Description:FIELD OF THE INVENTION:
The present invention relates to a gas pressure handling system, and more particularly, a gas pressure handling system for regulating the pressure generated by the gases during pyrolysis in an existing pyrolysis unit.

BACKGROUND OF THE INVENTION:
The process of pyrolysis includes decomposition of material by application of heat in an inert environment. In the process of plastic pyrolysis, the plastic material and polymers are decomposed thermally leading to the formation of fuels and other hydrocarbon compounds. The organic material is transformed by thermal decomposition into gaseous components, carbon residue and pyrolytic liquid fuel.
The pyrolysis systems are usually fed with a random mixture of available waste plastic or waste polymers. The pyrolysis system breaks the large molecules of the polymers into small pieces by heating in anaerobic conditions with or without the aid of catalysts. In this process, the small molecules are also produced at random. These non-condensable fractions of small molecules are usually flammable hydrocarbons that are in gaseous form. This leads to the generation of a variable and fluctuating volume of gases. The volume of gases produced ranges from 7% to 15%. These gases are utilized to heat the reactors.
The reactor volume of the pyrolysis plants is fixed. However, sometimes the gases produced at higher temperatures in the range of 380? to 480? expand exponentially. The generation of these gases results in sharp pressure fluctuations in the whole pyrolysis system. This expanding gas volume becomes very difficult to handle. Further, the back pressure on the reactor may result in unwanted and dangerous leakage of hazardous gases from seals, feeding mechanism, etc.
There have been a few attempts in the art to regulate the pressure fluctuations in the pyrolysis units. The Chinese Utility Patent CN216303710U to Zhang Dongming and others describes a stable fuel gas supply system of waste tire pyrolysis system. The system has a gas pressure regulator module that is maintained stable by back pressure type nitrogen supply valve and back pressure type nitrogen discharge valve. The pressure of the back pressure type nitrogen discharge valve is set 100-200Pa higher than the back pressure type nitrogen supply valve.
The patent application WO2023126824A1 to Felisari Riccardo and others discloses a process and apparatus for pyrolysis of plastic material. The apparatus includes a first pressure control device and a second pressure control device for controlling the pressure in pyrolysis reactor; the devices being valves acting through feedback mechanism relating to the value of the pressure in the reactor. The first pressure control device receives pyrolysis vapors from second reactor and the second pressure control device restricts passage of residual gas leaving the condenser before sending the residual gas to the receiving unit.
The technologies known in art are not capable of handling a broad pressure range and also have a slower response to pressure fluctuations. There is a need for gas pressure handling system for pyrolysis units that offers safe handling of gases at any moment. There is a further need for a system that stops the reactor of a pyrolysis unit from going into negative pressure.

SUMMARY OF THE INVENTION:
The present invention describes a gas pressure handling system 100 incorporated with an existing pyrolysis unit. The system 100 includes a low pressure tank 105, a high pressure tank 110 and a pressure transmitter 115. The system 100 further includes a pair of ring blowers 120, a plurality of variable frequency drives (VFD) 125, a plurality of solenoid valves 130, 130’ and 130’’, a proportional valve (positioning valve / servo valve) 135, a plurality of expansion joints 140 and 140’, a programmable logic controller (PLC) 145, a pipe 150, a pipe 155, and an outlet pipe 160.
The system 100 is designed such that the low pressure tank 105 and the high pressure tank 110 are positioned for regulating the displacement of gas between them through the system 100. Accordingly, the low pressure tank 105 and the high pressure tank are connected through a plurality of pipes such that a pipe 150 emerging from the low pressure tank 105 further splits into two pipes. Each of these two pipes is further connected to a solenoid valve 130.
A pipe emerges further from each of the two solenoid valves 130 and further connects with an expansion joint 140. A pipe emerges from each of the expansion joint 140 and further connects with the ring blower 120. A pipe emerges from each of the ring blower 120 and further connects with the expansion joint 140’. A pipe emerges from each of the expansion joint 140’ and further connects with the solenoid valve 130’.
A pipe arises from each of the solenoid valve 130’ and the two pipes arising from the two solenoid valves merge together to form a pipe 155. The pipe 155 further connects with the high pressure tank 110. The pipe 165 emerging from the pipe 155 further connects back to the pipe 150 through a proportional valve 135.
When the pressure of the pyrolysis unit rises above a certain threshold, a signal is send by the pressure transmitter 115 to the programmable logic controller (PLC) 145. The PLC 145 in turn sends a signal to the variable frequency drives (VFD) 125. The variable frequency drives 125 increases the speed of the ring blowers 120. The ring blowers 120 lead to an increase in the speed of displacement of the gas between low pressure tank 105 and high pressure tank 110.
When the pressure of the pyrolysis unit falls below a certain threshold, a signal is send by the pressure transmitter 115 to the programmable logic controller (PLC) 145. The PLC 145 in turn sends a signal to the variable frequency drives (VFD) 125. The variable frequency drives 125 decreases the speed of the ring blowers 120. The ring blowers 120 lead to a decrease in the speed of displacement of the gas between low pressure tank 105 and high pressure tank 110.
When the pressure in the phase separator or the low pressure tank 105 is within the normal limit of 50MMWc to 300MMWC, a signal is send by the pressure transmitter 115 to the programmable logic controller (PLC) 145. The PLC 145 in turn sends a signal to the proportional valve 135. The proportional valve 135 is opened and the displacement of gas is carried out from the high pressure tank 110 to the low pressure tank 105 till the pressure of the pyrolysis unit is regulated at the set limit of 50 to 300 MMWC.

