As a further improvement of the present invention, the injection pressure in step c is 0.4MPa-0.8MPa.

The principle of pre-coagulation: change the way of adding steam for partial coagulation, fully mix the glue with the superheated water added with dispersant and lye, let the glue-hot water store enough solvent vaporization potential, and spray it with glue-hot water At the moment of entering the condensed hot water, most of the solvent is flashed under reduced pressure and vaporized rapidly.

The solution polymerization rubber coagulation device of the present invention is composed of a steam-water mixer, a glue mixer, a pre-condensation liquid nozzle and a coagulation kettle. The outlet pipeline of the steam-water mixer is connected to the pipeline of ^the glue mixer, and the outlet of the glue mixer is connected to the pre-condensed liquid nozzle ^. Connect with 2 ^# coagulation kettle. Among them, there are circulating water inlet a and steam inlet b on the steam-water mixer, and its outlet pipeline has dispersant inlet c, lye inlet d and glue inlet e; there are circulating water inlet f and steam inlet f on the 1 ^# coagulation kettle Inlet g; there are steam inlet i, gas phase precipitate outlet j and colloidal water outlet k on the 2 ^# condensation kettle. The soda mixer mixes steam and circulating hot water to generate superheated water; the glue mixer fully mixes the glue with superheated water to obtain a high-temperature glue-hot water heterogeneous mixture. The glue mixer is a static The mixer and the static mixer must be able to fully mix the glue and superheated water; the pre-coagulated liquid nozzle is to spray the glue-hot water into the condensed hot water, and another important function of the pre-coagulated liquid nozzle is to maintain pressure. Function to ensure that the superheated water and solvent in the pre-coagulation system do not vaporize.

Pre-condensation process design basis and process condition selection:

In the pre-coagulation process, the properties of solvent and water are very different, and they can be regarded as two systems that do not affect each other; polybutadiene and solvent are no longer polybutadiene dispersed in the solvent in a molecular state. The molecular weight of butadiene is very different from that of the solvent, and its molar fraction is small, so the flash vaporization of the solvent is negligibly affected by polybutadiene. Therefore, for the pre-coagulation process, the heat balance of the adiabatic flash evaporation of the solvent can be calculated To determine the minimum allowable temperature of superheated water and the corresponding pre-condensation temperature.

In the pre-coagulation process, the glue-hot water temperature, that is, the pre-coagulation temperature is the key to affect the pre-coagulation effect. The role of steam is realized through the full mixing of glue and superheated water. Therefore, from design to production, all The hot water temperature is used as the characterization of the pre-coagulation temperature, and the superheated water temperature becomes an important process control condition in the pre-coagulation process. Taking the pre-coagulation process of butadiene rubber as an example, the minimum allowable temperature of superheated water and the corresponding pre-coagulation temperature are calculated.

①Minimum permissible temperature of superheated water

Based on the production of one ton of glue, calculate the minimum allowable temperature of the superheated water that can meet the energy required for the pre-coagulated gel solution. The following settings are made according to the production practice.

Setting: the volume of glue solution for producing one ton of glue is about 8.5m ³ ;

The glue solution that produces one ton of glue contains 4.5 tons of solvent;

The solvent vaporization rate of 1# kettle is 95%;

The glue temperature is 85°C;

Condensation temperature is 96℃～98℃;

Pre-condensed water/glue 2~3;

Solvents are based on hexane.

Other relevant physical and chemical constants are listed in Table 1.

Table 1 The physical and chemical constants related to the condensation process

meaning unit value Hexane heat capacity kJ/(kg·℃) 2.27 Heat capacity of butadiene rubber kJ/(kg·℃) 2.09 heat capacity of water kJ/(kg·℃) 4.19 Enthalpy of vaporization of hexane kJ/kg 3.36×10²

a. Sensible heat

In the pre-coagulation process, the sensible heat _Q1 required to heat the glue to the coagulation temperature is:

Q ₁ =(C ₁ ×m ₁ +C ₂ ×m ₂ )×(t ₃ -t ₄ ) (1)

In the formula, the heat capacity of C ₁ -solvent, kJ/(kg·℃);

