Kettle preparation

Both novolaks and resols are prepared in similar equipment, shown dia-grammatically in Figure 23.16. The resin kettle may be constructed from copper, nickel or stainless steel where novolaks are being manufactured. Stainless steel may also be used for resols but where colour formation is unimportant the cheaper mild steel may be used. 

Figure 23.16. Diagrammatic representation of resin kettle and associated equipment used for the preparation of phenolic resins. (After Whitehouse, Pritchett and Barnett )...

In the catalyst preparation area where the fire occurred, aluminum alkyl and isopentane are mixed in a batch blending operation in three 8000-gallon kettles. The flow rates of components are regulated by an operator at the control room. Temperature, pressure, and liquid level within the kettles are monitored by the control room operator. The formulated catalyst is stored in four 12,000-gallon vertical storage tanks within this process unit. Aluminum alkyl is a pyrophoric material and isopentane is extremely flammable. Each vessel was insulated and equipped with a relief valve sized for external fire. 

On August 1, 2001 at 10 30 A.M., a control room operator remotely started the feeds to Kettle No. 3 in the catalyst preparation area. The normal procedure was to fill the kettle to approximately 80%, but Kettle No. 3 was apparently completely filled this time. The level indicator showed a high level, but the alarm did not sound. (The alarm was later found to be inhibited.) A high-pressure alarm for this vessel was acknowledged at 11 03 A.M. by the control room operator. At 11 00 A.M., a severe thunderstorm had started and within 5 minutes caused a power outage throughout the immediate vicinity. The ambient temperature was about 83°F and winds were from the northwest at about 3 mph. 

Polymer preparations should not be scaled up without a careful review and a gradual scaleup to check exotherms. This will determine the proper equipment and cooling needed before starting. All glassware should be free of cracks, and defects before using. In most cases, ordinary laboratory glassware may be used, but resin kettles are sometimes desirable on a larger scale operation. 

Diethyl sulfate can be prepared by a variety of methods. When ethyl hydrogen sulfate is heated with sodium chloride to 80°C, hydrogen chloride is liberated. The resulting reaction mixture is then distilled at 1.33—2.00 kPa (10—15 mm Hg) at a maximum kettle temperature of 190°C to give diethyl sulfate in 90% yield (95). 

As a rule fusible mixtures are prepared in metallic kettles heated with steam or water jackets and fitted with stirrers, which are emptied either by tilting or through a valve placed in the bottom of the vessel. 

The preparation of S-type mixtures. The following description of the preparation of S-16 mixture is provided as an example. In a stainless steel kettle of 500 kg capacity equipped with a stirrer and steam-heated to 118°C, 250 kg of the mixture is prepared by pouring in the ingredients, in the following sequence ... 

ShelI l..oadi ng with 80/20 Amatol, Part of the mixt maintained in the kettle at 90—95° (See above under Preparation) was transferred to the hopper of an extruder which was provided with a stirrer and jacket heated with steam at 3—5 lbs pressure. The extruding machine consisted of a steel tube in which a worm screw rotated slowly. This... 

Preparation of 67/33 Baratol. The approx wt of Ba nitrate, preheated to ca 90°, is added to molten TNT contained in a melting kettle equipped with an agitator. Mixing is continued until a uniform mass is obtained. Then the melt is cooled slightly while the agitation is continued and is loaded into ammo at the lowest temp at which it will flow freeIy(Ref 4)... 

Preparation. In the laboratory prepn of Compo-sition C-4, dry RDX is added to a petroleum ether soln of di(2-ethylhexyl)sebacate, polyisobutylene SAE 10 engine oil. The solvent is evaporated and the residue worked by hand into a homogenous dough-like mass. Since the use of a volatile flammable solv is undesirable in plant production, a solventless process was developed. In the plant process two different granulations of RDX are used 61 parts of Class (or Class B) 30 parts of Class 3 (See description of RDX classes under Cyclo-trimechylenetrinitramine in this vol of Encyclopedia). The water-wet mixture of both is placed in a stainless steel mixing kettle and 9 parts of "polyisobutylene" binder are added. 

The prepared maple sawdust is made by cooking with miner s wax, 10 pounds of sawdust to 1 ounce of wax, in a steam-jacketed kettle. The mixture is tamped dry into a paper tube, 7/ inch in external diameter, 1/32 inch wall, and burns at the rate of about 1 inch per minute. The fusee is supplied at its base with a pointed piece of wood or iron for setting it up in the ground, and it burns best when set at an angle of about 45°. In order to insure certain ignition, the top of the charge is covered with a primer or starting fire, loaded while moistened with... 

The oiganic and aqueous phases are prepared in separate tanks before transferring to the reaction kettle. In the manufacture of a styrenic copolymer, predetermined amounts of styrene (1) and divinylbenzene (2) are mixed together in the oiganic phase tank. Styrene is the principal constituent, and is usually about 90—95 wt % of the formulation. The other 5—10% is DVB. It is required to link chains of linear polystyrene together as polymerization proceeds. DVB is referred to as a cross-linker. Without it, functionalized polystyrene would be much too soluble to perform as an ion-exchange resin. Ethylene—methacrylate [97-90-5], and to a lesser degree trivinylbenzene [1522-25-2], are occasionally used as substitutes for DVB. 

The aqueous phase into which the monomer mix is dispersed is also prepared in a separate tank before transferring to the copolymerization kettle. It contains a catalyst, such as benzoyl peroxide [94-56-0], to initiate and sustain the polymerization reaction, and chemicals that aid in stabilizing the emulsion after the desired degree of dispersion is achieved. Careful adherence to predetermined reaction time and temperature profiles for each copolymer formulation is necessary to assure good physical durability of the final ion-exchange product. 

The food preparation area of approximately 6000 sq. feet is fully equipped with steam kettles, rotisserie, grills, deep fat fryers, retort, ovens, smoke house, blast freezer, and storage boxes (Figure 14). 

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