Heating tape

All glassware is oven-dried. The dropping funnel is wrapped with heating tape, and a thermometer is inserted between the funnel and the tape. 

Distillation was performed using a 30-cm. vacuum-jacketed column wrapped with heating tape and containing a spiral of wire (Nichrome or Chromel) in the center bore. The receiver portion of the assembly contained two flasks, one to collect the material that distilled below 72° and another for the desired fraction. An air-cooled condenser was used with this apparatus, since water cooling often causes the product to solidify and clog the condenser tube. 

Half ester, of malonic acid, 37, 34 Heating tape, 37, 4, 68 Heat transfer salt, 37, 49... 

It is important that sufficient time be allowed for proper partitioning between the phases. The heating tape maintains the temperature in the desired range, preventing the precipitation of solids and allowing for better separation. The phases should be allowed to separate for at least 15 min. If a small amount of solids is observed, this should not interfere with the separation and the solids may be discarded with the aqueous phase. 

The unpacked column should be wrapped with a heating tape, or Nichrome heating wire, and kept at ca. 110° throughout the decomposition. 

The interface consists of (a) the nebulizer (b) the chamber (c) the membrane separator and (d) the torch. Organic solutions are fed to the nebuhzer via a peristaltic pump and the aerosol chamber is heated by a 2S0 W heating tape around the chamber. The membranes used are made from siHcone rubber and this is supported by high density polyethylene supports. A vacuum pump provides the vacuum on the membrane to remove the solvent vapour. 

Often it is necessary to heat transfer lines to ensure that products do not gel in the line during cold weather. Both electrical heating and steam heating can be used to trace lines. Only explosion proof electrical heat tape and thermostats can be used on fuel systems. Immersion heaters are not recommended for fuel and fuel additive applications. 

Fig. 3.13. The parts of this diagram above and below 7 are not drawn to the same scale. The solvent supply system above tap 7 is the same as that shown in Fig. 2.14 and explained there. A are the coils of a heating tape, is a stirring bar to agitate the CaHj, C.

Apply full heat to the liquid bath and when the temperature of the sample reaches 190 F (87.S C), adjust the heat input so that the temp of the sample increases at a rate of 2 tO. 5 F (11 0.25 C)/min Note 6 The heaters on some testers do not have sufficient capacity to maintain the proper rate of heating when the temperature approaches 250 F (121.1 C) or above. The heat input to the liquid bath may be increased if necessary by using a variable transformer to increase the voltage on the heater or by wrapping the bath with electrical heating tape. The application of suitable insulation to the outdide of the bath to prevent heat loss is also permissible. The important factor is to maintain the rate of temp increase of the sample at 2i 0.5F (1—0.25 C)/min... 

Temperature control is important for the success of the reaction. The internal temperature should be monitored, and the temperature should be held around 65°C. The submitters found that when the autoclave (Parr 4751) is heated with heating tape... 

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