Sulphonation Reactor: Sulfonator is the core equipment of a sulphonation plant, WEIXIAN Reactor adopts multi-tube falling film type. The organic raw materials entrances are between the Tube-sheet 1&2, the organic raw materials in the reaction tube form a uniform film, and reacts with SO3 gas (2.5- 7%). The reaction emits a large amount of heat which is removed by heat exchange of chilling water or cooling water in the shell process.   There are currently mainly 5 types of organic raw materials, which are: 1.  LAB/ alkyl benzene for LABSA 2.  AEO1, AEO2 or AEO3/ Fatty alcohol ether for SLES- 1EO/2EO/3EO 3.  AO/ α olefin for AOS 4.  FA/ fatty alcohol for SLS 5.  HAB/heavy alkyl benzene for HABSA The capacity range of WEIXIAN sulphonators is from 1 tube to 240 tubes (1 - 10t/h). So far, WEIXIAN has supplied hundreds reactors, including two world’s largest 7.5t/h 180-tube reactors.  The technical advantages of WEIXIAN sulfonator: Ø    The organic material distribution system 1.  The reactor calibration can easily reach ±1.5% deviation, which makes the first start up much simpler and results in better product quality. 2.  The distribution heads and nozzles are machined in a single clamping process in a CNC machining center to ensure that the tolerance of the main dimensions reaches ±0.01mm. Ø    High finish degree of each reaction tube surface Special manufacturing processes are applied, the reaction tubes are processed under a 1040℃ vacuum condition to remove inter- molecular stress after high-precision cold rolling , which makes sure the inner and outer surfaces’ finish degree of each reaction tube reaches Level Ra0.4 (like mirror) with high consistency, benefited from perfect surface finish, consistent molar ratio of the entire reaction can be ensured and side reaction can be reduced greatly, this is crucial in regards of minimizing dioxane content in SLES and reducing the organic acid content in exhaust gas. In addition, the tolerance of the inner diameter and outer diameter of the reaction tube is controlled within the range of ±0.04mm. Ø  Welding points and Pre-factory testing The welding points between the Reaction Tube and the Distribution Head are moved up to skip the reaction initial part, and butt welding is changed to fillet welding. Therefore there is no weld on the entire 6-meter Reaction Tube, shallow leakage at reaction initial part can be avoided, and the reliability is greatly improved. Each reaction tube is subjected to 0.6Mpa water pressure test and endoscopic probe to check the weld molding and inner tube precision before leaving the factory. Ø  Concentricity of the three tube sheets Three pieces of tube sheets must be machined with the same coordinates in the machining center. The concentricity tolerance of the processed pipe holes reaches ±0.01mm. After the completion of manufacturing, the three pieces of tube sheets are stacked and fixed together according to the installation position, and checked hole by hole with the concentricity deviation of less than ±0.02 inspection mandrel. Ø  Reliability of multiple seals in the sulfonator 1.    Cooling/chilling water sealing in shell process: cooling/chilling water is fed into two inlets and discharged through three outlets after heat exchanging; the upper section is strictly sealed to ensure that the upper section circulates the chilled water (15°C) separately without leakage. This is especially important in the production of AOS. 2.     The head of sulfonator adopts two-way sealing of SO3 sealing and organic material sealing: the compression screw head of the tube sheet 1 adopts a combination of screw head + three combination gaskets to form a reliable two-way sealing, which realizes 100% reliable isolation of oleum and elimination of rusting and leakage. 3.      Distribution head and shell process cooling water sealing: With the use of new sealing structure greatly improves the pressure resistance of the shell process, shell process test pressure reaches 0.6Mpa or more. All sealing parts are made of special fluorine rubber O-ring, with 100% sealing efficiency and lifetime without replacement. 4.      Lower section of reaction tube and shell process cooling water sealing: adopts Viton O-ring sealing, 100% sealing efficiency, lifetime without replacement.   Other advantages: 1.      Long extended washing interval: continuous production of LABSA can reach more than 40 days, more than 3 months for SLES production and more than 25 days for AOS production. 2.      Easy calibration of reactor: ±1.5% deviation of flow rate at the first start-up, and the range of gasket replacement is 1.8-2.2mm (base thickness is 2mm), which ensures the quality of sulfonated products and extends the cleaning cycle of the reactor. 3.     Yield Flexibility: Capacity adjustment range 55% ~ 115% for LABSA production; Capacity adjustment range 80% ~ 140% for SLES 70% production.    