C ₂ - heat capacity of butadiene rubber, kJ/(kg·℃);

m ₁ - the mass of solvent in the glue solution for producing 1 ton of glue, kg;

m ₂ - production of butadiene rubber, 1000kg;

t ₃ - condensation temperature, °C;

t ₄ - glue temperature, °C.

b. Latent heat

In the pre-coagulation process, _the latent heat Q required for the vaporization of 95% of the solvent in the glue is:

Q ₂ =ΔH ₁ ×m ₁ ×95% (2)

In the formula, ΔH ₁ -the enthalpy of vaporization of the solvent, kJ/(kg·℃).

c. The minimum allowable temperature of superheated water

In the pre-coagulation process, the heat balance equation between the heat released by the superheated water down to the coagulation temperature and the sensible heat and latent heat required by the glue:

Q ₁ +Q ₂ ＝C ₃ ×8.5×1000×R×(t ₅ -t ₃ ) (3)

In the formula, C ₃ -heat capacity of water, kJ/(kg·℃);

8.5 - volume of glue solution for producing 1 ton of glue, m ³ ;

R- pre-coagulated water/glue;

t ₅ - superheated water temperature, °C.

Substituting (1) and (2) into (3) and simplifying, then:

${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="5"\; label="t"\; filenames="H2007101593540E00011.png"\; state="\{\{state\}\}">t</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 5</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="3"\; label="t"\; filenames="H2007101593540E00011.png,H2007101593540E00012.png"\; state="\{\{state\}\}">t</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="C"\; filenames="H2007101593540E00011.png,H2007101593540E00012.png"\; state="\{\{state\}\}">C</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 0.95</span>}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="3"\; label="C"\; filenames="H2007101593540E00011.png,H2007101593540E00012.png"\; state="\{\{state\}\}">C</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 8.5</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 1000</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

The condensation temperature is 98°C, and the minimum allowable temperature of the superheated water is calculated by formula (4):

When R=2, t ₅ =120.4(°C);

When R=2.5, t ₅ =115.9(°C);

When R=3, t ₅ =112.9 (°C).

The condensation temperature is 96°C, and the minimum allowable temperature of superheated water is calculated by formula (4):

When R=2, t ₅ =118.1(°C);

When R=2.5, t ₅ =113.7(°C);

When R=3, t ₅ =110.8 (°C).

②Superheated water temperature and pre-condensation temperature

In the pre-coagulation process, the heat balance equation for the heat release of superheated water and the temperature rise of the glue:

(C ₁ ×m ₁ +C ₂ ×m ₂ )×(t ₆ -t ₄ )=C ₃ ×8.5×1000×R×(t ₅ -t ₆ ) (5)

In the formula, t ₆ - pre-coagulation temperature, °C.

Substituting formula (4) into formula (5) after simplification, then:

${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="6"\; label="t"\; filenames="H2007101593540E00011.png"\; state="\{\{state\}\}">t</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 6</span>}}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="C"\; filenames="H2007101593540E00011.png,H2007101593540E00012.png"\; state="\{\{state\}\}">C</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="3"\; label="t"\; filenames="H2007101593540E00011.png,H2007101593540E00012.png"\; state="\{\{state\}\}">t</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 0.95</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="3"\; label="C"\; filenames="H2007101593540E00011.png,H2007101593540E00012.png"\; state="\{\{state\}\}">C</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 8.5</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 1000</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="C"\; filenames="H2007101593540E00011.png,H2007101593540E00012.png"\; state="\{\{state\}\}">C</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="H2007101593540E00011.png,H2007101593540E00012.png"\; state="\{\{state\}\}">m</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="3"\; label="C"\; filenames="H2007101593540E00011.png,H2007101593540E00012.png"\; state="\{\{state\}\}">C</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 8.5</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 1000</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

The condensation temperature is 98°C, and the pre-condensation temperature corresponding to the minimum allowable temperature of superheated water is calculated by formula (6):

When R=2, t ₆ =114.0(°C);

When R=2.5, t ₆ =111.2(°C);

When R=3, t ₆ =109.2 (°C).

The condensation temperature is 96°C, and the pre-condensation temperature corresponding to the minimum allowable temperature of superheated water is calculated by formula (6):

When R=2, t ₆ =113.2(°C);

When R=2.5, t ₆ =110.2(°C);

When R=3, t ₆ =108.1 (°C).

