Helical Rotor Flow Meter

Principle and Structure

The helical rotor flowmeter consists of a flow transmitter and a counter. The main part of the transmitter is composed of a metering chamber equipped with a pair of special-tooth helical rotors and a sealed coupling. The counting mechanism includes a reduction gear unit, an accuracy adjustment mechanism, and the counter comprises a digit wheel totalizer and an electric pulse transmitter, among others.

The metering chamber mainly consists of a pair of special rotors and cover plates that form sealed cavities, which serve as the flow metering units. The rotors are driven by the pressure difference between the inlet and outlet of the flowmeter, causing them to rotate, thereby continuously metering the liquid from the inlet through the sealed cavities and delivering it to the outlet. The liquid volume displaced per revolution is eight times the volume of one sealed cavity (as shown in the figure). The total number of rotor revolutions and the rotational speed are transmitted to the counting mechanism via a sealed coupling, where a pointer display and a digit wheel totalizer indicate the total liquid volume passing through the pipeline. A pulse transmitter can also be installed in the counting mechanism, converting the flowmeter into a pulse-output type. When used with our electronic display instruments, it enables remote automation measurement and control (including batching, totalizing, instantaneous flow, etc.).

Flow range (m³/h) (accuracy class 0.5)

型号	口径	粘度mPa.s
		0.3~0.8	0.8~2	2~15	15~400	400~1000	1000~2000	2000~3500
		汽油	煤油	柴油、机油	重油	高粘度液体
LLT-0252	25	3~9	1.5~10	1~10	1~10	1~8	1~8	1~6
LLT-0401	40	3~9	1.5~10	1~10	1~10	1~8	1~8	1~6
LLT-0402	40	7~20	3~22	2.5~25	2.5~25	2~18	2~18	3~12
LLT-0501	50	7~20	3~22	2.5~25	2.5~25	2~18	2~18	3~12
LLT-0502	50	9~36	4.5~36	3.6~36	3.6~36	2.8~25	2.8~25	4.5~18
LLT-0801	80	9~36	4.5~36	3.6~36	3.6~36	2.8~25	2.8~25	4.5~18
LLT-0802	80	20~80	10~80	10~100	10～100	6.5~56	6.5~56	5~40
LLT-1001	100	20~80	10~80	10~100	10～100	6.5~56	6.5~56	5~40
LLT-1002	100	25~100	20~100	15~150	15~150	8.5~80	8.5~80	6.5~55
LLT-1501	150	25~100	20~100	15~150	15~150	8.5~80	8.5~80	6.5~55
LLT-1502	150	55~225	30~250	25~250	25~250	18~150	18~150	10~100
LLT-2001	200	55~225	30~250	25~250	25~250	18~150	18~150	10~100
LLT-2002	200	90~360	50~400	40~400	40~400	28~240	28~240	20~160
LLT-2501	250	90~360	50~400	40~400	40~400	28~240	28~240	20~160
LLT-2502	250	130~5400	65~540	60~600	60~600	42~360	42~360	30~240
LLT-3001	300	130~5400	65~540	60~600	60~600	42~360	42~360	30~240
LLT-3002	300	220~800	110~900	95~950	95~950	70~600	70~600	54~450
LLT-3501	350	220~800	110~900	95~950	95~950	70~600	70~600	54~450

Flow rnge (m³/h) (accuracy class 0.2, 0.3)

型号	口径	粘度mPa.s
		0.3~0.8	0.8~2	2~15	15~400	400~1000	1000~2000	2000~3500
		汽油	煤油	柴油、机油	重油	高粘度液体
LLT-0252	25	3.5~8	3~10	2~10	2~10	2~8	2~8	2~6
LLT-0401	40	3.5~8	3~10	2~10	2~10	2~8	2~8	2~6
LLT-0402	40	8~20	5.5~22	4.5~22	4.5~22	4~18	4~18	3~12
LLT-0501	50	8~20	5.5~22	4.5~22	4.5~22	4~18	4~18	3~12
LLT-0502	50	15~36	9~36	7~36	7~36	6~25	6~25	4.5~18
LLT-0801	80	15~36	9~36	7~36	7~36	6~25	6~25	4.5~18
LLT-0802	80	30~80	20~80	15~80	15～80	14~56	14~56	10~40
LLT-1001	100	30~80	20~80	15~80	15～80	14~56	14~56	10~40
LLT-1002	100	40~100	25~100	20~120	20~120	18~72	18~72	14~55
LLT-1501	150	40~100	25~100	20~120	20~120	18~72	18~72	14~55
LLT-1502	150	88~220	57~225	44~220	44~220	38~150	38~150	25~100
LLT-2001	200	88~220	57~225	44~220	44~220	38~150	38~150	25~100
LLT-2002	200	150~360	90~360	72~360	72~360	50~210	50~210	40~160
LLT-2501	250	150~360	90~360	72~360	72~360	50~210	50~210	40~160
LLT-2502	250	180~540	135~540	100~540	100~540	90~360	90~360	60~240
LLT-3001	300	180~540	135~540	100~540	100~540	90~360	90~360	60~240
LLT-3002	300	250~800	220~900	180~900	180~900	150~600	150~600	110~450
LLT-3501	350	250~800	220~900	180~900	180~900	150~600	150~600	110~450