  1. The sealing type of compression nut on reactor tube sheet 1:  increasing one V type Teflon gasket and Fluororubber O ring to isolate the leakage of SO3 and organic acid, so that no rust or leakage happen. The reliability is better than Italy reactor.(as below photo No.1 and 2) 2. The No.3 of photo change to flat Teflon gasket(Italy is two way gasket): This will bring better seal performance and can reduce 50% force to tube sheet 1, so that the transformation would greatly reduced and the organic material would not leak into reactor tube. The reactor washing times and operation period is highly improved.   3. Compared with Italian reactor, the thickness of WEIXIAN tube sheet 1/2/3 is 16% more and organic material chamber is 25% higher, that can make the transformation of tube sheet close to zero and distribution of organic material becomes more equal, this makes big capacity reactor be possible.   4. The welding point between reactor tube and distributor move up to avoid reaction segment and change from butt welding to fillet welding, so that there is no welding joint in reactor tube inside, compared with Italy reactor, WEIXIAN will not have leakage in this part, the reliability improved greatly.   5. The size and angle optimation of reactor tube, distributor and nozzle, make sure the organic material pressure drop 13% more when passing through gap , so the self balance performance is improved accordingly compared with Italy reactor, especially for α-olefin sulfonation.   6. The special manufacture process of reactor tube (without polishing) ,that can make sure the rough degree of tube inside and outside and each tube are highly consistency( Ra0.4), so the dioxane content will significantly superior to Italy’s when produce SLES.   7. One Fluororubber O ring and three Teflon gaskets were adopted between shell side and tube side of tube sheet 3, so WEIXIAN reactor will never leakage, and the cooling water can recycle under 0.5mpa pressure(pressure test is under 0.6mpa)   8. The material of reactor tube, distributor and nozzle are all booked from Bao steel (The biggest and best steel factory in china) and we ordered at least 5 tons one batch, so that the material source can traceable and the quality can be guaranteed.   9. WEIXIAN engineer will full time supervise the testing and assemble of reactor and its components. That will guarantee the fabrication and manufacturing quality.   Equipment Link: https://www.njweixian.com/sulphonationsulphation-reactor  

Innovation and development of SO3 multitube film sulphonation reactor of Weixian Shumin Li, Chen Li, Gongjian Cai (WEIXIAN NANJING SCIENCE TECHNOLOGY CORP. LTD. Jiangsu Nanjing 201142)   Abstract: this article introduces the innovation and experiences of a type of SO3 multitube film sulphonation reactor in its design and manufacturing. Mainly explains the relations among design and manufacturing of reactor’s main parts, sulphonation/sulphoacid reaction, and quality control, production stability and equipment reliability. Concludes that WEIXIAN’s SO3 multitube film sulphonation reactor is superior to similar Italian equipment, in term of key performance and reliability. Key words: SO3 film sulphonation, multitube film sulphonation reactor, innovation, development     Preface： In March 1995, WEIXIAN independently designed and manufactured domestically a 6-tube multitube film sulphonation pilot plant. Its capacity was 250kg/h, and tested LAB, BAB, HAB, FA, AEO and α-olephin as raw material for batch OEM produce. Next, we will introduce WEIXIAN’s innovation and development in regards of SO3 multitube film sulphonation reactor.   1. The reaction tubes of SO3 multitube film sulphonation reactor Since 1995, the first 6-tube film reactor, WEIXIAN always keep improving and perfecting the design and manufacturing process of sulphonation reactor. Basically, the length, internal diameter and thickness influence the heat transfer, material transfer and reaction speed. By countless times experiments, optimal data have been obtained.   The internal tolerance and surface finish difference of reactor tube not only influence heat transfer and material transfer, but also influence differential SO3 and organic material mole ratio, which is crucial for dioxane control when producing SLES. So, while we manufacturing one batch of reaction tubes (normally 1000 tube/batch), we make sure using one mold for the cold working, which ensure each tube’s internal and external diameter tolerance is consistent.   