Helical baffle heat exchanger without central tube

The invention provides a spiral baffle heat exchanger without a central tube, which comprises a shell assembly, the shell assembly comprises a middle shell, two sides of the middle shell are respectively communicated with a left shell and a right shell, the inner diameter of the left shell and the inner diameter of the right shell are larger than that of the middle shell, and guide cylinders with the same inner diameter as that of the middle shell are respectively fixed in the left shell and the right shell. Medium flow in the shell assembly is complete spiral plunger flow, no dead angle exists in the whole process, the shell pass heat transfer coefficient can be greatly increased, scaling on the surfaces of heat exchange pipes can be reduced, long-acting operation of the heat exchanger is guaranteed, the service life of the heat exchanger is prolonged, and meanwhile it is avoided that the service life of the heat exchanger is shortened due to under-scaling corrosion; meanwhile, the number of the heat exchang