Study of Electric Field Impact on Crystallization in Tunnel Drainage Pipes in Hard Water Area

Table 6

Summary of total crystal amount in the pipes within respective periods.

Electric field pattern	Field direction	Total crystal amount in pipes (g)
Running time		10 d	20 d	30 d	40 d	50 d
Circumferential electric field	Group A	3.64	4.96	6.51	7.77	8.96
	Group B	3.01	4.49	5.85	7.07	7.94
Parallel plate electric field	Group C	5.66	7.38	8.77	8.54	7.01
	Group D	5.14	6.96	8.13	8.84	7.55
Comparison group		2.77	5.02	6.51	7.75	7.47