Then the reaction tubes will be putt into a 1040℃ furnace, for removing the stress between molecules due to the cold working. In order to keep the surface finish degree (like mirror) benefit from cold working, there should be no oxygen under this 1040 ℃ condition, which is the most advanced oxygen isolating stress relieving technology. We abandoned the artificial sanding method which can’t make the surface as smooth as mirror. With perfect surface finish degree, side reaction can be reduced effectively, it is crucial in regards of decreasing dioxane content in SLES.   2. Distribution head and SO3 nozzle Please see Drawing 1 for distribution head and SO3 nozzle.   There are special designs for distribution head. The sealing between distribution head and shell side cooling water is able to accept enough pressing force, so that reactor shell can bare pressure up to 0.6 mpa, while the pressure of returning water which enters reactor is normally ≤0.05 mpa. That is why the recycle cooling water is able to carry with higher pressure.   In terms of distribution head and SO3 nozzle processing, we also ensure the consistency, and simplify the first start-up commissioning (see diagram 1 and 2) and extend the interval of reactor cleanings. Especially while producing AOS, the optimizations decrease the lower operation limit of reactor. Because of little feeding volume of α-olephin, the distributing and balancing ability of reactor’s liquid film have to be increased while operating under lower operation limit. Diagram 1  Zhitong system 37-tube reactor first calibration flow rate deviation distribution No. Flow rate deviation Tube quantity Gasket thickness 1 Less than ±1.5％ 19 tubes 2.00mm 2 ±1.5％～±2.5％ 13 tubes 2.00mm 3 ＋3.7％ 1 tubes 2.00mm 4 －3.6％ 1 tubes 2.00mm 5 －5.2％ 1 tubes 2.00mm 6 ＋8.8％ 1 tubes 2.00mm 7 －6.5％ 1 tubes 2.00mm   Diagram 2  Zhitong system 90-tube reactor first calibration flow rate deviation distribution No. Flow rate deviation Tube quantity Gasket thickness 1 Less than ±1.5％ 33 tubes 2.00mm 2 ±1.5％～±2.5％ 31 tubes 2.00mm 3 ±2.5％～±3.0％ 13 tubes 2.00mm 4 ±3.0％～±3.5％ 8 tubes 2.00mm 5 －4.7％ 1 tubes 2.00mm 6 ＋5.6％ 1 tubes 2.00mm 7 －8.4％ 1 tubes 2.00mm 8 ＋7.3％ 1 tubes 2.00mm 9 ＋8.9％ 1 tubes 2.00mm   As you can see from the diagrams above, the consistent processing of distribution heads and nozzles minimize each reaction tube’s original flow distributing tolerance, and make adjustment easier.   3. Tube sheet and organic material distribution chamber Regarding the tube sheets of 120/144/180 tube reactor, 25% thickness is increased. So that rigidity is increased, tube sheet would not be transformed much and the tightness of SO3 sealing would be improved.   Also, The height of organic distribution chamber is increased by 8-12 mm (see Drawing 1). It is beneficial for large capacity reactor’s organic material distributing.                                Drawing 1                                                Drawing 2     4. The sealing format between SO3 and organic material The increase of organic material distribution chamber height and improvement of shell pressure bearing ability are benefited from the special design of sealing format between SO3 compression nut, tube sheet 1 and tube sheet 2. As Drawing 1, at the top is the first seal of tube sheet 1, that consists of a V-shape gasket (Creep-resistant special teflon) and a O-shape gasket (Anti-oleum fluororubber). That means double safety, each of them ensure 100% isolate SO3 from tube sheet 1’ screw thread and organic material distribution chamber. Therefore, the sealing is very reliable and solved the headache problem that the compression nuts sealing of Italian’s reactor is unreliable, sometimes get rusted and can’t open.   As shown in Drawing 1, the second seal is Z-shape creep-resistant Polytetrafluoroethylene plano-concave gasket, which isolates organic material from SO3 in the nozzle inner wall. This special design is efficient and the locking torque for compression screw heads is only the half of two-direction sealing (which is Ballestra’s, Drawing 2 shows the structure of Ballestra’s distribution head). With only half locking torque, the Tubesheet 1 will has less deformation, especially for big capacity reactors. It solves the problem that after tightening all compression screw heads, you may find the first screw head get loosen again. That consolidates the foundation of design and manufacturing of 180, 192 or even more tube reactors.