③Selection of superheated water temperature

In the pre-coagulation process, the temperature selection of the superheated water is related to the coagulation temperature and the pre-coagulation water/glue. Combining the heat balance calculation of the solvent adiabatic flash evaporation process with the production practice, the relationship curve between the minimum allowable temperature of the pre-coagulation water/glue and superheated water and the corresponding pre-coagulation temperature at different coagulation temperatures is drawn, as shown in Figure 2, X represents pre-coagulation Condensed gel/water, Y represents the temperature (°C), which provides a basis for determining the design conditions of the pre-coagulation process and selecting the conditions of the pre-coagulation process:

Curves in Figure 2: 1, 2- represent the minimum allowable temperature of superheated water and the corresponding pre-condensation temperature when the condensation temperature is 98°C; 3, 4- represent the minimum allowable temperature of superheated water and the corresponding pre-condensation temperature when the condensation temperature is 96°C the pre-condensation temperature.

It can be seen from Figure 2 that the coagulation temperature of kettle No. 1 is between 96°C and 98°C, and when the pre-coagulation water/glue ≥ 2, the temperature of the superheated water is controlled at 120°C to 125°C, and the heat carried by it will not only heat the glue to the coagulation temperature, but also Moreover, it can meet the sufficient solvent vaporization potential of glue-hot water storage in the pre-coagulation process. Therefore, the coagulation temperature of No. 1 kettle is 97±1°C, the pre-coagulation water/glue is controlled at 2.5±0.5, and the superheated water temperature is preferably 120°C-125°C.

Therefore, the coagulation process conditions can be optimized by adopting the pre-coagulation technology of the present invention. The optimized coagulation process conditions are as follows: the temperature of the 1 ^# coagulation kettle is controlled at 93°C to 99°C, and the pressure is controlled at 0.06MPa to 0.10MPa; the temperature of the 2 ^# coagulation kettle It is controlled at 96°C to 102°C, and the pressure is controlled at 0.02MPa to 0.04MPa.

Solution polymerization rubber coagulation method of the present invention is applied in butadiene rubber coagulation process, and receives better effect:

①. Under the condition of not increasing energy consumption, reduce the solvent consumption by more than 10kg/t glue. Before adopting the pre-coagulation technology, this part of the solvent is completely discharged into the atmosphere from the post-processing system;

②, coagulated colloidal particles have good drying performance, and the solvent content in the glue is reduced;

③. Reduce the corrosion of condensation and post-processing equipment and pipelines;

④. On the basis of reducing consumption, optimize the coagulation process conditions to further save energy.

The great effect of the present invention is that it is not only applicable to the coagulation process of butadiene rubber, but also generally applicable to the coagulation process of the solution-polymerization glue solution water analysis method, so that the separation of the polymer and the solvent is completed by two methods: the flash evaporation method and the water analysis method ;Adopting pre-coagulation technology is a reliable way to reduce solvent consumption without increasing energy consumption. It resolves the contradiction between energy consumption and material consumption of coagulation by water analysis method, further optimizes coagulation process conditions on the basis of reducing consumption, and achieves energy saving and emission reduction The purpose, but also to reduce equipment corrosion, eliminate potential safety hazards, and improve product quality.

Description of drawings

Figure 1 is a curve of solvent vaporization driving force and vapor consumption per ton of glue brought out of gas phase solvent under different operating conditions.

Figure 2 is the relationship curve between the minimum allowable temperature of pre-coagulation water/glue and superheated water and the corresponding pre-coagulation temperature at different coagulation temperatures.

Fig. 3 is a schematic structural view of the solution polymerization rubber coagulation device of the present invention.

Detailed ways

Below in conjunction with butadiene glue pre-coagulation embodiment further illustrate the present invention, but not limit the scope of the present invention. The 1 ^# kettle described in the embodiment is the coagulation kettle 4, and the ^2# kettle is the coagulation kettle 5, the operating pressure is gauge pressure, and the size of the colloidal particles in the post-treatment No. 1 vibrating sieve, solvent content and colloidal particles in the exhaust gas are adopted. The medium solvent content was used to evaluate the gel coagulation effect.