BRIEF DESCRIPTION OF DRAWINGS:
The objectives and advantages of the present invention will become apparent from the following description read in accordance with the accompanying drawings wherein,
FIG. 1a shows a perspective view of the gas pressure handling system 100 for pyrolysis unit in accordance with the present invention; and
FIG. 1b shows a block diagram of the gas pressure handling system 100 for pyrolysis unit in accordance with the present invention.

DESCRIPTION OF THE INVENTION:
References in the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
References in the specification to “preferred embodiment” means that a particular feature, structure, characteristic, or function described in detail thereby omitting known constructions and functions for clear description of the present invention.
The foregoing description of specific embodiments of the present invention has been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed and obviously many modifications and variations are possible in light of the above teaching.
Conventionally, the pyrolysis systems break large molecules or polymers, during which small molecules are also produced at random. These non-condensable fractions are usually flammable hydrocarbons in gaseous form, that is further utilized to heat the reactors. The variation in the volume of the gas generated results in sharp pressure fluctuations in the whole pyrolysis unit resulting in unwanted and dangerous leakages. The gas pressure handling system of the present invention regulates the pressure inside the pyrolysis system and the reactor and keep the system safe.
The present invention describes a gas pressure handling system incorporated with an existing pyrolysis unit. The gas pressure handling system regulates the pressure generated due to the fluctuating volume of gases produced during pyrolysis in an existing pyrolysis unit. A pyrolysis unit generally consists of a pyrolysis reactor, a heat exchanger and a phase separator. The pyrolysis process is carried out in the pyrolysis reactor, that generates oil vapors and non-condensable gases. These gases generated by the pyrolysis reactor are cooled in the heat exchanger. The phase separator separates the liquid oil and gas. This separated gas is then fed to the burners in the furnace to heat the pyrolysis reactor.
Now referring to FIG. 1a and FIG. 1b, a gas pressure handling system 100 (herein after referred to as “system 100”) incorporated with an existing pyrolysis unit in accordance with the present invention is described. The gas pressure handling system 100 is located after the phase separator of an existing pyrolysis unit. The gas outlet from the system 100 is further connected to the burners of the furnace that heat the pyrolysis reactor.
The system 100 includes a low pressure tank 105, a high pressure tank 110 and pressure transmitters 115. The low pressure tank 105 and the high pressure tank 110 are made of Mild steel (MOC). The capacity of the low pressure tank 105 is such that the low pressure tank 105 has a volume not less than 10% of the feed weight. Thus, for example, if the capacity of the pyrolysis plant is 12000 kg per day, the volume of low pressure tank is 1200 litre. The capacity of the high pressure tank 110 is such that the high pressure tank 110 has volume not less than 5% of the feed weight. Thus, for example, if the capacity of the pyrolysis plant is 12000 kg per day, the volume of the high pressure tank is 600 litre.
The pressure transmitters 115 are located at the phase separator of an existing pyrolysis unit. The low pressure tank 105 and the high pressure tank 110 are positioned such that the displacement of gas is regulated between them through the system 100. The low pressure tank 105 and the high pressure tank are connected through a plurality of pipes housing the components of the system 100.
The system 100 further includes a pair of ring blowers 120, a plurality of variable frequency drives (VFD) 125, a plurality of solenoid valves 130, 130’ and 130’’, a proportional valve (also known as positioning valve or servo valve) 135, a plurality of expansion joints 140 and 140’, and a programmable logic controller (PLC) 145 that is located on the control panel and connected to the pressure transmitters 115. A pipe 150 emerge from the low pressure tank 105 that further splits into two pipes. Each of the pipe is further connected to a solenoid valve 130. A pipe emerges further from each of the solenoid valve 130, and further connects with an expansion joint 140.
Subsequently, a pipe emerges from each of the expansion joint 140 and further connects with a ring blower 120. Thus, the low pressure tank is connected with the pair of ring blowers 120 through a pair of solenoid valves 130, followed by a pair of expansion joints 140.
Further, a pipe emerges from each of the ring blower 120 and further connects with an expansion joint 140’. Next, a pipe emerges from each of the expansion joint 140’ and is connected with a solenoid valve 130’. The pipe arising from each of the solenoid valve 130’ merges together to form a pipe 155, that further connects with the high pressure tank 110. Thus, the pair of ring blowers 120 are connected with the high pressure tank 110 through a pair of expansion joints 140’, followed by a pair of solenoid valves 130’.
