A loop reactor (LR) is an N-unit system composed of a loop with gradually shifted inlet/outlet ports. This system was shown in our previous study [Sheintuch M., Nekhamkina O., 2005. The asymptotes of loop reactors. A.I.Ch.E. Journal 51, 224-234] to admit an asymptotic model for a loop of a fixed length with N --> infinity. Both the finite-unit and the asymptotic model exhibit a quasi-frozen or a frozen rotating pulse (FP) solution, respectively, within a certain domain of parameters that becomes narrower as feed concentration declines. In the present paper we derive approximate solutions of the ignited pulse properties in an LR as a function of the external forcing (switching) rate. Analysis of these solutions enable us to determine the maximal temperature in the system, as well as the boundaries of the FP domain. For the optimal solution we determine the maximal temperature and conversion dependencies on the reactor length and on N. ne approximate solutions are verified by comparison with direct simulations of the asymptotic model and a good agreement was found. The obtained results can be successfully used for prediction of the finite unit LR. (C) 2007 Elsevier Ltd. All rights reserved.