LNG LPG Liquid Compressor Reciprocating Piston Compressor for Gas Station Loading Unloading

• Customization: Available
• After-sales Service: Provide After-Sales Service
• Warranty: 18months
• Lubrication Style: Lubricated
• Cooling System: Water Cooling
• Cylinder Arrangement: Balanced Opposed Arrangement
• Cylinder Position: Angular
• Structure Type: Closed Type
• Compress Level: Double-Stage
• Type: Zw-1.5/16-24
• Power: 18.5kw
• Inlet Pressure: 1.6MPa
• Outlet Pressure: 2.4MPa
• Max Differential Pressure: 0.8MPa
• Dimension (mm): 1000*680*870
• Transport Package: Fumigation Wooden Box, by Sea
• Specification: 1600x1100x1400
• Origin: China
• HS Code: 8414804090
• Production Capacity: 500sets/Year

Product Description

Xuzhou Huayan Gas Equipment Co.,Ltd, exporting , piston compressor, , gas cylinder and nitrogen generators with good quality and low price.

Piston compressor is a kind of piston reciprocating motion to make gas pressurization and gas delivery compressor mainly consists of working chamber, transmission parts, body and auxiliary parts. The working chamber is directly used to compress the gas, the piston is driven by the piston rod in the cylinder for reciprocating motion, the volume of the working chamber on both sides of the piston changes in turn, the volume decreases on one side of the gas due to the pressure increase through the valve discharge, the volume increases on one side due to the reduction of air pressure through the valve to absorb the gas.

Compressor for unloading and loading
Product description
This ZW series of oil-free compressors is one of the first products produced by our factory in China. The compressors have the advantage of low rotating speed, high component strength, stable operation, long service life and convenient maintenance. It is consist of compressor, gas-liquid separator, filter, two-position four-way valve, safety valve, check valve, explosion-proof motor and base etc. It has the characteristics of small size, light weight, low noise, good sealing, easy installation and easy operation.
This compressor is mainly used for unloading, loading, dumping, residual gas recovery and residual liquid recovery of LPG/C4, propylene and liquid ammonia. It is widely used in gas, chemical,energy and other industries, and is a key equipment in gas, chemical, energy and other industries.

Note: In the process of unloading, the compressor pressurizes the gas from the storage tank and then presses it into the tanker through the gas phase line, and presses the liquid from the tanker to the storage tank through the pressure difference of the gas phase to complete the unloading two process. When the gas phase is pressurized, the temperature of the gas phase will rise. At this time, it is not necessary to force it to cool, because if the gas phase is compressed and then cooled, it is easy to liquefy, and the pressure difference of the gas phase is difficult to establish, which is not conducive to the replacement of the gas phase and the liquid phase. In short, it will prolong the unloading process time. If residual gas recovery is required, during the residual gas
recovery operation, a cooler can be selected for forced cooling of the gas phase, so as to recover the residual gas as soon as possible.
The loading process is the opposite of the unloading process.

Propane-Butane Mix Compressor

Number	Type	Power(kW)	Dimension (mm)	Loading or unloading (t/h)
	ZW-0.6/16-24	11	1000×680×870	~15
	ZW-0.8/16-24	15	1000×680×870	~20
	ZW-1.0/16-24	18.5	1000×680×870	~25
	ZW-1.5/16-24	30	1400×900×1180	~36
	ZW-2.0/16-24	37	1400×900×1180	~50
	ZW-2.5/16-24	45	1400×900×1180	~60
	ZW-3.0/16-24	55	1600×1100×1250	~74
	ZW-4.0/16-24	75	1600×1100×1250	~98
	VW-6.0/16-24	132	2400×1700×1550	~147

Inlet pressure:≤1.6MPa
Outlet pressure: ≤2.4MPa
Max differential pressure: 0.8MPa
Maximum Instantaneous Pressure Ratio:≤4
Cooling method: Air cooling

The unloading volume is calculated according to the inlet pressure of 1.6MPa, the outlet pressure of 2.4MPa, the inlet temperature of 40 ºC , and the density of propylene liquid of 614kg/m3. When the working conditions change, the unloading volume will change accordingly, which is for reference only.