The high pressure tank 110 has an outlet pipe 160 that further splits into three ducts. Each of the three duct is regulated through a solenoid valve 130’’ each. Two ducts emerging from the outlet pipe 160 are further connected to the burners of the furnace that heat the pyrolysis reactor. The remaining one duct is further connected to the flare.
A pipe 165 emerges from the pipe 155 and is further connected back to the pipe 150 through a proportional valve 135.
Now the operation of the gas pressure handling system 100 in accordance with the present invention is described. The displacement of gas between the low pressure tank and the high pressure tank is regulated through the system 100 ensuring maintenance of pressure of the pyrolysis unit at a set value. If the pressure in the pyrolysis unit rises above 50 MMWC, the pressure transmitter 115 records it and sends a signal to the programmable logic controller (PLC) 145. The PLC 145 in turn sends a signal to the variable frequency drives (VFD) 125. The variable frequency drives 125 triggers the ring blowers 120 thus controlling the speed of the ring blowers 120. Thus, the rise in the pressure above 50 MMWC, leads to a consequent rise in the the speed of the ring blowers 120. The ring blowers 120 control the speed of displacement of the gas between low pressure tank 105 and high pressure tank 110. As a result, the gas displacement is controlled.
When the pressure in the phase separator or the low pressure tank 105 rises above 300 MMWC, is higher, the pressure transmitter 115 sends a signal to the programmable logic controller (PLC) 145. The PLC 145 in turn sends a signal to the variable frequency drives (VFD) 125. The variable frequency drives 125 trigger the ring blowers 120 leading to an increase in the speed of the ring blowers 120. As a result, the speed of gas displacement from the low pressure tank 105 to the high pressure tank 110 is increased.
On the other hand, when the pressure in the phase separator or the low pressure tank 105 decreases, the pressure transmitter 115 sends a signal to the programmable logic controller (PLC) 145. The PLC 145 in turn sends a signal to the variable frequency drives (VFD) 125. The variable frequency drives 125 decreases the speed of the ring blower 120. As a result, the speed of gas displacement from the low pressure tank 105 to the high pressure tank 110 is decreased.
The normal pressure of the pyrolysis unit is set at the limit of 50 to 300 MMWC. When the pressure in the phase separator or the low pressure tank 105 is normal, the pressure transmitter 115 sends a signal to the programmable logic controller (PLC) 145. The PLC 145 in turn sends a signal to the proportional valve 135. The proportional valve 135 is opened, and the displacement of gas from the high pressure tank 110 to the low pressure tank 105 takes place. The displacement of the gas is carried out till the displacement of gas is maintained and the pressure of the pyrolysis unit is ensured to be between the set limit of 50 to 300 MMWC.

EXAMPLES:
Only a few examples and implementations are disclosed. Variations, modifications, and enhancements to the described examples and implementations and other implementations can be made based on what is disclosed.
Examples are set forth herein below and are illustrative of different amounts and types of reactants and reaction conditions that can be utilized in practicing the disclosure. It will be apparent, however, that the disclosure can be practiced with other amounts and types of reactants and reaction conditions than those used in the examples, and the resulting devices various different properties and uses in accordance with the disclosure above and as pointed out hereinafter.
Example 1: Operation of the gas pressure handling system during high pressure conditions
1) The pressure P1 in the low pressure tank was recorded by the pressure transmitter and it was found to be 320 MMWC.
2) The pressure transmitter sent the signal to the variable frequency drives to increase the speed of the ring blowers.
3) The variable frequency drives increased the increased the speed of the ring blowers in proportion to the increase in the pressure P1.
4) As a result, the speed of gas displacement from the low pressure tank to the high pressure tank was increased.
5) Now the pressure P2 in the low pressure tank was again recorded by the pressure transmitter and it was found to be 150 MMWC.
6) The pressure transmitter sent the signal to the variable frequency drives to decrease the speed of the ring blowers.
7) The variable frequency drives decreased the speed of the ring blowers proportionally to the decreased pressure P2 that was recorded.
8) As a result, the speed of gas displacement from the low pressure tank to the high pressure tank was decreased, and the pressure was maintained at 150 MMWC.

