Agitation nozzles, jackets

Based on initial heat flow calorimetry studies, a process development engineer must choose the appropriate reactor vessels for pilot plant studies. A pilot plant typically has vessels that range from 80 to 5000 L, some constructed of alloy and others that are glass lined. In addition some vessels may have half-pipe coils for heat transfer, while others have jackets with agitation nozzles. A process drawing for a typical glass-lined vessel is shown in Figure 4. In Sections 3.1.4.1 and 3.1.4.2 we review fundamental heat transfer relationships in order to predict overall heat transfer coefficients. In Section 3.1.4.3 we review experimental techniques to estimate heat transfer coefficients in process vessels. 

Jacket-Side Coefficient Here the calculations are shown for a jacket equipped with agitation nozzles that greatly increase the jacket fluid velocity. The jacket swirl velocity v, is calculated (iteratively) from the nonlinear algebraic relationship [17]... 

Chapter 7, Reactor Design, discusses continuous and batch stirred-tank reactors and die packed-bed catalytic reactor, which are frequently used. Heat exchangers for stirred-tank reactors described are the simple jacket, simple jacket with a spiral baffle, simple jacket with agitation nozzles, partial pipe-coil jacket, dimple jacket, and the internal pipe coil. The amount of heat removed or added determines what jacket is selected. Other topics discussed are jacket pressure drop and mechanical considerations. Chapter 7 also describes methods for removing or adding heat in packed-bed catalytic reactors. Also considered are flow distribution methods to approach plug flow in packed beds. 

Plain Jacket with Agitation Nozzles Source Adapted from Reference 7.10... 

Installation of agitating nozzles is recommended if sensible liquid heating or cooling is to be used with plain jackets. Nozzles produce liquid jets directing the inlet jacket fluid in a spiral fashion into the jacket. This increases the effective velocity and turbulence level. Vendors have information dealing with their performance and installation. 

Bondi [82] proposes the following equations for sensible fluid in plain jacket with no agitating nozzles. 

The outside coefficient, ho, is quite low for water in a simple open jacket. It can be increased by using agitation nozzles, a spiral baffle in the jacket, or a half-pipe coil welded to the tank [1,2]. The wall resistance is usually negligible for a steel tank, but it may be significant for a thick stainless steel wall or for a glass-lined reactor. 

This family of filters consist of a vertical pressure vessel with a horizontal filter plate at the bottom. The filtrate from this equipment flows out a nozzle on the bottom of the filter. These devises are usually used for slurries where large amounts of solids are being collected. Variations of this equipment include equipment with removable lower heads for easy cake removal, ability to pressure or vacuum filter, ability to wash the filter cake, an agitator to break-up and rewash the filter cake, and heating or cooling jackets for the whole vessel. The Nutsche filter is the industrial version of the well known laboratory scale Buchner Funnel with the exception that it is designed to operate under either on vacuum or pressure. 

The crystallizer was an agitated vessel with an Inside diameter of 9.0 cm and a volume of about 1 1. It was equlppet with four vertical baffles, a water jacket to keep the solution temperature constant, and a nozzle through which nitrogen gas was Introduced In several experiments to suspend a speed crystal more effectively In the solution. Agitation was accomplished with a 5.0 cm stainless steel marine propeller having three blades driven by a variable speed motor. 

The mixer is loaded with nonyltrichlorosilane from batch box 8, the agitator is switched on and the mixture is agitated for 15-20 minutes. From container 4 butyl alcohol is sent into batch box 1. The ring jackets of tower 3 are filled with vapour when the temperatue in the tower rises to 75-80 °C, the toluene solution of nonyltrichlorosilane is sent from mixer 9 and butyl alcohol is sent from batch box 1 through fluoroplast nozzles in the bottom part of the tower. The solution of nonyltrichlorosilane and butyl alcohol is sent in the mole ratio of 1 1.5. The product of partial etherification is continuously withdrawn from the top of the tower through a run-down box into collector 10. 

Cost of kneaders. Price includes machine, jacket, gear reducer and drive, cover, nozzles, and agitator. Motor and starter are not included in purchase price. 

A jacketed stainless steel vessel without any sharp comers. Sharp comers facilitate growth/fouling, which is difficult to remove. Standard flanged dish ends are used as a cover with provision for agitation assembly, feed/outlet nozzles, etc. as per the requirement of the process planned. The relevant details are provided in Section 7B.16. 

The details of the design of the reactor will be calculated for each process and these will dictate the capacity of the vessel, the size of the cooling/heating jacket or coil, the speed and type of agitator and baffle, the type of agitator gland, and the size of its drive motor the position, range, and sensitivity of the instruments the size of inlet and outlet nozzles, and the type of valves used in these nozzles. Typical reactors are shown in Fig. 3.2. 

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