Example 1

According to the condensed water: glue ratio of 4.5:1, use the circulating hot water pump to pump the circulating hot water into the soda mixer according to the water: glue ratio of 3:1, and add the rest from the top of the condensation kettle;

Use steam to heat the circulating hot water of the pre-condensation system to 120°C in the steam-water mixer;

Add the dispersant to the superheated water at 0.03% of the dispersant/dry glue;

Add lye to superheated water according to the pH value of condensed hot water controlled in the range of 9.0 to 10.0;

Put the glue into the glue mixer at a flow rate of 30m ³ /h, fully mix it with superheated water in the glue mixer, spray it into the hot water at 98°C in the coagulation kettle through the pre-condensate nozzle, and spray it through the condensate nozzle The pressure is 0.4MPa～0.8MPa.

Control the condensation temperature of No. 1 kettle to 99°C and the operating pressure to 0.04MPa;

Control the condensation temperature of No. 2 kettle to 101°C and the operating pressure to 0.035MPa.

The experimental results are shown in Table 1.

Example 2

The temperature of the superheated water was 115° C., and other experimental conditions were the same as in Example 1. The experimental results are shown in Table 1.

Comparative example 1

According to the water: glue ratio of 5:1, inject the circulating hot water into the pre-condensed liquid nozzle;

Add the dispersant to the coagulation kettle at 0.05% of the dispersant/dry glue;

According to the PH value of the condensed hot water, the range of 9.0 to 10.0 is controlled to add the lye into the coagulation kettle;

According to the flow rate of 28m ³ /h, the glue liquid is poured into the pre-condensed liquid nozzle, mixed with circulating hot water and sprayed into the coagulation kettle;

Other experimental conditions are the same as in Example 1, and the experimental results are shown in Table 1.

Table 1 The influence of different process conditions on the coagulation effect

project Colloidal particle diameter/mm 1^#Contains solvent/% in vibrating sieve glue 1^#The exhaust gas of the vibrating screen contains solvent/g/m³ Example 1 2～4 0.33 13.27 Example 2 3～5 0.46 16.18 Comparative example 1 4～10 1.07 30.10

Example 3

The temperature of superheated water is 127°C; the condensation temperature of No. 1 kettle is 96°C, and the operating pressure is 0.09MPa; the condensation temperature of No. 2 kettle is 99°C, and the operating pressure is 0.04MPa. Other experimental conditions are the same as in Example 1. The experimental results are shown in Table 2.

Example 4

The temperature of the superheated water was 125°C; the degree of coagulation at No. 1 kettle was 97°C, and the operating pressure was 0.09MPa; the condensation temperature of No. 2 kettle was 99°C. Other experimental conditions were the same as in Example 1.

Example 5

The temperature of superheated water is 120°C; the condensation temperature of No. 1 kettle is 98°C, and the operating pressure is 0.08MPa; the condensation temperature of No. 2 kettle is 100°C. Other experimental conditions are the same as in Example 1.

Example 6

The temperature of superheated water is 118°C; the condensation temperature of No. 1 kettle is 99°C, and the operating pressure is 0.07MPa; the condensation temperature of No. 2 kettle is 100°C, and the operating pressure is 0.03MPa. Other experimental conditions are the same as in Example 1. The experimental results are shown in the table 2.

Example 7

The temperature of the superheated water is 115°C, the operating pressure of the No. 1 condensation kettle is 0.06MPa, the temperature is 99°C, the condensation temperature of the No. 2 kettle is 101°C, and the operating pressure of the No. 2 kettle is 0.03MPa. Other experimental conditions are the same as in Example 1. The results are shown in Table 2.

Comparative example 2

Except that the operating pressure of No. 1 coagulation kettle was 0.08 MPa, other experimental conditions were the same as those of Comparative Example 1. The experimental results are shown in Table 2.