Advantageously, the gas pressure handling system 100 enables handling of the gas volume in the pyrolysis unit. It further enables handling of the back pressure in the reactor. The system helps to maintain the pressure of the reactor as low as 50 MMWC. The response time of the system is 30 sec. As a result, the gas pressure handling system 100 offers safe handling of the gases produced at any moment. The system stops the reactor going into negative pressure. The negative pressure allows atmospheric air to enter into the hot reactor and the possibility of the fire inside the reactor is avoided. Thus, the gas pressure handling system ensures safety of the pyrolysis unit, human life and environment.
The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others, skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated.
It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the scope of the present invention.
, Claims:CLAIMS:
We claim:
1. A gas pressure handling system 100 incorporated with an existing pyrolysis unit, characterized in that the gas pressure handling system 100 comprising a low pressure tank 105, a high pressure tank 110, a pressure transmitter 115, a pair of ring blowers 120, a plurality of variable frequency drives (VFD) 125, a plurality of solenoid valves 130, 130’ and 130’’, a proportional valve (positioning valve / servo valve) 135, a plurality of expansion joints 140 and 140’, a programmable logic controller (PLC) 145, a pipe 150, a pipe 155, and an outlet pipe 160.
2. The gas pressure handling system 100 as claimed in Claim 1, wherein the low pressure tank 105 and the high pressure tank 110 being positioned for regulating the displacement of gas between them through the system 100.
3. The gas pressure handling system 100 as claimed in Claim 1, wherein the low pressure tank 105 and the high pressure tank being connected through a plurality of pipes housing the components of the system 100 such that
a) a pipe 150 emerging from the low pressure tank 105 further splitting into two pipes;
b) each of the two pipes further being connected to the solenoid valve 130;
c) a pipe emerging further from each of the solenoid valve 130, and further being connected with an expansion joint 140;
d) a pipe emerging from each of the expansion joint 140 and further being connected with the ring blower 120;
e) a pipe emerging from each of the ring blower 120, and further being connected with the expansion joint 140’;
f) a pipe emerging from each of the expansion joint 140’, and further being connected with the solenoid valve 130’;
g) the pipe arising from each of the solenoid valve 130’ merging together forming a pipe 155;
h) the pipe 155 further connecting with the high pressure tank 110; and
i) the pipe 165 emerging from the pipe 155 being further connected back to the pipe 150 through a proportional valve 135.
4. The gas pressure handling system 100 as claimed in Claim 1, wherein the system 100 operating when the pressure of the pyrolysis unit rising above a certain threshold such that
a signal being send by the pressure transmitter 115 to the programmable logic controller (PLC) 145;
the PLC 145 in turn sending a signal to the variable frequency drives (VFD) 125;
the variable frequency drives 125 increasing the speed of the ring blowers 120; and
the ring blowers 120 leading to an increase in the speed of displacement of the gas between low pressure tank 105 and high pressure tank 110.
5. The gas pressure handling system 100 as claimed in Claim 1, wherein the system 100 operating when the pressure of the pyrolysis unit falling below a certain threshold such that
a signal being send by the pressure transmitter 115 to the programmable logic controller (PLC) 145;
the PLC 145 in turn sending a signal to the variable frequency drives (VFD) 125;
the variable frequency drives 125 decreasing the speed of the ring blower 120; and
the ring blowers 120 leading to a decrease in the speed of displacement of the gas between low pressure tank 105 and high pressure tank 110.
6. The gas pressure handling system 100 as claimed in Claim 1, wherein the system 100 operating when the pressure in the phase separator or the low pressure tank 105 being within the normal limit such that
a signal being send by the pressure transmitter 115 to the programmable logic controller (PLC) 145;
the PLC 145 in turn sending a signal to the proportional valve 135;
the proportional valve 135 being opened;
the displacement of gas being carried out from the high pressure tank 110 to the low pressure tank 105 till the pressure of the pyrolysis unit being maintained at the set limit of 50 to 300 MMWC.

Dated this 08th day of September 2023.
For MY INDIFUELS PVT LTD

Mahurkar Anand Gopalkrishna
IN/PA-1862
(Agent for Applicant)