Agitation jacket vessels

A solution of NaOH in water is prepared by diluting a concentrated solution in an agitated, jacketed, vessel. The strength of the concentrated solution is 50 per cent w/w and 2500 kg of 5 per cent w/w solution is required per batch. Calculate the heat removed by the cooling water if the solution is to be discharged at a temperature of 25°C. The temperature of the solutions fed to the vessel can be taken to be 25°C. 

Reactors, columns and other vessels are usually designed as special items for a given project. In particular, reactor designs are usually unique, except where more or less standard equipment is used such as an agitated, jacketed, vessel. 

Agitated jacketed vessel the main resistance to heat transfer is located at the wall, where there is practically no resistance to heat transfer inside the reaction mass. Due to agitation, there is no temperature gradient in the reactor contents. Only the film near the wall presents a resistance. The same happens outside the reactor in its jacket, where the external film presents a resistance. The wall itself also presents a resistance. In summary, the resistance against heat transfer is located at the wall. 

Empirical dimensionless group correlations have been used in the scale-up process. In particular, the correlation for the inside film heat transfer coefficient for agitated, jacketed vessels has been employed for the scale-up to a larger vessel. Reaction calorimeters are often used to give some indication of heat transfer coefficients compared to water in the same unit. Correlation for plant heat transfer is of the general form... 

A solution of NaOH in water is prepared by diluting a concentrated solution in an agitated, jacketed vessel. The strength of the concentrated solution is 50% w/w, and... 

A commonly used method of determining numerical values for the inside film heat transfer coefficient for agitated, jacketed vessels is the Wilson plot. A Wilson plot (Figure 4.19) is essentially a linear regression through data points, which represent the reciprocal overall heat transfer coefficient against the reciprocal agitation speed ... 

Brown. R.W., Scott, M.A. and Toyne, C. Tram. Inst. Chem. Eng. 25 (1947) 181. An investigation of heat transfer in agitated jacketed cast iron vessels. 

Equipment, The reactor was 1.523 liter, 316 stainless steel cylindrical, jacketed vessel equipped with two multiblade, paddle-type agitators. Tracer studies showed the reactor was well-mixed. A thermocouple measured temperature and was recorded continuously. Feed tanks, tubing, pumps and valves were made of stainless steel and had teflon seals. 

Figure 12.72. Jacketed vessels, (a) Spirally baffled jacket (b) Dimple jacket (c) Half-pipe jacket (d) Agitation...

They were also used as colloiding agents for NC(Refs 2, 3 4) employed in the manuf of smokeless propellants. For instance, one of the US shot-gun propellants was prepd by agitating at RT(in a jacketed vessel) a pulped, wet NCfcontg 5% Ba nitrate 2% K nitrate) with an emulsion of amyl acetate and waterfcontg some Ba- and K nitrate). 

Sealed containers of aqueous solutions, suspensions, and other liquids can be processed through steam sterilizers as well. These liquids might be used in formulation or cleaning procedures, and sterilization in this manner may be more efficient and more reliable than sterilizing filtration. Larger volumes of aqueous liquids are often sterilized in bulk using a jacketed and agitated pressure vessel (the vessel is usually rated for full vacuum as well). 

In summary, because of the uncertain effect of system geometry, it is recommended that for purposes of estimation or design Table VI should be used to select a correlation which was developed from tests on a system as similar as possible to the one under consideration. For jacketed vessels using paddle agitators the correlation of Pursell is indicated. For other jacketed vessels or for the case of helical coils... 

Fluid Inside Fluid In Jacket Vessel Wall Material Agitation u... 

Step 9. The solution of sodium chloride and sodium carbonate leaving the waste liquor neutralizer is combined with the waste liquor from the product centrifuge (Step 12). The combined solution is split into two streams. One goes to a waste treatment facility, and the other goes to the NaOH makeup tank, an agitated jacketed batch vessel. Solid pellets of sodium hydroxide are added to this tank to bring the NaOH concentration... 

Step 11. The sodium bicarbonate solution fed to the resin neutralizer (Step 10) is produced by dissolving NaHCO powder from 25-kg bags in clean water in the NaHCOa makeup tank, an agitated batch vessel. This makeup tank is not jacketed like the NaOH makeup tank, as the heat of solution of sodium bicarbonate is low enough for the heat generated in the tank to be neglected. Batches of solution are pumped from the makeup tank to the NaHCOj feed drum, and solution is pumped continuously from the feed drum to the resin neutralizer. 

The preparation of dichloroethyl sulphide by this method was carried out in a cylindrical vessel of sheet steel or cast-iron, lead-lined and jacketed, of about 100 cm. diameter and 130 cm. in height, fitted with an agitator. This vessel has a lid through which a pipe passes to within a short distance of the bottom in order to introduce the ethylene. 

The solid wall can be the wall of the evaporator itself, as in jacketed evaporators. The area available for heat transfer in jacketed vessels, however, is quite limited. Jacketed vessels frequently incorporate some sort of internal agitator. 

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