The influence of table 2 different conditions on coagulation effect

project Colloidal particle diameter/mm 1^#Contains solvent/% in vibrating sieve glue 1^#The exhaust gas of the vibrating screen contains solvent/g/m³ Example 3 2～4 0.38 14.27 Example 4 2～4 0.42 15.18 Example 5 2～4 0.37 15.27 Example 6 2～4 0.39 16.10 Example 7 3～5 0.47 18.16 Comparative example 2 4～18 1.39 46.26

As can be seen from the above examples and comparative examples, the method of the present invention can reduce the particle size of the coagulated colloidal particles, increase the vaporization rate of the solvent, and reduce solvent consumption no matter in the isobaric coagulation process or the differential pressure coagulation process; Simultaneously, it can be seen that by adopting the method of the present invention, increasing the temperature of the superheated water can reduce the coagulation temperature or/and increase the coagulation operation pressure, further saving energy on the basis of reducing consumption, and fully achieving the purpose of energy saving and emission reduction of the present invention.

Example 8

Solution polymerized rubber coagulation method of the present invention is realized through the following steps:

a. Heat water to 115℃～130℃ to make superheated water, and add polycarboxylate sodium dispersant and sodium hydroxide lye, the amount of dispersant added is 1×10 ^-4 ～5×10 of the dry glue mass ^-4 , the amount of lye added is between 9 and 10 to control the PH value of the condensed hot water;

b. Fully mix the glue solution with the superheated aqueous solution prepared in step a to obtain a heterogeneous mixture of glue solution-hot water at 113°C to 125°C; the mixing volume ratio of glue solution and superheated water is 1:2-3;

c. Spray the glue-hot water heterogeneous mixture into the coagulation kettle with 93-100°C hot water, and complete the pre-coagulation process of the glue;

d. The pre-coagulated glue is kept under stirring in the coagulation tank and the residence time is controlled to be 40-50 minutes, that is to say, the coagulation process of the water analysis method is completed.

Example 9

The solution-polymerized rubber coagulation device of the present invention is composed of a steam-water mixer 1, a glue mixer 2, a pre-condensed liquid nozzle 3 and coagulation kettles 4 and 5. The outlet pipeline of the steam-water mixer 1 is connected to the pipeline of the glue mixer 2, the outlet of the glue mixer 2 is connected to the pre-condensed liquid nozzle 3, the outlet of the pre-condensed liquid nozzle 3 is placed in the coagulation kettle 4, and the outlet of the coagulation kettle 4 The pipeline is connected with the coagulation kettle 5 through the pump 6. Among them, there are circulating water inlet a and steam inlet b on the steam-water mixer 1, and there are dispersant inlet c, lye inlet d and glue inlet e on the outlet pipeline; there are circulating water inlet f and steam inlet f on the coagulation kettle 4 Inlet g; there are steam inlet i, gas phase precipitate outlet j and colloidal water outlet k on the coagulation kettle 5.

Claims (4)

1. method for agglomerating solution-polymerized rubber, its feature comprises following operation steps:

A, heat water to 115 ℃～130 ℃ and make superheated water, and add polycarboxylic acid sodium dispersion agent and sodium hydroxide lye, the dispersion agent add-on is 1 * 10 of a dry glue quality ^-4～5 * 10 ^-4, alkali lye add-on to the pH value of control cohesion hot water is between 9～10;

B, with the superheated water solution thorough mixing that glue and a step make, obtain the non-homogeneous mixture of 113 ℃～125 ℃ of glue-hot water;

C, glue-hot water non-homogeneous mixture sprayed be injected with in the cohesion still of 93～100 ℃ of hot water, promptly finished the pre-agglomeration process of glue;

The control residence time was 40～50 minutes under glue after d, the pre-cohesion continued to stir in the cohesion still, promptly finished the elutriation method agglomeration process.

2. method for agglomerating solution-polymerized rubber as claimed in claim 1 is characterized in that the mixed volume ratio of glue and superheated water is 1: 2～3 in the b step.

3. method for agglomerating solution-polymerized rubber as claimed in claim 1 is characterized in that the spraying pressure in the c step is 0.4MPa～0.8MPa.

4. described method for agglomerating solution-polymerized rubber as claimed in claim 1 is characterized in that in the d step elutriation method agglomeration process that for the first time condensation temperature is controlled at 93 ℃～99 ℃, pressure-controlling at 0.06MPa～0.10MPa; For the second time condensation temperature is controlled at 96 ℃～102 ℃, pressure-controlling at 0.02MPa～0.04MPa.

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