 Piping and Instrumentation Diagram of gas unloading  
 Liquid delivery
At the beginning, open the liquid phase pipeline between the tanker and the storage tank. If the liquid level in the tanker is higher than the storage tank, it will automatically flow into the storage tank. When the balance is reached, the flow will stop. If the liquid phase of the tanker is lower than the storage tank, directly start the compressor, the four-way valve is in the positive position, and the gas is extracted from the storage tank by the compressor and then discharged into the tanker. At this time, the pressure in the tank car rises, the pressure in the storage tank drops, and
the liquid in the tank car flows into the storage tank. (as shown below)


 Surplus liquid recovery
The residual liquid recovery process is the opposite of liquid transfer. After the liquid is delivered, the four-way valve should be reversed, and the dotted line in the figure is closed. At this time, the remaining gas in the tanker is inhaled by the compressor, pressurized and then discharged to the storage tank until the pressure of the remaining gas drops to no recovery value. When recycling, pay attention that the compressor pressure ratio and exhaust temperature cannot exceed the allowable values.

The working principle of the four-way valve
                   


Pull the handle of the four-way valve, when the four-way valve is in the position shown in Figure a, the A side is the intake air, and the gas flows from A to B, through the pipe, the intake filter part, the compressor intake pipe, the compressor, The compressor discharge pipe, the D end flows to the C end, and the C end is the exhaust end.
When the four-way valve is in the position of Figure B, the C end is the intake air, and the gas flows from the C end to the B end, through the pipe, the intake filter part, the compressor intake pipe, the compressor, the compressor exhaust pipe, and the D end It flows to end A, which is the exhaust end.


Reference example for selection and calculation of Propane-Butane Mix unloading compressor
.Selection of compressor inlet and outlet pressure
Saturated vapor pressure of Propane-Butane Mix at 20~36ºC

Temperature(ºC)	Atmosphere	Temperature(ºC)	Atmosphere
20	8.4585	30	11.512
22	9.0125	32	12.212
24	9.5940	34	12.943
26	10.2040	36	13.708
28	10.8430

In the case of high temperature, the saturated vapor pressure of Propane-Butane Mix is high, so the 16barg (inlet pressure)-24barg (outlet pressure) model is selected to meet the use environment when the temperature is high.
^{Note: The unit of pressure is kg/cm2}

 

• Compressor Flow Calculation

The specific flow calculation is more complicated and needs to be finally determined according to the calculation formula and experience. Only a simple calculation method is introduced here.

1. Calculate the volume of the tanker
According to the provided operating conditions, first determine the total volume flow required to unload the 15-ton Propane-Butane Mix tanker in 1 hour.
The specific gravity of Propane-Butane Mix is 0.618, so the volume of 15 tons of Propane-Butane Mix is: 15 ÷0.618=24.272m3; and since the tanker is not allowed to be full, it is generally about 80% of the tanker's volume. The volume is 24.272+15×0.2=27.272, so the volume of the tanker should be 30m3.


2.Calculate flow
When the compressor is unloading, the pressure difference must first be established before the Propane-Butane Mix can be unloaded from the tanker to the storage tank. Generally, the time to establish the pressure difference is 15 minutes, so the actual unloading time is only about 45 minutes, that is, the required displacement is 30 ÷ 45 = 0.66667m3/min; and after the gas is pressurized from 16kg to 24kg by the compressor, the volume will be reduced to about 0.66667 (16 ÷ 24) of the original volume, then the compressor displacement is: 0.66667 ÷ 0.66667 =1m3/min

According to the above calculation, the compressor model is selected as ZW-1.1/16-24